HDTenEightyP/NetNews huggingface dataset:
From: Alastair_McColl@mindlink.bc.ca (Alastair McColl)
Subject: Re: 3d graphics for c
Organization: MIND LINK! - British Columbia, Canada
Date: Tue, 17 Nov 1992 20:06:48 GMT

Hi
> jason ang writes:
>
> Msg-ID: <1992Nov14.4387.19860@dosgate>
> Posted: 14 Nov 92 23:40:51 EST
>
> Org.  : Canada Remote Systems
>
>         I'm looking for algorithms to plot a 3d object on a 2d screen
>         and to rotate/translate/scale it.  Could someone please send me
>         some info or recommend some books about this?  I'm fairly new to
>         computer graphic programming.

You might try "Supercharged C++ graphics" by Lee Adams,
Windcrest/McGraw-Hill. It has a good set of listings for 3d routines for
several different compilers. It's not blowing my sox off, but seems like a
good starting point.


--
Alastair McColl, Bird's Eye PMSB
------------------------------------------------------------- email:
a2111@mindlink.bc.ca  | "GRAVITY: NOT JUST A GOOD IDEA,
tel/fax: (604)873-8434       |            IT'S THE LAW"
Newsgroups: comp.graphics
From: orourke@sophia.smith.edu (Joseph O'Rourke)
Subject: Re: Point inside a triangle
Organization: Smith College, Northampton, MA, US
Date: Tue, 17 Nov 1992 03:30:31 GMT

In article <1e9k0cINNc0q@uniwa.uwa.edu.au> watson@maths.uwa.oz.au (David Watson) writes:

>and if b0 == 0 => (x1 == x2 && x1 == x3 && y1 == y2 && y1 == y3)

I think you meant to say if b0 == 0, then the three triangle vertices
are collinear: the above implication is too strong.
From: buc5045@cuphub.cup.edu
Newsgroups: comp.graphics
Subject: help with graphics in comp. games
Date: 21 Nov 92 02:01:00 GMT
Organization: California University of Pennsylvania, California, PA

Does anyone know what books I can reference in order to animate figures?

Actually, what I am asking is:

I am trying to write a computer role-playing game and I need information as how
to do the animation that would be requirred in such a task.

I am writing the game using "C".  Any help would be aprreciated.

I do understand that some of the still pictures in these games are paintings
that have been scanned into the source program.  I would also aprreciate any
help in this area as well.


STRYFE

David B. Bucco
Cal. U. of PA
Applied Comp. Sci.

Actually, I have been trying to create a computer role-
Xref: sparky comp.graphics:11991 ont.events:559
Newsgroups: comp.graphics,ont.events,ut.dcs.graphics
From: mccool@dgp.toronto.edu (Michael McCool)
Subject: Toronto Siggraph, Nov 17, CANCELLATION
Organization: University of Toronto Dynamic Graphics Project
Distribution: ont
Date: 17 Nov 92 22:01:38 GMT

ACM Toronto Siggraph
====================

The talk "Realistic Dinosaur Animation" by Geoff Davidson for tonight,
Nov 17, has been cancelled.  Our speaker has fallen ill.

Due to the late notice we have had no time to schedule an alternate
event, and apologize for the late posting which most likely will reach
very few of you.

The event will probably be rescheduled for December 15.
-- 
=====================================================================
Michael McCool (mccool@dgp.toronto.edu or mccool@dgp.utoronto.ca)   
Dynamic Graphics Project, University of Toronto, Canada
From: djjames@cup.portal.com (Daniel J James)
Newsgroups: comp.graphics
Subject: Re: contouring (ie. topographic) code?
Date: Fri, 20 Nov 92 14:51:23 PST
Organization: The Portal System (TM)

>Hi,
>
>    Does anyone know of any public domain code (preferably in C) which
>will generate a contour plot from gridded data?
>
>Thanks, John M. Troiano
>        Lehigh Univ.
>
>        
The June or July 92 issue of Dr. Dobbs Journal has some C source code
that does an exellant job.

