Initial Graphics Exchange

Specification (IGES), Version 3.0

Brad Smith

Joan Wellington

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Manufacturing Engineering

Automated Production Technology Division

Gaithersburg, MD 20899

April 1986

U.S. DEPARTMENT OF COMMERCE

NATIONAL BUREAU OF STANDARDS
ACKNOWLEDGEMENT

Version 3.0 of this IGES Document is the joint effort of a large number of people who comprise

the IGES Organization. Individually, these experts have shown tremendous personal commitment.

Collectively, they have demonstrated a spirit of cooperation that is unique in consensus standards

development. Each company has ample reason to be proud of the contributions of the IGES

member they sponsor.

While individual contributions are too numerous to mention, I wish to recognize the efforts of my

Secretary, Mrs. Mary Marello, for the word processing of this Document. Her accuracy and

attention to detail are second only to her dedication in making IGES the useful tool it is. My

personal thanks to Mary for an outstanding job.

Bradford Smith

Chairman, IGES
73 at 73 B rH

(0 rH 44 •H CN U ©

<0 3 00 O rH CN rH at o o

O CN 55 10 rH tn 44 © a> •rH B

at 43 rH > tn co at 44 44 CN O' Z

73 rH (0 at H o rH © « © B O o B 03 a -Q •a at SO no o at rH 44 fH rH rH rH Q

at <0 73 •o at co H <0 br Q © © © © B •H U S

ki 3 C < a> b < at B •D Q rH a rH 44 45 a H (0 c >1 44 •• © • © V U B O

O (0 ••to no 45 •• at 73 < 44 •• £3 •• in rH 44 1 44 +t > at U 45 73 O CO rH 73 c 44 44 • © © 44 o

4-1 at cj < H at at < M © C •• c CN Q rH c 44 B

at <a Or 10 Hf Qr'U at 44 s © © © © © U

kt u >1 •• •• u "O >1 •• O' c e 6 © G O •• a Ih b a

73 10 3 44 44 44 at rH 44 •• 44 to at o G 44 £ © © © W B M o C C •H k 44 c Or G o O O O CQ C •• Or a

% at o >. at at m o 3m C at G O C o tH © B B ©

73 rH 10 44 G G Hf 44 at G at o % <a rH C O'

>4 X *h G 6 •• rH -H G 6 H o o k k k © tH M © c

* <0 >4 44 O O rH k 44 G O •rH O' m in o 45 45 rH O' ©

73 44 rH COB o O c o O 44 k O' O 44 o C 43

k-v CO at at in at cn at o c o © © © © Ih 44 44 © CJ 73 —

ca u • O k 44 rH k at O' c c c V 44 3 a 43

at B •H -H 44 O *73 O * <H * 43 •rH -r4 °*H c 44 O IH © CJ •• 3 45 44 O O' CN O' Z CN o O' at at rH rH rH •rH © © OH -rH O' rH C at 44 C o B CN 44 c fH 44 MH c - H-

•rH O' at 44 at k at rH 44 at at at •rH k k k © « k © CN Z

44 c «kt a c ih c 73 •« ca c c rH rH © © © k pH 45 45 » 45 c <0 o at •H -H O -H 73 O -rt -H rH at O' O' O' © © 44 Or 45 u © © o 43 43 tJ rH * rH < CN t-3 rH rH Q k © © © O' a © Or C C

<j 73 V a O rH at Or Or Or © 45 Ih © r -rt -rH at 44 44 • •> k> O <k •• % % <k k •c O' • Or 0 * 44 O' kr 43 f-H rH

kg •• c o c at at b at at ao at at at at <0 00 43 43 43 to tH © O' < •H at at c o O' O' O' O' rH O' O' O' O' Or rH 44 44 44 « 43 G s IH (0 C U U

Eh 3 t-i 44 -rH 10 10 73 <0 t0 rH to to to (0 s C C rH 44 © tH o © © < O' 04 C >444 Or Or 10 Or Or Or Or Or Or 43 6 © © © c cH © Or © •H 44 44 3 at s O 10 3 at ca 44 kg © © © © © o Or 44 © ©

02 kj <0 U S <0 44 44 kl 44 44 at JS JS 8 43 43 «IH © 44 44 44 44 © Go © 44 Or G G

63 X o m © so 0) Or 44 44 r* 44 44 rH 44 t4 IH U O 44 O rH (0 4J © B © ©

at at at 44 lr hr O U H >, X X rH X B c at •rH 3 3 C <*H Or U SO u © u u

O' B JC 3 45 HH 4JH •H 44 HHCN •H O at 9 u 43 o o •rH © °tH © © © © c * ,—k Eh 43 -U <44 44 IH <H at co * CO o 44 44 O 44 <HH *4H <0 OH % 02 MH rH fc © Or Or

fO (N 73 •H B >1 o 44 c CN CO CJ 43 • ta « at 9 k kin k •> 44 k k CN - at * k k k © k H M k k CN fe CO cj O' * tn o nnon cn *H tn co cn 43 co cn tn CO CO tn § rH <N< 1 44

• 73 1 C 73 1 l - l 1 44 i t co i 1 1 <D i I 1 O' l CN • • • CN -rH • e cn M cn at at CN CN rH CN CN C CN CN g CN .JJ CN CN u CN CN CN C CN in in in u CO CO

0 k> m ca O at U o t4 0 0 • © H o • If 73 at at 3 at at k at at to to a at c at m 3 © © © <o © u CN CN CN IH pH CO CO

• >t ih a-t H H O H rH H H H fa H C rH fH cr8 f-H rH rH © fH 3 3 Or CN 43 at at 43 43 O 43 B 43 O 43 43 ^43 <0 43 rD to 43 43 43 © 43 O o o O' G u o

• B *0 Ih 43 10 <0 B f0 rH <0 OH (0 <0 B to o <0 m u © © © 43 © © © 9 -r| M to to CN EH EH eh Eh Eh Eh Eh Eh & Eh Eh Eh Eh fv CO CO CO br C/3 CO

a>O'a

CNcn

tn

l <T> co o\

co om

co

in m

co cn

O'

O'

O' m

©

-k> (0c

M

o

cn<

©

O'

99©

&

o

3

ato

c

at i -u c

atuO

Iklat XI

O C3 © f-H c © ©

O © s b9 © > 44 CJ 45 © 8 M -rH ©

O' U O' O' O' rH £ o © ©

© © •« © 44 43 © z

vc- O' tH s © 45 44 C s

oo © IH O' c CJ B O

a V fH •H C © -rH 73

^-s 44 ©• rH oo © 44 44 kt © © 0 © B Eh © Or O

C*=J 44 B B BBS 73 C O' B B rH -fH 9

•H © i—1 pH rH CN • C C o © kl o © © oou 44 o f-H H © © D O ©

a tH C C o o c c o ^ C f-H O' so 43 < a TJ o o rH iH fl -H © _ © © c •• © 44 •H C B •rH °rH © •• so 43 T3 B © 43 73 ^ 4J •H in 44 44 © © rH U a 44 -rH 43 Or 73 o c < • •rH *rl no na © 44 9 • % »H 9 73 CJ © O 73

• *H Eh no in na <a O O 44 SO O « 45 3 ki IH 9 < CO U < rH • -a <o CJ CJ c c rH rH OcB o © O •• O' 44

PU K -o 3 CN < < © o i—

-*H © S MH c 9 m © •• c CC © O B B B 44 44 e (J o br kr ih •rH rH kl • cn O 4J w IH 43 c c © \ MH B O' O rH © © • •h cn *H a T3 fq 73 O O rH 73 © MH 45 U Or • ih

cn u 3 <a IH IH br br U © SO 73 ki Or 0) 44 to ©

U -H O’ to O O B B B O © IH IQ M © © 44 © 44

(U Cm © B u * 9 t-3 O OrlH IH © to © 73 © > IH s T3 <0 T3 so 9 O 0143 44 B © rH G

IH T3 © © © © © t—

U 73 cn fl O © <a »J © fl © o rH 43 45 a/ ai a> b <d ©voO'incoo'OrHinvoo'Ocn © kt < IH 3 i—

u -rl kt CO O' br a 44 44 MUM e 73 ^NNcnNkfinininintfl©© 45 •H B © © © ca kMH © B u c o © o G'N<'N, 'N, N, 'N, kt|'<N''N, HrN, 'k|, 'N' 44 .C Or* 73 04 cn Or O u © w © © T) 'O T3 44 Z 3 4J O • © 44 M 43 IH cn 44 44 rH fH rH ca c © 4J , O •• Hf © k

CJ CJ © © 3 3 3 >lVO 44 rH jj to rH • o CN kr B rH 1—

O O OMf © © N* B rH G 1 CN JS 1 © < • © © 43 45 45 1 O' rH • 4J 3 B -H CN • 44 CN 44 in •O 73 (0 (0 SO •N* © © rH (Q MH M rH CN c

• B Or 73 a 73 O ai kl © -rH CN in CN O rH 00 HCNtnHCNtnNHMtnNin • u kl rH 4J rH • o rH O

• • CO f—

HHtn TL 73 1 1 1 1 1 1 1 1 1 1 1 1 CN o o -rH O cn A O br 43 Or CN CN | | 1 1 i no 73<«i:«*:aacameQUCjucjcj 1 to vm 45 <4 ca ca © • © B B B cn cn 4 4 4 <0 < CJ CO Eh .J cn EH

atO'

<a 04

in

(N
CN 8 O

B * O 44 8 8

as B E-l B z 8 jj

e-» B HJ» Oj LTt * u z X

0-j 03 8 8 B CN Q B W 45 03 O z B •H Q bl B 03 o o o + 03 B 8 x ^ « 8 4J 44 44 H o Q

2 2 Zb o z 44 8 O o

B B B Q 44 o B B + 4J 4J

4J HrIHfO 8 o

o o o B Z O Z B rH 4J B 8

44 44 44 O as B + Eh + w 03 4J 44 Eh •8 nfliif «u Q b a 09 BBS Pa 03 8 B B O' B 03 B 45 X >1 N B + o c a -U ZZZTJ 03 03 4) 41 41 id 45 8 0J> 8

B B B B B 8 O' O' CP 43 O' O' c c c u c 45 C 45 © 4) 4) © 4* © <13 <13 ITS (0 O' <0 O'

CP CP O' CP O' O' 43 43 45 .. JC C -C c

C C C C C C U CJ U CN u 10 CJ m

<TJ (0 <TJ <T3 © © z A JS

43 43 43 45 43 45 00 0« #0 4- •• CJ .. CJ T3 u u u u (J o »H i— i—

z <N

4* z z z z 4 •• + •• 3 •e oc oo oo •e •e + + + + VO (*» Z 45 C rH CN CO CO in co co co C

•H 45 ® 45 •H

4J Qli jjj) Qj) ^ 4> 45 ® © 45 © C e s H

c c c e e c C C C C C °H °r*4 °H o •H “H *H »H •H •H •H *H »H °H rH •—J HI 'o u T5 H H H H rH © rH H H 6—i H 1-4 4) S3 We we u H u u u u u we b We we ke we we 05 05 45 JZ < •H <D <D QJ QJ 41 4) 01 0) 4) 45 4-5 4J 4J 4J H 3 44 44 44 44 4J DU 35 3J 35 35 45 45 45 < O' © 4* © © 4) *4 4> <18 <12* di <D a £ £ «b a 4* a a a a 6 e s 6 e s «s <0 <0 OS Ufi <T3 <T3 <13 <T3 03 B © (0 <0 <0 <13 we We U w We We We We U « We U we we We 10 (0 10 a 4» <13 flj flj <13 10 O <0 (8 (0 <0 10 a a a v

a> OtaaQ< Doe a a a a a U

c «> * * m

<0 * Cs Ik. * © * <* %> *b Cfc CO CN CN £ CM (N <N IN CN 0»<N CN CN CN CN 0 O 0 u • o o • • c • • e e « r~ 00 00 ov

ro co co co ©• 10 <V in in in m 0 0 0 0 NNNOI NJSN^. CN CN CN CN B «s CN CN CN

CO CO CO CO CO CO 05 nrnpciz <*J° =*• N*

‘O a 4* o o o u O £3 o -w O O O O H*> o o o u

<U QJ CIS QJ © iO 4) 44 Qj> 48 QJ QJ © 05 45 45 45 TO WS TO) 05 05 03 03 03 03 03 03 03 03 03

45 O CN CO o rH O*

o» o\ O O o CN CN CN

as a

rH CN CN CN CN CN CN

B B 8 z Z >i T3 z B B 03 B a 03 we B B 03 •—o CN Q HCNQ 44 3

1-0 CN Q 03 03 B 03 03 b c

03 03 B Q Q Q Q 05 <we 'O D O 8 8 O 8 8 0 H c 8 8 O 44 44 © CN

10 44 O O O O £ 8 o © 44 44 B <W» 4J 8 <0 8 44 44 B 03 03 C We we M 03 8 8 Q 8 8 Q © ©

8 8 • Q 03 03 B 03 03 B © 4J 4J

03 03 B Q Q Q Q 45 vwe V4H we a p B B © B B © 4J © ©

45 B B 45 O' O' 1 P O' © © c © © C © © ©

<WI © © C C* CP flJ O' O' © O' (0 4J 4J

0] O' O' <0 C C 45 C C 45 c © <D <D C C 45 © © CJ © © CJ © c

8 ns as u 45 45 45 45 45 H © ©

45 45 CJ CJ .. CJ CJ .. CJ rH Q Q

8 CJ CJ •• rH pH

rH •• •• + •• •• + •• 41 O • • •• 4J •• »«

NO)Z cn <n Z rH 3 O oo o> u m CSPlZ O

4) 45 © © © © © © © 44 © ©

CO E © © © c c c c c c c c c C H c c c *»H °«H °H H H H •H 44 H **H M otJ *H “H »h rH rH rH H H H rH © H H H we •• we W3 U U W3 W3 U We H 0 We We C 3 we M we © © © © © © © <WI • © ©

£ O © © © 44 44 44 44 44 44 44 0 4J 4J 3 a 44 44 44 © © © © © © © © © ©

rH ^ © © © £ £ £ £ £ £ £ 44 O' £ £ o £ £ £ <0 as © <0 <T3 <0 © © >1 © ©

C5 T3 <o <d <0 U WJ We U u we u Hi-4 43 Wi Wi C Wo ws we © © © C0 c0 <TJ © B © h O <0 <0 05 05 US <TS <TJ a a a a a a a os Q 4| a a

£ a a a Eh cn ©

W 45 ^ to ^ fe * »Z - 3 4l * * Z JG o o o H H H CN 8 CO 4J <D CO CO

4J H H H H H H rH rH rH rH rH <TJ H rH 8 rH

%> 000 000 000 • o • 44 03 • rH • CN O CO CO CO CO CO CO CO CO CO CO 4J CO UJ CO © CO B

• 44 0 0 0 0 0 0 0 0 0 0 0 • C5 *43

CO <o CO CO CO CO CO CO CO CO CO 8 CO 0) CO -re CO 4J

o 8 0 0 0 0 0 0 0 0 0 • rH • 43 • 00 • <TJ CO CO CO CO CO CO CO CO CO CO CO 8 cn Eh co >i<o a

• JZ •

*t> <** ««r W E nr anr > ra O II o

O o o o O O C4 U (5 U O 44 CJ O CN O rH

45 as © © © <y <d <U © © © © <44 © © B © 44

03 03 03 03 03 03 03 03 03 03 03 03 03 03

in m VO 00 CN VO VO 00 00 GO o> CN CN CN CN CN CN

cj u u

B B

~ ~ B B B S 1-5 CJ CJ 8 f—5 f—l O B B B Z Z Z N ea BOO o O B i—5 i-S r-5 Z b a Za rH B Z Z 44 0 0 0 z z z

B B o sh ca 44 44 z B B B HHNHUOHH 2 *H Z Z z z z z z z

M X B B B 63 B MrH^5X>iaSXZZXZ 2 Z X >1 B Z Z Z X X N

J4 4* B i-5 B B B 8 Z Q Z i-5 i-H i-l « 03 • B HHKZ >H z as as m z z z as as as

CJ CJ u 44 © o ^—

,—

rH B B B XXMBB >• n b X 8 csj as X >H N • 3 3 Q 44 O 44 44 o o 8 U BBS OObb b B S BBS

41 44 B © 44 z o o o o O O 44 44 O O O O OOO 44 44 X B S o > 8 8 44 44 44 ©004444 00440 u O 44 44 © O O O 44 44 44 © © o BOO s B 444444 BB4J 44 44 44 O' 4J 44 44

41 41 44 c O » N o o BBS B B N X B 8 BBC • • © © o X B B © © 4J i—) 63 r-5 BBS XXQSBSS X- >1 B X >1 © • - • 55 X N

> > S i-5 B O' O' Z Q Z xx n « as> xnkx 8 n as as 45 x x in as a: as o o r=j 44 © © G c 8 B BOB BSBBB ©BBSS a p * O

63 © © O' O' © © rH &a © O' a> © © Q a o' e c 43 45 Z Q © © © ©©©©©CPC©©©© CP (U 4> CD <>« <D<D<UQJ<D<D

43 45 B 4a e © © CJ CJ 8 8 ^ O^I Q) O' O' O' O' O' C © O'O'O'O* c O' 0*^-* O' O' O' O' O' O'

44 44 © © & 43 g e c CCCCC©43CCCC © c c c — c c c c c c © <44 43 CJ CJ •• •• 0) <0 fiS <TJ ©©©©©45CJ©©©© 43 <TJ ITS <TJ 8 <TJ<T3<T3<TJ<T3<T3 © © O' © U Q CJ O' O' 45 45 XS 45 45 45 45 43 0 43 45 43 43 O 43 43 45 — jz jz jz x: x: jz

i O' O' c c OO O* + + c e cj cj cj OOOOO ••OOOO uuu- uuuuuu

C c © © •• X 6<S CO 03 © <Q •• 1—5 •• © © 43 41 X + + + + 45 •• #o •• M «• M H H CJ 1 H M t* M <1> - - - CJ M M H M M M

'O 45 43 CJ E4 + < < < < CJ CJ CN CN CO ooooozo©©©© C 0) 0) <D 2 <D<D<D<D<D<D © CJ CJ B < + + + + 4> H- zzzzz+zcccc •H C C C + C C C C C C 3 M + O «H CN N1 •• o« H H rH + + + + + O 51 -H *-H *»H -*H rH •H -H -H O •H *^H H H **H *H C •• •• iH C O' <?—5 M r-5 iH CN (O z z z iniOXOOOlHXHHHrt rH rH rH rH rH rH rH rH rH rH

•r4 CO CO o Wl 44 © 1-1 © © © © © © © © © © ©©©©©©© 41 UUI4 a» H U We <D U U U H U H c © « C 44 c c c C C C c c c c ccccccc©©©© 4J 0) HMD c <D<D<D<D<D<D o C c 1-5 a iH -H i4 i-5 •H i-5 H •H "4 "H -5 15 -5 -5 15 15 15 4J 4J 4J *J a) -u -eJ -eJ -*h D D D D DU

u

<

E4

ss

asw

T3©HHHHH ID © 4) 4) ease

4J 4) 4) i a a e ©©©©©© ££££££ We Wl U we U We we we wi we we we WiWeWiWeWtWiWi<T3<T3<T3<T3 Wi © © <TJ we <TJ <TJ <TJ <T3 <T3 <TJ •H We We © © B © © © © © <D<D<D<D<D 0><D<D<D<D<D<DWiWiWiWi <T3 Wt Wi Wi QJ Wi u Wi Wi Wi Wi 3 © © 44 43 © •u 4J AJ 44 44 44 44 44 44 4J4J4J4J4J-W>4J<T3<T3<TJ<T3 D4 <T3 <TJ <TJ 4J <TJ <0 <T3 <T3 <T3 03 O’ 44 44 © 44 £ © © © © © © © © © © ©©©©©©©aaaa a a a © a a a a a a

© © © £ © £ £ £ £ £ £ E E E E £££££££ 4J £

we £ £ © •O 44 <TJ © © <TJ <TJ ITS <TS <T3 <T3 <TJ <TJ<T3<T3<T3<T3<T3<TJ4J4J4J4J CO 4J 4J 4J 03 AJ 4J 4J 4J AJ 4J

<0 B <TJ 8 Wl TJ U3 We Wa Wl we We wo wa Wj wi wi UWiWiWiWiUUXXXCQ u X X X Wi X X X X X X © U N Wl N flj © >. <T3 <0 03 <TS <TJ © © © © © <T3<T3<T3<T3<T3<TJ<T3<D<D<D<T3 H © © QJ iTJ QJ QJ © © © ©

O' <T3 b <T3 8 a cn Da Pj CU a a a a a a a aaaaaaac c c -4 <4H c c c a C c c c c c

S3 a a *> © e c ce ©

43 «t °cH «6 H **• rH 4J CN CN CN CN CN ^ ^ <NCNCNCN<N<NCNCNCNCNCN CN 2 2 2 2 CN CN <N <N CN CN O m <ts m <ts 0 « © e> 0 • • e • rH • rH CO 50 C VO vo HHHHH <N<N<N<N<N<NCNCN<NCNCN CN CN <N <N CN CN CN CN CN <N CN r- ax a pH •H rH pH pH rH B rH 8 CN CN <N CN CN CNCNCN<NCN<N<NCN<NCNCN CN CN CN CN CN rH CN CN CN <N CN <N

• 0 0 © T3 0 e 0 0 • CO 03 CO <0 CO Wl we CO CO fO CO O CO O CO CO CO CO CO COCOCOCOCOCOCOCOCOCOCO CO CO CO CO CO N 3 3 3 3 3 3

3 O •w CN 0 0 0 0 CJ O' O 0 CJ 0 0 0 0 > 00000 00000000000 0 0 0 0 0 <x 0 O 0 0 0 0

© 44 © 44 © -4 0 © © © © 8 © 8 <D<D<D<D<D <DQJ<D<D<DQJ<DQJ<D<D<D © © © QJ QJ QJ <D QJ <V <D d) cn cn cn a cn cn cn cn cn CO C/3 C/3 C/5 CO COCOCOCOCOCOCOCOCOCOCO in cn cn CO cn CO cn CO CO cn cn

©

CT> ©

a,

rinCTl in

«o

<n
at o Si at at a p e 6

10 tO

a

O at O' c c e a p co c P <0 at * *rl c at at

at O' •H XP ftH O' O' P c at o rH t0 c c

•h at P c P P at to to

0i e *• at at

C O' c Si si

0) 9 10 Si H3 at at •H CJ CJ p 3 jj s 

P C 9 P rH Si at o* c •• •• P CO p a at hh TJ pH pH « >1 to at co > C

0) .C <v c c co at at at jC •* <0 p O 01 T3 i c c P o at at U£H o ftH •H Z P o> e p at p at rH rH

at CO c -h

B *H i p

to "at

•H JJ at xts at P P o (a 6 O' o c Si at at rH P otj- 9 O CPC o 3 p p

•o

u at 5 +• CO

C to o O

B at at

at c -X <0 CO J3 -P at e e 3 Ed O Si T3 (0 >o U CP co o 10 to C A cj c c o o p p p

•H •• P (0 » <0 »p at % to to P as jQ •« o O' P P O' B 04 04 C i—)

O'

m Z M rH O-HH at o at rH a « o at -o p * % o T3 M P 1 p h at at at

at (0

H co

O CO

h at j= rH rH

u Ed 3 Cd

®

T ° p at Ed T3

C Cd 5 a

a < •<-i eu cr o OH o 04 B e e

E-ta

X (0 P* 3 P x at

X to a) < o* Et >\ 3 O 9 Eh C C Eh at X X K (V Os JS O O Bi O-H CP O' Ed B Ed

B

OS P P P4 (0

M CO c 04

a

Ed ft -H « e c <to to -z »Z

at <-! r» JJ 4J P P m HHO rH Si rH CS rH

B

O' rH ^ <TJ <*s

® rH “H rH CJ rH rH c 0 h

»—* Q) • O' P » c o • o 9 co n v».c O m c to co •• CO P co P

Si • JE EH

u • hH 3 • -C ft ft cj r» pi rH A H P t" P O’P' Oj r» s P'

B • % ft 10 (0 CD • to at • <0 • z • z

co >, CO

C c co

p cnu COB COB * =x • P at p \ • o' at • O' ft ft * •vr at p at Eh ft* at > ft* <0 * e •* s % P at p P o p o O o X o c si a U CO O to U p O P

at .x at °h » -H •Mb-* at mh to ata at mh at <4-s CO CO co CO co CO s zs z e s B o at o p p p

p e MH at mh 9 o rH O p at at at o MH p E at - a E p

tO

p to

B TJ o

at c at •• c B o atp

g rH rH 06

B CJ

to at at + at

a c B c O' Q a o' a o at in C B z c B p p •H* at to a •• 10 at l O' J= z f c 'OCX! at B MH «* c CJ Ed e C E CJ O' o at B

to

X 03 3 tO 3 c B

p

Si •• < C rH rH •• to at CJ rH Z tO o CO O rH J= at c O' Z B o - O + CJ O' •rH B c

•• + CO cm

a c B • to pH rH O at at z •• to at Si P co a co a O' Si at rH CJ

a> at at

x atx at CJ O' “*H c C B C Eh C Eh c at C mh •• fH •H Z •H -rl -P c »• to rC

pH rH Cd rH Ot rH 01 rH •ftH c Si 03 04 5 J3 rH o cj at (0 U p < P P P p p “rH ct u

a> at z at at at P P .. c o>

4J P B P c P C P at to at at (TS a> at at °ftH at -h at P 9 C »H M 6 e at E E E at 0« “rH Ot (0 <0 to O' 10 B to B to s at rH MH Qk

1-4 P c P P p

p

p to at (0 to to to c to C to p p fQ P rQ

04a sia toa toa to CO c g CJ p p a to o « o * ft 10 fctO - rH CJ o CN CM tO CO c f C ft B % at a <y rH rH C rH Q rH O rH a CM ft CO 00 • . to • U ft O ft z ft VC a

ro CO COB COB CO >4 •* ft • ft B ft ft ft B • rH %

P- rH pft <o M3P O' rH Sh **

nt j • B • + ft p • P • O • ft co a co a co O co O co p CO CO CO cn * e z • z • 2 . 3 . ft X c so • • e VO 8 ftp B f ft* B * q at ^ 0) at at z S S fH 1! o o o o O O JC O tj o a U “H O H O -cr at p at p at p at p at b at s at p ai •

co co co CO CO co co CO co

at CO SO CO O' o

O' CO ao CO 00 GO o* o

to CO co COm CO CO

Oi

B 0 rH s O' p z •o •o c 0 B B B at at

•rH at

p

B 1—

z T3 SiB

p rH z z E s c 0 ft p a 0 B a B O Cd B 10 Xb

CO E p z p E CO

B 0 M c p rH

B tO

B E E MH 0 T3 P c z 0 p at P X s O 0 at p at at at at a to P P

at » at rH E p

p at H3 P MH co- c ax

C

B to at

a at at 0 MH MH E toO ftHC rH HOf*O CO

x at •h ca

X •H T3 at

p tO at mh at rH Ed

a rH •rH

X

X Si 'O c

Eh > c rH MH at at c p at E X

H P CO

B

p at

m

B 2 B S E J3 to

p

C EHp at to e

TJ si at to to at

O c at at

b at c o' 3 at 0 Si E *• TJ in at E c c O' P s p a P B c O’XS P p •H * < e

4J O' tO

a MH at at 0 at at to atp •H E c C at at to at w O' E O' E -O Si B » at 0

•• "> O' to O' O'

a O' * c to

u c to cu

X MH

N c 'O

•ft* “ , "ftH Si at c c CJ c to P a) P 10 ftH 0 X c -5

® + at wi CJ O' to to to to Si to e si to P B 0

CO s c si s •• Si T3 CJ aa CJ

a at “ P 5 ftH ^ p z 9 p •• to CJ CJ rH CJ < •H 5 tO O S P mh

rH « a* Si z M Ot^ - at co ~ E p

O to

at

at

O Oft c CJ •• «• + OO •• rH > c in > O4 JL

pp fj

p T3 c > °* •H z rH rH MB to 0 to O “H f P ’O mh p at tH b ft 3 rH •ft + in at S3 at jQ rH • CQ P ca 9 rH 01 * rH rH 0) at at at c to CO c 10 rH " a <0 ftH P 3 c s at 0 AJ c c CPC •H ftH -rl at 5 at ho a rH 0 at

•rH P to I? ** CO at at •H ftH •ri at ftH rH

X

M rH

X 2 sz P ftH rH at

p at z <d c c rH rH rH P rH rH

a hh

h 0 ft P ftH » p c p X rH •rH *rl at P at -H p at to ^ to cm at 0 cm cn o at rH CO rH rH rH U P PEP at P rH at p 0 ^ p sz at at rH a) CJ 'D E to rH Ot * ai at at to at p 10 rH P 10 -rH ® p II P S3 Si T3

a> to c at ±» CO P P 4J

ppp

p at •H at at •H

p ^r| to 9 p II

u P O' at at ai at at to at E •O E •op" « C CO P < •H (0 *H lo .C p p e E E a E to at rH to O <d c O' a -rH at Ed O Eh 3 04 CO 04 at at <d to to to p E 10 P e > n> in x at 0 a < an B

1-1

a as E s u

p P X P to E CJ <0 E 3 co Et ex: 10

x » • 06 a» 0 u tO to <d to too n) a tH -ri a n at to a p p rH Eh X

06

U CN

C 'O

p O'pp 04

a

aa

p at at

a

a 11

x Ed • o o O4 <d to to p % •• p ft •• P O' ft p at at

<D N* *H < a

H

a

a

a ft ft at ft

b rH rH at rH rH 10 rH O' 06 » p

n CP rH 4J .. «> (d rH r—

in to in h* rH rH > rH

h at

H

a rH T3

C rH z c c • 04 00 O4 •• • • • • • • • • p JZ • C to •• rH >0

cd CO *H

CM * CN CM CO CO CO

C CO P CO co at co co at . tn T3 co 0 si O' • .C • 1-4 1 5 • • • ft B • 0 • at ft • .C • • rH CO Z at . u CJ CO CO (jicM CJ co 0 ‘ O r- r-~ r*• 1 rH i-. -p r-> p r-~ r~ p r- r- at • t"1 TJ r~ at 1 • C • aj f ftH • 1 • • • 8 • + • to • at ft B • ft B • rrj a c • ca •• ft* sc ^ H C ro <1> P m rH m ro a ro O4 ro O4 co c ro e co a CO <D CO rl CO rA >* at CO X p co 2 at • Q at 0 • at • • rH • z • z • at • to • z • AJ • M . ft • Eh B • ft ftH at 0 • 0 at p at > •* B H* + N* H* B •* p •* p ft* B •* at * a •* m •* 10 -* at p p > f rH J

T3 3 p at

a

X 10

H >4 z cr>p 9 P rH P O C cn-rH U rH 0 z 0 z 0 0 Cl 0 CJ Ed 0 a O O O (U O Eh O+OO at 0 to to O' P 0 0 at a> cd •p Q d) B <D at b at p at p at b at - at p 0)^3 0)b at •* at p at at a E -rl IQ at p S3 co a C/} co CO co co CO CO co CO co co co co co a co

in

<d r*

O' O'

<0 CN

04

in a\ VO 00

N* in in CO co cn CO m <7\ rH

in vo m cn

<n

r- rcn cn

435

Appendix

A,

Figure A3s

Add

label

"View

Volume

appropriately

to

upper

right

example
V >1 at

atke at we O' 3 0 B M JJ CO at JJ c m

<D at Qj 0 O at at T9 e at c 3 8 ke 0 0

C pH 0 0 at at ke at jj 10 a< m ai at c O' ke JJ 8 as 4-1 4-e u CN 0 at e at V.

rH cn at at ke 3 0) «. B ke to CtH B O • os 0 3

O' rH O at jz at b • c 09 >1 *H •H O' O 4H u as jj O • >1 rH 01 B

JJ 4H be JJ at co JJ • 8 4J to ke •H J3 ke •• rH *H • m *r| c at O

4J 3 a> 0 (0 09 >e CO eJ 09 >1 OS 8 4-1 ki 4-e JJ C 09 0 jj at at at JJ c at 4J cn cn c at at U c •H •H B O' •H ke at >1 •H •H • 0 w JJ ke >1

>i <0 B ke we CN CO JJ at rH ke ke 4J • X ke ID 01 ke O' JJ JJ 8 O' 04 c JJ -H JJ JJ c • 6 Of u at JJ O cn m at vo C C GO rH u X be c C u >S • OB O' C

4J CO U 44 CN at at as • at u at b at JJ • C CN - to u

• < at - rH • O' c b at r'- 0) •H >, 10 CN CO Oe B

CT> • os 0 O' O' • • c 0 0 O' O' O' 0 JJ JJ JJ rr at O' rH C • U O' c c • c to •H at c C CN c c C -H 09 • th at c 0

*—

•h c « m rH •H of •H • 0 -C 09 o' at •H • -H <0 8 U Jj B c 0 JJ O' •H CN T9 ) OOH CO j ® 3 0J> •H u c C ke s • 3 4J pH C O' H • •H c 3 •

0) O HN 3 C CO O >H B 0 O JJ at to at 0 • O CQ Cl C W rH >, JJ 10 O • 3 rH JJ -T O' ke 0) rH ‘» <^1 H <0 (0 •• E JZ 4-e rH >irH C *0* 0 at jj C JZ rH « C pH *H • C 4) O rH m m rH 44 JJ 0* •H 0 at H 4JH W • •H Of • k4 °H fe3 U rH OI •H o r- e • a JJ c O Os Cl 0 U 0 CO Q C6 O °H O • jj 0 0 3 jj O O

JJ 44 • -H e JJ X CU 44 • • OH 3 b as rH •• 4H > 4H Of • »H C e O' C 01 re 4h 10 c B (IH tl U U U • • 03 **• Cm at SnrH M >, C to >1 -H W ke >, 4-J o <u -«r > <u jj m at Q) • • at GO •a 8 jj JJ to 01 4J at 3 4J •H JJ JJ 4H 3 JJ at ke u •a £iO<0 Q 01 OS at mh -C >1 >4J= O »H c rH u CO ke C •C (0 •£ OVH 8 4J CO “H at JJ -H JZ 3 —

at JJ PH 4) HI 0* at JJ JJ JJ JJ •H * CO O 0 c at we 4J 4J •h 4J m at c jj 3 jj O > JJ 09 u • C « Oi C ke •H °H as m in CN IH -H Oe at 0 4JCOQMCC0 IO 3 **H < •H t> • -h u e e (0 T9 Jj JJ T3 r> JJ o» JJ • u T9 0 jj <0 0 o J3 WH U rH 1-9 4J <13 0

Eh 3 T9 • 4h 3 <U O jz at O C COH at • c • ke 8 tH X TJ W 'O 3 • at at >, Oe jj to no *H

«C O’ < H <U O' Eh u u o» < u u «c • e • at • S OcnftiH < to < 09 C • ke kg jj to E 09 -H < ke <2 4» O QH 44 B (0 • to • E Of 8 < O • 3 3 C ke at 0 JJ

OS u •• A 4-t >t >1 •• Oi •• JJ rH •• • ke JJ at b O % *Cfi * •• •« Jn-H >, O' O'-H ke Eh » 0 •• at U <o e w A me JJ co 09 C O CO 4J (0 C O rH m CQ (0 8 CQ O CO O' 09 10 JJ JJ *H °H 10 < co co co e V U>i03H >e-H 0 >1 0 at xi u Coe at 8 10 00 ViH O O O 4J O C 0 M ^ U O CQ 0 m

o» -H 09 -W 09 CU JJ JJ •H JJ •H g £*H»H E P"* H H u •H 8 O °H •H °H •H 1-9 C -U „Q <£ 4J u (Q*H< •H ke c 04 C CD -H c 04 -H CU OP >H CU 0 <3 Of VO 04 - 3 a»m Oe JJ CU* Oe ke Oe < ‘H C 3 3 CQ (0 rH Oe Oe 10 <0 OH 1IJ1H4JU 0 > O rH 09 O 04 rH rH oiinu O Cl O O X O JJ O 4hCi9 09 09 CrH OeO X O 04 A Eh <8 E h Q C Eh iH Eh U Eh c w • »H OV Eh at eh at Eh CO E< • ke at O 3 CO Eh at Eh o B U O W at JJ rH JJ 0 • Q • T9 * 0 •o CO 10 Q O' JC V O'-H T3 B T3

*4H OH 3 JJ 8 O 4-1 <0 <4H 01 <0 <JH O at • • at 44 CO 4-4 C <4H C 4H rH 4H at rH c ke ke \ C Q 4-e C rH 4-1 at O C 04-0 X c O -H O 4J U 0 at at JJ JZ rH • E O Cl O at O IH 0 to O -H 3 ke -H O O rH <0 O w GO O E O E 0 0 0 <0 0 -h a> c > *H at co at E CN We C 4J 0 0 3 3 3 to jj JJ Cl B XUHZH4J41 X 0 x c c X c we S JO *3 *T3 •H X S X at x at ke rH to JJ jj 'O 0 X X Of * X

ill 8 1 I 4) (0 at co a? -h a) at 0 3 -H rH 0 0 we oi <D 4-9 at rH 4) °*H 01 4J *H 0 IH at at 0 at at Of r-i O Of U

T3 rH C-O (0 'OfcU’auuic.fcZZtc 'O 0 -o 4) 'O -H 13 WO CUUQZZZOJ^'O-h^'DEh

C 0t M £ < Cl * e * 8 8 8 8 8 B £ 44 c M C fo C 8 C W B B B 8 8 8 8 8 C 8 C 8 m a M M w M M M M HH w M

at GO as O rH Cl

cn rH rH Cl CN Cl

to 04 in in in m m

at at k

jj O' 0 O at B at c •u 0 JJ B rH at c rH to 8 jj X* rH JZ O' 0 at JZ • B B r~ to •H c

•rH O u 00 B O' ke O to at 10 JJ GO r- co Pk g at 4J •H c JZ u — •• r- IH fk en S c rH > °H u

at at at fc* 05 O' 09 0 at <0 8 tJ 8 09 O' c M Z rH Z 0 0 B c as co •• >1

B to •rH s < B «s B B cn ke SO 3 » >1 4J 8 a rH cn B 8 C| at Cl at we ke >1

at 8 E at at CN jj •w 0 JJ 8 co 4J 4-f O' e •T3 at 0 at O' > 9 X 0 > rH C JJ at c •*H c 0 ke Of O' ke O' c 0 0 &3 as B O bj C H « 4J

to •rH u >1 C 4-e c to X 0 m O O ke 8 c

JZ JZ JZ 0 JJ to to JZ at at >ebe JJ u u a JJ 4H at JZ ke JZ u •c 4-> O' CO cn k ke a O

AS Of kl U to u CO O G Of c at 0 at at 4-f 44

•• ke k *Q -rH at •• at z (0 0 to rH JJ c c

at O' at JJ •• >1 re B -H JZ c JZ JZ 0 -H O' O' Of e to O' m e B B Hf jj r*J 0 Of U-H at e-9 c c 6

.—

•H ke 10 at 00 c O' r~ •H *

u co ke B 8 •H Of •a 1—

10 a 8 |H O r~ JJ u ee Of ee -H •H 3 rH r—i at a a IH -H IH g c Of >(4H >1> Q O O CN O u

3 jj c 4J jj 09 JJ 09 S w c JJ at JJ JJ rH •*r 8 rH c co jj O B U tH Z to z 0 Of •H ke -H CO k rH e as rH Of •H ke co at Of < O < 0 c 0 > > 3 CO B O • r- O 8 4-f JJ •rH to JZ JZ CQ c B H B B 0 8 •H at -h at at ke 4-e • rH 44 rH H c 4-e rH ajj c •rH rH •H JJ O' JJ -H jj at 9 CN C 0 10 M at xi at at JJ 10 to to > 3 -Q at 4J 9 Of 8 •H 0 T3 * k ke O at C 3 c c at to 0 •H a •H B J3 E j= •H 9 .C 9 as &4 — at in vo O' JJ •• O' h a •H •H -u JJ rH O O •H 3 jj 4J >1 4J 9 ke a Q to c Of 10 r—

1—

ke rH at 0 rH O X O O ke Z c 4J 9 rH < •rH ke -rH c a at at rH c O CO at CO JJ JJ T9 u •H 'O c • e

Eh 3 c C <0 B •H k O' k T9 k at c 44 (0 T9 co JJ C T9 4J O 9 0

O* 0 O a rH at CO c co ke co O 2 < c < B «C kl < c c < ® u « at •rH •rH 0 ke at <0 at O at O H JJ at 0 u 4J 4-f *44 OS ke JJ JJ JJ JJ 4J O O JZ 0 at 0 ee k 44 k kJ3 k HJ ee ee -H C u O O co CQ c c u c ke c cc CO co at CO O' CO JJ a 44 4J CO C •H 8

at at at 10 B <d O' at at at 09 0 8 u rH O H 0 >0 0 -4 c O -H O >1

O' 09 8 09 rH Ot rH IH ke >0 ke T3 ke < •H •H •H •H at •H Oe H c **H •h 4-e CU -u c c JZ at c at C at 8 eJ am a be as a 0U*rC O a at *r< to * 0 k k JJ «e •• 4-e fO 4-e to 4-e x* be 0 <N 0 0 O JJ 0 44 04 0 Q -LJ 4J JZ Q •r* a u Dm 0 at at at r- Eh • Eh at EH at EH C Eh Of Eh u c 0 4-1 c OS B OS B CCS g

• O B c 0 O 4J ke <v u

X O X X -rH X X O' CO os >1 44 • 4-e C rH 4-1 -H B 4-1 be 44 O 4-e O c

-rH Of •r! •rH •H 44M 44 r- 44 0 IH 0 rH O at 00 OeJ Jt O O U Of O *H c

•o CQ T9 TJ O 'O T9 O H O' 0 M O 0 03 O ki CN JZ at O c 0 0 Of c 8 C C JJ c C 09 r~ 09 B CQ X X at k x » cn x c X rH c X u u 4J

at at at c Of at JJ Z O' JJ Z JJ CQ at e at 4-4 O at c -h at -h at O 0 at b m Of a O a a--H 04 a CO < rH CO < to 0 O T9 >iT9 at o' T9 at at T3 eJ TJ CJ CJ T9 pH a 4J a ai CU a •H B B •H B H JJ rH c 09 c OS B c a :s C B c 8 8 G Of < < < < < eJ eJ eJ O M M tH IH M IH a

at ** so as rH in r* Hi in in VO

O' GO GO av O rH rH rH rH

10 aHi in m m in m
C «• 10 o ffl -H •H C

*J O OH n -H >-H 4) *) O

rH 0.^

0 o'- o H c

8 8 ° o°«

fli ^ H

to

10 r* 3 o

8 44 JS * ®

1 a ” ^ rH 44

a* a> rH *0 '

C (fl 8 fl> o

- -G o 4J J) * e

s

>o g ®

i. to

<U e

14 II U

O O -H C <8 4J«|ft C *)

II (0 >4 e c ti

ai m

« ai s

O, * “a ai r tPO o

-« 5

(fl OH 8

3 2

-a w ~

c“S?

S"3 «

Tl ^ e

c

c ° S -h -w U <u W 4J

I TJ I O G 43 e a o

B

00 O ®OH

U I l-i 8 co o

3

0 «*J

4-1 1-4 01 3 C

10 O'

01 ’H | i ^

64 3

3 — 0

44 % <0 •«

a> j< ^ S e 3 *

®

<8 4J Jj 3 S 2

CU «j

10 °

i! c >M r-l •H G r1 n

4J >1

;-p c

to

01

1-4 3

o>

433

O]

in

(N

0

01 M

> >

o

* ^ (0 C S 8

8*H o

0 4-1 to **.0

01 c c

> 8 18 <8 6

JS '

(0 to

to 0) g <D -H G

2 *3

O' *4 5 •*4 C C won 43 -H 3 <*4 *1 MOO

•HJfl

C

•H 'O <u •g ® M

®rH D ° 04 O'

01 o£

3

®'-g

O' °*C0 H «

-Q “ M

3 rH o " *

•8 o "JJ rH Z

>*-w

•fl t) 01 _ 8 43

•w /-> • 04 2 >1 •H°4l

O -H

0) 01 *4 afl c

10 44 8

« ®

e 5*

O 4-1 (0 c H

H «

to o g -2°*°

ip

&S*

o«*4 •* c o i

o °

o in

w* c • m CN

rHB 4-i O W *rt to a» *>

4J O

a 0 ai *48 w

>1*0 8 oi

*4 -H 2 o* < o

*4 0

<TJ (i| 3-° « O

•2*

<-> >,

o'- * ° 01 10 >4 01 *4 M 0) * 18 44 •s-0

a

k4

18 °*

*8 W i—

3ii-H® «<8 ?<*4 W

C . 41 8

’H r

*4 O >

o 01 °

0) 0*0 « to o

•H <8 >,*

<S

to cl

0,5 o a» M-4 M«°

S o 0) 5flc

o

SO O c _ w **

. — i01 O’_

03 3 -rt 0) 2**0 U ,H *4 3 <*4 O

O'-O O •woo

1*4 M 18

C 01 01 O C *4 •H O 3

44 O' -W to -H C *8 4*4 M

01 C J=

*4 01 4J „ <U 4*4 ^2 ° »t I " n

0) A)

*43 O'

O' c

*H ‘H

64 >

<8

. J= C

0 S •w O

1*4 a> >ix: o x: 4J 4-1 EH -w a,

to *1 01 *J . c Q

tO >1 ®> •W 4J f

in -w C 4-1 o c o 0) 106u c

.5 w 01

w >1 0)

- M a o' 2J w

3 'W O' C 01

•-t o , ^

ai *4-1

oi 5

0

"-*8

E"f- 1X3 4J 3 O

M C

W 1*1 2 sc 3M

>1

01 IQ >

C 1*4 O O

U *4 0) 0 18 J3

&* rH EH

• S' • ® ® O

® 18 O c a, ®8h ° 3 O

- O

w 0

2

c to C-H *1-W

to >i 0) Its C

*4 e -w 3

O' >1 >4 •W 4-S 4J

1*4 -W -W

J3 4-> 4J 3 C C

M 0) 0>

to O 0) *40

•S-S « 2

3 5

.2 0

>1 ^

4J (Q °H (jj W*4

fl ®

41 u

4-1 c to O 3

°H rH

4J rH •H *H c

•w

<*4 rH

0) I Q «S

to 4J

,Oh*c 8

C <u 4J IQ 10 ki c 4-1 "W Q.

01 (0 X3 *4 C 4J 0) Ch a

4J O o C

•W <d ** "H

S

°1

'

•H -w <0*5. H *w 1*4 C = ®ao.5 Q 3 04 3 M to “

® 0) -

‘Ha,**'5 3 ^ *4 . O'

01 01 O rH C 8

8 O

44 8

8

C 8

M 43

44 T3C *o 8 C

8

C

o c

H O

*4 -W w 44 C 8

•H O

44 O

8 <w a

SSI 8 *

*4 >* Si*

•§-

M

8 8 rH

43 43 8

44 44 T3O

8 *« B

*4 O

8 „ O

y 04 *, o“e H 5-W

cu O4 w on C °

8 §

•c^J '2

*4 10 >1 -H ®

44 C -g •W -W 2

44 1*4 g

C 8

-H 8 >0

>1 8 8 ^

G *i t

2 o «

8 44 c e

l_l -W gO

e

>* C 44 8 <*) B

jj 8 C

8 « ® %

-G g rH

58 S^-e 0) e 4J e

-So* G >11*4 8

8 1 3"*8fl fl m-

>*44

Z 8

8 8

43

-g

44 fl* o C o • 8 >h

w 44 .

g-H C

C «*4 a c 8

*4 44 3

8 -W O'

43 c -w

4J *W 1*4 <*4 X3 3 8 3

•W a M

M .

E 8

8

3 8

S.;S S

8 > 3 43 Q 44 M *4

43 8 J C 8

O 44 o O 43 8 -W C -H 44

63 44

- -W 1*4 .. >1 8 c O

8 -0 “H -W J 44 *4 O c >,8 O

rH O 44 Q 44 rH 04-W O

O 3 44 8 8

t*4 c *4 > 8 -S * O.C

•JUs®

8 8 O 43 44 -H »h 8 3 fl 8 63 M _4 8 CU m

8 O . 8 c

8 u-C n, 8 8 O fl *4 ° hH 44 44 O

OH C o ow

C 44 O -w •W C

44 -H o **4 8 8

rH T3 rHO 8

O 43

44 >1

44 C

•H -W

44C t3 8 8

44 8 fl F u

E4 o

— 88 8 -W J3 O ^

^

2 *4 F G C W 8 -rt m

8 8 .h H O u 8 C Q 0 8

°

t0 44 A, “ 43 8 C 7j

43 H **

44 44 ® 3

O

® c 8

® °. > 8 8

8

O T3C

43-* A **»

g 8 X

© Q..H G C-W 8 *4 •W *W 4J jj “A 10 C 8 «JJ 8 rH o G 08 h

8

C 44 O' 5 8 8 >H c

g, *, M C -w 83 ^ ^

G

o 3o 2 C

Qis«

8 H

8 >1 2

-W ^8

8 (*4

8 8 > 8 O' Q* 8 *4 C

8 — 3 -W 8 >, W O' W , •W *4 © -w u 8

rH -W 44 1*4 8 o a 44 o 43 1*4 8

CU C 8 3 8 CU 8 8 UH M *4 8

8 O'

•rH *0 —

o' oh e 8

-O S«k5^

O 8 U c ^

C> G 44 -H &

*t 44 8 43 C

CU g 44 8

a

'*h 43 8 .w o, * &h

44 G . • >|-W ^ >< ^

*1 C jj 44

UJ 'W «W 8 "rH 3 44 1*4 O 44 43 C 8 O C

E* 8 UH 41

C w 0

•W "H5

44 OH -w 8

c Q

1*1 8

8 *4 D 3

O' 8 °w

(H OH 3 43

O' 3

-rt M

OH

43 8

3 43 M 44

44 3

X 01 8 01 »H “Is

•W 8 8

4J 43 O

C 44 8

^04 8

8 0

0 - C 8 ^

«* 8 44 8 "

8 *0 *• CW *4 3

8 8

8 44 8

*1 8 *4 3 E „

O' 8 <0 OH 8 43

43 CU Eh 3M 8 * 43 ’O 8 44 8

43 rH

*1 CH

•h CU

OH cu O "O 8

8

8 44 —

0 8 8

8 O *h CU O 8 8 rH —

8 8 C

43 O -W

44 C

8 *4 *44 8

j7 to 43 J-rH z 8 "

>H 8

-* 3 8

is-z •H 1*4 *"

44 43 t; C 3 ; 8 M G

0» ®T>

2 0H «

to M

G *4 M 0 8

44 43 8 o 44

*4 8

3 > 8

O' 8

•H C 44 OH O 8

43 -w o

3 4) O

W 8 rH 8 g 2 43 5

" H

44 S-G

44 ^

0*0-3

C m

8 8."

O ^ « X n.

8 C • rH

*j -W T3 8

3 ® *0 0»*0 rH o

•W 8 >H g

OH 44 CU n 8 CU w

3 O fl 8

M . 8

1

>1 «

.ti o

A* 8

8 4) 43 8

44 HQ O 44 t

C c C 8

8 O 8 >

C C O

O 8 44 •W 43

44 3 >1 •w 44 c >rH. "H rH

OH 44 £G

8 O a 8

X

8 8

8

£

0H 44 8

8 O

01 C _

« m 8 C jj G

u 8 m

o W5J5

8 c C >7 »h 8

O * 3 o

r4 X O'

*4 -W 8

W 8 OH 44 C 43 43 8

•W 44 3 8

04 M _ 8 * r n >141 O U rH .C .rt

a. rH 44 44 ® 8 m

“g C OH rH

44 • W © 8

Bs* C C ® 8 rH *4* u 8 g

CU

Q. “H 8 tH

4«J W

e 2 8

0

e u is* • si * °rt -rt rH

OH 1*4 44 8 8 C

*a *o 8

0*4 u

8

c a,*2 88 " 43

• . r 11 o

8 C

flu O

8 rH

8

E 44 8 8

*4 43 8 *4 CU

. 8

*0 UH 8 *4 O 8 43 O

s a 44 z

8 ,

8 "tr S>2 C

!S “ >. 3 c 43 W O o rH *4 8 44 •H 13

Oh C 8

O -H 44 OH C u *a o . 2 cu 8

® 8 44 cu 8 8

8 O -H C

44 -rt C >1*0 o 8 *4 *4 W > rH O >C3 ij *rt *4 43 g 8 8 8 in

SgSS 8 “ CH *0 8 8 8 ^ 44 O

8 8 ‘H r-i C “I *4^” ^

o'Js"

44 38 44 O' *H

|j H H

O AH A* *43 "H

>1 3

8 44 w jj O -H o

8 44 8 ‘H

CU C 43 43

e?

c=4

8

C

•rt *3 8

C »

rt *4 *3 O

rH

*> o

c o

CO B 8

Q> 00 CU »

•H p~ 8

U CN te rH

4J - 8 43 e 8 rt W

CN VO 43 8

CN CO -w *w

a***1 • 8 >

C 0 • rt •H 0 • > 8 O » « O' >* > 8 O >(J> *4 8 8

3

** rH *4 <N -rt J -rt C rH -H • > 8 >

•rt O 4J • *H *H 1

*4 0H C • 44 >

c 63 >, 8 B O

0 8 44 -H *J 0 *a 43 8 -w O 8

8 *4 *4 > O O' B B

*4 8 -H 8 C >1 >1 < -rt -a rH 44 8 8 44 *4

Eh 3 •O CU 8 < 43 -rt -W < O' < E -rt O > > 2 8 8 O CU -rt -rt 03 w •• EH O 3 •• *4 *4

6] 8 8 0 8 8 8

8 O >1 8 *4 O -rt -w

O' •rt 8 < (J -rt O O

c CU rH CU O O

8 O CU 8 *0 O 8 8

43 Eh 8 -O 8 Eh 8 8 O •HOW < <

OH Q Z 8 OH O 8 0 44 *4

14 44 u 43 43 X X X O X O' O' 8 8 8 C 8 -n -rt *0 t* &H D T3 8 8

C B C 2 %

8 m

O' CN 8 in

CU
M2*3Xa

o.z s3I3

ON

cnI wM

(S4

DoOH co

CO 4J

CQ

C *- O W

*H (0 4J 3

<0 tH U rH

CO3 cC

»-»

w • H «H <U t4 J U

<U

u a©

03 CO rH Do Do

0) CM

05

O § N

<=H

U

09

41 a

(0 XI « c 3 0)

1-1 T3

(0 c > « £

a» £ *o 2

«3 a*‘H

»W 4J •H « W -pH UJ <W « « ft ° a* J3 Xs S3

*"» XI »rH as m

•O 4H (3 B © > 3

(0 Xl

as c 3 <u

i-t <n 5 B > as . °* e ® £ *o

ai c 14 -5

as

ti_> «M ^

hH to 15 <0 ^ as «w <2 © ®2

fcs X* 43

as u» J3 4h <3 S O > aZ

xi XI XI xs as HJ 13 XI 13 to CO CO CO "B C XI C xt

l>l

U <3 4J at >3 at <3

•pH hH IH >o -o no 13 44 hH Xl c c

as oh ^ 01B at sz as xi pH (H (is pH OH Q*Xl Qt (0

as

a as .a as as i at <3 JZ 13 j= (3 5 * rH •o .* •O rH

Xl *H jj “H at xi -u

tH **

u

u - t3

C jz as xs at

ilj t3 (3

B hH -pH XI J= to JZ

O > 4-t > o > XS

U

O 1 XIm XI

O <3 Q. •ft rH

+* iJ 4J > XI XI

at

a asb o$ s ii * S3 as <3 as

m

a as 5

at 3 0) 'T XI 4J JG JZ

rH 3 o C 13 xt as xl 41

(3 S r*

C 2 e at T3 rH rH > as <® as <3 © X> an X) an £> a* > Os > Q» at 6 x> O (3 XI o m xs ® as OS at co *H C •pH C

ii 13 it 'O 3 aa at ih <ph OS

M -pH 10 g ** C m B rH OS “*H 3 <3 O 3 (3 O « -H ® °pH - T3 an rH > 0* rH > Qt •H >3 (3 <8 <3 <3 Cm H 3 pH > > >

HVALIj
Research Information Center

National Bureau of Standards

Gaithersburg, Maryland 20899

NBSIR 86-3359

INITIAL GRAPHICS EXCHANGE

SPECIFICATION (IGES), VERSION 3.0

mi

Brad Smith

Joan Wellington

U.S. DEPARTMENT OF COMMERCE

National Bureau of Standards

National Engineering Laboratory

Center for Manufacturing Engineering

Automated Production Technology Division

Gaithersburg, MD 20899

April 1986

U.S. DEPARTMENT OF COMMERCE, Malcolm Baldrige, Secretary

NATIONAL BUREAU OF STANDARDS, Ernest Ambler. Director

Special recognition is accorded to the following officers of the IGES

Organization who have contributed heavily to both the technical content

and the editorial review of this document.

Jeff Altemueller McDonnell Douglas AIS Co.

Raymond E

Barker Caterpillar Tractor Co.

William G. Beazley W. G. Beazley & Assoc.

Kalman Brauner The Boeing Commercial Airplane Co.

William C. Burkett McDonnell Aircraft Co.

Noel Christensen Allied Bendix Aerospace

Edward Clapp IBM Corporation

Robert Colsher IGES Data Analysis Corp

Spencer DePauw Caterpillar Tractor Co.

Jim Fleming Cummins Engine Co. Inc.

William B. Gruttke McDonnell Douglas AIS Co.

Dennette A. Harrod Jr Applicon Corporation

Robert Ivey Westinghouse Electric Corp.

J.C. Kelly Sandia National Laboratories

Philip Kennicott General Electric Co.

Linda Martino IBM Corporation

Larry 0 ’ Connell Sandia National Laboratories

Curtis H. Parks General Dynamics Corp.

Kent Reed National Bureau of Standards

Patrick W. Rourke Newport News Shipbuilding

Douglas Schenck McDonnell Douglas

Fred Stahl IBM Corporation

iii

THE FOLLOWING COMMITTEE MEMBERS HAVE CONTRIBUTED TO THIS DOCUMENT:

Joseph Aeb i scher Martin Marietta Data Systems

Jeff A1 temuel 1 er McDonnell Douglas AIS Co

Bi 1

1

Ander son General Dynamics Corp.

Robert E Anderson NAVA I R Engineering Support Office

Col i n Ash 1 ey PAFEC Ltd

Paul Atallah Electronic Data Systems Corp.

Dave Bar ker Hercules Aerospace

Raymond E. Bar ker Caterpillar Tractor Co.

Willi am G. Beaz 1 ey W = G. Beaz 1 ey & Assoc.

Ronal

d

Bel cher McDonnell Douglas Automation Co.

Peter Benj ami

n

Lockheed Missiles And Space Co.

Ted Berenyi Deere and Company

Dieter W a Bergman I P C

Kevin Bl ackwel

1

Lawrence Livermore National Laboratory

Donald L . Blank Sperry Information Systems

Sandra Bowen Electronic Data Systems

James A . Br adf or

d

Allied Bendix Aerospace

Nor man Br ai nar

d

Electronic Data Systems

Kal man Brauner The Boeing Commercial Airplane Co.

Raymond A* Br.engs Naval Ship R & D Center

Davi d Briggs The Boeing Commercial Airplane Co.

Stan Br i ggs Naval Air Rework Facility

Ronald Bryant Xerox Corporation

Willi am C, Bur kett McDonnell Aircraft Co.

Ri char

d

Butler Comput er v i si on Cor p

.

Br ad 1 ey K. Cal 1 PDA Engineering

Gerald E n Campbel

1

Comput ervi si on Corp.

James Carter ry NAVFAC

Lt Robert Carringer US Air Force I CAM Office

Dr. Nien —HUel Chao AT&T Bell Laboratories

Ken Chr i stem sen Ford Mot or Comp an y

Noel Chr i stensen Allied Bendix Aerospace

A1 Ci nqu.e M. Rosenblatt & Son

Edwar

d

Cl app IBM Corp.

A 1 an L . Clark Ford Motor Co.

Margaret Cline Lockheed Georgia

Robert Cl i nes Martin Marietta Aerospace

Ri chard Cochran F'r a1 1 & Wh i t n ey

Char 1 es E. Cockrel 1 NASA Langley Research Center

Robert Col sher IGES Data Analysis Corp.

Ri char

d

Costab i 1 e Xerox Corporation

Gary A. Cox LTV Aerospace and Defense Company

Robert M . Curry TRW Electronics & Defense

Kar 1 i

s

Danker

s

TRW Electronics & Defense

Paul H. Davi s Pratt & Whitney UTC

Anthony James Day Sikorsky Aircraft UTC

Mar k Demeranvi lie Sperry Defense Products Group

Spencer DePauw Caterpillar Tractor Co.

Kar en Deutsch CADAM Inc

Ri char

d

N. Di Fronz o Metagraphics Inc.

Ral ph Di sa Pratt & Whitney

George Donnel 1 an Honeywell Electro-Optics Div.

v
Ron Downer Hughes Aircraft Co. EDSG

Alan E. Dragoo McDonnell Douglas MIS Co

Marc W. Dur nin Lockheed-Georgi a Company

Colin R« Earl Automation Technology Products

Robert J. Easterday Martin Marietta Energy Systems

Ri char

d

Eppes Jr US Army Missile Command

Nick Fki ar as Tektronix Inc.

Jim FI emi ng Cummins Engine Co. Inc.

Henry H. Fong PDA Engineering

Danny Forth man Br uning CAD

Peter Fossel man Douglas Aircra-ft

Lei and H. Frayseth Bechtel Petroleum

Willi am R- Freeman Allied Bendix Aerospace

Ri char

d

Fuhr The Boeing Commercial Airplane Co.

Roger Gal e D. Appleton Co.

Walter F. Gei singer Construction Spec i -f i cat i ons Institute

Willi am Gerrei

n

General Electric Co.

Albert. J, Gi bbons Westinghouse Electric Corp.

M i t c h ell Gi 1 ber

t

Grumman Aerospace Corp.

Burton Gi sc h ner General Dynamics - Electric Boat D:i. v. Rai ner Glatz University of Karlsruhe

Scott A. Gordon NASA Goddard Elpace Flight Center

William Hu Gray Martin Marietta Energy Systems

Willi am B. Grutt ke McDonnell Douiglas AIS Co.

John Hardt Dana Corp.

C. Scott Harr i

s

Hughes Aircraft Co

Dennette A« Harrod Jr Appl i con

Mi chael Hast! ngs Control Data Corporation

Don Hemmel gar

n

Inter n at i on a 1 Tech neGr oup I n c: Edward C» Hong Electronic. Data Systems

William A„ Hussong Honeywell Inc. Avionics Division

Ri chard I s 1 er Sand i a National Laboratories

Robert Ivey Westinghouse Electric Corp.

Dwight L. Jaeger Los Alamos National Laboratory

Scott E. Jorgenson Control Data Corporation

Anthony Joyce Naval Facilities Engineering Command

Esf an Kamvar AT & T Bell Laboratories

Thomas Keane The Boeing Commercial Airplane Co.

J.C. Kel 1 y Sandia National Laboratories

Debb i

e

Kengott AutoTrol Technology Corp.

Phi lip Kenni cott General Electric Co.

Stephen T. Kerti

s

Naval Weapons Center

Gabor Ki 55 Bell Communications Research

Karen L. Kontry Electronic Data Systems Corporation

Sudhi

r

Kshi rsagar SDRC

Stanley J. Kukla General Dynamics

M„ J. Kut kus Hughes Aircraft Co;

Harr y Ladd DuPont

J ohn Lamoureux I IT Research Institute

Debor ah LaF'ay Westinghouse Electric Corp.

Lanse Mu Leach US Military Academy

Kai man Lee Naval Facilities Engineering Command

Bruce Lepi sto Department of Defense

vi
Olga Li chten IBM Corp.

Mi chael Li ewald Hughes Aircaft Co.

Vincent Lin Automation Technology Products

Robert Li pman Naval Ship R ?< D Center

Lincoln Little Cummins Engine Co. Inc.

Julie Long Electronic Data Systems

Bi 1

1

Loye Inter connics

Robert Mac Latch i

e

P 1 an Print Comp an y

Spencer Mag 1 eby General Dynamics Corp.

Bi 1

1

Mar ks Hughes Aircraft Co

Linda Marti no IBM Corp.

Steven Mastrangel

o

Micro Control Systems Inc.

Ralph J. Mayer Adra Systems, Inc.

F;aphael McBai

n

General Dynamics Corp.

Mar i e McFar 1 and Hughes Aircraft Co.

Stanl ey Me Mi 1 1 en Gerber Systems Technology Inc.

H. W. Guy Meyer Wisconsin Dept of Transportation

Thurber J. Moffett Nor t hr up

Charles B. Mor r i 1

1

IBM Corp.

R. G. Morrison Jr McDonnell Aircraft Co.

Joseph A. Mudd Bechtel Petroleum Inc.

Roger Nagel Lehigh University

Paul A. Nel son Hughes Aircraft Co.

Davi d Nor ling Boeing Computer Services

Fred J. Norton Lawrence Livermore National Laboratory

Prof. Horst Nowac k

i

Technical University Berlin

Larry D’ Conn el 1 Sandia National Laboratories

W. Rob Oakes Los Alamos National Laboratory

Jeffrey Otten General Electric Co

Connie F'anz i ca General Motors BQC Hqts

Geoffrey H. Parker Intergraph Corp.

Curtis H. Par ks General Dynamics Corp.

K1 au.s F'asemann Vol kswagenwerg AG

Alan Pel tz man Software Consultant

Steve Peters Pi erce, Goodwi n , A1 ex ander

Freda Phelps Lawrence Livermore National Laboratory

Jon Pi ttman HQK Computer Services Corp.

VI ad i mi

r

F'ochop AutoDesk Inc.

Tim Prohaska Allied Bendix Aerospace

Lloyd F'urves NASA Goddard Space Flight Center

Kent F^eed National Bureau of Standards

Gaylen R„ Ri naudot National Bureau of Standards

F'h i 1 1 i p Rosol Martin Marietta Data Systems

Patrick W. Rou.r k e Newport News Shipbuilding

Walter J. Rygi el Ford Motor Co.

Randy Schmi

d

Hughes Aircraft Co EDSG

Dirk Schroeter Martin Marietta Orlando Aerospace

Arnol

d

Shak Grumman Data Systems

Jer r y Shaver Gerber Systems Technology

Chi a Hui Shih SDRC

Mar i e Skutch Westinghouse Electric Corp.

Br adf or

d

Smi th National Bureau, of Standards

Keith M. Smi th Summa Technologies Inc.

vii
•7 i rn Snyder Martin Marietta Energy Systems

Mi chael V. Bp i nosa Computervi si on Corp.

Fred Stahl IBM Corp.

Jef -frey Star University of California

John Stedman Mentor Graphics CorpEdward T u St i ckl

e

Martin Marietta Energy Systems

Char 1 es L. Stoddar

d

Pr at t & Wh i. t n ey

Randy Ter ad

a

CADAM Inc.

J u 3. i a Terry Martin Marietta Energy Systems

Davi d Thei 1 en Allied Bendix Aerospace

Mark A. Thiel McDonnell Douglas Automation Co,

Alistair Thompson Cambridge Interactive Systems LtdC « B . "Bill” Thompson Southern Company Services Inc

Paul Thompson Control Data

Vine e E . Thompson Burns S< McDonnell Engineering Co

Di etmar Tr i ppner BMW

James Tul enko McDermott, Inc.

James A. T urner Un i ver s i t y of Michigan

Robert J n Ventura Martin Marietta Aerospace

Earl F'„ Weaver Ballistics Research Laboratory

Donald Wee h si er The MITRE Corporation

Jerry A. Wei ss McDonnell Aircraft Co.

Uwe Wei ssf 1 og IBM Germany Dept 2081

Robert Whi te Computer vi si on Corp.

George Wh i tehurst NASA Langley Research Center

Willi am Whi teman Enterprise Systems Design Inc.

Gar y Wh i 1

1

Intergraph Corp.

Peter Wi 1 son General Electric Co

Robert M n Wi 1 son Martin Marietta Energy Systems

Ri chard c. Wi rrf rey Digital Equipment Corp.

Edward R „ Wi t ten berg Ford Motor Co.

Deborah A. Wr i ght United Techno 1 ogi es~Si k or sky Aircraft

Sheree Yang Ford Aerospace & Communications Co

Siu Fun Yu Hewl ett-F’ackard Co.

John Zimmerman Allied Bendix Aerospace

viii
IGES Version 3.0

FOREWORD

Version 3.0 of the Initial Graphics Exchange Specification greatly improves upon earlier

publications of IGES Version 1.0 in 1980, ANSI Y14.26M in 1981, and IGES Version 2.0 in

1983 by extending and refining the specification in many areas. The refinements, which

improve on the clarity and precision of the specification, are in many cases the result of

considerable implementation experience gained with IGES across a large number of

systems. The many technical extensions in this document reflect a desire to expand the

specification’s capability to communicate a wider range of product data developed and

used by computer aided design and manufacturing systems. They are the result of two and one half years of technical work and were approved by IGES committee members in

February 1985.

Despite the many changes to the earlier work, IGES Version 3.0 remains for all practical

purposes upwards compatible with Version 2.0. This means that a translator fully

conforming to Version 3.0 can correctly interpret IGES files written in accordance with

prior versions of IGES. Minor technical changes do exist which do violate this objective or which would have violated this objective had any earlier translator been written to put out

some of the more complex entity structures of Version 2.0. One example of a non- upwards compatible change is in the specification of connect points where the earlier

approach was shown to be logically incorrect. Other changes introduced into Version 3.0

make obsolete the older entities, but it is believed that these older entities had never been implemented.

Considerable clarifications have been made in the 3.0 document in areas of the View and

Drawing entities, in the Global parameters including default values, in the Units flag, in

the Transformation Matrix pointer, in the Leader entity and in the Parametric Spline

Curve and Surface entities.

New entity capability has been added in the geometry area for Offset Curves, Offset

Surfaces and Curves on a Parametric Surface. A Trimmed Surface entity allows the

definition of a surface boundary.

In the annotation area new capability exists for representing a larger range of annotation

style of the base value and the tolerance limits. Additionally, a more compact definition

for crosshatching is given.

Version 3.0 introduces greatly enhanced capability for user defined MACRO'S essential for

standard part libraries. By adding Labels, Branching and Calling arguments to the

previous MACRO capability, the Version 3.0 MACRO is able to represent parametrized

IGES constructs that are user defined. Coupled with another new extension for External

File Reference, users will be able to implement large standard libraries of symbols or components.

Finally, Version 3.0 introduces a means of reducing IGES file size to one third of its

previous size. Called the Compressed ASCII Format, the optional technique addresses

storage size and telecommunications costs. Utility programs are included in an Appendix

for two way conversion to the Compressed IGES physical file format.

IX

TABLE OF CONTENTS

FOREWORD ix

List of Figures XV

List of Tables xviii

1 General 1

1.1 Purpose 1 1.2 Field of Application 1 1.3 Concepts of Product Definition 2

1.4 Concepts of the File Structure 4

1.3 Concepts of the Information Structures for Wire-Frame

Model Descriptions 5

1.3.1 Property Entity 6

1.3.2 Associativity Entities 6

1.5.3 View Entity 6

1.5.4 Drawing Entity 6

1.5.5 Transformation Matrix Entity 7

1.5.6 MACRO Entities 7

1.5.7 Implementor Defined Entities 7

1.6 Appendices 8

2 Data Form 9

2.1 General 9

2.2 ASCII Form

2.2.1 Sequence Numbers 9

2.2.2 Constants 10

2.2.3 Rules for Forming and Interpreting Free

Formatted Data 14

2.2.4 File Structure 16

2.3 Compressed ASCII Form 61

2.3.1 File Structure 61

2.4 Binary Form 63

2.4.1 Constants 63

2.4.2 File Structure 69

2.3 Specific File Structures 85

2.5.1 Subfigures 85

2.5.2 Connectivity 88

XI
2.5.3 MACROS 90

2.5.4 External Reference Linkage 90

2.5.5. Drawings and Views 93

2.5.6 Finite Element Modeling 95

2.5.7 Multiple Transformation Entities 98

3 Geometry 103

3.1 General 103

3.1.1 Coordinate Systems 103

3.1.2 Directionality 106

3.1.3 Geometric Entities 107

3.2 Circular Arc Entity 108

3.3 Composite Curve Entity 111

3.4 Conic Arc Entity 116

3.5 Copious Data Entity 122

3.6 Plane Entity 126

3.7 Line Entity 130

3.8 Parametric Spline Curve Entity 132

3.9 Parametric Spline Surface Entity 138

3.10 Point Entity 144

3.11 Ruled Surface Entity 146

3.12 Surface of Revolution Entity 151

3.13 Tabulated Cylinder Entity 155

3.14 Transformation Matrix Entity 158

3.15 Flash Entity 167

3.16 Rational B-Spline Curve Entity 169

3.17 Rational B-Spline Surface Entity 172

3.18 Offset Curve Entity 176

3.19 Connect Point Entity 179

3.20 Node Entity 181

3.21 Finite Element Entity 184

3.22 Nodal Displacement and Rotation Entity 192

3.23 Offset Surface Entity 195

3.24 Curve On A Parametric Surface Entity 198

3.25 Trimmed (Parametric) Surface Entity 201

4 Non-Geometry 205

4.1 General 205

4.2 Annotation Entities 206

4.2.1 Entity Type/Type Number 206

4.2.2 Construction 206

4.2.3 Definition Space 207

4.2.4 Angular Dimension Entity 209

4.2.5 Centerline Entity 213

4.2.6 Diameter Dimension Entity 215

4.2.7 Flag Note Entity 217

4.2.8 General Label Entity 221

xii
4.2.9 General Note Entity 223

4.2.10 Leader (Arrow) Entity 238

4.2.11 Linear Dimension Entity 243

4.2.12 Ordinate Dimension Entity 245

4.2.13 Point Dimension Entity 247

4.2.14 Radius Dimension Entity 249

4.2.15 Section Entity 251

4.2.16 General Symbol Entity 254

4.2.17 Sectioned Area Entity 256

4.2.18 Witness Line Entity 259

4.3 Structure Entities 261

4.3.1 Entity Type/Type Number 261

4.3.2 Associativity Definition Entity 262

4.3.3 Associativity Instance Entity 264

4.3.4 Drawing Entity 303

4.3.5 Line Font Definition Entity 308

4.3.6 MACRO Capability 314

4.3.6. 1 General 314

4.3. 6.2 MACRO Syntax 315

4.3.6. 3 MACRO Definition Entity 321

4.3. 6.4 MACRO Instance Entity 334

4.3. 6.5 Examples of MACRO Usage 335

4.3.7 Property Entity 344

4.3.8 Subfigure Definitions 394

4.3.8. 1 Subfigure Definition Entity 394

4. 3. 8. 2 Network Subfigure Definition Entity 395

4.3.9 Subfigure Instances 397

4.3.9. 1 Singular Subfigure Instance Entity 397

4. 3. 9. 2 Rectangular Array Subfigure Instance Entity 397

4. 3.9. 3 Circular Array Subfigure Instance Entity 401

4. 3. 9. 4 Network Subfigure Instance Entity 403

4.3.10 Text Font Definition Entity 405

4.3.11 View Entity 411

4.3.12 External Reference Entity 417

4.3.13 Nodal Load/Constraint Entity 419

4.3.14 Color Definition Entity 421

4.3.15 Text Display Template Entity 422

APPENDIX A: PART FILE EXAMPLES 425

APPENDIX B: ELECTRICAL/ELECTRONIC PRODUCT REPRESENTATION 439

PLANT FLOW SHEET REPRESENTATION 45

3

xiii

APPENDIX C:
APPENDIX D: SPLINE REPRESENTATIONS 469

APPENDIX E: CONIC ARCS 479

APPENDIX F: COLOR SPACE VARIATIONS 481

APPENDIX G: COMPRESSED ASCII FORMAT . 483

REFERENCES 497

GLOSSARY 499

INDEX 513

XIV
LIST OF FIGURES

Figure No.

