HDTenEightyP/NetNews huggingface dataset:
From: goza@norm.JSC.NASA.GOV (Mike Goza)
Newsgroups: comp.graphics
Subject: Re: radiosity question
Date: 16 Oct 92 13:14:42 GMT
Distribution: na
Organization: IGOAL

Welcome to the world of radiosity.  Shadows are the best part of radiosity and the worst.  In your
post, you cited several cases of radiosity problems.  Shadows not having the correct prenumbra and
bleed through of shadows from underneath books sitting on tables.  There are a number of papers in
past SIGGRAPH proceedings that delve into these problems with various different methods.  The 
prenumbra problem is typically solved by brute force, i.e. automatically subdivide the patches
along the shadow boundary until a specified threshold is reached.  This threshold is usually either
an area limitation or an energy limitation.  There is no reason to compute energy values for points
in the scene if they will not change the color of a pixel in the final image.  I have also seen
BSP programs used to cut the scene up along the boundaries of the shadows and their prenumbras to 
get more precise solutions.

The book problem is similar.  The brute force method is similar to the one above.  Another method
is more complex, but results in better images.  Take the case of a box on a floor.  If you subtract
the bottom of the box from the floor, then you have a hole in the floor which will allow the patch
subdivision routine to hopefully mesh the area properly, i.e. mesh around the hole.  This 
subtraction can either be manual or automated.  Subtracting the area covered by the box will take
care of the shadow bleeding problem.

The bottom line of all this is that radiosity takes a long time to compute properly and usually uses
a fair amount of memory.  You will also notice that the actual solution to the radiosity calculation
is about 20 lines of code.  The setup and execution is the other 10000 lines ;)

Hope this helps shine a little "light" on the subject.

Mike Goza
goza@cheers.jsc.nasa.gov
Newsgroups: comp.graphics
From: rxkc2@fel.tno.nl (Ronald Kiel)
Subject: SOON: camera splines
Organization: TNO Physics and Electronics Laboratory
Date: Mon, 12 Oct 92 12:33:39 GMT


For a graphics demo we need to present on thursday (yep, 15 oct 92) I'm
looking for the following:

in the database we're showing (a 3d terrain) I have defined some track-
points which the camera should display sequentially.  I'm looking for a 
routine that will calculate the inbetweens, both the position and the 
direction in which the camera is looking.  One other restriction is that
I want to be able to control the speed with which the camera is following
that path.  So, less informal: move x meters along the path defined by 
this set of control points in the next frame.
I don't think I have to be exactly at the control points at a given time,
then again, I don't want to be way off either.
If anyone has something lying around that would do this, I would greatly
appreciate an E-mailed copy.  Thanks in advance!


Ron Kiel,
Physics and Electronics Laboratory TNO,
The Netherlands

Phone: (31)-70-3264221 x445
Email: rxkc2@tnofel.fel.tno.nl

Newsgroups: comp.graphics
From: hallvard@geomatic.no (Hallvard Naess)
Subject: Looking for articles
Organization: Geomatic a.s, Norway.
Date: Wed, 7 Oct 1992 17:19:12 GMT

I am searching for two articles which discusses the "Marching cubes"
algorithm and similar problems.  Please contact me if you know where
I can get hold of them (a paper copy or preferrably as software):

1. Bloomenthal, J. (1988).
   "Polygonalization of Implicit Surface,"
   Computer Aided Geometric Design. 5

2. Moore, Doug and Warren, Joe (1991).
   "Mesh Displacement: An Improved Contouring Method for Trivariate Data,"
   Technical Report TR 91-166. Rice University, Department of Computer Science.

--
    O  	   Hallvard Naess                | Geomatic a.s       |
   \/\\    Email: hallvard@geomatic.no   | PO. Box 165 Skoyen |
     /\_   Tel  : + 47 2 504330          | N-0212  OSLO       |
____/______Fax  : + 47 2 500555__________v_NORWAY_____________v_____
From: cs161feu@sdcc10.ucsd.edu (Anthony Minkoff)
Newsgroups: comp.graphics
Subject: Re: Looking for GIFF and TIFF FAQs
Date: 12 Oct 92 01:58:32 GMT
Organization: University of California, San Diego

In article <C54-Fd_@engin.umich.edu> lou@engin.umich.edu (Lou Rosenfeld) writes:
>Sorry if this is a FAQ itself, but could someone
>point me to or send me recent FAQ files