Djj
From: aron@samarra.ced.berkeley.edu (aron bonar)
Newsgroups: comp.graphics
Subject: Re: Problems with 3D studio-NOW Hi-color flic
Date: 17 Nov 1992 04:35:47 GMT
Organization: University of California, Berkeley
Distribution: world
NNTP-Posting-Host: samarra.ced.berkeley.edu

In article <1992Nov16.152424.1@ualr.edu>, djlewis@ualr.edu writes:
|> In article <1992Nov16.102830.1@tnclus.tele.nokia.fi>, lauusitalo@tnclus.tele.nokia.fi writes:

|> 	One other problem I encountered was makeing a hi_colour .FLI . I tried
|> rendering in targa and tiff modes, this creates individual frame files, but I
|> could'nt re-assemble them into a movie without conversion back to 256 colour.
|> Has anyone done a hi-colour or truecolor movie to disk?
|> 
|> later, Don
|> 

The only Hi-Color Animation player I've seen is called HCFLI. It does 32000 color animations at 
640x480.

Location:  bode.ee.ualberta.ca  /incoming   hcfli05.zip and hcplay07.zip

Comments: Reads 16/24/32 bit TGA files and put them together into a hicolor animation.
          Shareware is limited to 25 frames or less.

	I've had some problems with it playing animations made up of dithered images. 
        Well actually, I can't get them to play at all. :-)
       
        To be more precise...I put together a series of 24 bit TGAs straight from 3d Studio. That
	worked fine....but I had some pretty bad color banding...yes even at 32k colors
	So I put the images through DTA (another shareware animation/image processing program) and 
	dithered them to get rid of the banding. I remade the flic with the dithered images but I           can't play it.  I always get a memory error and my system crashes.

	But I'm still trying...

Aron
Newsgroups: comp.graphics
From: steve@fulcrum.oz.au (Steve Taylor)
Subject: Re: VOGL vs. VOGLE
Organization: The Fulcrum Consulting Group
Date: Mon, 23 Nov 1992 03:24:25 GMT

reznick@acf3.nyu.edu (Daniel Reznick) writes:

>What are the differences between VOGL and VOGLE?

>I know that VOGL is meant to be a subset of the normal GL, but beyond
>this, is one of the two (VOGL/VOGLE) more complete, function wise?
>Does one perform better than another?
VOGLE is their main program,and gets more work done on it. VOGL gets a bit
less atention, so if you want functionality, not compatibility, I'd suggest
VOGLE. (And while you're at it, pick up VORT, their raytracer. Free pepsi
with every order.)


								Steve
From: pfuetz@igd.fhg.de (Matthias Pfuetzner)
Newsgroups: comp.graphics
Subject: Re: Porting Sun PHIGS programs using NURBS
Date: 17 Nov 92 09:20:06 GMT
Reply-To: pfuetz@igd.fhg.de (Matthias Pfuetzner)
Organization: Zentrum fuer Graphische Datenverarbeitung, Darmstadt, FRG
Phone: +49 6151 155-150
Room: B 013
Operating-System: SunOS 4.1.2
Machine-Type: sun4c
Machine-Name: sokrates

Hello Neil!

Both your e-mail addresses (neil@yc.estec.nl,neil@gec-erc.co.uk) aren't valid!
So I reply in this newsgroup!

In article <1992Nov10.183112.17144@yc.estec.esa.nl> you write:
>    We currently have a large program that makes extensive use of NURBS
>surfaces using Sun PHIGS.  Is there anyone out there who has any information 
>on porting something like this to other platforms and/or PHIGS packages.

I've been using SunPHIGS, X11R5 libphigs.a (which was written by Sun and is a
subset of SunPHIGS, but produces PEX (PHIGS Extension to X) protocol calls.
This implies that you need an X-Server which is capable of PEX) and graPHIGS,
the PHIGS library of IBM. The NURBS shall be no problem when using the Sun
based products (e.g. SunPHIGS and the libphigs.a which comes with X11R5 from
MIT). Furthermore the NURBS shall be no problem when using graPHIGS on the
console a potent IBM RS/6000 (potent meaning one of the upper end graphics
adapters). If displayed to a dump X-terminal you will only see a wireframe
model of the NURBS, so no shading, lighting will be possible.

For references I include a part of my code (if #ifdefs etc.)
   Pfloat_list       uknots;
   Pfloat_list       vknots;
   Ppoint_grid34     grid;

   /* Apply the weights */
#ifndef USE_GRAPHIGS
   for( ii = 0 ; ii < ii_end ; ++ii )
   {
      grid.points.point4d[ii].x *= grid.points.point4d[ii].w;
      grid.points.point4d[ii].y *= grid.points.point4d[ii].w;
      grid.points.point4d[ii].z *= grid.points.point4d[ii].w;
   }
#endif

#if defined( AIXV3 ) && defined( USE_GRAPHIGS )
   GPNBS( (Pint)2, (Pint) 3, uknots.num_floats - 2, vknots.num_floats - 3,
          uknots.floats, vknots.floats, 0, 0, 0, 1, 4, grid.points.point4d,
          uknots.floats[0], uknots.floats[uknots.num_floats - 1],
          vknots.floats[0], vknots.floats[vknots.num_floats - 1] );
#else
   pnuni_bsp_surf( (Pint)2, (Pint)3, &uknots, &vknots, PRATIONAL, &grid,
                   (Pint) 0, (Ptrimcurve_list *) 0 );
#endif

I haven't been using any other PHIGS, so I can't tell you anything about it.