1-1 Categories of Product Definition 3

2-1 Start Section 17

2-2 Directory Entry (DE) Section 26

2-3 Parameter Data Section 57

2-4 Terminate Section 59

2-5 Compressed ASCII Form 62

2-6 Format of Control Byte 65

2-7 Integer Primitive Format 66

2-8 Real Number Primitive Format 68

2-9 String Constant Primitive Format 70

2-10 Binary General File Structure 71

2-11 Format of Binary Information Section 73

2-12 Format of Start Section 76

2-13 Global Section Format 77

2-14 Format of DE Subrecord 79

2-15 Format of Parameter Section 81

2-16 Format of Terminate Section 83

2-17 Subfigure Structures 86

2-18 General Connectivity Pointer Diagram 87

2-19 MACRO Definition/Instance Structure 91

2-20 External Linkages 94

2-21 Finite Element Modeling File Structure 96

2-22 Finite Element Modeling Logical Structure 97

2-23 Multiple Transformation Cases 99

3-1 Examples of the Circular Arc Entity 110

3-2 Example of the Composite Curve Entity 112

3-3 Examples of the Conic Arc Entity 118

3-4 Examples of the Plane Entity 127

3-5 Single Parent Associativity As Used With a Collection of Bounded Planes 128

3-6 Examples of the Line Entity 131

3-7 Example of the Parametric Spline Curve Entity 134

3-8 Additional Examples of the Parametric Spline Curve Entity 135

3-9 Example of the Parametric Spline Surface Entity 140

3-10 Examples of the Point Entity 145

3-11 Example of the Ruled Surface Entity 148

3-12 Additional Examples of the Ruled Surface Entity 149

3-13 Examples of the Surface of Revolution Entity 153

3-14 Surface of Revolution Start and Terminating Angles 154

3-15 Example of the Tabulated Cylinder Entity 156

3-16 Transformation Matrix Coordinate Systems 159

3-17 Displacement Components 163

3-18 Flash Entities 168

3-19 Node Definition in Each Coordinate System 183

3-20 Finite Element Topology Set 186

3-21 Offset Surface in 3-D Euclidean Space 196

xv
4-1 Construction of ZT Depth of Annotation Entities 208

4-2 Angular Dimension: Construction of Arcs in the

Associated Leaders 210

4-3 Examples of the Angular Dimension Entity 211

4-4 Examples of the Centerline Entity 214

4-5 Examples of the Diameter Dimension Entity 216

4-6 Flag Note 217

4-7 Examples of the Flag Note Entity 219

4-8 Examples of the General Label Entity 222

4-9 Examples of the General Note Entity 224

4-10 Font 1001 225

4-11 Font 1002 226

4-12 Character Set and Octal Code for Font Code Zero 228

4-13 General Note Text Construction 230

4-14 General Note Example of Text Operations 231

4-15 Examples of the Leader Entity 239

4-16 Structure of Leaders Internal to a Dimension 240

4-17 Arrowhead Definitions 241

4-18 Examples of the Linear Dimension Entity 244

4-19 Examples of the Ordinate Dimension Entity 246

4-20 Examples of the Point Dimension Entity 248

4-21 Examples of the Radius Dimension Entity 250

4-22 Examples of the Section Entity 252

4-23 General Symbol Entities 255

4-24 Section Line Patterns 258

4-25 Examples of the Witness Line Entity 260

4-26 Associativity Instance and Entities 268

4-27 Dimensioned Geometry Associativity 283

4-28 Drawing Entity Example 1 305

4-29 Drawing Entity Example 2 306

4-30 Use of Subfigure with Line Fonts 309

4-31 Construction of Line Fonts 313

4-32 Example of Triangle MACRO 337

4-33 Repeated Parallelograms 339

4-34 Concentric Circles 341

4-35 Ground Symbol 342

4-36 Line Widening Examples 350

4-37 Composite Material Configuration 365

4-38 Material Coordinate System 37

1

4-39 Internal Load Sign 37 3 4-40 Subfigure Origin 400

4-41 Example of a Character Definition 409

4-42 Second Character Definition Example 410

4-43 Orthographic Parallel Projection 411

4-44 View Origin 411

4-45 View Volume 414

XVI
A-l Electrical Part Example

A-2 Mechanical Part Example

A-3 Drawing and View Example

B-l General Pointer and Entity Model

B-2 Sample Schematic

B-3 Entity Relations Chart for Sample Schematic (Figure 2)

B-4 Schematic/Physical Diagram for Sample Schematic (Figure 2)

C-l Plant Flow Sheet Example

C-2 Exploded View of Flow Sheet

C-3 Network Subfigure Entities

C-4 Example Entities

C-3 Flow Sheet Pointer Structure

XV1X
LIST OF TABLES

Table No.

2-1 Parameters in the Global Section 18

2-2 Directory Entry Field Description 27

2-3 Entity DE Field Requirements 39

2-

4 Physical Parent/Child Relationships 101

3-

1 Finite Element Topology 185

C-l Entities in PI&D Test Case 457

C-2 Plant Flowsheet Example File 465

xviii
1 GENERAL

1.1 Purpose

This document establishes information structures to be used for the digital

representation and communication of product definition data. Use of the specification established herein permits the compatible exchange of product definition

data used by various CAD/CAM (Computer Aided Design and Computer Aided

Manufacturing) systems.

1 .2 Field of Application

This Specification defines a file structure format, a language format, and the

representation of geometric, topological, and non-geometric product definition

data in these formats. Product definition data represented in these formats will be

exchanged via a variety of physical media. The specific features and protocols for

the communications media are the subject of other standards. The methodology

for representing product definition data in this Specification is extensible and

independent of the modeling methods used.

Section 2 defines the communications file structure and format. It explains the

function of each of the sections of a file. The geometry data representation in

Section 3 deals with two- and three-dimensional edge-vertex models and with

simple surface representations. Section 4 specifies non-geometric representations,

including common drafting practices, data organization methods, and data

definition methods.

In Sections 3 and 4, the product is described in terms of geometric and non- geometric information, with non-geometric information being divided into annotation, definition, and organization. The geometry category consists of elements

such as points, curves, and surfaces that model the product. The annotation

category consists of those elements which are used to clarify or enhance the

geometry, including dimensions, drafting notation, and text. The definition

1
category provides the ability to define specific properties or characteristics of

individual or collections of data entities. The structure category identifies

groupings of elements from geometric, annotation, or property data which are to

be evaluated and manipulated as single items.

1 .3 Concepts of Product Definition

This Specification is concerned with the data required to describe and communicate the essential engineering characteristics of physical objects as manufactured

products. Such products are described in terms of their physical shape, their

dimensions, and information which further describes or explains the product. The

processes which generate or utilize the product definition data typically include

design, engineering analysis, production planning, fabrication, material handling,

assembly, inspection, marketing, and field service.

The requirements for a common data communication format for product definition can be understood in terms of today's CAD/CAM environment. Traditionally,

engineering drawings and associated documentation are used to communicate

product definition data. Commercial interactive graphics systems, originally

developed as aids to producing these two-dimensional drawings, are rapidly

developing sophisticated three-dimensional edge-vertex modeling capability. In

parallel, extensive research work is being conducted in advanced geometric

modeling techniques (e.g., parametric representations and solid primitives) and in

CAM applications utilizing product definition data in manufacturing (e.g., NC

machining and computer-controlled coordinate measurement). The result is rapid

growth of CAD/CAM applications which should be able to exchange product

definition data, but which usually employ incompatible data representations and

formats. In addressing this compatibility problem, this Specification is concerned

with needs and capabilities of current and advanced methods of CAD/CAM product

definition development.

Product definition data may be categorized by their principal roles in defining a product. An example of such a categorization is presented in Figure 1-1. This

Specification specifies communication formats (information structures) for subsets

of the product definition.

2
o ADMINISTRATIVE

Product Identification

Product Structure

o DESIGN/ANALYSIS

Idealized Models

o BASIC SHAPE

Geometric

Topological

o AUGMENTING PHYSICAL CHARACTERISTICS

Dimensions and Tolerances

Intrinsic Properties

o PROCESSING INFORMATION

o PRESENTATIONAL INFORMATION

FIGURE 1-1 CATEGORIES OF PRODUCT DEFINITION

3
1 A Concepts of the File Structure

A format to allow the exchange of a product definition between CAD/CAM

systems must, as a minimum, support the communication of geometric data,

annotation, and organization of the data. The file format defined by this

Specification treats the product definition as a file of entities, each entity being

represented in an application-independent format, to and from which the native

representation of a specific CAD/CAM system can be mapped. The entity

representations provided in this Specification include forms common to the

CAD/CAM systems currently available and forms which support the system

technologies currently emerging.

The fundamental unit of information in the file is the entity. Entities are categorized as geometric and non-geometric. Geometric entities represent the

definition of the physical shape and include points, curves, surfaces, and relations

which are collections of similarly structured entities. Non-geometric entities

typically serve to enrich the model by providing a viewing perspective in which a planar drawing may be composed and by providing annotation and dimensioning

appropriate to the drawing. Non-geometric entities further serve to provide

specific attributes or characteristics for individual or groups of entities and to

provide definitions and instances for groupings of entities. The definitions of these

groupings may reside in another IGES file. Typical non-geometric entities for

drawing definition, annotation, and dimensioning are the view, drawing, general

note, witness line, and leader. Typical non-geometric entities for attributes and

groupings are the property and the associativity entities.

A file consists of five or six sections: Flag (in the case of the binary or compressed

ASCI! format), Start, Global, Directory Entry, Parameter Data, and Terminate. A

file may include any number of entities of any type as required to represent the

product definition. Each entity occurrence consists of a directory entry and a parameter data entry. The directory entry provides an index and includes

descriptive attributes about the data, while the parameter data provides the

specific entity definition. The directory data are organized in fixed fields and are

consistent for all entities to provide simple access to frequently used descriptive

data. The parameter data are entity specific and are variable in length and

4
format. The directory data and parameter data for all entities in the file are organized into separate sections, with pointers providing bi-directional links

between the directory entry and parameter data for each entity. The Specification

provides for groupings whose definitions will be found in a file other than the one in

which they are used.

Each entity defined by the file structure of Section 2 has a specific assigned entity

type number. While not all are assigned at this time, entity numbers 0001 through

0599 and 0700 through 5000 are allocated for specific assignment. Entity type

numbers 0600 through 0699 and 10000 through 99999 are for implementor-defined

(i.e. MACRO) entities. For user defined entities see section 1.5.7. The Index of

Topics includes an alphabetical listing of entity types.

Some entity types include a form number as an attribute. The form number serves

to further define or classify an entity within its specific type.

The entity set includes a provision for associativities and properties. The

associativity provides a mechanism to establish relationships among entities, and to

define the meaning of the relationship. The property allows specific

characteristics, such as color, to be assigned to an entity or collection of entities.

Each entity format includes a structure for an arbitrary number of pointers to

associativities and properties. The file structure provides for both standard

associativities and properties to be included in the Specification, and unique

definitions which will be defined by the user.

1 .5 Concepts of the Information Structures for Wire-Frame Model Descriptions

The wire-frame model refers to the entity set defined by Sections 3 and 4, and

comprises an entity-based product definition file. The entity types, as described in

1.4, are categorized as geometric and non-geometric. In general, the geometric

entities are defined independently of one another (surfaces are an exception).

Features have been provided to define and compose relationships among entities to

enhance the model. The non-geometric entities include structures in which an

entity may be defined by a collection of other entities and structures which are independent.

5
Several entity types which are used to provide relations or definitions are essential

to the file structure methodology of this Specification and are described below.

1.5.1 Property Entity. The PROPERTY entity allows non-geometric numeric or textual

information to be related to any entity. Any entity occurrence may reference one

or more property entity occurrences as required.

Property entities themselves may exist independently of other entities. In this case the property is defined to be a property of the level indicated in the level

field of the directory entry (DE) of the property. This allows for a general

property to apply to all entities of a given level or for the assignment of an

applications function to a level. Because the level field in a DE is also allowed to

point to a property of levels, properties may be applied to multiple levels.

1.5.2 Associativity Entities. The Associativity Entities are designed for use when

several entities must be logically related to one another. Two types of entities are involved here: ASSOCIATIVITY DEFINITION and ASSOCIATIVITY INSTANCE.

The associativity definition entity is used to specify the structure of the logical

relationship, and the associativity instance entity is used to specify the information

involved in a particular occurrence of the relationship.

Some associativities are defined as part of this Specification. These intrinsic

definitions include GROUP and VIEWS VISIBLE associativities, and are defined in

Section 4.3.

1.5.3 View Entity. A drawing or equivalent human-readable representation of the

geometric model of a product is a two-dimensional projection of a selected subset

of the model, together with non-geometric information such as text. The VIEW

entity and VIEWS VISIBLE forms of associativity control such representations.

These provide information for orientation, clipping, line removal, and other

characteristics associated with individual views rather than with the model itself.

1.5.4 Drawing Entity. The DRAWING entity allows a set of views to be identified and

arranged for human presentation. Note that the view and drawing entities contain

only the rules and parameters for extracting drawings from the geometric model.

The actual product definition is not duplicated in various views, eliminating risk of

conflicting or ambiguous information.

6
1.5.5 Transformation Matrix Entity. The TRANSFORMATION MATRIX entity allows

translation and rotation to be applied as needed, to any entity in the construction

of the model and to the development of views and drawings of the model.

1.5.6 MACRO Entities. This Specification includes a MACRO DEFINITION entity for

defining new entity types which may then be used in the defining file in the same

manner as the intrinsically defined entities. A language for defining these new

entity types is specified in 4.3.6.

1.5.7 Implementor Defined Entities. This specification allows implementors to include

entities in their files that are not defined in this document but which have specific user meanings. This feature supports the objective of the Specification to act as an archiving format where the receiving system is the same as the sending system.

In this way, the implementor is able to archive those data forms which may be

unique to a particular system.

From time-to-time, files with such implernentor-defined entities are used with

applications which attempt to edit the file. In this situation, processing problems

can arise because, without an entity definition, the editor cannot know which

parameter values are pointers that have to be updated, and which are simply data

values that should not be updated.

To avoid this problem, implementors should use MACRO definitions and instances

of MACRO entities with entity type numbers in the range of 5001 to 9999

inclusively. (See Section 4.3.6 for information on how to use the MACRO

capabilities of the specification.) This means that for each different implementordefined entity type, there will be a MACRO Definition Entity (Type 306). In order

to accomplish the desired result, all that needs to be present in the parameter data

for these MACRO definitions is the first MACRO statement which defines the

parameter list, and an ENDM statement to terminate the definition.

7
1 .6 Appendices

As an aid to the implementor/user, a series of appendices is included with this

Specification. Appendix A gives three part file examples. Appendix B describes an

electrical-electronic product representation, and Appendix C, a plant flowsheet

representation. Appendix D provides explanation of spline representation and

approaches for conversion techniques. Appendix E discusses the numerical stability

of conic arcs. Appendix F provides mappings between color spaces. A set of

FORTRAN utilities is documented in Appendix G to convert the ASCII Form of

physical file structure to and from the Compressed ASCII Form. In addition, a List

of References, a Glossary and an Index of Topics are also included.

8
DATA FORM - ASCII

2 DATA FORM

2. 1 General

Two different formats are defined to represent IGES data. These formats are ASCII (ANSI68, ANSI74, ANSI77), and Binary. The binary form uses a byte

oriented (bit string) structure which may be especially suited to the

transmission of large files.

The constants, free format rules, file organization, and information structure are discussed in terms of displayed or printed ASCII form. Following this

discussion, the binary form is defined together with necessary changes in constants and file structure.

2.2 ASCII Form

The ASCII form has two format types: a fixed (80 character) line length

format, and a compressed format. In the fixed line length ASCII format, the

entire file is partitioned into 80 character units beginning with the first character in the file. These units are called lines. The term "column" refers

to the character position in a line. The file is divided into sections. The

section identification character shall occupy column 73 of each line. Columns 74 through 80 are specified for the section sequence number of each

line. For the compressed ASCII format, the DIRECTORY ENTRY and

PARAMETER DATA sections are excepted from the above two rules, and will

be defined in a later section. The remaining columns are assigned to fields as defined in the file section description. The term "record" refers to the set of

parameters for one entity within one file section. A record consists of one or more lines.

2.2.1 Sequence Numbers

A sequence number is a string of from one to seven digits and is the means of

indexing lines within the various sections of the data file. The sequence

numbers for each section begin with 1 (0000001) and continue sequentially

without interruption to the value corresponding to the number of lines in the

section. A sequence number may have either leading zeros or leading blanks

and is right-justified in its field in the line (columns 74-80).

9
DATA FORM - ASCII

The sequence number is preceded in the line by a single letter code in column

73 identifying the section in which the line resides:

Section Letter Code

Flag (optional) B or C

Start S

Global G

Directory Entry D

Parameter Data P

Terminate T

Letter codes "B" and "C" are used to signify binary (see section 2.4.2. 1) and

compressed ASCII (see section 2.3.1) information, respectively.

2.2.2 Constants

This specification defines five types of constants: integer (or fixed point),

real (or floating point), string, pointer, and language statement. Regardless

of whether the constants appear in a fixed or free format in the data file,

certain rules apply to their formation and interpretation:

o Blanks are only significant in string and language statement constants. A numeric field of all blanks is considered to denote the default value

for that field. No blanks are allowed between the beginning of a numeric constant (i.e., its sign, first numeric digit, or decimal point)

and the end of that constant (i.e., the last character position allocated

in fixed format or the delimiter character in free format). Leading

blanks in the parameters containing numeric constants are ignored.

Blanks between the end of any constant and the delimiter following the

constant are not allowed.

o Numeric constants cannot contain embedded commas.

o The absolute magnitude of an integer constant may not exceed the

value 2**(N-1)-1, where N is the number of bits used to represent the

integer value (Global parameter 7).

10
DATA FORM - ASCII

Similarly, the absolute magnitude and precision of a real constant may

not exceed that indicated by Global parameters 8-9 (for single

precision) and 10-11 (for double precision).

o Only string and language statement constants may cross field/line

boundaries. When such a constant does cross a boundary, it is considered to extend to the last usable column on the current line and

then to continue with the first column on the succeeding line. The last usable column on lines in the Parameter Data section is column 64; on

lines in all other sections it is column 72. A string constant may not be

broken before the Hollerith delimiter (H).

o A numeric constant may be either signed or unsigned. If signed, the

leading plus or minus determines the sense of the constant. If unsigned,

the sense is assumed to be non-negative.

2.2.2. 1 Integer Constants

An integer constant (sometimes called a fixed point constant) is always an exact representation of an integer value. It may assume a positive, negative

or zero value. It may assume only an integral value.

The form of an integer constant is an optional sign followed by a non-empty

string of digits. The digit string is interpreted as a decimal number.

i The following are examples of valid integer constants (assuming the value of

Global parameter 7 is 32)

1 150 2147483647 +3451

0 -10 -2147483647

11
DATA FORM - ASCII

2. 2. 2.2 Real Constants

A real constant (sometimes called a floating point constant) is a processor

approximation of the value of a real number. It may assume a positive,

negative, or zero value. A real constant may be either a basic real

constant, a basic real constant followed by an exponent, or an integer

constant followed by an exponent.

A real constant may be of either single or double precision. The distinction

is in the precision of the processor's representation of the real number

which is specified in Global parameters 8 through 11. A double precision

constant may be either a basic real constant followed by a double precision

exponent, or an integer constant followed by a double precision exponent.

The form of a basic real constant is, in order, an optional sign, an integer

part, a decimal point, and a fractional part. Both the integer part and the

fractional part are strings of digits; either of these parts may be omitted

but not both. A basic real constant is interpreted as a decimal number.

The form of a real exponent is the letter E followed by an optionally signed

integer constant. A real exponent denotes a decimal power of ten by which

the preceding constant is multiplied.

The form of a double precision exponent is the letter D followed by an

optionally signed integer constant. A double precision exponent denotes a decimal power of ten by which the preceding constant is multiplied.

The following are examples of valid real constants:

256.091

1.36E1

0. -13E-02

-0.58

0.1E-3

+4.21

l.E+4

145.98763D4 -2145.980001D-5 0.123456789D+09 -.43E2

12
DATA FORM - ASCII

2.2.2.3 String Constants

String constants are represented in the Hollerith form as specified in Appendix C of the current FORTRAN standard (ANSI78). A string constant

is an arbitrary sequence of ASCII characters. Blanks, parameter

delimiters, and record delimiters are treated simply as characters within

the string. There is no limit on the length of a string constant.

The form of a string constant is a non-zero, unsigned integer constant

(character count), followed by the letter H, followed by a string of

characters consisting of the number of contiguous characters specified by

the character count.

The following are examples of valid string constants;

3H123 10HABC.,;ABCD

8HCU57E03 12H HELLO THERE

2.2.2A Pointer Constants

A pointer constant is a non-empty string of from one to seven digits.

Pointer constants are used to identify a line in either the same or a

different section of the data file. The magnitude of the pointer constant

corresponds to the sequence number of the referenced line, and the

referenced file section is determined by the context of the reference.

Pointer constants are unsigned except where they are alternative

parameters in a field. Pointer constants whose magnitude requires fewer

than seven digits may use leading zeros or leading blanks in fixed format

fields.

2.2.2. 5 Language Statement Constants

The language statement constant is an arbitrary character string made up

of alphanumeric, punctuation, and blank characters from the ASCII

character set. The language statement constant is not preceded by the

13
DATA FORM - ASCII

character count and the Hollerith delimiter H as is the string constant. Section 4.3.6 defines the syntax of the language statement constant as used

for the MACRO entity. The length of the language statement constant is determined by means of the Parameter Data line count in the Directory

Entry record for the entity (see Directory Entry parameter 14).

2.2.3 Rules for Forming and Interpreting Free Formatted Data

The data in several sections of a file may be entered in free format. The

free format will apply to a range of columns of a line in the section and to the same range of columns of successive lines as needed. This free format

feature allows the specification of parameters in the prescribed order

without restricting the placement of the parameter to a particular location on a line. When free format is permitted, the following rules apply (in

addition to those in section 2.2.2) :

o The parameter delimiter (Global parameter 1 - defaulting to a comma) is used to separate parameters.

o The record delimiter (Global parameter 2 - defaulting to a semicolon)

is used to terminate the record (i.e., to terminate a list of

parameters).

o When two parameter delimiters, or a parameter and record delimiter,

appear adjacent to each other, or are separated by only blanks, the

parameter is considered not to have been specified in the file and

should be given its default value. Unless specifically noted, the

default value for a numeric parameter is zero, and the default value

for a string parameter is null. It is the responsibility of the

preprocessor to ensure that these default values are reasonable for

the particular parameter in question.

o When a record delimiter appears before the list of parameters is complete, all remaining parameters should be given their default

values (see above for a discussion of assigning default values).

14
DATA FORM - ASCII

o The end of the data portion of the physical line (i.e., column 72 in the

Global Section, and column 64 in the Parameter Data Section) is not

to be construed to act as either a parameter delimiter or a record

delimiter.

o The parameter delimiter and record delimiter characters do not

maintain their special significance when included within a string

constant.

o A numeric constant, including its trailing delimiter, cannot extend

across a line boundary.

15
DATA FORM — ASCII Start Section

2.2 .4 File Structure

The file contains six subsections which must appear in order as follows:

a. Flag Section (optional)

b. Start Section

c. Global Section

d. Directory Entry Section

e. Parameter Data Section

f. Terminate Section.

The Flag Section of the file is used, when present, to indicate that the file is

in the Binary Form (2.4.2. 1) or in the Compressed ASCII Form (2.3.1).

2.2.4. 1 Start Section. The start section of the file is designed to provide a manreadable prolog to the file. There must be at least one start record, and all records in the section must have the letter S in column 73 and a sequence

number in column 74 through 80 (See 2.2.1). The information in columns 1 through 72 is not formatted in any special way except that the ASCII

character set must be used. An example of a start section is shown in Figure

2- 1 .

16
DATA FORM - ASCII Start Section

START SECTION

• 72 73 80

THIS SECTION IS A MAN READABLE SOOOOOOI

PROLOG TO THE FILE. IT CAN CONTAIN S0000002

AN ARBITRARY NUMBER OF LINES

••

•

S0000003

•

•

•

•

•

• USING ASCII CHARACTERS IN COLUMNS 1-72.

•

•

• S000000N

FIG. 2-1 START SECTION

17
DATA FORM ASCII - Global Section

2.2. 4. 2 Global Section

The global section of the file contains the information describing the preprocessor and information needed by the post-processor to handle the file. All records in the global section shall contain the letter G in column 73 and a sequence number (See 2.2.1). The first two global parameters are used to define the parameter delimiter and record delimiter characters if necessary.

The default characters are "comma" and "semicolon" respectively.

The parameters for the global section are input in free format as described in

2.2.3. As implied in 2.2.3, the global parameters will end with the record

delimiter. If the global section specifies new delimiter characters, they take

over immediately and are used in the global section as well as the rest of the

file. This is possible, because the comma and semicolon delimiter

specifications are the first two global parameters. The parameters in the

global section are described in Table 2-1 and the paragraphs that follow.

Unless explicitly stated', no defaults are provided.

TABLE 2-1 PARAMETERS IN THE GLOBAL SECTION

INDEX FIELD TYPE DESCRIPTION

1 String Parameter delimiter character (default is comma)

2 String Record delimiter character (default is semicolon)

3 String Product identification from sending system

4 String File name

5 String System ID

6 String Preprocessor version

18
7

S

9

10

11

12

13

14

15

16

17

18

DATA FORM - ASCII - Global Section

Integer

Integer

Integer

Integer

Integer

String

Real

Integer

String

Integer

Real

String

Number of bits for integer representation

Maximum power of ten representable in a

single precision floating point number on the

sending system

Number of significant digits in a single

precision floating point number on the sending

system

Maximum power of ten representable in a double precision floating point number on the

sending system

Number of significant digits in a double

precision floating point number on the sending

system

Product identification for the receiving

system

Model space scale

(example: .125 indicates a ratio of 1 unit

model space to 8 units real world)

Unit flag

Units. Ten values of the unit flag have been

defined. (See 2.2.4.2.15).

Maximum number of line weight gradations (1-

32768). Refer to the directory entry parameter 12 (See 2. 2.4. 3) for use of this parameter.

Size of maximum line width in units. Refer to

the directory entry parameter 12 (See 2.2.4.3)

for use of this parameter.

Date & time of file generation

13HYYMMDD.HHNNSS where:

YY is year (last 2 digits)

MM is month (01-12)

DD is day (01-31)

HH is hour (00-23)

NN is minute (00-59)

SS is second (00-59)

19
DATA FORM - ASCII Global Section

19 Real Minimum user-intended resolution or granularity of the model expressed in units defined

by parameter 13 (example .0001)

20 Real Approximate maximum coordinate value oc- curring in the model expressed in units defined

by parameter 15. (Example: 1000.0 means for

all coordinates / X|, |y|, |z/^ 1000.)

21 String Name of author

22 String Organization

23 Integer Integer value corresponding to the version of

IGES used to create this file. (See 2.2.4.2.23

for Correspondence Table.)

24 Integer Drafting standard in compliance to which the

data encoded in this file was generated. (See

2.2.4.2.24)

20
DATA FORM - ASCII - Global Section

2.2. 4.2.1 Parameter Delimiter Character. This parameter indicates which character is used to separate parameter values in the Global and Parameter Data

sections. Each occurrence of this character denotes the end of the current

parameter and the start of the next parameter. Two exceptions exist:

(1) string constants in which the delimiter character may be part of the

string; (2) language statements in which the delimiter character may be a

part of the language syntax. The default value is a comma. See 2.2.3.

2.2.4.2.2 Record Delimiter. This parameter indicates which character is used to denote the end of a list of parameters in the Global section and

each Parameter Data section entry. Each occurrence of this character

denotes the end of the current parameter list. Two exceptions exist: (1) string constants in which the delimiter character may be part of the

string; (2) language statements in which the delimiter character

may be a part of the language syntax. The default value is a semicolon.

See 2.2.3.

2.2. 4. 2.

3

Product Identification From Sender. This is the name of the identifier

which is used by the sender to reference this product.

2.2. 4.2.

4

File Name. This is the name of the IGES file.

2.2. 4. 2.

5

System ID. This parameter is an identification code which should uniquely

identify the system which generated this file. It includes both the name of

the system and the version of software on that system.

2.2. 4. 2.

6

Preprocessor Version. This parameter identifies the version of the preprocessor

software which created this file.

2.2. 4. 2.

7

Number of Bits for Integer Representation. This parameter indicates how

many bits are present in the integer representation of the sending system.

This parameter sets limits on the range of values for integer parameters in

the file.

2.2. 4.2.

8

Single Precision Magnitude. This parameter indicates the maximum power of

ten which may be represented as a single precision floating point number on the

sending system

.

21
DATA FORM - ASCII - Global Section

2.2. 4. 2.

9

2.2.4.2.10

2.2.4.2.11

2.2.4.2.12

2.2.4.2.13

2.2.4.2.14

Single Precision Significance. This parameter indicates the number of

decimal digits of significance which can be accurately represented in the

single precision floating point representation on the sending system.

Double Precision Magnitude. This parameter indicates the maximum power of

ten which may be represented as a double precision floating point number on the

sending system.

Double Precision Significance. This parameter indicates the number of decimal

digits of significance which can be accurately represented in the double

precision floating point representation on the sending system.

Example: For an IEEE 754-1985 (IEEE85) floating point representation with

32 bits, the magnitude and significance parameters have the values 38 and 6,

respectively; for a representation with 64 bits, the values are 308 and 15,

respectively.

Product Identification for the Receiver. This is the name or identifier

which is intended to be used by the receiver to reference this product.

Model Space Scale. The ratio of model space to real world space.

Unit Flag. An integer value denoting the measuring system used in the file. The values in the file are assumed to be:

Unit flag 1 (Inches)

2 (Millimeters)

3 (See Parameter 15 for name of units)

4 (Feet)

5 (Miles)

6 (Meters)

7 (Kilometers)

8 (Mils, i.e. 0.001 inch)

9 (Microns)

10 (Centimeters)

1 1 (Microinches)

This is the controlling definition of units. A value of '3' should only be used

when it is intended to transfer data to a system using the same units, in

22
DATA FORM - ASCII - Global Section

which case parameter 15 must be used to provide additional information as

to those units.

2.2.4.2.15 Units. A string constant naming the model units in the system, e.g.:

2HIN or 4HINCH (model units are inches)

2HMM (model units are millimeters)

2HFT (model units are feet)

2HMI (model units are miles)

1HM (model units are meters)

2HKM (model units are kilometers)

3HMIL (model units are mils)

2HUM (model units are microns)

2HCM (model units are centimeters)

3HUIN (model units are microinches)

When the unit flag is given a value of 3, the string constant naming the

desired unit should conform to MIL-STD-12D, (DOD12D) or ANSI/IEEE 260,

(IEEE260).

2.2.4.2.16 Maximum Number of Line Weight Gradations. This is the number of equal

subdivisions of line thickness.

2.2.4.2.17 Size of Maximum Line Width in Units. This is the actual width of the

thickest line possible in the (scaled) file.

2.2.4.2.18 Date and Time of File Generation. This is a time stamp of when the file was created.

2.2.4.2.19 Minimum User-Intended Resolution. This parameter indicates the smallest

distance in model space units that the system should consider as discernable. Coordinate locations in the file which are less than this distance

apart should be considered to be coincident.

2.2.4.2.20 Approximate Maximum Coordinate Value. This is the upper bound on the

values of ail coordinate data actually occurring in this model. The absolute

magnitude of each of the coordinates in this model is less than or equal to

this value.

23
DATA FORM ASCII - Global Section

2.2.4.2.21 Name of Author. The name of the person responsible for the generation of

the data contained in this file.

2.2.4.2.22 Organization. The organization or group with whom the author is associated.

2.2.4.2.23 Version Number. Each version of IGES is assigned a unique integer value

corresponding to that version. This field contains the integer value

corresponding to the version of IGES used to create this file. The

correspondences are specified in the table below.

VALUE IGES VERSION

1 1.0

2 ANSI Y14.26M - 1981

3 2.0

4 3.0

If no valid integer value is entered in this field, the default value of 3

/ (corresponding to IGES Version 2.0) should be assumed.

2.2.4.2.24 Drafting standard code. The drafting standard according to which the data

in this file was generated.

0 None No standard specified

1 ISO International Organization for Standardization

2 AFNOR - French Association for Standardization

3 ANSI American National Standards Institute

4 BSI British Standards Institute

5 CSA Canadian Standards Association

6 DIN German Institute for Standardization

7 JIS Japanese Institute for Standardization

24
DATA FORM - ASCII - Directory Entry

Section

2. 2. 4. 3 Directory Entry Section

The directory entry section has one directory entry for each entity in the

file. The directory entry for each entity is fixed in size and contains twenty

fields of eight characters each spread across two consecutive eighty character lines. Data are right justified in each field. With the exception of the

fields numbered 10, 16, 17, IS, and 20, entries in all fields in this section will

be either integer constants or pointer constants. In this section, the word

"number" is sometimes used in place of the phrase "integer constant."

The purposes of the directory entry section are to provide an index for the

file and to contain attribute information for each entity. The order of the

directory entries within the directory entry section is arbitrary with the

exception that a definition entity must precede all of its instances.

Within the directory entry section, a field consisting wholly of blanks is to be

considered to have not been specified and should be given a default value

where possible. Default values are not allowed in fields 1, 2, 10, 11, 14, and

20. The actual values to be assigned as defaults will vary depending on the

entity type. This rule does not apply to compressed ASCII.

Some of the fields in the directory entry can contain either an attribute value

directly, or a pointer to a set of such values. In these fields, a positive value

indicates an integer constant, while for a negative value, the absolute value

should be taken and the result interpreted as a pointer constant.

Since zero is not a valid pointer constant value, a zero in a field requiring a

pointer is not permitted unless a specific interpretation has been allowed for

in this Specification.

Table 2-2 and the following paragraphs describe each directory entry field.

For those fields accommodating either an attribute value or a poii er, there

are two descriptions given. Figure 2-2 gives an abbreviated listing of the

fields making up the directory entry for each entity.

25
DIRECTORY

ENTRY

CDE)

SECTION

DATA FORM - ASCII - Directory Entry

Section

om

r—

SEQUENCE NUMBER D.# 10 SEQUENCE NUMBER D.#

+l

20

i CM

p—

40

CO

STATUS NUMBER # s ENTITY SUBSCRIPT # 19

co

f—

40

LABEL DISPLAY 8 ENTITY LABEL 18

40

IO

er>

TRANSFOR- MATION MATRIX 1

S

g —

TF

3?UJ A, 4©

:> ©

s

1

*

OS ©'sS”

PO

PO

i

LEVEL 5 FORM # 15

L

CVJ

40

cvj r

i

LINE

FONT

PATTERN #.- 4 PARA- METER LINE COUNT # 14

*HP

CVJ

STRUCTURE 3 COLOR 13

com

PARAMETER DATA *» 2 LINE WEIGHT # 12

CO >-

UJ

ENTITY TYPE # II LINE I LINE 2

iCO

«*(9

CO

ez

I %• I A ^

%

oac.

r-j

iO

CVJ

I C\J

d

26

DIRECTORY

ENTRY

(DE)

SECTION
DATA FORM - ASCII - Directory Entry

Section

TABLE 2-2 DIRECTORY ENTRY FIELD DESCRIPTION

NO. FIELD NAME MEANING AND NOTES

1 Entity Type Number Identifies the entity type.

2 Parameter Pointer to the first line of the parameter data

Data record for the entity. The letter P is not

included.

3 Structure Pointer to the directory entry of the definition

entity that specifies this entity's meaning.

The letter D is not included. The integer

values 0, 1, and 2 are permissible in this field

but should be disregarded. (See 2.2.4. 3. 3)

4 Line Font Pattern Line font pattern or pointer to the directory

/ entry of a line font definition entity.

5 Level Number of the level upon which the entity

resides, or a pointer to the directory entry of a property entity (form 1) which contains a list of levels upon which the entity resides.

6 View Pointer to the directory entry of a view

entity, or pointer to a views visible

associativity instance, or integer zero

(default).

7 Transformation Matrix Pointer to the directory entry of a trans- formation matrix (type number 124) used in defining this entity; zero (default) implies the

identity transformation matrix and zero

translation vector will be used.

27
DATA FORM ASCII - Directory Entry

Section

8 Label Display

Associativity

Pointer to the directory entry of a label

display associativity (Entity 402 Form 5).

9 Status Number Provides four two-digit status values which

are entered from left to right in the status number field in the order given below.

1-2 Blank Status

00 Visible

01 Blanked

3-4 Subordinate Entity Switch

00 Independent

01 Physically Dependent

02 Logically Dependent

03 Both (01) and (02)

5-6 Entity Use Flag

00 Geometry

01 Annotation

02 Definition

03 Other

04 Logical/Positional

05 2D Parametric

7-8 Hierarchy

00 Global top down

01 Global defer

02 Use hierarchy property

10 Section Code and

Sequence Number

Physical count of this line from the beginning

of the directory entry section, preceded by the

letter D (odd number).

11 Entity Type Number (Same as Field 1.)

28
DATA FORM - ASCII - Directory Entry

Section

12 Line Weight Number System display thickness; given as a gradation

value in the range of 0 to the maximum

(parameter 16 of the global section).

13 Color Number Color number or pointer to the directory entry

of a color definition entity.

14 Parameter Line Number of lines in the parameter data record

Count Number for this entity.

15 Form Number Certain entities have different interpretations. These interpretations are uniquely identified by a form number. Possible form numbers are listed within each entity description.

16-17 Reserved for

future use

18 Entity Label Up to eight alphanumeric characters (right

justified).

19 Entity Subscript

Number

1 to 8 digit unsigned number associated with

the label.

20 Section Code and Same meaning as field 10

Sequence Number (even number).

29
DATA FORM - ASCII - Directory Entry

Section

2.2.4.3.1 Entity Type Number. The integer number indicating the type of entity.

2. 2. 4. 3.

2

Parameter Data. This is the sequence number of the first parameter data

record for this entity. The letter P is not included.

2. 2. 4. 3.

3

Structure. Non-negative integer values are permitted in this field, but should

be disregarded. (In versions prior to Version 3.0, non-negative integers were used in this field to designate version numbers.) For a negative

value, the absolute value of this field is interpreted as a pointer to the

structure definition entity which specifies the schema for this entity type

number.

2. 2. 4. 3.

4

Line Font Pattern. This indicates a display pattern to be used to display a geometric entity. A positive value indicates that the receiving system's

corresponding version of the solid, dashed, phantom and centerline fonts

should be used. A negative value indicates that the absolute value should be

interpreted as a pointer to a line font definition entity (type 304) which

provides the information specifying the display pattern.

1 = Solid 3 = Phantom

2 = Dashed 4 = Centerline

2.2. 4.3.

3

Level. This value specifies a graphic display level or levels to be associated

with this entity. A positive value indicates the graphic level this entity

exists on. A negative value indicates the absolute value is a pointer to a property entity (type 406, form 1) which contains a list of levels to be

associated with the entity. This feature allows an entity to exist on multiple

graphic levels.

2. 2. 4. 3.

6

View. Three options exist. This value is either a pointer to the directory

entry of a view entity (type 410), a pointer to an associativity instance (type

402, form 3 or 4, views visible), or the integer zero (default). The first option

applies when the entity is visible in a single view. The second option applies

when the entity is visible in more than one view. (Form 4 applies when the

display characteristics of the entity are view dependent.) The third option

applies when the entity is displayed with the same characteristics in all

views.

30
DATA FORM - ASCII - Directory Entry

Section

2.2.4. 3.7 Transformation Matrix. This value is either a pointer to the directory entry

of a Transformation Matrix entity (type 124) or the integer zero (default).

Zero implies the identity rotation matrix and zero translation vector will be

used. The Transformation Matrix entity provides Form Numbers according to

the form of the transformation matrix. See Section 3.14.

2.2.4.3.8 Label Display Associativity. This is a pointer to the directory entry of a

label display associativity (type 402, form 5) which defines how the entity's

label and subscript are to be displayed in different views.

2.2. 4. 3. 9 Status Number. This value contains four pieces of information which are concatenated into a single integer number. The four two-digit values are concatenated from left to right in the order given below.

2.2. 4. 3.9.1 Blank Status. This value defines whether the entity is meant to be visible on

the output device of the receiving system. A value of 00 implies the entity is

to be displayed and a value of 01 implies the entity is not to be displayed.

2. 2. 4. 3. 9. 2 Subordinate Entity Switch. This value indicates whether or not the entity is referenced by other entities in the file; and, if so, what type of relationship

exists. An entity can be independent, physically dependent, logically

dependent, or physically and logically dependent. The values are defined as

follows:

00: Independent. The entity is not referenced (i.e., pointed to) by

any other entities in the file. It can exist alone in the native

database.

01: Physically Dependent. This entity (the child) is referenced by

another entity (the parent) in the file. The child cannot exist

unless the parent exists. The matrix pointed to by the entity

(as a child) must be applied to the entity's definition in order to determine its location in the parent's definition space.

Entity A is subordinate to entity B if, and only if, the parameter data entry

of entity B contains a pointer to entity A. This implies that entities are NOT subordinate to the view (or views visible associativity) entity that

defines the view within which the entity is displayed.

31
DATA FORM - ASCII - Directory Entry

Section

The structure formed by a parent entity and its physically subordinate

components is indivisible and may therefore be considered to form a single

entity.

The following are examples of physically subordinate entities:

o A leader line entity pointed to by a subordinate entity, o A line entity pointed to by a plane entity, o A circular arc entity pointed to by a composite curve entity, o A composite curve entity pointed to by a subfigure definition (note

that the subfigure definition would NOT point to the constituent

entities of the composite curve).

Consider the following example:

o Entity A is physically subordinate to entity B. o Entity A points to a transformation matrix Ml.

o Transformation matrix Ml points to a transformation matrix M2,

o Entity B is subordinate to a subfigure definition entity C.

o Entity B points to a transformation matrix M3,

o Entity C is instanced in a subfigure instance D.

o The parameter data of entity D specifies its scale factor as Sd and

position as (Sd,Yd,Zd). o Entity D points to a transformation matrix M4.

o Entity D points to a view entity E. o The view scale factor defined in the parameter data of entity E is Se. o Entity E occurs within a drawing F at drawing coordinates (Fx,Fy). o Entity E points to a transformation matrix M5.

In order to obtain the drawing space coordinates of entity A, the following

operations are performed:

1. The coordinates of entity A are transformed by Ml.

2. The coordinates resulting from the preceeding step are transformed

by M2.

3. The coordinates resulting from the preceeding step are transformed

by M3.

32
DATA FORM - ASCII - Directory Entry

Section

4. The coordinates resulting from the preceeding step are scaled by Sd.

5. The coordinates resulting from the preceeding step are transformed

by M4.

6. The coordinates resulting from the preceeding step are translated by

the vector (Xd,Yd,Zd). The coordinates resulting from this step are the model space coordinates of entity A.

7. The coordinates resulting from the preceeding step are transformed

by M5.

8. The coordinates resulting from the preceeding step are scaled by the

scale factor Se.

9. The coordinates resulting from the preceeding step are translated by

the vector (Fx,Fy).

02: Logically Dependent. This entity (the child) can exist alone in the native database, but is referenced by some sort of logical

grouping entity, or entities (the parents), such as

associativities. The matrix pointed to by the parent entity has no effect on the location of the child.

An example of a logically subordinate entity is that of a line entity pointed

to by a group associativity entity.

03: Both Physically and Logically Dependent. This entity is physically dependent upon another entity in the file and is subject to the physical dependency rules described above. This

entity is also referenced by one or more logical grouping

entities, and is also subject to the logical dependency rules

described above. Additionally, an entity cannot be physically

and logically dependent upon the same parent entity.

The case of an entity being both logically and physically subordinate refers

to the fact that the transformation matrix pointed to by a parent entity is not applied to its logically subordinate children.

An example of a logically and physically subordinate entity is that of a line

entity occuring in a subfigure definition and pointed to by a group

associativity entity.

33
DATA FORM - ASCII - Directory Entry

Section

2. 2.4. 3.9.3 Entity Use Flag. This value indicates the intent of the entity. It classifies

the entity as intending to serve in the following manners:

00 Geometry. This is the default value. The entity is used to define the geometry of the structure of the product.

01 Annotation. The entity is used to add annotation or description

to the file. This includes geometric entities used to form

annotation or description.

02 Definition. The entity is used in definition structures of the

file. It is not intended to be valid outside of the other entities

which reference the definition structure. An example is the

entities in a subfigure definition which are intended to be valid

in the subfigure instances that reference the subfigure

definition. This class includes all entities in the 300 entity type

number range.

03 Other. The entity is being used for other purposes such as defining structural features in the file. This category

corresponds roughly to the 400 range, but there are exceptions.

For example, a subfigure instance (408) could define geometry,

thus having an entity use flag = 0 or it could define a drawing

format, thus having an entity use flag = 01. An associativity

instance would ordinarily have the value 03. Exceptions include

associativities concerned with display where it would have the

value 01. The view and drawing entities have value 01

(annotation). Transformation depends on its use: If used only

for annotation (e.g., defining a view) the value is 01; if used for

defining geometry or for defining geometry and annotation,

value is 00.

34
DATA FORM - ASCII - Directory Entry

Se.ction

04 Logical/Positional. The entity is used as a logical and/or

positional reference by other entities. This usage does not

prevent the entity from referencing other entities or having its own attributes. Some entities which may be instanced in this

way are nodes, connect points, and points when their primary

use is as a reference.

05 2D Parametric. The entity takes its values in two dimensional

XY parameter space considered as a subset of three

dimensional XYZ space by ignoring the Z coordinate. The

transformation matrix from definition space to parameter

space must be 2-dimensional (i.e., in entity 124, section 3.14.8,

T3=R

i

3

=P- 3 i=R 32=R.23 = Q'0 and R33=1.0). In addition, the

coordinates do not have units of length (i.e., the model space

scale and units conversion do not apply). This is intended for use in defining curves on surfaces.

2. 2. 4. 3. 9. 4 Hierarchy. This value indicates the relationship between entities in a

hierarchical structure and is used to determine which entity's directory

entry attributes should be applied. It applies to line font, view, entity

level, blank status, line weight, and color number. Three values are

provided:

00: All the above directory entry attributes will apply to entities

physically subordinate to this entity.

01: None of the above directory entry attributes of this entity will

apply to physically subordinate entities. The physically

subordinate entities will use their own directory entity

attributes.

02: Individual setting of each of above direct entry attributes are allowed. A hierarchy property entity form 10 (see 4.3.7.3.10)

specifies whether 00 or 01 is applied for each directory entry

attribute to physically subordinate entities.

35
DATA FORM - ASCII - Directory Entry

Section

Example: If an entity A has 00 in its DE status digits 7 and 8,

all entities subordinate to A will have the attributes

assigned to A. Consequently, the attributes assigned

to all entities subordinate to A are ignored.

If an entity A has 01 in its DE status digits 7 and 8,

the entities immediately subordinate to A will

retain their own status. Consequently, the

attributes assigned to A are ignored.

2.2.4.3.10 Sequence Number. A number which specifies the position of the DE line in the directory entry section. The sequence number of the first DE line for

any entity is always odd and the sequence number of the second line is always even.

2.2.4.3.11 Entity Type Number. This is the same as Field 1.

2.2.4.3.12 Line Weight Number. This value denotes the thickness (or width) with

which an entity should be displayed. A specific series of possible

thicknesses are specified by global parameters 16 and 17. The largest

thickness possible is that specified in global parameter 17 and is denoted by

setting this value equal to the value in global parameter 16. The smallest

thickness possible is equal to the result of dividing global parameter 17 by

global parameter 16 and is denoted by setting this value equal to 1. Thicknesses between the smelliest and largest thickness are available in increments equal to the smallest possible thickness and are denoted by

setting this value equal to the integer number of (adjacent) increments

required.

Thus, display thickness is: Line Weight Number * (Global parameter 17/Global parameter 16)

A value of 0 indicates that the default line weight display of the receiving

system is to be used.

36
DATA FORM - ASCII - Directory Entry

Section

2.2.4.3.13 Color Number. Field 13 is a color number and is used for specifying color

when the precise shade is unimportant or is a pointer to a more precise

color definition. It is up to the receiving system to generate colors which

approximately fit the following description.

Color No. Color

0

1

2

3

4

56

7

8

No color assigned

Black

Red

Green

Blue

Yellow

Magenta

Cyan

White

If the color number is negative, its absolute value is a pointer to the

directory entry of a color definition entity (type 314).

2.2.4.3.14 Parameter Line Count Number. This is the number of lines in the

parameter data section which contain the parameter data record for this

entity.

2.2.4.3.15 Form Number. This value indicates an individual interpretation of the

entity to be used when processing the parameter data for this entity. Some

entity types allow multiple interpretations of their parameter data. This

parameter along with the entity type number uniquely identify the interpretation of the parameter data.

2.2.4.3.16 Reserved Field. This field is reserved for future use and should be left blank.

2.2.4.3.17 Reserved Field. Same as Field 16.

2.2.4.3.18 Entity Label. This is the application-specified alphanumeric identifier or name for this entity. It is used in conjunction with the entity subscript

number (Field 19) to provide the application-specified alphanumeric

identifier for the entity.

37
DATA FORM - ASCII Directory Entry

Section

2. 2. 4.3. 19 Entity Subscript Number. This is a numeric qualifier for the entity label

(Field 18).

2.2.4.3.20 Sequence Number. Same as 2.2.4.3.10

2.2.4.3.21 Table 2-3 summarizes DE Field Requirements for mechanical product

entities.

Each DE field is placed in one of three following categories.

Ignore

The field has no meaning for this entity. The preprocessor should set the

field to 0 or blank. The postprocessor should ignore the field altogether.

Valid: May be defaulted to

0 or blank is a valid setting for this field. If the field is blank, the

postprocessor will interpret it a 0 or blank as specified. Other valid

settings must be set explicitly by the preprocessor.

Valid: Non-zero required

A non-zero value must be set by the preprocessor. Zero or blank are not

valid settings for this field, therefore no default is allowed.

38
DATA FORM - ASCII - Directory Entry

Section

TABLE 2-3 ENTITY DE FIELD REQUIREMENTS

Entity Type(s): 100, 104, 106 (Forms 1-3, 11-13, 63) 110, 112, 116, 126, 114, 108, 118, 120, 122, 130, 140,

142, 144 ATTRIBUTE IGNORE VALID:

May be

defaulted to

VALID:

Non-Zero

Required

COMMENT

1. TYPE X

2. PD ptr. X

3. Structure X

4. Line Font X Ignored for 116, 106

(Forms 1, 2, 3)

5. Level 0

6. View ptr. 0 0 means display in all views

7. Matrix ptr. 0

8. Label ptr. 0

9a. Blank S 00

9b. Subord Sw 00

9c. Entity use 00 00, 01, 05 are the only

valid values. 01 implies

the entity is used as annotation rather than

defining geometry.

9d. Hierarchy X

10. Seq. num. X

11. TYPE X

12. Line wt. 0 A value of 0 means to use

the receiving system's

default line weight.

13. Color 0 A value of 0 means any

color may be used.

14. PD Count X

15. Form 0 Non-zero required for 106

16. Reserved X

17. Reserved X

18. Label Blank

19. Subscript 0

20. Seq. num. X

39
DATA FORM - ASCII - Directory Entry

Section

Entity Type(s): 102 ATTRIBUTE IGNORE VALID:

May be

defaulted to

VALID:

Non-Zero

Required

COMMENT

1. TYPE X

2. PD ptr. X

3. Structure X

4. Line Font X Note 1

5. Level 0 Note 1

6. View ptr. 0 Note 1

7. Matrix ptr. 0

8. Label ptr. 0

9a. Blank S 00 Note 1

9b. Subord Sw 00

9c. Entity use 00

9d. Hierarchy 00

10. Seq. num. X

11. TYPE X

12. Line wt. 0 Note 1

13. Color 0 Note 1

14. PD Count X

15. Form 0

16. Reserved X

17. Reserved X

18. Label Blank

19. Subscript 0

20. Seq. num. X

Notes:

1. This field is ignored if the hierarchy value for field is 01.

40
DATA FORM - ASCII Directory Entry

Section

Entity Type(s): 124 (Forms 0,1) ATTRIBUTE IGNORE VALID:

May be

defaulted to

VALID:

Non-Zero

Required

COMMENT

1. TYPE X

2. PD ptr. X

3. Structure X

4. Line Font X

5. Level X

6. View ptr. X

7. Matrix ptr. 0

8. Label ptr. X

9a. Blank S X

9b. Subord Sw X

9c. Entity use X

9d. Hierarchy X

10. Seq. num. X

11. TYPE X

12. Line wt. X

13. Color X

14. PD Count X

15. Form 0

16. Reserved X

17. Reserved X

18. Label Blank

19. Subscript 0

20. Seq. num. X

41
DATA FORM - ASCII - Directory Entry

Section

Entity Type(s): 124 (Forms 10,11,12)

ATTRIBUTE IGNORE VALID:

May be

defaulted to

VALID:

Non-Zero

Required

COMMENT

1. TYPE X

2. PD ptr. X

3. Structure X

4. Line Font X

5. Level X

6. View ptr. X

7. Matrix ptr. 0

8. Label ptr. X

9a. Blank S 00 If not blanked then

display coordinate system

in color indicated in DE

field 13

9b. Subord Sw 00 01 is used to stack

coordinate systems, 02 is used to group coordinate

systems

9c. Entity use X

9d. Hierarchy X

10. Seq. num. X

11. TYPE X

12. Line wt. X

13. Color 0

14. PD Count X

15. Form 0

16. Reserved X

17. Reserved X

18. Label Blank

19. Subscript 0

20. Seq. num. X

42
DATA FORM - ASCII - Directory Entry

Section

Entity Type(s): 200 Series except 212 and 214

ATTRIBUTE IGNORE VALID:

May be

defaulted to

VALID:

Non-Zero

Required

COMMENT

1. TYPE X

2. PD ptr. X

3. Structure X

4. Line Font X

5. Level 0

6. View ptr. 0

7. Matrix ptr. 0

8. Label ptr. 0

9a. Blank S 00

9b. Subord Sw 00

9c. Entity use X Must be 01

9d. Hierarchy 00

10. Seq. num. X

11. TYPE X

12. Line wt. 0

13. Color 0

14. PD Count X

15. Form 0

16. Reserved X

17. Reserved X

18. Label Blank

19. Subscript 0

20. Seq. num. X

43
DATA FORM - ASCII Directory Entry

Section

Entity Type(s): 212. 214 and 106 (Forms 20, 21, 31-40)

ATTRIBUTE IGNORE VALID:

May be

defaulted to

VALID:

Non-Zero

Required

COMMENT

1. TYPE X

2. PD ptr. X

3. Structure X

4. Line Font X Ignored for 106 (Forms 20, 21)

5. Level 0

6. View ptr. 0

7. Matrix ptr. 0

8. Label ptr. 0

9a. Blank S 00

9b. Subord Sw 00

9c. Entity use X Must be 01

9d. Hierarchy X

10. Seq. num. X

11. TYPE X

12. Line wt. 0

13. Color 0

14. PD Count X

15. Form 0 Non-zero required for 106

16. Reserved X

17. Reserved X

18. Label Blank

19. Subscript 0

20. Seq. num. X

44
DATA FORM - ASCII - Directory Entry

Section

Entity Type(s): 302, 306, 310

ATTRIBUTE IGNORE VALID:

May be

defaulted to

VALID:

Non-Zero

Required

COMMENT

1. TYPE X

2. PD ptr. X

3. Structure X

4. Line Font X

5. Level X

6. View ptr. X

7. Matrix ptr. X

8. Label ptr. X

9a. Blank S X

9b. Subord Sw 00 Must be 00

9c. Entity use X Must be 02

9d. Hierarchy X

10. Seq. num. X

11. TYPE X

12. Line wt. X

13. Color X

14. PD Count X

15. Form 0

16. Reserved X

17. Reserved X

18. Label Blank

19. Subscript 0

20. Seq. num. X

45
DATA FORM - ASCII - Directory Entry

Section

Entity Type(s): 304

ATTRIBUTE IGNORE VALID:

May be

defaulted to

VALID:

Non-Zero

Required

COMMENT

1. TYPE X

2. PD ptr. X

3. Structure X

4. Line Font X

5. Level X

6. View ptr. X

7. Matrix ptr. 0

8. Label ptr. X

9a. Blank S X

9b. Subord Sw 00 Must be 00

9c. Entity use X Must be 02

9d. Hierarchy X

10. Seq. num. X

11. TYPE X

12. Line wt. X

13. Color X

14. PD Count X

15. Form X

16. Reserved X

17. Reserved X

18. Label Blank

19. Subscript 0

20. Seq. num. X

46
DATA FORM - ASCII - Directory Entry

Section

Entity Type(s): 308, 320 Subfigure definition

ATTRIBUTE IGNORE VALID:

May be

defaulted to

VALID:

Non-Zero

Required

COMMENT

1. TYPE X

2. PD ptr. X

3. Structure X

4. Line. Font X Note 1

5. Level X Note 1

6. View ptr. X

7. Matrix ptr. 0

8. Label ptr. 0

9a. Blank S X

9b. Subord Sw 00 Must be 00

9c. Entity use X Must be 02

9d. Hierarchy 00

10. Seq. num. X

11. TYPE X

12. Line wt. 0 Note 1

13. Color 0 Note 1

14. PD Count X

15. Form 0

16. Reserved X

17. Reserved X

18. Label Blank

19. Subscript 0

20. Seq. num. X

Notes:

1. This field is ignored if the hierarchy value for the field is 01.

47
DATA FORM - ASCII - Directory Entry

Section

Entity Type(s): 312

ATTRIBUTE IGNORE VALID:

May be

defaulted to

VALID:

Non-Zero

Required

COMMENT

1. TYPE X

2. PD ptr. X

3. Structure X

4. Line Font X

5. Level X

6. View ptr. X

7. Matrix ptr. X

8. Label ptr. X

9a. Blank S X

9b. Subord Sw X Must be 02

9c. Entity use X Must be 02

9d. Hierarchy X Must be 01

10. Seq. num. X

11. TYPE X

12. Line wt. X

13. Color X

14. PD Count X

15. Form 0

16. Reserved X

17. Reserved X

18. Label Blank

19. Subscript 0

20. Seq. num. X

48
DATA FORM - ASCII Directory Entry

Section

Entity Type(s): 314

ATTRIBUTE IGNORE VALID:

May be

defaulted to

VALID:

Non-Zero

Required

COMMENT

1. TYPE X

2. PD ptr. X

3. Structure X

4. Line Font X

5. Level X

6. View ptr. X

7. Matrix ptr. X

8. Label ptr. X

9a. Blank S X

9b. Subord Sw 00 Must be 00

9c. Entity use X Must be 02

9d. Hierarchy X

10. Seq. num. X

11. TYPE X

12. Line wt. X

13. Color 0

14. PD Count X

15. Form 0

16. Reserved X

17. Reserved X

18. Label Blank

19. Subscript 0

20. Seq. num. X

49
DATA FORM - ASCII Directory Entry

Section

Entity Type(s): 402

ATTRIBUTE IGNORE VALID:

May be

defaulted to

VALID:

Non-Zero

Required

COMMENT

1. TYPE X

2. PD ptr. X

3. Structure X Ignored for form numbers

to 5000

4. Line Font X

5. Level X

6. View ptr. X

7. Matrix ptr. X

8. Label ptr. X

9a. Blank S X

9b. Subord Sw 00 00 required for Forms 3 &

4

9c. Entity use X

9d. Hierarchy X

10. Seq. num. X

11. TYPE X

12. Line wt. X

13. Color X

14. PD Count X

15. Form X

16. Reserved X

17. Reserved X

18. Label Blank

19. Subscript 0

20. Seq. num. X

50
DATA FORM - ASCII - Directory Entry

Section

Entity Type(s): 404

ATTRIBUTE IGNORE VALID:

May be

defaulted to

VALID: . Non-Zero

Required

COMMENT

1. TYPE X

2. PD ptr. X

3. Structure X

4. Line Font X

5. Level X

6. View ptr. X

7. Matrix ptr. X

8. Label ptr. X

9a. Blank S X

9b. Subord Sw 00 Must be independent

9c. Entity use X Must be 03

9d. Hierarchy X

10. Seq. num. X

11. TYPE X

12. Line wt. X

13. Color X

14. PD Count X

15. Form 0

16. Reserved X

17. Reserved X

18. Label Blank

19. Subscript 0

20. Seq. num. X

51
DATA FORM - ASCII Directory Entry

Section

Entity Type(s): 406

ATTRIBUTE IGNORE VALID:

May be

defaulted to

VALID:

Non-Zero

Required

COMMENT

1. TYPE X

2. PD ptr. X

3. Structure X

4. Line Font X

5. Level 0

6. View ptr. X

7. Matrix ptr. X

8. Label ptr. X

9a. Blank S X

9b. Subord Sw 00 See Note 1

9c. Entity use X

9d. Hierarchy X

10. Seq. num. X

11. TYPE X

12. Line wt. X

13. Color X

14. PD Count X

15. Form X

16. Reserved X

17. Reserved X

18. Label Blank

19. Subscript 0

20. Seq. num. X

Notes:

1. The setting for this field should be 02. The specification currently states a setting of 00 implies the property should be applied to all entities occurring at the same level.

52
DATA FORM - ASCII Directory Entry

Section

Entity Type(s): 408, 412, 414, 420

ATTRIBUTE IGNORE VALID:

May be

defaulted to

VALID:

Non-Zero

Required

COMMENT

1. TYPE X

2. PD ptr. X

3. Structure X

4. Line Font X

5. Level 0 See Note 1

6. View ptr. 0

7. Matrix ptr. 0

8. Label ptr. 0

9a. Blank S 00

9b. Subord Sw 00

9c. Entity use 00

9d. Hierarchy X

10. Seq. num. X

11. TYPE X

12. Line wt. X

13. Color X

14. PD Count X

15. Form 0

16. Reserved X

17. Reserved X

18. Label Blank

19. Subscript 0

20. Seq. num. X

Notes:

1. The specification currently states entities within a subfigure are displayed at the same level as the

instance.

53
DATA FORM - ASCII - Directory Entry

Section

Entity Type(s): 410

ATTRIBUTE IGNORE VALID:

May be

defaulted to

VALID:

Non-Zero

Required

COMMENT

1. TYPE X

2. PD ptr. X

3. Structure X

4. Line Font X

5. Level X

6. View ptr. X

7. Matrix ptr. 0

8. Label ptr. X

9a. Blank S X

9b. Subord Sw 00 Dependent if 404 points to

it. Independent if not.

9c. Entity use X Must be 03

9d. Hierarchy X

10. Seq. nura. X

11. TYPE X

12. Line wt. X

13. Color X

14. PD Count X

15. Form 0

16. Reserved X

17. Reserved X

18. Label Blank

19. Subscript 0

20. Seq. num. X

54
DATA FORM - ASCII - Parameter Data

Section

2.2.4. 4 Parameter Data Section

The parameter data section of the file contains the parameter data

associated with each entity. The following information is true for all parameter data.

2.2. 4. 4.1 Parameter data are placed in free format (see 2.2.3) with the first field

always containing the entity type number. Therefore, the entity type

number and a parameter delimiter (default is comma) precede parameter

one of each entity. The free format part of a parameter line ends in column 64. Column 65 shall contain a blank. Columns 66 through 72 on all parameter lines contain the sequence number of the first line in the

directory entry of the entity for which parameter data is being presented.

Column 73 of all lines in the parameter section shall contain the letter P

and columns 74 through 80 shall contain the sequence number (See 2.2.1).

2. 2. 4. 4.2 Two groups of parameters are defined at the end of the specified

parameters for each entity. The first group of parameters may contain

pointers to Associativity Instances, General Notes, and/or Text Template

entities. The second group of parameters may contain pointers to one or more properties. The pointers to associativity instances are "back

pointers" in that they point back from a member of an associativity

instance to the associativity instance. These pointers may be required by

the associativity definition.

If the given entity references associated text, a pointer to the General

Note may be included in the first group of pointers. If so, the indicated

General Note specifies the string constant and the indicated display

parameters.

If instead, the given entity contains a string constant to be displayed, a

pointer to a Text Template entity may be included in the first group of

pointers. The Text Template entities provide display parameters for text

supplied by the entity which points to the template.

55
DATA FORM - ASCII Parameter Data

Section

Either group of parameters, or both, may be empty or may be defaulted to no pointers.

When present, the pointers comprising these parameters are added after all the other specified (or defaulted) parameters, but ahead of the record

delimiter as follows:

Let NV = last parameter number

Index Name JX£e Description

NV+1 NA Integer Number of pointers to

NV+2 DE Pointer

Associativity

Entities

Associativity

Instances/Text

Instance/Text

NV+NA+1

NV+NA+2 NP Integer

Entity List

Number of Pointers to

NV+NA+3 DE Pointer

Properties

Property List

NV+NA+NP+2! . #

2. 2. 4. 4. 3 Any desired comment may be added after the record delimiter. Note that

additional lines may be used for this purpose by keeping the directory entry

pointer in columns 65-72 constant and include them in the count of

parameter lines for the entity (DE field 14). Figure 2-3 shows a parameter

data section.

56
DATA FORM ASCII Parameter Data

Section

PARAMETER DATA (PD) SECTION

1 64jlS 66 72 73 10

ENTITY TYPE NUMBER FOLLOWED BY PARAMETER DELIMITER

parameters Separated vy parameter delimiters

»

1

1

1

i

DC

>01NTER POOOOOOI

PARAMETERS SEPARATED BY PARAMETER DELIMITERS 1 RECORD DELIMETER • >0INTER >0000002

•

1 • •

1 • • • 1 • •

ENTITY TYPE NUMBER FOLLOWED BY PARAMETER DELIMITER

eio.

1

1

1

1 >oSniR W0000K

1

1

1

DC POINTER: THE SEQUENCE NUMBER OF THE FIRST DIRECTORY ENTRY LINE FOR THIS ENTITY

FIG. 2-3 PARAMETER DATA SECTION

57
DATA FORM - ASCII - Terminate

Section

2. 2. 4.

5

Terminate Section

There is only one line in the terminate section of the file. It is divided into

ten fields of eight columns each. The terminate section must be the last

line of the file. It has a "T" in column 73 and columns 74 through 80 contain

the sequence number with a value of one (1).

The fields on the terminate line contain the character representing the

section type and the last sequence number used in each of the previous

sections. The fields are defined below and shown in Figure 2-4.

FIELD COLUMNS SECTION

Start Section

Global Section

Directory Entry Section

Parameter Section

(not used)

Terminate Section

12

3

45-9

10

1-8

9-16

17-24

25-32

33-72

73-80

58
DATA FORM - ASCII - Terminat

Section

TERMINATE SECTION

I

1 8 9 16 17 24 25 32 33 40 41 48 49 56 57 64 63 72 73 86

1

S0000020

1

11

1

1

1

1 60000003 JD0000500

i

i

i

i

i

•

P000026I

i —mj i ua&y — T 0000001

J

6

FIG. 2-4 TERMINATE SECTION
THIS PAGE LEFT BLANK
DATA FORM - Compressed ASCII

2.3 Compressed ASCII Form

The format described here is intended to serve as an alternative to the

ASCII Form when the size of a file is a problem. The Compressed ASCII

Form is intended to be simply converted to and from the regular ASCII

Form. As an example of such a conversion, the National Bureau of

Standards has software available to convert from ASCII to Compressed

ASCII and from Compressed ASCII to regular ASCII (See Appendix G).

2.3. 1 File Structure

A single line shall precede the START section with the character "C" in

character position 73 to identify the file as compressed ASCII. The

START, GLOBAL and TERMINATE sections remain the same as the ASCII

Form, while the DE and PD sections are combined into a single DATA

section. The PD portion of the DATA section is written in free format in a manner similar to the present PD section. Each line is of variable length

and is to terminate before character position 65, thus assuring that

character position 65, if it existed (i.e., if the line is read into a fixed SO

character buffer) would always contain the blank character. The lines

corresponding to a single entity begin with one or more lines giving the

data presently contained in the DE record.

The "neo-DE" records begin with the letter "D", followed, without

intervening blanks, by an integer equal to the present sequence number of

the first DE record. See Figure 2-5. The D< sequence number^ group of

characters is followed by one or more DE field specifiers. The DE field

specifier consists of the symbol (commercial at) followed by an integer

giving the DE field being specified. The (5 field number group is followed by a character sequence consisting of the symbol (underline),

followed by the value of the field.

All DE field numbers remain the same as with the present DE record.

Fields 2, 10, 11, and 20 are not specified, as they are either redundant or meaningless in the Compressed ASCII form. When several DE

61
DATA FORM - Compressed ASCII

fields are being specified, additional lines can be used. The sequence of

field specifiers must be broken only between complete specifiers, thus

assuring that new records will begin with the symbol "(d".

Field values will be specified only when they change. Thus, a field retains

its value from entity to entity unless it is changed, and only the first entity

in a file is assured of containing a complete set of fields and values. No

separation mark is used between (cKfield number ]S^value group^ but the

DE field specifier record(s) end with a record delimiter (default

80! START SECTION

GLOBAL SECTION

012364-2... ADDITIONAL FIELD DESCRIPTORS...

...USING AS MANY LINES OF UP TO 72 CHAR.

...EACH t

...PD RECORD BELONGING TO DE *123

...ON LINES UP TO 64 CHAR

0125 ....

...PD RECORD ... TERMINATE SECTION

NOTE: DEFAULT RECORD DELIMITER ASSUMED

FIGURE 2-5 COMPRESSED ASCII FORM

The PD records remain the same as in the ASCII Form with the exception

that they terminate at the end of parameter data (i.e., before character

position 65).

62
DATA FORM - Binary

2.4 Binary Form

The format defined in Section 2.2, referred to as the ASCII Form, has

80 character fixed length record lines. This section describes a bit

stream binary representation of data which may be used as an

alternative format to the ASCII Form.

This data is transportable by user selected communication protocols

with the data treated as "transparent" or bit stream data. All entity

parameterizations and data organization are otherwise identical to the

ASCII Form.

2.4.1 Constants. The following constants need to be represented in the

Binary Form:

o integer numbers

o real numbers

o string constants

o pointers o language constants

63
DATA FORM - Binary

A control byte will precede each value or set of values of the same

type, unless otherwise specified. The control byte will specify the

format of the following value or set of values, the quantity of

subsequent values with that format, and whether values other than the

initial value following the control byte are present. If the control byte

indicates that values subsequent to the initial value of the set are

absent, all subsequent values, up to the quantity indicated are assumed

to have the same value as the initial value following the control byte.

The repetition portion of the control byte is unsigned and biased by 1 so that the true quantity of numbers to which the repetition field applies

is one more than the unsigned value of the field.

The format of the control byte is as shown in Figure 2-6.

2.4. 1.1 Integer Numbers.

The structure of an integer number shall be a sign bit followed by a

two's complement integer of length i-1 as shown in Figure 2-7.

Two lengths, i, of integer data can be selected by the system which

generates the file.

The length of single precision data is i and the length of double

precision data is i^ , defined in section 2. 4. 2.1.

2.4. 1.2 Real Numbers.

The structure of a real number shall be a sign bit followed by a biased

exponent value of NX bits which is a power of 2 and a binary fraction

of NF bits. (NX and NF are defined in section 2.4.2. 1) The value of the

number is the sign applied to the fractional part multiplied by two

raised to the power specified by the exponent part. The sign field

consists of one bit. A sign of 0 indicates a positive number and a sign

of 1 indicates a negative number. The exponent field consists of NX

bits and is interpreted as an unsigned integer, BX, often referred to as the biased exponent. The value of the exponent is its unbiased value X

which is obtained by deducting the bias B=2**(NX-1).

64
CONTROL

BYTE

FORMAT:

DATA FORM - Binary

X c/) 2 £

S3 s! 2 I

a.

CO

yj

COUJ

er CO 3 CL. H* <>©

UJ»— >

—1<<_>

XuX

rc <

UJ CO>-

©

a

a.

X h* UJ

UJcc

a. CO3

UJ

H

ll

X 1 UJ o < C9 K CO CO

UJ3 ©

UJ

CO UJ3

h- _J co < < 0=3

u_ UJ © a 25 3

UJ c=J h X <

cou

© > x UJ

ess a. -

u.

X

© -J UJ UL 3

>- <

-J u_ U- z «J o Ul © < a

u> u.

xUJ u.

m*s> esX o r-t* 3 o H 0 W* n

•• < z 1— v* o <

CL

X H- tr©

u_

UJ

aUla:

1- 1- z®E2» z © © CL Cl © ©

e=» z z»BZ» H- s=

x

x < < Ul Ul © © © © _J -J

UJ Ul LL LL

»- J— z z Z Z © o «=3 SsS X X © CO

«M9

©©

uu

© z z UJ UJ Z

UJ Ul

XX -J -J a. X

X

X h® UJ Ul UJ Ul UJ CO mJ _J -1 1- © ea © 03 z h z 3 z 3 X O e=3 O o Ul CO o CO a a. 1-

U- U. u.

X LL LL

H CN cn in VO n It R li 1 a

65

FIGURE

2-6

FORMAT

OF

CONTROL

BYTE
DATA FORM Binary

66
DATA FORM - Binary

The fraction field consists of NF bits interpreted as the low order bits

of a normalized (NF+l)-bit fraction part, F. The fraction lies between

0.5 (inclusive) and 1.0 (exclusive). Since the most significant bit of a normalized fraction is always 1 it is not explicitly represented.

Numbers with a non-zero biased exponent have a value given by:

(1)sign*

2(bx-b)*f

The structure of a real number is shown in Figure 2-8.

Two lengths of real data can be selected by specifying the length of

each exponent (NX) and the length of each fractional portion (NF).

2. 4. 1 .3 String Constants.

Following the control byte will be a character count with a length of i g

, defined in section 2. 4. 2.1. Where the character count exceeds the

capability of an i g length integer, the string is broken up into substrings.

In order to indicate that another substring follows the current string, a negative character count is used. The number of characters in the

substring is the absolute value of the character count. A positive

character count indicates the last substring.

67
DATA FORM - BinaryOz

I-<o

inXI

I-oz

Hi o

Hia

=3

-JOz

CO

CO

ffl o x©

UJa.O

LUI CL

=32<

CO

O

cr

como

ccHiN

U_OD<

CL

UJX

Xz+

cr

UJqq2z

CL <

CCo

Li. LU>

hCC

CL

CC

LUm2<

LU

cc

COI CM

LU

CC

Z)o

Li68
DATA FORM - Binary

The structure of the string constant is shown in Figure 2-9.

2.4. 1.4 Pointers.

The structure of a pointer shall be a 32 bit integer. The pointer shall

contain the relative byte position of the entity byte count of the DE or PD entity to which it is pointing. A pointer to the first DE entity will

have a value of 1. A pointer to the second DE entity will have a value

equal to the number of bytes of the first DE entity plus one. A pointer

to the first PD entity will have a value of 1. Pointers with values of zero or negative are not actual pointers but may have a default

meaning depending upon the context. For example, a defining matrix

value of zero would imply that the identity rotation matrix and zero

translation vector are used. This case might also be handled by using

the control byte, instead, to indicate a default value.

2.4.1 .5 Language Primitives. Language primitives are the string constants of

the MACRO definition entity which, in the ASCII Form, are not

preceded by nH and are terminated with a record delimiter. In Binary

Form the format of language primitives will be identical to string

constants. Each language primitive (MACRO statement) will be an

individual string constant.