Hoping having helped a bit,
Sincerly,
        Matthias

P.S.: If you have questions, ask me!
-- 
    Matthias Pfuetzner  |  @work:  +49 6151 155-150  | @home: +49 6151 75717
    6100 Darmstadt, FRG | ZGDV, Wilhelminenstrasse 7 | Lichtenbergstrasse 73
      pfuetzner@igd.fhg.de, pfuetzner@zgdvda.UUCP    |  Keith Packard said:
      R5 is different from R4. That's why we changed the release number :-)
Newsgroups: comp.graphics
From: chris@stellacom.com (Chris Cressy)
Subject: Re: Orchid Faren. 1280 good? bad? what?
Organization: StellaCom, Inc., Arlington, VA
Date: Fri, 20 Nov 1992 15:03:14 GMT

In article <1992Nov18.213128.20615@wam.umd.edu> ara@wam.umd.edu (Ara Kotchian) 
writes:

>We are about to buy a 486 system with a NEC 5FG monitor
>the Graphics card the company we are buying from is a
>Orchid Fahrenheit 1280, 
>do any of you have any experience with this card?
>can it do 1280 by 1024 resolution, is it backwardly
>compatible with all the other resolutions?
>What problems, if any, have you had with it,

I've got a Northgate 486 EISA with a NEC 4FG and the Orchid Farhrenheit 1280
that I've had for about 9 months now.  I've been using it exclusively in
windows so I can't comment on the other display drivers.  The Orchid card 
is working great with the latest windows drivers (Version 2.1).  I did have
some problems with earlier drivers though -- fonts would sometimes get
ratty looking in MS Word.  

I've been using it at the 1024x768 res with 256 colors.  I've seen a few
minor artifacts in displaying images.  For example, when displaying a gray-
scale image in MS Word or Paintbrush it will sometimes show some color.
Apparently, its matching an image gray color to the non-gray-color in 
its default color map with similar intensity.  Overall, though it works 
well and is quite fast for the word processing and light desktop publising
I use it for.

I'm not sure, but I think you get only 16 colors using 1280x1024 res.

Hope this helps,
Chris
-- 
--------------------------------------------------------------------
Chris Cressy           StellaCom, Inc. / Advanced Television Systems
chris@stellacom.com    1901 N. Moore St., Suite 601
(703) 243-1695         Rosslyn, VA  22209
Newsgroups: comp.graphics
From: scott@statsci.com (Scott Blachowicz)
Subject: Re: CGM standard, how to obtain
Reply-To: scott@statsci.com
Organization: Statistical Sciences, Inc., Seattle, WA USA
Distribution: usa
Date: Thu, 19 Nov 1992 22:00:39 GMT

>>>>> "Bob" == Bob Hirsch <hirsch@pioneer.arc.nasa.gov>

 Bob> As a followup to a recent thread on the CGM (Computer Graphics Metafile)
 Bob> standard:

 Bob> It is now ISO/IEC 8632-1 (1992), previously ANSI X3.122 - 1986.  The
 Bob> content is the same.
      ...
 Bob> The document costs $145.00.

I just called ANSI and got a price of $65 for ISO 8632-4 (1992), or at least I
think that's what he said. Any idea what the difference between "-1" and "-4"
is?

On a related note, does anyone know where one might find some source code that
generates CGM output, and some sample CGM output. The idea being to acquire
enough information to figure out how to generate CGM out of code that I might
write. Or should the standards document do that?