2.4.2 File Structure. The general file structure is as shown in Figure 2-10

and is comprised of the following six sections:

o Binary information section o Start section o Global section o Directory entry section o Parameter Data section o Terminate section

Following each section is zero, one or many 8-bit null padding characters. These characters do not belong to the section and have no meaning. They are provided to assist the creator of a file with

69
DATA FORM - Binary

*j

§

u oe

«e <

O —

i<

a

U

o

1 Cl

70

FIGURE

2-9

STRING

CONSTANT

PRIMITIVE

FORMAT
DATA FORM - Binary

BINARY INFORMATION SECTION

START SECTION

GLOBAL SECTION

DIRECTORY ENTRY SECTION

PARAMETER SECTION

TERMINATE SECTION

FIGURE 2-10 BINARY GENERAL FILE STRUCTURE

71
DATA FORM - Binary

physical system limitations such as word or sector boundaries.

Following the terminate section of the file shall be zero, one, or many

null padding characters followed by an 8-bit end of information

designator, the ASCII letter E. Any information following the letter E

shall be ignored.

2.4.2. 1 Binary Information Section. The format of the binary information

section is as shown in Figure 2-11. It is comprised of the following data

items, all of which are integers unless otherwise specified.

o Binary information section identifier consisting of the ASCII

letter B. o Binary information section byte count. This byte count

excludes the 5 bytes required for the section identifier and

section byte count. This byte count also excludes any null padding characters. The value of this byte count will be 75. o Length i of single length integer primitives, o Length i^ of double length integer primitives, o Length NX

g of exponent of single precision real primitives, o Length NF

g of binary fraction of single precision real

primitives. o Length NX^ of exponent of double precision real primitives, o Length NF^ of binary fraction of double precision real

primitives, o ASCII letter B. o Binary information section displacement. This is the byte count

of the total length of the binary information section including

all null padding characters. This length is the actual length

from the initial B of the binary information section up to but

not including the S of the start section, o ASCII letter S. o Start section displacement. This is the byte count of the total

length of the start section including all control bytes and null padding characters. This length is the actual length from the

initial S of the start section up to but not including the G of the

72
DATA FORM - Binary

1 n

tkX

O

im

V-«

> a

X

x

4 O

09

tV)-

a

c»

j «9

I&. as

4

IN

t5

A

*» XX

no f%

[=a

r

a

m

*

a

H-A

a

>

m

4

J

0

1

•»h-0

9

99-

A

n

P

sfif SJhu

sga-t * m

m

4

j1

•

BITS |

r^jl

Q

o1 1

1

^H

u ine

«eIN

s o* S £lli g»-o 3 u <

O «U T1 w «#•m

to

Ho* K .W

< •- « rM Uio *3

= <2!

e2»-!

;cc(j

k °uj

*4

©

ai

NO P

•

BITS n

col

eo

•

BLANKS OR ASCII

ZEROES

4 ESm

NO

1

L *>U4 A ^

9- >* — A

A

5** 0

as»

' *

a

\

t 8

IA _ Ui -r* >

“_l $ • O

u n

' as %

O

***\%

4 NOm

1

1 £

M H

» (U «

*" 5 0

r 5

TERMINATION SECTION CiSPLACEMENT

4 minn

<

> i

M O

3 £

as “

IN X

« oc<

> 5

*-

4 NO

ONA

1

1 •

•* Ui = p

m x

M

PARAMETER DATA SECTION DISPLACEMENT

4 03IN

*

‘ s

M £ £ -

: s

« •

A NO

an«N

i mA

73

FIGURE

2-11

FORMAT

OF

BINARY

INFORMATION

SECTION
DATA FORM - Binary

global section, o ASCII letter G.

o Global section displacement. This is the byte count of the total

length of the global section including all control bytes and null padding characters. This length is the actual length from the

initial G of the global section up to but not including the D of

the directory entry section, o ASCII letter D.

o Directory entry section displacement. This is the byte count of

the total length of the descriptive entity section including all control bytes and null padding characters. The length is the

actual length from the initial D of the directory entry section

up to but not including the P of the parameter data section, o ASCII letter P. o Parameter data section displacement. This is the byte count of

the total length of the parameter data section including all control bytes and null padding characters. This length is the

actual length from the initial P of the parameter data section

up to but not including the T of the terminate section, o ASCII letter T. o Terminate section displacement. This is the byte count of the

total length of the terminate section including all null padding

characters. This length is the actual length from the initial T

of the terminate section up to but not including the letter E of

the end of information designator,

o 31 unassigned bytes, o ASCII letter B. o 6 ASCII blanks or zeroes,

o ASCII character 1.

No control bytes are applied to this section. Thus the characters in the

equivalent of columns 73 through 80 of the binary information section are

similar in format to the section identification of the ASCII Form and can

be used to determine if a file is ASCII or binary. If the file contains an S in column 73 of its first 80 bytes, it is ASCII (or C if compressed ASCII). If it contains a B, it is binary.

74
DATA FORM - Binary

2. 4. 2. 2 Start Section. The format of the start section is as shown in Figure 2-12.

It is comprised of the following data items:

o A start section identifier consisting of the ASCII letter S o Byte count for the start section. The byte count excludes the 5 bytes required for the start section identifier and section byte

count. This byte count also excludes any null padding characters. o One or more language or text primitives which are logically

equivalent to columns 1 through 72 of the ASCII Form. There is no required physical correspondence between the ASCII Form

and language/text primitives. One language/text primitive may

contain the equivalent of several complete or partial ASCII

records. Carriage return characters may be embedded in the

language/text primitives. Control bytes only apply to the

language and text primitives. No control bytes precede the

section identifier and byte count.

2. 4. 2. 3 Global Section. The format of the global section is as shown in Figure 2-

13. The global section is comprised of the following data items:

o Global section identifier consisting of the ASCII letter G

o Global section byte count. This byte count excludes the 5 bytes

required for the global section identifier and the section byte

count. This byte count also excludes any null padding characters. o 24 global parameters.

Control bytes apply only to the 24 global parameters.

The global parameters have the same sequence and meaning as the ASCII

Form global parameters with the exception that global parameters 1 (parameter delimiter character), 2 (record delimiter), 7 (number of bits for

integer representation), 8 (single precision magnitude), 9 (single precision

significance), 10 (double precision magnitude), and 11 (double precision

significance) shall be ignored in Binary Form. The binary information

section shall supersede these global parameters.

75
THE

FORMAT

OF

THE

LANGUAGE/TEXT

PRIMITIVES

IS

AS

SHOWN

IN

FIGURE

DATA FORM - Binary

76
DATA FORM - Binary

CC

UJ—

UJ ©

VsJ

iVNj

Ui

< £ «q©

«j©

02 d N= « £ . og

a.

«o

00

<N

CO

CQ

©•— I— H* 2: © 3

UJ o CO u

< 1“ ® >

© CQ J

©

©

©

Ui

8“>

SO©

ce©©

UJ>

<X

o©

©©

-1

UJu.

UJ

COUJX

DC

o

LL

o

UJ

CO

<

DO

O

-J0

CO

1 CM

UJ

DC

D

0

LL

77
DATA FORM — Binary

2.4. 2.4 Directory Entry Section. The format of the directory entry section is as shown in Figure 2-14. The directory entry section is comprised of the

following data items:

o Directory entry section identifier consisting of the ASCII letter

D

o Directory entry section byte count. This byte count excludes

the 5 bytes required for the section identifier and section byte

count. This byte count also excludes any null padding characters. o For each directory entry, the following 17 data fields are

present:

entity byte count, which is the length in bytes, including

control bytes, of the subsequent 16 data fields,

entity type

parameter data pointer structure

line font number or pointer

level number or pointer

view pointer

transformation matrix pointer

label display associativity pointer

status number

line weight

color number or pointer

form number

reserved field 1 reserved field 2

entity label

entity subscript

r

78
DATA FORM - Binary

SNKTs.

d

rj

co

BITS

SECTION

BYTE

COUNT

*

A L

IS) CD

*—CO o

1 r

V.

R -•

nt £

EC

UJ

EC ffl o 2

U- 3

Z

EC

EC UJ o CD -J 5 O 3 o Z

iju se z to —J (UJ

ex: *— o •—

o«£UJ

O

z

o

D

too

_l

UJ

UJCO

UJx

t0)

UJH

>-m

O

£E

I-Z

o

o

UJ>

<

x

79

FIGURE

2-14

FORMAT

OF

DE

SUBRECORD
o

DATA FORM - Binary

Control bytes apply only to the last 16 data fields.

The directory entry data fields, except for the entity byte count, are

identical to and have the same sequence as fields in the ASCII Form.

Within a single file, the length of DE record for each entity (in bytes) shall be consistent. If in the future additional fields are required, it is preferable to increase the number of fields for each directory entry and

add any new fields subsequent to existing fields.

2A.2.5 Parameter Section. The format of the parameter data section is as .shown

in Figure 2-15. The parameter data section is comprised of the following

data items:

o Parameter data section identifier consisting of the ASCII letter

P

o Parameter data section byte count. This byte count excludes

the 5 bytes required for the section identifier and section byte

count. This byte count also excludes any null padding characters. o For each parameter data entity, the following data fields are

required:

entity byte count, which is composed of the lengths,

including control bytes, of all subsequent data fields for

this entity,

entity type

directory entry pointer (relative to directory entry

section)

parameter data

Control bytes apply only to the entity type, directory entry pointer and

parameter data fields.

The parameter data entity fields, except for the entity byte count, are

identical to and have the same sequence as the the ASCII Form.

80
DATA FORM - Binary

4

1

PARAMETER

DATA

80UJ“»*A

«JOK

H-X

©

u

UJ>

<

X

H©

©6

@0a

_j

UJu.

©

W

t5 DIRECTORY ENTRY POINTER

as

to

cn ENTITY

TYPE

(N

to

(——

to

i r

ENTITY

BYTE

COUNT

•

UJ

toUJX»- •

Vi ,

-J

*— v

Ui X —

Q. OH O HUJ O < Z K U. Ui UJ

81

FIGURE

2-15

FORMAT

OF

PARAMETER

SECTION
DATA FORM - Binary

2. 4. 2. 6 Terminate Section. The format of the terminate section is as shown in Figure 2-16. The terminate section is comprised of the following data

items:

o Terminate section identifier consisting of the ASCII letter T

o Terminate section byte count. This byte count excludes the 5 bytes required for the section identifier and section byte count.

This byte count also excludes any null padding characters, o ASCII letter B

o Binary identification section byte count, including the section

identifier, and section byte count, but excluding any null padding characters, o ASCII letter S o Start section byte count, including the section identifier,

section byte count, and all control bytes but excluding any null padding characters,

o ASCII letter G

o Global section byte count, including the section identifier,

section byte count, and all control bytes but excluding any null padding characters,

o ASCII letter D

o Directory entry section byte count, including the section identifier, section byte count, and all control bytes but excluding any

null padding characters,

o ASCII letter P

o Parameter data section byte count, including the section identifier, section byte count, and all control bytes but excluding

any null padding characters.

The terminate section has no control bytes applied to any of its data.

82
DATA FORM - Binary

^ r

' VW

co !

fia

•o

m

*

1/5 h-5

r

START SECTION

byte

COUNT

CO

cn»—0

•

co

04m

co

t—0

BINARY

SECTION

BYTE

COUNT.

o

tnh~0

r

• 0

04n

t/t h~0

SECTION

BYTE

COUNT*

OB

a

to

*—0

' r

•

»-

UJ>

<

©

m uj

a -

_j >-

UJ 0

©

UJ 0£ m H*

uj s X o

u

83

FIGURE

2-16

FORMAT

OF

TERMINATE

SECTION

DATA FORM - Specific File

Structures

2.5 Specific File Structures

Individual entities of the file structure are described in Sections 3 and 4

of this document. Complete files of these entities must be structured

uniformly to convey specialized information between applications.

Some of the ways in which those entities tie together to form

relationships are described in this Section.

2.5.1 Subfigures

The concept of subfigures is supported by defining a collection of

entities once and then instancing that collection multiple times in the

model at various locations, orientations, and scales. The entity use flag

defines how the entity will be used in the model. The structure consists

of a Subfigure Definition Entity (type 308) which points to a collection

of entities (see Figure 2-17). One or more subfigure instance entities

may point to the subfigure definition entity and specify an X,Y,Z

location and scale factor. Rotation of the instance is specified by

having the subfigure instance point to a transformation matrix entity.

Two types of subfigure definitions and four types of subfigure instances

are defined. The Subfigure Definition Entity can be instanced: (1) individually by the Singular Subfigure Instance Entity, (2) as a rectangular grid of instances by the Rectangular Array Subfigure

Instance Entity or, (3) as a circularly located set of instances by the

Circular Array Subfigure Instance Entity. Items which have locations

specified for logical connections (represented by one or more Connect

Point Entities) in their subfigure definitions, and thus instances, or which require independent scale factors in the X,Y, and Z axes shall be

defined by a Network Subfigure Definition Entity and (4) instanced by

the Network Subfigure Instance Entity (see Section 2.5.2 and Figure 2-

18).

85
DATA FORM - Specific File

Structures

'I

)

86

SUBFIGURE

STRUCTURES

FIGURE

2-17
DATA FORM - Specific File

Structures

87

GENERAL

CONNECTIVITY

POINTER

DIAGRAM
DATA FORM - Specific File

Structures

2.5.2 Connectivity

The following file structure shall be used to define logical (and the

location for physical) connections between objects.

A formed connection between two or more objects requires the data to represent the following:

1. the exact location of each connection point

2. the flow path formed and its identification (if any)

3. the physical connection between the objects (if any)

These objects may include electrical or mechanical components such as

transistors, pipes and valves, and air conditioning ductwork. Each

connection formed defines a flow path between the objects, allowing a

fluid (electricity, water, or air) to flow from one object to another.

The Network Subfigure (Definition and Instance) entities are used to represent the objects to be connected. The Connect Point Entity is used to represent the exact location of connection. The term "link" will

refer tD the logical representation of the flow path (signal) formed, and

"flow-name" will refer to the flow path identifier. The term "join" will refer to the file entity or entities which represent the physical

connection (geometries between the items).

2.5.2. 1 Connectivity Entities

The entities used to implement connectivity include the Network

Subfigure Definition (type 320) and Network Subfigure Instance (type

420) entities, the Flow Associativity (type 402 form 18), the Connect

Point Entity (type 132), and the Text Display Template (type 312;

absolute = form 0, incremental = form 1).

2. 5. 2. 2 Entity Relationships

A flow path (signal) may be formed between items by a link which

references the items' connect points (entities) to be related. This

88
DATA FORM - Specific File

Structures

creates an associativity among the connect points and thus the entities

connected. The flow-name may be used to uniquely identify the

particular signal formed. The join may be used to provide a graphical

representation of the flow path. In electrical applications the join will

be represented by geometric entities such as line, arc, subfigure, copious

data, etc. In a piping application, an example of a join represented

might be the section of pipe between a valve and a tank. The logical

constructs (link and flow-name) shall be implemented by the Flow

Associativity Entity which in turn identifies (by pointer) the entities

which form the join.

In electrical applications, for example, the items to be connected are components (i.e., resistor, 16-pin dual in-line package, etc.), or integrated circuit cells, represented and instanced by Network

Subfigures. Each pin (or signal port) is a potential connection point in a flow path, thus each Network Subfigure has a Connect Point for each

pin (or port). When such a subfigure is instanced, its connect points

must also be instanced. An instanced Connect Point, when added to a flow path is different from its definition which shall not be a member

of any flow path. See Figure 2-18 for the basic entity relationships.

For more information see Appendix B.

2. 5. 2. 3 Information Display

The Network Subfigures, representing electrical components for

example, often contain text describing the component and its pins. The

Text Display Template allows text, embedded in another entity to be

displayed without redundant specification of the text string. The Text

Display Template may be used to display reference designators and pin

numbers. The absolute form, within a network subfigure, is recommended for the reference designator text. Each instance of the

subfigure need only supply the text string. The pin number can be

represented in the incremental form. All the pin numbers on a given

side of a package outline having the same X, Y, and Z offsets relative

to the pin whose number is to be displayed may use the same Text

Display Template definition.

89
DATA FORM -- Specific File

Structures

2.5.2.

4

Additional Considerations

The situation is exactly the same for both logical and physical product

representations. The only differences arise in the subfigure and join

entities used. One file may contain both schematic and physical

representations of a product. The Flow Associativity Entity contains a type flag to indicate the connection type (logical or physical). In this case, one Flow Associativity would represent the logical connection and

a second the physical connection. The two associativities would be

related by the pointers provided in the Flow Associativity.

2.5.3 MACROS

A MACRO capability is provided for defining new entities in terms of

other entities. See Section 4.3.6. Two specific applications for the

MACRO capability are parametric designs and standard parts. The

structure consists of MACRO definition entities which are pointed to by

MACRO instance entities as shown in Figure 2-19. Each MACRO

definition is assigned a unique MACRO entity type number. MACRO

instance entities use this number as their entity type number. MACRO

instance entities also use the third field of their directory entry to

point to the directory entry of the MACRO definition (or to an external

reference entity which points to a library file containing the MACRO

definition).

2.5.4 External Reference Linkage

Linkages between entities can occur not only within a file, but also

between entities in different files. Two entities shall be used in a referencing file to establish this linkage: the External Reference Entity

(Type 416) which provides the actual linkage to the referenced file, and

the External Reference File List Property Entity (Type 406 Form 12)

which provides a list of the names of all the files referenced. Further,

only directly referenced files shall be in this property's parameter list. Each file name listed in the parameter data of this property must

match the name in the fourth global parameter of a referenced file.

90
DATA FORM - Specific File

Structures

DIRECTORY ENTRY SECTION

MACRO DEFINITION

MACRO INSTANCE

MACRO INSTANCE

MACRO DEFINITION

MACRO INSTANCE

MACRO INSTANCE

MACRO DEFINITION / INSTANCE STRUCTURE

FIGURE 2-19

91
DATA FORM - Specific File

Structures

An External Reference File Index associativity (type 402 form 12) is required in the referenced file when the type 416 Form 0 or 2 is used

(i.e., more than one referenced entity in the referenced file).

This associativity provides a directory to the referenced entities within

its file, and both relate a symbolic name to the directory entry of an

entity within the file (see Figure 2-20). All symbolic names used within a set of files linked by references must be unique. Definitions may be

nested, and a symbolic name used need be unique only on the nesting

level on which it is used.

Because of the intricacy of the linkages, an example follows (refer to Figure 2-20). Consider a file containing a subfigure instance entity

(type 408). The first item in its parameter data record is a pointer to the subfigure definition entry in the DE section of the file. In the case

that the subfigure definition entity (type 308) is to be contained in a

library file, this first parameter is a pointer to an external reference

entity (type 416). The external reference entity so referenced will have

in its parameter data record the name of the file which is to contain

the definition and the symbolic name of the definition itself. The file name is the fourth global parameter in the referenced file. The

symbolic name is a string which identifies the appropriate referenced

definition.

In the case of a library file which contains several definitions, each of

which are expected to be referenced by other files, the External

Reference Associativity (type 402 form 12) provides a "table of

contents" of the available definitions in the file. The parameter data

record of this associativity contains pairs of data: the symbolic name

associated with the definition (the same one used in the Type 416

entity's parameter data record), and a pointer to the directory entry

record which contains the desired definition.

92
2.5.5

DATA FORM - Specific File

Structures

In the case that the entire external file is to be included (i.e., a supersubfigure), Form 1 of the Type 416 entity is used which does not contain a symbolic name in the parameter data record. In a similar manner, the

referenced file does not contain an associativity Type 402 Form 2 or 12

entity; it is unneeded since the entire file is to be used.

In either case, the External Reference File Index Property (type 406

Form 12) will be found in the referencing file. The parameter data

record contains a simple list of the file names of the various external

files referenced by this file. Once again, the file name used is that in the fourth global parameter of the referenced file. Note that this list contains only those file names that are directly referenced; it gives no

information about files which may be referenced in turn by those files

used by this file.

A limitation of external referencing is that the backpointers (in the

"backpointers to associativities" addition to an entity's parameters)

cannot be used. If a pointer is required in each direction, separate

external reference mechanisms must exist in each file (e.g., the double

linkage between files A and B in Figure 2-20).

A preprocessor implementor should use the external logical reference

mechanism with care because of the burden placed on the

postprocessor.

Drawings and Views

This Specification provides a mechanism for associating models and

drawings so that there is consistency between them. The mechanism is based on the existing practices of some CAD/CAM graphic systems to define the views of a part on a drawing in terms of a single 3- dimensional (3-D) model.

The Drawing Entity (type 404) specifies a drawing of a given size within

a special drawing space coordinate system. This entity can refer to one

or more View entities (type 410) which will specify the projection from

93
DATA FORM Specific File

Structures

94

EXTERNAL

LINKAGES

FIGURE

2-20
2.5.6

DATA FORM - Specific File

Structures

3-D model space to the 2-D drawing space. Annotation entities such as dimensioning can be defined directly in the drawing coordinate system,

or can be defined in the 3-D model space and then be included in

individual views. More than one drawing entity may be included in a

file.

In addition to being used in conjunction with the Drawing entity, the

view-specific display of parts of the model can be used to communicate

hidden lines, phantom lines, etc.

Graphic systems which do not have the ability to define drawing and

views of models in this manner are not required to preprocess this

construct into a file, but all systems with postprocessors must be able

to process the drawing and view entities in received files.

Finite Element Modeling

This Section defines the entities and their relationships (pointers)

required to support the Finite Element Modeling (FEM) application and

to display results of analysis on those systems which support finite

element analysis postprocessing.

The entities available for exchanging FEM data are illustrated in Figures 2-21 and 2-22. The left side of Figure 2-21 illustrates the

relationships between the entities that define the model's parametric

attributes. The right side illustrates the addition of the analysis

results. Figure 2-22 illustrates the FEM entities used to define an example beam structure with accompanying material properties, a load,

and a constraint. The entities defined in support of such analysis are

the Element, Node, Load/Constraint, Tabular Data Property, and Nodal

Displacement and Rotation.

Element (type 136) defines a finite element to be used in the finite

element model. Several finite elements are defined in the

Specification. Examples of an element are: BEAM, CTRIA, and DAMP.

Specifically, the element entity specifies the topology type, number of

95
DATA FORM - Specific File

Structures

96

FIGURE

2-21

FINITE

ELEMENT

MODELING

FILE

STRUCTURE
DATA FORM - Specific File

Structures

( 212) ( 212 )

FINITE ELEMENT MODELING LOGICAL STRUCTURE

FIGURE 2-22

97
DATA FORM - Specific File

Structures

nodes, and the element type name. Pointers locate the defining nodes

and the material properties of the element. The connectivity of the

nodes is implied in the order of the contained pointers and topology

type.

Node (type 134) defines the grid points or nodes of the element. It contains the spatial values that define the node and a pointer to the

coordinate system upon which it is defined.

Load/Constraint (type 418) is an entity that points to a node. It defines

either a load or a constraint as applied to that node. It also contains a

pointer to general note entities that define the load case. Property

pointers point to the tabular data entity that contains the values of the

load or constraint vector.

Tabular Data Property (type 406 form 11) contains the material

property data of the elements and the load/constraint data as required.

Nodal Displacement and Rotation Entity (type 138) is used to contain

the analysis results in the form of incremental variations in node

position.

2.5.7 Multiple Transformation Entities

There are only two cases in which entities can be operated on by

multiple transformation entities. The first is the explicit case in which

an entity points to a transformation entity through its directory entry

field 7, and that transformation entity, in turn, points to an additional

transformation entity through its directory entry field 7. This structure

is illustrated in Figure 2-23a.

The other case is an implicit one in which two entities are in a parent/child relationship, and each points to a transformation entity

through its respective directory entry field 7. A parent/child

relationship occurs when one entity (the parent) is pointing to another

entity (the child). This structure is illustrated in Figure 2-23b.

98
DATA FORM - Specific File

Structures

DE FIELD 7 DE FIELD 7

ENTITY TRANSFORMATION

MATRIX

TRANSFORMATION

MATRIX

o) EXPLICIT CASE

DE FIELD 7

CHILD TRANSFORMATION

ENTITY MATRIX

b) PARENT-CHILD CASE

MULTIPLE TRANSFORMATION CASES

FIGURE 2-23

99
DATA FORM - Specific File

Structures

In the cases illustrated by Figure 2-23 the points represented by entity

XXX are operated upon by matrix 2 and from that point on are transformed like the points in entity YYY, using matrix 1.

A parent/child relationship between entities may also be created with

a Single Parent Associativity instance entity (type 402, Form 9).

When the specific parent/child relationships shown in Table 2-4 occur

the implicit relation rule shall apply. Each of the relationships in Table 2-4 ordinarily results in the subordinate entity switch of the

child entity being set to 01 (physically dependent). The exception is the case in which a preprocessor wishes to actually instance the child

entity. In this case the child's subordinate entity switch is set to 02

(logically dependent), and the matrix pointed to by the parent has no

effect on the location of the child (see Section 2. 2. 4. 3.9. 2).

100
DATA FORM - Specific File

Structures

TABLE 2-4

PHYSICAL PARENT/CHILD RELATIONSHIPS

Parent

Composite Curve

Plane

Point

Ruled Surface

Flash

Surface of Revolution

Tabulated Cylinder

Offset Curve

Offset Surface

Trimmed Surface

Angular Dimension

Diameter Dimension

Flag Note

General Label

Linear Dimension

Ordinate Dimension

Point Dimension

Radius Dimension

General Symbol

Sectioned Area

Entity Label Display

Connect Point

Drawing

Subfigure Definition

Network Subfigure

Definition

Nodal Display and Rotation

any entity with entity use flag

=00 or 01

Child

all constituents,

bounding curve

display symbol

rail curves

defining entity

axis, generatrix

directrix

base curve

surface

surface

all subordinate entities

all subordinate entities

all subordinate entities

all subordinate entities

all subordinate entities

all subordinate entities

all subordinate entities

all subordinate entities

all subordinate entities

all boundary curves

all leaders

display symbol, Text Display

Templates

all annotation entities

all associated entities

all associated entities,

Text Display Templates

and Connect Points

all General Notes and Nodes

all General Notes in text

pointer field

101
THIS PAGE LEFT BLANK
GEOMETRY - General

3 GEOMETRY

3. 1 General

This section gives information concerning the geometry entity types

available to be used in the entity-based product definition file. Descriptions of the various directory entry fields were given yi Section

2.2.4. 3. The meanings of these fields remain the same across all entities.

In this section those entities making extended use of field 15 in the

directory entry (Form Number) are indicated and the various options are

listed. The parameter data record for each entity is also described in this

section. The fields for this record vary from entity to entity.

3.1.1 Coordinate Systems.

This section introduces a model space concept and a definition space

concept. Model space is three-dimensional Euclidean space, the space in

which the "model" (or product) being represented resides. The model space

X, Y, Z coordinate system is a right-handed Cartesian coordinate system.

It is fixed relative to the model.

Definition space is also three-dimensional Euclidean space, but has its own

right-handed Cartesian XT, YT, ZT coordinate system. In contrast to model space where a single fixed coordinate system exists, the definition

space coordinate system may vary from entity to entity. The origin of a

definition space coordinate system may be any point in model space, and

the orientation may be arbitrary with respect to model space. It is assumed that the unit of length is always the same in both the model space

and the definition space coordinate systems.

103
GEOMETRY - General

The definition space concept allows the use of a temporary coordinate

system in positioning certain geometric entities into model space. This

concept plays a simplifying role that is most apparent in connection with

those entities which can be contained within a single plane. Use of

definition space entails initially describing an entity in definition space,

and then converting this to a model space description. Thus, an orthogonal

matrix and a translation vector are used to generate model space

coordinates from definition space coordinates. The orthogonal matrix

used for this purpose is called the defining matrix; both it and the

translation vector are treated within the Transformation Matrix entity.

The value of the determinant of an orthogonal matrix is always plus or minus one. In case the determinant is one, there are two equivalent points

of view that can be taken concerning how the geometric entity is related

to model space from its definition space description. In order to simplify

the discussion of these that follows, the translation vector is assumed to be

the zero vector. This implies that the origin of the definition space

coordinate system coincides with the origin in the model space coordinate

system.

The first point of view imagines that the two coordinate systems are

initially coincident (that is, X axis to XT axis, etc.) but that the XT, YT,

ZT coordinate frame is free to rotate relative to the X, Y, Z frame. The

geometry entity is then considered to be defined relative to the XT, YT,

ZT frame, and the defining matrix then rotates this frame, geometry

included, so that the geometry entity is positioned as desired relative to the X, Y, Z frame.

The second point of view imagines that the XT, YT, ZT frame is initially

situated so that the geometry entity within definition space is positioned in the desired manner relative to model space. The defining matrix then

leaves the geometry entity fixed, but rotates the XT, YT, ZT frame. At

the completion of the rotation, the XT, YT, ZT frame becomes the X, Y, Z

frame. The result is that the geometry entity is then positioned as desired

relative to the X, Y, Z frame.

104
GEOMETRY - General

It is to be emphasized that the discussion here pertains to a single defining

matrix whose action in transforming coordinates can be viewed intuitively

in two ways. Each point of view stresses the temporary nature of the XT,

YT, ZT system, insofar as what is ultimately of interest is the relationship

of the geometry entity to the X, Y, Z frame.

In a case when the geometry entity to be located within model space can

be contained within a single plane, it can be seen that the definition space

concept can be used in such a way that the geometry entity as initially

described in definition space can be considered to lie in the XT, YT-plane

(i.e., the plane ZT=0). From this, it is then convenient to also allow

entities to be situated in definition space in any plane parallel to the XT,

YT plane (i.e., ZT=arbitrary constant).

As indicated in 1.5.5, each entity in this section is acted upon by a transformation matrix. This implies that each entity makes use of the

definition space concept, i.e., is defined initially in definition space, and

then transformed into model space. Thus the complete definition of a geometry entity, with respect to model space, involves the Transformation

Matrix entity. However, in some instances, it may very well be that the

transformation matrix will leave all coordinates unchanged. This will be

the case exactly when the defining matrix is the identity rotation matrix

and the translation vector is the zero vector. (In this situation, a convention is provided to prevent unnecessary processing. See the

explanation given in 2. 2. 4. 3. 7 for Field 7 of the directory entry.)

105
GEOMETRY - General

3. 1 .2 Directionality.

Within model space, all curves are directed. Such curves have associated

end points, i.e., start point and terminate point. For each entity type, the manner of assigning direction is discussed within the description of each

individual entity.

Within the entity descriptions that follow, some refer to a "counterclockwise direction" with respect to a sense of rotation in the XT,

YT plane. Since the XT, YT plane is located within three dimensional XT,

YT, ZT space, this phrase is ambiguous unless a viewing direction is specified from which to view the rotation within the plane. The viewing

direction is taken to be from the positive ZT axis looking "down" upon the

XT, YT plane. Then, if a clock were imagined to be lying "face up" in the

XT, YT plane, i.e., so as to be readable from the chosen viewing direction

along the ZT axis - the phrase "counterclockwise direction" refers to the sense of rotation which is opposite the sense of rotation of the hands of the

clock. This same notion of the meaning of counterclockwise carries over

to any plane that is parallel to the XT, YT plane.

106
GEOMETRY - General

3. 1 .3 Geometric Entities.

Entity numbers from 100 through 199 are reserved for geometry entities.

The following entity type numbers have been assigned:

Entity Type Number Entity Type

100 Circular Arc

102 Composite Curve

104 Conic Arc

106 Copious Data

Centerline

Linear Path

Section Line

Simple Closed Area

Witness Line

108 Plane

110 Line

112 Parametric Spline Curve

114 Parametric Spline Surface

116 Point

118 Ruled Surface

120 Surface of Revolution

122 Tabulated Cylinder

124 Transformation Matrix

125 Flash

126 Rational B-Spline Curve

128 Rational B-Spline Surface

130 Offset Curve

132 Connect Point

134 Node

136 Finite Element

138 Nodal Displacement and Rotation

140 Offset Surface

142 Curve on a Parametric Surface

144 Trimmed Parametric Surface

107
100 CIRCULAR ARC

3.2 Circular Arc Entity

A circular arc is a connected portion of a parent circle which consists of more than one point. The definition space coordinate system is always

chosen so that the circular arc lies in a plane either coincident with or parallel to the XT, YT plane.

3.2.1 A circular arc determines unique arc end points and an arc center point (the

center of the parent circle). By considering the arc end points to be

enumerated and listed in an ordered manner, start point first, followed by

terminate point, a direction with respect to definition space can be asso- ciated with the arc. The ordering of the end points corresponds to the

ordering necessary for the arc to be traced out in a counterclockwise manner.

This convention serves to distinguish the desired circular arc from its complementary arc (complementary with respect to the parent circle). Refer

to Section 3.1.2 for information relating to use of the term counterclockwise.

3.2.2 The direction of the arc with respect to model space is determined by the

original counterclockwise direction of the arc within definition space, in conjunction with the action of the transformation matrix on the arc.

3.2.3 In the event that a parameterization is required but not given, the default

parameterization is:

C(t) = (XI + R*cos t, Y 1 + R*sin t, ZT)

for t2 4 t ^

where, for i = 2 and 3,

(i) R = sqrt((Xi-Xl)**2 + (Yi-Yl)**2)

(ii) ti is such that (R*cos ti, R*sin ti) = (Xi - XI, Yi - Yl)

and

0 ^ t2 < 2*PI

0 4 t3- t2£ 2*PI

108
100 CIRCULAR ARC

3.2.4 Examples of the circular arc entity are shown in Figure 3-1. In Example 3 of

Figure 3-1, the solid arc is defined using point A as the start point and point

B as the terminate point. If the complementary dashed arc were desired, the

first endpoint listed in the parameter data entry would be B, and the second

would be A.

3.2.5 Directory Data

ENTITY TYPE NUMBER : 100

Parameter Data

Index Name TyPe Description

1 ZT Real Parallel ZT displacement of arc from XT, YT plane

2 XI Real Arc center abscissa

3 Y

1

Real Arc center ordinate

4 X2 Real Start point abscissa

5 Y2 Real Start point ordinate

6 X3 Real Terminate point abscissa

7 Y3 Real Terminate point

ordinate

Additional Pointers as required (see 2. 2. 4. 4. 2).

109
100 CIRCULAR ARC

110

FIG.

3-1

EXAMPLES

OF

THE

CIRCULAR

ARC

ENTITY
102 - COMPOSITE CURVE

3.3

Composite Curve Entity

A composite curve is a connected curve that results from the grouping of certain

individual constituent entities into a logical unit.

3.3.1 A composite curve is defined as an ordered list of entities of the following types:

point, line, circular arc, conic arc, parametric spline, rational B-spline, and

connect point. The list of entities appears in the parameter data entry. There,

each entity to appear in the defining list is indicated by means of a pointer to the directory entry of that entity. The order within the defining list is derived

from the order of the listing of these pointers.

3.3.2 Each constituent entity has its own transformation matrix and display attributes.

Each constituent entity may have text or properties associated with it. Because

the constituent entities are subordinate to the composite entity, the Subordinate

Entity Switch (digits 3-4 in directory entry field 9) of each constituent entity

should indicate a physical dependency.

3.3.3 A composite curve is a directed curve, having a start point and a terminate

point. The direction of the composite curve is induced by the direction of the

constituent curve entities (i.e., those constituent entities other than the point

entity) in the following way: The start point for the composite curve is the start point of the first curve entity appearing in the defining list. The terminate point

for the composite curve is the terminate point of the last curve entity appearing

in the defining list. Within the defining list itself, the terminate point of each

constituent curve entity has the same coordinates as the start point of the

succeeding curve entity.

3.3.4 The point and connect point entities are included as allowable entity types so

that properties or general notes can be attached to either the start point or the

terminate point of any constituent curve entities in the defining list.

A logical connection relationship can be indicated by having two composite

curves or a composite curve and a network subfigure reference the connect point

entity. For the special case of the logical connection of a connect point on one

subfigure instance to a connect point on another subfigure instance a

111
102 COMPOSITE CURVE

112

FIG.

3-2

EXAMPLE

OF

THE

COMPOSITE

CURVE

ENTITY
102 - COMPOSITE CURVE

composite curve is allowed whose list contains only two connect point entities

with no intervening curve entity. There are certain restrictions regarding the

use of the point entity in a composite entity. They are:

a. Two point or connect point entities cannot appear consecutively in the

defining list unless they are the only entities in the composite curve.

b. If a point or connect point entity and a curve entity are adjacent in the

defining list, then the coordinates of the point or connect point entity must

agree with the coordinates of the terminate point of the curve entity

whenever the curve entity precedes the point or connect point entity, and

must agree with the coordinates of the start point of the curve entity

whenever the curve entity follows the point or connect point entity.

c. A composite curve cannot consist of a point entity alone or a single connect

point.

3.3.5 In the event that a parametrization is required but not given, the default

parametrization of the composite curve is obtained from the parametrization of

the constituent curves as defined below As point and connect point entities do

not contribute to the parametrization of a composite curve, they are not

considered in the definition below.

Let

C

N

CC(i)

PS(i)

PE(i)

T(0)

T(i)

be the composite curve; be the number of constituent curves (N^ 1); be the i-th constituent curve, for each i such that 14i^N ; be the parametric value of the start of CC(i)

;

be the parametric value of the end of CC(i)

;

be 0.0 ; be the sum from j=l to j=i of (PE(j) - PS(j)),

for each i such that l^i ^ N.

113
102 COMPOSITE CURVE

Then

(1) the parametric values of C range from T(0) to T(N) ; and

(2) C(u) = CC(i) (u T(i-l) + PS (i)) where u is a parametric value such that

T(i-l)4u4T{i).

A composite curve consisting solely of point and/or connect point entities, will

not be given a parametrization.

3.3.6 In this section, an example of a parametrization of a composite curve entity is given.

Let N=3 and for each i such that l^i^3, let CC(i) be the i-th constituent curve

of the composite curve C. Assume the parametric values of the start and end

points of each CC(i) are given by the table

i PS(i) PE(i)

1 0.0 0.4

2 3.3 3.5

3 0.0 0.3

Then T(0) = 0.0, T(l) = 0.4, T(2) = 0.6, T(3) = 0.9, and the composite curve C, is defined from 0.0 to 0.9.

This situation described is illustrated by

The curve combining CC(1), CC(2), and CC(3) represents the composite curve C.

114
102 - COMPOSITE CURVE

3.3.7 An example of a composite curve entity is shown in Figure 3-2

3.3.8 Directory Data

ENTITY TYPE NUMBER : 102

3.3.9 Parameter Data

Index Name Type Description

1 N Integer Number of entities

2 DE Pointer

Pointers to directory

entries for the constituent

• • • entities

•

N+l DE

•

Pointer

Additional Pointers as required (see 2.2AA.2).

115
104 - CONIC ARC

3.4 Conic Arc Entity

A conic arc is a bounded connected portion of a parent conic curve which

consists of more than one point. The parent conic curve is either an ellipse, a

parabola, or a hyperbola. The definition space coordinate system is always

chosen so that the conic arc lies in a plane either coincident with or parallel to the XT, YT plane. Within such a plane, a conic is defined by the six

coefficients in the following equation.

A*XT2+ B*XT*YT + C*YT2

+ D*XT + E*YT + F = 0

3.4.1 Each coefficient is a real number. The definitions of ellipse, parabola, and

hyperbola in terms of these six coefficients are given below.

3.4.2 A conic arc determines unique arc endpoints. A conic arc is defined within

definition space by the six coefficients above and the two endpoints. By

considering the conic arc endpoints to be enumerated and listed in an ordered

manner, start point followed by terminate point, a direction with respect to definition space can be associated with the arc. In order for the desired

elliptical arc to be distinquished from its complementary elliptical arc, the

direction of the desired elliptical arc must be counterclockwise. In the case

of a parabola or hyperbola, the parameters given in the parameter data

section uniquely define a portion of the parabola or a portion of a branch of

the hyperbola; therefore, the concept of a counterclockwise direction is not

applied. (Refer to Section 3.1.2 for information concerning use of the term

"counterclockwise" .)

3.4.3 The direction of the conic arc with respect to model space is determined by

the original direction of the arc within definition space, in conjunction with

the action of the transformation matrix on the arc.

116
104 - CONIC ARC

3.4.4

The definitions of the terms ellipse, parabola, and hyperbola are given in terms

of the quantities Ql, Q2, and Q3. These quantities are:

01 - determinant of

A B/2 D/2

B/2 C E/2

D/2 E/2 F

02 — determinant of

A B/2

B/2 C

03 - A + C

3.4.5 A parent conic curve is An ellipse if Q2>0 and Ql * Q3^0.

A hyperbola if Q2<0 and Ql / 0. A parabola if Q2 = 0 and Ql / 0. An example of each type of conic arc is shown in Figure 3-3.

3.4.6 Those entities which can be represented as various degenerate forms of a conic

equation (Point and Line) must not be put into the Entity Type 104; more

appropriate Entity Types exist for these forms.

Because of the numerical sensitivity of the implicit form of the conic

description, a receiving system not using that form as its internal representation

for conics need not be expected to correctly process conics in this form unless

they are put into a standard position in definition space. A conic arc entity is said to be in a standard position in definition space provided each of its axes is

parallel to either the XT axis or YT axis and provided it is centered about the ZT

axis. For a parabola, use the vertex as the origin. The conic is moved from this

position in definition space to the desired position in space with a transformation

matrix (Entity type 124).

The form number is regarded as purely informational by such a postprocessor.

Further details may be found in Appendix E.

117
104 - CONIC ARC

118

FIG.

3-3

EXAMPLES

OF

THE

CONIC

ARC

ENTITY
104 - CONIC ARC

3.4.7 In the event that a parameterization is required but not given, the default

parameterization is:

Parabola

case A and E /0.0

if XI < X2

C(t) = (t, -(A/E)*t**2, ZT)

where, for i = 1 and 2, ti = Xi.

if X2 < XI

C(t) = (-t, -(A/E)*t**2, ZT)

where, for i = 1 and 2, ti = -Xi.

case C and D / 0.0

if Y 1 < Y2

C(t) = (-(C/D)*t**((2, t, ZT)

where, for i = 1 and 2, ti = Yi.

if Y2 < Yl

C(t) = (-(C/D)*t**2, -t, ZT)

where, for i = 1 and 2, ti = -Yi.

Ellipse

C(t) = (a*cos t, b*sin t, ZT)

for tl 4 t 4 t2

for tl ^ t ^ 12

for tl ^ t ^ t2

for tl t ^ t2

for tl ^ t ^ t2

where

a = sqrt(-F/A)

b = sqrt(-F/C)

and, for i = 1 and 2, ti is such that

(i) (a*cos ti, b*sin ti, ZT) = (Xi, Yi, ZT)

(ii) 0 ^ tl 4 2*PI

(iii) 0 4 t2 - tl ^ 2*PI

Hyperbola

case F*A < 0.0 and F*C > 0.0

a = sqrt(-F/A)

b = sqrt(F/C)

and, for i = 1,2

ti is such that

(i) (a*sec ti, b*tan ti, ZT) = (Xi,Yi,ZT)

(ii) - PI/2 < tl,t2 < PI/2

119
104 - CONIC ARC

if tl < t2

C(t) = (a*sec t, b*tan t, ZT)

if t2 < tl

C(t) = (a*sec(-t), b*tan(-t), ZT)

case F*A > 0.0 and F*C < 0.0

let a = sqrt(F/A)

b = sqrt(-F/C)

and, for i = 1,2

ti is such that

(i) (a*tan ti, b*sec ti, ZT) = (Xi,Yi,ZT)

(ii) - PI/2 < t l,t2 < PI/

2

if tl «<t2

C(t) = (a*tan t, b*sec t, ZT) for tl t ^t2

if t2 < tl

C(t) = (a*tan(-t), b*sec(-t), ZT) for -tl ^ t ^.-t2

3.4.8 Field 15 of the directory entry accommodates a Form Number. For this entity,

the options are as follows:

FORM Meaning

0 Form of parent conic curve must be determined from the general

equation.

1 Parent conic curve is an ellipse (See example 1, Figure 3-3).

2 Parent conic curve is a hyperbola (See example 2, Figure 3-3).

3 Parent conic curve is a parabola (See example 3, Figure 3-3).

for 1 ^ t ^ t2

for -tl £ t4-t2

120
104 - CONIC ARC

3.4.9

3.4.10

Directory Data

ENTITY TYPE NUMBER : 104

Parameter Data

Index Name TyPe Description

1 A Real Conic Coefficient

2 B Real Conic Coefficient

3 C Real Conic Coefficient

4 D Real Conic Coefficient

5 E Real Conic Coefficient

6 F Real Conic Coefficient

7 ZT Real ZT Coordinate of

plane of definition

8 XI Real Start Point Abscissa

9 Y

1

Real Start Point Ordinate

10 X2 Real Terminate Point

Abscissa

11 Y2 Real Terminate Point

Ordinate

Additional Pointers as required (see 2.2.4.4.2).

121
106 - COPIOUS DATA

3.5 Copious Data Entity

This entity stores data points in the form of pairs, triples, or sextuples. An

interpretation flag value signifies which of these forms is being used. This value

is one of the parameter data entries. The interpretation flag is abbreviated

below by the letters IP.

Data points within definition space which lie within a single plane are specified

in the form of XT, YT coordinate pairs. In this case, the common ZT value is also needed. Data points arbitrarily located within definition space are specified

in the form of XT, YT, ZT coordinate triples. Data points within definition

space which have an associated vector are specified in the form of sextuples; the

XT, YT, ZT coordinates are specified first, followed by the i, j, k coordinates of

the vector associated with the point. (Note that, for an associated vector, no

special meaning is implicit.)

Field 15 of the directory entry accommodates a Form Number. For this entity,

the options are as follows:

FORM Meaning

1 Data points in the form of coordinate pairs. All data points lie in a plane ZT= constant. (IP=1)

2 Data points in the form of coordinate triples. (IP=2)

3 Data points in the form of sextuples. (IP=3)

11 Data points in the form of coordinate pairs which represent the

vertices of a planar, piecewise linear curve (piecewise linear

string is sometimes used). All data points lie in a plane

ZT=constant. (IP=1)

12 Data points in the form of coordinate triples which represent the

vertices of a piecewise linear curve (piecewise linear string is sometimes used). (IP=2)

13 Data points in the form of sextuples. The first triple of each

sextuple represents the vertices of a piecewise linear curve

(piecewise linear string is sometimes used). The second triple is an associated vector. (IP=3)

20 Centerline Entity through points (IP=1)

122
106 COPIOUS DATA

21 Centerline Entity through circle centers (IP=1)

31 Section Entity Form 31 (IP=1)

32 Section Entity Form 32 (IP=1)

33 Section Entity Form 33 (IP=1)

34 Section Entity Form 34 (IP=1)

35 Section Entity Form 35 (IP=1)

36 Section Entity Form 36 (IP=1)

37 Section Entity Form 37 (IP=1)

38 Section Entity Form 38 (IP=1)

40 Witness Line Entity (IP=1)

63 Simple Closed Area Entity (IP=1)

The linear path is an ordered set of points in either 2- or 3-dimensional space.

These points define a series of linear segments along the consecutive points of

the path. The segments may cross or be coincident with each other. Paths may

close, i.e., the first path point may be identical to the last.

The linear path is implemented as two forms of the copious data block (entity

number 106). Form 11 is for 2-dimensional paths and form 12 is for 3-

dimensional paths. This entity will be closely associated with properties

indicating functionality and fabrication parameters, such as Line Widening.

Refer to the centerline and witness line entities in Section 4 of this specification

for examples of Form Numbers 20, 21 and 40. Each of these annotation entities

contains a description of how the associated copious data are to be interpreted.

Forms 31-38 provide for the transfer of graphical information and are defined

here for compatability with previous versions of the specification. The

Sectioned Area Entity (type 230) provides a more compact method for

transferring this information.

A simple closed area is a bounded region of XY coordinate space represented by

a set of points that forms a series of connected linear segments. These segments

must form a closed loop, i.e., the first point of the boundary of the area and the

last point must be identical. No segments of this entity are allowed to intersect

or be coincident except for the closing of the entity at the initial and final

123
106 COPIOUS DATA

points. This entity will be closely related to properties that indicate

functionality of closed regions, such as Region Fill and Region Restriction.

The area is implemented as Form 63 of entity 106, the copious data block.

3.5.1 Directory Data

ENTITY TYPE NUMBER : 106

3.5.2 Parameter Data

Index Name

IP

TyPe

Integer

Description

Interpretation Flag

IP=1 x,y pairs, common z IP=2 x,y,z coordinates

IP=3 x,y,z coordinates and

i,j,k vectors

2 N

1

Integer Number of n-tuples

For IP=1 (x,y pairs, common z):

3 ZT Real Common z displacement

4 XI Real First data point abscissa

5 Y

1

Real First data point ordinate

3+2N YN

For IP=2 (x,y,z triples):

Real Last data point ordinate

3 XI Real First data point x value

4 Y

1

Real First data point y value

5 Z1 Real First data point z value

2+3N ZN Real Last data point z value

124
106 - COPIOUS DATA

For IP=3 (x,y,z, i,j,k sextuples):

3 XI Real First data point x value

A Y

1

Real First data point y value

5 Z1 Real First data point z value

6 11 Real First data point i value

7 31 Real First data point j value

8

0

K

1

Real First data point k value

©

©2+6N0KN Real Last data point k value

Additional pointers as required (see sec. 2. 2A. 4. 2).

125
108 PLANE

3.6 Plane Entity

The plane entity can be used to represent an unbounded plane, as well as a bounded portion of a plane. In either of the above cases, the plane is defined

within definition space by means of the coefficients A, B, C, D, where at least one of A, B, and C is non-zero and

A*XT + B*YT + C*ZT = D

for each point lying in the plane, and having definition space coordinates (XT,

YT, ZT).

3.6.1 The definition space coordinates of a point, as well as a size parameter, can be

specified in order to assist in defining a system-dependent display symbol. These

values are parameter data entries six through nine, respectively. This

information, together with the four coefficients defining the plane, provides

sufficient information relative to definition space in order to be able to position

the display symbol. (In Examples 1 and 3 of Figure 3-4, the dashed curve and the

crosshair together constitute the display symbol.) Setting the size parameter to zero indicates that a display symbol is not intended.

3.6.2 The case of a bounded portion of a fixed plane is indicated by the existence of a

pointer to a closed curve lying in the plane. This is parameter five. The only

allowed coincident points for this curve are the start point and the terminate

point. Setting this value to zero indicates the case of an unbounded plane.

3.6.3 The case of a bounded portion of a fixed plane minus some portion(s) of that

plane, such as those shown in Figure 3-5, are expressed through the use of the

Single Parent Associativity (Type 402, Form 9) where the outer closed curve

defines the parent bounded plane and each internal closed curve defines some

child bounded plane to be subtracted from the parent. Each of these planes

(parent and child) is a separate plane entity in the IGES file and has a backpointer to the associativity structure. The child plane entity will have a subordinate entity switch class of 01 (Physically Dependent).

126
108 - PLANE

\ \

\

* \

Y__ --A

(\i

r~~n

l * !

i

i

u

Q-

<

X

UJ

D

UJ

D

Z3

O

CD

Z3

sr

i

LD—

Li127
108 - PLANE

FIG, 3-5 SINGLE PARENT ASSOCIATIVITY AS USED WITH A COLLECTION

OF BOUNDED PLANES

128
108 - PLANE

3.6.4 Field 15 of the directory entry accommodates a Form Number. For this entity,

the options are as follows:

FORM Meaning

+ 1 Bounded planar portion is considered positive.

-1 Bounded planar portion is considered negative (hole).

3.6.5 Directory Data

ENTITY TYPE NUMBER : 108

3.6.6 Parameter Data

Index Name TyPe Description

1 A Real

2 B Real

Coefficients of Plane

3 C Real

4 D Real

5 PTR Pointer Pointer to directory entry of closed curve entity or zero

6 X Real XT coordinate of location

display symbol

point for

7 Y Real YT coordinate of location

display symbol

point for

8 Z Real ZT coordinate of location

display symbol

point for

9 SIZE Real Size parameter for display symbol

Additional Pointers as required (see 2.2.4. 4.2).

129
110 - LINE

3.7 Line Entity

A line is a bounded, connected portion of a parent straight line which consists of more than one point.

A line is defined by its end points. Each end point is specified relative to definition space by a triple of coordinates. With respect to definition space, a

direction is associated with the line by considering the start point to be listed

first and the terminate point second.

The direction of the line with respect to model space is determined by the

original direction of the line within definition space, in conjunction with the

action of the transformation matrix on the line. Examples of the line entity are shown in Figure 3-6.

3.7.1 In the event that a parameterization is required, the default parameterization is:

C(/) — P\ + t(Pi~P\i for

3.7.2 Directory Data

ENTITY TYPE NUMBER : 110

3.7.3 Parameter Data

Index Name TyPe Description

1 XI Real Start Point PI

2 Y

1

Real

3 Z1 Real

4 X2 Real Terminate Poii

5 Y2 Real

6 Z2 Real

Additional Pointers as required (see 2. 2. 4. 4.2).

130
110 - LINE

n

UJ

cl

<

X

UJ

131
112 - PARAMETRIC SPLINE CURVE

3,8 Parametric Spline Curve Entity

(Consult Appendix D for additional mathematical details)

The parametric spline curve is a sequence of parametric polynomial segments.

The CTYPE value in Parameter 1 indicates the type of curve as it was

represented in the sending (pre-processing) system before conversion to this entity.

3.8.1 The N polynomial segments are delimited by the breakpoints T( 1), T(2),

...,T(N+1). The coordinates of the points in the i-th segment of the curve are given by the following cubic polynomials (the coefficients D, or C and D will be zero if the polynomials are of degrees 2 or 1, respectively):

X(u)-AX(i)+BX(i) •s+CXii) *s

7+DX(i) V

Y(u)-A nO+BYU) •s+CY(i) •s

7+DY(i) V

Z(u)-AZ{i)+BZ(i) °*+CZ(i) V+Z>Z(/) V

where

r(/)<ir< 7(/+l),/-l,...,Af

S-U-Ki)

In order to avoid degeneracy, for each i at least one of the nine real coefficients,

BX(i), CX(i), DX(i), BY(i), CY(i), DY(i), BZ(i), CZ(i), and DZ(i) must be non-zero.

3.8.2 If the spline is planar, it must be parametrized in terms of the X and Y

polynomials only. The Z polynomial will then be zero except for each i, the AZ(i)

term which indicates the Z-depth in definition space.

3.8.3 The parameter H is used as an indicator of the smoothness of the curve. If H=0,

the curve is continuous at all breakpoints. If H=l, the curve is continuous and

has slope continuity (see section 6.3 of FAUX79) at all breakpoints. If H=2, the curve is continuous and has both slope and curvature continuity at all breakpoints

(see section 6.3 of Faux79).

132
112 - PARAMETRIC SPLINE CURVE

3.8.4 To enable determination of the terminate point and derivatives without

computing the polynomials, the Nth polynomials and their derivatives are evaluated at u = T(N+1). These data are divided by appropriate factorials and

stored following the polynomial coefficients. For example, the name TPY3 will

be used to designate 1/3! times the third derivative of the Y polynomial for the

Nth segment evaluated at u=T(N+l), the parameter value corresponding to the

terminate point. Note that these data are redundant as they are derived from

the data defining the Nth polynomial segment.

3.8.5 An example of a parametric spline is shown in Figure 3-7. Additional examples

are shown in Figure 3-8.

3.8.6 Directory Data

ENTITY TYPE NUMBER : 112

3.8.7 Parameter Data

Index Name TyPe Description

1 CTYPE Integer Spline Type

(l=Linear

2=Quadratic

3=Cubic

4=Wilson-Fowler

5=Modified

Wilson-Fowler

6=B Spline)

2 H Integer Degree of continuity with

respect to arc

length

3 NDIM Integer 2=planar

3=non-planar

4 N Integer Number of segments

5 T(l) Real Break points of

• • piecewise

•

• 5+N T(N+1)

polynomial

133
CURVE

=(

X(U),

Y(U),

Z(U)

),

FOR

T(l)

£

U

S

T(N+1)

N

=3

SEGMENTS

112 - PARAMETRIC SPLINE CURVE

N-\ isr> (sn» /—s /-s /-S

/—s /<> /—

0

CM CM CM wI— I— I

1 I I

Ma.

>—

Cl. X

Q_

II O

CM —i

Q_ Q_

-h (N

' ^

w

aaa

•—t CM PO

' / V-/ s_*> >->->-

c <c c

«• II >-o -a*

CL. Q_

* <C oX LU

Q- >

CM

^ <

II *-* or O LU

a. c

a

CM I'C v-' s_^

II II II —i CM fv\

CL. Q- QII OO

Q£

a- >—

Q_ LL.

CM

OC

LD

UJ

CO

QCO

* * * rv

CM CM CM ^ w X >- PM Q Q Q

+ + +

CM CM CM^

/>

CM CM CM ^ ' / V /

I— I— I

I I I S_x v—

/

* *

/—v /-s CM CM CM —/ w X >- PM

(_> O O

+ + +

rN

rs

CM CM CM

I I

* * * CM CM CM

' ' V X >- PM

CQ CQ QQ + + +

/—S /-V CM CM CM

'—«< >

ii ii ii x >- rM

134

FIGURE

3-7

EXAMPLE

OF

THE

PARAMETRIC

SPLINE

CURVE

ENTITY
112 - PARAMETRIC SPLINE CURVE

135
112 - PARAMETRIC SPLINE CURVE

Index Name Type Description

6+N AX(1) Real X coordinate

polynomial

7+N BX(1)

8+N CX(1)

9+N DX(1)

10+N AY(1) Y coordinate

1 1+N BY(1) polynomial

12+N CY(1)

13+N DY(1)

14+N AZ(1) Z coordinate

15+N BZ(1) polynomial

16+N CZ(1)

17+N DZ(1)

. Subsequent X, Y, Z

. polynomials concluding

with the twelve

coefficients of the Nth

polynomial segment.

(The parameters that follow comprise the evaluations of the polynomials of the Nth

segment and their derivatives at the parameter value u=T(N+l) corresponding to the

terminate point. Subsequently these evaluations are divided by appropriate factorials.)

136
112 - PARAMETRIC SPLINE CURVE

6+13*N TPXO Real X value

TPX

1

X first derivative

TPX2 X second derivative/2!

TPX3 X third derivative/3!

TPYO Y value

TPY

1

TPY2

TPY 3 TPZO Z value

TPZ1

TPZ2

TPZ3

Additional Pointers as required (see 2. 2. 4. 4. 2)

Software to convert between parametric spline curves or surfaces and the corresponding

rational B-spline curves or surfaces is available from the IGES office at the National

Bureau of Standards. Materials provided include a magnetic tape of Pascal source code, a

listing of the code, and accompanying documentation.

137
114 - PARAMETRIC SPLINE SURFACE

3.9 Parametric Spline Surface Entity

(Consult Appendix D for additional mathematical details)

The parametric spline surface is a grid of parametric polynomial patches.

PTYPE in the Parameter Data Section indicates the type of patch under

consideration.

3.9.1 The MxN grid of patches is defined by the u breakpoints TU(1), ... , TU(M+1) and

the v breakpoints TV(1), ... , TV(N+1). The coordinates of the points in each of

the patches are given by the general bicubic polynomials (given here for the (i, j) Patch).

X(u,v) - AX(ij)+BX(ij) *s+CX(iyj) V+Z>Jr(iJ) V

+ EX(iJ) *t+FX(iJ) •Ps+GXUj

)

*fs2+HX(iJ

)

Vs3 + KX(iJ) *t

2+LX(iJ) *t

2 *s+MX(ij) m

t2m

s

2+NX{iJ) */2 V

+ PX(iJ) */3+ QXUJ) *t

3 •s+RXUj) */3 •s

2+SX(ij) V*s3

Y(u,v) - •••

Z(m,v) — •••

where

m/)<M<m/+n, /-i m

s**u— TU (/) and

my)<v<7ro+i),

t— v— TV(J).

3.9.2 Parameters with the following indices shall be ignored by post-processors:

for k=l,2,3 M 7+M+N+48* (k*N+ (k-1))

through

6+M+N+48* (k*(N+l))

(i.e., the (N+l) row of patches)

138
114 - PARAMETRIC SPLINE SURFACE

7+M+N+48* (M*(N+1))

through

6+M+N+48*(M+l)*(N+l)

(i.e., the (M+l) column of patches).

To maintain upward compatibility with previous versions of IGES, the preprocessors must either enter a real number for each of these parameters or a

series of parameter delimiters (see 2.2.3). These values act as place holders in

the parameter list. These parameters were intended to handle first, second, and

third partial derivatives of the row and M**1 column of patches along the

outer edge or boundary. However, these parameters can be computed by the

receiving system, as needed, from the other parameter values contained in this

entity, and therefore are not needed.

139
114 - PARAMETRIC SPLINE SURFACE

+ 4- ZZw w

D>

4- ^ 2-W W

D>

l-H

•• It D>

UJo

<

II. cccd in “In m insz

•

•• « 4- -zw w

:>>

I— h

•• •• D>

4- +

CO CO

cvT c\T

x >. < <

•• H

4-

co_

cvT v—N

< ^ r« ** > > >

• • • O D => ^ w w

X >- N

140

FIGURE

3

9

EXAMPLE

OF

THE

PARAMETRIC

SPLINE

SURFACE

ENTITY
114 - PARAMETRIC SPLINE SURFACE

3.9.3 An example of the bicubic surface is shown in Figure 3-9.

3.9.4 Directory Data

ENTITY TYPE NUMBER : 1 14

3.9.5 Parameter Data

Index Name Description

1 CTYPE Integer Spline Boundary

Type

(l=Linear

2=Quadratic

3=Cubic

4=Wilson-Fowler

5=Modified

Wilson-Fowler

6 = B spline)

2 PTYPE Integer Patch Type

(1=C artesian

Product

0=Unspecified)

3 M Integer Number of u segments

4 N Integer Number of v segments

5 TU(1) Real Breakpoints in u (u values of

grid lines)

5+M TU(M+1)

141
114 - PARAMETRIC SPLINE SURFACE

Index Name TyPe Description

6+M

6+M+N

TV(1)

TV(N+1)

Real Breakpoints in v

(v values of grid

lines)

7+M+N AX(1,1) Real X Coefficients of

•

• 22+M+N SX(1,1)

(1,1) Patch

23+M+N AY(1,1) Y Coefficients of

38+M+N SY(1,1)

(1,1) Patch

39+M+N AZ(1,1) Z Coefficients of

»> .

(1,1) Patch

54+M+N SZ(1,1) Real

55+M+N AX(1,2) Real Coefficients of

. . .

(1,2) Patch

102+M+N SZ(1,2) Real

•

7+M+N+48*(N-l) AX(1,N) Real Coefficients of

• • .

(1,N) Patch

6+M+N+48*N SZ(1,N) Real

7+M+N+48*N

. Real Arbitrary Values

6+M+N+48*(N+l)

• Real

•

7+M+N+48*(N+ 1) AX(2,1) Real Coefficients of

• • .

(2,1) Patch

6+M+N+48*(N+2) SZ(2, 1) Real

• • •

• • •

• • •

142
114 - PARAMETRIC SPLINE SURFACE

Index Name Jype Description

7+M+N+48*(2*N) AX(2,N) Real Coefficients of

• • .

(2,N) Patch

6+M+N+48*(2*N+l) SZ(2,N) Real

•

7 + M+N+48*(2*N + 1) Real Arbitrary Values

6+M+N+48*(2*N+2) Real

•

M+N+48*[(J- 1)*(N+1)+K- 1] AX(3,K) Real Coefficients of

• . .

(3,K) Patch

6+M+N+48*£(J-1)*(N+1)+k] SZ(J,K) Real

•

7+M+N+48* [(M-1)*(N+ l)+N-ll AX(M,N) Real Coefficients of

• • . (M,N) Patch

6+M+N+48*[(M-1)*(N+1)+n] SZ(M,N) Real

•

7+M+N+48*[(M- 1)*(N+1)+n] Real Arbitrary Values

6+M+N+48*[(M-l)*(N+l)+(N+l)] Real

•

7+M+N+48*[M*(N+l)] Real Arbitrary Values

6+M+N+48*[M*(N+l)+(N+l)] Real

•

Additional Pointers as required (see 2. 2. 4. 4. 2).

Software to convert between parametric spline curves or surfaces and the corresponding

rational B-spline curves or surfaces is available from the IGES office at the National

Bureau of Standards. Materials provided include a magnetic tape of Pascal source code, a

listing of the code, and accompanying documentation.

143
116 - POINT

3.10

3.10.1

3.10.2

Point Entity

A point is defined by its coordinates in definition space. Examples of the point

entity are shown in Figure 3-10.

Directory Data

ENTITY TYPE NUMBER: 116

Parameter Data

Index Name Type Description

1 X Real Coordinates

2 Y Real of point

3 Z Real

4 PTR Pointer Pointer to directory

entry of

subfigure instance

specifying the display

symbol.

If zero, no display

symbol specified.

Additional Pointers as required (see 2.2.4.4.2).

144
116 - POINT

145
118 RULED SURFACE

3.1 1 Ruled Surface Entity

A ruled surface is formed by moving a line connecting points of equal relative arc length (Form 0) or equal relative parametric value (Form 1) on two

parametric curves from a start point to a terminate point on the curves. The

parametric curves may be points, lines, circles, conics, parametric splines,

rational B-splines, composite curves, or any parametric curves defined in this

Specification (both planar and non-planar).

3.11.1

Form 0.

In this case, DEI and DE2 specify the defining rail curves, but their given

parametrizations are not the ones used to generate the ruled surface.

Instead, their arc length reparametrizations, Cl and C2 (respectively), are

used.

Form 1.

In this case, DEI and DE2 specify the defining rail curves, Cl and C2

(respectively). Moreover, their given parametrizations are the ones used to generate the ruled surface.

For both Form 0 and Form 1.

In either case, the two curves are expressed parametrically by the

functions (Cl^(t), Cly(t), Cl^(t)) and (C2^(s), C2y(s), C2^(s)), with range

t^b and c^ls^dj then the coordinates of the points on the ruled

surface can be written as

X(u,v) - (1 — v) *C\ z (f)+v*C2z (s) F(w,v) - (1- v) *CT *-(/)+ v*C2 y(s)

Z(u,v) = (l-v)*Cl z (0+VC2z (s) where

0<v<l,

t=a+u*(b-a)

s=c+u*(d-c), if DIRFLG=0

s=d+u*(c-d), if DIRFLG=1

146
118 - RULED SURFACE

Cl(t) and C2(s) are said to be of equal relative parametric value if t and s are evaluated at the same u value.

3.11.2 In case DIRFLG=0, then the first point of curve 1 is joined to the first point of curve 2 and the last point of curve 1 to last point of curve 2. If DIRFLG=1, then

the first point of curve 1 is joined to the last point of curve 2, the last point of curve 1 to the first point of curve 2.

3.11.3 If DEVFLG=1, then the surface is a developable surface; if DEVFLG=0, the

surface may or may not be a developable surface.

3.11.4 Field 15 of the directory entry accommodates a Form Number. For this entity

the options are as follows:

FORM MEANING

0 Equal relative arc length

1 Equal relative parametric values.

The default is FORM 0.

3.11.5 An example of the Ruled Surface Entity is shown in Figure 3-11. Additional

examples are shown in Figure 3-12.

147
118 - RULED SURFACE

FIG. 3-11 EXAMPLE OF THE RULED SURFACE ENTITY

148
118 - RULED SURFACE

m

til

Q.

<

X

Ul

CM

HI

-J

CL

<

X

LU

CNS

i—l

I

CD

cluj

-J

(L

<

X

UJ
118 - RULED SURFACE

3. 1 1 .6 Directory Data

ENTITY TYPE NUMBER : 118

3. 1 1 .7 Parameter Data

Index Name Description

1 DEI Pointer Pointer to first curve

2 DE2 Pointer Pointer to second curve

3 DIRFLG Integer Direction flag

(0=join first to

first, last to

last l=join first to

last, last to

first)

4 DEVFLG Integer

Additional pointers as required (see 2. 2. 4. 4. 2).

Developable

surface flag

(l=Developable,

0=Possibly not)

150
120 - SURFACE OF REVOLUTION

3.12 Surface of Revolution Entity

A surface of revolution is defined by an axis of rotation (which must be a line

entity), a generatrix, and start and terminate rotation angles. The surface is created by rotating the generatrix about the axis of rotation through the start and terminating angles. Since the axis of rotation is a line entity, it contains in

its parameter data section the coordinates of its start point first, followed by

the coordinates of its terminate point. The angles of rotation are counterclockwise in the positive direction (See section 3.1.2). The generatrix

may be a conic arc, line, circular arc, parametric spline curve, rational B-spline curve, or composite curve.

3.12.1 Examples of surface of revolution entities are shown in Figure 3-13.

3.12.2 The start and terminate angles of the surface can be explained by geometric

construction. Refer to Figure 3-14 and the following:

a. Select a point on the generatrix which does not lie on the axis of

rotation; label the point PI.

b. Construct a line through PI such that it is perpendicular to the axis of

rotation extended; label this line LI.

c. Construct a plane PN1 containing LI and perpendicular to the axis of

rotation.

d. All rotations in the plane PN1 about the axis of rotation are applied

counterclockwise according to the method described in 3.12.

e. Rotate counterclockwise the line LI and the point selected from the

generatrix the number of radians indicated in the start angle resulting

in Ll^. The location is labeled LOCI.

151
120 SURFACE OF REVOLUTION

f. Rotate counterclockwise the line LI and the point PI selected from the

generatrix an additional number of radians given by the terminate angle

minus the start angle resulting in Lly^. The second location of the

point is labeled LOC2.

g. The resulting surface is that generated by rotating the generatrix from

LOCI to LOC2.

3.12.3 Directory Data

ENTITY TYPE NUMBER : 120

3. 1 2.4 Parameter Data

Index Name Description

1 DEI Pointer Pointer to a line entity (axis

of revolution)

2 DE2 Pointer Pointer to generatrix

3 SA Real Start angle in radians

4 TA Real Terminate angle in radians

Additional pointers as required (see 2. 2. 4. 4. 2).

152
EXAMPLE

I

EXAMPLE

2

EXAMPLE

120 - SURFACE OF REVOLUTION

ro

«—

i

i *>

to
120 - SURFACE OF REVOLUTION

FIG. 3-14 SURFACE OF REVOLUTION START AND TERMINATING ANGLES

154
122 - TABULATED CYLINDER

3.13 Tabulated Cylinder Entity

A tabulated cylinder is a surface formed by moving a line segment called the

generatrix parallel to itself along a curve called the directrix. This curve may

be a line, circular arc, conic arc, parametric spline curve, rational B-spline curve, or composite curve.

3.13.1 It must be pointed out that different parameterizations of the generating curves

will produce different parameterized surfaces, but the underlying point set surface will still be the same. Assuming a parameterization u on the directrix

and v on the generatrix, both of which run from 0 to 1, we can express the points on the surface by

x(uy v) - ar(«)+v(ur-ar(o»

t(u,v) - cnuHvar-crm

Z(u,v) - CZ(w)+V(IZ-CZ(Q))

where 0<«<1, 0<v<l

and CX, CY, CZ represent the X, Y, Z components, respectively, along the

directrix curve, while (CX(Q), CY(0), CZ(0)) and (LX, LY, LZ) represent

the coordinates of the start and terminate points, respectively, of the

generatrix.

3.13.2 An example of the tabulated cylinder is shown in Figure 3-15.

155
122 - TABULATED CYLINDER

156
122 - TABULATED CYLINDER

3.13.3 Directory Data

ENTITY TYPE NUMBER : 122

3.13.4 Parameter Data

Index Name TyPe Description

1 DEI Pointer Pointer to directrix curve

2 LX Real Coordinates of the terminate

point of the generatrix. The

start point of the generatrix

is identical with the start point of the directrix.

3 LY Real

4 LZ Real

Additional Pointers as required (see 2.2.4.4.2).

157
124 TRANSFORMATION MATRIX

3.14 Transformation Matrix Entity

The Transformation Matrix entity transforms three-row column vectors by means of a matrix multiplication and then a vector addition. The notation for

this transformation is

Rll R 12 R 13* "xinput' *Tf 'xoutput'

r 21 r 22 r 23 YINPUT + t2

= YOUTPUT

_ r 31 r 32 r 33. ZINPUT _t3 . .ZOUTPUT,

Here, col ^XINPUT, YINPUT, ZINPUTj (i.e., the column vector) is the vector being

transformed, and col ^XOUTPUT, YOUTPUT, ZOUTPUtJ is the column vector resulting

from this transformation. R =

jjRjjj is a 3 row by 3 column matrix of real numbers,

and T=col £t 1,T2,T3J is a three-row column vector of real numbers. Thus, 12 real

numbers are required for a Transformation Matrix entity. This entity can be

considered to be an "operator" entity in that it starts with the input vector,

operates on it as described above, and produces the output vector.

3.14.1 Frequently, the input vector lists the coordinates of some point in one coordinate

system, and the output vector lists the coordinates of that same point in a second coordinate system. The matrix R and the translation vector T then

express a general relationship between the two coordinate systems. By

considerating special input vectors such as ccl^l,0,oj, col£o,l,oj, and col [o,0,lJ

and computing the corresponding output results, a geometric appreciation of the

spatial relationship between the two coordinate system can be gained.

For example, for

i

o o

i ’o'

R = 0 1 0 T = 0

-1 0 0 _ 0 .

158
124 - TRANSFORMATION MATRIX

the spatial relationship of the input and output cordinate systems is the

following:

ZOUTPUT

All coordinate systems are assumed to be orthogonal, cartesian, and right-handed

unless specifically noted otherwise.

3.14.2 Following are three specific areas where the Transformation Matrix entity is used to transform coordinates between coordinate systems. Each example area

illustrates a specific choice of input and output coordinate system. Other

choices of coordinate systems may be appropriate in other application areas.

The usual situation for this type of use of the Transformation Matrix entity is when the input vector refers to the definition space coordinate system for a

certain entity, and the output vector refers to the model space coordinate

system. (See Sect. 3.1.1) In this case, the matrix R is referred to as the defining

matrix, and the Transformation Matrix entity defining R and T is pointed to in

field seven (transformation matrix field) of the directory entry of the entity.

(See Sect. 2. 2. 4. 3. 7) In this use of the Transformation Matrix entity, the matrix

R is subject to the restrictions given in Form 0 and Form 1 below.

159
124 - TRANSFORMATION MATRIX

A second situation is the case when the input vector refers to the model space

coordinate system and the output vector refers to a viewing coordinate system.

In this case, the matrix R is referred to as a view matrix, and is subject to the

restrictions given in Form 0 below. Note that when a planar entity is viewed at true length (i.e., the viewing plane is parallel to the plane containing the entity)

then the rotation matrix pointed to by DE Field 7 of the planar entity will be the

inverse (=matrix transpose) of the matrix pointed to by DE Field 7 of the View

entity. (See Sect. 4.3.11)

A third situation involves finite element modeling applications. Here, it may be

the case that an input coordinate system is related to an output coordinate

system by a particular R and T, and, in turn, the output coordinate system is then taken as an input coordinate system for a second R and T combination, and

so on. These coordinate systems are frequently called local coordinate systems.

Model space is frequently called the reference system. For example, the

location of a finite element node may be given in one local coordinate system,

which may serve as the input coordinate system for a second local coordinate

system, which in turn serves as the input coordinate system for the model space

coordinate system which is the reference system. Allowable forms of the matrix

R for these applications are detailed in Forms 10, 11, and 12 below.

3.14.3 Whenever coordinate systems are related successively to each other as described

above, a basic result is that the combined effect of the individual coordinate

system changes can be expressed in terms of a single matrix R and a single

translation vector T. For example, if the coordinate system change involving the

matrix R2 and the translation vector T2 is to be applied following the coordinate

system change involving the matrix R1 and the translation vector Tl, then the

matrix R and the translation vector T expressing the combined changes are R=(R2) (Rl) and T = (R2) (Tl) + T2.

Here, (R2) (Rl) denotes matrix multiplication of 3x3 matrices, where

multiplication order is important. The matrix R and the translation vector T are computed similarly whenever more than two coordinate system changes are to be

applied successively.