Thanx,
--
Scott Blachowicz    Ph: 206/283-8802x240      USPS:  Statistical Sciences, Inc
                                                      1700 Westlake Ave N #500
scott@statsci.com / uunet!statsci!scott                Seattle, WA USA   98109
..or..     Scott.Blachowicz@seaslug.org
Newsgroups: comp.graphics
From: mclemore@rebec.asd.contel.com (Ken McLemore)
Subject: NAPLPS converted software or users
Keywords: NAPLPS
Reply-To: mclemore@rebec.asd.contel.com (Ken McLemore)
Organization: CONTEL Federal Systems
Date: Fri, 20 Nov 1992 13:52:15 GMT

looking for users of the ansi standard NAPLPS image format,
North American Presentation Level Protocol Syntax.  we're
trying to find/write software to convert other image formats
(ex. gif, tiff, cgm ...) to naplps.
any info or direction to another group appreciated.
thanks in advance, ken
Newsgroups: comp.graphics,comp.graphics.animation
From: streit@iam.unibe.ch (Christoph Streit)
Subject: graphtal 1.0 available again!
Reply-To: streit@iam.unibe.ch
Organization: Dept. of Computer Science, University of Berne, Switzerland
Date: Fri, 20 Nov 1992 14:05:29 GMT


The L-system interpreter graphtal 1.0 is available 
again via anonymous FTP at iamsun.unibe.ch (130.92.64.10) and 
is found as /Graphics/graphtal-1.0.tar.Z or 
/Graphics/graphtal_no_bison_no_flex-1.0.tar.Z.

______________________________________________________________

Sorry for the inconvenience, but we had to remove graphtal
from our FTP server for the following reason:

Jonathan P. Leech (leech@cs.unc.edu) blamed me for not including
references to his L-system package 'lsys'. There's no excuse for
my behaviour. Anyhow, I'd like to apologize for misusing Jon 
Leech's effort in that way and I hope that he is satisfied with 
the references added. Please look at the README file for more 
details.
______________________________________________________________


graphtal is an L-system interpreter and is e.g. useful for the
following tasks:

o generation of geometric objects like trees, plants, 
  skyscrapers, ...
o you can produce different kinds of output including 
  output for rayshade, X11 or ppm (portable pixmap).
o you can use the models produced by graphtal in your own images.
o you can compute animations with graphtal (refer to the examples).
o some example L-system descriptions are included (birchtree, 
  firtree, a plant, ...) to start with.

Features of graphtal:

o  D0L-systems,
o  tables of productions,
o  productions with parameters,
o  stochastically applied productions,
o  global and local constants,
o  hull definitions (turtle interpretation with regard to
   these hulls),
o  production parameters may be strings or real values,
o  animations support,
o  turtle interpreter with macros,
o  preview for X11,
o  Z-buffer preview and output for rayshade.

What you will need:

- C++ compiler 
- bison and flex (if not available get graphtal_no_bison_no_flex.tar.Z)
- rayshade 4.0.6 and the URT toolkit (necessary for the rayshade driver)

Supported platforms:

- Sun SparcStations with Sun C++ 2.1, Sun C++ 3.0, AT&T 2.0, AT&T 3.0
  and g++ 2.2.2
- IBM RS/6000 with AT&T C++ 2.0
- DEC Station with DEC C++ 1.0 or g++

Examples:

In the directory graphtal/Examples some interesting L-systems are 
included. The animation scripts will need nawk or gawk in order
to work.

Please send bugs (accompanied by L-systems causing them),
interesting L-systems for inclusion in the release, enhancements,
and suggestions to the author via email.

Christoph Streit (streit@iam.unibe.ch)
From: cplai@csie.nctu.edu.tw
Newsgroups: comp.graphics
Subject: Virtual Reality, info need
Date: 22 Nov 92 14:14:07 GMT
Organization: Dep. Computer Science & Engin. of Chiao Tung Univ., Taiwan, ROC


Hi:
   We would like to start doing research on Virtual Reality. We need any kind
of info, especially in Software, Hardware, Paper, Codes, ......
   Any info will be appreciated.

 Please reply to :cplai@ccsun5.csie.nctu.edu.tw

 Thanks in advance.

Scott
.
Newsgroups: comp.graphics
From: comp.graphics
Subject: Bitmap compress algorithm/code
Organization: Woods Hole Oceanographic Institution
Date: Thu, 19 Nov 92 14:26:12 GMT


I am looking for compression algorithms/code for bitmaps.
Much the same as used in FAX machines.  Anyone know of a source.

Thanks in advance.