160
124 - TRANSFORMATION MATRIX

Successive coordinate system changes are specified by allowing a Transformation

Matrix entity to reference another Transformation Matrix entity through Field 7

of the Directory Entry. In the example above, the Transformation Matrix entity

containing R1 and TI would contain in its Directory Entry Field 7 a pointer to the Transformation Matrix entity containing R2 and T2. The general rule is that

Transformation Matrix entities applied earlier in a succession will reference

Transformation Matrix entities applied later. Note that the matrix product

(R2) (Rl) in the example above does not appear explicitly in the data, but, if needed, must be computed according to the usual rules of matrix multiplication.

A second example of coordinate systems being related successively (or

"concatenated", or "stacked"), in addition to the finite element example

mentioned above, involves one manner of locating into model space a qonic arc

that is in standard position in definition space. In this case, Rl and Tl move the

conic arc from its standard position to an arbitrary location in any plane in

definition space satisfying ZT=constant. (Therefore, R 133 = 1 . 0 , Rl 31 =Rl 32 =Rli 3

= Rl23=0.0. Tl can be an arbitrary translation vector.) R2 and

T2 then position the relocated conic arc into model space. (R2 can be an

arbitrary defining matrix and T2 can be an arbitrary translation vector.) Note

that for Rl and Tl, both the input vector and the output vector refer to the same coordinate system, namely, the definition space for the conic arc.

3.14.4 A 3x3 matrix R is called orthogonal provided its transpose, R*, about the main

diagonal yields a matrix inverse for R. The columns of an orthogonal matrix

considered as vectors form an orthogonal collection of unit vectors. As (R't

) t =R,

the transpose of an orthogonal matrix is again an orthogonal matrix. The

determinant of an orthogonal matrix is equal to either plus one or minus one. In the event R is an orthogonal matrix with determinant equal to positive one, R

can be expressed as a rotation about an axis passing through the origin. In this

event, R is referred to as a rotation matrix. In the event R is an orthogonal

matrix with determinant equal to negative one, R can be expressed as a rotation

about an axis passing through the origin followed by a reflection about a plane

passing through the origin perpendicular to the axis of rotation.

161
124 - TRANSFORMATION MATRIX

3.14.5 Allowable Form Numbers. The defining matrix of an entity must use either

Form zero or Form one. A defining matrix associated with a view entity must

use Form zero.

Form 0: (default) R is an orthogonal matrix with determinant equal to positive one. T is arbitrary. The columns of R taken in order form a right-handed triple

in the output coordinate system.

Form 1: R is an orthogonal matrix with determinant equal to negative one. T is arbitrary. The columns of R taken in order form a left-handed triple in the

output coordinate system.

3.14.6 Forms 10, 11, 12. These form numbers indicate special matrices used in conjunction with the node entity (type number 134).

Form 10: This form number conveys special information when used in conjunction with the Node entity (type number 134) in Finite Element

Applications.

Refer to Fig. 3- 17(a) for notation. The matrix R and the vector T are used to transform coordinate data from the ul,u2,u3 coordinate

system to the x,y,z local system.

The ul,u2,u3 coordinate system has its origin at an arbitrary fixed

point col XOFFSET, YOFFSET, ZOFFSET in the x,y,z coordinate

system and is assumed to be displaced parallel to that reference

coordinate system. Thus,

0 o 1

1

' XOFFSET*

R = 0 1 0 , T = YOFFSET

i o o 1 . ZOFFSET

.

162
124 - TRANSFORMATION MATRIX

Z

Figure 3-17 Displacement Components

163
124 - TRANSFORMATION MATRIX

Form 1 1:

so that

’l 0 o" 'ul* 'xoffset" "xlocal'

0 1 0 u2 + YOFFSET = YLOCAL

.0 0 1. u3. _ZOFFSET

.

.ZLOCAL.

Note that the orientation of the two coordinate systems can be

described by saying that the ul,u2,u3 coordinate system is the

system obtained by imposing orthogonal curvilinear coordinates

onto the x,y,z space and then constructing unit tangent vectors to the three curvilinear coordinate curves at the given fixed point to serve as basis vectors. In this special case of parallel

displacement, the curvilinear coordinates imposed are identical to' the existing x,y,z coordinates.

This form number conveys special information when used in conjunction with the Node entity (type number 134) in Finite

Element applications.

Refer to Figure 3- 17(b) for notation. The matrix R and the vector

T are used to transform coordinate data from the ul, u2, u3

coordinate system to the x,y,z local system.

The ul, u2, u3 coordinate system has its origin at an arbitrary fixed

point

XOFFSET = rGcos Q0

YOFFSET = r 0sin Q0

ZOFFSET = zQ

r o

0

0 0o 360°

- oo <zQ < oO

for r o=0, take 9=0°

in the x,y,z coordinate system. The ul,u2,u3 system is the system

obtained by imposing orthogonal curvilinear coordinates onto the

x,y,z space which are the cylindrical coordinates (r,Q,z) with

x = r cos 9

y

= r sin 9

z = z,

164
124 - TRANSFORMATION MATRIX

and then constructing unit tangent vectors to the three curvilinear

coordinate curves at the given fixed point to serve as basis vectors.

Thus, the relationship between the ul, u2, u3 and the x,y,z local

coordinate system is given by

cos90 -sin90 o' uf XOFFSET* ’xlocal"

sin90 cos90

0 u2 + YOFFSET = YLOCAL

o 0 1 . _u3_ . ZOFFSET

.

ZLOCAL _

Form 12: This form number conveys special information when used in conjunction with the Node entity (type number 134) in Finite

Element applications.

Refer to Fig. 3- 17(c) for notation. The matrix R and the vector T

are used to transform coordinate data from the ul, u2, u3

coordinate system to the x,y,z local system.

The ul, u2, u3 coordinate system has its origin at an arbitrary fixed

point

XOFFSET = r0sin 0osin 0O

YOFFSET = r0sin 0o cos 0O

ZOFFSET = rQ

cos 90

for r 0 = 0, take 0o = 0O = 0°

for 0o = 0° or 180°, take 0O = 0°

in the x,y,z coordinate system. The ul, u2, u3 system is the system

obtained by imposing orthogonal curvilinear coordinates onto the

x,y,z space which are the spherical coordinates (r, 9, 0) with

X = r sin 9 cos 0

Y = r sin 9 sin 0

Z = r cos 9

ro >0

049o^180°

O^0o<36O°

165
124 TRANSFORMATION MATRIX

and then constructing unit tangent vectors to the three curvilinear

coordinate curves at the given fixed point to serve as basis vectors.

Thus, the relationship between the ul, u2, u3 and the x,y,z local

coordinate systems is given by

sin0o cos0o cos0o cos0o

-sin0o ul XOFFSET XLOCAL

sin0o sin0o cos90

sin0o cos0o u2 + YOFFSET = YLOCAL

cos0o -sin0o 0 u3 ZOFFSET ZLOCAL

See, Kaplan, (KAPL52) or Hildebrand, (HILD76) for a discussion of orthogonal

curvilinear coordinate systems.

3.14.7 Directory Data

ENTITY TYPE NUMBER: 124

3.14.8 Parameter Data

Index Name TyPe Description

1 R 1

1

Real Top Row

2 R 12 Real

3 R 13 Real

4 T

1

Real

5 R21 Real Second Row

6 R22 Real

7 R23 Real

8 T2 Real

9 R31 Real Third Row

10 R32 Real

11 R33 Real

12 T3 Real

Additional Pointers as required (see 2. 2. 4. 4. 2).

166
125 - FLASH

3.15 Flash Entity

A flash entity is a point in the ZT=0 plane that locates a specific instance of a

particular closed area. That closed area can be defined in one of two ways.

First, it can be an arbitrary closed area defined by any entity capable of defining a closed area. The points of this entity must all lie in the ZT=0 plane. Second, it can be a member of a predefined set of flash shapes.

In the latter case, parameters 3 through 5 of the flash entity control the final

size of the flash. Figure 3-18 indicates the usage of those parameters for the

specific flash forms. Parameters 3 through 5 are ignored for form zero.

3.15.1 Directory Data

ENTITY TYPE NUMBER: 125

Form Meaning

0 defined by referenced entity

1 circular

2 rectangle

3 donut

4 canoe

3.15.2 Parameter Data

Index Name TyPe Description

1 X Real X reference of

flash

2 Y Real Y reference of

flash

3 DIM1 Real First flash sizing

parameter

4 DIM2 Real Second flash sizing

parameter

5 ROT Real Rotation of flash

about reference

point in radians

6 DE Pointer DE of referenced

entity or zero

Additional Pointers as required (see 2.2AA.2).

167
125 - FLASH

UJ

I-3Z0Q1

rO

DCo o _|

DC

O o Eo

crlu cr t- UJ 3 Z O z

LxO

CT

IxJ

UJ

DC

UJ

O

DCUJN

DCO < <

DC

UJ

UJo

UJ

_Jo

DCo

cn

_ CVJ z z o o

cn cn z z

UJ UJ 5 2 O Q

O

DC

O

CLLUOz

UJ

cr

UJ

cr z<o zo uuo X

I-oz

UJ<

tr

Ixl >o

cn 3tz o UJ u5

cn

Q

Q< cn ^x

z<X

UJz°xcr

_ CM ii <o

trUJo

cno

CL I

tro

Lx

OO

cn cn |_ Z 2 < Ixl UJ L_ X _ o o q tr

UJoz

UJ

tr

Lxl LxLU

tr

Lxl _JO

trO

O

cr

Lx LU O N

DC cr 1—

LU o

LU _i

cr I _j < < 3

_j

O Z

ZDO II ll cr— CVJ o Z z i o o — cn cn 2 z

LU z

LU

cr 2 2 o

Lx

QQ o

i—<

tr

Lxl

Lxl O

Lxl _JO

DCO

cn

l-zo

CL

Lxl Oz

Lxl ir

Lxl

Lxl cr

LU

_J


 z<0

LU

tr1

r\j

tro o

trLU

tro

LxLUmx

H-oz

UJ<X

II Z

LU

cn o i

i—

X < o

h- o o _j

cr

O

—

LU tt:z f o

cr

1—

X o zcn

Lx 3 Z

LU

O LU

CD 2 X cn °

1-

e>

IAN TO z Q LU

_l < cn

cr z

cn

X

z<

X< X

UJ

>- i% ii

CVI

ii Z z o o

cn

p z < LU 1-o Q cr

LU

_Joz<o

LU

tro

DCZ

UJo

cnzo

CLLU

<_> LU

trLU

UJ

tr

168

FIGURE

3-18

FLASH

ENTITIES
126 - RATIONAL B SPLINE CURVE

3.16 Rational B-Spline Curve Entity

The rational B-spline curve may represent analytic curves of general interest.

This information is important to both the sending and receiving systems. The

directory entry form number parameter is provided to communicate this

information. It should be emphasized that use of this curve form should be

restricted to communications between systems operating directly on rational Bspline curves and not used as a replacement for the analytic forms for

communication. For a brief description of a rational B-spline curves, see Section

4 of Appendix D.

If the rational B-spline curve represents a preferred curve type, the form number

corresponds to the most preferred type. The preference order is from 1 through

5 followed by 0. For example, if the curve is a circle or circular arc, the form

number is set to 2. If the curve is an ellipse with unequal major and minor axis

lengths, the form number is set to 3. If the curve is not one of the preferred

types, the form number is set to 0.

If the curve lies entirely within a unique plane, the planar flag (PROP1) is set to

1, otherwise it is set to 0. If it is set to 1, the plane normal (parameters

14+A+4K through 16+A+4K) contain a unit vector normal to the plane containing

the curve. These fields exist but are ignored if the curve is non-planar.

169
126 RATIONAL B SPLINE CURVE

If the beginning and ending points on the curve are identical, PROP2 is set to 1.

If they are not equal, PROP2 is set to 0.

If the curve is rational (does not have all weights equal), PROP3 is set to 0. If

all weights are equal to each other, the curve is polynomial and PROP3 is set to

1. The curve is polynomial since in this case all weights cancel and the

denominator sums to one (see Appendix D4).

If the curve is periodic with respect to its parametric variable, set PROP4 to 1, otherwise set PROP4 to 0.

3.16.1 Directory Data

ENTITY TYPE NUMBER: 126

Form Meaning

0 Form of curve must be determined from the rational B-spline

parameters.

1 Line

2 Circular arc

3 Elliptical arc

4 Parabolic arc

5 Hyperbolic arc

3.16.2 Parameter Data

Index Name TyPe Description

1 K Integer Upper index of sum. See

Appendix D

2 M Integer Degree of basis

functions

3 PROP1 Integer =0 - non-planar

= 1 - planar

4 PROP2 Integer =0 - open curve

= 1 - closed curve

5 PROP3 Integer =0 - rational

= 1 - polynomial

6 PROP4 Integer =0 - nonperiodic

= 1 - periodic

Let N=K-M+1 and let A=N+2M

170
126 RATIONAL B SPLINE SURFACE

7

•

T(-M) Real Knot Sequence

•

7+

A

T(N+M)

8+A W(0)

•

Real Weights

8+A+K

•

•

W(K)

9+A+K XO Real Control Points

10+A+K YO

11+A+K

•

ZO

•

•

• 9+A+4K

•

• XK

10+A+4K YK

11+A+4K ZK

12+A+4K V(0) Real Starting parameter value

13+A+4K V(l) Real Ending parameter value

14+A+4K XNORM Real Unit Normal (if curve is planar)

15+A+4K YNORM

16+A+4K ZNORM

Additional Pointers as required (see 2. 2. 4. 4. 2).

Software to convert between parametric spline curves or surfaces and the corresponding

rational B-spline curves or surfaces is available from the IGES office at the National

Bureau of Standards. Materials provided include a magnetic tape of Pascal source code, a

listing of the code, and accompanying documentation.

171
128 - Rational B-Spline Surface

3.17 Rational B-Spline Surface Entity

The rational B-spline surface represents various analytical surfaces of

general interest. This information is important to both the generating and

receiving system. The directory entry Form Number parameter is provided

to communicate such information. For a brief description of rational Bspline surfaces, see Section 6 of Appendix D..

If the rational B-spline surface represents a preferred surface type, the

form number corresponds to the most preferred type. The preference

order is from 1 through 9 followed by 0. For example, if the surface is a

right circular cylinder, the form number is set to 2. If the surface is a surface of revolution and also a torus, the form number is set to 5. If the

surface is not one of the preferred types, the form number is set to 0.

If, for each fixed value of the second parametric variable the resulting curves which are functions of the first parametric variable are closed, set PROP1 to 1; otherwise set PROP1 to 0. Similarly, if for each fixed value

of the first parametric variable the resulting curves which are functions of

the second parametric variable are closed, set PROP2 to 1; otherwise set PROP2 to 0.

If the surface is rational (does not have all weights equal) set PROP3 to 0.

If all weights are equal to each other, the surface is polynomial and PROP3

is set to 1. The surface is polynomial since in this case all weights cancel

and the denominator sums to one (see Appendix D4).

If the surface is periodic with respect to the first parametric variable, set PROP4 to 1; otherwise set PROP4 to 0. If the surface is periodic with

respect to the second parametric variable, set PROP5 to 1; otherwise set PROP5 to 0.

172
128 - Rational B-Spline Surface

3.17.1 Directory Data

ENTITY TYPE NUMBER: 128

Form Meaning

0 Form of the surface must be determined from the

rational B-spline parameters

1 Plane

2 Right circular cylinder

3 Cone

4 Sphere

5 Torus

6 Surface of revolution

7 Tabulated cylinder

8 Ruled surface

9 General quadric surface

Parameter Data

Index Name Type Description

1 K

1

Integer Upper index of first sum.

See Appendix D

2 K2 Integer Upper index of second sum.

See Appendix D

3 MI Integer Degree of first set of basis

functions

4 M2 Integer Degree of second set of

basis functions

5 PROP1 Integer = 1 Closed in first parametric variable

direction

=0 Not closed

6 PROP2 Integer = 1 Closed in second

parametric variable

direction

=0 Not closed

7 PROP3 Integer =0 Rational

= 1 Polynomial

8 PROP4 Integer =0 Non-periodic in first parametric variable

direction

= 1 Periodic in first parametric variable

direction

173
128 - Rational B-Spline Surface

9 PROP5 Integer =0 Non-periodic in second

parametric variable

direction

= 1 Periodic in second

parametric variable

direction

Let N1 = K1 - A = N1 + 2M1,Ml + 1, N2 = B = N2 + 2M2,K2 - M2 + 1,

, C = (K1 + 1) (K2 + 1)

10

• S(-Ml)• Real First knot sequence

10+A

•

S(N1+M1)

11+A T(-M2) Real Second knot sequence

1 1+A+B T(N2+M2)

12+A+B W(0,0) Real Weights

13+A+B W(1,0)

1 1+A+B+C W(K 1,K2)

12+A+B+C X(0,0) Real Control Points

13+A+B+C Y(0,0)

14+A+B+C Z(0,0)

15+A+B+C X(1,0)

16+A+B+C Y(1,0) Real Control Points

17+A+B-t-C Z(1,0)

9+A+B+4C X(K1,K2)

10+A+B+4C Y(K1,K2)

1 1+A+B+4C Z(K1,K2)

174
128 - Rational B-Spline Surface

Index Name Type Description

12+A+B+4C u(o) Real Starting value for first parametric direction

13+A+B+4C U(l) Real Ending value for first parametric direction

14+A+B+4C v(o) Real Starting value for second

parametric direction

15+A+B+4C V(l) Real Ending value for second

parametric direction

Additional Pointers as required (see 2. 2. 4. 4.2).

Software to convert between parametric spline curves or surfaces and the corresponding

rational B-spline curves or surfaces is available from the IGES office at the National

Bureau of Standards. Materials provided include a magnetic tape of Pascal source code, a

listing of the code, and accompanying documentation.

175
130 Offset Curve

3.18 Offset Curve Entity

The Offset Curve entity contains the data necessary to determine the

offset of a given curve C. This entity points to the base curve to be offset

and contains the offset distance and additional pertinent information. No

restriction is placed on the entity types of curves. Any parametric curve may be offset.

It is the intent of this Specification to limit the applicability of offsets to curves which are planar and slope continuous. The offset curve lies in the

plane which contains the base curve as follows:

let C denote a curve in definition space which is defined by r = r(t);

let T(t) denote the unit tangent at r(t); (See FAUX79)

let V be a unit vector normal to the plane which contains C.

Then the offset curve is a curve defined as:

0(t) = r(t) + f(s)*(V X T(t)) TT1 ^ t ^ TT2

a) if FLAG = 1, a uniform offset distance,

f (s) = D1

b) if FLAG = 2, an offset distance varying linearly,

f (s) = D1 + (D2 - Dl)*(s - TD 1)/(TD2 - TD1) with

case (i) PTYPE = 1

s = arc length along r from r(TTl) to r(t), D1 = the offset at arc length value TD1,

D2 = the offset at arc length value TD2

case (ii) PTYPE = 2

S =t,

D1 = the offset at parametric value TD1,

D2 = the offset at parametric value TD2

176
130 Offset Curve

c) if FLAG = 3, an offset distance defined by a function,

f(s) is the NDIM-th cordinate function of the curve

pointed to by DE2, with

case (i) PTYPE = 1

s = arc length along r from r(TTl) to r(t), case (ii) PTYPE = 2

s = t

Note that TT1 and TT2 must be chosen to be in the domain of

the base curve r(t).

3.18.1 Directory Data

ENTITY TYPE NUMBER: 130

3.18.2 Parameter Data

Index Name Type Description

1 DEI Pointer Pointer to curve entity to be offset.

2 FLAG Integer Offset distance flag:

1 = Single value offset,

uniform distance

2 = Offset distance varying

linearly

3 = Offset distance as a

specified function.

3 DE2 Pointer

or 0

Pointer to curve, one

coordinate of which

describes the offset as a function of its parameter.

(0 unless FLAG = 3) NDIM Integer Pointer of particular

coordinate of DE2 which

describes offset as a function of its parameter,

(only used if FLAG = 3)

177
130 Offset Curve

Index Name Type Description

5 PTYPE Integer Tapered offset type flag:

1 = Function of arc length

2 = Function of parameter

(only used if FLAG=2 or 3)

6 D1 Real First offset distance.

(only used if FLAG=1 or 2)

7 TD1 Real Arc length or parameter

value, depending on PTYPE,

of first offset distance,

(only used if FLAG=2)

8 D2 Real Second offset distance.

9 TD2 Real Arc length or parameter

value, depending on PTYPE,

of second offset distance,

(only used if FLAG=2)

10 VX Real X-component of unit vector

normal to plane containing curve to be offset.

11 VY Real Y-component of unit vector

normal to plane containing curve to be offset.

12 VZ Real Z-component of unit vector

normal to plane containing curve to be offset.

13 TT1 Real Offset curve starting

parameter value.

14 TT2 Real Offset curve ending

parameter value.

Additional Pointers as required (see 2. 2. 4. 4. 2).

Parameter data not required for a particular case should be given zero

values. For example, if the value of parameter 2 is not 3, then parameters

3 and 4 should be given zero values.

178
132 - CONNECT POINT

3.19 Connect Point Entity

A Connect Point Entity describes a point of connection for zero, one or more entities. These entities include those required in piping diagrams,

electrical and electronic schematics, and physical designs (e.g., printed

wiring board). The Connect Point Entity is referenced from either the

Network Subfigure Definition, Network Subfigure Instance, or the Flow

Associativity Instance; or it may stand alone in a file. The connect point

may be displayed by the receiving system using default display parameters

and/or symbol. Also see 2.5.2.

3.19.1 Directory Data

ENTITY TYPE NUMBER: 132

3.19.2 Parameter Data

Index Name lype Description

1 X Real X coordinate of the

connection point

2 Y Real Y Coordinate of the

connection point

3 Z Real Z coordinate of the

connection point

4 PTR Pointer Pointer to directory

entry of the display

symbol geometry

179
132 - CONNECT POINT

Index Name Iype Description

5 TF Integer Type flag

0 = not specified

1 = logical

2 = physical

6 FF Integer Function Flag:

0 = not specified

1 = electrical signal 2 = fluid flow path

7 C1D String Connect Point

Function Identifier

(e.g., Pin Number or Nozzle Label)

8 PTTCID Pointer Pointer to Text

Display Template

Entity for CID.

9 CFN String Connection Point

Function Name

10 PTTCFN Pointer Pointer to Text

Display Template

Entity for CFN

11 CPID Integer Unique Connect

Point Identifier

12 FC Integer Connect Point

Function Code:

0 = Unspecified

(default)

1 = Input

2 = Output

3 = Bidirectional

4 = Power

5 = Ground

13 SF Integer Swap Flag

0 = Connect point

may be swapped

(default)

1 = Connect point

may not be swapped

14 PSFI Pointer Pointer to "owner"

Network Subfigure

Instance, or Network

Subfigure Definition,

or zero.

Additional Pointers as required (see 2. 2. 4. 4.2).

180
134 - NODE

3.20 Node Entity

The node entity is a geometric point used in the definition of a finite element.

Directory entry field 7 points to a labeled definition coordinate system

Transformation Matrix. The form number of the Transformation Matrix indicates

the definition coordinate system type. Coordinate angles for the cylindrical and

spherical coordinate systems are specified in degrees.

3.20.1 Every node has a nodal displacement coordinate system associated with it. This

is form 10, 11, or 12 of the Transformation Matrix Entity which locates

translational and rotational directions for load, restraint and displacement

results. Again, the form number of the Transformation Matrix indicates the

coordinate system type.

The origin of the nodal displacement coordinate system is always the location of

the node. However, the orientation of the nodal displacement axes depends on

the location of the node and the type of displacement coordinate system being

referenced. Cartesian (Rectangular), cylindrical and spherical are the three

possible types.

If the displacement coordinate system is Cartesian, then the nodal displacement

axes are parallel to the respective referenced coordinate system. This is

illustrated in Figure 3- 19(a) Cartesian.

For the cylindrical type displacement coordinate system, the orientation of the

nodal displacement axes depends on the coordinate value of the node as defined

in the referenced displacement coordinate system. The nodal displacement axes

are respectively in the radial, tangential and axial directions as illustrated in Figure 3- 19(b) Cylindrical.

Finally, for spherical, the orientation of the nodal displacement axes depend on

both the 0 and 0 coordinates of the node as defined in the referenced

displacement coordinate system. The nodal displacement axes are respectively

in the radial, meridional and azimuthal directions as indicated in Figure 3- 19(c)

Spherical.

181
134 NODE

If a node lies on the polar axis of either the cylindrical or spherical coordinate

system, the nodal displacement axes are defined parallel to the referenced

displacement coordinate system axes. For cylindrical the first axis is the 9=0

axis and the third axis is the z axis. For spherical the first axis is the 0=0 axis

while the third axis is the 9=0 axis. The remaining axis of both systems is defined by the appropriate cross product of the previously defined axes.

3.20.2 Directory Data

ENTITY TYPE NUMBER: 134

Entity Label: Node Label (Optional)

Entity Subscript: Node Number (Required)

3.20.3 Parameter Data

Index Name TyPe Description

1 X/R/R Real First nodal coordinate

2 Y/9/9 Real Second nodal coordinate

3 Z/Z/0 Real Third nodal coordinate

4 NDCSP Pointer Pointer to the

Transformation Matrix

form 10, 1 1 or 12 which

defines the Nodal

Displacement Coordinate System entity.

Default (zero) is Global

Cartesian Coordinate

System.

Additional Pointers as required (see 2. 2. 4. 4. 2).

Figure 3-19 illustrates the definition of a node in the three coordinate systems.

182
134 - NODE

Z

fw\^

(X, Y,

I

CARTESIAN

FIGURE 3-19

CYLINDRICAL SPHERICAL

NODE DEFINITION IN EACH COORDINATE SYSTEM

183
136 - FINITE ELEMENT

3.21 Finite Element Entity

A finite element is defined by an element topology (i.e., node connectivity) along

with physical and material properties.

3.21.1 Table 3-1 lists the data to define the element topology. Figure 3-20 illustrates

the node connectivity for each element topology.

3.21.2 In Table 3-1 the element name is an English abbreviation or acronym describing

the element. The element topology type is an integer number which will appear

as the first parameter of the parameter data. The order is an integer identifying

the order of an edge where 0=not applicable, l=linear, 2=parabolic and 3=cubic.

The number of nodes from Table 3-1 will appear as the second parameter of the

finite element parameter data. A missing node in the connectivity sequence will have its corresponding pointer value equal to zero.

3.21.3 Directory Data

ENTITY TYPE NUMBER: 136

Entity Label: Element Label (Optional)

Entity Subscript: Element Number (Required)

3.21.4 Parameter Data

Index Name TyPe Description

1 ITOP Integer Topology Type.

2 N

1

Integer Number of Nodes defining Element. See

3.23.2.

3 DE Pointer Pointer to first node

defining element. See

• • .

3.23.2.

Nl+2 DE Pointer Pointer to last node

defining element

Nl+3 ETYP String Element type name

Additional Pointers as required (see 2. 2. 4. 4. 2).

184
136 - FINITE ELEMENT

TABLE 3-1 FINITE ELEMENT TOPOLOGY

ELEMENT DATA CHART

Element Data

Element Number Number Number

Element Topology Order of of of

Name Type Nodes Edges Faces

BEAM 1 1 2 1 0

LTRIA 2 1 3 3 1 PTRIA 3 2 6 3 1 CTRIA 4 3 9 3 1 LQUAD 5 1 4 4 1 PQUAD 6 2 8 4 1 CQUAD 7 3 12 4 1 PTSW 8 2 12 9 5 CTSW 9 3 18 9 5

PTS 10 2 16 12 6

CTS 11 3. 24 12 6

LSOT 12 1 4 6 4 PSOT 13 2 10 6 4 LSOW 14 1 6 9 5 PSOW 15 2 15 9 5 CSOW 16 3 24 9 5 LSO 17 1 8 12 6

PSO 18 2 20 12 6

CSO 19 3 32 12 6

ALLIN 20 1 2 1 0

APLIN 21 2 3 1 0

ACLIN 22 3 4 1 0

ALTRIA 23 1 3 3 0

APTRIA 24 2 6 3 0

ALQUAD 25 1 4 4 0

APQUAD 26 2 8 4 0

SPR 27 0 2 0 0

GSPR 28 0 1 0 0

DAMP 29 0 2 0 0

GDAMP 30 0 1 0 0 MASS 31 0 1 0 0

RBDY 32 0 2 0 0

TBEAM 33 1 3 1 0

185
FINITE ELEMENT

FIGURE 3-20 FINITE ELEMENT TOPOLOGY SET

BEAM

El=l,2

1 El

LTRIA - Linear Triangle

El =1,2 Fl=l,2,3

E2=2,3

E3=3,l

PTRIA - Parabolic Triangle

El=l,2,3 Fl=l,?,3,4,5,6

E2=3,4,5

E3=5,6,l

CTRIA - Cubic Triangle

El=l,2,3,4 FI =1,2, 3, 4, 5, 6, 7, 8,

9

E2=4,5,6,7

E3=7,8,9,l

LQUAD - Linear Quadrilateral

El=!,2 Fl=l,2,3,4

E2=2,3

E3=3,4

E4=4,l

PQUAD - Parabolic Quadrilaterial

El = 1,2,3 FI =1 ,2, 3, 4, 5, 6, 7,

8

E2=3,4,5

E3=5,6,7

E4=7,8,l

4 E3 3

E2

2

8 4

1 2

*

N
136 - FINITE ELEMENT

t

7. CQUAD - Cubic Quadrilateral

El=l,2,3,4

E2=4,5,6,7

E3=7,8,9,10

E4 = 10,ll,12,l

Fl = l, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12

9 8

61.

8. PTSW - Parabolic Thick Shell Wedge

El = l,2,3 E4=7,8,9 E7 = l,7

E2=3,4,5 E5=9,10,ll E8=3,9

£3=5,6, 1 E6=l 1,12,7 E9=5,ll

Fl= 1,2, 3, 4, 5,

6

F2=7,8,9,10,l 1,12

F3= 1,2, 3,9, 8,

7

F4=3,4,5,l 1,10,9

F5=5,6, 1,7,12, 1

1

11

9. CTSW - Cubic Thick Shell Wedge

El = l,2,3,4 £4 = 10,11,12,13

E2=4,5,6,7 E5=13, 14,15,16

E3=7,8,9,l £6 = 16,17,18,10

Fl = 1,2, 3, 4, 5, 6, 7, 8,

9

F2=10, 11, 12, 13, 14, 15, 16, 17, 18

F3= 1,2, 3, 4, 13, 12,1 1,10

F4 =4, 5, 6, 7, 16, 15, 14, 13

F5=7,8,9, 1,1 0,1 8, 17, 16

E7 = 1, 10

E8=4. 13 £9=7,16

IS

10 .

11 .

PTS - Parabolic Thick Shell

El = 1,2,3 E5=9,10, 1 1 E9=l,9

E2=3,4,5 E6=l 1,12,13 E10=3,ll

E3=5,6,7 E7=13,14,15 El 1 = 5,13

E4-7,8, 1 E8=15,16,9 E12=7,15

Fl= 1,2, 3, 4, 5,6,7,

8

F2=9, 10, 11, 12, 13, 14, 15, 16

F3=l,2,3,l 1,10,9 F5=5,6,7,15,14,13

F4 = 3,4,5,13,12,l 1 F6=7,8,l,9,16,15

CTS - Cubic Thick Shell

El = l,2,3,4 E5=13,14,15,16

E2=4,5,6,7 £6=16,17,18,19

E3=7,8,9,10 E7 = 19,20,21,22

E4 = 10,11,12,1 E8=22,23,24,13

Fl= 1,2,3,4,5,6,7,8,9,10,1 1,12

F2 = 13, 14, 1 5, 16, 17, 18, 1 9,20 ,2 1 ,22,23,24

F3= 1,2,3,4,16,15, 14,13

F4 =4, 5, 6, 7, 19,18, 17, 16 F5=7, 8, 9, 10, 22, 21, 20, 19

F6 = 1 0, 1 1,12,1,13,24,23,22

IS 14-

187

2 3 4
136 FINITE ELEMENT

12. LSOT - Linear Solid Tetrahedron

E 1 = 1,2 E4=l,4

E2=2,3 E5=2,4

E3=3,

1

E6 = 3,4

FI = 1,2,3

F2= 1,2,4

F3=2,3,4

F4=3,l,4

13. PSOT - Parabolic Solid Tetrahedron

El = l,2,3 E4=l,7,10

E2=3,4,5 E5=3,8, 10 E3=5,6,l E6=5,9,10

Fl = l,2,3,4,5,6

F2= 1,2, 3, 8, 10,7

F3=3,4,5,9,10,8

F4=5,6, 1,7, 10,9

3

14. LSOW - Linear Solid Wedge

E 1 = 1,2 E4=4,5

E2=2,3 E5 = 5,6

E3=3,l E6=6.4

F 1 = 1,2,3

F2=4,5,6

F3=l,2,5,4

F4=2,3,6,5

F5 = 3, 1,4,6

E7 = l,4

E8=2,5

E9 = 3,6

6

15. PSOW - Parabolic Solid Wedge

El = l,2,3 E4= 10,1 1,12 E7 =1,7,10

E2=3,4,5 E5= 12,13,14 E8=3,8,12

E3=5,6, 1 E6= 14,15,10 E9=5,9,14

Fl= 1,2, 3, 4, 5,

6

F2=10,l 1,12,13,14,15

F3= 1,2,3,8,12,1 1,10,7

F4=3,4,5,9,14,13,12,8

F5= 5,6, 1,7, 10, 15, 14,

9

74

16. CSOW - Cubic Solid Wedge

El = l,2,3,4 E4=16,17,18,19

E2=4,5,6,7 E5=19,20,21,22

E3=7, 8,9,1 E6=22,23,24, 16 Fl = 1,2, 3, 4, 5, 6, 7, 8,

9

F2= 16, 17,18, 19,20,2 1 ,22,23,24

F3= 1,2, 3, 4, 11, 14, 19, 18, 17, 16, 13, 10

F4=4, 5, 6, 7, 12, 15, 22, 2 1,20, 19, 14, 11 F5=7,8, 9, 1,10, 13, 16, 24, 23, 22, 15, 12

£7 = 1,10,13,16

188
136 - FINITE ELEMENT

17.

18.

19.

LSO - Linear Solid

E 1 = 1 ,

2

E5=5,6 E9=l,5

E2=2,3 E6=6,7 E10=2,6

E3=3,4 E7=7,8 El 1 = 3,7

E4=4,l

FU1,2,3,4

F2=5,6,7,8

F3=l,2,6,5

F4=2, 3,7,6

F5=3,4,8,7

F6=4,l,5,8

E8=8,5 E12=4,8

PSO - Parabolic Solid

El = l,2,3 E7=17,18,19

E2=3,4,5 E8=19,20,13

E3=5,6,7 E9=l,9,13

E4=7,8,

1

E10=3,10,15

£5=13,14,15 El 1=5,1 1, 17 E6=15,16,17

Fl= 1,2, 3, 4,5,6,7,

8

E 1 2=7 ,12,19

F2=13,14,15,16,17,18.,19,20

F3= 1,2,3, 10, 15, 14, 13,9

F4=3, 4, 5,1 1,17,16,15, 10

F5=5,6,7,l 2,19,18,17, 11 F6=7,8, 1,9, 13,20, 19, 12

CSO - Cubic Solid

El = l,2,3,4

E2=4,5,6,7

E3=7,8,9,10

E4=10, 1 1,12,1

£5=21,22,23,24

E6=24,25,26,27

£7=27,28,29,30

E8=30,31,32,21

E9=l,13,17,21

E10=4,14,18,24

El 1=7,15, 19, 27

E12=10,16,20,30

Fl = 1,2,3,4,5,6,7,8,9,10,1 1,12

F2=21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 3 1,32

F3= 1,2,3,4,14,18,24,23,22,21,17,13

F4=4, 5, 6, 7, 15, 19, 27, 26, 25, 24, 18, 14 F5=7,8, 9, 10, 16, 20, 30, 29, 28, 27, 19, 15

F6 = 10,l 1,12, 1,13, 17, 21, 32, 31, 30,20, 16

189
136 - FINITE ELEMENT

20. ALLIN - Axisymmetric Linear Line

El = 1,2 No Faces

21. APLIN - Axisymmetric Parabolic Line

El = 1,2,3 No Faces

22. ACLIN - Axisymmetric Cubic Line

El = l,2,3,4 No Faces

23. ALTRIA - Axisymmetric Linear Triangle

E 1 = 1,2

E2=2,3 No Faces

E3=3,i

24. APTR.IA - Axisymmetric Parabolic Triangle

El = l,2,3

E2 = 3,4,5 No Faces

E3=5,6,

1

3

25. ALQUAD - Axisymmetric Linear Quadrilateral

El = 1,2

E2=2,3

E3=3,4 No Faces

E4=4,l

26. APQUAD - Axisymmetric Parabolic Quadrilateral

E 1 = 1,2,3

E2 = 3,4,5

E3=5,6,7 No Faces

E4=7,8,

1

190
136 - FINITE ELEMENT

SPR - Spring

No edges or faces

GSPR - Grounded Spring ° ^(TO_V

' ||!'

o

rp o DAMP - Damper

a E—|n*

GDAMP - Grounded damper

MASS - Mass E

RBDY - Rigid Body

CE

TBEAM - three noded beam

(no faces)

El = 1,2 21
138 - Nodal Displacement and

Rotation

3.22 Nodal Displacement and Rotation Entity

The FEM Nodal Displacement and Rotation Entity is used to communicate finite

element post processing data. It contains the incremental displacements and

rotations expressed in radians for each load case and each node in the model. It also contains a pointer to a general note entity for a description of the load

cases. For each node it contains the node number identifier and the node DE

pointer. The node number identifier is equivalent to the node number in the

directory entry subscript field of the node entity.

3.22.1 Directory Data

ENTITY TYPE NUMBER: 138

3.22.2 Parameter Data

Index Name TyPe Description

1 NC Integer Number of analysis cases

2 GP1 Pointer Pointer to general

note that describes

the first analysis case

• • • .

• • • •

• • • •

1 + NC GPNC Pointer Pointer to general note that

describes the last analysis case

2 + NC NN Integer Number of nodes

3 + NC NO 1 Integer Node number

identifier for first node

4 + NC NP1 Pointer Pointer to Node

Directory Entry

192
138 - Nodal Displacement and

Rotation

Index Name TyPe Description

5 + NC X Real X-Incremental

translation

First Analysis case

6 + NC Y Real Y-Incremental

translation

7 + NC Z Real Z-Incremental

translation

8 + NC Rx Real Rx-Incremental

rotation

9 + NC Ry Real Ry-Incremental

rotation

10 + NC Rz Real Rz-Incremental

rotation

• 7*NC - 1 X Real X-Incremental

translation

Last analysis case

• Y Real Y-Incremental

translation

• Z Real Z-Incremental

translation

• Rx Real Rx-Incremental

•

•

•

•

rotation

• + NC + NONN Integer Node number

*(6*NC+2)node NN identifier for NNth

node

NPNN Pointer Pointer to Node

Directory Entry

X Real X-Incremental

translation

First analysis case

193
138 - Nodal Displacement and

Rotation

Index Name TyPe Description

Y Real Y-Incremental

translation

First analysis case

Z Real Z-Incremental

translation

First analysis case Rx Real Rx-Incremental

rotation

First analysis case Ry Real Ry-Incremental

rotation

First analysis case

10 + NC + (NN-l)*(6*NC+2)

Rz Real Rz-Incremental

rotation

First analysis case

• X Real X-Incremental

translation

Last Analysis case

• Y Real Y- " "

• Z Real Z- " "

• Rx Real Rx-Incremental

rotation

Last analysis case

• Ry Real Ry " "

2+NC +

NN(6*NC+2)

Rz Real RZ "

Additional Pointers as required (see 2. 2.4. 4. 2).

194
140 - OFFSET SURFACE

3.23 Offset Surface Entity

The offset surface is a surface defined in terms of an already existing

surface.

1. Let S=S(u,v) be a regular surface defined by this Specification

parametrized and oriented by N(u,v), a differentiable field of unit

normal vectors defined on the whole surface, and d a fixed non-zero

real number. An offset surface to S is a parametrized surface S(u,v)

given by:

0(u,v) = S(u,v) + d*N(u,v); ul ^ u 4 u2

vl 4 v v2

The base surface S(u,v) is referenced by a pointer in the parameter

data section, while N(u,v) is found from S(u,v) as defined below. The

value of d is provided as a parameter value in the parameter data

section.

2. To determine which one of the two orientations of the orientable

regular surface S(u,v) the offset surface will be used to define O,

define

dS dS

du 0 V

li° 5

x

0S|

II du 0 V |

In order to avoid confusion connecting the orientation of the base

surface S(u,v), an additional offset indicator is included. That

indicator shown in Figure 3-21 consists of the vector (Nx, Ny, Nz)

defined by

(Nx, Ny, Nz) = N(Um,Vm)/ | [ N(Um,Vm) | [

(This is the unit normal vector at the parameter values (Um,Vm))

195
U0 - OFFSET SURFACE

where, if the surface is bounded,

U1 + u2 vl + v2

Um = and Vm = 2 2

or, if the surface is unbounded,

Um = 0.0 and Vm = 0.0

This indicates the direction in which the offset distance, d, is measured

positive at (Um,Vm).

CAUTION: the vector (Nx,Ny,Nz) is just an indicator of the direction with

respect to the base surface S(u,v) where the offset distance, d, is measured

positively; this vector does not participate in the evaluation of the offset

surface as is evident from formula for O that defines the offset surface.

FIGURE 3-21 OFFSET SURFACE IN 3-D EUCLIDEAN SPACE

196
140 OFFSET SURFACE

3.23.1 Directory Data

ENTITY TYPE NUMBER: 140

3.23.2 Parameter Data

Index Name lY-P-g Description

1 Nx Real The x-coordinate of the offset

indicator N(Um, Vm).

2 Ny Real The y-coordinate of the offset

indicator N(Um,Vm).

3 Nz Real The z-coordinate of the offset

indicator N(Um,Vm).

4 d Real The distance by which the surface is normally offset on the side of the

offset indicator if d > 0 and on the

opposite side if d< 0.

3 DE Pointer Pointer to the surface entity to be

offset.

Additional Pointers as required (see 2. 2.4. 4. 2).

197
142 - CURVE ON PARAMETRIC SURFACE

3.24 Curve On A Parametric Surface Entity

The Curve on a Parametric Surface entity associates a given curve with a surface and identifies the curve as lying on the surface.

Let S = S(u,v) = ( x(u,v), y(u,v), z(u,v)

)

be a regular parametrized surface whose domain is a rectangle

defined by

D = ( (u,v)

| ul ^ u 4. u2 and vl ^ v ^ v2)

Let B = B(t) be a curve defined by

B(t) = (u(t),v(t)) for a ^ t 4 b

taking its values in D.

A curve C(t) on the surface S(u,v) is the composition of two mappings,

S and B defined as follows:

C(t) = SoB(t)

= S(B(t))

= S(u(t), v(t))

= ( x(u(t),v(t)) , y(u(t),v(t)) , z(u(t),v(t)) ) a ^ t ^ b

The curve B lies in the two dimensional space which is the domain of the

surface S. Therefore, the representation used for B which has been derived

from a curve defined in this Specification must be two dimensional: the X

and Y coordinates of this curve pointed to by BPTR are used.

The "Entity Use Flag" (DE field 9) of the entity B is set to 05, indicating

that B is in the parameter space of the surface. As a consequence of that,

B cannot be scaled and if a transformation matrix is to be applied on B it

has to map it within the parameter space D in which it resides.

198
142 - CURVE ON PARAMETRIC SURFACE

Hence, a curve on a parametric surface is given by:

(a) the mapping C and an indication that the curve lies on the surface

S(u,v),

and

(b) the mappings B and S whose composition gives the curve C.

A curve on a surface may have been created in one of a number of various

ways:

(a) As the projection on the surface of a given curve in model space in a prescribed way, for example, parallel to a given fixed vector.

(b) As the intersection of two given surfaces.

(c) By a prescribed functional relation between the surface parameters

"u" and "v".

(d) By a special curve, such as a geodesic, emanating from a given point

in a certain direction, a principal curve (line of curvature) emanating

from a certain point, an asymptotic curve emanation from a certain

point, an isoparametric curve for a given value, or any other kind of

special curve.

The parameter data section contains three pointers:

(a) A pointer to the curve from which B(t) is derived;

(b) A pointer to the surface S(u,v);

(c) A pointer to the mapping C(t).

It also contains:

(d) A flag to indicate how the curve was created;

(e) A flag to indicate which of the two alternate representations was preferred by the sending system.

199
142 - CURVE ON PARAMETRIC SURFACE

3.24.1 Directory Data

ENTITY TYPE NUMBER: 142

3.24.2 Parameter Data

Index Name Type Description

1

2

3

4

5

CRTN Integer Indicates the way the curve on the sur- face has been created:

0 = Unspecified.

1 = Projection of a given curve on the

surface.

2 = Intersection of two surfaces.

3 = Isoparametric curve, i.e. either a u-parametric or a v-parametric

curve. SPTR Pointer Pointer to the surface on which

the curve lies. B*PTR Pointer Pointer to the entity that contains the

definition of the curve C* in the parametric space (u,v) of the surface S. CPTR Pointer Pointer to the curve C.

PREF Integer Indicates preferred representation

in the sending system:

0 = Unspecified.

1 = SoB* is preferred.

2 = C is preferred.

3 = C and SoB* are equally preferred.

Additional pointers as required (see 2. 2. 4. 4. 2).

200
144 - TRIMMED (PARAMETRIC) SURFACE

3.25 Trimmed (Parametric) Surface Entity

A simple closed curve in the Euclidean plane divides the plane into two

disjoint open connected components; one bounded and one unbounded. The

bounded one is called the interior region to the curve (herein called,

"interior"). The unbounded component is called the exterior region to the curve (herein called, "exterior").

The domain of the trimmed surface is defined as the common region of the

interior of the outer boundary and the exterior of each of the inner

boundaries and includes the boundary curves. Note that the trimmed

surface has the same mapping S(u,v) as the original (untrimmed surface)

but different domain. The curves that delineate either the outer or the

inner boundary of the trimmed surface are curves on the surface S, and are

to be exchanged by means of the Curve on a Parametric Surface (Entity

Type 142).

Let S(u,v) be a regular parametrized surface, whose untrimmed domain is a rectangle D consisting of those points (u,v) such that a^u^b and c4v<d

for given constants a, b, c, and d with a<b and c<d. Assume that S takes

its values in three dimensional Euclidean space so that it can be expressed

as

x(u,v)

S=S(u,v) = y(u,v) for each ordered pair (u,v) in D.

_z(u,v)_

Also let the mapping S be subject to the following regularity

conditions:

It has continuous normal vector in the interior of D.

It is one-to-one in D.

There are no singular points in D, i.e., the vectors of the

first partial derivatives of S at any point in D are linearly

independent.

201
144 - TRIMMED (PARAMETRIC) SURFACE

Two types of simple closed curves are utilized to define the domain of the

trimmed (parametric) surface.

The first type is called the outer boundary. There is exactly

one. It lies in D, and in particular, it can be the boundary curve

of D.

The second type is called the inner boundary. There can be any

number of them including zero. The set of inner boundaries

satisfies two criteria;

1. The curves as well as their interiors are mutually disjoint.

2. Each curve lies in the interior of the outer boundary.

If the outer boundary of the surface being defined is the boundary of D and

there are no inner boundaries, then the trimmed surface being defined is, in

fact, untrimmed.

3.25.1 Directory Data

ENTITY TYPE NUMBER: 144

3.25.2 Parameter Data

Index Name TyPe Description

1 PTS Pointer Pointer to the surface entity that is to be

trimmed

2 N

1

Integer =0, if the outer boundary is the boundary of D.

= 1, otherwise.

3 N2 Integer This number indicates the number of simple

closed curves which constitute the inner

boundary of the trimmed surface. In case no

inner boundary is introduced, this is set equal

to zero.

3+N1 PTOl Pointer Pointer to the simple closed curve (Curve on a Parametric Surface Entity), that constitutes

the outer boundary of the trimmed surface.

202
144 - TRIMMED (PARAMETRIC) SURFACE

Index Name Type Description

4+N1 PTI1 Pointer Pointer to the first simple closed inner

boundary curve (Curve on a Parametric

Surface entity) according to some arbitrary

ordering of these entities.

•

•

3+N1+N2 PTIN2 Pointer Pointer to the last simple closed inner

boundary curve (Curve on a Parametric

Surface entity).

Additional pointers as required (see 2. 2.4. 4.2)

203
1 1
NON-GEOMETRY - General

4 NON-GEOMETRY

4.1 General

This section contains capabilities for representing non-geometry and includes:

o Annotation Entities o Structure Entities

Entity numbers from 200 through 499 are reserved for this Section. In addition, some non-geometric entities make use of entity type number 106

(copious data).

205
NON-GEOMETRY - Annotation Entities

4.2 Annotation Entities

4.2.1 Entity Type/Type Number.

The following entities are defined in this section:

Entity Type Number Entity Type

106

202

206

208

210

212

214

216

218

220

222

228

230

4.2.2 Construction.

Copious Data

Centerline

Section

Witness Line

Angular Dimension

Diameter Dimension

Flag Note

General Label

General Note

Leader (Arrow)

Linear Dimension

Ordinate Dimension

Point Dimension

Radius Dimension

General Symbol

Sectioned Area

Many annotation entities are constructed by using other entities. For

example, the dimension entities may have 0, 1, or 2 pointers to witness line

entities (a form of copious data), 0, 1, or 2 pointers to leader (arrow) entitites

and a pointer to a general note entity.

For some annotation entities, a witness line or leader may not exist. For

these cases the parameter data field pointer value can be set zero. If any

constructive entity exists, but its display is suppressed, it can be set to blank

status or, if allowed, the pointer value can be set to zero.

206
NON-GEOMETRY - Annotation Entities

4.2.3 Definition Space.

An annotation entity may be defined in XT, YT, ZT definition space (see

the discussion in Section 3.1) or in a two-dimensional space associated with

a Drawing Entity (type 404). In the case of XT, YT, ZT definition space, a transformation matrix is applied to locate the annotation entity within

model space.

Within the XT, YT, ZT definition space, subordinate entities to an

annotation entity may have different ZT displacements. For example,

within the linear dimension, a different ZT value may be found in each of: general note, leader, and witness lines (which are pointed to in the linear

dimension parameter data). An example showing the use of ZT

displacement (DEPTH) is shown in Figure 4-1.

While the option of having dimensions occupy different planes exists, it is expected that only a single plane will be used. The reason for its existence

is due to the structure of annotation entities. As each dimension may be

comprised of several subordinate entities, each subordinate entity by its definition has the ability to stand alone and may require its own ZT

displacement. When used in conjunction with other entities as a subordinate to a primary entity, it is likely, though not necessary, that

each ZT is identical.

207
NON-GEOMETRY - Annotation Entities

208
202 - ANGULAR DIMENSION

4.2.4 Angular Dimension Entity.

An angular dimension entity consists of a general note; zero, one, or two

witness lines; two leaders; and an angle vertex point. Figure 4-2 indicates

the construction used. Refer to Figure 4-3 for examples of angular

dimensions. If two witness lines are used, each is contained in its own

copious data entity.

Each leader consists of at least one circular arc segment w

: th an arrowhead

at one end. The leader pointers are ordered such that the first circular arc segment of the first leader is defined in a counterclockwise manner from

arrowhead to terminate point, and the first circular arc segment of the

second leader is defined in a clockwise manner. (Refer to 3.1.2 for

information relating to the use of the term counterclockwise).

4.2.4. 1 Section 4.2.10 contains a discussion of multi-segment leaders. For those

leaders in angular dimension entities consisting of more than one segment,

the first two segments are circular arcs with a center at the vertex point.

The second circular arc segment is defined in the opposite direction from the

first circular arc segment. Remaining segments, if any, are straight lines.

Any leader segment in which the start point is the same as the terminate

point is to be ignored. This convention arises to facilitate the definition of

the second circular arc segment such as in the bottom leader in Figure 4-2.

Example 1 in Figure 4-3 illustrates a leader with three segments.

209
202 - ANGULAR DIMENSION

IE

InO

<

III

2

v cnDh2Z

CO

UJCL

o o: <xu

UJUO

-JV-<

cru

2 >

I- UJ

LUX ZIH

—vtu 020

CLJ

<UJHcoa

<c

CJ

r=> cn

f—

CO

o<_>

=s2 •—

UJI CO

XLUO UJ

l-tDCL

<=J Oljcc cn K< <

in< »— i D-iin (S) —

o

2=

OOllJ <C

<-Jl

CC <— CM

O

UJ o

1 CT

XUJZ - Hfl3< iS)

u_

CE

yj

>

210

THE

ASSOCIATED

LEADERS
66.6463

202 - ANGULAR DIMENSION

211

FIG.

4-3

EXAMPLES

OF

THE

ANGULAR

DIMENSION

ENTITY
202 - ANGULAR DIMENSION

4. 2. 4. 2 Directory Data

ENTITY TYPE NUMBER : 202

4. 2.4.3 Parameter Data

Index Name Il£e Description

1 GN Pointer Pointer to general note

directory entry

2 W1 Pointer Pointer to first wit- ness line directory

entry or 0

3 W2 Pointer Pointer to second

witness line directory

entry or 0

4 XT Real Coordinates of ver- tex point

5 YT Real

6 R Real Radius of leader arcs

7 A1 Pointer Pointer to 1st leader

directory entry

8 A2 Pointer Pointer to 2nd leader

directory entry

Additional Pointers as required (see 2. 2. 4. 4. 2).

212
106, Forms 20,21 CENTERLINE

4.2.5 Centerline Entity

The centerline entity takes one of two forms. The first, as illustrated in Figure 4-4, Examples 1 and 2, appears as crosshairs and is normally used in conjunction with circles. The second type (Example 3) is a construction

between 2 positions.

The Centerline entities are defined as form 20 or 21 of copious data. The

associated matrix transforms the XT-YT plane of the centerline into model

space. The coordinates of the centerline points describe the centerline

display symbol. The display symbol is described by line segments where each

line is from

(X , Y , Z ), to (X , , Y .

,

n’ n’ n’ n+1’ n+1’ .) where n = 1,3,5, ...,N-1 n+i

4.2.5. 1 See section 3.5 for parameters of the Centerline Entity.

213
106, Forms 20,21 CENTERLINE

\

l ”7

/

/

/

y

Lil

_J

0L

<

X

LU

214

FIG.

4-4

EXAMPLES

OF

THE

CENTERLINE

ENTITY
206 - DIAMETER DIMENSION

4.2.6 Diameter Dimension Entity

A diameter dimension consists of a general note, one or two leaders, and an arc

center point. Refer to Figure 4-5 for examples of the diameter dimension

entity. The arc center coordinates are used for positioning the diameter

dimension line relative to the arc being dimensioned.

4.2.6.1 Directory Data

ENTITY TYPE NUMBER : 206

4.2. 6. 2 Parameter Data

Index Name Type

1 NE Pointer

2 A1 Pointer

3 A2 Pointer

4 XT Real

5 YT Real

Additional Pointers as required (see 2.2.4.4.2).

Description

Pointer to general

note directory entry

Pointer to first lead- er directory entry

Pointer to second

leader directory

entry or zero

Arc center coordinates

215
206 - DIAMETER DIMENSION

216

FIG.

A-5

EXAMPLES

OF

THE

DIAMETER

DIMENSION

ENTITY
208 - FLAG NOTE

4.2.7 Flag Note Entity

A flag note entity is label information formatted as shown in Figure 4-6. The

rotation angle overrides the general note rotation angle and placement.

Additional examples of the flag note entity are shown in Figure 4-7.

The flag note entity may be defined with or without associated leaders.

NOTE: Box outlined within flag illustrates bounds of text and should not be interpreted as a sub-symbol.

Figure 4-6 FLAG NOTE

4.2.7. 1 The flag note is constructed from information defined in the general note entity.

This data is the character height and number of characters. For this reason, no geometric definition is explicit within the definition of the flag note entity.

The following specifications apply to Figure 4-6.

217
208 - FLAG NOTE

Variables:

H = Height

L = Length

TL = Text Length

T = Tip Length

Formulas:

TL

H

L

T

CH = Character height

NC = Number of characters

(in general note)

A = Rotation angle in radians

(.8)(CH)(NC)+(.4)(CH)(NC- 1) (2)(CH)

(TL)+(.4)(CH)

(.5)(H)/TAN35°

Restrictions:

H shall never be less than .3 in. L shall never be less than .6 in. T shall never be less than .214 in.

218
208 - FLAG NOTE

219
208 - FLAG NOTE

4. 2.7.2 Directory Data

ENTITY TYPE NUMBER : 208

4. 2.7.3 Parameter Data

Index Name TyPe Description

1 XT Real Lower left corner

coordinate of the

2 YT Real flag

3 ZT Real

4 A Real Rotation angle in radians

5 DENOTE Pointer Pointer to general

note directory entry

6 N Integer Number of arrows

(leaders) or zero

7 DEI Pointer Pointers to associated leaders

6+N DEI Pointer Pointer to last leader

Additional Pointers as required (see 2. 2. 4. 4. 2).

220
210 - GENERAL LABEL

4.2.8 General Label Entity.

A general label entity consists of a general note with one or more associated

leaders.

Examples of general label entities are shown in Figure 4-8

4.2.8. 1 Directory Data

ENTITY TYPE NUMBER : 210

4.2.8.2 Parameter Data

Index Name Type Description

1 DENOTE Pointer Pointer to associated

general note

2 N Integer Number of leaders

3 DE Pointer Pointers to

• • •

associated leaders

N+2 DE

•

•

Pointer Pointer to last leader

Additional Pointers as required (see 2. 2.4. 4.2).

221
210 - GENERAL LABEL

222
212 - GENERAL NOTE

4.2.9 General Note Entity.

A general note entity consists of one or more text strings. Each text string

contains text, a starting point, text size, and angle of rotation of the text. Examples of general notes are shown in Figure 4-9. The FC value indicates the

font number and is an integer. Positive values are pre-defined fonts. Negative

values point to user defined fonts or modifications to a pre-defined font.

The following fonts will be defined:

0. Symbol Font (use no longer recommended)

1 . Standard Block

2. LeRoy

3. Futura

4. Fastfont

5. Calcomp

6. Comp 80

7. Micro-Film Standard

8. ISO Standard

9. DIN Standard

10. Military Standard

11. Gothic

12. News Gothic

13. Lightline Gothic

14. Simplex Roman

15. Italic

16. APL

17. Century Schoolbook

18. Helvetica

1001. Symbol Font 1 1002. Symbol Font 2

Fonts in the 1000 series display symbols mapped onto ASCII characters as shown

in Figures 4-10 and 4-11. They do not specify a character display font.

223
212 - GENERAL NOTE

224
212 - GENERAL NOTE

e>v

0 0

a (5 P P

' \ P ©

l 1

4

1 1 A A Q Q

a q

IB 2 2

B BR R b Ei r o

* # 3 3 C C S S c CJ s ©

$

4 4 D D

T T d a t m

X % 5 5 E E

U U e o u ©

& & 6 6

F F

V V f // V A

0 0

7 7 G G w W 9 /y w

( c

8 8 H H X X h / X 4

) D

9 9 I I

Y Y i ~Er y y

K * : •

• J J Z Z j z Y

4 + 5 •

• K K [ [

k C c

0 » < < L L

\ \ l _L

1

1

1

- — m =r M M ] ]

m ® ) }

• • > > N N

A /\ n 0

- —

/ / ? ?• 0 0 - — 0 O

FONT CODE 100 1

FIGURE 4~ 10

225
212 - GENERAL NOTE

71 0 0

« <5 P P

% \ P t

i I•

1 1 A A Q Q

a X q

• II 2 2 B B R R b

•

• r -a-

« + 3 3 C C S S c < s *•-

t o

4 4 D D T T d > t 0

X % 5 5 E E U U e A u e

& 8, 6 6 F F V V f V T

m m

7 7 G G

w W g X V 4-

( c8 8H H X X h — X UJ

) D9 9 I 1

—

1

Y Y i * y X

K * : •

• J J Z Z j S

z oc

4 + * •• K K

C i

—

i

k c 6

• • < < L L

\ \ l V

1

1 M

- — - = M M ] I

—

i

m A ) TT

• • > > N N

A A n «« -

/ / ? ?• 0 0 - — 0 X

FONT CODE 1002

FIGURE 4-11

226
212 - GENERAL NOTE

Font 1 does not have a defined display. Use of Font 1 implies the receiving

system may use any font which displays the appropriate ASCII characters. The

intent of this font is for usage when the actual display of the characters is not

critical for the application.

Font 0 is an old symbol font and should no longer be used. Figure 4 - 12 is a mapping symbol definition for font 0.

If the FC number is not sufficient to describe the font, a text font definition

entity may be used to define the font. If a text font definition is being used, the

negative of the pointer value for the directory entry of the text font definition

entity is placed in the FC parameter. The use of the values WT, HT, SL, A, and

text start point are shown in Figure 4-13.

Within definition space, the parameters for the text block are applied in the

following order (See Figure 4-14):

1) Define the box height (HT) and box width (WT).

The rotate internal text flag indicates whether the text box is filled with

horizontal text or vertical text. The box width is measured from the text

start point in the positive XT direction and the box height is measured in the positive YT direction from the text start point, before the rotation

angle (A) is applied.

2) The slant angle is then applied to each individual character. For horizontal

text it is measured from the XT axis in a counterclockwise direction. For

vertical text the slant angle is measured from the YT axis.

3) The rotation angle is then applied to the text block. This rotation is applied in a counterclockwise direction about the text start point. The

plane of rotation is the XT, YT plane at the depth ZSn (where ZSn is the

value given for the text start point).

227
212 - GENERAL NOTE

0 X 26 54 9 102 B 130 X 156 0

1 —• 27 UJ 55 — 103 C 131 Y 157 O

2 < 30 X

56 • 104 D 132 Z 160 ©

3 > 31 a 57 / 105 E 133 [

161

4 A 32 6

60 0 106 F 134 \ 162 ©

5 r~ 33 M 61

1 107 G 135 ]

163 ©

6 X 34 TT 62 2 1 10 H 136 A 164 CD

7 — 35 63 3 1 1 1 I

137 165 ©

10 36 + 64 4 1 12 J 140 \ 166 A

1 1 s

37 o 65 5 1 13 K 141 167 <J>

12 = 40 66 6 1 14 L 142 cp 170 P

13 V 41 1

• 67 7 1 15 M 143 EJ 171 Y

14 A 42 II 70 8 1 16 N 144 172 Y

15 43 # 71 9 1 17 0 145 o 173 C

16 z 44 $ 72 •• 120 P 146 // 174 1

17

t

45 % 73 •9 121 Q 147 /y 175 )

20 * 46 & 74 < 122 R 150 / 176

21 — 47

#

75 = 123 S 151 -BP 177 z

22 — 50 C 76 > 124 T 152

23 0

51 )

77 ?125 U 153 r\

24 e 52 * 100 © 126 V 154 i

25 T 53 + 10 1 A 127 W 155 ©

FIGURE 4-12 CHARACTER SET & OCTAL CODE FOR

FONT CODE ZERO

228
212 - GENERAL NOTE

4) The mirror operation is performed next. The value 1 indicates the mirror

axis is the (rotated) line perpendicular to the text base line and through the

text start point. The value 2 indicates the mirror axis is the (rotated) test base line.

Finally, the Transformation Matrix entity is used to specify the relative position of

definition space within model space.

The number of characters (NCn) must always be equal to the character count in its corresponding text string (TEXTn).

229
212 - GENERAL NOTE

U. P it) 5c F ce F

H

X

230

FIGURE

4-13

GENERAL

NOTE

TEXT

CONSTRUCTION
HORIZONTAL

TEXT

VERTICAL

TEXT

212 - GENERAL NOTE

tnn

tern

231

FIG.

H-m

GENERAL

NOTE

EXAMPLE

OF

TEXT

OPERATIONS
212 - GENERAL NOTE

4.2.9.

1

The graphical representation and recreation of notes with a special

structure are handled by the use of the Form Number in Field 15 of the

Directory Entry for this entity. A system to accommodate these notes is outlined below. Any strings after those specified by the form number are considered additional, appended strings that are not related in any particular manner to the previously referenced strings.

4. 2. 9.

2

In the event that a string necessary for the defined structure is not present

in the originating system's note, a null string shall be inserted in the

general note entity to take the place of the non-existent string to maintain

the structure of the data.

4. 2. 9.

3

Notes that contain fractional notation will be represented as mixed

numerals. This is done through the use of four consecutive strings

representing the whole number, the numerator, the denominator, and the

divisor bar. These are examples of the divisor bar string:

1H/ 1H- 2H— 1H

4.2. 9.

4

The following form numbers for the general note are used to maintain the

graphical representation of the originating system's note:

4.2.9.4.1 Form 0: Simple Note (default) - A general note of one or more strings

such that a text string is not related in any manner to another

string in the same general note entity.

4. 2. 9. 4.

2

Form 1: Dual Stack - A general note of two or more strings where the

first two are related in a manner such that they are both left

justified and the second string is displayed 'below' the first.

xxxxxx yyyyy

232
212 - GENERAL NOTE

4. 2. 9. 4. 3 Form 2: Imbedded Font Change - A general note of two or more strings

that is intended as a single string but was divided to accommodate

a font change in the string, xxxx yyy xxxx

4. 2. 9. 4. 4 Form 3: Superscript - A general note of two or more strings where the

second string is a superscript of the first string.

4. 2. 9.4. 5 Form 4: Subscript - A general note of two or more strings where the

second string is a subscript of the first string. xxxyyy

4. 2. 9. 4. 6 Form 5: Super-/Sub-script - A general note of three or more strings where

the second string is a superscript of the first string and the third

string is a subscript of the first string.

yyy

XXX

zzz

4.2. 9. 4. 7 Form 6: Multiple Stack/Left Justified - A general note where all strings are left justified to a common margin. These strings originated as a "paragraphed" note, xxxxxxxxxx

yyyyyyyyy zzzzzzzzzzz

4. 2. 9. 4. 8 Form 7: Multiple Stack/Center Justified - A general note where all strings are center justified to a common axis, xxxxxxx

yyyy zzzzzzz

233
212 - GENERAL NOTE

4.2. 9. 4. 9 Form 8: Multiple Stack/Right Justified - A general note where all strings are right justified to a common margin, xxxxxxxxxx

yyyyyyy zzzzzzzz

4.2.9.4.10 Form 100: Simple Fraction - A general note of four or more strings

where the first four strings define a mixed numeral as defined in 4. 2. 9. 3. yyy

XXzzz

4.2.9.4.11 Form 101: Dual Stack Fraction - A general note of eight or more

strings which represent two mixed numerals as defined in

4. 2. 9. 3. These mixed numerals are related such that the

fifth through the eighth strings are displayed below the first through the fourth strings respectively.

yy xx —

zz

.jj

11 —

kk

4.2.9.4.12 Form 102: Imbedded Font Change/Double Fraction - This general note

originated as a single string but was split to accommodate a

font change for a special character in the fifth string. This

is a general note of nine or more strings where the first and

sixth strings represent the whole number string of a mixed

numeral as defined in 4. 2.9. 3. The fifth string is a character

(or characters) that was set apart to accommodate the font

change.

yy jj xx — - ii —

zz kk

234
212 - GENERAL NOTE

4.2.9.4.13 Form 105: Super-/Subscript Fraction - A general note of twelve or more strings where the first, fifth, and ninth strings

represent the whole number string of a mixed numeral as defined in 4. 2.9. 3. The second and third mixed numerals are

the superscript and subscript respectively of the first mixed

numeral.

yy xx —

zz

.JJ

11 —

kk

ss

rr --

tt

235
212 - GENERAL NOTE

4.2.

9

.

5

Directory Data

ENTITY TYPE NUMBER : 212

4. 2. 9.6 Parameter Data

Index Name IlE£ Description

1 NS Integer Number of text strings in general note

2 NCI Integer Number of characters in first string (TEXT1) or

zero. The number of

characters (NCn) must

always be equal to the

character count of its corresponding text string

(TEXTn)

3 WT1 Real Box width

4 HT1 Real Box height

5 FC Integer or Pointer Font characteristic

(Default = 1)

6 SL1 Real Slant angle of TEXT1 in radians (pi/2 is the value

for no slant angle and is the default value)

7 A1 Real Rotation angle in radians for TEXT1

8 Ml Integer Mirror flag

0-no mirroring

1 - mirror axis is perpendicular to text base line

2 - mirror axis is text base line

9 VH1 Integer Rotate internal text flag

(0-text horizontal, 1-text

vertical)

10 XS1 Real First text start point

11 YS1 Real

236
212 - GENERAL NOTE

12 ZS1 Real Z depth from XT, YT

plane

13 TEXT1 String First text string

14 NC2 Integer Number of characters in second text string

1+NS*12 TEXTNS String Last text string

2+NS*12 NCNS Integer Number of characters in last text string

Additional Pointers as required (see 2.2AA.2)

237
214 LEADER (Arrow)

4.2.10 Leader (Arrow) Entity.

A leader consists of one or more line segments except when the leader is part

of an angular dimension (see 4.2.4). The first segment begins with an arrowhead. Remaining segments successively link to a presumed text item.

An individual segment is assumed to extend from the end point of its predecessor in the segment list to its defined end point. Examples of leaders are shown in Figure 4-15.

In the use of angular, diameter, and linear dimension, there are instances

where the text is exterior to the line or arc lying between the two arrows. In these situations, it remains the case that the appearance of two arrows

implies the use of two leaders. These are formed by dividing the line or arc

lying between the two arrows into two non-overlapping segments. Refer to Figure 4-16.

Some leaders (for example, the leader involved with the radius dimension in Figure 4-16) give the appearance of locating an arrow interior to a segment.

There are two overlapping segments. The first segment begins at the arrow

and, in the radius dimension example, ends at the center of the arc or circle

being dimensioned. The second segment then retraces the first in the

opposite direction and extends it. Leaders of this type for other types of

dimensions are constructed similarly. For cases involving angular dimension,

the first two segments are arcs.

4.2.10.1 Forms. There are eleven arrowhead types defined (see figure 4-17) and

selection is made by entering the form number in directory entry field 15.

238
214 - LEADER (Arrow)

\

\

/

Il

II

I

V)

111 |

_l 5

Ol

°

1 ?

2 !

<

in

i a*

ID

239
EXAMPLES

OF

LEADERS

INTERNAL

TOA

DIMENSION

214 - LEADER (Arrow) A/ \

V)c

Ulo<

Ul o

mlz

fc

g < § u

-1

III in s

00 Ik o Ul

a z o (A Ui < Ul * — nu

UlH o>

-1 < JC

in Z -J< Ul -J M otn

in < Q it. in D tr W UJ < o o o mmm o CEUJ Q > u UJZ U o Q o UJ <in z 2 Ui< < -i O

03 i U.

in in

l.h

tu o H oz

ID CQ »- Z hO z — ZL -J o

-1 o 0. otr

0l Q.UJ a X “ z OH

K in o cco U CO u Q Ul z>- <

Ui

H in

H CD Ul

-1 1 1 1

111 z < o o

»- <

240

FIG.

<1-16

STRUCTURE

OF

LEADERS

INTERNAL

TOA

DIMENSION
214 - LEADER (Arrow)

AD2

FORM I* WEDGE

FORM 2: TRIANGLE

1

AOI

AD2

AD!

FORM 3: FILLED TRIANGLE

FORM 4: NO ARROWHEAD

FORM 5: CIRCLE

R --ADI

ADI.AD2

:o

FORM 6: FILLED CIRCLE

FORM 7* RECTANGLE

ADI.AD2

T AD2

i—10

|

I—1 h^—ADI

FORM 8* FILLED RECTANGLE AD2_

FORM 9* SLASH

FORM 10* INTEGRAL SIGN

FORM II* OPEN TRIANGLE

i

ADI

T-'t I H ADI

L AD2

rR'R 1 j AD2

rn

ADI

ADI

HOTEs INDICATES ORIGIN OCH, YH) AND IS NOT PART OF ARROWHEAD

FIG. 4-17 ARROWHEAD DEFINITIONS

241
214 - LEADER (Arrow)

4.2.10.2 Directory Data

ENTITY TYPE NUMBER:: 214

4.2.10.3 Parameter Data

Index Name IX£e Description

1 N Integer Number of segments

2 ADI Real Arrowhead height

3 AD2 Real Arrowhead width

4 ZT Real Z depth

5 XH Real Arrowhead coordinates

6 YH Real

7 X Real Segment tail coordinate pairs

Y Real

6+2N Y Real Last Segment

Coordinate

Additional Pointers as required (see 2. 2. 4. 4. 2).

242
216 - LINEAR DIMENSION

4.2.1 1 Linear Dimension Entity.

A linear dimension consists of a general note; two leaders; and zero, one or two witness lines. Refer to Figure 4-18 for examples of linear dimensions.

4.2.11.1 Directory Data

ENTITY TYPE NUMBER : 216

4.2.11.2 Parameter Data

Index Name lX2£ Description

1 DENOTE Pointer Pointer to general note directory entry

2 DEARRW1 Pointer Pointer to first leader directory

entry

3 DEARRW2 Pointer Pointer to second leader directory entry

4 DEWIT 1 Pointer Pointer to witness line directory entry, 0 if not defined

5 DEWIT2 Pointer Pointer to witness line directory entry or 0

Additional Pointers as required (see 2. 2.4. 4.2).

243
216 - LINEAR DIMENSION

244
218 - ORDINATE DIMENSION

4.2.12 Ordinate Dimension Entity.

The ordinate dimension entity is used to indicate dimensions from a common

base line. Dimensioning is only permitted along the XT or YT axis.

4.2.12.1 An ordinate dimension consists of a general note and a witness line or leader.

The values stored are pointers to the directory entry for the associated note

and witness line. Examples of ordinate dimensions are shown in Figure 4-19.

4.2.12.2 Directory Data

ENTITY TYPE NUMBER : 218

4.2.12.3 Parameter Data

Index Name Type Description

1 DENOTE Pointer Pointer to general note

directory entry

2 DEWIT Pointer Pointer to witness line directory entry or leader directory

entry

Additional Pointers as required (see 2. 2. 4. 4. 2).

245
218 - ORDINATE DIMENSION

246
220 - POINT DIMENSION

4.2.13 Point Dimension Entity.

A point dimension consists of a leader, text, and an optional circle or hexagon

enclosing the text.

4.2.13.1 The leader will always contain three segments, and its first and last segments

are always horizontal or vertical. If a hexagon encloses the text, it will be

described by a Composite Curve entity. If a circle or hexagon does not

enclose the text, the last segment of the leader will be horizontal and it will

underline the text.

4.2.13.2 Examples are shown in Figure 4-20.

4.2.13.3 Directory Data

ENTITY TYPE NUMBER :220

4.2.13.4 Parameter Data

Index Name Type Description

1 DEI Pointer Pointer to general note di- rectory entry

2 DE2 Pointer Pointer to leader directory

entry

3 DE3 Pointer Pointer to circular arc, com

posite curve, or 0.

Additional Pointers as required (see 2.2.4.4.2).

247
220 POINT DIMENSION

248

FIG.

i(-20

EXAMPLES

OF

THE

POINT

DIMENSION

ENTITY
222 - RADIUS DIMENSION

4.2.14 Radius Dimension Entity.

A radius dimension consists of a general note, a leader, and an arc center

point, (XT, YT). Refer to Figure 4-21 for examples of radius dimensions.

4.2.14.1 The arc center coordinates are used for positioning the radius dimension line

relative to the arc being dimensioned.

4.2.14.2 Directory Data

ENTITY TYPE NUMBER: 222

4.2.14.3 Parameter Data

Index Name IXE£ Description

1 DEN Pointer Pointer to general note di- rectory entry

2 DEP Pointer Pointer to leader directory

entry

3 XT Real Arc center coordinates

4 YT Real

Additional Pointers as required (see 2. 2.4. 4.2).

249
222 - RADIUS DIMENSION

250

FIG.

i|-21

EXAMPLES

OF

THE

RADIUS

DIMENSION

ENTITY
106, Forms 31-38 SECTION

4.2.15 Section Entity.

A section entity is defined as a copious data entity (Type 106 forms 31 to 38).

The form number describes how the data are to be interpreted. These

descriptions are included for compatability with previous versions of the

specification. The Sectioned Area Entity (Type 230) provides a more

compact method for transferring this information.

4.2.15.1 The point data contains a list of points (Xn, Yn), n=l, 2, . . . , N, (The Z

value is constant and N is an even integer.)

The display of the lines consists of solid line segments between the points

(Xn,Yn,Z) and (Xn+l,Yn+l,Z) where n = 1,3,5, ... N-l.

A portion of collinear line segments which appear to be a dashed line shall

consist of point pairs for each dash.

4.2.15.2 The defined line patterns are described below and illustrated in Figure 4-22.

(ANSI79).

Form number

31

Description

Parallel line segments from section edge to edge.

(Cast or malleable iron and general use for all materials)

32 Parallel line segments in pairs with a gap between

pairs. (Steel)

33 Alternating pattern of a solid line and a set of

collinear dash segments. (Bronze, brass, copper, and

compositions)

34 Parallel lines in quadruples with a gap between

groups. (Rubber, plastic, and electrical insulation)

251
106, Forms 31-38 SECTION

252

FIGURE

4-22

Examples

of

the

Section

Entity
106, Forms 31-38 SECTION

Form number

35

36

37

38

Description

Triples of parallel lines consisting of two solid lines

and a set of. col linear dash segments between them

with a gap between triples. (Titanium and

refractory material)

Parallel sets of collinear dash segments. (Marble,

slate, glass, porcelain)

Two perpendicular sets of parallel lines. (White

metal, zinc, lead, babbitt, and alloys)

Two perpendicular sets of lines with the principal

set solid from edge to edge and the second set consisting of collinear dash segments alternating on

the solid lines. (Magnesium, aluminum, and

aluminum alloys)

See Section 3.5 for parameters of the Section Entity.
228 - GENERAL SYMBOL

4.2. 1 6 General Symbol Entity.

A general symbol entity consists of a general note} one or more geometric

entities which define a symbol; and zero, one or more associated leaders.

Examples of general symbol entities are shown in Figure 4-23.

Any geometric entity used to create the symbol will have a subordinate

entity switch of 01 and an entity use flag of 01 in field 9 of its Directory

Entry section.

4.2.16.1 Directory Data

ENTITY TYPE NUMBER: 228

4.2.16.2 Parameter Data

Index Name Jype Description

1 DENOTE Pointer Pointer to associated general

note

2 N Integer Number of pointers to geometry

3 GPNT1 Pointer Pointer to defining geometry

N+2 GPNTN Pointer

N+3 L Integer Number of Leaders or zero

N+4 LPNT1 Pointer Pointers to associated

leaders

N+3+L LPNTL Pointer

Additional Pointers as required (see 2. 2. 4. 4. 2).

254
228 - GENERAL SYMBOL

FIGURE 4-23 GENERAL SYMBOL ENTITIES

255
230 - SECTIONED AREA

4.2.17 Sectioned Area Entity

A sectioned area is a portion of a design which is to be filled with a pattern

of lines. It consists of a pointer to a boundary curve, a specification of the

pattern of lines, the coordinates of a point on the lines, the distance between

lines, the angle between the lines and the X-axis of the definition space, and

the specification of any enclosed boundary curves (islands).

4.2.17.1 The XT and YT coordinates, which may be specified, indicate a location

which is on one of the lines. This point allows applications which require

specific placements of the lines to constrain them appropriately. If not

specified, i.e., indicated by default, the lines need only be within the

bounding curve.

4.2.17.2 The angle of the lines has a default value of pi/4, measured in radians.

4.2.17.3 The line pattern is specified according to predefined definitions illustrated in Figure 4-24.

4.2.17.4 Directory Data

ENTITY TYPE NUMBER: 230

4.2.17.5 Parameter Data

Index Name TyPe Description

1 BNDP Pointer Pointer to boundary curve-a single

closed curve or a composite curve

2 PATRN Integer Line pattern code

3 XT Real X coordinate through which a line

should pass

4 YT Real Y coordinate through which a line should pass

5 ZT Real Z depth of lines

6 DIST Real Normal distance between adjacent

lines

256
230 - SECTIONED AREA

7 ANGLE

8 N

9 ISLPT1

Real Angle measured in radians

from the XT axis to the

lines of the sectioning

Integer Number of island curves or zero

Pointer Pointer to a boundary curve for an

island

8+N ISLPTN Pointer Pointer to last boundary curve for an island

Additional pointers as required (see 2. 2. 4. 4.2).

257
230 SECTIONED AREA

LINE PATTERN CODES

FIGURE 4-24 SECTION LINE PATTERNS

258
106, Form MO - WITNESS LINE

4.2.18 Witness Line Entity.

A witness line is a form number 40 of a copious data block that contains one or more straight line segments associated with drafting entities of

various types. Each line segment may be visible or invisible. Refer to Figure 4-25 for examples.

4.2.18.1 If the witness line is suppressed, this is indicated by a 0 in the pointer

field of the drafting entity pointing to a witness line, or by setting the

blank status of the directory entry of the copious data entity for the

witness line.

4.2.18.2 Within the copious data, there will be the location from which the

witness line gap must be maintained. This point is indicated in the

figure as PI. The location will be the first point in the copious data.

PI will be coincident with the geometry being dimensioned or equal to P2 when the location of the geometry is unknown. Note: for those

annotation methods that do not allow drafting entities to be displaced

from the plane of annotation, coincident with the geometry indicates

that a line normal to the plane of annotation connects PI and the point on the geometry being dimensioned. Note that all points must be

collinear, and that the number of points will be odd and at least 3 (3, 5,

7, . . . ), with alternating blank and displayed segments. The examples

in Figure 4-25 show the blanking of segments and the order of points

stored in the copious data.

4.2.18.3 See Section 3.5 for parameters of the Witness Line Entity.

259
106, Form 40 - WITNESS LINE

260

FIGURE

4-25

EXAMPLES

OF

THE

WITNESS

LINE

ENTITY
NON-GEOMETRY Structure Entities

4.3 Structure Entities

4.3.1 Entity Type/Type Number

The following entities are defined in this section:

Entity Type Number Entity Type

302

304

306

305

310

312

314

320

402

404

406

408

410

412

414

416

418

420

600-699 or 10000-99999 as specified by user

Associativity Definition Entity

Line Font Definition Entity

MACRO Definition Entity

Subfigure Definition Entity

Text Font Definition Entity

Text Display Template

Color Definition

Network Subfigure Definition

Associativity Instance Entity

Drawing Entity

Property Entity

Singular Subfigure Instance Entity

View Entity

Rectangular Array Subfigure Instance Entity

Circular Array Subfigure Instance Entity

External Reference

Nodal Load/Constraint

Network Subfigure Instance

MACRO Instance Entity

261
302 - ASSOCIATIVITY DEFINITION

4.3.2 Associativity Definition Entity.

The associativity definition entity permits the preprocessor to define an

associativity schema. That is, by using the associativity definition, the

preprocessor defines the type of relationship. It is important to note that

this mechanism specifies the syntax of such a relationship and not the

semantics.

4.3.2. 1 Schema. The definition schema allows the specification of multiple groups of

data which are called classes. A class is considered to be a separate list, and

the existence of several classes implies an association among the classes as well as among the contents of each class.

For each class, the schema has provision to specify whether or not back

pointers are required. A back pointer being required implies that an entity

which is a member of this associativity (when it is instanced) has a pointer to the directory entry of the associativity instance in its back pointer parameter

section.

The provision in the schema to specify whether or not a class is ordered is used to state whether the order of appearance of entries in the class is

significant.

In the schema, "ENTRIES" are the members of the class. However, each

entry could be composed of several items. If multiple items are required,

they will be ordered. For example, if the entries were locations, each entry

might have three items to specify X, Y, and Z values.

The associativity definition will fix the number of classes for an associativity

and the number of items per entry in a particular class. Each associativity

instance will have a variable number of entries per class. In order to help

decode instances of the definition, each item is specified as a pointer (to an

entity directory entry) or a data value.

262
302 - ASSOCIATIVITY DEFINITION

4. 3.2.2 Form. Two kinds of associativity are permitted within the file. Pre-defined

associativities will have form numbers in the range of 1 to 5000 and are

defined in 4. 3. 3. 3. The second kind of associativity is defined in the file by a

preprocessor (Form numbers 5001-9999). These definitions appear once in the

file for each form of associativity defined, and allow the preprocessor to fill

in the definition according to a schema which defines the details of the

associativity.

The definition includes the associativity form, the number of class definitions, the number and type of items in each entry, and whether back pointers

(from the entity to the associativity) are required. Each set of values (BP,

Order, N, and Item type) is considered a class. See 4. 3. 3. 3.1 for a complete

example of associativity.

4. 3. 2. 3 Directory Data

ENTITY NUMBER : 302

4. 3. 2. 4 Parameter Data

Index Name JXpe Description

1 K Integer Number of class definitions

2 BP1 Integer 1- back pointers required

2- back pointers not required

3 OR 1 Integer

1-

ordered class

2-

unordered class

4 N

1

Integer Number of items per entry

5 IT 1(1) Integer

1-

pointer to a directory entry

2-

value

3-

parameter is a value or a

pointer

. if parameter £ 0 it is a value

4+N

1

if parameter < 0 it is a pointer

The items in parameters 2 through 4+N1 are repeated for each of the K classes.

263
402 - ASSOCIATIVITY INSTANCE

4.3.3 Associativity Instance Entity.

Each time an associativity relation is needed in the file an associativity

instance entity is used.

The form number of the associativity instance will identify the meaning of

the entity. If the form number is between 1 and 5000, the definition is specified as described in 4. 3. 2. 2. If the form number is between 5001 and

9999, an associativity definition will occur in the file and the structure field

of the instance (DE field 3) will contain a pointer to the directory entry of

the associativity definition.

Each entity that is a member of an associativity instance can contain a back

pointer to the associativity instance (see 2. 2. 4. 4. 2).

The parameters K and Nl, N2, ...NK are specified in the associativity

definition, (see 4. 3. 2.4)

4.3.3. 1 Directory Data

ENTITY TYPE NUMBER :402

i.2 Parameter Data

Index Name TyPe Description

1 NE1 Integer Number of class one entries

2 NE2 Integer Number of class two entries

K NEK Integer Number of class K entries

264
402 - ASSOCIATIVITY INSTANCE

For K classes with (NE1,...,NEK) entries

with (Nl, . . . , NK) items per entry

Index Name Jype Description

K + 1 11,1,1 Variable Class 1, Entry 1, Item 1

. Item 2

Variable Item Nl

Variable Entry 2, Item 1

Variable Item Nl

Variable Entry NE1, Item 1

• Item Nl

12,1,1 Variable Class 2, Entry 1, Item 1

Variable Item N2

Variable Entry 2, Item 1

• Item N2

• Variable Entry NE2, Item N2

IK, 1,1 Variable Class K, Entry 1, Item

1 X IK,NEK,NK Variable Class K, Entry NEK,

Item NK

Additional Pointers as required (see 2. 2. 4. 4. 2)

265
402, Form 1 GROUP ASSOCIATIVITY

4. 3. 3. 3 Pre-defined Associativities . As defined in 4. 3. 2. 2, the associativity definition

entity will only occur for Form Numbers 5001 through 9999. The following

paragraphs contain the definitions of the pre-defined associativities as they

would appear if they were defined by a user. Also included in this Section are the descriptions of each associativity's parameters in a manner similar to other entities in this Specification.

4.3.3.3.1 FORM NUMBER: 1 Group

The Group Associativity allows a collection of a set of entities to be

maintained as a single, logical entity. Figure 4-26 is an example.

There are four form numbers which specify Group associativities:

Form Number Description

1 Unordered group with backpointers required

7 Unordered group with backpointers not required

14 Ordered group with backpointers required

15 Ordered group with backpointers not required

The first (Form=l) is defined here; the others are defined in subsections

4. 3. 3. 3. 6 (Form=7), 4.3.3.3.10 (Form = 14), and 4.3.3.3.11 (Form = 15),

respectively.

DEFINITION

Index

1

2

3

4

5

Set Value

1

1

2

1

1

Meaning

One class

Back pointers required

Unordered

One item per entry

The item is a pointer

266
402, Form 1 - GROUP ASSOCIATIVITY

DESCRIPTION

Directory Data

ENTITY NUMBER: 402

FORM NUMBER: 1

Parameter Data

Index Name

1 N

2 DE

3 DE

I^pe

Integer

Pointer

Pointer

Description

Number of entries

Pointer to entity 1

Pointer to entity 2

N+l DE Pointer Pointer to entity N

Additional pointers as required (see. 2.2AA.2).

267
ASSOCIATIVITY

INSTANCE

402 Form 1 GROUP ASSOCIATIVITY

T—

I

268

FIGURE

4-26

ASSOCIATIVITY

INSTANCE

AND

ENTITIES
402, Form 2 - EXTERNAL LOGICAL

REFERENCE

4. 3. 3. 3. 2 FORM NUMBER: 2 External Logical Reference File Index

The External Logical Reference File Index appears in one file which contains

references from another file. It contains a list of the symbolic names used by

the referencing files and the DE pointers to the corresponding definitions

within the referenced file. See section 2.5.4 and the External Reference

Entity (type 416) for more detail.

DEFINITION

Index Set Value Meaning

1 1 One class (externally

referenced entities)

2 2 Backpointers not required

3 2 Unordered list of entries in a

class

4 2 Number of items in an entry

5 2 First item is a value

(External Reference Entity

Symbolic Name)

6 1 Second item is a pointer

(Internal Entity DE Pointer)

DESCRIPTION

Directory Data

ENTITY NUMBER: 402

FORM NUMBER: 2

Parameter Data

Index Name TXPe Description

1 N Integer Number of Index Entries

2 NAME1 String External Reference Entity

Symbolic Name

3 PTR

1

Pointer Internal Entity DE Pointer

269
402, Form 3 VIEWS VISIBLE

2N NAMEN String Last External Reference

Entity Symbolic Name

2N+1 PTRN Pointer Last Internal Entity DE

Pointer

Additional Pointers as Required (see 2. 2.4. 4. 2)

4.3. 3. 3.3 FORM NUMBER : 3 Views Visible

When an entity is to be displayed in a single view, a pointer to that view

entity is entered in parameter 6 of the entity's DE.

If an entity is to be displayed in more than one view, parameter 6 of its DE

contains a pointer to an instance of a Form 3 associativity. This form of the

associativity contains two classes of information. The first class contains the

number of views visible followed by pointers to each of the view entities

visible in the specific associativity instance. The second class contains the

number of entities whose display is specified by this instance, followed by

pointers to each of the entities.

DEFINITION

Index Set Value Meaning

1

2

3

4

5

6

7

8

2

Class 1

1

2

1

1

Class 2

2

2

1

Two classes

Back pointers required

Unordered

One item per entry

Item is a pointer

(to view entity)

Back pointers not required

Unordered

9 1

270

One item per entry

Item is a pointer

(to other entity)
402, Form 3 VIEWS VISIBLE

DESCRIPTION

Directory Data

ENTITY TYPE NUMBER: 402

FORM NUMBER: 3

Parameter Data

Index Name TyPe Description

1 N1 Integer Number of views visible

2 N2 Integer Number of entities displayed

in these views

3 DEVI

•

Pointer

•

Pointer to view entity

•

Nl+2

•DEVN1•

Pointer

Nl+3 DEI Pointer Pointer to entity whose display is being specified by this

• #

associativity instance

•

N1+N2+2 DEN2 Pointer Pointer to entity N2

Additional pointers as required (see 2. 2.4. 4.2).

271
402, Form 4 - VIEWS VISIBLE,

COLOR, LINE WEIGHT

4. 3. 3. 3. 4 FORM NUMBER: 4 Views Visible, Color, Line Weight

This associativity is an extension of Form Number 3. For those entities that are visible in multiple views, but must have a different line font, color

number, or line weight in each view, there will be an occurrence of the

associativity instance Form Number 4.

In the parameter data portion of the associativity instance, the parameter N1

will indicate the number of blocks containing the view visible, line font, color

number, and line weight specifications. Each block will contain a pointer to the view entity, a line font value or 0, a pointer to a line font definition

entity if the line font value was 0, a color value or pointer to a color

definition entity, and a line weight value. Parameter N2 will contain the

number of entities which are members of this associativity (i.e., entities

which have this particular display characteristic).

Note that N2 may often be 1. If more than one entity appears in Class 2 the

complete set of display characteristics in Class 1 apply to each entity in Class 2.

DEFINITION

Index Set Value Meaning

1 2 Two classes

Class 1 (View)

2 1 Back pointers required

3 2 Unordered

4 5 Five items per entry

(Entry template)

5 1 Pointer to view directory

entry

6 2 Line font value

7 1 Pointer to line font directory

entry

8 3 Color number (value) or pointer

272
402, Form 4 VIEWS VISIBLE,

COLOR, LINE WEIGHT

9 2

Class 2 (entity)

Line weight (value)

10 2 Back pointers not required

11 2 Unordered

12 1 One item per entry

13 1 Item is a pointer (to entity)

DESCRIPTION

Directory Data

ENTITY TYPE NUMBER: 402

FORM NUMBER: 4

Parameter Data

Index Name Type Description

1 N

1

Integer Number of blocks containing

the view visible, line font,

color number, and line weight

information

2 N2 Integer Number of entities which

have this particular set of

display characteristics

3 DEVI Pointer Pointer to view entity 1

4 LF1 Integer Line font value or 0

5 DEF1 Pointer If parameter 4 = 0, pointer to a line font definition. Otherwise = 0.

6 CN1 Integer or Pointer

Color number value 1

7 LW1 Integer Line weight value 1

8 DEV2 Pointer Pointer to view entity 2
402, Form 4 VIEWS VISIBLE,

COLOR, LINE WEIGHT

5*Nl+2

5*Nl + 3

5*Nl+N2+2

LWN1 Integer Line weight value N1

DEI Pointer Pointer to entity 1

DEN2 Pointer Pointer to entity N2

Additional pointers as required (see 2.2AA.2).

274
402, Form 5 - ENTITY LABEL DISPLAY

4.3.3. 3.5 FORM NUMBER: 5 Entity Label Display

Some entities may have one or more possible displays for their entity labels,

depending on the view in which they are being displayed. For those entities,

there will be an occurrence of the associativity instance Form Number 5.

In the parameter data portion of the associativity instance, the parameter N

will indicate the number of blocks containing label placement information.

Each block will contain a pointer to a view entity which specifies the view of

visibility. The remaining information (text location, leader, and level

number) applies to the label for that view.

DEFINITION

Index

1

2

3

4

5

6

7

8

9

10

11

Set Value

1

2

1

7

1

2

2

2

1

2

1

Meaning

One class

Back pointers not required

Ordered

Seven items per entry

Pointer to view directory

entry

XT of text location

YT of text location

ZT of text location

Pointer to leader directory

entry

Entity label level number

Pointer to entity

275
402, Form 5 - ENTITY LABEL DISPLAY

DESCRIPTION

Directory Data

ENTITY TYPE NUMBER: 402

FORM NUMBER: 5

Parameter Data

Index Name TyPe Description

1 N Integer Number of label placements

2 DEVI Pointer Pointer to a first view entity

3 XT 1 Real XT coordinate of text location in first view

4 YT1 Real YT coordinate of text location in first view

5 ZT1 Real ZT coordinate of text location in first view

6 DELI Pointer Pointer to leader in first view

7 LLN

1

Integer Entity label level number in first view

8 DEI Pointer Pointer to first entity being

displayed

9 DEV2 Pointer Pointer to second view entity

13 DE2 Pointer Pointer to second entity

being displayed

N-5 DEVN Pointer Pointer to Nlth view entity

• XTN Real XT coordinate of text location in Nth view

YTN Real YT coordinate of text location in Nth view

276
402, Form 5 - ENTITY LABEL DISPLAY

Index Name TyPe Description

• ZTN Real ZT coordinate of text

location in Nth view

• DELN Pointer Pointer to leader in Nth view

• LLNN Integer Entity label level

number in Nth view

7*N+1 DEN Pointer Pointer to Nth entity being

displayed

Additional pointers as required (see 2. 2.4. 4.2)

277
402, Form 7 - GROUP WITHOUT

BACK POINTERS

4. 3. 3. 3. 6 FORM NUMBER:

DEFINITION

Index

1

2

3

4

5

7 Group Without Back Pointers

Set Value Meaning

1

2

2

1

1

One class

Back pointers not required

Unordered

One item per entry

The item is a pointer

DESCRIPTION

Directory Data

ENTITY TYPE NUMBER: 402

FORM NUMBER: 7

Parameter Data

Index Name Type

1 N Integer

2 DEI Pointer

Description

Number of entries

Pointer to entity 1

N+l DEN Pointer Pointer to entity N

Additional Pointers as required (see 2. 2. 4. 4. 2).

278
402, Form 9 - SINGLE PARENT

ASSOCIATIVITY

4.3.3.3.7 FORM NUMBER: 9 Single Parent Associativity

This associativity defines a logical structure of one independent (parent)

entity and one or more subordinate (children) entities.

Both parent and child entities require back pointers to this instance. Any

necessary display parameters are governed by the parent entity.

DEFINITION

Index Set Value Meaning

1

2

3

4

5

6

7

8

9

2

Class 1 (parent)

1

2

1

1

Class 2 (children)

1

1

1

1

Two classes

Back pointers required

Unordered

One item per entry

Item is pointer

to parent entity

Back pointers required

Ordered

One item per entry

Item is pointer

to child entity

279
402, Form 9 - SINGLE PARENT

ASSOCIATIVITY

DESCRIPTION

Directory Data

ENTITY TYPE NUMBER: 402

FORM NUMBER: 9

Parameter Data

Index Name TyPe Description

1 NP Integer Number of Parent

Entities (NP=1)

2 NC Integer Number of Children

3 DE Pointer Pointer to Parent

Entity

4 DEI Pointer Pointer to Child

•

Entity 1

•

• 2+NC DENC

•

Pointer Pointer to Child

Entity NC

Additional Pointers as required (see 2. 2. 4. 4. 2).

280
402, Form 12 - EXTERNAL REFERENCE

FILE INDEX

4. 3. 3. 3. 8 FORM NUMBER: 12 External Reference File Index

The External Reference File Index appears in one file which contains

definitions referenced by another file. It contains a list of the symbolic names used by the referencing files and the DE pointers to the corresponding

definitions within the referenced file. See section 2.5.4 and the External

Reference Entity (Type 416) for more detail.

DEFINITION

Index

1

2

3

Set Value Meaning

1 One class (externally referenced

entities)

2 Backpointers not required

2 Unordered list of entries in a class

4 2 Number of items in an entry

5

6

2 First item is a value (External Reference

Entity Symbolic Name)

1 Second item is a pointer (Internal Entity

DE Pointer)

DESCRIPTION

Directory Data

ENTITY TYPE NUMBER: 402

FORM NUMBER: 12

Parameter Data

Index Name T,ype Description

1 N Integer Number of Index Entries

2 NAME1 String External Reference Entity

Symbolic Name

3 PTR1 Pointer Internal Entity DE Pointer

2N NAMEN String Last External Reference

Entity Symbolic Name

2N+1 PTRN Pointer Last Internal Entity DE

Pointer

Additional Pointers as required (see 2. 2. 4. 4. 2)

281
402, Form 13 - DIMENSIONED GEOMETRY

ASSOCIATIVITY

4.3.3.3.9 FORM NUMBER: 13 Dimensioned Geometry Associativity

This associativity links a dimension entity with the geometry entities it

is dimensioning. The pointers to the entities being dimensioned have

interpretations related to the type of dimension entity. See Figure

4-27.

DEFINITION

Index Set Value Meaning

1 2 Two classes

Class 1 (Dimension Entity)

2 1 Back pointers required

3 2 Unordered

4 1 One item (pointer to dimension)

5 1 Item is pointer

Class 2 (Related Geometry)

6 2 Back pointers not required

7 2 Unordered

8 1 One item per entry (pointers to geometry)

9 1 Item is pointer

282
402 Form 13 - DIMENSIONED GEOMETRY

’ associativity

283
402, Form 13 - DIMENSIONED C-EOMETRY

ASSOCIATIVITY

DESCRIPTION

Directory Data

ENTITY TYPE NUMBER: 402

FORM NUMBER: 13

Parameter Data

Index Name IIP? Description

1 ND Integer Number of dimensions (ND=1)

2 NG Integer Number of associated

geometry entities

3 DIMPTR Pointer Pointer to dimension

4 GEOM1 Pointer Pointer to geometry

entity 1

3+NG GEOMNG Pointer Pointer to geometry

entity NG

Additional Pointers as required (see 2. 2. 4. 4. 2)

284
402, Form 14 - ORDERED GROUP

WITH BACK POINTER

4.3.3.3.10 FORM NUMBER: 14 Ordered Group with Backpointers

DEFINITION

Index Set Value Meaning

1 1 One class

2 1 Back pointers required

3 1 Ordered

4 1 One item per entry

5 1 The item is a pointer

DESCRIPTION

Directory Data

ENTITY NUMBER: 402

FORM NUMBER: 14

Parameter Data

Index Name Type Description

1 N Integer Number of entries

2 DE Pointer Pointer to entity 1

3 DE

• •

Pointer Pointer to entity 2

• •

N+l DE Pointer Pointer to entity N

Additional Pointers as required (see 2. 2. 4. 4. 2).

285
402, Form 15 - ORDERED GROUP

WITHOUT BACK POINTER

4.3.3.3.11 FORM NUMBER: 15 Ordered Group without Backpointers

DEFINITION

Index Set Value Meaning

1 1 One class

2 2 Back pointers not required

3 1 Ordered

4 1 One item per entry

5 1 The item is a pointer

DESCRIPTION

Directory Data

ENTITY NUMBER: 402

FORM NUMBER: 15

Parameter Data

Index Name JX£e Description

1 N Integer Number of entries

2 DE Pointer Pointer to entity 1

3 DE Pointer Pointer to entity 2

N+l DE Pointer Pointer to entity N

Additional Pointers as required (see 2. 2. 4. 4. 2).

286
402, Form 16 - PLANAR ASSOCIATIVITY

4.3.3.3.12 FORM NUMBER: 16 Planar Associativity

This associativity is used to indicate that a collection of entities is coplanar. They may be geometric, annotative, and/or structural. In the case of an entity containing subordinate entities, these must also

be coplanar.

The first class contains the pointer to the transformation matrix

indicating the plane the entities have been moved to. The plane in question is the image under this transformation of the XY plane. As

noted in the description for DE field 7, the value 0 may be used to indicate the identity transformation matrix. This matrix is informational only for the associativity; the constituent entities must

properly position themselves in model space.

The second class contains the pointers to the coplanar entities.

287
402, Form 16 - PLANAR ASSOCIATIVITY

DEFINITION

Index

1

2

3

4

5

6

7

8

9

Set Value

2

Class 1 (Transformation Matrix)

2

1

1

1

Class 2 (Coplanar Entities)

1

2

1

1

Meaning

Two classes

No back pointers

Ordered class

Number of items per entry

Pointer to directory entry

Back pointers required

Unordered class

Number of items per entry

Pointer to directory entry

Directory Data

ENTITY TYPE NUMBER: 402

FORM NUMBER: 16

Parameter Data

Index Name Jype

1 1 Integer

2 N Integer

3 DETR Pointer

4 DEI Pointer

N+3 DEN Pointer

Description

One transformation matrix

Number of entities in this

plane pointed to by this

associativity

Pointer to transformation

matrix moving data from XY

plane into space or zero

Pointer to first entity on plane

specified

Pointer to last entity on plane on

specified

Additional Pointers as required (see 2. 2. 4. 4. 2)

288
402, Form 18 - FLOW ASSOCIATIVITY

4.3.3.3.13 FORM NUMBER: 18 Flow

The Flow Associativity represents a single signal or a single fluid flow

path. The associativity contains seven classes.

Class one contains the type and function flags:

The use of the Type Flag is mandatory when both the logical (e.g.,

schematic) and physical (e.g., printed board) product definitions are in the same file. In such a file, the type flag shall not be zero.

The function flag differentiates between a fluid path and an electrical

conductor:

Function Flag Meaning

0 Not specified (Default)

1 Electrical signal

2 Fluid flow path

A fluid flow path is a single path from a starting connect point entity. The

path may include additional intermediate connect points but separate flow

entities will be required to describe the branch flow paths. Class four, the

Join, lists the elements of the path. For fluid flow paths the elements are ordered as they occur along the flow path and the Connect Points (class

three) lists the connect points in the same sense as the order of the Join.

That is, the start of the fluid flow path is the one listed first; the end of

the fluid flow path is listed last.

Class two contains pointers to other associated flow associativities. These

other associativities may implement alternative flow representations. The

obvious example of this is the file containing both the schematic and

physical product definitions. The corresponding Flow associativities of

each type would be paired.

TyPe FlaS Meaning

0

12

Not specified (Default)

Logical

Physical

289
402, Form 18 - FLOW ASSOCIATIVITY

Class three is the Link, which contains the list of pointers to the Connect

Point entities involved in the signal/flow.

Class four is the Join, which contains the list of pointers to the entities

representing the graphical implementation of the signal/flow.

Class five contains the flow names which are associated with the

signal/flow.

Class six contains a list of pointers to the Text Display Template entities

which are to be used to display the first flow name listed in class five. The

Text Display Templates provide the locations and attributes for the signal

name display.

The text string for display is obtained from the first flow name listed in

class five.

Class seven contains a list of pointers to flow paths which branch from the

current flow path. This is an ordered list and the "main" continuation of

the path, if any, is always listed last. A null pointer is used if there is no

continuation of the main path.

2QO
402, Form 18 FLOW ASSOCIATIVITY

DEFINITION

Index Set Value Meaning

1

2

3

4

5

6

7

8

9

10

1112

13

1415

16

17

18

19

20

21

22

23

24

25

26

27

28

29

7

Class 1 (Context Flag)

2

1

12

Class 2 (Associated Flows)

2

2

1

1

Class 3 (Connect Points (Link))

1

11

1

Class 4 (Join)

1

1

1

1

Class 5 (Flow Name)

2

2

12

Class 6 (Flow Name Display)

22

1

1

Class 7 (Flow Continuations)

1

1

1

1

Seven classes

Back pointers not required

Ordered

One item per entry

Item is value

Back pointers not required

Unordered

One item per entry

Pointer to Flow Associativity

Back pointers required

Ordered

One item per entry

Pointer to Connect Point Entity

Back pointers required

Ordered

One item per entry

Pointer to geometry or Subfigure

instance

Back pointers not required

Unordered

One item per entry

Item is value

Back pointers not required

Unordered

One item per entry

Pointer to Text Display Template

Entity

Back pointers required

Ordered

One item per entry

Item is a pointer

291
402, Form 18 - FLOW ASSOCIATIVITY

The Status Flag values should be set as follows:

Subordinate To be set by sending system

Entity Use 03

Hierarchy 00

DESCRIPTION

Directory Data

ENTITY TYPE NUMBER: 402

FORM NUMBER: 18

Parameter Data

Index Name Jype Description

1 NCF Integer Count of context flags (=2)

2 NF Integer Count of associated Flow associativities

3 NC Integer Count of Connect Point entities

4 N3 Integer Count of Join entities (geometry of subfigure)

5 NN Integer Count of Flow names

6 NT Integer Count of Text Display Templates for Flow

name display

7 NP Integer Count of continuation flow associativities

8 TF Integer Type of Flow

0 = not specified (Default)

1 = logical

2 = physical

. other as required

9 FF Integer Function flag:

0 = not specified (Default)

1 = electrical signal

2 = fluid flow path

. other as required

292
402, Form 18 - FLOW ASSOCIATIVITY

Index

10

NF+9

NF+10

NF+NC+9

NF+NC+IO

NF+NC+N3+9

NF+NC+N3 + 10

NF+NC+N3+NN+9

NF+NC+N3+NN + 10

NF+NC+N3+NN+NT+9

NF+NC+N3+NN+NT+10

NF+NC+N3+NN+NT+NP+9

Name TyPe Description

SPTR1 Pointer Pointer to directory entry for Flow

Associativity 1

SPTRNF Pointer Pointer to directory entry for Flow

Associativity NF

CPTR1 Pointer Pointer to directory entry for Connect

Point 1

CPTRNC Pointer Pointer to directory entry for Connect

Point NC

3PTR1 Pointer Pointer to 3oin entity 1

3PTRN3 Pointer Pointer to 3oin entity N3

NAME1 String Flow name 1

NAMENN String Flow Name NN

GPTR1 Pointer Pointer to directory entry for Text

Template 1

GPTRNT Pointer Pointer to directory entry for

Text Template NT

CFPTR1 Pointer Pointer to continuation flow

associativity entity 1

CFPTRNP Pointer Pointer to continuation flow

associativity entity NP (the "main"

continuation)

Additional Pointers as required (see 2.2AA.2)

293
THIS PAGE INTENTIONALLY LEFT BLANK

294
402 - OBSOLETE ASSOCIATIVITY FORMS

4.3.3.3.14 Obsolete Associativity Forms

The addition of new entities and associativities which greatly increase the

capability for transfer of specific data constructs has given cause to deprecate

associativity forms published in previous versions of this Specification. The

parameter lists for these forms are included herein to provide for interpretation

of files created under an earlier version. The new associativity forms or entities

which are valid for the previous forms are as follows:

OBSOLETE FORM // VALID FORM // OR ENTITY TYPE #

6 View List 3 Views Visible

8 Signal String 18 Flow

10 Text Node 312 Text Template

11 Connect Node 132 Connect Point

The parameter lists for these following associativities may have additional

parameters as specified in section 2. 2. 4. 4. 2:

295
402 - OBSOLETE ASSOCIATIVITY FORMS

4.3.3.3.14.1 FORM NUMBER: 6 View List

DEFINITION

Index

1

2

3

4

5

6

7

8

9

DESCRIPTION

Directory Data

ENTITY TYPE NUMBER:

FORM NUMBER: 6

Parameter Data

Index Name

1 1

2 N

1

3 DEV

4 DEI

Nl+3 DENI

Set Value

2

Class 1 (View)

1

2

1

1

Class 2 (Entities)

1

2

1

1

402

Meaning

Two classes

Back pointers required

Unordered

One item per entry

Pointer to view directory

entry

Back pointers required

Unordered

One item per entry

Pointer to directory entry of

entity visible in view

Type Description

Integer Single entry in first class

Integer Number of entities in second class

Pointer Pointer to view entity

Pointer Pointers to entities visible in view specified in parameter 3

Pointer

296
402 - OBSOLETE ASSOCIATIVITY FORMS

4.3.3.3.14.2 FORM NUMBER: 8 Signal String

DEFINITION

Index Set Value Meaning

1 Class 1

4(Signal Names)

Four classes

2 2 Back pointers not required

3 1 Ordered

4 1 One item per entry

5 Class 2

2(Connections)

Item is value

6 1 Back pointers required

7 2 Unordered

8 1 One item per entry

9

Class 3

1(Schematic)

Pointer to Connect Node

10 1 Back pointers required

11 1 Ordered

12 1 One item per entry

13

Class 4

1(Physical Layout)Pointer to geometry

14 1 Back pointers required

15 1 Ordered

16 1 One item per entry

17 1 Pointer to geometry

DESCRIPTION

Directory Data

ENTITY TYPE NUMBER:

FORM NUMBER: 8

402

Parameter Data

Index Name Type Description

1 NS Integer Number of signal names

2 N

1

Integer Number of Connection Nodes

3 N2 Integer Number of Entities in schematic signal string

4 N3 Integer Number of Entities in physical signal string

5 SIG

1

String Signal name

NS+4 SIGNS

297
402 - OBSOLETE ASSOCIATIVITY FORMS

Index Name Type Description

NS+5 PCI Pointer Pointer to Connect Nodes

NS+N1+4 PCN

1

Pointer

NS+N1+5 PS1 Pointer Pointer to Entity in schematic logical signal

string

NS+N2+N 1+4 PSN2 Pointer

NS+N2+N 1+5 PP1 Pointer Pointer to entity in physical signal string

NS+N3+N2+N

1

+4 PPN3 Pointer

298
402 - OBSOLETE ASSOCIATIVITY FORMS

4.3.3.3.14.3 FORM NUMBER: 10 Text Node

DEFINITION

Index Set Value

1

2

Class 1 (Geometry Pointers)

Meaning

Two classes

2 1

3 1

4 1

5 1

Class 2 (Text Description)

6 2

7 1

8 7

9 2

10 2

11 3

12 2

13 2

14 2

15 2

Back pointers required

Ordered class

One item per entry

Item is pointer (to point entity)

Back pointers not required

Ordered class

Seven items/entry

Box length

Box height

Font characteristic

Slant angle

Rotation angle

Mirror flag

Rotate internal flag

299
402 - OBSOLETE ASSOCIATIVITY FORMS

DESCRIPTION

Directory Data

ENTITY TYPE NUMBER: 402

FORM NUMBER: 10

Parameter Data

Index Name lypg Description

1 NP Integer Number of geometry pointers

2 1 Integer One Text Description

3 GP1 Pointer Pointer to point (original location)

4 GP2 Pointer Pointer to instance point (first instance)

NP+2 GPNP Pointer Pointer to instance point (NP-1 instance)

NP+3 WT Real Box length

NP+4 HT Real Box height

NP+5 FC Integer

or pointer

Font characteristic (default = 1)

NP+6 SL Real Slant angle of text in radians, pi/2 is the

value for no slant angle and is the default

value.

NP+7 A Real Rotation angle in radians for text.

NP+8 M Integer Mirror flag (0=no mirror, 1=YT mirror

axis, 2=XT mirror axis.)

NP+9 VH Integer Rotate internal text flag

(0=text horizontal,

l=text vertical)

300
402 - OBSOLETE ASSOCIATIVITY FORMS

4.3.3.3.14.4 FORM NUMBER: 11 Connect Node

DEFINITION

Index

1

2

3

4

5

Set Value

2

Class 1 (Geometry pointers)

1

1

1

1

6

7

8

9

Class 2 (Connection entities)

2

2

1

2

Meaning

Two classes

Back pointers required

Ordered class

One item per entry

Pointer (to point entity)

Back pointers not required

Unordered class

One item per entry

Item is value

301
402 - OBSOLETE ASSOCIATIVITY FORMS

DESCRIPTION

Directory Data

ENTITY TYPE NUMBER: 402

FORM NUMBER: 11

Parameter Data

Index Name IXpe Description

1 NC Integer Number of pointers (to points)

2 NP Integer Number of entries in second class

3 PT1 Pointer Pointer to defining point (original location)

4 PT2 Pointer Pointer to instance point (first instance)

NC+2 PTNC Pointer Pointer to last instance point (NC-1 instance)

NC+3 DTI Data First data entry

NC+NP+2 DTNP Data Last data entry

302
404 DRAWING

4.3.4 Drawing Entity.

The Drawing entity specifies a drawing as a collection of annotation entities

(i.e., any entity with use flag set to 01) defined in drawing space, and views

(i.e., projections of model space data in view space) which, together, constitute

a single representation of a part, in the sense that an engineering drawing

constitutes a single representation of a part in standard drafting practice.

Views are specified by referring to the View Entity. If desired, multiple

drawings can be included in a single file, referring to the same model space.

Drawings are located in drawing space as illustrated in Figure 4-28, with sides

coincident with the drawing coordinate system axes, and with the lower left corner at the origin (0,0). The drawing space coordinate system (XD, YD) is a

special 2-dimensional coordinate system used for view origin locations in the

Drawing entity and for annotation entities referenced by the Drawing entity.

Any Z coordinates are ignored in the referenced annotation entities and any

transformation matrix from definition space to drawing space must be 2- dimensional (i.e., in entity 124, T3=Rj3=R.3i=R32=R23=0*0 and R33=1.0).

Annotation entities can be defined in drawing space and be referenced by the

Drawing entity directly, or can be defined in model space and appear in individual views. When defined in drawing space, the subordinate entity switch

should be set to physically dependent (01). The subordinate entity switch for a View entity referenced by the Drawing entity should be set to logically

dependent (02).

The transformation of a view from view space to drawing space is controlled by

the view scale factor S, specified in the View entity, and the view origin

drawing locations, specified in the Drawing entity. In the case of orthographic

parallel projection the transformation is:

XD S 0 0

XV

+ XORIGIN

YD 0 s 0

YV YORIGIN

. zv _

303
404 DRAWING

where

XV

YV

ZV

denotes the view space coordinates

XORIGIN

denotes the drawing space coordinates of the

origin of the transformed view (see 4.3.11).

and

YORIGIN

If known, the name of the drawing may be provided by using the Name Property

(406, form 15). If not provided, a receiving system may default the name of the

drawing.

The size of the drawing may be communicated by using the Drawing Size

Property (406, form 16).

The units for drawing space may be different from the model space units

specified in the Global section. This is accomplished by use of the Drawing

Units Property (406, form 17). When this property is not provided, the drawing

units will be the same as the model units.

The following values are given in drawing units:

Refer to Figures 4-28 and 4-29 for examples of the use of the drawing entity.

- view origin drawing locations

- drawing size

- coordinates of annotation entities referenced directly

304
404 DRAWING

FIGURE 4-28 DRAWING ENTITY EXAMPLE 1

305
404 DRAWING

FIGURE 4-29 DRAWING ENTITY EXAMPLE 2

306
404 DRAWING

4.3.4.1 Directory Data

ENTITY TYPE NUMBER : 404

‘.3.4.2 Parameter Data

Parameter Value Format Comment

1 N Integer Number of view pointers

2 VPTR1 Pointer Pointer to directory entry of

first view entity

3 XORIGIN1 Real Drawing space coordinate of

the origin of the first transformed view

4 YORIGIN1 Real Drawing space coordinate of

the origin of the first

transformed view

5 VPTR2 Pointer Pointer to directory entry of

second view entity

3N+2 M Integer Number of annotation

entities (may be zero)

3N+3 DPTR1

•

Pointer Pointer to first annotation

entity in this drawing

3N+M+2

• DPTRM Pointer Pointer to Mth annotation

entity in this drawing

Additional Pointers as required (see 2. 2. 4. 4. 2)

307
304 - LINE FONT DEFINITION

4.3.5 Line Font Definition Entity.

Two types of line fonts may be defined. One type considers a line font as a

repetition of a basic pattern of visible-blanked (or, on-off) segments

superimposed on a line or a curve. The line or curve is then displayed

according to the basic pattern. The other type considers a line font as a repetition of a template figure that is displayed at regularly spaced locations

along a planar anchoring curve. The anchoring curve itself has no visual

purpose.

Any line or curve geometry entity type may reference a Line Font Definition

entity by inserting a pointer to that entity in its Directory Entry field 4, the

line font pattern field. The type of line font being specified is then indicated

by a Form Number in the Line Font Definition entity.

Setting the Form Number to 1 in a Line Font Definition entity specifies that

the line font type is to be a repetition of template figure displays along the

referencing anchoring curve. The template figure is specified as a subfigure

definition entity. In this case, four Index values specify the entity as follows:

The first parameter specifies the orientation of the template displays. This

may remain constant, or it may vary with the direction of the anchoring curve at the point of each template figure display location. The second

parameter is a pointer to the subfigure definition entity containing the

template display. The third parameter specifies display locations on the

anchoring curve by giving the common arc length distance between

corresponding points on successive template figure displays. The fourth

parameter gives a scale factor to be applied to the template subfigure at each display location.

Figure 4-30 illustrates two examples of a line font with Form Number equal

1. In each case, the anchoring curve is a straight line.

308
304 - LINE FONT DEFINITION

309

FIGURE

4-30

USE

OF

SUBFIGURE

WITH

LINE

FONTS
304 - LINE FONT DEFINITION

Setting the Form Number to 2 in a Line Font Definition entity specifies that

the line font type is to be a repetition of a basic visible-blank pattern

superimposed on the referencing line or curve. An arbitrary number M of

segments may be used in the basic pattern. When the basic pattern is laid out

horizontally, the "first" segment is the leftmost one, the "Mth" segment is the rightmost one. The length (in the units of the curve on which the pattern

is being superimposed) of each segment of the pattern may be specified

individually. This allows the visible-blank sequence of the pattern to alternate between "visible" and "blank" regardless of the lengths of the

segments, but does not prohibit adjacent segments from being either both

visible or both blanked when unequal lengths are employed. Another option

for some patterns is to hold the length constant across segments, and achieve

variation in the lengths of the visible and blanked segments by making the

"visible" and/or the "blank" segments be adjacent as required.

For example, a basic pattern whose left two-thirds is visible, and whose right

third is blanked may be described either by the sequence "visible-blank*' with

the length of the first segment twice that of the second, or else by the

sequence "visible- visible-blank", with the lengths of all three segments equal.

The visible-blank sequence is specified by correlating it with the rightmost M

bits in the binary representation of a string of hexadecimal digits, the Mth

segment being associated with the units bit of the binary representation of

the rightmost hexadecimal digit. A "0" represents a "blank", or "off"

segment, a "1" represents a "visible", or "on" segment.

For this line font type, the first parameter is the positive integer M giving

the number of segments in the basic pattern. Then, parameter values 2 through M+2 specify the entity as follows:

Parameter values 2 through M+l give the lengths of the M segments.

Parameter value M+2 is the minimal string of hexadecimal digits whose

significance has been described above.

310
304 - LINE FONT DEFINITION

Figure 4-31 shows an example of the Form Number 2. Shown is a font made

up of five segments of unequal length. Two repetitions of the basic font are

illustrated.

Form Meaning

1 Line font specified by a repeating template subfigure

2 Line font specified by a repeating visible-blanked pattern

3.5.1 Directory Data

ENTITY TYPE NUMBER: 304

FORM NUMBER: 1

3.5.2 Parameter Data

Index Name Type Description

1 M Integer M=0:Each template display is oriented by aligning the axes

of the subfigure definition

coordinate system with the axes of the definition space

of the anchoring curve.

M=l: Each template display

is oriented by aligning the X

axis of the subfigure

definition coordinate system

with the tangent vector of

the anchoring curve at the

point of incidence of the curve and the origin of the

subfigure, and the Z axis of

the subfigure definition

coordinate system with the Z

axis of the definition space

of the anchoring curve.

2 LI Pointer Pointer to the subfigure

definition for the template

displays.

3 L2 Real Common arc length distance

between correspond "ng points on successive template figure

displays.

4 L3 Real

Additional Pointers as Required (see 2. 2. 4.4. 2)

Scale factor to be applied to the subfigure.
304 - LINE FONT DEFINITION

4. 3. 5. 3 Directory Data

ENTITY TYPE NUMBER: 304

FORM NUMBER: 2

4. 3. 5. 4 Parameter Data

Index Name Iyp.e Description

1 M Integer Number of segments in the

basic pattern of visibleblanked segments.

2 LI Real Length of the first segment

of the basic pattern.

3 L2 Real Length of the second

segment of the basic pattern.

4 L3 Real Length of the third segment

•

of the basic pattern.

M+l LM Real Length of the Mth segment

of the basic pattern.

M+2 6 String /M - l\ , v

+1

hexadecimal digits indicating

which segments of the basic

pattern are visible and which

are blanked, where

represents the greatest

integer result. E.g., "5"

indicates that segments 1 and

3 are visible. Bits are right

justified.

Additional Pointers as Required (see 2. 2. 4. 4. 2)

312
304 - LINE FONT DEFINITION

313

FIGURE

4-31

CONSTRUCTION

OF

LINE

FONTS
306 - MACRO

4.3.6 MACRO Capability

4.3.6. 1 General. This Specification provides a means for communicating 3-dimensional and 2-dimensional geometric models and drawings. The Spedfication,

however, does not provide a format for every geometric or drafting entity

available on all currently used CAD/CAM systems, and is thus a common

subset of such entities. To allow exchange of a larger subset of entities - a

subset containing some of the entities not defined in this Spedfication but

which can be defined in terms of the basic entities, the MACRO capability is provided. This capability allows the use of the Spedfication to be extended

beyond the common entity subset, utilizing a formal mechanism which is a

part of the Specification.

The MACRO capability provides for the definition of a "new" entity in terms

of other entities. The "new" entity schema is provided in a MACRO

definition which occurs once for every "new" entity in the file. Instances of

these "new" entities are replaced during the MACRO processing by the

constituent entities specified in the corresponding MACRO definition.

A MACRO definition is written using the MACRO definition entity. The

parameter section of the entity contains the MACRO body. In the MACRO

body, eleven types of language statements are usable. The statements are LET, SET, REPEAT, CONTINUE, BREAK, IF, LABEL, GOTO, MACRO,

ENDM, MREF. The details of the MACRO syntax are given in 4. 3. 6. 2. Each

of the statements in a MACRO definition entity is terminated by a record

delimiter.

In order to use a "new" entity defined by the MACRO definition, a MACRO

instance is placed in the file. The directory entry portion of an instance

specifies the new entity type number in field 1 and 11 of the directory entry

record and refers to the definition by a pointer in the structure field (DE

field 3). The parameters for the instance are placed in the parameter record

of the instance.

314
306 - MACRO

The directory entry record of a MACRO definition has a standard form.

The attributes 4 through 9, 12, 13, 15, 18, and 19 have no significance. The

default values for these attributes are taken from the directory entry record

of the MACRO instance (described in 4. 3.6. 4).

The parameter data records of a MACRO definition consist of MACRO

language statements. The statements are not in Hollerith form, i.e., they

have no preceding "H" specification. The statements are free format and

may branch over record boundaries (see 2.2.3). Every statement is terminated by a record delimiter.

4. 3.6. 2 MACRO Syntax

Constants. Constants may be integer, real, double precision real, pointer or

string (See 2.2.2).

Variables. Variable names may be from one to six characters in length. The

first character must be one of the characters listed below. This character

determines the variable type. It is not possible to override the conventions.

The six character limitation includes the first character. Upper and lower

case letters are recognized as distinct, i.e., X is different from x. Variable names longer than six characters may be used; however, only the first six

characters will be significant. Variable names may contain imbedded blanks.

These blanks are NOT taken as part of the name; therefore "A B" is equivalent to "AB." Except for the first character, as outlined below, all characters must be alphabetic (A-Z or a-z), or numeric (0-9).

315
306 - MACRO

Variable type

Integer

Real

Double precision real

String

Pointer

Label

First character

I-N, i-n A-H, O-Z a-h, o-z

i

$

it&

Examples of valid variable names are: Integer: IJK ICOUNT K101 NTIMES

Real: XYZ XI y2 QrsTul

Double precision real:

!h !xi !Y2 112341

String: $str $TITLE $label

Pointer: //line it note //REF //XYZ1

max

Some invalid variable names:

$$$$ ($ not permitted after first character)

1X43B (1 may not be first character)

A.BC (. is illegal)

Note that there are no "reserved" words. Thus a variable name such as "MACRO", which is identical to a statement keyword (described below),

will not confuse the interpreter, although it may confuse the user of such a MACRO. It is suggested that these words be avoided.

Functions. Functions similar to FORTRAN library functions are provided.

The rules for mixed mode have been relaxed so that it is not necessary to use SQRT(2. ) instead of SQRT(2). While this assists the preprocessor writer in preparing MACROS, it places a responsibility on the writer of a processor for the MACRO language in handling the mixed mode. While the arguments can

be mixed mode, the functions do have a specific type of value that they

return, i.e., integer, real, double precision real, or string. The functions are

listed here by the type of value returned. The type of argument usually used

is also noted for clarity. For example, either IDINT(ld) or INT(!d) will work

316
306 - MACRO

equally well, although the meaning might be a little clearer with IDINT(!d).

Functions are only recognized in upper case.

FUNCTIONS RETURNING INTEGER VALUES:

IABS(i)

Returns the absolute value of i. IDINTOd)

Returns integer part of !d. IFIX(x) or INT(x)

Returns the integer part of x.

ISIGN(i)

Returns 1 if i is positive, 0 if it is zero, or -1 if it is negative.

FUNCTIONS RETURNING REAL VALUES:

ABS(x)

Returns absolute value of x. AINT(x)

Returns integer part of x, in real form.

ALOG(x)

Returns natural logarithm of x. ALOGlO(x)

Returns common (base 10) logarithm of x. ATAN(x)

Returns arctangent of x; angle returned in radians.

COS(x)

Returns cosine of angle x; angle in radians.

EXP(x)

Returns natural anti-logarithm of x ("e to the x").

FLOAT(i)

Returns a real (floated) value for i, e.g., FLOAT(2) returns "2." SIGN(x)

Returns 1. if x is positive, 0. if x is zero, and -1. if x is negative.

317
306 - MACRO

SIN(x)

Returns sine of angle x; angle in radians.

SNGL(ld)

Returns single precision (real) value of double precision variable !d. As

many significant digits of !d as possible are used in the returned value.

SQRT(x)

Returns square root of x. TAN(x)

Returns tangent of angle x; angle in radians.

FUNCTIONS RETURNING DOUBLE PRECISION REAL VALUES:

DABS(Id)

Returns absolute value of !d. DATAN('.d)

Returns arctangent of ! d; value returned in radians.

DBLE(x)

Returns double precision real value of x. Note that this is merely a conversion, not an extension. Thus, DBL(. 333333333) will return .333333333D0, but not .333333333333333333333333D0. Thus,

DBLE(l./3.) is not necessarily equal to 1D0/3D0.

DCOSOd)

Returns cosine of angle !d; angle in radians.

DEXPOd)

Returns natural anti-logarithm of !d(i.e., e to the !d). DLOG(!d)

Returns natural logarithm of !d. DLOGlO(Id)

Returns common (base 10) logarithm of !d. DSIGN(!d)

Returns 1D0 if !d is positive, 0D0 if zero, -1D0 if negative.

DSINOd)

Returns sine of angle !d; angle in radians.

DSQRTOd)

Returns square root of !d.

318
306 - MACRO

DTAN(!d)

Returns tangent of angle !d; angle in radians.

FUNCTIONS RETURNING STRING VALUES:

STRING (expression, format)

Returns the character representation of the argument "expression". See

section 4. 3.6. 3. 3 for a description of the argument "format".

Expressions. Expressions may be formed using the above functions, variables

and constants, and the following operators:

Function Symbol

addition + Subtraction

multiplication *

division / exponentiation **

The operators are evaluated in normal algebraic order, i.e., first exponentiation, then unary negation, then multiplication or division, then

addition or subtraction. Within any one hierarchy, operators evaluate left to

right. Parentheses may be used to override the normal evaluation order, as in the expression "A*(B+C)," which is different from "A*B+C." Extra

parentheses do not alter the value of the expression; it is a good idea to use them, even if not truly necessary. Examples of expressions include:

X+1.0

-B+SQRT(B**2 - 4*A*C)

I + 1 3.14159/2.

-X

!DEL*(!ALPH A-1BETA)

319
306 - MACRO

Except for the ** operator, it is never permissable to have two operators

next to each other, i.e., not 2*-2, but -2*2 or 2*(-2). Multiplication may not

be implied by parentheses, e.g., (A+B)(C+D) is invalid, and AB does not imply

A*B, but rather the separate variable AB.

Mode of expression evaluation . Mixed mode (integer mixed with real, etc.) is permitted. Whenever two different types are to be operated upon, the

calculation is performed in the "higher" type. Integer is the lowest type, real

is next, and double precision real is the highest. Note, however, that this

decision is made for each operation, not once for the entire expression. Thus

1/3 + 1.0 evaluates to 1.0, because the "1/3" is done first, and it is done in integer mode. Integer mode truncates fractions, and does not round.

Therefore, the expression "2/3+2/3+2/3" has a value of zero.

Conditional expressions

Conditional expressions may be formed using functions, variables and

constants and the following six standard relational operators:

Function Symbol

less than or equal <£> .LE.

less than (O .LT. equal («) .EQ.

greater than or equal (fc> .GE.

greater than (>) .GT.

not equal (/) .NE.

Examples of conditional expressions include:

X.GT.3

SQRT(A+B).NE.I+1

(!A-!B).GE.3.14159

320
306 - MACRO

4.3. 6. 3 MACRO Definition Entity. The MACRO definition entity specifies the action

of a specific MACRO. After having been specified in a definition entity, the

MACRO can be used as often as necessary by means of the MACRO instance

entity.

The MACRO definition entity differs from other entity structures in this

Specification by consisting of only language statements in the parameter

data. The character strings constituting the language statements in the

MACRO definition are not set off by means of the nH structure of string

constants but rather consist of only the actual character string terminated by

a record delimiter (see 2. 2. 2. 5).

4. 3. 6. 3.1 Directory Data

ENTITY TYPE NUMBER: 306

4. 3. 6. 3. 2 Parameter Data

Index Name TyPe Description

1 ID Literal MACRO

2 NE Integer Entity Type ID

3 TEXT Language statement First statement

4 TEXT Language statement Second Statement

N+2 TEXT Language statement Last statement

N+3 T Literal ENDM

Additional parameters as required (see 2. 2. 4. 4. 2).

321
306 - MACRO

4.3. 6. 3.3 There are eleven language statements that can be used. They are: LET

SET

REPEAT

CONTINUE

BREAK

IFLABEL

GOTO

MACRO

ENDM

MREF

These "keywords" are recognized only in upper case, and every statement

must begin with one of these keywords. Statements are free format; blanks

and tabs are ignored except within strings. Statements may extend over

several lines, or more than one statement may be present on a line. All statements are terminated by a record delimiter which must be present.

LET statement (Arithmetic)

This is the assignment statement and is equivalent to the LET statement of

BASIC. The format of a LET statement is:

LET variable = expression;

The expression and the variable may be integer, real, or double precision;

they need not be of the same type. Note that this is an assignment statement

and not an algebraic equality. All of the variables on the right hand side of

the expression must have been previously defined; it cannot be assumed that

variables will default to zero if they are undefined. Some examples of valid

LET statements:

LET HYPOT = SQRT(A**2+B**2);

LET X = X + 1; LET ROOT1 = -B + SQRT(B*B - 4*A*C);

LET I = i; LET !XYZ = 1*2;

LET START = 0;

322
306 - MACRO

LET Statement (String)

String variables allow characters to be manipulated. String variables may be

used in statements almost anywhere that any other variable type may be

used; exceptions are noted below.

String variables may be used in LET statements. Note that they shall not be

mixed with any other type of variable in a LET statement. Also note that

arithmetic operations (i.e., *, /,**) are not possible with string variables.

Two forms of LET statements for string variables are possible:

LET $str = 23Hstring of 23 characters;

orLET $strl = $str2;

In the first case, the 23 characters following the H are assigned to the string

variable $str. In the second case, the string "$str2" is copied into "$strl."

Examples of these statements include:

LET $title = 3HBox;

LET $subti = 6HBottom;

LET $x = $subti;

Note that if a string variable appears on the right hand side of the statement,

it must have been previously defined. Spaces are not ignored within a string constant; they become part of the string. Any printable ASCII character may

be part of a string.

There is one other form for setting up a string. It involves the STRING

function. The STRING function may only appear in this form. Specifically, it

shall not appear in SET statement argument lists, MACRO statements, or MREF statements. However, string constants, such as "6Hstring," and

variables, such as "$x" , may appear in SET statements and MACRO

statements.

323
306 - MACRO

The form of a LET statement including string function is:

LET $str = STRING(expression, format);

where "expression" is any normal integer, real or double precision real

expression, "$str" is a string variable name, and "format" is a format

specification as used in a FORTRAN FORMAT statement. The allowable

format specifications are:

Iw

Fw.d

Ew.d

Dw.d

The effect of this statement is to convert the numeric value of the

expression into characters, e.g., the statement:

LET $P1 = STRING(3.14 159,F7.5);

will result in the same thing as LET $PI = 7H3.14159;

Of course, the usefulness of the STRING function is that expressions can be

converted, rather than constants. Thus:

LET x = lj LET y

= 2; LET $xyz = STRING(x+y+l,F5.0);

will result in the same thing as LET $xyz = 5H 4.;

The rules for the format specifications follow the standard FORTRAN

convention. "Iw" causes integer conversion, resulting in "w" characters.

"Fw.d" causes real conversion, resulting in "w" characters, with "<f' characters after the decimal point. "Ew.d" results in real conversion, but

using an exponent form. "Dw.d" is the same as "E" but for double precision

real values. Note that this is one place where mixed mode is not allowed.

The type of format specification and the type of the expression's result must

be identical.

324
306 - MACRO

LET statements (Attributes)

Attributes (those appearing in the directory entry record for the MACRO

instance) may be set using the LET statement. The format is:

LET /attribute name = expression;

orLET /attribute name = /HDR;

The first form allows an attribute to be set to any constant value, including

numeric expressions. Attributes may also be set to string constants or string

variables, but not to the result of a STRING function.

Examples:

LET /LEV = 1; LET /VIEW = 3; LET /LABEL = 6HBottom;

LET /LABEL = $X;

The second form allows restoring an attribute to its default value.

Examples:

LET /LEV = /HDR;

LET /LABEL = /HDR;

The word "/HDR" is the only non-constant that is allowed on the right side of an attribute assignment statement. The effect is to restore the value of the

attribute to what it was in the directory entry for the instance or, in some

cases, to a specified default value. The defaults are described below.

Attributes may not be mixed with any other variable type nor may they

appear anywhere but in the above two forms of LET statements.

325
306 MACRO

The allowable attribute names and their defaults are given here. A default of

/HDR indicates that the attribute defaults to the value in the directory entry

of the instance.

Attribute Name Default

Line font pattern /LFP /HDR

Level /LEV /HDR

View /VIEW /HDR

Transformation matrix /MTX /HDR

Label display associativity /CE 0

Blank status /BS /HDR

Subordinate entity /SE /HDR

Entity use /ET /HDR

Hierarchy /HF /HDR

Line weight /LW /HDR

Color /PN /HDR

Form /FORM 0

Entity label /LABEL blanks

Entity subscript /SUB 0

SET statement

The SET statement establishes directory and parameter data entries for the

specified entity. The form is:

SET //ptr = entity type number, argument list;

"//ptr" is a pointer variable, such as '7/XYZ"; "entity type number" is an 1GES

entity type number, such as "110"; and "argument list" is a group of variables

which is the parameter data of the entity.

Examples of this type of SET statement:

SET //LINE = 1 10,X 1,Y 1,Z,X2,Y2,Z,0,0;

SET //ABC = 828,Z,A+B/C,Y1,X2,Y2+1,0,0;

SET //qwe = 864,15Hstrings allowed, X,Y,$this2;

326
306 - MACRO

The argument list may contain expressions and may spread over more than one line. At least one argument must be present, i.e., the argument list may

not be null. The entity type number may not be an expression; i.e., it must be

an integer constant. The pointer variable will be assigned a value

corresponding to the sequence number of the directory entry of the entity

created.

"Forward referencing" of pointers is valid in the argument list of a SET

statement. A pointer may appear in the argument list of a SET statement

that comes before the SET statement defining the pointer. The only

restriction is that any pointer so referenced must appear on the left hand side

of one SET statement.

Pointers which appear on the left hand side of more than one SET statement

or those which are located inside of REPEAT loops should not be forward

referenced.

Note that the STRING function is not allowable in a SET statement — use a

separate LET statement with a string variable instead.

REPEAT statement

The REPEAT statement causes a group of statements terminated by a CONTINUE statement to be repeated a specified number of times. The form

of a REPEAT statement is:

REPEAT expression;

327
306 - MACRO

The expression is evaluated, and the resulting value is the number of times

the statements will be repeated. The expression may be of integer, real or double precision real type; in the case of real or double precision real

expressions, the result is truncated to determine the repeat count. If the

repeat count is zero or negative, the group of statements is still executed one

time.

Examples of REPEAT statements:

REPEAT 3; REPEAT N+l;

REPEAT 0; (will execute the loop one time)

REPEAT X+Y;

REPEAT statements may be nested only to a depth of ten.

After a REPEAT statement, such as REPEAT N, it is valid to alter the value

of N. This does not affect the repeat count. Also note that REPEAT is

unlike a FORTRAN DO statement because there is no variable being

incremented on every pass.

CONTINUE statement

The CONTINUE statement marks the end of a REPEAT group. The form of a CONTINUE statement is:

CONTINUE;

When a CONTINUE statement is encountered, the repeat count is decremented by one and checked to see if it is greater than zero. If it is, the

interpreter goes back to the first statement after the most recent REPEAT.

If not, then the next statement is processed. The number of REPEAT

statements and CONTINUE statements in a MACRO shall be the same. A

CONTINUE statement(s) is not implied by ENDM.

328
306 - MACRO

BREAK statement

A BREAK statement may be used within a REPEAT construct to terminate

the processing of statements of the REPEAT construct before the completion

of the specified number of loops, such as upon detection of a condition during

the processing. The form of a BREAK statement is:

BREAK;

or

IF conditional expression, BREAK;

When a BREAK statement is encountered, processing of MACRO statements resumes with the statement immediately following the CONTINUE statement

marking the end of the affected REPEAT construct.

IF statement

The IF statement causes a single language statement to be executed if a

certain condition is true.

The form of an IF statement is:

IF conditional expression, language statement;

where "conditional expression" is a conditional expression as described in section 4. 3. 6. 2. "language statement" can be any statement allowed in a MACRO except:

MACRO

ENDM

IFLABEL

Examples of IF statements:

IF A.LT.3,LET A=3;

IF B.EQ.0,SET //LIN 1 = 1 10,...; IF SWITCH.EQ.l, GOTO &A;

329
306 - MACRO

LABEL statement

The LABEL statement is used to mark a position in a MACRO where the

execution control is transferred to using a GOTO statement.

The form of a LABEL statement is:

LABEL label name;

where "label name" is any character string beginning with an ampersand (<5c).

It should be from one to six characters long (including the <5c). Within a single

MACRO definition, all label names must be unique.

Examples:

LABEL <5doop;

LABEL &end;

GOTO statement

This statement is used to transfer the execution control to a particular point

which is marked by a LABEL statement.

The form of a GOTO statement is:

GOTO label name;

where 'label name' is any label name specified in a LABEL statement.

The GOTO statement can be used to jump both forward and backward, but

both the GOTO statement and the target LABEL must be at the same nesting

level and within the same REPEAT construct.

Examples:

GOTO &start; GOTO &end;

330
306 - MACRO

MACRO statement

The MACRO statement is used to signify the start of a MACRO definition.

The first statement in every MACRO definition must be a MACRO

statement.

The form of a MACRO statement is:

306,MACRO, entity type number, argument list;

where "entity type number" is the assigned entity number of the MACRO, and

"argument list" is a list of parameters that are to be assigned values at execution time. Entity type numbers in the range of 600 to 699 and 10000 to 99999 will be used.

The argument list may not be null. The parameters in the argument list take

the form of the variables described in Section 4. 3. 6. 2. Note that the

argument list may not contain expressions, only symbolic variable names.

One additional type of variable, the "class variable" can be used in an argument list. The class variable takes the form:

size_variable (class_var_l, class_var_2, ..., class_var_n)

where size_variable precedes the occurrence of the class variable in the

argument list and class_var_i members are referenced in the MACRO body

by means of a subscript:

class var i (3)

'I 331
306 - MACRO

In the MACRO statement, the size_variable is used to identify the class

variable collection being defined. In the MACRO body, the size_variable

indicates the number of sets of class variable members that are included (i.e. the number of times the class variable collection is to be repeated).

A simple class variable example is:

N0TEM1, ITEM2, ITEM3, ITEM4)

which specifies a class variable collection with four members. For an

instance of the MACRO, using the example class variable with N equal to 3, three sets of class variable data for the collection are available to the macro

body statements. The parameter list for the associated MACRO instance is:

ITEMl(l), ITEM2(1), ITEM3(1), ITEM4(1),...,ITEM3(3), ITEM4(3)

Each value for each member of the class variable may be referenced

individually:

ITEM 1(1), ITEM 1(2), ITEM 1(3), ITEM 1(4), etc.

in any order, or implicitly, by using an index variable, e.g., 3:

ITEM3 (3) with 3 ranging from 1 to 3

Use of the class variable to represent a MACRO with a parameter list

identical to the Views Visible Associativity, Form 4, would be specified as:

306, MACRO,681, N1,N2,N1(//DEV,LF,//DEF,IPN,LW),

N2(#DE),N,N(#DEA),M,M(#DEP);

where N1(#DEV,LF,//DEF,ICN,LW) indicates the blocks of views visible,

line font, color number, and line weight information;

N2(#DE) contains the pointers to the entities included in the view;

N(#DEA) contains the back pointers/text pointers; and

M(#DEP) contains the pointers to properties.

332
306 - MACRO

Note that zero is a valid value for a size_variable in a MACRO instance.

ENDM statement

ENDM signifies the end of a MACRO. The form of an ENDM statement is:

ENDM;

All MACROS must have an ENDM statement as their last statement. ENDM

is not implied by the end of the parameter data section.

MREF statement

The MREF statement is used to reference another MACRO from inside a MACRO definition. The form of an MREF statement is:

MREF, ptr, entity type number, argument list;

where "ptr" may be either a pointer variable or an integer expression. The

value is the sequence number of the directory entry record of the MACRO

definition being referenced. "Entity type number" is the assigned entity

number of the MACRO being referenced. "Argument list" is exactly like

that of a SET statement. The effect of the argument list is to replace the

symbolic names found in the MACRO definition with the values of the

expressions contained in the MREF statement, so that execution of the

referenced MACRO will start with the appropriate values. Note that MREF

does not start expansion of the referenced MACRO. Rather it creates an

entity entry which may later be expanded. It is thus not possible for a MACRO being referenced to have access to any of those values except for

those in the argument list. (All variables not in the argument list are treated

as local variables.) Even then, it is not possible for the occurrence of a MREF statement to alter any of those values.

333
306 - MACRO

Examples of MREF statements:

MREF,//macl,600,X1,Y1,Z1,X2,Y2, 3.1; MREF,33,621,A,B,3+X/W+l,6*W,3.,0,6Hstring,$x;

It is not strictly necessary for the values in a MREF statement to be of the same type as the values in the definition MACRO, within certain limitations.

Integer, real, and double precision real values may be freely mixed, although

it might be considered a good idea not to do so. String values may only

appear where string variables appear in the definition.

4. 3. 6. 4 MACRO Instance Entity. A MACRO instance entity is used to invoke a MACRO. The parameter data records of the instance contain values for the

arguments to the MACRO. This is similar to a standard entity entry.

The directory entry for a MACRO instance entity contains the attribute

values that are to be used as the default values during the expansion of the

MACRO. The only special field is the structure field (directory entry field

3), which contains a pointer to the directory entry of the MACRO definition.

The pointer is preceded by a minus sign.

4. 3. 6. 4.1 Directory Data

ENTITY TYPE As defined for each MACRO in the range 600 to 699 or NUMBER: 10000 to 99999.

Structure field: Pointer to directory entry of MACRO definition, pre- ceded by a minus sign.

Other attributes: Default values to be used during expansion of the

MACRO. Attributes listed as defaulting to /HDR

obtain their values from here. (See discussion of LET

statement (attributes) in Section 4. 3. 6. 3. 3.)

334
306 - MACRO

4. 3. 6. 4. 2 Parameter Data

The parameter data section for an instance has the following form:

(Note that, as with all parameter data entities, the first record begins with

the entity type number as defined in the MACRO.)

Index Name Type

1,...K As appropriate for the

particular MACRO

Additional pointers as required (See 2. 2. 4.4. 2)

4. 3.6.5 Examples of MACRO usage.

Five examples are given to illustrate some of the capabilities of a MACRO.

1. Isosceles Triangle

2. Repeated Parallelograms

3. Concentric Circles

4. Ground Symbol

5. Useful Features

Example 1:

The following MACRO definition creates an isosceles triangle, given a vertex

point, a base width, a height and a scale.

Directory Data

ENTITY TYPE NUMBER: 306

Description

The values for the arguments to the MACRO.

They must agree in format

and number with the

arguments in the MACRO

statement of the

definition.

335
306 - MACRO

Parameter Data

306, MACRO, 621, XI, Yl, Al, A2, K; LET Z = 0;

SET //Line 1 = 110,X1,Y1,Z,X1+(K*A1),Y1+(K*A2/2.),Z,0,0;

SET #Line2 = 110,X1+(K*A1),Y1+(K*A2/2.),Z,

X1+(K*A1),Y 1-(K*A2/2.),Z,0,0;

SET #Line3 = 1 10,X1+(K*A1),Y1-(K*A2/2.),Z

X 1,Y 1,Z,0,0;

ENDM;

The MACRO can be used to create a triangle by using a MACRO instance which supplies

the needed values for XI, Yl, Al, A2, and K. The parameter data section for the MACRO

instance would have the following format:

Index Name Type Description

1 X Real X coordinate of vertex

2 Y Real Y coordinate of vertex

3 Al Real Height of triangle

k A2 Real Base of triangle

5 K Integer Scaling factor

336
306 - MACRO

In particular, to create a triangle shown in Figure 4-32 with a base of 5. and a height

of 17., a vertex at (0,0), and a scale factor 1, the following instance could be placed

into the file:

Directory Data:

ENTITY TYPE NUMBER: 621

Structure: -nnn, where "nnn" is the sequence number of the directory entry of the

definition.

Other attributes: As desired for default values during MACRO expansion.

Parameter data:

621, 0., 0., 17., 5., 1;

FIGURE 4-32 EXAMPLE OF TRIANGLE MACRO

337
306 - MACRO

Example 2: Repeated parallelograms

The following MACRO takes the coordinates of three points and a repetition number

as arguments and creates a pattern of repeated parallelograms as shown in Figure 4-

33. The three points represent the vertices of the initial parallelogram. The

repetition number argument (NTANG) controls how many additional parallelograms

will be drawn offset in the positive X and Y direction from the initial one. For

simplicity, the points have been constrained to all lie in a plane parallel to the X-Y

plane.

Directory Data

ENTITY TYPE NUMBER: 306

Parameter Data

306, MACRO, 600, XI, Yl, X2, Y2, X3, Y3, Z, NTANG;

IF NTANG.EQ.0, GOTO &END;

LET XDEL = (X2-X1)/NTANG;

LET YDEL = (Y3-Y D/NTANG;

LET K = 0; REPEAT NTANG +1; SET #VLINE = 1 10,X1+K*XDEL,Y 1+K*YDEL,Z,

X2+K*XDEL,Y2+K*YDEL,Z,0,0;

SET #HLINE = 110, X1+K*XDEL,Y1+K*YDEL,Z,

X3+K*XDEL,Y3+K*YDEL,Z,0,0;

SET //VLINE = 1 10,X3+K*XDEL,Y3+K*YDEL, Z,

X3+(X2-X 1)+K*XDEL,Y2+(Y3-Y 1)+K * YDEL,

Z, 0,0;

SET #HLINE = 1 10, X2+K* XDEL,Y2+K* YDEL, Z,

X3+(X2-X 1)+K*XDEL,Y2+(Y3-Y 1)+K* YDEL,

Z, 0,0;

LET K = K + 1; CONTINUE;

LABEL &END;

ENDM;

338
306 - MACRO

Parameter Data for an instance of this MACRO looks like this:

600, 1., 1., 2., 5., 5., 2., 1., 3;

FIGURE 4-33 REPEATED PARALLELOGRAMS

339
306 - MACRO

Example 3: Concentric circles

The following MACRO, given a coordinate, a radius, and a number, creates

concentric circles out to the radius. A point is put into the center. Figure 4-34

shows the result.

Directory Data

ENTITY TYPE NUMBER: 306

Parameter Data

306, MACRO,601,XC,YC,ZC,R,NCIRC;

IF NCIRC .EQ. 0, GOTO <5cEND;

LET DELTR = R/NCIRC;

REPEAT NCIRC;

SET //CIR = 100,ZC,XC,YC,XC,YC+R,XC,YC+R,0,0;

LET R = R - DELTR;

CONTINUE;

SET #PT = 116, XC, YC, ZC, 0, 0, 0; LABEL &END;

ENDM;

Parameter Data for an instance of the MACRO which would create four concentric

circles around the origin out to a radius of 20 looks like this:

601, 0., 0., 0., 20., 4;

340
306 - MACRO

FIGURE 4-34 CONCENTRIC CIRCLES

341
MACRO

Example 4: Electrical ground symbol

This MACRO takes a point and a base length and constructs a ground symbol

(horizontally) at that point. Figure 4-35 shows the result.