-- 
| w   ww   w  hh  hh  oooooo iiiiii | Robert L. Eastwood        |	      
| ww  ww  ww  hhhhhh  oo  oo   ii   | Ocean Engineer            |
|  w w  w w   hhhhhh  oo  oo   ii   | Woods Hole Oceanographic  |
|   ww  ww    hh  hh  oooooo iiiiii | Woods Hole, MA  02546     |
From: dennisp@kpc.com (Dennis Preston)
Subject: Re: Turning Indigo monitor off when unused
Organization: Kubota Pacific Computer Inc, Santa Clara, CA
Date: Fri, 20 Nov 1992 23:29:38 GMT

In article <DAVIS.92Nov20133925@nod.bms.com> davis@nod.bms.com (Malcolm Davis) writes:
>
>In defence of Dale Atems original question about powering off the
>monitor and to counter Jim McNicholas and Todd Scalzott's cute
>comebacks, I would point out that when we first got our Ardent at the
>University of Houston leaving the monitor turned off would crash the
>system!
>
Hey!!! Why you pickin' on Titans. I've got one at home! (above comment was true
though) ;^>
>Malcolm Davis / davis@nod.bms.com / BMSPRI Princeton, NJ
>
>--
>Malcolm E. Davis
>
>USMail: Macromolecular Modeling
>        Bristol-Myers Squibb
>	P.O.Box 4000
>        Princeton, NJ 08530-4000
>Email : davis@nod.bms.com
>Phone : 609-252-4324
>FAX   : 609-252-6030
>Office: LV H.3812


Xref: sparky comp.graphics:12136 comp.lang.c:16862
From: ccspad@sunlab1.bath.ac.uk (Paul Dale)
Newsgroups: comp.graphics,comp.lang.c
Subject: Re: Please Help Me Keep My Job!
Date: 20 Nov 92 11:51:08 GMT
Organization: University of Bath, England

Could the originator of the thread send me some personnel
forms from his company, I'd like to work there. I'm not too
hot on programming but I'd like to try out my script writing :-),
it was Satire and Vitriol Inc. wasn't it ?

Paul
Systems admin./applications support/programmer.
BUCS, Bath University, Claverton Down, Bath, Avon. UK BA2 7AY
tel: 0225 826215
e-mail: P.A.Dale@bath.ac.uk
fax: 0225 826176
Xref: sparky comp.graphics:12090 alt.graphics:416 comp.sys.mac.apps:17404 comp.sys.mac.wanted:10739
From: jeanthea@oasys.dt.navy.mil (Mark Jeantheau)
Newsgroups: comp.graphics,alt.graphics,comp.sys.mac.apps,comp.sys.mac.wanted
Subject: Macintosh draw question
Date: 19 Nov 92 17:32:41 GMT
Reply-To: jeanthea@oasys.dt.navy.mil (Mark Jeantheau)
Followup-To: comp.graphics
Organization: Carderock Division, NSWC, Bethesda, MD

I'm looking for a Macintosh drawing program that will let me draw stylized 
graphics like those seen in USA Today graphs.  I want to do it as objects (as 
opposed to bitmaps) to get 300-dpi resolution.  Most programs have a "freehand" 
tool that will allow a Bezier shape to be constructed and filled.  However, 
it's very difficult to get smooth curves when drawing freehand.  As an 
alternative approach, I tried drawing and reshaping arcs and straight lines to 
create the outline, which worked quite well; but when I try to fill, it fills 
the individual arcs, which look like pie slices, and the whole thing is a mess. 
(This is true even if I group the objects together before filling.)

I've tried various approaches in MacDraw Pro and Superpaint 3.0; I've also 
taken a quick look at Illustrator 3.0.  None of these seems to provide a simple 
solution for creating Postscript shapes (lines, arcs, freehands) linked 
together to compose one filled shape. Any ideas?

PLEASE E-MAIL.  Thanks.
-----
jeanthea@oasys.dt.navy.mil // Mark Jeantheau // (202) 227-3562 // U.S. Navy
Naval Surface Warfare Center, Carderock Div. // Code 1401 // Bethesda MD 20084
-----
Opinions expressed herein blah blah blah... [Standard disclaimer.]
-----
Newsgroups: comp.graphics
From: dutko@sysmgt.enet.dec.com (Nestor Dutko)
Subject: Re: Orchid Faren. 1280 good? bad? what?
Organization: Digital Equipment Corporation
Date: Thu, 19 Nov 1992 16:41:13 GMT

In article <69831@cup.portal.com>, Don_-_Hirschfeld@cup.portal.com writes...
>The are better and cheaper Windows acelerator cards out here. In non windows
>mode, the card is actually slower than some super VGA cards. Get a Diamond 
>Speedstar24X with is much faster in both modes and can display 16.7 mill
>colors at 640x480.