306,MACRO, 602, X, Y, Z, B; IF B.EQ.O, GOTO <5cA; LET DELY = B/6;

LET DELX = DELY;

SET //LINE1 = 110, X, Y, Z, X+B, Y, Z, 0, 0; SET //LINE2 = 110, X+DELX, Y-DELY, Z, X+B-DELX, Y-DELY, Z, 0, 0; SET #LINE3 = 1 10,X+2*DELX,Y-2*DELY,Z,X+B-2*DELX,Y-2*DELY,Z,

0 , 0; LABEL <5cA; ENDM;

Parameter Data for an instance of this MACRO looks like this:

602, 1 ., 6., 2., 1 .3;

FIGURE 4-35 GROUND SYMBOL
306 - MACRO

Example 5: Useful features

This last example demonstrates the use of various MACRO features. It is not meant

as an example of a "useful" MACRO.

Directory Data

ENTITY TYPE NUMBER: 306

Parameter Data

306, MACRO,613,NROW,NCOL,VDIST,HDIST,'.ANGLE;

LET/LABEL = 6HPOINTS;

LET ! SIN =DSIN(! ANGLE); LET !COS=DCOS(!ANGLE);

LET YHD=HDIST*!SIN;

LET XHD=HDIST*!COS;

LET YVD=VDIST*!COS;

LET XVD=VDIST*(-!SIN);

LET IRC=0; LET ICC=0;

REPEAT NROW;

LET XCOL=IRC*XVD;

LET YCOL=IRC*YVD;

REPEAT NCOL;

LET X = XCOL + ICC*XHD;

LET Y = YCOL + ICC*YHD;

SET #PT = 116, X, Y, 0., 0,0,0;

LET ICC = ICC + 1; CONTINUE;

LET IRC = ICC +1; CONTINUE;

LET $NPTS = STRING(NROW*NCOL,17); LET/LABEL = $NPTS;

SET #LINE = 110, 0., 0., 0., 10., 0., 0.; SET #CIRC = 100, 0., 0., 0., 10., 0., 10., 0.; MREF, 22, 601, 0., 0., 0., 10., 5; ENDM;

Parameter Data for an instance of this MACRO looks like this:

613, 4, 5, 0. 2, 0.1, 7.85398D-01;

343
406 - PROPERTY

4.3.7 Property Entity.

The property entity contains numerical or textual data. It also has a form

number to indicate its meaning. Certain generic Property form numbers are described in the following sections and are expected to be augmented by

others in future versions of this Specification. Form numbers in the range

5001 - 9999 are left undefined for users.

Note that properties can also point to other properties, as well as participate

in associativities, point to related general notes, or display text by pointing

to a Text Display Template.

Property instances are usually referenced by the presence of a pointer to the

instance in the second group of additional pointers as described in section

2.2. 4. 4. 2; however, as stated in section 1.5.1, when an instance is independent

it applies to all entities on the same leel as the instance.

4.3.7.

1

Directory Data

ENTITY TYPE NUMBER : 406

4. 3. 7.

2

Parameter Data

Index Name IXPe

1 N Integer

2 Variable

Description

Number of property

values

Property values

1+N

Additional Pointers as required (see 2. 2. 4. 4. 2).

344
406, Form 1 DEFINITION LEVELS

4.3.7.3 Defined Properties

4.3. 7. 3.1 FORM NUMBER: 1 Definition levels

DESCRIPTION

For one or more entities in the file that are defined on a set of multiple levels,

there will be an occurrence of the property instance (Form 1). In the parameter

data portion of the property instance, the first parameter, Nl, will contain the

number of multiple levels followed by a list of those levels. Each entity that is defined on this set of levels will contain a pointer (in the level field of the

directory entry) to this property instance. A different set of multiple levels will

result in a different property instance.

Index Name TyPe Description

1 Nl Integer Number of property values

2

•

•

•1+N1

L Integer Level number

Additional Pointers as required (see 2. 2. 4. 4. 2)

345
406, Form 2 - REGION RESTRICTION

4.3.7.3.2 FORM NUMBER: 2 Region Restriction

DESCRIPTION

This property allows entities that can define regions to set an applications

restriction over that region. The restrictions will indicate whether a given

applications item must lie completely within regions with this property or completely outside such regions. The restriction applies to all points of entities

used to represent the applications item and to all points within the effect of the

item when sill properties, such as line widening, are applied.

Each of the property values in this property will have one of three values indicating

the region restriction relevant to the application's item.

Property Value

0

1

2

Description

No Restriction

Item must be inside region

Item must be outside region

Index Name IlEe

1 NP Integer

2 EVR Integer

3 ECPR Integer

4 ECRR Integer

Description

Number of property values (NP=3)

Electrical vias restriction (EVR=0,1 or 2)

Electrical components

restriction (ECPR=0,1 or 2)

Electrical circuitry

restriction (ECRR=0,1 or 2)

Additional Pointers as required (see 2. 2. 4. 4. 2)

346
406, Form 3 - LEVEL FUNCTION

4. 3. 7. 3. 3 FORM NUMBER: 3 Level Function

DESCRIPTION

This property is used to transfer the meaning or intended use of a level in the

sending system. An instance of this property shall apply to all entities in the same

file with the same DE level value (field 5), without the requirement of a pointer to

it (see section 1.5.1). Parameter 2 is used to record an integer code number when

the sending system uses a level-use index or table. Parameter 3 is used to record

the level-use text, whether such text is obtained from the index which provided

parameter 2, or exists independently. Either parameter 2 or parameter 3 may have

a default value. This property may be readily added to a file (by edit or data

merge) when level-use information is required by the receiving system or archive.

The parameter (2 and 3) values of an instance of this property shall apply to multiple levels if the instance's level value is a pointer to an instance of Property

Form 1. Note that parameter 3 was an integer value for "source level" in Version

2. The source level (for this Version) shall be the level value for the instance of

this property.

Index Name Tyjgg Description

1 NP Integer Number of property values

(NP=2)

2 FC Integer Function description code

(Default = 0)

3 FD String Function Description

(Default = null string)

Additional Pointers as required (see 2. 2. 4. 4. 2)

347
406 , Form 4 - REGION FILL

4.3. 7. 3. 4 FORM NUMBER: 4 Region Fill Property

DESCRIPTION

This property helps define the functional value of any closed region. It classifies

the region as to its "filled" status. It will be used most often to identify which

region-defining entities are defining a functional region (or a gap in that region)

and which have other purposes. The actual function of the region will likely be

determined in conjunction with level or subfigure membership.

Index Name TyPe Description

1 NP Integer Number of property values

(NP=2)

2 FC Integer Fill code:

0 solid fill

1 unfill (i.e., a gap in solid

fill) 2 meshed fill (indicates

that an associativity is used to link the fill area

with its fill mesh

description). Using the

associativity will allow the

implementation of this obsolete method. The

recommended method of

mesh fill is to use Sectioned Area entity

(230).

3 O Pointer Obsolete. Note: a previous

implementation of this

parameter was as a pointer

to the DE of a section

entity defining linear

segments of meshed fill. This previous

implementation would be

indicated by a non- zero

value.

Additional pointers as required (see 2. 2. 4. 4. 2).

348
406, Form 5 - LINE WIDENING

4. 3. 7. 3. 5 FORM NUMBER: 5 Line Widening

DESCRIPTION

This property defines the characteristics of entities when they are used to define

the location of items such as strips of metalization on printed wiring boards.

The justification flag terminology is interpreted as follows: right justified means

that a defining line segment forms the right edge of the widened line in the

direction from first defining point to second. Left justified is the opposite while

center justified indicates that the defining line segment splits the widening exactly

in half. Figure 4-36 indicates the measurement of the property values.

Index Name Iy_gg Description

1 NP Integer Number of property values

(NP=5)

2 WM Real Width of metalization

3 CC Integer Cornering codes

0 rounded

1 squared

4 EF Integer Extension flag

0 No extension

1 One-half width extension

2 Extension set by

parameter

5 3F Integer 3ustification flag

0 center justified

1 left justified

2 right justified

6 E Real Extension value

parameter 4=2 (Note: this value

may be negative)

Additional Pointers as required (see 2. 2. 4. 4. 2)

349
406, Form 5 - LINE WIDENING

Z => woo

m

350

FIGURE

4-36

LINE

WIDENING

EXAMPLES
406, Form 6 - DRILLED HOLE

4. 3. 7. 3. 6 FORM NUMBER: 6 Drilled Hole

DESCRIPTION

The Drilled Hole property identifies an entity representing a drilled hole through a

printed circuit board. The parameters of the property define the characteristics of

the hole necessary for actual machining. The layer range indicated by parameters

5 and 6 refers to physical layers of the assembled printed circuit board.

Index

1

Name

NP

TyPe

Integer

Description

Number of property values

(NP=5)

2 DDS Real Drill diameter size

3 FDS Real Finish diameter size

4 PF Integer Plating indication flag

(0=no, l=yes)

5 LNL Integer Lower numbered layer

6 HNL Integer Higher numbered layer

Additional Pointers as required (2. 2. 4. 4. 2)

351
406, Form 7 - REFERENCE DESIGNATOR

4. 3. 7. 3. 7 FORM NUMBER: 7 Reference Designator

DESCRIPTION

The Reference Designator property attaches a text string containing the value of a component reference designator to an entity being used to represent a component.

This property is not to be used for the primary reference designator when a component

is represented by a Network Subfigure Instance as that value is included in the

subfigure parameters.

Index Name Type Description

1 NP Integer Number of property values

(NP= 1)

2 RD String Reference designator text

Additional Pointers as required (see 2. 2. 4. 4. 2)

352
406, Form 8 - PIN NUMBER

4. 3. 7. 3.8 FORM NUMBER: 8 Pin Number

DESCRIPTION

The Pin Number property attaches a text string representing a component pin

number to an entity being used to represent an electrical component's pin. This

property is not to be used when a pin is represented by a Connect Point entity as the pin number is included in one of the Connect Point parameters.

Index Name TyPe Description

1 NP Integer Number of property values

(NP=1)

2 PN String Pin Number Value

Additional Pointers as required (see 2. 2. 4. 4. 2)

333
406, Form 9 - PART NUMBER

4.3.7.3.9 FORM NUMBER: 9 Part Number

DESCRIPTION

The Part Number property attaches a set of text strings that define the common

part numbers to an entity being used to represent a physical component. Null text values in any parameter will imply that the missing value is not relevant to the

transferred data.

Index Name TyPe Description

I NP Integer Number of property values

(NP=4)

2 GPN String Generic part number or name

3 MPN String MIL-STD part number

4 VPN String Vendor part number or name

5 IPN String Internal part number

Additional Pointers as required (see 2. 2. 4. 4. 2)

354
406, Form 10 - HIERARCHY

4.3.7.3.10 FORM NUMBER: 10 Hierarchy

DESCRIPTION

The hierarchy property provides the ability to control the hierarchy of each

directory entry attribute. This property is referenced when the directory entry

status digits 7 and 8 are 02.

Index

1

Name

NP

TyPe

Integer

Description

Number of property values

(NP=6)

2 LF Integer Line font

3 VU Integer View

4 LAB Integer Entity level

5 BL Integer Blank status

6 LW Integer Line weight

7 CO Integer Color number

Additional Pointers as required (see. 2. 2. 3.4. 2).

Acceptable values for parameters 2 through 7 are 0 and 1. See definition in section 2. 2. 4. 3. 9. 4.

355
406, Form 11 TABULAR DATA

4.3.7.3.11 FORM NUMBER: 11 Tabular Data

DESCRIPTION

The tabular data property provides a structure to accommodate point form data.

The basic structure is a two dimensional array organized in column row order. In the simplified form this structure can contain a single list of values. The more

complex forms contain multiple lists of independent and dependent variables.

The PROPERTY TYPE is the key used to define the dependent variable data

values.

PROPERTY TYPES 1 to 5000 are reserved for defining finite element material

properties.

The units used in these properties are specified in the MKSA (Meters, Kilograms,

Seconds, Ampere) system according to the following table:

Length = meters

Mass = kilograms

Time = seconds

Current = amperes

Energy = joules

Force = newtons

DE Form Number 11 = Tabular Data Property

Index Name Type Description

1 N Integer // of Property values

2 PTYPE Integer Property Type

1 = Young's Modulus

ND=3

2 = Poisson's Ratio

ND=3

356
406 , Form 1

1

TABULAR DATA

3 = Shear Modulus

ND=3

4 = Material Matrix

ND=21

5 = Mass Density

ND=1

6 = Thermal Expansion

Coefficient

ND=3

7 = Laminate Material

Stiffness Matrix

ND=6

8 = Bending Material

Stiffness Matrix

ND=6

9 = Transverse Shear

Material Stiffness

Matrix

ND=3

10 = Bending Coupling

Material Stiffness

Matrix

ND=6

11 = Material Coordinate

System

ND=3

12 = Nodal Load/Constraint

Data ND=// of Degrees

of Freedom

13 = Sectional Properties

for Beam Elements

ND=8 if the properties are the same at both

ends of the beam

other wise,

ND=16

14 = Beam End Releases

ND=12

357
406 , Form 1

1

TABULAR DATA

15 = Offsets

ND=9 or 18

16 = Stress Recovery Information

ND=12 or 24

17 = Element Thickness

ND=1 or n

18 = Non-Structural Mass

ND=1

19 = Thermal Conductivity

ND=3

20 = Heat Capacity

ND=1

21 = Convective Film Coefficient

ND=1

22 = Radiation Parameters

ND=4

n = Open Ended

3 ND Integer # of dependent variables

4 NI Integer // of independent variables

5 TYPi Integer Type of first independent

variable

1 = Temperature

2 = Pressure

3 = Relative humidity

4 = Rate of Strain

5 = Velocity

6 = Acceleration

7 = Time

8 = Strain

n = Open Ended

4+NI TYPNI Integer Type of last independent

variable

358
406, Form 11 TABULAR DATA

Index Name TyPe Description

5+NI NVALIi Integer Number of different values of

the first independent

variable

4+2*NI nvali ni Integer Number of different values of

the last independent

variable

5+2*NI VALI \ Real First value of first independent

variable

vali ni Real Last value of last independent

variable

M+l VALD (j,k) Real Value of the dependent variable

where

NJ NI

M + ND • NVAL1, = M+ ND

'—

• a J-I...ND. k-1... NVALlj

i-1 N+ 1 '- 1

a a

VALD (1,1) = f, (VALI,(1), VALI2 (1), VALIW(1))

VALD (ND,1) = fNO (VALI,(l), VALIKO))

VALD (1,2) = f](VALI,(2), VALI W(1))

VALD (ND,2) = f^(VALI,(2), VALI/v/O))

VALD (l,a) = f^VALI^NVALl,) VALI m (NVALI*/))

VALD(ND,a) = fNO (VALI,(NVALl,

)

VALl/y/ (NVALI/v/))

Additional Pointers as required (see 2.2AA.2).

359
406, Form 11 TABULAR DATA

MATERIAL PROPERTY TYPE DEFINITIONS:

PTYPE = 1 Young's Modulus

Young's modulus relates stress to strain in materials. In the simple case:

a = E e

Where cr?EStress Vector (Row of Elements ct x, <r y , cr ,) Strain Vector (Row of Elements e x , e y , e z ) Young’s Modulus Matrix of Diagonal Elements

Exx^ yy

and Ezz

The modulus is a vector with three principal values E xx , Eyy, and Ezz. This implies

that ND (Number of Dependent Variables) is equal to three.

In matrix form:

O-x C* ay = 0 Eyy 0 «>-

<*Z 0 0 Eu

360
406, Form 11 TABULAR DATA

PTYPE = 2 Poisson's Ratio

Poisson's ratio is the ratio of transverse strain in the j-direction when stressed in the i-direction, i.e.,

Where v = Poisson’s Ratio

€ = Strain

i = One Orthogonal Direction

j = Another Orthogonal Direction

The Poisson's Ratio is a vector consisting of matrix elements with the three

principal values, Vxy> ^XZ> ^YZ

The other off diagonal matrix values are reciprocals of the principal values.

i.e., vXy

1 Vyx

This implies that ND (Number of Dependent Variables) is equal to three.

In matrix form for an orthotropic material:

1 Vyx F

* C-yy E

Vxy 1 €

y ’ E^XX %E

VX7_ Vyz_

’ EXX

‘ l-y2 E

Vzx

‘ Exx v x

V Zy

' EXX

<Jy

1 EZZ <7x

361
406 Form 11 - TABULAR DATA

PTYPE = 3 Shear Modulus

Shear Modulus - The ratio of shear stress to shear strain.

G =

Jj_

y

Where G is the Shear Modulus,

Tj is the Shear Stress, and

y is the Shear Strain

The Shear Modulus is a vector with three princpal values:

C*xy,> Gyx> anc* Gxz*

This implies that the ND (Number of Dependent Variables) is equal to three.

In matrix form for orthotropic materials:

1 y*y Gxy y* = 0

7zx 0

0

1 Gyz

0

0

0

1

362
406, Form 11 - TABULAR DATA

PTYPE = 4 Material Matrix

Material matrix defines the tensor qualitites of the material. For example:

5= -|C|«

Where <

t

is the Stress Vector,

? is the Strain Vector, and

| C | is the Material Matrix

Because of symmetry, the elements Cjj. = Cm. Therefore, 21 elements define the

material matrix.

cn C44 c46

c 12 c 15 ^56

c22 c25 c66

c 13 ^35

c23 C45

C33 c55

c 14 c 16

c24 C26

C34 C36

This implies that ND = 21.

In Matrix form:

Cll ^12 ^13 c14 C15 ^16

(Ty Qi C22 ^23 C24 Q5 ^26

<Tz C31 C32 C33 C34 Q5 ^36

Txy C41 C42 C43 C44 C45 C46

C51 ^52 ^53 C54 C55 ^56 >V

Tzx Qi ^62 Q3 Q4 Q5 Q6 7zx

363
406, Form 11 - TABULAR DATA

PTYPE = 5 Mass Density

Mass density is the Mass/Unit Volume.

This implies that ND = 1.

Mass Density ity == ^

PTYPE = 6 Thermal Expansion Coefficient

THERMAL EXPANSION COEFFICIENT is a material property that computes the

strain given a temperature differential, i.e.,

c •* a A T or a “= —=

Where « — strain a *= thermal expansion coefficient AT— the temperature differential

The THERMAL EXPANSION COEFFICIENT may be represented as a vector with

three principal values:

axx» ayy

anc^ azz*

This implies that ND (number of Dependent Variables) is equal to three.

364
406 , Form 1

1

TABULAR DATA

PTYPES 7-11 Composite Materials

Composite materials will be represented with linkages to Tabular Data Property 11

as described in Figure 4-37. PTYPES required are:

PTYPE DESCRIPTION

7. Laminate material stiffness matrix

8. Bending material stiffness matrix

9. Transverse shear material stiffness matrix.

10. Bending coupling material stiffness matrix.

11. Material Coordinate System.

PROPERTY

POINTERS

l PLUS OTHER

f APPLICABLE PTYPES

FIGURE 4-37 COMPOSITE MATERIAL CONFIGURATION

365
406, Form 11 TABULAR DATA

PTYPE = 7 Laminate Material Stiffness Matrix

The membrane material stiffness matrix defines anisotropic material properties for

shell =membrane action. For example:

7 = t [M] 1

Where f = Forces per unit length row of elements (fx , fy , /^)

c = Midplane strains row of elements (e x , e y , c^)

t — Shell thickness — see element property

[M] = Membrane material stiffness matrix

F and e Defined in shell material coordinate system, PTYPE — 1

1

Because of symmetry, the elements Mji = Mij. Therefore, six elements define the

membrane material stiffness matrix. This implies ND = 6.

Mn

m 12

M B

M22

M23

M33

The matrix |mJ is a laminate material stiffness matrix which is calculated from

lamina stress strain matrices (cij| n

. One method for calculating [mJ for a laminate

containing m plys is:

1 m

[Mij] = - £ [Gij] n A tn "- 1 A tn

is thickness of n'

h

t is total thickness of laminate

Where |Gr)n

is stress strain matrix for n^ ply of laminate, defined in the

material coordinate system

366
406, Form 11 TABULAR DATA

PTYPE = 8 Bending Material Stiffness Matrix

The bending material stiffness matrix defines the anisotropic material properties

for shell bending. For example:

Where m

m - ~{B)x

Shell bending moments per unit length (Row of elements Mx, My Shell curvature (Row of elements (*,, \y , Xxy)

Shell thickness — see element property

Bending material stiffness matrix M and x are defined in shell material coordinate system, PTYPE —11

Because of symmetry the elements Bij = Bji. Therefore, six elements define the

bending stress strain matrix. This implies ND = 6

Bn

b 12

b 13

B2 2 B2 3

b33

The matrix [b] is a laminate matrix for bending, which is calculated from lamina

matrices [G] n. One method for calculating [b] for a laminate containing m plys is:

[Bij] £ (Zn

2 [Gij] n Arfl )

Where [G]„ is stress strain matrix of lamina for n'

h ply of laminate, defined in the

shell material coordinate system

A tn is thickness of n'

h ply

Z„ is the normal distance from midplane of shell to centroid of ply

/ is total thickness of shell

367
406 , Form 1

1

TABULAR DATA

PTYPE = 9 Transverse Shear Material Stiffness Matrix

The transverse shear material stiffness matrix defines anisotropic material

properties for transverse shear flexibility in shell structure. For example:

V-ts [ 5] y

Where V = transverse shear force per unit

length (row of elements Vx, Vy

)

y = transverse shear strains, dimensionless

(Row of elements ( yx , yy

)

ts — effective transverse shear thickness

[S] = transverse shear material stiffness matrix

V and y are defined in material coordinate system

Because of symmetry Sij = Sji. Therefore, three elements define the transverse

shear material stiffness matrix. This implies ND = 3.

S 11 s 12

$22

The matrix £sj is a laminate material stiffness matrix for transverse shear

flexibility. If the matrix is not defined, deflections normal to the shell do not include contributions from transverse shear strain.

368
406, Form 11 TABULAR DATA

PTYPE = 10 Bending Coupling Material Stiffness Matrix

The membrane - bending coupling material stiffness matrix defines the anisotropic

material properties for shell structure with the neutral axis for bending offset from

the midplane of the shell. For example:

7 - f IC] a

and

m - t 7 ICF*

Where / — Forces per unit length (row of elements fx , fy, f^)

m -= Bending moments per unit length (row of elements mx , my , m^)

X

-= Curvature (measurements of bending strain), units

(meter)

-1 (Row of elements Xx , Xy , X^)

e «= Midplane strains (row of elements «

t — Shell thickness

f,m,x and ? are defined in the shell material coordinate system

Because of symmetry, the elements Cij = Cjj. Therefore, six elements define the

membrane bending coupling material matrix. This implies ND = 6.

C 11 c 12

c 13

c22

c23

C33

369
406, Form 11 - TABULAR DATA

PTYPE =10 (Continued)

The matrix |c| is a laminate matrix for membrane bending coupling, which is calculated from lamina stress strain matrices Mn- One method for calculating |cj

for a laminate containing m plys is:

lev

)

-J I (Z. lGlj] n Ar„) ^ n—

1

Where lG]„ is stress strain matrix for n'* ply, defined in shell material coordinate system

A t„ is thickness of n‘

h ply

Z„ is the normal distance from midplane of shell to centroid of ply

t is thickness of shell

370
406, Form 11 TABULAR DATA

PTYPE =11 Material Coordinate System

The orientation of the element material coordinate system is specified by a set of

direction cosines defining a vector D. The use of the vector D depends upon the

element type.

For element topology type 1 and 33 of entity type 136, the following Figure 4-38

illustrates the use of the vector D to define the element material coordinate

system. For topology type 33 the vector D is defined by the reference node 3.

FIGURE 4-38 Elemental and Material Coordinate System

The cosines for vector D are translated to the location of the shear center offset

to establish the reference planes for material property definition (vector DT).

For element topology types 2 through 26 of the entity type 136, the following

paragraphs discuss the use of vector D to define the material coordinate system.

The projection of D on the plane of the element face (FI) (outward normal N)

defines a vector in the X direction of the material coordinate system.

x = N x D x N N = positive outward normal of the element face (FI), and is defined by nodal connection of the element, i.e., N - Sjx Sj

5] = vector from first to second corner of element face (FI)

S2 = vector from second to third corner of element face (FI)

371
406, Form 11 TABULAR DATA

PTYPE = 11 (Continued)

Three direction cosines are required to define the Vector D in the global coordinate

system. Therefore, ND = 3.

Dl

D2 d3

The vectors D and N define the element material X and Z axes, respectively. The

internal load and strain sign conventions must be described to ensure consistent

definition of material types 7-10. See Figure 4-39.

INTERNAL LOAD SIGN CONVENTION:

where:

x, y, z are material coordinate

system axes

u, v, w are displacements of a

point in the material

coordinate system.

372
406 , Form 1

1

TABULAR DATA

1

**y

fx

fy

fxy f forces per unit length

€ midplane strains

Mx My

Mty

M moments per unit length

Xx

Xy

Xxy

c bending curvatures

I V transverse shear forces per unit length

y transverse shear strains

STRAIN DISPLACEMENT RELATIONSHIPS

«x

Xx

yx

bu bv

bx'

e> “ by'f *

y

b

7 u b2 W

bx2

' 8V

Xxy

bw b w

bx' by

bu bv

by Bx

2 b

7 w

bxby

FIGURE 4-39 INTERNAL LOAD SIGN

373
406, Form 11 TABULAR DATA

PTYPE = 12 Nodal Loads/Constraints Data

The nodal load/constraint data will be stored in the tabular data property form

number in the following manner:

PTYPE = 12

ND = # of degrees of freedom

For example, if the load vector has an X, Y, Z Mx, My, and Mz components;

the ND=6. (Note Mx , My, Mz refer to moments). If the load- vector has an X

and Y component, the ND=2. If the load vector has only a Z-component, then

ND=3. In other words the X-component is the 1st degree, the Y-component is the 2nd degree, and the Z-component is the 3rd degree. Other components

are treated in a similar manner starting in the 4th degree for the rotation X

component.

The constraint vector has an X, Y, Z, Mx, My, and Mz constraints. These

constraints are represented by a 0 = No Constraint and 1 = Constraint. ND =

6 always for constraints.

374
406, Form 11 TABULAR DATA

PTYPE = 13 Sectional Properties for Beam Elements

Sectional properties for beam elements define the structural characteristics of the

beam. These properties are:

PROPERTY UNITS DESCRIPTION

Area M2 Area of section

lx M4 Area moment of inertia about the

axis

element xV Area moment of inertia about the

axis

element yIxy Product of inertia

3 Torsional stiffness parameter

SRxy Unitless Shear stiffness ratio

SRxz Unitless Shear stiffness ratio

wc M6 Warping coefficient

If the properties are the same at both ends of the beam then ND=8, otherwise

ND=16. If ND=16, two sets of section properties are specified. They are stated in order of the topology set grid number scheme.

375
406, Form 11 - TABULAR DATA

PTYPE = 14 Beam End Releases

Beam end releases specify whether the ends of the beam are constrained or free to move. If free to move then both translation and rotational freedoms of the end are considered.

PROPERTY

FOR

EACH

END

X

Y

Z

Mx

My

Mz

DESCRIPTION

X direction translation freedom/constraint

Y direction translation freedom/constraint

Z direction translation freedom/constraint

X direction rotational freedom/constraint

Y direction rotational freedom/constraint

Z direction rotational freedom/constraint

The value for each property X, Y, Z, M x, My, Mz , is either a O=unconstrained;

+ l=constrained to the global coordinate system; or -l=constrained to the element

coordinate system.

The beam release must be specified at both ends. Therefore, ND=12.

The beam ends are defined by the Topology Set grid number scheme.

376
406, Form 11 - TABULAR DATA

PTYPE = 15 Offsets

Offsets are global x,y,z values used to define the location of the shear center axis,

neutral axis, and non-structural center of mass relative to the element end nodes.

Figure 4-38 shows SCO - "Shear Center Offset";

NAO - "Neutral Axis Offset"; and

NSMO - "Non-Structural Mass Offset".

These offsets are vectors in the global coordinate system (model space) relative to the end of the beam.

PROPERTY DESCRIPTION

~SCOx Shear Center Offset in global x direction

SCOy Shear Center Offset in global y direction

SCOz FORShear Center Offset in global z direction

NAOx EACHNeutral Axis Offset in global x direction

NAOy

END

Neutral Axis Offset in global y direction

NAOz Neutral Axis Offset in global z direction

NSMOx Non-Structural Mass Offset in global x direction

NSMOy Non-Structural Mass Offset in global y direction

NSMOz Non-Structural Mass Offset in global z direction

ND=9 or ND=18 depending on whether or not both ends must be specified. They are

stated in order of the topology set grid number scheme.

377
406, Form 11 - TABULAR DATA

PTYPE = 16 Stress Recovery Information

Stress Recovery Information is used to define up to four offset points at each beam

end at which stress levels will be recovered from the finite element analysis

program.

These offset points are described as global x, y, z offsets from each end node.

All offset points are in a plane which is normal to thebeam element axis.

These points occur in pairs from one end of the beam to the other.

378
406, Form 11 - TABULAR DATA

PTYPE = 16

END1

1st Pair

of Offsets

END2

END1

4th Pair

of Offsets

END2

(Continued)

PROPERTY

SRIfxi

SRI ly 1

SRIlzl

SRl2xl

SRI2yl

SRl2zl

DESCRIPTION

Stress Recovery Information beam end 1 xdirection pair 1

Stress Recovery Information beam end 1 y- direction pair 1

Stress Recovery Information beam end 1 z- direction pair 1

Stress Recovery Information beam end 2 x- direction pair 1

Stress Recovery Information beam end 2 y- direction pair 1

Stress Recovery Information beam end 2 z- direction pair 1

SRIlx4 Stress Recovery Information beam end 1 x- direction pair 4

SRIlyJj Stress Recovery Information beam end 1 y- direction pair 4

SRIiz4 Stress Recovery Information beam end 1 z- direction pair 4

SRI2x4

SRl2y4

SR^2z4

Stress Recovery Information beam end 2 x- direction pair 4

Stress Recovery Information beam end 2 y- direction pair 4

Stress Recovery Information beam end 2 z- direction pair 4

379
406 , Form 1

1

TABULAR DATA

PTYPE = 17 Element Thickness

Element Thickness defines the net section thickness for a homogeneous element or

individual plate thickness for a laminate or sandwich plate. ND=1 or n and is defined as follows:

ND=1 Scalar thickness of element

ND=n Thickness of the nth plate of a sandwich or laminate

The thickness is in the order from 1 to n,

The thicknesses are measured in the positive Z direction in order of increasing z in

local element coordinate system.

PROPERTY DESCRIPTION

tj Thickness for homogeneous plate or the thickness for the

first lamina of the plate

tn Thickness for the nth lamina of the plate.

380
406, Form 11 - TABULAR DATA

PTYPE = 18 Non-Structural Mass

Non-Structural Mass is defined as the mass not accounted for in volume and density

information for the structural elements. ND=1.

PROPERTY DESCRIPTION

NSM Mass/unit length or Mass/unit area or Mass/unit volume

this depends on type of element.

381
406, Form 11 - TABULAR DATA

PTYPE = 19 Thermal Conductivity

Thermal Conductivity relates heat flow across a surface as a function of

temperature. The heat balance equation shows this relationship:

_a_ ex

Where

- Q,

k„ — Thermal conductivity coefficient where n-x,y,

z

Cp - Heat capacity at constant pressure

p - Material Density

T — Temperature

t — Time

Qi — Energy converted to heat internally

x,y,z are defined in the local element coordinate system.

If we consider k (thermal conductivity coefficient) as independent of direction,

then k can be represented as constant in the x, y, z directions:

i.e., iL aH bkx Q T a

2 r

3x * dx\ dx 8x kx

Now assuming a constancy in the x direction:

91

dx ' dx

d

2 r

dx2

Therefore the thermal conductivity is a vector with three principal values, k x , k

y

, and k z

. This implies that ND (Number of Dependent Variables) is equal to three.

382
406 , Form 1

1

TABULAR DATA

PTYPE = 19 Thermal Conductivity (Continued)

In matrix form for constraint conductivity:

kx ky kz

b

2 T

bx2

d

2 T

by2

b

2 T

bz1

r

dT n

Now assuming no internal heat sources Qj and the steady state where = Q

Consequently, integrating in one direction

Q

- k- A f,

Where Q is the heat flux in the x direction across a surface of area A normal to the

x-direction. Likewise solutions may be found in the y and z direction.

PROPERTY DESCRIPTION

Kx Thermal Conductivity coefficient x direction

Ky Thermal Conductivity coefficient y direction

Kz Thermal Conductivity coefficient z direction

383
406, Form 11 - TABULAR DATA

PTYPE = 20 Heat Capacity

Heat Capacity is a material's ability to store heat. The heat balance equation

shows the relationship of heat capacity to the spatial variation and time variation

of temperature.

JL

8x

* 91

+ fdy

k X btI i

dx y 8z

kz oz = P

Where

kn «= Thermal conductivity coefficient where n=x,y,z

Cp = Heat capacity at constant pressure

p

«= Material Density

T = Temperature

t *= Time

Q, *= Energy converted to heat internally

If we consider constant pressure, the heat capacity can be considered a constant.

Consequently, ND=1 to define the constant.

PROPERTY DESCRIPTION

Cp Heat capacity at constant pressure

384
406, Form 11 TABULAR DATA

PTYPE = 21 Convective Film Coefficient

Convective film coefficient relates to the amount of heat flux that is conveted to adjacent materials at the interface boundary of a heat source.

Where Q - the heat flux

hc - the convective film coefficient A — the surface area through which the heat flows AT — the Temperature differential between the materials.

The convective film coefficient may be represented as a constant. This implies

that ND=1.

PROPERTY DESCRIPTION

hc Convective Film Coefficient

PTYPE = 22 Electromagnetic Radiation Parameters

Properties for Absorptivity, Transmissivity, Reflectivity, and Emissivity are defined for structural elements using four values. ND=4.

Q - - hcA AT

PROPERTY DESCRIPTION

a Absorptivity Constant

t Transmissivity Constant

R Reflectivity Constants

E Emissivity Constant

385
406, Form 11 TABULAR DATA

Examples:

Consider the representation of the mass density as a function of pressure:

INDEX NAME RECORDED VALUE

1 N 9

2 PTYPE 5

3 ND 1

4 NI 1

5 TYPI 2

6 NVALI 2

7 VALI i 50

8 vali 2 25

9 VALD(1,1) 33

10 VALD(1,2) 46

Additional pointers as required (see 2. 2. 4. 4. 2)

386
406, Form 11 TABULAR DATA

Examples:

Consider the representation of Young's modulus for a linear, static, independent

case:

INDEX NAME RECORDED VALUE

1 N 6

2 PTYPE 1

3 ND 3

4 NI 0

4 + 2*NI+l = 5 Exx 30 x 106

6 Eyy 30 X 106

7 Ezz 30 x 106

Additional pointers as required (see 2. 2. 4. 4. 2)

387
406, Form 12 - EXTERNAL REFERENCE

FILE LIST

4.3.7.3.12 FORM NUMBER: 12 External Reference File List

DESCRIPTION

The External Reference File List appears in an IGES file which references

definitions that reside in another IGES file. It contains a list of the names of the

IGES files directly referenced by entities within this IGES file. See section 2.5.4 and the External Reference Entity (Type 416) for more detail.

Index Name Type Description

1 N Integer Number of List Entries

2 NAME1 String External Reference File

Name

N+l NAMEN String Last External Reference

File Name

Additional pointers as required (see 2. 2. 4. 4. 2).

388
406, Form 13 - NOMINAL SIZE

4.3.7.3.13 FORM NUMBER: 13 Nominal Size

DESCRIPTION

A nominal size consists of a value, a name and optionally a reference to an

engineering standard. The nominal size value is a real value in the units appropriate

for the specified name. The name is a string constant, but the following values are

predefined:

Nominal Size Name Meaning

3HAWG

3HIPS

2HOD

American Wire Gauge

Iron Pipe Size

Outside Diameter schedule, i.e., tubing

Index Name TyPe Description

1 NP Integer Number of property values

(NP=2 or 3)

2 SZ Real Nominal size value

3 NM String constant Nominal size name

4 SP String constant Name of relevant

engineering standard

(optional)

Additional pointers as required (see 2. 2. 4. 4. 2)

389
406, Form 14 - FLOW LINE

SPECIFICATION

4.3.7.3.14 FORM NUMBER: 14 Flow Line Specification

DESCRIPTION

The flow line specification property attaches one or more text strings to entities

being used to represent a flow line.

Index Name

1 NP

2 LI

3 L2

TyPe

Integer

String constant

String constant

Description

Number of property values

Primary flow line

specification name

Modifier (optional)

NP+1 LN String constant Modifier (optional)

Additional Pointers as required (see 2. 2. 4. 4. 2)

390
406, Form 15 - NAME

4.3.7.3.15 FORM NUMBER: 15 Name

DESCRIPTION

This property contains a string which specifies a user-defined name. It can be used

for any entity that does not have a name explicity specified in the parameter data

for the entity.

Index Name TyPe Description

1 NP Integer No. of property

Values (NP=1)

2 NAME String Entity Name

Additional Pointers as required (see 2. 2.4. 4. 2)

391
406, Form 16 - DRAWING SIZE

4.3.7.3.16 FORM NUMBER: 16 Drawing Size

DESCRIPTION

This property specifies the size of the drawing in drawing units. The origin of

the drawing is defined to be (0,0) in drawing space.

Index Name Type Description

1 NP Integer No. of property Values

(NP=2)

2 XS Real X Size (Extent of Drawing

along positive XD axis)

3 YS Real Y Size (Extent of Drawing

along positive YD AXIS)

Additional Pointers as required (see 2. 2. 4. 4.2)

392
406 , Form 17 - DRAWING UNITS

4.3.7.3.17 FORM NUMBER: 17 Drawing Units

DESCRIPTION

This property specifies the drawing space units as outlined in the drawing

entity (Type 404). The drawing units are given in the same form as the model

space units in the global section (see 2.2.4.2.14).

Index Name Type Description

1 NP Integer No. of Property Values

(NP=2)

2 FLAG Integer Units Flag

3 UNIT String Units Name

Additional Pointers as required (see 2. 2. 4. 4.2).
308 - SUBFIGURE DEFINITION

4.3.8 Subfigure Definitions

The following definition entities are used to provide a "template" for

the instances of subfigures (see 2.5.1).

4.3.8. 1 Subfigure Definition Entity.

The subfigure definition entity is designed to support the concept of a subpicture (if one equates drawing creation with graphics picture

processing). This entity permits a single definition of a detail to be

utilized in multiple instances in the creation of the whole picture. The

contents of the subfigure include a set of pointers to any combination

of entities and other subfigures. DEPTH indicates the actual nesting of

the subfigures. If DEPTH=0, the subfigure has no references to any

subfigure instances. A subfigure cannot reference a subfigure instance

that has equal or greater depth. A DEPTH=N indicates there is a reference to an instance of a subfigure definition with DEPTH N-l.

4.3.8. 1.1 Directory Data

ENTITY TYPE NUMBER : 308

4.3.8.1.2 Parameter Data

Index Name TyPe Description

1 DEPTH Integer Depth of subfigure (indicating the amount of nesting)

2 NAME String Subfigure name

3 N Integer Number of entities in the

subfigure

4 DE Pointer Pointers to the directory en

tries for the associated

entities

N+3 . Pointer Pointer to the last directory

entry

Additional Pointers as required (see 2. 2. 4. 4. 2).

394
320 - NETWORK SUBFIGURE DEFINITION

4.3. S. 2 Network Subfigure Definition Entity

The Network Subfigure Definition entity permits a single definition of a

detail to be used in many instances in the file, similar to the Subfigure

Definition entity (Type 308). It differs from the ordinary Subfigure

Definition in that it defines a specialized subfigure, one whose instances may

participate in networks. To participate in a network, points of connection

(Connect Point entity Type 132) must be defined (see indices NA+7 and

NA+NC+7) and instanced along with the subfigure. Often, products which

contain networks are designed first as schematics (showing the logical

connections or relationships), which are then converted into the designs of

the physical products. Whenever both a logical design and a physical design

are present in the same file, the processor needs a way to determine which

entities belong in which design. The Type Flag field (index NA+4) implements

this distinction. Other fields, such as NAME and DEPTH, function in exactly

the same manner as the Subfigure Definition (308).

Note: the depth of the subfigure is inclusive of both Network Subfigures

entity (Type 320) and the ordinary subfigure entity (Type 308). Thus, the two

may be nested but must indicate that in the depth parameter.

4. 3. 8. 2.1 Directory Data

ENTITY TYPE NUMBER: 320

4.3.8. 2. 2 Parameter Data

Index Name TyPe Description

1 DEPTH Integer Depth of subfigure

(indicating the amount of

nesting)

2 NAME String Subfigure name

395
320 - NETWORK SUBFIGURE DEFINITION

Index Name TyPe Description

3 NA Integer Number of associated (child)

entities in the subfigure

exclusive of Primary

Reference Designator and

connect points.

APTR1 Pointer Pointer to the directory

entry of the first associated

•

entity.

NA+3 APTRNA Pointer Pointer to the directory

entry for the associated

entity NA.

NA+4 TF Integer Type Flag:

0 = not specified

1 = logical

2 = physical

NA+5 PRD String Primary reference designator

NA+6 DPTR Pointer Pointer to the directory

entry of the primary

reference designator Text

Display Template

NA+7 NC Integer Number of associated (child)

Connect Point entities

NA+8 CPTR1 Pointer Pointer to the directory

# # # entry for the associated

• • • Connect Point 1 Connect

NA+NC+7 CPTRNC Pointer Pointer to the directory

entry for the associated

Connect Point NC

Additional Pointers as required (see 2.2AA.2).

396
408 -SUBFIGURE INSTANCE

4.3.9 Subfigure Instances

4.3.9.

1

Singular Subfigure Instance Entity

This entity defines the occurrence of a single instance of the defined

subfigure (Type 308). See Figure 4-40 and Section 2.5.1.

4. 3.9 . 1 . 1 Directory Data

ENTITY TYPE NUMBER: 408

4.3. 9. 1.2 Parameter Data

Index Name Type

1 DE Pointer

2 X Real

3 Y Real

4 Z Real

5 S Real

Description

Pointer to subfigure

definition entry

Translation data relative to either model space or to the

definition space of a

referring entity

II

II

Scale factor (default = 1.0)

Additional Pointers as required (see 2. 2. 4. 4. 2).

4.3.9.2 Rectangular Array Subfigure Instance Entity.

The rectangular array produces copies of an object called the base entity,

arranging them in equally spaced rows and columns. The following types of

entities are valid for use as a base entity: group associativity, point, line,

circular arc, conic arc, parametric spline curve, rational B-spline curve, any

annotation entity, rectangular array instance, circular array instance, or subfigure definition. The number of columns and rows of the rectangular

array, together with their respective horizontal and vertical displacements

are given. Also, the coordinates of the lower left hand corner for the entire

array is indicated. This is where the first entity in the reproduction process

is placed and is called position No. 1. The successive positions are counted

vertically up the first column, then vertically up the second column to the

right, and so on.

397
412 - RECTANGULAR ARRAY

SUBFIGURE INSTANCE

The array of instance locations for the base entity is rotated about the line

through the point (X,Y), parallel to the ZT-axis. The angle of rotation is specified in radians counterclockwise from the positive XT-axis. The

instances of the base entity are not rotated from their original orientation.

A DO-DON'T flag enables one to display only a portion of the array. If the

DO flag is chosen, half or fewer of the elements of the rectangular array are

to be defined. If the DON'T flag is chosen, half or more of the elements of

the rectangular array are to be defined.

4. 3.9.2.

1

Directory Data

ENTITY TYPE NUMBER: 412

4. 3. 9. 2.

2

Parameter Data

Index Name TyPe Description

1 DE Pointer Pointer to base entity

2 S Real Scale factor (default =

1.0)

3 X Real Coordinates of point

4 Y Real

to be used as lower

5 Z Real

left hand corner of

array

6 NC Integer Number of columns

7 NR Integer Number of rows

8 DX Real Horizontal distance

between columns

9 DY Real Vertical distance between rows

10 AX Real Rotation angle in radians

11 LC Integer DO-DON'T list count

=L. (L=0 indicates all to be

displayed.)

398
412 - RECTANGULAR ARRAY

SUBFIGURE INSTANCE

Index Name TYPe Description

12 DDF Integer DO-DON'T flag

(DO=0; DON'T=l)

13 N1 Integer Number of first position to be processed

(DO), or to be processed (DON'T)

12+LC NLC Integer Number of last position

Additional pointers as required (see 2.2AA.2).

399
SUBF

I

GURE

412 SUBFIGURE INSTANCE

400

FIGURE

4-40

SUBFIGURE

ORIGIN
414 - CIRCULAR ARRAY

SUBFIGURE INSTANCE

4. 3. 9. 3 Circular Array Subfigure Instance Entity

The circular array produces copies of an object called the base entity,

arranging them around the edge of an. imaginary circle whose center and

radius are specified. The following types of entities are valid for use as a base entity: group associativity, point, line, circular arc, conic arc, parametric spline curve, rational B-spline curve, any annotation entity,

rectangular array instance, circular array instance, or subfigure definition.

The number of possible instance locations for the base entity is specified and

the location of the first instance position is specified in terms of a radius and

a start angle measured positive, counterclockwise in radians from the line

through the point (X,Y), parallel to the ZT-axis. The successive positions

follow a counterclockwise direction around the imaginary circle and are

distributed according to a given delta angle.

A DO-DON'T flag enables one to display only a portion of the array. If the

DO-flag is chosen, half or fewer of the elements of the circular array are to be defined. If the DON'T-flag is chosen, half or more of the elements of the

circular array are to be defined.

4. 3. 9. 3.1 Directory Data

ENTITY TYPE NUMBER: 414

4. 3. 9. 3.

2

Parameter Data

Index Name lype Description

1 DE Pointer Pointer to base entity

2 NE Integer Total number of

possible instance

locations

3 X Real Coordinates of center

4 Y Real of imaginary circle

5 Z Real

6 R Real Radius of imaginary

circle

7 AS Real Start angle in radians

8 AD Real Delta angle in radians

401
414 - CIRCULAR ARRAY

SUBFIGURE INSTANCE

Index Name Type Description

9 LC Integer DO-DON'T list count = L.(L=0 indicates all replicated entities to be displayed)

10 DDF Integer DO-DON'T Flag

(DO=0; DON'T=l)

11 N

1

Number of first position to be processed

(DO), or to be not pro-

• • • cessed (DON'T)

•

•

10+LC NLC Integer Number of last position

Additional Pointers as required (see 2. 2. 4. 4. 2).

402
420 - NETWORK SUBFIGURE INSTANCE

4.3.9.4 Network Subfigure Instance Entity

Each instance of a Network Subfigure Definition Entity is specified by a Network Subfigure Instance Entity. It functions and may be used as described

in section 2.5.1.

In addition though, the points of connection (connect Point Entity Type 132)

specified by the Network Subfigure Definition Entity must be instanced and

associated with each Network Subfigure Instance (see indices 11 and 12).

The Type Flag field (index 8) implements the distinction between logical

design and physical design data if both may be present in the file.

The Network Subfigure Instance Entity allows different scale factor in the x,

y, and z axes. This scaling is performed before the translation from X, Y,

and Z and before the Transformation matrix entity pointed to in the directory

entry (if any) is applied. The scaling does not apply to the model space

placement coordinates (X, Y, Z).

4.3.9.4.1 Directory Data

ENTITY TYPE NUMBER: 420

4.3.9.4.2 Parameter Data

Index Name Description

1 DE Pointer Pointer to network

definition entry

2 X Real Translation data

relative to either model

space or to the

definition space of a

referring entity

3 Y Real tl

4 Z Real II

403
420 - NETWORK SUBFIGURE INSTANCE

Index Name TyPe Description

5 XS Real Scale factor in definition space x axis

(default 1.0)

6 YS Real Scale factor in definition space y axis

(default XS)

7 ZS Real Scale factor in definition space z axis

(default XS)

8 TF Integer Type flag:-

0 - not specified

1 - logical

2 - physical

9 PDR String Primary reference

designator

10 DPTR Pointer Pointer to the directory

entry of the primary

reference designator

Text Display Template

11 NC Integer Number of associated

(child) Connect Point

entities

12 CPTR1 Pointer Pointer to the directory

# • # entry for associated

• • • Connect Point 1

NC+11 CPTRNC Pointer Pointer to the directory

entry for associated

Connect Point NC

Additional Pointers as required (see 2. 2. 4. 4. 2)

404
310 - TEXT FONT DEFINITION

4.3.10 Text Font Definition Entity.

This entity defines the appearance of characters in a text font. The

data describing the appearance of a character may be located by the

Font Code (FC) and the ASCII character code. This entity may describe

any or all the characters in a character set. Thus, this entity may be

used to describe a complete font or a modification to a subset of

characters in another font. Font Number and Font Name are the

number and name used to reference the font on the originating system.

When this entity is a modification to another font, the Supersedes Font

value (Parameter 3) indicates which font the entity modifies. This

value is an integer which indicates the font number to be modified or the negative of the pointer value to the directory entry of another text

font definition entity. When this entity modifies another font, i.e., Parameter 3 references another font, the definitions in this entity

supersede the definition in the original font. For example, a complete

set of characters may have their font definition specified by this entity.

Another text font definition entity could reference the first definition

and modify a subset of the characters.

Each character is defined by overlaying an equally spaced square grid over the character. The character is decomposed into straight line

segments which connect grid points. Grid points are referenced by

standard Cartesian coordinates. The position of the character relative

to the grid is defined by two points. The character's origin point is placed at the origin (0,0) of the grid and defines the position of the

character relative to the text origin of that character. The second

point defines the origin point of the character following the character

being defined. This allows the spacing between characters to be

specified. Construction of text strings consists of placing the character

origin of the first character at the text string origin and placing

subsequent character origins at the location specified in the previous

character as the location of the next character's origin.

405
310 - TEXT FONT DEFINITION

The parameterization of the character appearance is described by the

motion of an imaginary pen moving between grid points. Commands to move the pen reference the grid location to which the pen is to move. The pen may be "lifted" such that its movement is not displayed. The

representation of the movement of the pen is a sequence of pen

commands and grid locations. Each movement of the pen is represented

by a pen updown flag and a pair of integer grid coordinates. The pen

up/down flag defaults to pen down. A flag value of 1 means the pen is to be lifted (i.e., display off) and moved to the next location in the

sequence. Upon arrival at this location the pen is returned to a "down"

position (i.e., display on)

The grid size is related to the text height through the scale parameter.

This parameter defines how many grid units equal one text height unit.

4.3.10.1 Directory Data

ENTITY TYPE NUMBER : 310

4.3.10.2 Parameter Data

Index Name TyPe Description

1 FC Integer Font Number

2 FNAME String Font Name

3 SF Integer Number of the font which

this definition supersedes

4 SCALE Integer Number of grid units which

equal one text height unit

5 N Integer Number of characters in this definition

6 AC 1 Integer ASCII code for first character

7 NX 1 Integer Grid location of the next

character's origin

406
310 - TEXT FONT DEFINITION

Index Name Type Description

8 NY 1 Integer

9 NM1 Integer Number of pen motions for

first character

10 PF

1 x Integer Pen up flag

0 = Down, 1 = Up

11 xl

i Integer Grid location to which the

pen is to move

12 Y1

i Integer

# #

9+NMl*3 AC2 Integer ASCII code for second

character

10+NM1*3 NX2 Integer Grid location of the next

character origin

1 1+NM1*3 NY2 Integer ft

12+NM1*3 NM2 Integer Number of pen motions fi second character

N

5+4N X

i=l

3*NMi Integer Last grid location of last character

Additional Pointers as required (see 2.2AA.2).

407
310 - TEXT FONT DEFINITION

An example of this entity using the character in Figure 4-41 is

FC

FNAME

SF

SCALE

N

AC1

NX1

NY 1 NM1

PF1

XI

Y

1

PF2

X2

Y2

PF3

X3

Y3

PF4

X4

Y4

18H STANDARD

8

60

65

11 0

4

0

4

8

0

8

0

1

2

4

0

6

4

In the parameter section of the IGES file it would look like: 1,8HSTANDARD,,8,60,65,1 1,0, 4,, 4, 8,, 8,0,1, 2, 4, ,6, 4....

Figure 4-42 provides another example.

408
310 TEXT FONT DEFINITION

FIGURE 4-41 EXAMPLE OF A CHARACTER DEFINITION

409
310 - TEXT FONT DEFINITION

r* 4 4 4 4 4 4 4 4 4 4 4 4 4

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

4 4 4 4 4 4 I- 4 4 4 4 4 4 4 4 4

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

4 4 4 4 4 4 4 4 44 4 4 4 4 4 4 4

SCALE

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

4 4 4 4 4 4 4 4 <4 4 4 4 4 4 4 4

(3.2) (5.2)

4 4 4 4 4 4 —4 4 4 4 4 4 4 4

4 4 4 4 4 4 « 4 4 4 4 4 4 4 4

(9,0)

4 4-3U 1 1 4 4 —4 (5,0) 4 4 4 (7) 4 4 4

GRID (3,0) ORIGIN OF

ORIGIN NEXT CHARACTER

4 4 4 4 4 4 4 4 '(5. •ih 4 4 4 4 4 4

4 4 4 4 4 4 4 -/ 4 4 4 4 4 4 4 4

(3,-2) (4.-2)

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

4 4 4 4 4 4 4 4 4 4 4 4 4 4 4 4

FIGURE 4-42 SECOND CHARACTER DEFINITION EXAMPLE

410
410 - VIEW

4.3.11 View Entity.

The View Entity defines a framework for specifying a viewing

orientation of an object in three dimensional model space (X,Y,Z). The

framework is also used to support the projection of all or part of model

space onto a view plane. One type of projection, an orthographic

parallel projection, can be specified.

4.3.11.1 Orthographic Parallel Projection. An orthographic parallel projection

onto a view plane of an object in model space is formed by passing rays

normal to the view plane through each point of the object and finding

the intersection with the view plane as shown in Figure 4-43.

TV

Figure 4-43 Orthographic Parallel Projection Figure 4-44 View Origin

4.3.11.2 View Coordinate System. The view plane can be described by

introducing a right-handed view coordinate system, (XV, YV, ZV) into

model space. The view plane is. the XV, YV plane, i.e., the plane ZV=0.

The view direction is along the positive ZV axis toward the view plane,

i.e., in the direction of the vector (0,0,- 1). The positive YV axis points

in the "up" direction in the resulting view. The point (0,0,0) in the view

coordinate system as shown in Figure 4-44 is called the view origin.

Thus a complete viewing orientation is specified by a view coordinate

system.

4.3.11.3 View Coordinates Obtained from Model Coordinates. View coordinates

are obtained from model coordinates through translation and rotation.

There are several ways that systems use to specify the data required to transfer from model to view coordinates. However, in each case, the

data can be recorded using Form 0 of the Transformation Matrix entity

such that the model coordinates are taken as input and the view

coordinates are produced as output, as follows, where R denotes the

rotation matrix and T the translation vector (see 3.14).

411
410 - VIEW

—

1

X<

1 » « V

YV = R Y + T

- ZV . .Z.

In this situation, R is called the view matrix.

The View entity specifies the view matrix and the translation vector by

use of a pointer to a Transformation Matrix entity in field 7 of the

Directory Entry. In the special case when the view matrix is the

identity matrix and there is zero translation, a zero value in field 7 may

be used.

Example 1 : (View coordinates obtained from model coordinates by a translation and then a rotation.)

The system defines a viewing orientation by specifying a view origin

(XO, YO, ZO) in model space and a rotation matrix so that

-j X< 1 3x3 rotation

YV = Matrix

.ZV. » —

1 X<i 3x3 rotation V 3x3 rotation

1 X0

1

YV = Matrix Y - Matrix YO

.ZV. _z. .zo.

Therefore, the rotation matrix is the view matrix, and in the

Transformation Matrix entity,

3x3 rotation

- h

3x3 rotation 'xo‘

, T= - YO

Matrix Matrix .zo.

412
410 - VIEW

Example 2: (View coordinates obtained from model coordinates by a

rotation and then a translation.)

The system defines a viewing orientation by specifying a rotation

matrix and a translate or pan vector (XL, YL, ZL) expressed in the

rotated coordinate system, so that

1X<1

? 3x3 rotation *x'

i

Xr __j YV = Matrix Y - YL

.zv. . z

.

. ZL.

Therefore, the rotation matrix is the view matrix, and in the Transformation Matrix entity,

3x3 rotation 1 X_) R = Matrix , T = - YL

1 N i—

4.3.11.4 Simple Form of the View Entity. The View entity provides a view

number for the purpose of identifying differing view orientations.

However, no standard indexing scheme is presumed to exist.

In its simplest form, the View entity consists of a pointer to the

Transformation Matrix entity (in field 7 or the Directory Entry), and a view number. The Transformation Matrix entity specifies a view matrix

R and a translation vector T as given in the preceeding section.

4.3.11.5 Projection of a View Volume. In some cases, a view volume and a scale

factor may be required to control the projection of the view into a two

dimensional drawing space specified by a Drawing entity (see 4.3.4).

The view volume bounds that portion of the data which will be

projected after clipping is performed. The view volume is a rectangular

parallelepiped with limits specified by Plane entities defined in the

model coordinate system. The absence of a clipping in a particular

direction may be included by setting the pointer for the appropriate

Plane entity equal to zero.

413
410 VIEW

The Plane entities used to define the view volume shall not be artibrary

planar definitions. After transformation from model coordinates to view coordinates each plane must result in a plane perpendicular to the

appropriate view coordinate system axis (e.g., the left side of the view

volume must transform into a plane XV=constant). In addition, only the

coefficients of the Plane entity are required, i.e., the bounding curve

and display symbol are not used. See Figure 4-45.

FIGURE 4-45 VIEW VOLUME

4.3.11.6 Projection Operations. The order of operations for the view entity is as

follows:

1. Transform from model to view space.

2. Perform clipping (if included).

3. Perform projection onto the view plane.

4. Transform from view space to drawing space.

The projection onto the view plane and the transform from view space

to drawing space can be controlled by the following equation in the case

of orthographic parallel projection, where S is the scale factor and

XORIGIN and YORIGIN are defined in the Drawing Entity (see 4.3.4).

r Xat

s o o XV

* • XORIGIN

YD

> m o s o

1

>>

>~N1

+ YORIGIN

414
410 - VIEW

4.3.11.7 Entity Display. The display of an entity in a particular view is controlled by

the use of the view value in field 6 of the Directory Entry for the entity. If

this value is zero or undefined, the entity is displayed with its own

characteristics in all views unless display is controlled by other parameters

(e.g., pointed to by another entity such as Subfigure Definition or Drawing).

If this value is a pointer to a View entity, the entity is displayed with its own

characteristics in only the one view.

The selection of multiple views and/or display characteristics for an entity

may be made by using one of the Views Visible associativity entities (type

number 402, form 3 or 4). The view value for the entity then is a pointer to

this associativity instead of to a View entity.

4.3.11.8 Directory Data

ENTITY TYPE NUMBER: 410

4.3.11.9 Parameter Data

Index Name Jype Description

1 VNO Integer View number

2 SCALE Real Scale factor

(Default = 1.0)

3 XVMINP Pointer Pointer to left side of view

volume (XVMIN

plane) or zero

4 YVMAXP Pointer Pointer to top of

view volume

(YVMAX plane) or zero

5 XVMAXP Pointer Pointer to right

side of view

volume (XVMAX

plane) or zero

6 YVMINP Pointer Pointer to bottom

of view volume

(YVMIN plane) or zero

415
410 - VIEW

7 ZVMINP Pointer Pointer to back of

view volume

(ZVMIN plane) or zero

8 ZVMAXP Pointer Pointer to front

of view volume

(ZVMAX plane) or zero

Additional Pointers as required (see 2. 2.4. 4.2)

416
416 - EXTERNAL REFERENCE

4.3.12 External Reference Entity

The External Reference Entity provides a link between an entity in a referencing file and the definition or a logically related entity in referenced file. Further, in keeping with the concept of treating this

entity as the definition which it replaces the subordinate entity switch

should be set as it would be on the definition replaced. See section 2.5.4

for the entities used in the linkage.

Three forms of the External Reference Entity are defined. Two of these

forms are used to reference a definition and one form is a logical

reference. Form 0 is used when a single definition from the referenced file

is desired. This would be the case where the referenced file contained a

collection of definitions. Form 1 is used when the entire file is to be

instanced. This would be the case where the referenced file contained a complete sub-assembly. Form 2 is used for external logical references

where an entity in one file relates to an entity in a separate file (e.g., when

each sheet of a drawing is a separate file, and a flange on one sheet is also

depicted on, or mates with, a flange on another sheet). Forms 0 and 2 require an entity-unique symbolic name. The following entities and the

parameter which supplies the symbolic name are identified for use:

Parameter

Entity Name Index Description

132 Connect Point 9 CP Function Name (unique)

302 Associativity Definition () Implementor assigned

304 Line Font Definition () Implementor assigned

306 MACRO Definition 2 Entity Type Identification

308 Subfigure Definition 2 Subfigure name (unique)

310 Text Font Definition 2 Font name

312 Text Display Template () Implementor assigned

314 Color Definition () Implementor assigned

320 Network Subfigure 2 Subfigure name (unique)

Definition

417
416 EXTERNAL REFERENCE

Possible alternatives for the entity-unique symbolic name for those entities

marked "Implementor assigned" could be: (1) the property REFERENCE

DESIGNATOR (Type 406, Form 7), or (2) the ENTITY LABEL, ENTITY

SUBSCRIPT (directory entry fields 18 and 19.)

4.3.12.1 Directory Data

ENTITY TYPE NUMBER: 416

4.3.12.2 Parameter Data (Form 0 and 2)

Index

1

2

Name Type

EXTFID String

EXTNAM String

Description

External Reference File

Identifier (contained

as Global Parameter

Number 4 in the referenced

file)

External Reference Entity

Symbolic Name

Additional Pointers as required (see 2. 2. 4. 4. 2)

4.3.12.3 Parameter Data (Form 1)

Index

1

Name TyPe Description

EXTFID String External Reference File

Identifier (contained

as Global Parameter

Number 4 in the referenced

file)

Additional Pointers as required (see 2. 2. 4. 4. 2)

418
418 - NODAL LOAD/CONSTRAINT

4.3.13 Nodal Load/Constraint Entity

This entity relates loads and/or constraints to specific nodes in the

Finite Element Model. This is accomplished by creating a relation

between node entities and the tabular data property that contains the

load or constraint data. Each load and constraint case will require a nodal load/ constraint entity and a tabular data property Form 11 with

PTYPE=12.

Figure 4-45 shows the relationship or linkage between the nodal

load/constraint entity and the tabular data which carries the load or constraint vector. The relationship or linkage is also shown on the

general note entity which described the load/ constraint test case being

performed. There is a one to one correspondence between the load case

description and the general note entity and the pointer to the tabular

data containing the load case magnitudes (see also section 2.5.6).

PROPERTY

POINTERS

FIGURE 4-46 NODAL LOAD / CONSTRAINT

419
418 - NODAL LOAD/CONSTRAINT

4.3.13.1 Directory Data

ENTITY TYPE NUMBER: 418

4.3.13.2 Parameter Data

Index Name TyPe Description

1 NC Integer Total number of cases

2 TYPE Integer 1 = Loads

2 = Constraints

3 DE Pointer Node Pointer

4 PTR

1

Pointer Pointer to definition of each load case stored in general note entity

NC+3 PTRNC

•

Pointer

*

Additional Pointers as required (see 2. 2. 4. 4. 2).

420
314 - COLOR DEFINITION

4.3.14 Color Definition Entity

The Color Definition Entity is used to communicate the relationship of

the primary (red, green, and blue) colors to the intensity level of the

respective graphics devices as a percent of the full intensity range.

These red, green, blue coordinates (RGB) can be readily transformed to cyan, magenta, yellow (CMY) and to hue, lightness, saturation (HLS)

using transformations that are given in Appendix F.

4.3.14.1 Directory Data

ENTITY TYPE NUMBER: 314

4.3.14.2 Parameter Data

Index Name Type

1 CC1 Real

2 CC2 Real

3 CC3 Real

4 CNAME String

Description

First color coordinate (red) as a percent of full intensity (range 0. to 100.)

Second color coordinate (green) as a percent of full intensity (range 0. to 100.)

Third color coordinate (blue) as a percent of full intensity (range 0. to 100.)

Color name; this is an optional

character string which may contain some verbal description of the

color. If the color name is not

provided and additional pointers are required, a placekeeper must

be supplied between CC3 and the

first additional pointer.

Additional pointers as required (see 2. 2. 4. 4. 2).

421
312 - TEXT

4.3.15

4.3.15.1

4.3.15.2

4.3.15.3

DISPLAY TEMPLATE

Text Display Template Entity

The Text Display Template Entity is used to display self-contained

information such as numbers and/or text strings according to the template's

display parameters. There are two forms of the Text Display Template;

Absolute and Incremental.

Note: For a more detailed description of the parameters, see the General

Note Entity (type 212)

Absolute Text Display Template (Form 0)

This form of the Text Display Template specifies the parameters for the text block at the specified starting point. The text to be displayed are taken from

the entity pointing to this instance of the Text Display Template. If the text

string to be displayed is not explicitly pointed to then the first text string

specified in the pointing entity will be displayed.

Directory Data

ENTITY TYPE NUMBER: 312

FORM NUMBER: 0

Parameter Data

Index Name TyPe Description

1 CBW Real Character box width

2 CBH Real Character box height

3 FC Integer or Pointer

Font characteristic (or pointer if negative) (Default = 1)

4 SL Real Slant angle (Radians) (Default

Pi/ 2)

5 A Real Rotation angle (Radians)

422
312 - TEXT DISPLAY TEMPLATE

4.3.15.4

4.3.15.5

4.3.15.6

6 M Integer Mirror Flag

7 VH Integer Rotate internal text flag

8 XS Real

coordinates of lower left 9 YS Real corner of first character

box; see form for

10 zs Real coordinate type

Additional pointers as required (see paragraph 2. 2. 4.4. 2).

Incremental Text Display Template (Form 1)

This form of the Text Display Template specifies the parameters for the text

block at a starting point specified incrementally from one taken from the

entity point to the given instance of the Text Display Template. The text to be displayed is taken from the entity pointing to this instance of the Text

Display Template. If the text string to be displayed is not explicitly pointed

to, then the first string specified in the pointing entity will be displayed.

Directory Data

ENTITY TYPE NUMBER: 312

FORM NUMBER: 1

Parameter Data

Index Name Type Description

1 CBW Real Character box width

2 CBH Real Character box height

3 FC Integer or Font characteristic (or pointer if Pointer negative) (Default = 1).

4 SL Real Slant angle (Radians) (Default =

pi/ 2)

5 A Real Rotation angle (Radians)

6 M Integer Mirror Flag

7 VH Integer Rotate internal text flag

8 DXS Real Increment in X from X coordinate

found in parent entity

423
312 - TEXT DISPLAY TEMPLATE

9 DYS Real Increment in Y from Y

found in parent entity

coordinate

10 DZS Real Increment in Z from Z

found in parent entity

coordinate

Additional pointers as required (see 2. 2. 4. 4. 2).

424
APPENDIX A PART FILE EXAMPLES

APPENDIX A

PART FILE EXAMPLES

This appendix contains three sample parts encoded in the Specification ASCII format.

These files are included herein to provide a guide to the usage of IGES and, as such, do not

represent all design application uses. The files are a two-dimensional application using

structure entities, a three-dimensional mechanical part with dimensioning, and a threedimensional part with 2-D drawing views defined.

Example file 1 is an integrated circuit (IC) cell. The IC application was selected because

of the predominance of 2-D geometry used in electrical designs. The geometry used in the cell in Figure A-l consists of simple closed area, linear path entities and line widening

property. The structure entities are nested subfigures using a network subfigure

definition, array subfigure instance. A connect point is included to identify the signal

port. The geometry is on five different levels, each representing a process mask. The

entity label field of each directory entry record has optional text included to describe the

entity’s use. The entities in this file would be typical of those used in an IC application to transfer either cell libraries or a complete design between design systems. The file of a

design prepared for pattern generation, with subfigures resolved and the geometry

fractured, would use the flash entity exclusively. The cell file was adapted from a cell

library in A Guide to LSI Implementation with kind permission from author Carlos Sequin.

Example file 2 is a three-dimensional mechanical part containing geometry entities and

annotation entities typically found on engineering drawings. Included as geometry are

points, lines, circular arcs and conics. For annotation the file includes linear dimensions,

angular dimensions, radius dimensions, ordinate dimensions, a general label and general

notes. Figure A-2 shows the mechanical part which was used during one of the early

public demonstrations of intersystem data exchange.

Example file 3 is included to show the use of view entities and drawing entities in conjunction with a three-dimensional part model to convey a drawing to the receiving

system. Figure A-3 shows the example drawing. In this way model geometry and viewing

parameters are logically separate. A 3-D model as well as the drawing is received

enabling additional views to be created if necessary, and changes to the part model are

reflected in all views.

423
APPENDIX A.- PART FILE EXAMPLES

FIGURE A - 1 ELECTRICAL PART EXAMPLE

426
APPENDIX A - PART FILE EXAMPLES

EXAMPLE 1 ELECTRICAL PART

INTEGRATED CIRCUIT SEMICUSTOM CELL (ONE PART OF A LIBRARY FILE) S 1H, , 1H; , 10H5MICRONLIB , 5HPADIN, 9HEXAMPLE 1 ,4HIGES, 16 ,38,06 ,38,13 , G

10HIC. LIBRARY ,1.0,9 ,2 HUM, 1 , , 13 H851128. 090000 ,0 .01 ,265.0 ,9HC. H. PARKS, G

23HGENERAL DYNAMICS/POMONA, 4 , 0; G

308 01 1 0 0 00020201D

308 0 1 SUBFIG1 D

106 02 1 1 0 00020200D

106 0 4 1 63 VDDPORT D

106 03 1 1 0 00020200D

106 0 4 1 63 GNDPORT D

106 04 1 1 0 00020200D

106 0 4 1 63 BONDPAD D

106 05 1 7 0 00020200D

106 0 5 1 63 GLASSBOX D

320 06 1 0 0 00010201D

320 0 1 CELLFIG D

408 07 1 0 0 00030200D

408 0 1 INST1 D

106 08 1 3 0 00020200D

106 0 3 2 63 ACTBOX D

106 10 1 3 0 00020200D

106 0 3 1 63 ACTBOX D

106 11 1 3 0 00020200D

106 0 3 1 11 ACTSTG D

106 12 1 3 0 00020200D

106 0 3 2 63 ACTBOX D

132 14 1 3 0 00020400D

132 0 1 SIGPORT D 106 15 1 6 0 0002020 0D

106 0 8 2 63 CUT D

106 17 1 6 0 0002020 0D

106 0 8 2 63 CUT D

308 19 1 0 0 00020201D

308 0 1 SUBFIG2 D

106 20 1 6 0 01030200D

106 0 8 1 63 CUTDEF D

412 21 1 0 0 00030201D

412 0 1 CUTARR D

106 22 1 2 0 00020200D

106 0 2 2 11 GATESTG D

106 24 1 2 0 0002020 OD 106 0 2 2 63 GATEBOX D 106 26 1 1 0 00020200D

106 0 4 1 63 GATEBOX D

406 27 1 0 0 0001 0200D

406 0 1 5 LINWIDTH D 308,0 , 6HPADBLK, 4,03,05,07,09; 01P

106 ,1,5,0.,0.,0.,265. , 0 .

, 26 5 . ,-20. ,0 . ,-20. ,0 . ,0 .; 03P

106 ,1 ,5,0., 30. ,-245. ,245. ,-245. ,245. ,-26 5. ,3 0. ,-26 5. ,30. ,-245. ; 05P

106 ,1,5,0., 6 5. ,-65. ,200 . ,-65. ,200 . ,-200 . ,65. ,-200., 6 5. ,-65. ; 07P

106 ,1,5,0. ,75. ,-75. ,190. ,-75. ,190. ,-190. ,7 5. ,-190. ,7 5. ,-75.; 09P

320,1 ,5HPADIN,12 ,13,15,17 ,19,21 ,23 ,25 ,27 ,33 ,35,37 ,39; IIP

408.01.0.

.0..0,; 13P

106 ,1,5,0., 30., -210., 222. 5, -210., 222. 5, -255., 3 0., -255. ,30., 15P

-210.; 15P

106.

1.5.0.

. 65., -25. ,75. ,-25. ,7 5. ,-45. ,6 5. ,-45. ,6 5. ,-25.; 17P

106.

1.3.0.

. 77. 5, -27. 5, 240. ,-27. 5, 240., -26 2. 5, 0,1, 41; 19P

106 , 1,5,0., 222. 5, -21 5. , 237 . 5 ,-21 5 . , 237 . 5 ,-247 . 5 , 222 . 5 ,-247 . 5 , 21P

222.5,-215.; 21P

132.

240.,

-26 5., 0.,, 2,1,,,,, 01, 2, 1,11; 23P

112

3 01

02

03

04

05

06

07

08

09

10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

41

42

01

02

03

04

05

06

07

08

09

10

11

12

13

14

427
APPENDIX A - PART FILE EXAMPLES

106

.1.5.0.

. 67. 5, -32. 5, 72. 5, -32. 5, 72. 5, -42. 5, 67. 5, -42. 5, 67. 5, 25P

-32.5; 25P 106.1.5.0.

.227.5,-252.5,232.5,-252.5,232.5,-257.5,227.5,-257.5, 27P

227.5,

-252.5; 27P

308.

0.

7,CONTACT, 1,31; 29P

106.

1.5.0.

, -5. ,2. 5, 5. ,2. 5, 5. ,-2.5, -5. ,-2.5, -5. ,2. 5; 3 IP 412.29.1

.0.

37.5,-250. ,0., 8,1 ,25 . , 0 . , 0 . , 0; 33P

106.1.6.0.

.232.5,-212.5,232.5,-222.5,50. ,-222.5,50. ,-240. , 35P

232.5,

-240. ,232.5,-247.5,0,1,41; 35P

106.

1.5.0.

. 225., -250., 23 5., -250., 23 5., -260., 225. ,-260., 225., 37P

-250.; 37P

106.

1.5.0.

.65. ,-30. ,75. ,-30. ,75. ,-65. ,65., -6 5., 65. ,-30.; 39P

406.5.5.0.

1.1.0.0, 41P

S 1G 3D 42P 27 T

15

16

17

18

19

20

21

22

23

24

25

26

27

1

428
APPENDIX A - PART FILE EXAMPLES

<

2T3

o

<1

-

2.0

1.0

DATUM B

FIGURE A - 2 MECHANICAL PART EXAMPLE
APPENDIX A - PART FILE EXAMPLES

EXAMPLE 2 MECHANICAL PART

THIS IS A SAMPLE PART FOR USE IN 1THE AOTOFACT 82 IGES DEMONSTRATION S

, , 8HPANEL123 ,10HPANEL. IGES , 4 HEX 2 ,4HIGES, 16,38,7, 38,14,8HPANEL123 ,1.0, G

1 , 4HINCH ,1,0 .028,,13H850816 .144004 ,0.0005, 100.0 ,9HD. BRIGGS, 6HBOEING, 4 , 0;G

124 1 1 1 0 0 0 0 OD

124 0 0 1 0 OD

212 2 1 1 5 0 1 0 10100D

212 0 0 3 0 OD 214 5 1 1 5 0 1 0 10100D

214 0 0 1 2 OD

210 6 1 1 5 0 1 0 100D

210 0 0 1 0 OD 110 7 1 1 1 0 0 0 OD

110 0 0 1 0 OD 110 8 1 1 1 0 0 0 OD 110 0 0 1 0 OD 110 9 1 1 1 0 0 0 OD 110 0 0 1 0 OD 110 10 1 1 1 0 0 0 OD 110 0 0 1 0 OD 100 11 1 1 1 0 1 0 OD 100 0 0 1 0 OD 100 12 1 1 1 0 1 0 OD

100 0 0 1 0 OD

100 13 1 1 1 0 1 0 OD 100 0 0 1 0 OD 100 14 1 1 1 0 1 0 OD 100 0 0 1 0 OD 116 15 1 1 2 0 0 0 OD 116 0 0 1 0 OD 116 16 1 1 2 0 0 0 OD 116 0 0 1 0 OD 116 17 1 1 2 0 0 0 OD 116 0 0 1 0 OD

116 18 1 1 2 0 0 0 OD

116 0 0 1 0 OD 104 19 1 1 3 0 1 0 OD 104 0 0 2 1 OD

116 21 1 1 2 0 0 0 OD

116 0 0 1 0 OD 116 22 1 1 2 0 0 0 OD 116 0 0 1 0 OD 212 23 1 1 4 0 1 0 10100D

212 0 0 1 0 OD 214 24 1 1 4 0 1 0 10100D

214 0 0 1 2 OD

214 25 1 1 4 0 1 0 10100D

214 0 0 1 2 OD

106 26 1 1 4 0 1 0 10100D

106 0 0 1 40 OD 106 27 1 1 4 0 1 0 10100D

106 0 0 1 40 OD

216 28 1 1 4 0 1 0 100D

216 0 0 1 0 OD 212 29 1 1 4 0 1 0 10100D

212 0 0 1 0 OD 214 30 1 1 4 0 1 0 10100D

214 0 0 1 2 OD

214 31 1 1 4 0 1 0 10100D

214 0 0 1 2 OD

106 32 1 1 4 0 1 0 10100D

11

21

2

3

45

67

89 10

II12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

4142

43

44

45

46

47

48

49

50

5152

53

54

55

56

57

430
106

106

106

216

216

212

212

106

106

218

218

212

212

106

106

218

218

212

212

106

106

218

218

212

212

106

106

218

218

212

212

106

106

218

218

212

212

106

106

218

218

212

212

106

106

218

218

212

212

106

106

218

218

212

212

214

214

222

222

212

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

97

98

99

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

APPENDIX

A PART FILE 0 0 1 40 0D

33 1 1 4 0 1 0 10100D 0 0 1 40 OD

34 1 1 4 0 1 0 100D 0 0 1 0 OD 35 1 1 5 0 1 0 101 OOD 0 0 1 0 OD

36 1 1 5 0 1 0 10100D 0 0 1 40 OD

37 1 1 5 0 1 0 100D 0 0 1 0 OD 38 1 1 5 0 1 0 10100D 0 0 1 0 OD 39 1 1 5 0 1 0 10100D 0 0 1 40 OD 40 1 1 5 0 1 0 100D 0 0 1 0 OD

41 1 1 5 0 1 0 10100D 0 0 1 0 OD

42 1 1 5 0 1 0 10100D 0 0 1 40 OD

43 1 1 5 0 1 0 100D 0 0 1 0 OD 44 1 1 5 0 1 0 10100D 0 0 1 0 OD 45 1 1 5 0 1 0 1010 OD 0 0 1 40 OD

46 1 1 5 0 1 0 100D 0 0 1 0 OD 47 1 1 5 0 1 0 101 OOD 0 0 1 0 OD

48 1 1 5 0 1 0 10100D 0 0 1 40 OD

49 1 1 5 0 1 0 100D 0 0 1 0 OD

50 1 1 5 0 1 0 10100D 0 0 1 0 OD

51 1 1 5 0 1 0 101 OOD 0 0 1 40 OD

52 1 1 5 0 1 0 100D 0 0 1 0 OD

53 1 1 5 0 1 0 101 OOD 0 0 2 0 OD 55 1 1 5 0 1 0 10100D 0 0 1 40 OD

56 1 1 5 0 1 0 100D 0 0 1 0 OD 57 1 1 5 0 1 0 101 OOD 0 0 2 0 OD

59 1 1 5 0 1 0 10100D 0 0 1 40 OD

60 1 1 5 0 1 0 100D 0 0 1 0 OD 61 1 1 5 0 1 0 101 OOD 0 0 2 0 OD 63 1 1 5 0 1 0 101 OOD 0 0 1 2 OD

64 1 1 5 0 1 0 100D 0 0 1 0 OD 65 1 1 6 0 1 0 101 OOD

431
212

214

214

214

214

106

106

106

106

216

216

212

212

214

214

214

214

106

106

106

106

216

216

212

212

214

214

214

214

106

106

106

106

216

216

212

212

214

214

214

214

106

106

106

106

216

216

110

110

110

110

212

212

214

214

214

214

106

106

106

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

A - PART FILE EXAMPLES 0 0 1 0 0D

66 1 1 6 0 1 0 10100D 0 0 1 2 OD

67 1 1 6 0 1 0 10100D 0 0 1 2 OD

68 1 1 6 0 1 0 1010100D 0 0 1 40 OD

69 1 1 6 0 1 0 10100D 0 0 1 40 OD

70 1 1 6 0 1 0 100D 0 0 1 0 OD

71 1 1 6 0 1 0 10100D 0 0 1 0 OD

72 1 1 6 0 1 0 101 OOD 0 0 1 2 OD

73 1 1 6 0 1 0 101 OOD 0 0 1 2 OD

74 1 1 6 0 1 0 10100D 0 0 1 40 OD

75 1 1 6 0 1 0 1010100D 0 0 1 40 OD

76 1 1 6 0 1 0 100D 0 0 1 0 OD 77 1 1 6 0 1 0 101 OOD 0 0 1 0 OD

78 1 1 6 0 1 0 10100D 0 0 1 2 OD 79 1 1 6 0 1 0 10100D 0 0 1 2 OD

80 1 1 6 0 1 0 101 OOD 0 0 1 40 OD

81 1 1 6 0 1 0 101 OOD 0 0 1 40 OD

82 1 1 6 0 1 0 100D 0 0 1 0 OD

83 1 1 6 0 1 0 10100D 0 0 1 0 OD 84 1 1 6 0 1 0 10100D 0 0 1 2 OD

85 1 1 6 0 1 0 10100D 0 0 1 2 OD

86 1 1 6 0 1 0 10100D 0 0 1 40 OD

87 1 1 6 0 1 0 101 OOD 0 0 1 40 OD

88 1 1 6 0 1 0 100D 0 0 1 0 OD

89 1 4 6 0 0 0 100D 0 0 1 0 OD

90 1 4 6 0 0 0 100D 0 0 1 0 OD

91 1 1 6 0 1 0 101 OOD 0 0 1 0 OD

92 1 1 6 0 1 0 10100D 0 0 1 2 OD

93 1 1 6 0 1 0 10100D 0 0 1 2 OD 94 1 1 6 0 1 0 1010100D 0 0 1 40 OD

95 1 1 6 0 1 0 1010100D

432
APPENDIX A - PART FILE EXAMPLES

106 0 0 1 40

202 96 1 1 6 0 1 0 124.1.000. 202 0 0 1 0 0.0.0.0.0.0.0.0.1.000.0.0.0.0.0.0.0.0.1.000.0.0.0.0;

212. 2. 10.

0.

98. 0.10. 1.1. 57 1.0. 0.0. 0.3. 210. 1.6 56. 0.0.10HDRILL .010

,10,1 .02,0.100,1 ,1 .571,0.0,0,0,3 .210,1 .506 ,0 .0,10H(6 PLACES) ,0,

0;21 4. 2.

0.

1 50. 0. 050. 0. 0. 4. 800 .2. 000. 4. 562 ;l. 546 ,4. 26 2 ,1.546 ,0,0; 210.3.1.5.0.

0;

110.0.

0.0.200.0.0.0.0.3.000.0.0.0.0;

110.0.

200.0.0.0.0.4.800.0.0.0.0.0.0;

110.5.000.

0.200.0.0.5.000.3.000.0.0.0.0;

110.0.

200.3.200.0.0.4.800.3.200.0.0.0.0;

100.0.

0.4.800.3.000.5.000.3 .000,4.800,3.200,0 ,0;

100.0.

0.0.200.3.000.0.200 .3.200.0.0.3.000.0.0;

100.0.

0.0.200.0.200.0.0.0.200.0.200.0.00.0.0;

100.0.

0.4.800.0.200.4.800.0.0.5.000.0.200.0.0;

116 ,4.000,3.000,0.0,0,0,0;

116.3.000.

3.000.0.0.0.0.0;

116.2.000.

3.000.0.0.0.0.0;

116.1.000.

3.000.0.0.0.0.0;

104.10.000,

-12.000,10.000,-8.000,-8.000,7.000,0.0,1.3538,1.3538,

1.3538.1.3538.0.

0; 116.4.800.1.000.

0.0.0.0.0;

116.4.800.2.000.

0.0.0.0.0;

212.1.3.0.

421.0.156.1.1 .57 1.0. 0.0. 0,-0. 639, 1. 614, 0.0, 3H3. 2, 0,0;

214.1.0.

150.0.050.0.0,-0.454,3.200,-0.454,1.870,0,0;

214.1.0.

150.0.050.0.0,-0.454,0.0,-0.454,1.514,0,0;

106.1.3.0.

0.0.0.3.200,-0.094,3.200,-0.579,3.200,0,0;

106.1.3.0.

0.0.0.0.0,-0.094,0.0,-0.579,0.0,0,0;

216.39.41.43.45.47.0.

0;

212.1.3.0.

437.0.156.1.1.571.0.0.0.0.2.032,-0.447,0.0,3H5.0,0,0;

214.1.0.

150.0.050.0.0.0.0,-0.369,1.932,-0.369,0,0;

214.1.0.

150.0.050.0.0.5.000,-0.369,2.519,-0.369,0,0;

106.1.3.0.

0.0.0.0.0.0.0,-0.094,0.0,-0.494,0,0;

106.1.3.0.

0.5.000.0.0.5.000,-0.094,5.000,-0.494,0,0;

216.51.53.55.57.59.0.

0; 21 2. 1.3.

0.

374. 0.1 56. 1.1. 571. 1.57 1.0. 0.4. 07 8. 4. 181. 0.0. 3 HI. 0,0,0;

106.1.3.0.

0.4.000.3.094.4.000.3.188.4.000.3.993.0.0;

218.63.65.0.

0; 21 2. 1. 3.

0.

421. 0. 1 56. 1. 1. 57 1.1. 57 1. 0.0. 3. 07 8. 4. 183. 0.0. 3 H2. 0,0,0;

106.1.3.0.

0.3.000.3.094.3.000.3.188.3.000.3.996.0.0;

218.69.71.0.

0;

212.1.3.0.

437.0.156.1.1.571.1 .571.0.0.2.078.4.177.0.0.3H3.0,0,0;

106.1.3.0.

0.2.000.3.094.2.000.3.188.2.000.3.989.0.0;

218.75.77.0.

0; 21 2. 1. 3.

0.

437. 0. 1 56. 1. 1. 57 1. 1. 57 1. 0.0. 1.078. 4. 177. 0.0. 3 H4. 0,0,0;

106.1.3.0.

0.1.000.3.094.1.000.3.188.1.000.3.989.0.0;

218.81.83.0.

0; 212. 1.3.

0.

374. 0.1 56..1.1. 57 1.0. 0.0. 0.6. 211. 0.922. 0.0. 3 HI. 0,0,0;

106.1.3.0.

0.4.894.1.000.4.988.1.000.6.024.1.000.0.0;

218.87.89.0.

0; 212. 1. 3.

0.

421. 0. 1 56. 1. 1. 571. 0. 0. 0.0. 6. 211. 1.922. 0.0. 3 H2. 0,0,0;

106

.1.3.0.

0.4.894.2.000.4.988.2.000.6.024.2.000.0.0;

218.93.95.0.

0; 212.1.7.1

.248.0.

156.1.1 .571.0. .0.0.6.23 ,-0 .078,0 .0 ,7HDATUM B,0,

0;

1 06 .1.3.

0.

0. 5. 094. 0.0. 5. 188. 0.0. 6. 042. 0.0. 0.0;

218.99.101.0.

0; 212. 1. 7. 1. 232.

0.

1 56. 1.1. 57 1.1. 57 1.0. 0.5. 07 8. 4.1 93. 0..7HDATUM A,

OD 17 8 100D 179

OD 180

IP 1 3P 2 3P 3 3P 4 5P 5 7P 6 9P 7 IIP 8 13P 9 15P 10

17P 11

19P 12

21P 13

23P 14

25P 15

27P 16

29P 17

31P 18

33P 19

33P 20

35P 21

37P 22

39P 23

41P 24

43P 25

45P 26

47P 27

49P 28

51P 29

53P 30

55P 31

57P 32

59P 33

6 IP 34

63P 35

65P 36

67P 37

69P 38

7 IP 39

73P 40

75P 41

77P 42

79P 43

81P 44

83P 45

85P 46

87P 47

89P 48

91P 49

93P 50

95P 51

97P 52

99P 53

99P 54

101P 55

103P 56

105P 57

433
APPENDIX A - PART FILE EXAMPLES

0,0; 105P

106. 1.3.

0.

218.105.107.0. 0. 5. 000. 3. 094. 5. 000. 3. 187. 5.000. 4. 006. 0.0; 107P

0; 109P 212.2.4.0.

35.0.100.1.1 .571.0. .0.0. 4. 029. 2. 611.0.. 4H. 2 R, 5, 0.500, 111P

0.100,1,1.571,0.0,Q,0,4.029,2.461,0.0,5H(TYP) ,0,0; 11 IP 214.2.0.

150.0.050.0.0.4.877.3.185.4.862.2.511.4.562.2.511.0.0; 113P 222.111.113.4.800.3.000.

0.0; 115P

212. 1.3.

0.

240. 0.100. 1.1. 57 1.0. 0.0. 0.1. 559. 0.6 02. 0.0. 3 HI. 0,0,0; 117P

214.1.0.

150.0.050.0.0.1 .663.0.0.1.663.0.538.0.0; 119P

214.1.0.

150.0.050.0.0.1 .663.1 .000.1.663.0.766.0.0; 121P

106.1.3.0.

0.0.200.0.0.0.294.0.0.1.788.0.0.0.0; 123P

106.1.3.0.

216.117.119.121.123.125.0. 0.1.000.1.000.1.094.1.000.1.788.1.000.0.0; 125P

0; 127P

21 2. 1.3.

0.

2 40. 0.100. 1.1. 57 1.0. 0.0. 0.0. 53 7. 0.27 5. 0.0. 3 HI. 0,0,0; 129P

214.1

.0.

150.0 .050.0.0.1 .000.0.325.0 .809.0 .325.0.0; 131P

214.1

.0.

150.0 .050.0.0.0.0.0.325.0.473.0.325.0.0; 133P

106 ,1 ,3,0.0,1 .000,1 .000,1 .000,0.906,1.000,0.200,0,0; 13 5P

106.1.3.0.

0.0.0.0.012.0.0.0.106.0.0.0.200.0.0; 137P

216.129.131.133

.135.137.0.

0; 139P

212.1.3.0.

240.0.100.1.1 .571 . 0 . 0 .0 .0 . 0 .47 0 .1 .289 .0 . 0 .3H1 .0 ,0 , 0; 141P

214.1

.0.

150.0.050.0.0.0.971.1 .736.0.688.1.453.0.0; 143P

214.1.0.

150.0.050.0.0.0.264.1.029.0.459.1.225.0.0; 145P

106.1.3.0.

0.1 .354.1.354.1 .287.1 .420.0.882.1.825.0.0; 147P

106

.1.3.0.

0.0.646.0.646.0.580.0.713.0.175.1.118.0.0; 149P

216,141 ,143,145,147,149,0,0; 151P

212.1.2.0.

170.0.100.1.1.571.0.0.0.0.1.631.1.622.0.0.2H.5,0,0; 153P

214.1

.0.

150.0 .050.0.0 .1 .863.1.509.2.146.1 .226.0 .0; 155P

214.1.0.

150.0.050.0.0.1.509.1.863.1.226.2.146.0.0; 157P

106.1.3.0.

0.1.177.0.823.1.243.0.890.1.951.1.598.0.0; 159P

106.1.3.0.

0.0.823.1.177.0.890.1.243.1.598.1.951.0.0; 161P 216.153.155.157.159.161.0.

0; 163P

110.0.

500.0.500.0.0 ,1 .500,1 .500,0.0,0,0; 16 5P

110.1.225.0.

775.0.0.0.775.1.225.0.0.0.0; 167P

212.1.2.0.

220.0.100.1.1.571.0.0.0.0.2.566.0.786.0.0.2H45,0,0; 169P

214.1.0.

150.0.050.0.0.2.847.0.0.2.754.0.722.0.0; 171P

214.1.0.

150.0.050.0.0.2.013.2.013.2.683.0.951.0.0; 173P

106.1.3.0.

0.4.988.0.0.4.894.0.0.2.972.0.0.0.0; 17 5P

106.1.3.0.

0.2.000.2.000.2.066.2.066.2.101.2.101.0.0; 177P

202.169.175.177.0.

0.0.0.2.847.171.173.0.0; 17 9P

S 1G 2D 180P 96 T

58

59

60

61

62

63

64

65

66

67

68

69

70

71

72

73

74

75

76

77

78

79

80

81

82

83

84

85

86

87

88

89

90

91

92

93

94

95

96

1

434
APPENDIX A - PART FILE EXAMPLES

FIGURE A - 3 DRAWING AND VIEW EXAMPLE

435
APPENDIX A - PART FILE EXAMPLES

EXAMPLE 3 VIEW AND DRAWING PART

EXAMPLE OF MODEL WITH VIEW AND DRAWING ENTITIES

1H, f lH; ,19 BPROD ID FROM SENDER, II HMANUAL . IGS , 9HEXAMPLE 3,

4HIGES, 32,38,8,1 53, 15 , 20HPR0D ID FOR RECEIVER,

1 .00000000E+00 ,1 ,4HINCH,8,1 .O0QOQ0OQE+OO ,13H851 203 .163006

,

1 .000Q0000E-06 ,1 . 00000000E+03 ,6HAUTHOR, REORGANIZATION, 4 ,0;

406 1 406 0 124 2 124 0 108 4 108 0 108 6 108 0 108 8 108 0 108 10

108 0 410 12

410 0 406 13

406 0 124 14

124 0 108 15

108 0 108 16

108 0 108 17

108 0 108 18

108 0 410 19

410 0 406 20

406 0 124 21

124 0 108 22

108 0 108 23

108 0 108 24

108 0 108 25

108 0 410 26

410 0 406 27

406 0 108 28

108 0 108 29

108 0 108 30

108 0 108 31

108 0 410 32

410 0 110 33

0 15

0

0

0

1

0

1

0

1

0

1

0

0

0 15

0

0

0

1

0

1

0

10

1

0

0

0 15

0

0

0

1

01

01

0

1

0

0

0 15

01

0

1

01

0

1

0

0 10002

0 0000103 00D

NAME_PRP ID

0 00001030 0D

ROT MAT ID

0 000010201D

VIEW_PLN ID

0 000010201D

VIEW_PLN ID

0 00001020 ID VIEW_PLN ID

0 000010201D

VIEW_PLN ID

3 000000201D

VIEW ID

0 000010300D

NAME_PRP 2D

0 000010300D

ROT MAT 2D

0 00001020 ID VIEW_PLN ID

0 000010201D

VIEW_PLN ID

0 000010201D

VIEW_PLN ID

0 00001020 ID VIEW_PLN ID

17 00000020 ID VIEW 2D

0 00001030 0D

NAME_PRP 3D

0 0000103 00D

ROT MAT 3D

0 0 00010201D

VIEW_PLN ID

0 000010201D

VIEW_PLN ID

0 000010201D

VIEW_PLN ID

0 00001 0201D

VIEW_PLN ID

31 000000201D

VIEW 3D

0 000010300D

NAME_PRP 4D

0 000 010 201D

VIEW_PLN ID

0 000010201D

VIEW_PLN ID

0 000010201D

VIEW_PLN ID

0 00001 0201D

VIEW_PLN ID

0 000000201D

VIEW 4D

0 0000101 00D

1

12

3

41

23

45

67

8

9 10

11

12

13

14

15

16

17

18

19

20

21

22

23

24

25

26

27

28

29

30

31

32

33

34

35

36

37

38

39

40

4142

43

44

45

46

47

48

49

50

51

52

53

54

55

436
APPENDIX A - PART FILE EXAMPLES

110 1 4 1 0 LINE ID 56

110 34 1 1 10002 0 0 000Q10100D 57

110 1 4 1 0 LINE 2D 58

110 35 1 1 10002 0 0 000010100D 59

110 1 4 1 0 LINE 3D 60

110 36 1 1 10002 0 0 000010100D 61

110 1 4 1 0 LINE 4D 62

110 37 1 1 10002 0 0 0OQO1O10OD 63

110 1 4 1 0 LINE 5D 64

110 38 1 1 10004 0 0 00Q010100D 65

110 1 4 1 0 LINE 6D 66

110 39 1 1 10004 0 0 000010100D 67

110 1 4 1 0 LINE 7D 68

110 40 1 1 10004 0 0 0000101Q0D 69

110 1 4 1 0 LINE 8D 70

110 41 1 1 10004 0 0 0000101 00D 71

110 1 4 1 0 LINE 9D 72

406 42 1 1 0 0 0 0000103 00D 73

406 0 0 1 15 NAME__PRP 5D 74

404 43 1 1 0 0 0 000000201D 75

404 0 0 2 0 DRAWNG ID 76

110 45 1 1 10002 0 0 000000000D 77

110 1 2 1 0 LINE 10D 78

110 46 1 1 10002 0 0 00000000 OD 79

110 1 2 1 0 LINE 11D 80

110 47 1 1 10002 0 0 00000000 OD 81

110 1 2 1 0 LINE 1 2D 82

110 48 1 1 10002 0 0 000000000D 83

110 1 2 1 0 LINE 13D 84

110 49 1 1 10002 0 0 OOOOOOOOOD 85

110 1 2 1 0 LINE 14D 86

110 50 1 1 10002 0 0 OOOOOOOOOD 87

110 1 2 1 0 LINE 15D 88

110 51 1 1 10002 0 0 OOOOOOOOOD 89

110 1 2 1 0 LINE 16D 90

110 52 1 1 10002 0 0 OOOOOOOOOD 91

110 1 2 1 0 LINE 17D 92

110 53 1 1 10002 0 0 OOOOOOOOOD 93

110 1 2 1 0 LINE 18D 94

110 54 1 1 10002 0 0 OOOOOOOOOD 95

110 1 2 1 0 LINE 19D 96

110 55 1 1 10002 0 0 OOOOOOOOOD 97

110 1 2 1 0 LINE 20D 98

110 56 1 1 10002 0 0 OOOOOOOOOD 99

110 1 2 1 0 LINE 2 ID 100

110 57 1 1 10002 0 0 OOOOOOOOOD 101

110 1 2 1 0 LINE 2 2D 102

110 58 1 1 10002 0 0 OOOOOOOOOD 103

110 1 2 1 0 LINE 23D 104

110 59 1 1 10002 0 0 OOOOOOOOOD 105

110 1 2 1 0 LINE 24D 106

110 60 1 1 10002 0 0 OOOOOOOOOD 107

110 1 2 1 0 LINE 25D 108

110 61 1 1 10002 0 0 OOOOOOOOOD 109

110 1 2 1 0 LINE 26D 110

110 62 1 1 10002 0 0 OOOOOOOOOD 111

110 1 2 1 0 LINE 27D 112

406 ,1 ,7HCLIPPED; 00000001P 1 124,-0.67499 ,-0.171,0 .71774,1 .00728,-0.24401, 0 .96977,0 .00157, 00000003P 2 -0.821391 ,-0 .69631,-0 .17408,- 0.69631,4.613057 ,0,0; 00000003P 3

437
APPENDIX A - PART FILE EXAMPLES

108, 0. 67 499,0. 171, -0.7 1774, 5. 0055,0 ,6.390347,2.455541,-0.37923 5 , 00000005P 4

0 . ,0,0; 00000005P 5 108,-0.24401,0.96977,0.00157,3 .55308,0,3.025032,4.420965, 00000007P 6 2.494731,0. ,0,0; 00000007P 7 108,-0.67499,-0.171,0.71774,2.99094,0,0.992841,1.088152, 00000009P 8

5 .360119 , 0 . , 0 , 0; 00000009P 9 108,0.24401,-0.96977,-0.00157 ,1.9103,0,4.358156,-0.877273, 00000011P 10

2. 486153,0. ,0,0; 00000011P 11

410, 4,1. ,5, 7, 9, 11, 0,0, 0,1,1; 00000013P 12

406 ,1 , 5BRIGHT; 00000015P 13

124,0.,0.,-1.,0.,0.,1.,0.,0.,1.,0.,0.,0.,0,0; 00000017P 14

108,0.,0.,1.,36.,0,0.,0.,36.,0.,0,0; 00000019P 15

108,0. ,1 . ,0. ,24.59627 ,0,0. ,24.59627, 0. ,0. ,0,0; 00000021P 16

108,0.,0.,-l.,36.,0,0.,0.,-36.,0.,0,0; 00000023P 17

108,0.,-l.,0.,24.59627,0,0.,-24.59627, 0.,0.,0,0; 00000025P 18

410,3,1 . ,19 ,21,23, 25, 0,0,0, 1,15; 00000027P 19

406 ,1 ,3HTOP; 00000029P 20

124,1.,0.,0.,0.,0„,0.,-1.,0.,0.,1.,0.,0.,0,0; 00000031P 21

108,-l.,0.,0.,36.,0,-36.,0.,0.,0.,0,0; 00000033P 22

108,0.,0.,-l.,24.59627,0,0.,0.,-24.59627, 0.,0,0; 00000035P 23

108,1 . ,0.,0.,36. ,0,36. ,0. ,0. ,0. ,0,0; 00000037P 24

108,0.,0.,1.,24.59627,0,0.,0.,24.59627, 0.,0,0; 00000039P 25

410,2,1 .,33, 35, 37, 39, 0 ,0, 0,1, 29; 00000041P 26

406 ,1 , 5HFRONT; 00000043P 27

108,-1 . ,0 . ,0 . ,36 . ,0,-36 . ,0 . ,0 . ,0 . ,0 ,0; 00000045P 28

108,0 . ,1 . ,0. ,24.59627 ,0 ,0. ,24.59627, 0.,0.,0,0; 00000047P 29

108,1 . ,0. ,0. ,36. ,0,36. , 0 . ,0 . ,0. ,0,0; 00000049P 30

108, 0.,-l.,0., 24. 59627, 0,0., -24. 59627, 0.,0.,0,0; 00000051P 31

410,1,1. ,45,47,49,51 ,0,0,0,1,43; 00000053P 32

110,67 . ,0. ,0 . ,67. ,2. ,0. ,0,0; 00000055P 33

110,60. ,4. , 0 . , 6 0 . ,2. ,0.,0,0; 00000057P 34

110, 57., 4. ,0.,57. ,0.,0.,0,0; 00000059P 35

110,70. ,4. ,0. ,57. ,4. ,0. ,0,0; 0000006 IP 36

110,70. ,2. ,0. ,57. ,2. ,0. ,0,0; 00000063P 37

110,0.,40.,0.,0.,0.,0.,0,0; 0000006 5P 38

110,70. ,40 . ,0 .,0 . ,40 . ,0. ,0,0; 00000067P 39

110,70.,0.,0.,70.,40.,0.,0,0; 0000006 9P 40

110,0.,0.,0.,70.,0.,0.,0,0; 0000007 IP 41

406 ,1,7 HDRAWING

;

0000007 3P 42

404,4,13,51. ,29. ,27, 46., 8. ,41,7. ,24., 53 ,7. ,8. ,9,55,57,59,61,63, 0000007 5P 43

65,67,69,71,0,1 ,73; 0000007 5P 44

110,0. ,9. ,0. ,0.,9. ,-9. ,0,0; 00000077P 45

110,2.5,9. ,0. ,2.5,9., -9. ,0,0; 0000007 9P 46

110, 2. 5, 2. 5,0. ,2. 5, 2. 5, -9. ,0,0; 000000 81

P

47

110,20. ,2.5,0. ,20. ,2. 5, -9. ,0,0; 000000 83P 48

110,20.,0.,0.,20.,0.,-9.,0,0; 00000085P 49

110,0.,0.,0.,0.,0.,-9.,0,0; 000000 87P 50

110,0.,9.,-9.,0.,0.,-9.,0,0; 00000089P 51

110,2.5,9. ,-9. ,0. ,9 . ,-9. ,0,0; 00000091P 52

110,2.5,2.5,-9. ,2.5 ,9. ,-9. ,0,0; 00000093P 53

110,20. ,2. 5, -9. ,2. 5, 2. 5, -9. ,0,0; 00000095P 54

110, 20. ,0., -9. ,20. ,2. 5, -9. ,0,0; 00000097P 55

110,0.,0.,-9.,20.,0.,-9.,0,0; 00000099P 56

110,0. ,9. ,0.,0.,0.,0.,0,0; 00000101P 57

110,2.5,9. ,0. ,0. ,9. ,0., 0,0; 00000103P 58

110,2.5,2.5,0. ,2.5,9. ,0. ,0,0; 00000105P 59

110, 20. ,2. 5,0. ,2. 5, 2 . 5,0. ,0,0; 00000107P 60

110, 20., 0.,0., 20., 2. 5,0., 0,0; 00000109P 61

110,0.,0.,0.,20.,0.,0.,0,0; 00000111P 62

S 2G 4D 112P 62 T 1

438
APPENDIX B - ELECTRICAL ELECTRONIC

PRODUCT REPRESENTATION

APPENDIX B

ELECTRICAL/ELECTRONIC PRODUCT REPRESENTATION

INTRODUCTION

Purpose

The purpose of this appendix is to provide IGES implementors and users with a roadmap of the IGES representation of electrical/electronic product designs.

The topics of discussion will include (but are not limited to) design,

engineering, manufacturing, testing, and inspection.

Assumptions

The reader should have a basic understanding of electrical/electronic product

design using CAD/CAM/CAE tools, including (but not limited to) connectivity,

component descriptions, placement and routing, and the manufacturing

interface. Each topic will be discussed in general, but these discussions are

not intended to provide a tutorial in the subject.

CONNECTIVITY

In General

Forming a connection between two or more items requires the ability to represent the following:

(1) the exact location of each connection point

(2) the signal formed and its identification (if any)

(3) the physical connection between the items (if any)

The term "connect node" will refer to a database entity which represents the

exact location of connection. The term "link" will refer to the representation

of the signal formed, and "signal name" will refer to the signal identifier. The

439
APPENDIX B - ELECTRICAL ELECTRONIC

PRODUCT REPRESENTATION

term "join" will refer to the database entity or entities which represent the

physical connection between the items.

Each item to be connected requires a connect node to represent each possible

connection point of the item. A signal may be formed between any such items

by a link which references the connect nodes to be connected. This creates an

associativity between the connect nodes, and thus the connected items. The

signal name may be used to uniquely identify the particular signal formed.

The join may be used to provide a graphical representation of the signal. In electrical applications the join will most often be represented by a line

(schematic) or a widened line (printed wiring board).

In electrical applications, the items to be connected are typically electrical

components (i.e., resistor, 16-pin DIP, etc.). Most often, these components are represented by subfigures which are defined once, then referenced (instanced)

in the database for each occurrence of the component. Each pin of the

component is a potential connection point in a signal; thus each subfigure has a connect node defined for each pin. When such a subfigure is instanced, its connect nodes must also be instanced. This allows each connect node to participate in the unique signal to which it belongs. An instanced connect

node, when added to a signal, is different from its definition which is not a member of any signal.

These subfigures, representing electrical components, often contain text describing the component and its pins. In some cases (e.g., part number), this text is fixed and unchanging. In other cases (e.g., reference designator), the

text may be variable, and thus may not be filled in until the subfigure is

instanced. This text (sometimes called a "text node"), like the connect node,

is instanced along with its parent subfigure. In some cases, a connect node and

a text node are related (e.g., the connect node represents a component pin and

the text node represents the pin number).

440
APPENDIX B - ELECTRICAL ELECTRONIC

PRODUCT REPRESENTATION

In IGES

In IGES, the connect node is represented by the Connect Point entity. The

text node is represented by the Text Display Template entity. The Flow

Associativity entity represents a signal and contains the link, signal name, and

pointers to the join entities. The Network Subfigure entities (definition and

instance) represent electrical components which participate in signals. A

number of property entities will also be used, as mentioned below.

Network Subfigure Construction

A component is constructed using the Network Subfigure Definition entity.

The graphics representing the component geometry are referenced as for the

Subfigure Definition entity. In addition, a separate set of pointers to defining

Connect Point entities is provided. These Connect Point entities define the

locations and characteristics of the component's pins. Properties, for example

the Part Name property, may be attached to the Network Subfigure Definition

entity.

Connect Points

A component pin (or surface mounted device pad, IC I/O port, lead frame,

schematic symbol lead, etc.) is represented by the Connect Point entity. The

Connect Point entity is used in both logical and physical product designs. The

exact location in model space is specified, along with several characteristic

flags (connection type, function type, I/O direction). There is a pointer to the

parent Network Subfigure entity (definition or instance), which provides a much-needed association for signal processing. An additional Subfigure

Instance pointer is provided for Connect Point display. This allows a graphical

symbol to be displayed, representing the Connect Point. The pin number is provided in the Function Connect Point Identifier field, along with a pointer to a Text Display Template for pin number display. A pin function name is provided in the Connect Point Function Name field, along with a pointer to a Text Display Template for its display.

441
APPENDIX B - ELECTRICAL ELECTRONIC

PRODUCT REPRESENTATION

Signal Construction

A signal, representing one set of electrically common Connect Points, is constructed using the Flow Associativity entity. It contains pointers to other

associated Flow Associativity entities, the Connect Point entities

participating in the signal (this is the Link), and the Join entities representing

the geometry of the signal (either logical or physical). Also contained is a list of signal names which may be used to identify the signal, along with a set of

pointers to Text Display Template entities which may be used to display the

first signal name in a number of locations. Two characteristic flags determine

the signal type (logical or physical), and the function type (fluid flow or electrical signal).

A signal, then, is represented by one Flow Associativity entity pointing to a

set of electrically common Connect Points. This is the Link. The Join entities

represent the physical display geometry of the signal. For a schematic

(logical), a line without width is typically used. For a printed board (physical), a line with the Line Widening property is typically used. A number of signal names may be associated with the signal. Multiple displays of the first, or primary, name are possible.

The components participating in a signal are represented by the Network

Subfigure Instance entity. Note that the Connect Point entities "belonging" to a component are instanced along with the subfigure. This is necessary to allow

a subfigure to participate in a number of different signals, while retaining

unique component/pin identification. Each component is usually identified by

a reference designator. This is supplied by the Primary Reference Designator

field of the Network Subfigure. Any alternate reference designators may be

designated with the Reference Designator property, attached through the

normal property pointer mechanism.

Information Display

Throughout the above discussion, references to the Text Display Template

entity have been made. This entity allows text, embedded in an entity, to be

displayed without the redundant specification of the text string. There are

442
APPENDIX B - ELECTRICAL ELECTRONIC

PRODUCT REPRESENTATION

two reasons for this feature. First, it eliminates a possible source of error by

allowing the information to be specified in only one place. Second, it reduces

the file size overhead. This entity exists in two forms, absolute and

incremental. The absolute form provides an exact location for display of the

information, as in the display of a reference designator. The incremental form

provides an offset to be applied to the parent entity's location to provide the

exact location for display of information like pin numbers. When a direct

pointer for information display is provided, the base location is readily

determined from the parent entity's location such as when displaying a pin

number. In the case of property value display, the base location must be

determined by "remembering" the location of the property entity's parent

entity. This would occur when displaying the Part Name. Also in this case, the pointer to the Text Display Template entity is located in the- additional

pointers section of the property entity parameters.’

Additional Considerations

The situation is exactly the same for both logical and physical representations.

The only differences arise in the subfigure and 3oin entities used. In fact, a

file may contain representations for both the schematic and the board. The

Flow Associativity entity contains a type flag to indicate the connection type

(logical or physical). In this case, one Flow Associativity would represent the

logical connection and a second the physical connection. The two

associativities would be related by the pointers provided in the Flow

Associativity.

Figures

The following figures illustrate certain aspects of the above discussions.

Figure B-l illustrates the basic entity relationships. Figure B-2 and Table B-l

illustrate the usage of the Text Display Template. Figure B-3 illustrates an

actual implementaiton. Figure B-4 shows an example of logical and physical

signals and their relationships in the same file.

443
APPENDIX B - ELECTRICAL ELECTRONIC

PRODUCT REPRESENTATION

IGES ELECTRICAL ENTITY DESCRIPTIONS

The following entities (in entity number order) are the subset of IGES entities which

have particular meanings when used for electrical product data.

100 Circular Arc Entity

The electrical use of this entity is in the geometric representation of

component parts and their symbolic representations. In such usage, it is generally part of a subfigure. It may be used as a join entity. Its use may be

defined by a Level Function property or DE Level field.

102 Composite Curve Entity

The electrical use of this entity is in the geometric representation of

component parts and their symbolic representations. In such usuage, it is generally part of a subfigure. It may be used as a join entity. Its use may be

defined by a Level Function property or DE Level field.

106 Copious Data Entity

Forms 11, 12, and 13 of this entity may be used to implement the electrical

join (i.e., schematic or wiring diagram circuit connection lines). Any of these

forms may point to a Line Widening property. Examples of this entityproperty combination are circuit paths on a PC board or IC metalization, or as a bus in a schematic. Form 63, Simple Closed Area, may be used to define an

auto-router restriction area or a PC (or IC) defined area having special

attributes.

108 Plane Entity

Certain layers of PC design are designated as "ground", "power", or "heat

sink", and as such are large conductive areas. These layers, as well as larger

curved or rounded conductive areas on other layers, are best defined by the

Plane entity. Note that the form number indicates whether the bounded

region is positive or void (i.e., copper clad area or cutout).

444
APPENDIX B - ELECTRICAL ELECTRONIC

PRODUCT REPRESENTATION

110 Line Entity

The Line entity has several important uses in the electrical application. It may be used to construct component outlines, and to represent both logical

and physical connections (as a join entity). As a physical join entity, the Line

Widening property will most often be attached, giving the width of

metalization to be etched on the board. As a logical join entity, the line will

most typically be used without the Line Widening property.

116 Point Entity

The point entity is used to locate features that do not participate in electrical

connectivity, for example, a mounting hole.

124 Transformation Matrix Entity

A Transformation Matrix may be used to rotate subfigures to other than

normal (top up) positions. Generally, rotations are about the Z axis for PC and

IC constructs, but may be about any axis for 3D cabling files.

125 Flash Entity

The Flash entity may be used to represent a repetitive artwork feature which

is usually produced by photo-optical means. Examples include PC pads,

targets, clearances, and IC features.

132 Connect Point Entity

The Connect Point entity is used to represent a point of connection. A

subfigure defining an electrical component typically uses the Connect Point

entity to represent a pin of the logical or physical component or symbol. A

Connect Point may also be used in a "stand-alone" mode, representing a via

hole, for example.

445
APPENDIX B - ELECTRICAL ELECTRONIC

PRODUCT REPRESENTATION

212 General Note Entity

A General Note is used to display constant text. Design notes would require a General Note, for example.

302 Associativity Definition Entity

When the originating system provides for a relationship not included among the

IGES predefined associativities, this entity is required. Possible uses are to relate subfigures to entities in other databases (e.g., circuit analysis or text requirements) or for back-annotation purposes.

312 Text Display Template Entity

Form 0: absolute, Form 1: incremental

The Text Display Template may be used to display text which may be unique in each instance of the defined entity (A pin number, for example).

320 Network Subfigure Definition Entity

For PC and Cable usage, a subfigure usually represents a component and its required PC constructs. This entity is normally a library physical or logical

figure in the originating system.

402 Associativity Instance Entity

This entity relates other entities within a file to provide a "set" with a common meaning. Those associativities which are predefined by IGES are

identified by IGES form numbers (e.g., form 18: Flow). The user defined

associativities are defined by an entity 302 and its form number.

406 Property Entity

The use of a property to indicate the meaning or purpose of a geometric entity

applies to electrical constructs as well as general graphics. A Connect Point

446
APPENDIX B - ELECTRICAL ELECTRONIC

PRODUCT REPRESENTATION

entity may point to the Drilled Hole property. A Plane entity or Simple

Closed Area entity may point to the Region Restriction property. Any

property, however, may point to the Text Display Template, with the text

string specified in the property. In this case, the Text Display Template

locates the text display. This entity is an open-ended list allowing for

expansion to address future needs such as simulation, testing, inspection

applications, and extensions into electrical/electronic systems hierarchical

design.

412 Rectangular array Subfigure Instance Entity

414 Circular Array Subfigure Instance Entity

These entities may be used to instance multiple Network Subfigure Instances,

but must not be used for instancing Connect Points.

420 Network Subfigure Instance Entity

This entity allows an electrical component to be instanced in a number of

unique locations. Note that "owned" Connect Point entities must be instanced

with this entity.

447
APPENDIX B - ELECTRICAL ELECTRONIC

PRODUCT REPRESENTATION

r— 1 PER UNIQUE SUBFIGURE

Figure B-1 General Pointer and Entity Model

448
APPENDIX B - ELECTRICAL ELECTRONIC

PRODUCT REPRESENTATION

TABLE 1. TEXT TEMPLATE VALUES FOR SAMPLE SCHEMATIC

TEMPLATE TLEFT TRIGHT TTOP TBOT

WIDTH .10 .10 .10 .10 HEIGHT .13 .13 .13 .13 SLANT ANG. 0. 0. 0. 0. ROTN. ANG. 0. 0. 0. 0. MIRR. FLG 0 0 0 0

VRT/HORZ 0 0 0 0

DE FORM NO. 21 21 21 21 X (DX) -.09 -.03 + .03 + .03 Y (DY) + .03 + .03 -.15 + .1 Z(DZ) 0. 0. 0. 0. U1 P1-P8 P9-P16

U2 P1-P8 P9-P16

U3 P1-P4 P9-P12 P13-P16 P5-P8

PINS USING

THE TEXT

TEMPLATES

449
APPENDIX B ELECTRICAL ELECTRONIC

PRODUCT REPRESENTATION

NETWORK NETWORK

SUBFIG. SUBFIG.

DEFINITION DEFINITION

GEOMETRY

L \ A 1

CONN. PTS. GEOMETRY

l

CPNT 1 TL VCC

CPNT 8 TL GND

CPNT 10 TR SIG1

CPNT 15 TR <3-E»

_U£_

CPNT 16 TR CLCK

TEXT TEMPLATE

LEFT SIDE

CPNT 1 TL VCC

CPNT 5 TL CLCK

CPNT 8 TL GND

CPNT 9 TR

CPNT 16 TR

CONN. PTS.

NETWORK

SUBFIG. INSTANCE

NETWORK

SUBFIG. INSTANCE

NETWORK

SUBFIG. INSTANCE

I

CPNT 1 TL VCC

CPNT 3 TL SIG1

TEXT TEMPLATE

RIGHT SIDE

CPNT 8 TB GND

TEXT TEMPLATE

BOTTOM

CPNT 14 TT CLCK

9

<T>

CPNT 15 TT CLCK <&>

(FOUR)

SIGNALS)

FLOW AS. “VCC"

JOIN GEON.

-D FLOW AS. “SIG1”

JOIN GEON. FLOW AS. “GND"

JOIN GEON.

FLOW AS. “CLCK"

JOIN GEON. 3l

TEXT TEMPLATE

TOP

Figure B-3 Entity Relations Chart for Sample Schematic

450
APPENDIX B ELECTRICAL ELECTRONIC

PRODUCT REPRESENTATION

SCHEMATIC PHYSICAL

Figure B-4 Schematic/Physical Diagram for Sample Schematic

451
THIS PAGE LEFT BLANK

452
APPENDIX C - PLANT FLOW SHEET

PRODUCT REPRESENTATION

APPENDIX C

PLANT FLOW SHEET REPRESENTATION

Flowsheet Characteristics

Process flowsheets carry several important types of information which determine what

data structures must be present. They must show:

1. The identity of the process streams or lines flowing through the plant. Process

and instrumentation diagrams typically show line designation, size, spec, and

stream direction.

2. The identity of "nozzles" on equipment to which line connections are made, and

into and out of which process streams flow.

3. The identity of equipment (i.e., valves, columns, pumps) which control, mix,

pump and process the stream.

4. The association of "nozzles" with the equipment to which they belong.

5. The association of the beginning and end of each stream with unique nozzles.

6. Indication of where a line is continued if it is too large for a single sheet and is continued elsewhere.

Support for Flowsheets

The graphics of a piping and instrument diagram will typically be composed of lines, arcs, and text. Components will consist of symbols (subfigure defintions) which are defined once by a set of lines and arcs and then referenced (as subfigure instances) as many times

as needed.

453
APPENDIX C - PLANT FLOW SHEET

PRODUCT REPRESENTATION

A piping or instrument line is described by a path associativity entity which lists the from

and to nozzles (points to their connect point entities) and then lists the in-line

components. Properties can be attached to any entity and Pipe Nominal Size and Line

Spec Name Properties would be attached to pipe line path entities.

Plant Flow Sheet Example

A simple flowsheet is shown in Figure C-l. The way the flowsheet would appear on paper

is shown in Figure C-la. The recommended assignment of connection points is shown in Figure C-lb.

An exploded view of the flowsheet showing the conceptual entities to be used to describe

the flowsheet is given in Figure C-2a. These include two subfigures, "tank" and "valve",

and four connect points belonging to them. Subfigures are defined at one time in the file for multiple use. When subfigures are used, each use is an "instance" of previously defined

subfigure definitions. Two additional connect points are also shown to permit flow paths

to begin and end properly. Five line entities appear to visually indicate how things are connected.

Logically the process designer has assigned these entities to pipelines or streams

depending on what is being described. The logical flow paths for two process streams

"A" and "B" are shown in Figure C-2b. Pipelines and streams are ordered sequences of

equipment. When the line or stream reaches a point where two continuing paths are

possible it must be told how to proceed. In some practical cases, both continuing paths

may belong logically to the line or stream. A mechanism to indicate these continuations

is provided by the flow path entity.

Describing how to encode a flowsheet involves:

(1) How to define the subfigure,

(2) How to instance the subfigure and the connect points it owns,

(3) How to define graphic lines which give pipelines and streams their appearance,

and

(4) How to define the pipelines and streams themselves.

The entities which encode this flowsheet are given in Table C-l. The entity numbers

given are the DE pointers to the example file shown in Table C-2.

454
appendix C - PLANT FLOW SHEET

PRODUCT REPRESENTATION

FIGURE C-la FLOWSHEET APPEARANCE

FIGURE C-lb REQUIRED CONNECTION POINTS

455
APPENDIX C - PLANT FLOW SHEET

PRODUCT REPRESENTATION

/

/

"s.

FIGURE C-2a CONCEPTUAL FLOWSHEET ENTITIES

FIGURE C-2b LOGICAL FLOW PATH FOR STREAMS

456
APPENDIX C - PLANT FLOW SHEET

PRODUCT REPRESENTATION

TABLE C-l

ENTITIES IN PI & D TEST CASE

itity // Type Remarks

1 Network subfigure def Column

3 Network subfigure def Valve

5 Line Part of column

7 Circular arc II

9 Line II

11 Circular arc II

13, 15 Connect point Valve nozzle

17-29 Lines Part of valve

31 General note Miscellaneous drawing text

33 Text display template Flow path name display

35 Network subfigure inst. Instance of column

37 Network subfigure inst. Instance of valve

39, 41 Connect point Instance of tank nozzles

43, 45 Connect point Instance of valve nozzles

47 Connect point Branch point

49 Connect Point Flow path end

51-59 Lines Geometry of connecting path

61, 63, 65 Nominal size property

67 Part number property

69 External reference Continuation of flow path

71, 73 Flow associativity

75, 77 Text display template Templates for subfigure

name reference designator

display

79 Text display template Template for display of

nozzle names

81-89 Line Continuation symbol

91 Line spec property A100

93 External reference file list 95 External reference file index

457
APPENDIX C - PLANT FLOW SHEET

PRODUCT REPRESENTATION

Network Subfigure Definitions

The definitions of the tank and valve subfigures are shown in Figures C-3a and C-3b.

Each subfigure consists of the Network Subfigure Definition entity, geometry

entities, and connect point entities. The tank is defined by entities 1,5,7,9 and 11. The Network Subfigure Definition entity #1 contains lists of the geometry entities

(#5,7,9, and 11). This is merely a definition which is "instanced" when actually

needed.

The valve has a similar form. The valve Network Subfigure Definition entity #3

points to geometric entities #17 through 29, and to Connect Point entities 13 and

15.

Network Subfigure Instances

When the tank and valve network subfigures are instanced, the subfigure's connect

points will be duplicated and associated with the instance. The geometric entities

will not be duplicated. Figure C-4a shows the subfigures as instanced in the

flowsheet with instance entities #35 ("tank") and #37 ("valve"). Note that the

subfigures may be scaled when they are instanced. In the "valve" example different

scale factors are used in the x and y axes. Independent x and y axis scaling is often

used by CAD vendors to "fit" their symbols to the drawing. Network subfigure

instance #35 points to subfigure definition #1 and to the new duplicated connect

points #39 and #41. Similarly, Network Subfigure Instance #37 points to Subfigure

Definition #3 and to duplicate connect points #43 and 45.

Geometric Entities for Pipeline or Stream

Lines will appear on the drawing to indicate graphically how symbols are connected

into pipelines and streams. These geometric entities alone do not logically connect

symbols. This is done by Flow Path Associativity instance entities. The geometric

entities are lines #51 through #59.

458
APPENDIX C - PLANT FLOW SHEET

PRODUCT REPRESENTATION

FIGURE C-3a ENTITY #1 TANK

“ ”1 T” “ “I

FIGURE C-3b ENTITY #3 VALVE

459
APPENDIX C - PLANT FLOW SHEET

PRODUCT REPRESENTATION

#35

N

\

FIGURE C-4a GEOMETRY ENTITIES

FIGURE C-4b ATTRIBUTES

" N

/ \

#73

FIGURE C-4c FLOW PATHS

460
APPENDIX C - PLANT FLOW SHEET

PRODUCT REPRESENTATION

Attributes

Three specific properties (attributes) are provided for flowsheets. These are part

number, nominal size, and (flow) line specification. Figure C-4b shows the

properties used for the test case. These are implemented by three forms of the

property entity. The entities in the test case are #61 through 67 and #91.

Flow Paths

Figure C-4c shows an assignment of flow paths. Two flow path entities are

required, #71 and 73. Each Flow Path Associativity entity contains an ordered list

of the connect points along the path and a separate list of the geometry entities

representing the path. Where a branch occurs one path may point to one or more

other paths. In the example flow path #71 lists path #73 as a continuation. These

points are bi-directional, so flow path #73 contains a list of the entities (#71) which

point to it. The flow path is also the entity to which the Line Specification property

is attached. Note that a rather arbitrary flow path assignment was made by the

process engineer. Other assignments are possible and could be encoded.

Text Templates

Text templates are used to control display of the text which is actually contained in the Subfigure Instance and connect point entities. There are two uses of Text

Template entities in this example. The first type of use is to control display of the names (reference designators) of the tank and valve instances. Absolute templates

#75 and #77 are used for this. The tank nozzles (connect points #39 and #41) both

have their nozzle names (connect point function identifier) displayed with the same

text size and location offset relative to the connect point location. Both connect

point entities point to the same Incremental Text Template entity #79.

461
APPENDIX C - PLANT FLOW SHEET

PRODUCT REPRESENTATION

External References

Flow path //71 continues offpage, i.e., the path is logically continued on another

flowsheet. Three pieces of information must be matched to make this continuation:

1. Line designation or number.

2. Drawing on which the path is continued, and

3. "Incoming" or "outgoing" connectors which match to the start or end of the

path on the page.

This is handled by two mechanisms:

1. The External Reference entity which points (using a unique symbolic name)

to the next connect point of the path upon which continuation is made, and

to the file in which the drawing is contained. The connect point function

identifier field is used to carry the drawing name and a text template is used to display it. File names are recommended to be constructed from

the drawing name by the pre-processor.

2. The position of connect point within a flow path to the external flow path on the external flowsheet will determine whether it is logically "incoming"

or "outcoming.

We will now implement these pointer structures for the example (see figure C-5.)

Flow path #71 ends at external reference entity #69. It points by a unique name

'I834-6"-C121' to a connect point in file 'XYZOIL. PROCESS.5678'. These external

reference names must be unique. Typical CAD systems that do not maintain a

globally unique name for a connect point may construct one using some set of

conventions. The unique name 'I834-6"-C12r is typical of what can be constructed

by a pre-processor using 'I' for incoming and '834-6"-C121', the line number, size,

and spec. The file name 'XYZOIL.PROCESS.5678' is constructed from the connect

point function identifier string '3678' using the root string file name entry in the

External Reference Entity. The External Reference File List entity #93 carries this

file name also, in the referencing file.

462
FILE

XYZOIL

P&ID

1234

FILE

XYZOIL

P&ID

5678

APPENDIX C - PLANT FLOW SHEET

PRODUCT REPRESENTATION

I

L

1

J

463

FIGURE

C-5
APPENDIX C - PLANT FLOW SHEET

PRODUCT REPRESENTATION

In the external flowsheet, an External Reference File Index entity will list the

symbolic name 'I834-6-C121' and reciprocal entities also exist to allow the external

flowsheet to continue back into the referencing flowsheet. The flow path begins

with an external reference entity '0834-6"C121' in file 'XYZOIL.PROCESS.1234'. It

will also contain an external reference file list repeating this file name. There will

also be an External Reference File Index entity #95 containing the symbolic name

'0834-6-C121' a pointer to connect point #49.

Encoded Flowsheet

The encoded flowsheet is shown in Table C-2.

464
APPENDIX C - PLANT FLOW SHEET

PRODUCT REPRESENTATION

TABLE C-2 PLANT FLOWSHEET EXAMPLE

PIPING AND INSTRUMENTATION DIAGRAM IGES EXAMPLE S 1 1H, , 1H; , 12HPI&D EXAMPLE, 19HXYZOIL. PROCESS. 1234, 10H HYBRID 1 . 0 , 1 H2 , 32 , 38 , G 1 6 , 308 , 1 5 , 1 2HPI&D EXAMPLE, 0. 100000E+01 , 1 ,4HINCH,3 , .06 , 13H851 1 15 .233700 , G 2

0.0001 ,10000. , 10HP.W. ROURKE , 3HORG ,4,0; G 3

320 1 1 0 1 0 0 000 1 0200D 1 320 0 1 1 4 D 2

320 2 1 0 1 0 0 000 1 0200D 3

320 0 1 1 4 D 4 110 3 1 0 1 0 0 000 1 0000D 5

110 0 1 1 0 D 6

100 4 1 1 2 5 0 000 1 0000D 7

100 2 1 1 0 D 8

110 5 1 1 1 5 0 000 1 OOOOD 9

110 2 1 1 0 D 10

100 6 1 1 1 5 0 00010000D 1

1

100 2 1 1 0 D 12

132 7 1 1 2 5 0 00020400D 13

132 2 1 1 0 D 14

132 8 1 1 2 5 0 00020400D 15

132 2 1 1 0 D 16

110 9 1 1 2 5 0 000 1 OOOOD 17

110 2 1 1 0 D 18

110 10 1 1 1 5 0 000 1 OOOOD 19

110 2 1 1 0 D 20

110 1

1

1 1 1 5 0 000 1 OOOOD 21

110 2 1 1 0 D 22

110 12 1 1 2 5 0 000 1 OOOOD 23

110 2 1 1 0 D 24

110 13 1 1 2 5 0 00010000D 25

110 2 1 1 0 D 26

110 14 1 1 1 5 0 00010000D 27

1 10 2 1 1 0 D 28

110 15 1 1 2 5 0 000 1 OOOOD 29

110 2 1 1 0 D 30

212 16 1 1 1 5 0 00000 1 OOD 31

212 2 1 1 0 D 32

312 18 1 1 1 5 0 000 1 020 1

D

33

312 2 1 1 0 D 34

420 19 1 1 1 5 0 00000300D 35

420 2 1 1 0 D 36

420 20 1 1 2 5 0 00000300D 37

420 2 1 1 0 D 38

132 21 1 1 2 5 0 00020400D 39

132 2 1 1 0 D 40

132 22 1 1 1 5 0 00020400D 41

132 2 1 1 0 D 42

132 23 1 1 2 5 0 00020400D 43

132 2 1 1 0 D 44

132 24 1 1 1 5 0 00020400D 45

132 2 1 1 0 D 46

132 25 1 1 1 5 0 00020400D 47

132 2 1 1 0 D 48

132 26 1 1 1 5 0 00020400D 49

132 2 1 1 0 D 50

465
APPENDIX C - PLANT FLOW SHEET

PRODUCT REPRESENTATION

110 27 1 1 2 5 0 00000000D 51

110 2 1 1 0 D 52

110 28 1 1 2 5 0 00000000D 53

110 2 1 1 0 D 54

110 29 1 1 1 5 0 00000000D 55

110 2 1 1 0 D 56

110 30 1 1 2 5 0 00000000D 57

110 2 1 1 0 D 58

110 31 1 1 1 5 0 00000000D 59

110 2 1 1 0 D 60

406 32 1 1 1 5 0 01000000D 61

406 2 1 1 13 D 62

406 33 1 1 2 5 0 0 1 000000D 63

406 2 1 1 13 D 64

406 34 1 1 1 5 0 0 1 OOOOOOD 65

406 2 1 1 13 D 66

406 35 1 1 1 5 0 0 1 OOOOOOD 67

406 2 1 1 9 D 68

416 36 1 1 1 5 0 01 OOOOOOD 69

416 2 1 1 2 D 70

402 37 1 1 2 5 0 0 1 000300D 71

402 2 1 1 18 D 72

402 39 1 1 2 5 0 01000300D 73

402 2 1 1 18 D 74

312 40 1 1 1 5 0 000 1 020 1

D

75

312 2 1 1 0 D 76

312 41 1 1 2 5 0 000 1 020 1

D

77

312 2 1 1 0 D 78

312 42 1 1 1 5 0 000 1 020 1 D 79

312 2 1 1 0 D 80

110 43 1 1 2 5 0 OOOOOOOOD 81

110 2 1 1 0 D 82

110 44 1 1 2 5 0 OOOOOOOOD 83

110 2 1 1 0 D 84

110 45 1 1 1 5 0 OOOOOOOOD 85

110 2 1 1 0 D 86

110 46 1 1 2 5 0 OOOOOOOOD 87

110 2 1 1 0 D 88

110 47 1 1 1 5 0 OOOOOOOOD 89

110 2 1 1 0 D 90

406 48 1 1 1 5 0 0 1 OOOOOOD 91

406 2 1 1 14 D 92

406 49 1 1 2 5 0 0 1 OOOOOOD 93

406 2 1 1 12 D 94

402 50 1 1 1 5 0 0 1 OOOOOOD 95

402 2 1 1 12 D 96

320 , 0 , 4HTANK , 4 ,

5

,7 ,9, 1 1 ,i; IP 1 320 ,0 ,5HVALVE,7 , 17 ,19 ,21 ,23,25, 27,28,1 ,

,

,2,13,15; 3P 2

110 , -0.5 ,2 .5,0. 0, -0 .5 ,0.0, 0.0 > 5P 3

100 > o.o, 0 .0,0. 0, -0 .5 ,0.0, 0.'5,0.0; 7P 4 110 , 0.5, 0. o o o J 0 .5 ,2.5 ,0.0 1 9P 5

100 , 0.0, 0 .0,2. 5

,

0 .5 ,2.5, -0 .5,2.5; IIP 6

132 , -2.0 ,0 .0,0. 0, ,1

,

2, 1 HA , , , , , , , 3

;

1 3 P 7

132 , 2.0 ,0 .0,0. 0, ,1

,

2, 1HB,

,

, ,

,

, ,3; 15P 8

110 , 2.0, 0. 5,0.0 J -2 .0 , -0 . 5 , 0 . (3; 1 7 P 9

466
APPENDIX C - PLANT FLOW SHEET

PRODUCT REPRESENTATION

110, -2. 0,0. 5, 0.0, -2. 0,-0. 5 ,0.0; 2 1 P 1

1

110, 2. 0,0. 5, 0.0, 2. 0,-0. 5 ,0.0; 23P 12

110, 0.0, 0.0, 0.0, 1.0, 2. 0,0.0; 25 P 13

110, 0.0, 0.0, 0.0, -1 .0 ,2.0 ,0.0; 27P 14

110, 1.0, 2. 0,0.0, -1 .0,2. 0,0.0;

212,1 , 12,0.200000E+01 , 0 . 1 64063E+00 , 1 ,1.570796,0.0,0,0,

29P 15

31P 16

.400000 E+ 01 ,0. 800000 E+ 01 ,0.0,12HXYZ OIL PI&D; 31P 17

312.1

.2.0.

1 . . .0. .0.0. 4. 0.8. 0.0.0;

420.1 .2.

0.

2. 0.0. 0.2.0. . .1 . . .2.39.41

;

33P 18

35P 19

420,3,5.5,3.0,0.0, ,, ,1 ,, ,2,43,45,1 ,71 ,2,67,61; 37P 20

132,5.0,0.0,0.0, ,1 , 2 , 6H0UTLET , 7 9 , , , ,2, ,35; 39P 21

132,3.0,3.0,0.0, ,1 ,2, 5HINLET, 79, , , ,1 , ,35; 4 1 P 22

132,5.0,3*0,0.0, , 1 ,2, , , , , , , ,37

;

43P 23

132,6.0,3.0,0.0, , 1 ,2, , , , , , , ,37

;

45P 24

132,8.0,3.0,0.0, ,1 ,2; 47P 25

132,10.0,3.0,0.0,1 ,2; 49P 26

110, 3- 0,3. 0,0.0, 5. 0,3. 0,0.0, 1,71, 1,61; 5 1 P 27

110, 6. 0,3. 0,0.0, 8. 0,3. 0,0.0, 1,71, 1,63; 53P 28

110, 8. 0,3. 0,0.0, 10.0,3.0,0.0, 1,71, 1,63; 55P 29

1 10, 3. 0,6. 0,0.0, 8. 0,6. 0,0.0, 1,73, 1,65; 57P 30

1 10, 8. 0,3. 0,0.0, 8. 0,6. 0,0.0, 1,73, 1,65;

406,2,12. , 3HI PS

;

59P 31

6 1 P 32

406,2,10. , 3HIPS

;

63P 33

406,2,4. , 3HIPS

;

406 , 4 , 5H9802 1 , , ,

;

65P 34

67P 35

416,1 , 19HXYZ0IL. PROCESS. 5678 , 1 1 H0834-6" C 1 2 1

;

69P 36

402,2,0,6,4,1,1,1,1,2,39,43,45,47,49,69,51,37,53,55,

1 1H834-6"-C121 ,33,73;

71P 37

7 1

P

38

402,2,0,2,2,1,0,0,1,2,47,41,57,59,1,71,1,77; 73P 39

312,0.9,0.1 ,, ,0. ,0,0,1 .5,4.5, 0.; 75P 40

312,0.4,0.1 , , ,0. ,0,0, 5. 2, 4. 1 ,0.

;

77P 41

312, 1.0,0.1,,,0., 0,0, 0.1, -0.1,0.; 79P 42

110, 10.0,2.75,0.0, 10.75,2.75,0.0; 81 P 43

110, 10.75,2.75,0.0, 11.0,3-0,0.0; 83P 44

110, 11.0,3-0,0.0, 10.75,3-25,0.0; 85P 45

110, 10.75,3.25,0.0, 10.0,3.25,0.0; 87P 46

110, 10.0,3.25,0.0, 10.0,2.75,0.0;

406 , 1

, 4HA 1 00

;

89P 47

91P 48

406,1 , 19HXYZ0IL. PROCESS. 5678; 93P 49

402,1 , 1 1HI834-6"C121 ,49; 95P 50

1 G 3D 96P 50 T 1

467
THIS PAGE LEFT BLANK

468
APPENDIX D - SPLINE REPRESENTATIONS

APPENDIX D

SPLINE REPRESENTATIONS

D1 INTRODUCTION

Section 3 of the Specification includes four different types of spline representations:

a. A Parametric Piecewise Cubic Polynomial (for curves)

b. A Rational B-Spline Curve

c. A Grid of General Bicubic Patches (for surfaces).

d. A Rational B-Spline Surface

Most of the spline types used in CAD/CAM systems can be mapped into these

representations without change in shape. Spline types supported in Section 3 of

this Specification include parametric cubics, piecewise linear, Wilson-Fowler,

modified Wilson-Fowler, rational and non-rational B-splines, rational and nonrational cartesian product B-spline surfaces, and Coons patches. Spline types not

supported include splines under tension and extended Coons patches.

Software to convert between parametric spline curves or surfaces and the

corresponding rational B-spline curves or surfaces is available from the IGES office

at the National Bureau of Standards. Materials provided include a magnetic tape

of Pascal source code, a listing of the code, and accompanying documentation.

D2 SPLINE FUNCTIONS

In Section 3.8 of this Specification, spline curves are represented by a number of

cubic spline functions, one for each of the X,Y,Z coordinates. Each cubic spline

function S(u) is defined by

a. N: The number of segments,

b. T(1),...,T(N+1): The endpoints and the breakpoints separating the cubic

polynomial segments,

c. A(i),B(i),C(i),D(i), i=l,...,N: The coefficients of the polynomials representing

the spline in each of the N segments,

469
APPENDIX D - SPLINE REPRESENTATIONS

d. CTYPE: The spline type (l=linear, 2=quadratic, 3=cubic, 4=Wilson-Fowler,

5=Modified Wilson-Fowler, 6=B-spline) of the originating system.

See section 3.8

e. H: Degree of continuity. See section 3.8.3.

To evaluate the spline at a point "u", first determine the segment containing

"u", i.e., the segment "i" such that T(i)4> u 4,T(i+l)> then evaluate the cubic

polynomial in that segment, i.e., compute

S(u) = A(i) + B(i)*(uu) + C(i)*(uu)**2 + D(i)*(uu)**3

where uu = u-T(i).

The polynomial is written in terms of the relative displacement uu (rather

than u) so that the values of the spline at the breakpoints can be read directly

out of the representation (i.e., S(T(i)) = A(i), i=l, ..., N, and S(T(N+1)) = TPO).

Computations using the relative displacement also have less floating-point

roundoff error.

This particular "piecewise polynomial" form is only one of many used to represent the spline segments in CAD/CAM systems. Other representations

employed include:

a. End points E1,E2 and end slopes S1,S2: The spline can be evaluated

using the "Hermite" basis (DEB078, p. 59).

b. Values at four points: The spline value can be computed from the

Lagrange or Newton interpolation formulae (DEB078).

c. End points and "control" points: There are a number of schemes for computing splines from control points which will not be described here.

DeBoor (DEB078) gives techniques for conversion between these

representations.

470
APPENDIX D - SPLINE REPRESENTATIONS

Splines can also be represented as a linear combination of the B-spline basis

functions. In CAD/CAM systems, B-splines have been used directly in curve

fitting (e.g., the B-spline Bezier polygon (GORD74)) and indirectly in various

spline calculations (e.g., computing a cubic spline interpolate). For every set

of breakpoints T(1),...,T(N+1) and degree of continuity H, a set of B-spline

functions B(l,u),B(2,u),...,B(n',u) can be constructed (DEB078). Then, for any

piecewise polynomial S(u) with these breakpoints and continuity there is a set

of B-spline coefficients a(l),..., a(n') such that S(u) can be represented as a

linear combination of these B-splines

S(u) = a(l)*B(l,u) + a(2)*B(2,u) + ... + a(n')*B(n',u)

where n' = (N-l)*(3-H)+4.

B-splines can be computed from piecewise polynomials and vice versa (DEB078, p. 116 and Subroutine BSPLPP).

Several other types of spline representations (e.g., cardinal bases) have been

employed, but they are much less common and do not appear to present a problem for this Specification.

D3 SPLINE CURVES

The comments in this section pertain primarily to section 3.8.

Since curves in CAD/CAM problems are frequently many-valued, spline

functions cannot represent such curves adequately. The most common

approach to curve fitting is to parameterize the curves, i.e., to represent

each curve as either two or three spline functions (one for each coordinate)

X(u) = Sx(u),

Y(u) = Sy(u), and

Z(u) = Sz(u)

which sketch out the curve as the parameter u varies from T(l) to T(N+1).

471
APPENDIX

D4

- SPLINE REPRESENTATIONS

All of the spline function representations of the previous section can be

generalized to parametric curves and the algorithms for converting spline curves from one representation to the other follow easily from multiple

applications of the corresponding function conversion algorithms.

Wilson-Fowler Curves: In the early sixties, the Wilson-Fowler spline (a

special case of parametric cubics) was developed for curve fitting (IITR68).

It is still used in many turnkey drafting systems. In the Wilson-Fowler

representation, each spline segment is defined in a separate coordinate

system whose X-axis begins at one endpoint of the segment and passes

through the other. Each spline segment is then defined by a cubic spline

function Swf(x) and the coordinates of the two endpoints. These WilsonFowler splines can be converted to splines defined in Section 3.8 by rotating

the parametric spline (u,Swf(u)) back into the current coordinate system;

however, most types of splines defined in Section 3.8 cannot be converted to Wilson-Fowler splines.

RATIONAL B-SPLINE CURVES

The comments in this section pertain primarily to section 3.16.

A rational B-spline curve is expressed parametrically in the form

K

2 wwpafe.to

K

2 w(i)b

i(t)

1=0

where the notation is interpreted as follows.

The W(i) are the weights (non-zero real numbers).

3 The P(i) are the control points (points in R ).

472
APPENDIX D - SPLINE REPRESENTATIONS

The are the B-spline basis functions. These are defined as soon as their

degree, M, and underlying knot sequence, T, are specified.

This is done as follows:

Let N = K - M + 1. Then, the knot sequence consists of the non-decreasing

The curve itself is parametrized for V(0)^t^V(l) where

T(0)^V(0)4V(1)4T(N).

The B-spline basis functions b^ are each non-negative piecewise polynomials

of degree M. The function b^ is supported by the interval lT(i—M), 7’(/+l)].

Between any two adjacent knot values T(j), T(j+1) the function can be

expressed as a single polynomial of degree M.

For any parameter value t between T(0) and T(N) the basis functions satisfy

the identity

If the weights are all positive, the curve G(t) is contained within the convex

hull of its control points.

There are a number of ways to precisely define the B-spline basis functions.

A recursive approach proceeds as follows.

Let N(t |t. m

,...,t. +

^) denote the B-spline basis function of degree m

supported by the interval

With this notation, the degree 0 functions are simply characteristic functions

of a half-open interval.

I .v 1 if a^t<b

Nyt

| a,b) — q

otherwise

set of real numbers; T(-M), ..., T(0), ..., T(N), T(N+M)

K

b.(t) = 1

473
APPENDIX D - SPLINE REPRESENTATIONS

The degree k functions are defined in terms of those of degree k-1.

N(t

j s0 sk) -

( t-s^Njt js0,

. . . ( sk-t)N(t |si, ...,sk)

sk-l - s0 sk ~ 5 1

Since some of the denominators will be 0 in the case of multiple knots, the

convention 0/0 = 0 is adopted in the above definition.

Rational Bezier curves (and surfaces) can be expressed exactly as rational Bspline curves (and surfaces). (BLOM82).

Software to convert between parametric spline curves or surfaces and the

corresponding rational B-spline curves or surfaces is available from the IGES

office at the National Bureau of Standards. Materials provided include a magnetic tape of Pascal source code, a listing of the code, and accompanying

documentation.

D5 SPLINE SURFACES

The spline surface defined in Section 3.9 is the analog of the spline curve

defined in section 3.8, i.e., it is also pieced together out of other primitive

functions. The surface is a grid of parametric bicubic patches defined by:

a. M: The number of grid lines in u,

b. TU(1),...,TU(M+1): The breakpoints in u (u values of grid lines),

c. N: The number of grid lines in v,

d. TV(1),...,TV(N+1): The breakpoints in v (v values of grid lines),

e. Ax(i,j),Bx(i,j),...,Ay(i,j),...,Az(i,j),..., for i = l,...,M^ j = l,«..,N:

The M*N sets of 3*16 coefficients defining the bicubic polynomial for each of the three coordinates of the patch,

474
APPENDIX D - SPLINE REPRESENTATION

f. CTYPE: The spline type. (Ulinear, 2=quadratic, 3=cubic, 4=WilsonFowler, 5=Modified Wilson-Fowler, 6 = B-spline), and

g. PTYPE: The patch type. (l=Cartesian product, 0=unspecified).

To evaluate the spline at a point "u,v", first determine the patch containing

the point "u,v" in the parameter grid, i.e., the patch "i,j" such that

TU(i)^ u ^TU(i+l) and TV(j) 4. v ^TV(j+l), then evaluate the bicubic

polynomial in that patch, i.e., compute

X(u,v) = Ax(i,j) *vv**0 *uu**0 + Bx(i,j) *vv**0 *uu**l

+ Cx(i,j) *vv**0 *uu**2 + Dx(i,j) *vv**0 *uu**3

+ Ex(i,j) *vv**l *uu**0 + Fx(i,j) *vv**l *uu**l

+ Gx(i,j) *vv**l *uu**2 + Hx(i,j) *vv**l *uu**3

+ Kx(i,j) *vv**2 *uu**0 + Lx(i,j) *vv**2 *uu**l

+ Mx(i,j) *vv**2 *uu**2 + Nx(i,j) *vv**2 *uu**3

+ Px(i,j) *vv**3 *uu**0 + Qx(i,j) *vv**3 *uu**l

+ Rx(i,j) *vv**3 *uu**2 + Sx(i,j) *vv**3 *uu**3

Y(u,v) = Ay(i,j) . . .

Z(u,v) = Az(i,j) . . . where uu = u - TU(i) and vv = v - TV(j)

The patches in the spline surface are equivalent to the bicubic surface patch

(or the Coons patch, see (ROGE76, p. 170) for the conversion details). The

parameters of the Coons patch are given as the corner points, corner slopes,

and twist vectors (similar in spirit to the point/slope representation for

curves).

However, because the Specification spline is more general than splines found

in many CAD/CAM systems (e.g., the APT Wilson-Fowler spline), shapepreserving transformations out of the Specification spline format may not be

possible. Difficulties encountered include restrictions such as uniform

475
APPENDIX D - SPLINE REPRESENTATIONS

breakpoint spacing and smooth second derivatives. In these cases, the

conversion must be accomplished by an interpolation or smoothing process.

D6 RATIONAL B-SPLINE SURFACES

The comments in this section pertain primarily to section 3.17.

A rational B-spline surface is expressed parametrically in the form

K1 K2

7; W(i,j)Pa,j)b.(s)b.(t)

U

G(s,t) = K1 K2

2 wa,j)b.ttbj(t>

i=0 j=0

where the notation is analogous to that used for rational B-spline curves.

The W(i,j) are the weights (non-zero real numbers).

3 The P(i,j) are the control points (points in R ).

The b. are the B-spline basis functions of degree M 1 determined by the knot

sequence S(-M 1),...,S(N1+M 1). The b^ are the B-spline basis functions of

degree M2 determined by the knot sequence T(-M2),...,T(N2+M2). Here,

NUK1-M1 + 1 and N2=K2-M2+1.

The surface itself is parameterized for U(0)^s^U(l) and for V(0)4t^V(l)

where S(0)^U(0)<U(1)4S(N1) and T(0)£V(0)<V(1)4T(N2). Rational Bezier

surfaces (and curves) can be expressed exactly as rational B-spline surfaces

(and curves). (BLOM82).

If the surface is periodic with respect to the first parametric variable, set PROP4 to 1; otherwise set PROP4 to 0. If the surface is periodic with

respect to the second parametric variable, set PROP5 to 1; otherwise set PROP5 to 0.