  Yes, but what refresh rates does it support at 1280x1024? Hopefully its
  better than what the Speedstar24x supports.


Nestor Dutko			dutko@star.enet.dec.com
VMS Development			decwrl!star.dec.com!dutko
Digital Equipment Corp	
110 Spit Brook Road ZK03-2/Y05, Nashua NH 03063
Opinions expressed are not that of DEC...
Newsgroups: comp.graphics,comp.sys.sgi,comp.unix.misc,comp.unix.questions,rec.humor
From: davis@nod.bms.com (Malcolm Davis)
Subject: Re: Turning Indigo monitor off when unused
Organization: Bristol-Myers Squibb, Macromolecular Modeling
Date: Fri, 20 Nov 1992 18:39:25 GMT


In defence of Dale Atems original question about powering off the
monitor and to counter Jim McNicholas and Todd Scalzott's cute
comebacks, I would point out that when we first got our Ardent at the
University of Houston leaving the monitor turned off would crash the
system!

Malcolm Davis / davis@nod.bms.com / BMSPRI Princeton, NJ

--
Malcolm E. Davis

USMail: Macromolecular Modeling
        Bristol-Myers Squibb
	P.O.Box 4000
        Princeton, NJ 08530-4000
Email : davis@nod.bms.com
Phone : 609-252-4324
FAX   : 609-252-6030
Office: LV H.3812
From: kawai@kwlab.osakac.ac.jp (Toshiyuki KAWAI)
Newsgroups: comp.graphics
Subject: Re: Meta Balls
Keywords: meta balls, blob, implicit surface, soft object
Date: 18 Nov 92 08:23:45 GMT
Organization: Osaka Electro-Communication Univ., Japan

In article <BxGJC4.11B.1@cs.cmu.edu>, ph+@cs.cmu.edu (Paul Heckbert) writes:
> Shortly thereafter, people at Osaka University and at Toyo Links in Japan
> began using blobby models also.  They called theirs "metaballs"

> I don't know of any papers by the Japanese on their blobby modeling
> work, which is too bad, because they have probably pushed the technique
> further than anyone.

Several years ago, when I was a graduate student, once we tried 
to submit a English one, but ...

Here is a Japanese one:
H. Nishimura, M. Hirai, T. Kawai, T. Kawata, I. Shirakawa and K. Omura, 
"Object Modeling by Distribution Function and a Method of Image Generation",
Trans. IECE Japan part D, Vol.J68-D, No.4, pp.718-725, 1985.

--
Toshiyuki Kawai (kawai@kwlab.osakac.ac.jp)
Osaka Electro-Communication Univ.
18-8 Hatsu-cho, Neyagawa, Osaka, 572 Japan
Phone:+81-720-24-1131 ext.4560   Fax:+81-720-24-0014
From: kiki@bass.bu.edu (Keith Baccki)
Newsgroups: comp.graphics
Subject: Re: Point inside a triangle
Date: 16 Nov 92 01:42:31 GMT
Reply-To: kiki@bass.bu.edu (Keith Baccki)
Followup-To: comp.graphics
Organization: Boston University

In article <7bv1svg@rpi.edu> bohn@rdrc.rpi.edu writes:
>
>Does anyone have any suggestions on how to check if a point is located
>inside a triangle, accurately and fast.


	The method I used as part of a line clipping algorithm for
clipping lines to an arbitrary triangle is as follows:

	- Select a point known to be inside the triangle
	
		x = (v1.x + v2.x + v3.x)/3
		y = (v1.y + v2.y + v3.y)/3

	- Now draw a line from that point to the point in question
	  and perform a line intersection test with each edge of
	  the triangle. NOTE: You must only accept intersections 
	  within the extents of the line *segments* in question,
	  NOT the whole lines.


	i.e.       /\ C
		  /  \        Line AB intersects edge C, but segment
                 /A. .\       AB doesn't -> Extent test on both segments
                /____B_\      shows that the point of intersection is
                              within C, but not segment AB.

	- If there are no segment intersections, the line is inside.

	- Whether the line is on a triangle edge or not can be 
	  decided with more code.


Criticisms? Alternatively, you could go the inward normal route as
you've pointed out, but I thought this method was a little less dep-
endent on the manner in which you define your triangle edges, etc.
Hope this helps.


				Keith Baccki

				kiki@bass.bu.edu

Newsgroups: comp.graphics