£

i=0

476
APPENDIX D - SPLINE REPRESENTATIONS

Software to convert between parametric spline curves or surfaces and the

corresponding rational B-spline curves or surfaces is available from the IGES

office at the National Bureau of Standards. Materials provided include a magnetic tape of Pascal source code, a listing of the code, and accompanying

documentation.

477
THIS PAGE LEFT BLANK
APPENDIX E CONIC ARCS

APPENDIX E

CONIC ARCS

Conic arcs as specified by the IGES standard are extremely sensitive to the data in two distinct ways:

(a) Accuracy

It is numerically sensitive; small changes in the coefficients can cause

large changes in the locations of the points satisfying the conic equation.

(b) Stability

The determination of the conic type depends upon whether certain

invariants are positive, zero or negative. Working in floating point

arithmetic, a machine value of 0.0 is unlikely to be encountered.

Furthermore, small changes in coefficient values can easily result in

positive values when negative ones are intended and conversely.

It is assumed that data is put into a conic arc entity with the intent of preserving

the geometric properties of the data (major and minor semi-axes, asymptotes,

directrices, etc.) in addition to describing the points on the curve.

If the geometric properties are desired, the 104 entity should be used as described

below.

This method primarily addresses the stability problem, though the accuracy of the

conic should improve because the range of coefficient values will decrease. While

the geometric properties are not explicitly defined in this representation, they can

be obtained from it in a direct and arithmetically stable manner.

If both the sending and intended receiving system are known to use the A-F form of

the 104 entity (Conic Arc) in their own databases the preprocessor may put the data

into in the unchanged form. This minimizes the loss of information caused by

truncation and roundoff errors as no changes are made to the data. The stability

problem is presumably not of concern in this case.

479
APPENDIX E CONIC ARCS

Here is one suggested set of values:

(1) Ellipse

A :=AXISY 2 B := 0

C :=AXISX 2 D := 0

E := 0 F := -A*C

where AXISY and AXISX are the lengths of the major and minor semiaxes (not necessarily in order).

(2) Hyperbola

A := - AXISY2 (or + AXISY 2

) CD ll o C := + AXISX 2 (or - AXISX 2

, if A 0) a II o

E := 0 F := -A*C.

where AXISY and AXISX are the lengths of the major and minor semiaxes (not necessarily in order).

(3) Parabola

< n o (or 1 ) B := 0

C := 1 (or 0, if A = 1) D := 4*DIST

(or 0, if A = 1)

E := 0 (or 4*DIST, if A = 1) F := 0

where DIST is the distance of the vertex from the focus.

Preprocessor Conic Handling

The conic arc must be put into standard form, parallel to the X and/or Y axis(axes)

and centered about the origin. An 124 transformation matrix must be used to move

the conic arc into its desired position in space. In this form the coefficients in the

format that should be 0.0 will be exactly so. In particular, for the ellipse and

hyperbola B, D, and E must be 0.0, and for the parabola B and F and either A and E

or C and D must be 0.0.

Determination of the conic type from the equations becomes straight forward for the postprocessor.

For further mathematical details, see (THOM60).

480
APPENDIX F - COLOR SPACE

VARIATIONS

APPENDIX F

COLOR SPACE VARIATIONS

It is often more convenient to operate in some color space other than RGB. The

relationship between RGB and CMY is given by:

where:

R = 100.0 - C R = red C = cyan

G = 100.0 - M G = green M = magenta

B = 100.0 - Y B = blue Y = yellow

The HSL color space can be defined in terms of RGB in several ways with subtle

variations. A typical approach is given by the following transformation:

„ 1 , r 2R-G-B 1

H -TF arctan

G=B)J

S * (R 2 + G

2 + B

2 - RG - RB - BG)*5

L = (R + G + B)

where:

H = Hue

S = Saturation

L = Lightness

Variations on this transformation are given in (JOBL78) and SMIT78).

481
THIS PAGE LEFT BLANK

482
FILE CONVERSION' UTILITIES

APPENDIX G

This Appendix gives details of utility programs to convert

a file from the ASCII Form to the Compressed ASCII Form

and back again. These utilities are written in Fortran 77

code, have been tested at several sites and are available

from the IGES office at The National Bureau of Standards.

483
APPENDIX G - FILE CONVERSION

UTILITIES

APPENDIX G FILE CONVERSION

Q* **********************************************************************

C THIS PROGRAM CONVERTS BETWEEN THE IGES REGULAR ASCII FORM AND

C THE IGES COMPRESSED ASCII FORM

C THE PROGRAM IS WRITTEN IN FORTRAN 77 SOURCE.

C PROGRAM IGES

C

C PROGRAM ORIGANALLY WRITTEN BY J. M. SPAETH 7-24-84

C GENERAL ELECTRIC CORP. RE. & DEV.

C RE-WRITTEN BY LEE KLEIN 9-20-84

C GENERAL DYNAMICS CAD/CAM POMONA DIV.

C PURPOSE:

C TO CONVERT NEW FORM OF IGES OUTPUT TO OLD FORM AND

C OLD FORM TO NEW.

C

C NOTE: THIS CODE ASSUMES THAT THE ENTITY ORDER IS IDENTICAL

C IN THE DE AND PD SECTIONS OF THE OLD FORM TO BE CONVERTED

C INPUT:

C YOU MUST GIVE THE NAME INCLUDING DIRECTORY IF DIFFERENT OF

C THE FILE CONTAINING THE NEW FORM OF OUTPUT. YOU MUST ALSO

C GIVE THE NAME OF THE FILE TO CONTAIN THE CONVERTED OUTPUT.

QXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX

c CHARACTER * 80 LINE 1 CHARACTER * 60 I NFILE , OUTFILE

C

C FORMATS

C10 FORMAT($,' Enter input file name: ')

20 FORMAT($,' Enter output file name: ')

30 FORMAT ( A60

)

40 FORMAT ( A80

50 FORMAT (A)

60 FORMAT (/IX, ' *** IGES FILE CONVERSION PROGRAM ***'/)

70 FORMATC / 1 X ,' Error in filename. Try again.')

C

C PROMPT AND GET FILE NAMES...

C

GOTO 110

100 WRITE ( * , 70

)

110 WRITE ( * , 60

)

WRITEC* , 10)

READ(* ,30)INFILE

WRITEC* ,20)

READC * ,30) OUTFILE

C

C READ THE FIRST LINE. . . C

OPEN(UNIT=10 , FILE= INFILE, STATUS= 'OLD' ,ERR=100)

READC 10 ,40)LINE1

CLOSEC 10)

C

C CHECK TO SEE WHICH FORM THE INPUT IS IN...

C

IF ( LINE 1 ( 73 :73 ) • EQ .

' C

'

)

THEN

484
APPENDIX G - FILE CONVERSION

UTILITIES

CALL OLDFORM(INFILE, OUTFILE)

ELSE IF ( (LINE1 (73:73) .EQ. 'S' ) .OR.

+

+

+

(LINE1 (73:73) .EQ. ’G’ ) .OR.

(LINE1 (73:73) .EQ. ? T' ) .OR.

(LINE1 (73:73) .EQ. '§') ) THEN

CALL NEWFORMQNFILE, OUTFILE)

ELSE

WRITE(*,50)' File contains ILLEGAL record format'

CLOSE ( 10)

STOP

ENDIF

WRITE ( * , 50 ) ' ' WRITE( * , 50 )

' IGES conversion complete'

WRITE ( * ,50) ' ' END

CC

C

OLD FORM CONVERSION

SUBROUTINE OLDFORM ( INF ILE , OUTFILE

)

C

C

C

C

C

C

CC

c

c VARIABLE DECLARATIONS...

CHARACTER * 60 INFILE , OUTFILE

CHARACTER * 8 BLNK , INARR ( 20 )

, NEWARR ( 20

)

CHARACTER

485
ooo

nooo'Uiuir\)-*oon

oooooooooo

o

o

o

APPENDIX G FILE CONVERSION

UTILITIES

CALL OLDFORM( INFILE , OUTFILE)

ELSE IF ( (LINE1 (73:73) .EQ. 'S’) .OR.

+ (LINE1 (73:73) -EQ. ’G’ ) .OR.

+ (LINE1 (73:73) .EQ. 'T* ) .OR.

+ (LINE1 (73:73) .EQ. ’§') ) THEN

CALL NEWFORMUNFILE, OUTFILE)

ELSE

WRITE(* ,50) ' File contains ILLEGAL record format'

CL0SE( 10)

STOP

ENDIF

WRITE(* ,50) ' ' WRITE(*,50)' IGES conversion complete'

WRITE ( * , 50 ) ' ’ END

OLD FORM COMVERSION

SUBROUTINE OLDFORM( INFILE , OUTFILE)

PROGRAM ORIGANALLY WRITTEN BY J. M. SPAETH 7-24-84

GENERAL ELECTRIC CORP. RE. & DEV.

RE-WRITTEN BY LEE KLEIN 9-20-84

GENERAL DYNAMICS CAD/CAM POMONA DIV.

PURPOSE:

TO CONVERT NEW FORM OF IGES OUTPUT TO OLD FORM...

VARIABLE DECLARATIONS...

CHARACTER * 60 INFILE , OUTFILE

CHARACTER * 8 BLNK , INARR ( 20 ) ,NEWARR(20)

CHARACTER * 80 INLINE

CHARACTER * 1 60 OUTARR

INTEGER ICOUNT1 , ICOUNT2 , ICOUNT3 , I A , IB , IC

INTEGER I J , IK , IL , IT

DATA IPEE/1HP/

FORMATS. .

.

FORMAT ( A80

)

FORMAT (A64 , 1 18, 1A1 ,117)

FORMAT ( 1 0A8

)

FORMAT ( 9A8 , A , 17

)

F0RMAT(A8,I8,A64)

INITIALIZE OUTARR TO BLANKS...

OUTARR( 1 : 160)= ' '

OPEN INPUT AND TEMP FILES...

OPEN(UNIT=1 , FILE=' FILE 1 . TMP ' , STATU S= ' NEW ' , CARRIAGECONTROL=

LIST ' ) 0PEN(UNIT=2,FILE= ' FILE2 . TMP ' ,STATUS= 'NEW' , CARRIAGECONTROL=

LIST'

)

OPEN(UNIT=3,FILE= 'FILE3.TMP' ,STATUS= 'NEW' , CARRI AGECONTROL=

LIST ' )

486
O

O

-CTOOOOOO

-‘OOO

-»ooo

-»ooo

ooo

ooo

-»ooo

ooo

APPENDIX G - FILE CONVERSION

UTILITIES

OPEN ( UNIT=4 ,FILE=’FILE4 .TMP » ,STATUS= 1 NEW 1

, CARRIAGECONTROL= ' LIST '

)

OPEN ( UNIT=9 ,FILE=OUTFILE,STATUS= 'NEW' , CARRI AGECONTROL= • LIST •

)

OPEN (UNIT= 10, FILE= INFILE, STATUS= ’OLD’

)

INITIALIZE COUNTERS. . . IC0UNT1 = -1

IC0UNT2 = 1 IC0UNT3 = 0

READ THE FILE AND SEPARATE INTO PARTS...

0 READ( 10 , 1 ,END=600) INLINE

IF ( (INLINE(73:73) .EQ. 'S' ) .OR. ( INLINE ( 73 : 73 ) .EQ. 'G' ) ) GOTO 101

IF (INLINE(73:73) .EQ. 'T f ) GOTO 102

IF ( (INLINEC 1 : 1 ) .EQ. •§» ) .OR. (INLINEC 1 : 1 ) .EQ. * D * ) ) GOTO 400

IF IT IS AN C THAN DELETE IT OFF BE READING THE NEXT LINE

IF (INLINE(73:73) -EQ. ' C’

)

GOTO 100

PUT THE PARAMETER DATA INTO FILE4.TMP...

WRITE (4, 2) (INLINEC 1 :64) ,IC0UNTl , IPEE , ICOUNT2

)

ICOUNT2 = IC0UNT2 + 1 GOTO 100

WRITE HEADER LINES INTO FILE 1 . TMP . .

.

1 WRITEC 1, 1 ) INLINE

GOTO 100

WRITE TERMINATION LINES INTO FILE2.TMP...

2 WRITE ( 2 , 1 ) INLINE

GOTO 100

WRITE DIRECTORY ENTRY LINES INTO FILE3 . TMP . .

.

3 WRITE ( 3 > 6 ) (OUTARRC 1 :8) , IC0UNT2 , OUTARRC 17 : 80 )

)

WRITEC3.1) OUTARRC81 : 160)

ICOUNT1 = ICOUNT1 + 2

GOTO 100

REWRITE TO DE LINES IN THE NEW FORM...

GO THRU INLINE ONE CHAR. AT A TIME LOOKING FOR THE

DELIMETER (g, ,_)...

0 DO IL= 1 ,80

IF (INLINE(IL:IL) .EQ. ' ;

’ ) GOTO 103

IF (INLINE(IL:IL) .EQ. ' ') GOTO 100

IF (INLINE(IL:IL) .NE. ' g ' ) GOTO 501

DETERMINE IF THE FIELD IS ONE OR TWO CHARACTERS...

487
APPENDIX G - FILE CONVERSION

UTILITIES

C IF (INLINE(IL+2:IL+2) . EQ. ) THEN

IC=ICHAR(INLINE(IL+1 : IL+1 ) )-48

IL= IL+2

ELSE

IA=ICHAR( INLINE (IL+1 : IL+1 ) )-48

IB= ICHAR (INLINE (IL+2: IL+2) ) -48

IC= 1 0* IA+IB

IL= IL+3

ENDIF

C

C AT THIS POINT IC IS THE NUMBER OF THE RECORD FIELD BEING

C PROCESSED, AND INLINE(IL)=USCORE

C IT=0

IK = 0

IJ=(IC-1 )*8+1

C

C RESET THE FIELD TO BE CHANGED TO ALL BLANKS IN ORDER TO CREATE

C A COMPLETELY NEW FILED...

C OUTARR(IJ : IJ+7)

1 C

C WE WILL NOW CONTINUE THRU THE LINE PICKING OFF THE CHAR.

C OF THE RECORD FIELD ONE AT A TIME UNTIL A DELIMETER IS HIT...

C

450 IK= IK+

1

IF (INLINE(IL+IK:IL+IK) .EQ. ) GOTO 500

IF (INLINE(IL+IK:IL+IK) .EQ. ' ') THEN

IF (INLINE(IL+IK+1 : IL+IK+1 ) .EQ. ’ ') GOTO 500

ENDIF

IF (INLINE(IL+IK:IL+IK) .EQ. '

;

' ) GOTO 500

IT= IT+

1

IJ=(IC-1 )*8+IT

OUTARR(IJ:IJ)=INLINE(IL+IK:IL+IK)

IF (IC.EQ.1) THEN

OUTARR(IJ+80:IJ+80)=INLINE(IL+IK:IL+IK)

ENDIF

GOTO 450

500 IL= IL+IT

501 END DO

GOTO 100

C

C REWIND ALL FILES BEFORE WE WRITE THEM TO OUTPUT...

C600 REWIND 1 REWIND 2

REWIND 3

REWIND 4 C

C WRITE START AND GLOBAL RECORDS TO OUTPUT FILE...

C601 READ( 1,1, END=602) INLINE

WRITE( 9 » 1 ) INLINE

488
APPENDIX G FILE CONVERSION

UTILITIES

GOTO 601

C

C WRITE THE DE RECORDS TO OUTPUT FILE. THEY NOW BECOME RE-FORMATTED

C602 READ(3,3»END=603) (INARR(I) ,1=1 ,10)

READ(3,3) (INARR(I) ,1=1 1 ,20)

DO IP=1 ,20

IF ((IP.NE.9) .AND. (IP. NE. 18)) GOTO 200

NEWARR(IP)=INARR(IP)

GOTO 201

C

C CHANGE THOSE FIELDS THAT MUST BE RIGHT JUSTIFIED

C200 NEWARR(IP)=BLNK(INARR(IP))

201 END DO

ICOUNT3=ICOUNT3+1

WRITE (9, 5) ( ( NEWARR ( J ) ,J=1 ,9) , 'D' ,ICOUNT3)

ICOUNT3=ICOUNT3+1

WRITE (9, 5) ( ( NEWARR ( J ) ,J=11,19),'D' ,ICOUNT3)

GOTO 602

CC WRITE THE PD LINES TO THE OUTPUT FILE...

C

603 READ(4,1 ,END=604) INLINE

WRITE( 9,1) INLINE

GOTO 603

CC WRITE THE TERMINATE LINES TO THE OUTPUT FILE...

C

604 READ(2, 1 ,END=605) INLINE

WRITE ( 9 , 1 ) INLINE

GOTO 604

C

C NOW CLOSE THE FILES AND DELETE THE TEMP ONES...

C

605 CLOSE (UNIT=1 , STATUS= * DELETE 1 ) CL0SE(UNIT=2,STATUS= ' DELETE '

)

CLOSE ( UN IT= 3, STATUS=’ DELETE'

)

CL0SE(UNIT=4 ,STATUS= 1 DELETE'

)

CLOSE ( 9

)

CLOSEC 10)

RETURN

END

C START FUNCTION BLNK HERE

C

C WRITTEN BY P. R. KENNICOTT 9-29-83-

C RE-WRITTEN BY LEE KLEIN 9-2-84.

C

C PURPOSE:

C TO REMOVE BLANKS FROM END OF A CHARACTER STRING (RIGHT JUSTIFY)

C

C INPUT:

C BUF STRING WITH TRAILING BLANKS

C

489
ooooooooo

->

ooo

ooo

ooo

ooo

oooooooooooooo

APPENDIX G FILE CONVERSION

UTILITIES

OUTPUT:

BLNK STRING WITH TRAILING BLANKS REMOVED

METHOD:

FIND FIRST BLANK, THEN TRANSLATE OUTPUT STRING

RESTRICTIONS:

1 . BUF < = 512 CHARACTERS.

2. LENGTHS OF BUF & BLNK MUST BE =.

3. FIRST CHARACTER MUST NOT BE BLANK OR NO CONVERSION.

VARIABLE DECLARATIONS...

CHARACTER* ( * ) FUNCTION BLNK ( BUF)

CHARACTER* ( * ) BUF

INTEGER I CHARACTER*5 1 2 IBUF

SET UP COUNTERS. .

.

N=INDEX(BUF( 1 : )

, ’ ')-1

M=LEN ( BUF)

CHECK FOR SIZE TOO BIG. .

.

IF (M.GT.512) STOP 'Buffer too big at function BLNK'

CHECK FOR FIRST CHAR A BLANK...

IF ( BUF ( 1 : 1 ) .EQ. '

' . OR . BUF( M : M) . NE .

' ') THEN

BLNK= BUF

RETURN

ENDIF

OK PROCESS STRING. .

.

DO 10 1=1,

N

0 IBUF ( M-I+ 1 : M-I+ 1 )=BUF(N-I+1 : N-I+ 1

)

IBUF( 1 : M-N ) = ' ' BLNK= IBUF

RETURN

END

START NEW SUBROUTINE HERE

PROGRAM ORIGANALLY WRITTEN BY J. M. SPAETH 7-24-84

GENERAL ELECTRIC CORP. RE. & DEV.

RE-WRITTEN BY LEE KLEIN 9-20-84

GENERAL DYNAMICS CAD/CAM POMONA DIV.

PURPOSE:

TO CONVERT OLD FORM OF IGES OUTPUT TO NEW FORM...

SUBROUTINE NEWFORMC INFILE , OUTFILE)

C

490
APPENDIX G FILE CONVERSION

UTILITIES

C VARIABLE DECLARATIONS...

C

DIMENSION INLINEC80)

CHARACTER * 60 I NFILE , OUTFILE

DATA IPEE/1HP/

DATA IDEE/ 1 HD/

DATA ITEE/1HT/

C

C OPEN THE INPUT AND TEMP FILES...

C

OPEN ( UNIT= 1 0 ,FILE= I NFILE, STATUS= 'OLD'

)

OPEN ( UNIT= 1, FILE= ' TEST . TMP 1 , STATUS= » NEW' , CARRI AGECONTROL= ' LIST »

)

0PEN(UNIT=2,FILE= , FILE2.TMP' , STATUS= ' NEW '

)

OPEN(UNIT=3 ,FILE= *FILE3.TMP» , STATUS= ’ NEW *

)

OPEN(UNIT=7 ,FILE='FILE5.TMP' , STATUS= • NEW *

)

C

C WRITE THE HEADER WITH A "C" TO SHOW COMPRESSED ASCII FORM...

C

WRITE( 1 ,99) '

C

f 99 FORMAT ( 72X , A)

C

C SEPERATE THE PD AND DE RECORDS, WHILE WRITING G,S, &T LINES

C TO THE OUTPUT FILE. .

.

C

102 FORMAT ( 80A1

)

200 READ( 10 , 102,END=204) ( INLINE ( I ), 1= 1

, 80

)

IF (INLINE(73) .EQ.IDEE) GOTO 201

IF (INLINE(73) .EQ.IPEE) GOTO 202

IF (INLINEC73) .EQ.ITEE) GOTO 203

C

C WRITE HEADER LINES INTO A TEST. TMP...

C

WRITE (1,102) (INLINE(I) ,1=1 ,80)

GOTO 200

C

C WRITE DIRECTORY LINES INTO FILE3 • TMP . .

.

C

201 WRITE (3,102) (INLINE(I) ,1=1 ,80)

GOTO 200

C

C WRITE PARAMETER DATA INOT FILE2.TMP...

C

202 WRITE (2,102) ( INLINE ( J ), J= 1

, 80

)

GOTO 200

203 WRITE (7,102) ( INLINE( J) , J= 1 ,80)

GOTO 200

20M CALL XPD

REWIND 7

205 READ(7 , 102,END=206) ( INLINE ( I ), 1= 1 , 80

)

WRITE (1,102) (INLINE(J) ,J=1 ,80)

GOTO 205

491
OOOO

O

O

O

—'o

o

o

ooo

o

oo

->

ooooooo

ooo

APPENDIX G FILE CONVERSION

UTILITIES

206 CALL COMPRESS(OUTFILE)

CLOSE FILES AND DELETE TEMP ONES...

CLOSE (UNIT= 1

, STATUS=' DELETE'

)

CLOSE (UNIT=2,STATUS=' DELETE'

CL0SE(UNIT=3,STATUS='DELETE'

CL0SE( UNIT=4)

CLOSE (UNIT=7,STATUS=' DELETE '

)

CL0SE( UNIT= 10)

RETURN

END

SUBROUTINE XPD

PURPOSE:

TO TRANSFER ALL PD & DE RECORDS FORM TEMPORY FILES TO

OUTPUT FILE IN MERGED FORM...

VARIABLE DECLARATIONS...

CHARACTER * CHARACTER * CHARACTER * CHARACTER * INTEGER

INTEGER

FORMAT ( A80

)

1 SCOLN/ ' •

' /

8 BLNK , LSTDATC 20) ,NEWDAT(20)

80 PDLINE , DELIN 1 ,DELIN2

160 NEWDE

LFLDC20) , FLDNUM , FLDBEG , FLDEND

CHRPTR,NEWPTR, LSTPTR

REWIND THE FILES. .

.

REWIND 3 REWIND 2

INITIALIZE LAST DATA SO AS NOT OT EQUAL NEXT DATA...

LSTPTR = -1

DO FLDNUM= 1 ,20

LSTDAT ( FLDNUM) = 'XXXXXXXX'

END DO

START LOOP.. GET NEXT PD RECORD.

0 READ (2,1 ,END=120)PDLINE

CLEAR OUT THE DE RECORD BUFFER...

NEWDE (1:160) =

’ '

IF BACK-POINTER TO DE RECORD IS DIFFERENT FORM LAST PD

GET NEW DE RECORD

READ (PDLINE(65:73) ,20)NEWPTR

20 FORMAT ( 18

)

IF (NEWPTR.EQ. LSTPTR) GOTO 115

492
APPENDIX G FILE CONVERSION

UTILITIES

READ( 3 > 1 > END= 1 20 ) DELIN1

READ( 3,1) DELIN2

DELIN1 (73:73)=’ ’ DELIN2C73 :73) =

' ' CC GET THE DATA FROM EACH FIELD OF THE DE RECORD SET...

C

FLDBEG = -7

FLDEND = 1 DO FLDNUM= 1 ,10

FLDBEG=FLDBEG + 8

FLDENDrFLDEND + 8

READ(DELIN1 (FLDBEG: FLDEND) ,30) NEWDAT ( FLDNUM)

READ(DELIN2( FLDBEG: FLDEND) ,30) NEWDAT( FLDNUM+1 0)

30 FORMAT ( A8

)

END DO

C

C FIELD 18 MUST BE RIGHT JUSTIFIED...

C

NEWDAT ( 1 8 ) =BLNK( NEWDAT ( 18)

)

C

C DETERMINE THE LENGTH OF THE DATA WITHIN EACH FIELD

C

DO FLDNUM= 1 ,20

DO 1=1 ,8

IF (NEWDAT(FLDNUM) (1:1) .NE. • ») THEN

LFLD(FLDNUM)= 9-1

GOTO 40

ENDIF

END DO

40 END DO

C

C WRITE THE DE SEQUENCE NUMBER AT THE BEGINNING OF THE OUTPUT DE RECORD

C ENCODE(LFLD( 10)+1 ,60 ,NEWDE( 1 : LFLD( 1 0 ) + 1 ) ) NEWDAT ( 1 0 ) ( 9-LFLD (10) :8)

60 FORMAT ( • D

• ,A)

CHRPTR = LFLD(IO) + 2

C

C SEARCH NEW DE RECORD SET FOR CHANGED DATA; WHEN FOUNT WRITE CHANGED

C DATA TO OUTPUT DE RECORD...

C

DO FLDNUM= 1 ,20

C

C SKIP FIELDS THAT NO LONGER NEED PROCESSING...

C

IF ((FLDNUM. EQ. 2). OR.

+ (FLDNUM. EQ. 10) .OR.

+ (FLDNUM. EQ. 1 1 ) .OR.

+ (FLDNUM. EQ. 20) ) GOTO 100

IF (NEWDAT(FLDNUM) .NE.L STD AT (FLDNUM) ) THEN

IF (FLDNUM. GT. 9) THEN

ENCODE (4 ,70 , NEWDE ( CHRPTR : CHRPTR+3 ) ) FLDNUM

70 FORMAT ( ' §

1 ,12,

)

CHRPTR=CHRPTR+4

493
OOO

OOO

—

‘OOOO

^

ooo

-*

ooo

ooo

APPENDIX G FILE CONVERSION

UTILITIES

ELSE

ENCODE (3, 80 , NEWDE ( CHRPTR : CHRPTR+2 ) ) FLDNUM

80 FORMAT ('@’,11,* *)

CHRPTR=CHRPTR+3

ENDIF

IF (LFLD( FLDNUM) . NE . 0) THEN

IF (FLDNUM. NE. 9) THEN

READ( NEWDATC FLDNUM) (9-LFLDC FLDNUM) :8) ,90)

+ N EWDE (CHRPTR: CHRPTR- 1+LFLDC FLDNUM) ) 90 FORMAT ( A)

CHRPTR=CHRPTR+LFLD( FLDNUM)

ELSE

FIELD 9 IS A SPECIAL CASE...

READ( NEWDAT ( 9 ) ( 1 :8) ,90) NEWDE ( CHRPTR : CHRPTR+7 ) CHRPTR=CHRPTR+8

ENDIF

ENDIF

ENDIF

STORE DATA FORM CURRENT DE RECORD SET TO COMPARE WITH NEXT SET

LSTDAT( FLDNUM )= NEWDAT (FLDNUM)

00 END DO

NEWDE ( CHRPTR: CHRPTR) = SCOLN

IF OUTPUT DE RECORD > 80 CHAR’S, WRITE 2 LINES...

IF (CHRPTR. GT. 80) THEN

DO 1=1,11

IF (NEWDE(82-I:82-I) .EQ. ' @

’ ) GOTO 110

END DO

10 WRITE(1 ,111) NEWDE (

1

: 8 1 — I

)

11 FORMAT ( A<8 1 -I>

)

NEWDE (

1

: 80 ) =NEWDE ( 82-1 : 161-1)

ENDIF

WRITE (1,1) NEWDE (1:80)

ERASE UNNECESSARY DATA FORM PD RECORD AND WRITE TO OUTPUT FILE

THEN PURGE

15 PDLINE(65 :80)= ' ' WRITE (1 ,1) PDLINE

PDLINE ( 1:80) =

' ’

STORE CURRENT BACK-POINTER TO DE RECORD TO COMPARE WITH NEXT..

LSTPTR = NEWPTR

END OF LOOP GET NEXT PD RECORD...

GOTO 10

120 CONTINUE

999 RETURN

END

494
APPENDIX G - FILE CONVERSION

UTILITIES

C START OF SUBROUTINE COMPRESS HERE

SUBROUTINE COMP RESS ( OUTFILE

)

C

C PURPOSE:

C TO CLEAR AWAY ALL TRAILING BLANKS FROM THE OUTUT FILE

C

C VARIABLE DECLARATIONS...

C CHARACTER * 80 TEXT

CHARACTER * 60 OUTFILE

INTEGER LENGTH

C

C REWIND THE INPUT FILE AND OPEN THE OUTPUT FILE

C

REWIND 1 OPEN (UNIT=4,NAME=OUTFILE,STATUS='NEW* , CARRI AGECONTROL= * LI ST ' , + ERR= 1000)

GOTO 100

C

C GETS HERE IF THERE IS AN ERROR IN THE OUTPUT FILE NAME...

C1000 WRITE (*, 1 00 1 )' Error in OUTPUT file name. Output written to file',

+ » IGES . OUT

1001 FORMAT ( 1 X , A , A)

OPEN (UNIT=4 ,NAME= • IGES. OUT' , STATUS= * NEW ' , CARRI AG EC0NTR0L=’ LIST*

)

C

C READ RECORD LINES INTO BUFER ONE AT A TIME...

C

100 READ( 1 ,30,END=400) TEXT

30 FORMAT ( A80

)

LENGTH = 80

C

C GO THRU EACH LINE DELETEING TRAILING BLANKS

C

200 IF ( TEXT( LENGTH : LENGTH ) .NE. ’ ') GOTO 300

LENGTH= LENGTH1

IF (LENGTH. GT. 1 ) GOTO 200

C

C WRITE PROCESSED LINES TO THE OUTPUT FILE

C300 WRITE ( 4 , 40 ) TEXT ( 1 : LENGTH

)

40 FORMAT (A<LENGTH>)

C

GOTO 100

C

400 CONTINUE

RETURN

END

495
THIS PAGE LEFT BLANK

496
LIST OF REFERENCES

ANSI68

ANSI74

ANSI77

ANSI78

ANSI79

BLOM82

COON67

DEB078

DOD12D

DOCA76

FAUX79

GORD 74

HILD76

IEEE260

IEEE85

IITR68

JOBL78

LIST OF REFERENCES

American National Standards Institute, Code for Information Interchange

(X3.4- 1968), ANSI, 1968.

American National Standards Institute, Code Extension Techniques for Use

with the 7-Bit Coded Character Set of American National Standard Code for

Information Interchange (ASCII), X3.4-1968 (X3.4 1-1974), ANSI, 1974.

American National Standards Institute, Code for Information Interchange

(X3.4-1977), ANSI, 1977.

American National Standards Institute, Line Conventions and Lettering

(Y 14.2-1979), ANSI, 1978.

American National Standards Institute, FORTRAN (X3. 9-1978), ANSI, 1978.

Blomgren, R. and R. Fuhr, Algorithms to Convert Between Rational B-spline

and Rational Bezier Representations of Curves and Surfaces, National Bureau

of Standards, 1982.

Coons, S. A., Surfaces for Computer Aided Design of Space Forms , MIT

Project MAC TR-41, June 1967.

deBoor, C., A Practical Guide to Splines , Springer-Verlag, 1978.

Department of Defense, Abbreviations for Use on Drawing, Specifications,

Standards, and in Technical Documents (MIL-STD-12D).

DoCarmo, M. P., Differential Geometry of Curves and Surfaces, Prentice Hall,

1976.

Faux, I., and M. J. Pratt, Computational Geometry for Design and

Manufacture, John Wiley and Sons, 1979.

Gordon, W. J. and R. F. Riesenfeld, "B-Spline Curves and Surfaces", published

in Barnhill, R. E. and R. F. Riesenfeld, ed., Computer Aided Geometric

Design, Academic Press, 1974.

Hildebrand, F., Advanced Calculus for Applications , Prentice Hall, 1976.

Institute of Electrical and Electronics Engineers, IEEE Standard Letter

Symbols for Units of Measurement (ANSI/IEEE Std 260), IEEE.

Institute of Electrical and Electronics Engineers, Standard for Binary FloatingPoint Arithmetic (ANSI/IEEE Std 754-1985), IEEE, 1985.

Illinois Institute of Technology Research Institute, APT Computer System

Manual: Volume 2 - Subroutine Library , IITRI, 1968.

Joblove, G. H. and D. Greenberg, Color Spaces for Computer Graphics, SIGGRAPH Proceedings, 1978.

497
LIST OF REFERENCES

KAPL52

ROGE76

SMIT78

THOM60

Kaplan, W., Advanced Calculus, Addison-Wesley, 1952.

Rogers, D. F. and 3. A. Adams, Mathematical Elements for Computer

Graphics, McGraw-Hill, 1976.

Smith, A. R., Color Gamut Transformation Pairs , Computer Graphics, 1978.

Thomas, G., Calculus and Analytic Geometry, Addison-Wesley, 1960.

498
GLOSSARY

IGES GLOSSARY

The spirit of this Glossary is to provide general, sometimes intuitive information

pertaining to certain phrases and concepts either appearing in or alluded to by this

document. The spirit is not to provide detailed mathematical definitions such as may be

found within the document itself. ANGULAR DIMENSION ENTITY

An annotation entity designating the measurement of the angle between two

geometric lines. ANNOTATION

Text or symbols, not part of the geometric model, which provide information.

ASSEMBLY (IEEE 200-1975)

A number of basic parts or subassemblies, or any combination thereof, joined

together to perform a specific function.

ASSOCIATIVITY

A structure entity, which defines a logical link or relationship between different

entities.

ASSOCIATIVITY DEFINITION ENTITY

A structure entity which designates the type (link structure) and generic meaning of a relationship. (See PRE-DEFINED ASSOCIATIVITIES)

ASSOCIATIVITY INSTANCE ENTITY

A structure entity formed by assigning specific values to the data items defining an

associativity.

ATTRIBUTE

Information, provided in specific fields within the directory entry of an entity,

which serves to qualify the entity definition.

AXONOMETRIC PROJECTION

A projection in which only one plane is used, the object being turned so that three

faces show. The main axonometric positions are isometric, dimetric, and trimetric.

BACK POINTER

A pointer in the parameter data section of an entity pointing to an associativity

instance of which it is a member.

BASIC PART (IEEE 200-1975)

One piece, or two or more pieces joined together, which are not normally subject to disassembly without destruction of designed use.

499
GLOSSARY

BLANK STATUS FLAG

A portion of the status number field of the directory entry of an entity designating

whether a data item is to be displayed on the output device.

BOUNDED PLANE

A finite region defined in a plane.

BREAKPOINT

A member of an increasing sequence of real numbers which is a subsequence of the

knot sequence used to specify parametric spline curves.

B-SPLINE BASIS

A set of functions which form a basis for the set of splines of specified degree on a

specified knot sequence. B-spline basis functions are characterized by being splines

of minimal support. See appendix A4 for more details.

CENTERLINE ENTITY

An annotation entity for representing the axis of symmetry for all symmetric views

or portions of views, such as the axis of a cylinder or a cone. CIRCULAR ARC ENTITY

A geometric entity which is a connected portion of a circle or the entire circle.

CLASS

A group of data items pertinent to a common logical relationship in an associativity

definition.

CLIP

To abbreviate or terminate the intended display of an entity along an intersecting curve or surface.

CLIPPING BOX

A bounding set of surfaces which abbreviate the intended display of data to that

portion which lies within the box.

CLIPPING PLANE

A bounding plane surface which abbreviates the intended display of data to that

portion which lies on one or the other side of the plane.

CLOSED CURVE

A curve with coincident start and terminate points.

500
GLOSSARY

COMPLEMENTARY ARC

Either of the two connected components of a closed connected curve which has been

divided by two distinct points lying on the curve. COMPONENT

Typically a synonym for part (e.g., resistor, capacitor, microcircuit, etc.), but also

may refer to a subassembly being treated as a part. The IGES representation of a component may be a collection of entities, associativities, and properties.

COMPOSITE CURVE

A connected curve which is formed by concatenating two or more curve segments.

CONIC ARC ENTITY

A geometric entity which is a finite connected portion of an ellipse, a parabola, or a

hyperbola.

CONNECTED CURVE

A curve such that for any two points PI and P2, one can travel from PI to P2

without leaving the curve. CONNECTION POINT ENTITY

A geometric entity giving the XYZ location and other information (e.g., text labels)

of a point of connection. May be independent or subordinate to a Network subfigure

definition and/or instance. Used for netlist information.

CONSTITUENT

A member of a set. CONTROL POINT

A point in definition space which appears in the numerator of the expression for a

rational B-spline curve or surface. If the weights are all positive, the resulting curve or surface lies within the convex hull of the control points. Its shape

resembles that of the polygon or polyhedron whose vertices are the control points.

A control point is sometimes referred to as a B-spline coefficient. See appendices

A4 and A6 for more details.

COONS PATCH

A three dimensional surface.

COPIOUS DATA ENTITY

A geometric entity sometimes used as an annotation entity, containing arrays of

types of real numbers to which a specific meaning has been assigned. One form

number corresponds to one special meaning.

501
GLOSSARY

DEFINITION LEVEL (or DISPLAY LEVEL)

The graphics display level (or layer) on which one or more entities have been

defined.

DEFINITION MATRIX

The matrix which transforms the coordinates represented in the definition space

into the coordinates represented in the model space.

DEFINITION SPACE

A local Cartesian coordinate system chosen to represent a geometric entity for the

purpose of mathematical simplicity.

DEFINITION SPACE SCALE

A scale factor applied within an entity definition space.

DEVELOPABLE SURFACE

A surface which can be unrolled onto a plane.

DIAMETER DIMENSION ENTITY

An annotation entity designating the measurement of a diameter of a circular arc. DIRECTED CURVE

A curve with an associated direction derived from the start and terminate points.

DIRECTORY ENTRY SECTION

The section of an IGES file, consisting of fixed field data items for an index and

attribute list of all entities in the file. DIRECTRIX

The curve entity used in the definition of a tabulated cylinder entity.

DISPLAY SYMBOL

A method for graphically representing certain entities (plane, point, section) for

identification purposes.

DRAWING ENTITY

A structure entity which specifies the projection(s) of a model onto a plane, with

any required annotation and/or dimension.

DRILLED HOLE PROPERTY

A predefined property that assigns the physical attribute of a hole that can be made

502
GLOSSARY

by a drill. May be used in electrical applications to 1) define a via from one printed

circuit board, PCB, layer to another, 2) define a plated via hole, and 3) give the first physical drill diameter and/or the finished hole diameters. It is usually attached to a point, circle, subfigure definition or instance.

EDGE VERTEX

A method of geometric modeling in which a two- or three-dimensional object is represented by curve segments (edges of the object) connected to points or vertices

of the object. A higher level of topological information can be contained in such a model than is implied by a 'wire-frame' terminology, but in the context of this

specification the terms are used interchangeably.

ENTITY

The basic unit of information in a file. The term applies to single items which may

be individual elements of geometry, collections of annotation to form dimensions, or collections of entities to form structured entities.

ENTITY LABEL

A one to eight character identifier for an entity. This term may implicitly include

the entity subscript, providing for additional characters.

ENTITY SUBSCRIPT

A one to eight digit unsigned integer associated with the entity label. The label and

subscript specify a unique instance of an entity within an array of entities.

ENTITY TYPE NUMBER

An integer used to specify the kind of the entity. For example, the circular arc

entity has an entity type number of 100.

ENTITY USE FLAG

A portion of the status number field of the directory entry of an entity to designate

whether the entity is used as geometry, annotation, structure, logical, or other. For

example, a circle used as part of a point dimension would have an entity use flag

which designates annotation.

EXTERNAL REFERENCE ENTITY

A mechanism for referencing definitions which do not reside in the same IGES file as the instances of those definitions.

FINITE ELEMENT

A small part of a structure defined by the connection of nodes, material, and

physical properties.

FLAG NOTE ENTITY

An annotation entity which takes label information and formats it such that the text

is circumscribed by a flag symbol.

503
GLOSSARY

FLASH

The Flash entity may be used to represent a repetitive artwork feature which is usually produced by photo-optical means. Examples include PC pads, targets,

clearances and IC features.

FLASH ENTITY

A geometric entity used for photo-plotting apertures and other filled areas. May be

used for representing metallic conductive material on a printed circuit board such as pads and traces. Also, may be used in integrated circuit, IC, chip masks.

FLEXIBLE PRINTED CIRCUIT

An arrangement of printed circuit and components utilizing flexible base materials

with or without flexible cover layers.

FLOW ASSOCIATIVITY ENTITY

A predefined associativity that represents a flow path. In electrical applications

such as schematics and physical descriptions for Printed Wiring Boards, PWB,

Printed Circuit Boards, PCB, PCB assemblies, ICs, etc., it presents a common

electrical signal (e.g., voltage). In piping applications it represents a flow path

between only one source and sink, but branching is allowed to other Flow

Associativities. It provides netlist information for a single flow.

FONT CHARACTERISTIC

An integer which is used to identify a text font. Font characteristic numbers may

be positive which indicate an IGES-defined text font or may be negative which is interpreted as a text font definition entity.

FORM NUMBER

An integer which is used when needed to further define a specific entity. This

becomes necessary when there are several interpretations of an entity type. For

example, the form number of the conic arc entity indicates whether the curve is an

ellipse, hyperbola, parabola, or unspecified. The form number is also used when

necessary to supply sufficient information in the directory entry of an entity to allow the structure of the parameters in the parameter data entry to be decoded.

GENERAL LABEL ENTITY

An annotation entity consisting of a general note with one or more associated

leaders.

GENERAL NOTE ENTITY

An annotation which consists of text which is to be displayed in some specific size

and at some specific location and orientation.

GENERATRIX

The defining curve which is to be swept to generate a tabulated cylinder, or revolved to generate a surface of revolution.

504
GLOSSARY

GEOMETRIC

Having to do with the shape information (points, curves, surfaces, and volumes),

necessary to represent some object.

GLOBAL SECTION

The section of an IGES file consisting of general information describing the file, the

file generator (pre-processor), and information needed by the file reader (postprocessor).

GRID

The set of (ui, vj) where ui and vj are the breakpoints on the u and v coordinates

respectively used to specify a parametric spline or rational B-spline surface. The

term grid is also applied to the projected image on the spline surface.

GROUND PLANE

A conductor layer, or portion of a conductor layer (usually a continuous sheet of

metal with suitable clearances), used as a common reference point for circuit

returns, shieldings, or heat sinking.

GROUP ASSOCIATIVITY

A predefined associativity for forming any collection of entities.

HIERARCHY

A tree structure consisting of a root and one or more dependents. In general, the

root may have any number of dependents, each of which may have any number of

lower-level dependents, and so on, to any number of levels.

INSTANCE

A particular occurrance of some item or relationship. Several instances may

reference the same item.

KNOT SEQUENCE

A nondecreasing sequence of real numbers used to specify parametric spline curves. LABEL DISPLAY ASSOCIATIVITY

A pre-defined associativity that is used by those entities that have one or more

possible displays for their entity label. Entities requiring this associativity will have

pointers in their directory entry to a label display associativity instance entity

LEADER ENTITY

An annotation entity, also referred to as arrow, which consists of an arrowhead and one or more line segments. In the case of an angular dimension entity, the line

segment is replaced by a circular arc segment. In general, these entities are used in connection with other annotation entities to link text with some location.

505
GLOSSARY

LEVEL

An entity attribute which defines a graphic display level to be associated with the

entity.

LEVEL FUNCTION PROPERTY

A predefined property that assigns an "application data base defined functionality" to a level. This property may stand alone (e.g., DE status is independent), that is no

other entity points to it. Also, see the level field in directory entry.

LINE ENTITY

A geometric entity consisting of a straight segment connecting two points in space.

LINE FONT

A pattern for the appearance of a curve. The pattern is a repeating sequence of

blanked and unblanked line segments, or of subfigure instances.

LINE FONT DEFINITION ENTITY

A structure entity which defines a line font.

LINE WEIGHT

An entity attribute which is used^to determine the line display thickness for that

entity.

LINE WIDENING PROPERTY

A predefined property that overrides the line weight given in the directory entry of an entity by providing a physical value for the actual width. May be used in electrical applications to describe metallization on a printed circuit board such as traces and off board connections. Also, see the FLASH and SECTION entities and

the Region Fill property.

LINEAR DIMENSION ENTITY

An annotation entity used to represent a distance between two locations.

LINEAR PATH ENTITY

A geometric entity that defines a collection of linear segments that form a path.

Also, see Copious Data Entity Forms 11 and 12. MACRO BODY

The portion of a macro definition containing statements which define the action of

the macro. MACRO DEFINITION ENTITY

The structure entity, containing the macro body within its parameter data section,

used to define a specific macro.

506
GLOSSARY

MACRO INSTANCE ENTITY

A structure entity which will invoke a macro which has been defined using a macro

definition entity.

MIRROR

To reflect through an axis.

MODEL

A particular collection of data in an IGES file which describes a product.

MODEL SPACE

A right-handed three-dimensional Cartesian coordinate space in which the product is represented.

NEGATIVE BOUNDED PLANAR PORTION

A hole.

NETWORK SUBFIGURE DEFINITION ENTITY

A structure entity used to define a schematic symbol, component or pipe in electrical and piping applications. Shall be used whenever associated Connect Point

Entities need to be instanced with the Network Subfigure Instance Entity. For

physical components it may have subordinate entities (copious data, simple closed

area, subfigure definition or instance, etc.) that have attached a Region Restriction

Property giving design rules for auto routing a Printed Circuit Board, PCB. Also, 2-

D component outlines and 3-D phsical descriptions may be defined.

NETWORK SUBFIGURE INSTANCE ENTITY

A structure entity used to specify an occurrence of a schematic symbol, component

or pipe in electrical and piping applications. It has associated "instanced" Connect

Point Entities that give the XYZ model space point of connections. Used in netlist

information and part lists. NODAL DISPLACEMENT and ROTATIONAL ENTITY

This entity is used to communicate finite element post processing data. It contains

the node identifier, original node coordinates, and incremental displacements and

rotations for each node for each load case. NODAL LOAD/CONSTRAINT ENTITY

An entity used in a finite element model to apply a force, moment, or other loading

or constraints at a specific node.

NODE

A point in space used to define a finite element topology.

507
GLOSSARY

ORDINATE DIMENSION ENTITY

An annotation entity used to indicate dimensions from a common reference line in the direction of the XT or YT axis.

ORTHONORMAL

A term describing two vectors which are orthogonal and of unit length.

PARAMETER DATA SECTION

A section of an IGES file consisting of specific geometric or annotative information

about the entities or pointers to related entities.

PARAMETRIC SPLINE CURVE ENTITY

A geometric entity consisting of polynomial segments subject to certain continuity

conditions.

PARAMETRIC SPLINE SURFACE ENTITY

A geometric entity which is a smooth surface made from a grid of patches. The

patches are regions between the component parametric curves. PARENT CURVE

The full curve on which a segment curve lies. PART NUMBER PROPERTY

A predefined property that provides one or more text strings giving one to four

distinct part numbers (Generic, MIL-STD, Vendor, and/or Internal) to an entity

representing a physical part. May be used in electrical, piping or other applications.

Usually, it is attached to a subfigure definition and/or instance that represents the

part. May be used for part lists. PATCH

A surface represented by parametric functions of two parameters which blend four

given boundary curves.

PIN NUMBER PROPERTY

A predefined property that provides a text string giving a component pin number

value to an entity representing an electrical component. Also, see the CONNECT

POINT Entity.

PLANE ENTITY

A geometric entity which is a surface with the property that the straight line passing through any two distinct points on the surface lies entirely on the surface.

PLATED-THROUGH HOLE (ANSI/IPC-T-50B)

A hole in which electrical connection is made between internal or external

conductive patterns, or both, by the deposition of metal on the wall of the hole.

508
GLOSSARY

POINT ENTITY

A geometric entity which has no size but possesses a location in space.

POINT DIMENSION ENTITY

An annotation entity consisting of a leader, text, and an optional circle or hexagon

enclosing the text. POINTER

A number that indicates the location of an entity within an IGES file.

POSITIVE BOUNDED PLANAR PORTION

The top of a peg.

POST-PROCESSOR

A program which translates a file of product definition data from the form of this

standard into the data base form of a specific CAD/CAM system.

PRE-DEFINED ASSOCIATIVITIES

Associativities which are defined within this standard.

PRE-PROCESSOR

A program which translates a file oY product defintiion data from the data base

form of a specific CAD/CAM system into the form of this standard.

PRINTED BOARD (ANSI/I PC-T-50B)

The general term for completely processed printed circuit or printed wiring

configurations. It includes rigid or flexible, single, double, or multilayer boards.

PRINTED CIRCUIT (ANSI/IPC-T-50B)

A conductive pattern comprised of printed components, printed wiring, or a combination thereof, all formed in a predetermined design and intended to be

attached to a common base. (In addition, this is a generic term used to describe a

printed board produced by any of a number of techniques.)

PRINTED CIRCUIT BOARD (ANSI/IPC-T-50B)

A part manufactured from rigid base material upon which a completely processed

printed circuit has been formed.

PRINTED WIRING (ANSI/IPC-T-50B)

The conductive pattern intended to be formed on a common base, to provide pointto-point connection of discrete components, but not to contain printed components.

509
GLOSSARY

PRODUCT DEFINITION

Data required to describe and communicate the characteristics of physical objects

as manufactured products.

PROPERTY ENTITY

A structure entity which allows numeric or text information to be related to other

entities.

RADIUS DIMENSION ENTITY

An annotation entity which is a measurement of the radius of a circuiar arc. RATIONAL B-SPLINE CURVE

A parametric curve which is expressed as the ratio of two linear combinations of Bspline basis functions. Each basis function in the numerator is multiplied by a scalar

weight and a vector B-spline coefficient. Each corresponding basis function in the

denominator is just multiplied by the corresponding weight.

RATIONAL B-SPLINE SURFACE

A parametric surface which is expressed as the ratio of two linear combinations of

products of pairs of B-spline basis functions. Each product of basis functions in the

numerator is multiplied by a scalar weight and a vector B-spline coefficient. Each

corresponding product of basis functions in the denominator is multiplied by the

corresponding weight.

REFERENCE DESIGNATOR PROPERTY

A predefined property that provides a text string giving a component reference

designator value to an entity representing an electrical component. Also, see the

Network Subfigure entity.

REGION

The bounded area enclosed by a closed curve or a combination of curves. REGION FILL PROPERTY

A predefined property that is used to solid fill or unfill (nested) a closed area. May

be used for cross-section material representations (i.e., concrete, steel, etc.) and

artwork. Also, see the SECTION entity. Also, see the FLASH and SECTION entities

and the Line Widening property.

REGION RESTRICTION PROPERTY

A predefined property that provides design rules in electrical applications.

Especially, region restrictions regarding Printed Circuit Board, PCB routing rules

for prohibiting or permitting vias and traces under component outlines and

placement of components on the printed circuit board.

510
glossary

RELATION

An aspect or quality that connects two or more things or parts as being or belonging

or working together or as being of the same kind.

REPEATING PATTERN

An ordered sequence of items (elements) which, after a certain point, repeats itself. RIGHT-HANDED CARTESIAN COORDINATE SYSTEM

A coordinate system in which the axes are mutually perpendicular and are positioned

in such a way that, when viewed along the positive Z axis toward the origin, the

positive X axis can be made to coincide with the positive Y axis by rotating the X

axis 90 degrees in the counterclockwise direction.

RULED SURFACE ENTITY

A surface generated by connecting corresponding points on two space curves by a

set of lines. SECTION ENTITY

A pattern used to distinguish a closed region in a diagram. It is represented as a form of the copious data entity.

SECTION DISPLAY SYMBOL

An arrangement of fonted straight lines in a repetitive planar pattern at a specified

spacing and angle.

SET (IEEE 200-1975)

A unit or units and necessary assemblies, subassemblies, and basic parts connected

or associated together to perform an operational function.

SIMPLE CLOSED AREA ENTITY

A geometric entity used to give a 2-D mathematically simple closed area (no holes

or boundary intersections). See Copious Data entity Form 63. May be used for

electrical design rules in conjunction with the Region Restriction property.

SINGLE PARENT ASSOCIATIVITY ENTITY

A predefined associativity that provides logical grouping of a single parent entity to

its many children entities.

SPLINE

A piecewise continuous polynomial.

START SECTION

The section of an IGES file containing a man-readable file prolog.

511
GLOSSARY

SUBASSEMBLY (IEEE 200-1975)

Two or more basic parts which form a portion of an assembly or a unit, replaceable

as a whole, but having a part or parts which are individually replaceable.

SUBFIGURE DEFINITION ENTITY

A structure entity which permits a single definition of a detail to be utilized in multiple instances.

SUBFIGURE INSTANCE ENTITY

A structure entity which specifies an occurrence of the subfigure definition.

SUBORDINATE ENTITY SWITCH

A portion of the status number field of the directory entry of an entity. An entity is subordinate if it is an element of a geometric or annotative entity structure or is a member of a logical relationship structure. The terms subordinate and dependent

are equivalent within this document.

SURFACE OF REVOLUTION ENTITY

A geometric entity which is a surface generated by rotating a curve, called the

generatrix, about an axis, called the axis of rotation.

SYSTEM (IEEE 200-1975)

A combination of two or more sets, generally physically separated when in operation, and other such units, assemblies, and basic parts necessary to perform an

operational function or functions.

TABULAR DATA PROPERTY

The tabular data property provides a structure to accommodate point form data.

The basic structure is a two-dimensional array containing data list for depenent and

independent variable.

TABULATED CYLINDER ENTITY

A geometric entity which is a surface generated by moving a line parallel to itself along a space curve called the generatrix.

TERMINATE SECTION

The final section of an IGES file, indicating the sizes of each of the preceding file sections.

TEXT DISPLAY TEMPLATE ENTITY

An annotation entity used to define the display location of a text string. In electrical applications it gives a "relative" mode of location dependent on a connect

point for pin number and/or pin function of components (e.g., Integrated Circuit, 1C,

chip pins). For electrical schematic symbols and physical components it may give

the display location of the reference designator text and/or part number.

512
GLOSSARY

TEXT FONT

The specification of the appearance of the characters.

TEXT FONT DEFINITION ENTITY

The entity used to define the appearance of characters in a text font. A character

is defined by pairing its character code with a sequence of display strokes and

positional information.

TRANSFORMATION MATRIX ENTITY

An entity which allows translation and rotation to be applied to other entities. This

is used to define alternate coordinate systems for definition and viewing

TRANSLATION VECTOR

A three element vector which specifies the offsets (along the coordinate axes)

required to move an entity linearly in space.

UNIT (IEEE 200-1975)

A major building block for a set or system, consisting of a combination of basic

parts, subassemblies, and assemblies packaged together as a physically independent

entity.

VERSION NUMBER

A means for uniquely designating one specification definition or translator

implementation from a preceding or subsequent one.

VIA HOLE (ANSI/IPC-T-5QB)

A plated-through hole used as a through connection, but in which there is no

intention to insert a component lead or other reinforcing material.

VIEW ENTITY

A structure entity used to provide the definition of a human-readable representation

of a two-dimensional projection of a selected subset of the model and/or non- geometry information.

VIEWING BOX

The clipping box used to define a view.

WEIGHT

A non-zero real number which appears in the numerator and denominator of the

expression for a rational B-spline curve or surface. Increasing the weight associated

with a particular control point will tend to draw the resulting curve or surface

toward that control point. See appendices A4 and A6 for details.

513
GLOSSARY

WIRE-FRAME

A method of geometric modeling in which a two- or three-dimensional object is represented by curve segments which are edges of the object. In the context of this

specification, 'wire-frame' and 'edge-vertex' models are considered as the same

technique and the terms are used interchangeably.

WITNESS LINE

An annotation entity consisting of line segments and used in engineering drawings to indicate the beginning or the end of a measurement.

514
INDEX OF TOPICS

Page(s) ANGULAR DIMENSION ENTITY 209

ANNOTATION 1 ANNOTATION ENTITIES 206

ANGULAR DIMENSION 209

CENTERLINE 213

DIAMETER DIMENSION 215

FLAG NOTE 217

GENERAL LABEL 221

GENERAL NOTE 223

LEADER (ARROW) 238

LINEAR DIMENSION 243

ORDINATE DIMENSION 245

POINT DIMENSION 247

RADIUS DIMENSION 249

SECTION 251

GENERAL SYMBOL 254

SECTIONED AREA 122, 256

WITNESS LINE 259

ARC CENTER POINT 215, 249

ARC LENGTH 146

ARROWHEAD TYPE 238

ASCII 9

ASSOCIATIVITY 6, 264

CONNECT NODE 301

ENTITY LABEL DISPLAY 275

EXTERNAL REFERENCE FILE INDEX 90, 269

DIMENSIONED GEOMETRY 282

FLOW 289

GROUP 266

GROUP WITHOUT BACK POINTERS 278

ORDERED GROUP 285, 286

PLANAR 287

PRE-DEFINED 266

SIGNAL STRING 297

SINGLE PARENT 279

TEXT NODE 299

VIEW LIST 296

VIEWS VISIBLE 6, 270

VIEWS VISIBLE, PEN, LINE WEIGHT 272

ASSOCIATIVITY DEFINITION ENTITY 262

ASSOCIATIVITY INSTANCE ENTITY 264

ASSOCIATIVITY SCHEMA 262

ATTRIBUTE 4 ATTRIBUTES, DIRECTORY ENTRY

BLANK STATUS 31

COLOR NUMBER 37

ENTITY LABEL 37

ENTITY SUBSCRIPT NUMBER 38

ENTITY TYPE NUMBER 30, 36

ENTITY USE FLAG 34

515
FORM NUMBER

HIERARCHY 35

LABEL DISPLAY ASSOCIATIVITY POINTER 31

LEVEL NUMBER 30

LINE FONT PATTERN NUMBER 30

LINE WEIGHT 36

PARAMETER DATA POINTER 30

PARAMETER LINE COUNT NUMBER 37

SEQUENCE NUMBER 9, 36, 38

STATUS NUMBER 31

STRUCTURE POINTER 30

SUBORDINATE ENTITY SWITCH 31

TRANSFORMATION MATRIX POINTER 31 VIEW POINTER 30

B-SPLINE 469

BACK POINTER 262

BICUBIC POLYNOMIAL 138

BINARY REPRESENTATION 9, 63

DIRECTORY ENTRY SECTION 78

GLOBAL SECTION 75

PARAMETER SECTION 80

START SECTION 75

TERMINATE SECTION 82

BLANK STATUS 31 BOUNDED PLANE 126

BREAKPOINTS 132, 469

CENTERLINE ENTITY 122,213

CHARACTER APPEARANCE 223, 405

CIRCULAR ARC ENTITY 108, 170

CIRCULAR ARRAY SUBFIGURE INSTANCE ENTITY 401

CLASSES 108

CLIPPING 305,413

CLIPPING BOX 414

COLOR NUMBER 37

COMPOSITE CURVE ENTITY 1 1

1

CONE 173

CONIC ARC ENTITY 116

CONNECT NODE ASSOCIATIVITY 301

CONNECTIVITY 85, 88

CONSTANTS 10 INTEGER 11 LANGUAGE STATEMENT 13 POINTER 13 REAL 13 STRING 13 CONSTITUENT ENTITY 1 1

1

CONTINUITY 132

516
CONTROL POINTS FOR B-SPLINE 472

COONS' PATCH 475

COORDINATE SYSTEM 104, 158, 411

COPIOUS DATA ENTITY 122

CUBIC SPLINE 132, 470

CURVE ON A PARAMETRIC SURFACE ENTITY 198

CYLINDER 173

DATA FORM 9

DEFINITION 104

DEFINITION LEVEL 6, 345

DEFINITION SPACE 104, 158, 207

DEGREE OF CONTINUITY 132, 472

DEPTH 207

DEVELOPABLE SURFACE 147

DIAMETER DIMENSION ENTITY 215

DIMENSIONED GEOMETRY ASSOCIATIVITY 282

DIMENSIONS

ANGULAR DIMENSION ENTITY 209

DIAMETER DIMENSION ENTITY 215

LINEAR DIMENSION ENTITY 243

ORDINATE DIMENSION ENTITY 245

POINT DIMENSION ENTITY 247

RADIUS DIMENSION ENTITY 249

DIRECTED CURVE 106

DIRECTRIX 155

DIRECTORY ENTRY SECTION 25

DISPLAY SYMBOL 126

DRAWING ENTITY 6, 303

DRAWING SIZE PROPERTY 392

DRAWING UNITS PROPERTY 393

DRILLED HOLE PROPERTY 351

DUMMY POLYNOMIAL SEGMENT 133

EDGE-VERTEX 1 ELECTRICAL EXAMPLE 425

ELEMENT TOPOLOGY 186

ELLIPSE 116, 170, 478

ENCODED FILES (EXAMPLES) 425, 465

ENTITY

ANGULAR DIMENSION 209

ASSOCIATIVITY DEFINITION 262

ASSOCIATIVITY INSTANCE 264

CENTERLINE 122, 213

CIRCULAR ARC 108

CIRCULAR ARRAY SUBFIGURE INSTANCE 401

COMPOSITE CURVE 111

CONIC ARC 116

COPIOUS DATA 122

CURVE ON A PARAMETRIC SURFACE 198

DIAMETER DIMENSION 215

DRAWING 6, 303

EXTERNAL REFERENCE 90,417

FINITE ELEMENT ENTITY 95, 184

FLAG NOTE 217

517
FLASH 167

GENERAL LABEL 221

GENERAL NOTE 223

LEADER (ARROW) 238

LINE 130

LINE FONT DEFINITION 308

LINEAR DIMENSION 243

MACRO DEFINITION 321

MACRO INSTANCE 334

NETWORK SUBFIGURE INSTANCE 403

NODE 98, 181

NODAL DISPLACEMENT AND ROTATION 192

NODAL LOAD/CONSTRAINT 419

OFFSET CURVE 176

OFFSET SURFACE 195

ORDINATE DIMENSION 245

PARAMETRIC SPLINE CURVE 132

PARAMETRIC SPLINE SURFACE 138

PLANE 126

POINT DIMENSION 247

POINT 144

PROPERTY 344

RADIUS DIMENSION 249

RATIONAL B-SPLINE CURVE 169

RATIONAL B-SPLINE SURFACE 172

RECTANGULAR ARRAY SUBFIGURE INSTANCE ENTITY 397

RULED SURFACE 146

SECTION 251

SECTIONED AREA 256

SUBFIGURE DEFINITION 394

SUBFIGURE INSTANCE 397

SURFACE OF REVOLUTION 151

TABULATED CYLINDER 155

TRIMMED (PARAMETRIC) SURFACE 201

TEXT FONT DEFINITION 405

TRANSFORMATION MATRIX 7, 98, 158

VIEW 6,411

WITNESS LINE 259

ENTITY LABEL 37

ENTITY LABEL DISPLAY ASSOCIATIVITY 275

ENTITY SUBSCRIPT NUMBER 38

ENTITY TYPE NUMBER 30,36

ENTITY USE FLAG 34

EXTERNAL REFERENCE ENTITY 90,417

EXTERNAL REFERENCE FILE INDEX ASSOCIATIVITY 90, 269

EXTERNAL REFERENCE FILE LIST PROPERTY 388

FILE STRUCTURE 9

DIRECTORY ENTRY SECTION 25

GLOBAL SECTION 18 PARAMETER SECTION 55

START SECTION 16 TERMINATE SECTION 58

FINITE ELEMENT ENTITIES 95

NODE ENTITY 95,181

ELEMENT ENTITY 95, 184

518
MATERIAL PROPERTIES (TABULAR DATA) 356

NODAL LOAD/CONSTRAINTS

NODAL DISPLACEMENT AND ROTATIONS

FLAG NOTE ENTITY

FLASH ENTITY

FLOW ASSOCIATIVITY

FLOW LINE SPECIFICATION PROPERTY

FONT CHARACTERISTIC

FONT NUMBER

FORM NUMBER

FREE FORMAT

419

192

217

167

289

390

223

223

37

14 GENERAL LABEL ENTITY

GENERAL NOTE ENTITY

GENERATRIX

GEOMETRIC

GEOMETRY

221

223

151, 155

1 CIRCULAR ARC

COMPOSITE CURVE

CONIC ARC

COPIOUS DATA

LINE

OFFSET CURVE

OFFSET SURFACE

PARAMETRIC SPLINE CURVE

PARAMETRIC SPLINE SURFACE

PLANE

POINT

RATIONAL B-SPLINE CURVE

RATIONAL B-SPLINE SURFACE

RULED SURFACE

SURFACE OF REVOLUTION

TABULATED CYLINDER

TRANSFORMATION MATRIX

GLOBAL SECTION

GROUP ASSOCIATIVITY

108

111

116

122

130

176

195

132

138

126

144

169

172

146

151

155

7, 98, 158

18

6, 266, 278, 285, 286

HIERARCHY

HIERARCHY PROPERTY

HYPERBOLA

35

355

117, 170, 478

INTEGER CONSTANT 11 KNOT SEQUENCE FOR B-SPLINE 469

LABEL DISPLAY ASSOCIATIVITY

LABEL DISPLAY ASSOCIATIVITY POINTER

LANGUAGE STATEMENT CONSTANT

LEADER (ARROW) ENTITY

LEVEL

LEVEL FUNCTION PROPERTY

LEVEL NUMBER

LINE ENTITY

275

31

13

223

30, 345, 347

347

30

130

519
LINE FONT DEFINITION ENTITY 170, 308

LINE FONT PATTERN NUMBER 30

LINE REMOVAL 6

LINE WEIGHT NUMBER 23, 36

LINE WIDENING PROPERTY 349

LINEAR DIMENSION ENTITY 243

LINEAR SPLINE 133

MACRO

ATTRIBUTES 314

CAPABILITY SECTION 314

DEFINITION ENTITY 321

EXAMPLES 335

INSTANCE ENTITY 334

SYNTAX 315

MACRO DEFINITION ENTITY 321

MACRO INSTANCE ENTITY 334

MATERIAL PROPERTIES

BEAM ELEMENT END RELEASES 376

BENDING COUPLING MATERIAL STIFFNESS MATRIX 369

BENDING MATERIAL STIFFNESS MATRIX 367

CONVECTIVE FILM COEFFICIENT 385

ELECTROMAGNETIC RADIATION PARAMETERS 385

ELEMENT THICKNESS 380

HEAT CAPACITY 384

LAMINATE MATERIAL STIFFNESS MATRIX 366

MATERIAL COORDINATE SYSTEM 371

MATERIAL MATRIX 363

MASS DENSITY 364

NODAL LOAD/CONSTRAINT DATA 374

NON-STRUCTURAL MASS 381

OFFSETS 377

POISSON'S RATIO 361

SECTION PROPERTIES FOR BEAM ELEMENTS 375

SHEAR MODULUS 362

STRESS RECOVERY INFORMATION 378

THERMAL CONDUCTIVITY 382

THERMAL EXPANSION COEFFICIENT 364

TRANSVERSE SHEAR MATERIAL STIFFNESS MATRIX 368

YOUNG'S MODULUS 360

MIRROR FLAG 223

MODEL 5 MODEL SPACE 104, 158, 207

MODIFIED WILSON-FOWLER SPLINE 133, 470

NAME PROPERTY 391

NETWORK SUBFIGURE DEFINITION ENTITY 395

NETWORK SUBFIGURE INSTANCE ENTITY 403

NODE ENTITY 95,181

NODAL DISPLACEMENT AND ROTATION ENTITY 192

NODAL LOAD/CONSTRAINT ENTITY 419

NOMINAL SIZE PROPERTY 389

520
NON-GEOMETRY

OBSOLETE ASSOCIATIVITY ENTITIES

OFFSET CURVE ENTITY

OFFSET SURFACE ENTITY

ORDERED GROUP ASSOCIATIVITY

ORDINATE DIMENSION ENTITY

ORGANIZATION

ORIENTATION

205

295

176

195

285, 286

2454.2.12

16

PARABOLA

PARAMETER DATA POINTER

PARAMETER DATA SECTION

PARAMETER LINE COUNT NUMBER

PARAMETRIC PIECEWISE CUBIC POLYNOMIAL CURVE

PARAMETRIC SPLINE CURVE ENTITY

PARAMETRIC SPLINE SURFACE ENTITY

PART NUMBER PROPERTY

PIN NUMBER PROPERTY

PLANAR ASSOCIATIVITY

PLANE ENTITY

POINT DIMENSION ENTITY

POINT ENTITY

POINTER CONSTANT

PRE-DEFINED ASSOCIATIVITIES

PRODUCT DEFINITION

PROPERTY

117, 170, 478

30

55

37

469

132

138

354

353

287

126, 173

247

144

13 266

1,2

DEFINITION LEVELS

DRAWING SIZE

DRAWING UNITS

DRILLED HOLE

EXTERNAL REFERENCE FILE INDEX

FLOWLINE SPECIFICATION

HIERARCHY

LEVEL FUNCTION

LINE WIDENING

NAME

NOMINAL SIZE

PART NUMBER

PIN NUMBER

REFERENCE DESIGNATOR

REGION FILL

REGION RESTRICTION

TABULAR DATA

PROPERTY ENTITY

345

392

393

351

388

390

355

347

349

391

389

354

353

352

348

346

356

344

QUADRATIC SPLINE 133

RADIUS DIMENSION ENTITY

RATIONAL B-SPLINE CURVE ENTITY

RATIONAL B-SPLINE SURFACE ENTITY

REAL CONSTANT

RECTANGULAR ARRAY SUBFIGURE INSTANCE ENTITY

REFERENCE DESIGNATOR PROPERTY

249

169

172

13

397

352

521
REGION FILL PROPERTY 348

REGION RESTRICTION PROPERTY 346

ROTATION 7 ROTATION MATRIX 98,158

RULED SURFACE ENTITY 146, 173

SECTION ENTITY

SECTIONED AREA ENTITY

SEQUENCE NUMBER

SEXTUPLES

SINGLE PARENT ASSOCIATIVITY

SLANT ANGLE

SPHERE

SPLINE CURVE

SPLINE REPRESENTATION

SPLINE SURFACE

START ANGLE

START SECTION

STATUS NUMBER

STRING CONSTANT

STRUCTURE ENTITIES

ASSOCIATIVITY DEFINITION ENTITY

ASSOCIATIVITY INSTANCE ENTITY

EXTERNAL REFERENCE ENTITY

EXTERNAL REFERENCE FILE INDEX ASSOCIATIVITY

EXTERNAL REFERENCE FILE LIST PROPERTY

GROUP ASSOCIATIVITY ENTITY

LINE FONT DEFINITION

MACRO DEFINITION ENTITY

MACRO INSTANCE ENTITY

PRE-DEFINED ASSOCIATIVITIES

PROPERTY ENTITY

SUBFIGURE DEFINITION ENTITY

SUBFIGURE INSTANCE ENTITY

TEXT FONT DEFINITION ENTITY

VIEW ENTITY

VIEW LIST ASSOCIATIVITY

VIEWS VISIBLE

VIEWS VISIBLE, PEN, LINE WEIGHT ASSOCIATIVITY

STRUCTURE POINTER

STRUCTURES

SUBFIGURE DEFINITION ENTITY

SUBFIGURE INSTANCE ENTITY

SUBORDINATE ENTITY SWITCH

SURFACE OF REVOLUTION ENTITY

SURFACES

OFFSET SURFACE

PARAMETRIC SPLINE SURFACE ENTITY

RATIONAL B-SPLINE SURFACE ENTITY

RULED SURFACE ENTITY

SURFACE OF REVOLUTION ENTITY

TABULATED CYLINDER ENTITY

251

122, 256

9, 36, 38

122

279

227

173

132, 469

132, 470

138, 470

151

16

31

13

262

264

90, 417

90, 269

388

266, 278, 285, 286

308

321

334

266

344

394

397

405

6, 411

296

270

272

30

85

394

397

31

151, 173

195

138

172

146

151

155

522
TABULAR DATA PROPERTY 356

TABULATED CYLINDER ENTITY 155, 173

TERMINATE ANGLE 151

TERMINATE SECTION 58

TEXT BOX 227

TEXT FONT DEFINITION ENTITY 405

TORUS 173

TRANSFORMATION MATRIX POINTER 31

TRANSFORMATION MATRIX ENTITY 7, 98, 158

TRANSLATION 7, 103

TRANSLATION VECTOR 104

TRIMMED (PARAMETRIC) SURFACE ENTITY 201

TRIPLES 122

UNBOUNDED PLANE 126

VERTEX POINT 209

VIEW ENTITY 6,411

VIEW LIST ASSOCIATIVITY 296

VIEW POINTER 30

VIEWPORT 303, 411

VIEWING DIRECTION 411

VIEWS VISIBLE ASSOCIATIVITY 270

VIEWS VISIBLE, PEN, LINE WEIGHT ASSOCIATIVITY 272

WILSON-FOWLER SPLINE 133, 470

WIRE-FRAME 7 WITNESS LINE ENTITY 259

ZT DISPLACEMENT 207

»U.S. GOVERNMENT PRINTING OFFICEl 1986 0-691-097/52529

523



HB5-114A <«ev. s«c»

U.S. DEPT. OP COMM.

BIBLIOGRAPHIC DATA

SHEET (See Instructions)

1. PUBLICATION OR

REPORT NO.

NBSIR 86-3359

2. Performing Organ. Report No, 1. Publication Date

April 1986

4. TITLE AND SUBTITLE

Initial Graphics Exchange Specification (IGES) Version 3.0

S.

(»UTHCA(S)

Smith, B., Briggs, D., Colsher, R., Kennicott, P., Parks, C . , Wellington, J.

i. 5 ERf-ORMING ORGANIZATION (If joint or other than NBS. see Instructions) 7. Contract/Grant No.

NATIONAL bureau of standards

DEPARTMENT OF COMMERCE

WASHINGTON, D.C. 21234

1. Type of Report & Period Covered

Jan 1983 - Dec 1985

8. SPONSORING ORGANIZATION NAME AND COMPLETE ADDRESS (Street. City. Stote, ZIP

)

10. SUPPLEMENTARY NOTES

| ~| Document describes computer procram; SF-185, FIPS Software Summary, Is attached.

11. ABSTRACT (A 200-word or less factual summary of most significant information. If document includes a significant

bibliography or literature survey. mention It here)

This document contains Version 3.0 of the Initial Graphics Exchange Specification,

a defined format for the creation of a file which enables data found in today*

s

commercially available CAD/CAM systems to be “exchanged or archived.

IGES, Version 1.0, published as NBSIR 80-1978 (R) in January 1980, consisted of

entity definitions for geometry, drafting and structural information. Definition

entities were provided as a means of expanding the utility of IGES.

Version 3.0 further refines the concept and offers increased capability in both

geometry and non-geometry data exchange. The applications of printed wiring boards

and finite element models are well supported in addition to enhancements for

mechanical products.

12. KEY WORDS (Si* to twelve entries; alphabetical order; capitalize only proper names; and separate key words by semicolons

)

Computer Aided Design (CAD), Computer Aided Manufacturing (CAM), design drawing,

electrical Information, exchange format, finite element modeling, geometries,

graphics.

13. AVAILABILITY 14. NO. OF

PyI Unlimited

PRINTED PAGES

1 1 For Official Distribution. Do Not Release to NTIS 523

l~Vl Order From Superintendent of Documents, U.S. Government Printing Office, Washington, D.C.

20402. IS. Price

I~x~l Order From National Technical Information Service (NTIS). Springfield, VA. 22161 $40.95

UlCOMM-DC •04*-*,

0