It's a meta-FAQ!  :-)

Tony
Newsgroups: comp.graphics
From: kyriazis@mistral.rdrc.rpi.edu (George Kyriazis)
Subject: Re: XGL and SUNVIEW at SUN: guides?
Organization: Rensselaer Design Research Center, RPI, Troy, NY
Date: Sun, 11 Oct 1992 20:30:58 GMT

In article <1992Oct8.122603.611@vms.huji.ac.il> engel@vms.huji.ac.il writes:
>Hi,
>Is there a postscripr (or tex or roff) guide for the use
>of XGL and SunView installed at SUN?
>
XGL does not work with SunView.  It works with the OpenWindows server.
The XGL documentation provides you with sample code using either XGL and
XView, or XGL and Xlib.

  --george
-- 
----------------------------------------------------------------------------
George Kyriazis       | Visual Technologies Program, Rensselaer Design
kyriazis@rdrc.rpi.edu |  Research Center, CII 7015, RPI, Troy, NY 12180
----------------------------------------------------------------------------
Newsgroups: comp.graphics,comp.graphics.visualization,comp.graphics.animation
From: marrou@cs.ucf.edu (Lance R. Marrou)
Subject: Re: FTP SITE FOR 3D OBJECT MODELS/UTILITIES
Organization: University of Central Florida
Date: Sat, 17 Oct 1992 01:57:42 GMT

I would like to see it happen, yes!  I am not sure what my
employer would like me to help with (as far as what we have
to offer) but I could possibly add some objects, textures,
and/or converters to/from Wavefront.  ;>

--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Lance R. Marrou
   Work   - Marrou@IST.UCF.edu
   School - Marrou@Eola.cs.UCF.edu
Newsgroups: comp.graphics,comp.graphics.visualization,alt.binaries.pictures
From:  dvj@lab2.phys.lgu.spb.su (Vladimir J. Dmitriev)
Subject: Q:problem with alt.binaries.pictures 
Reply-To: dvj@lab2.phys.lgu.spb.su
Organization: University of St-Petersburg, 2-nd Physics Laboratory.
Date: Fri, 9 Oct 1992 08:43:21 GMT

>How do I obtain images from alt.binaries.pictures???
>
>
>Don Anderson
>Geology/Arizona State University


>
>        I read your posting on "comp.graphics" and I tried to get the
>        image (BOLT.GIF) but, somehow my system wouldn't let me get into
>        "alt.binaries.pictures".        I have been working on similar
>        project for flow visualizations and I would love to get the image
>        would you please send me the image over e-mail"
>
>                           Thank you.
>
>                           - B. Kim -


>My site does not receive alt.binaries.pictures.  Is there a site I can reach
>with ftp?
>
>Ray Allis - Boeing Computer Services
>ray@atc.boeing.com


>This is the fourth image that you have announced that I have not seen on
>alt.binaries.pictures. The others were BOLT, FILM, and BUSH.GIF. Are you
>setting the distribution the same for alt.binaries.pictures as you are
>for these announcements in the discussion groups?
>
>Also, is there an anonymous ftp site that these images are available from?
>If not, can you email them to me so we can at least see what you are talking
>about when we read these announcements?

Dear netters,
I wonder if somebody can tell why there is a problem for  some netters
to get pictures from conference alt.binaries.pictures.
Best regards                           Vladimir.

|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|
| Vladimir J. Dmitriev                                           h   n  n    |
| Dpt. of Theoretical Physics                                    h    n  n   |
| Physical Institute                                             hhh   n n   |
| St Petersburg State University          ph:(812)4284327        h  h  nn    |
| Ulianovskaia 1  Old Petershoff        home:(812)1434823        h  h  n     |
| 198904 St Petersburg RUSSIA          e-mail dvj@lab2.phys.lgu.spb.su       |
|____________________________________________________________________________|
--




Newsgroups: comp.graphics
From: bromage@mullauna.cs.mu.OZ.AU (Andrew Bromage)
Subject: Re: Flight Simulation
Keywords: flight simulation simulator
Organization: Computer Science, University of Melbourne, Australia
Distribution: usa
Date: Mon, 12 Oct 1992 00:49:17 GMT

bpb9204@tamsun.tamu.edu (Brent) writes:

>dont@execu.execu.com (Don Thompson) writes:
>|
>| After recently becomming addicted to several filght 
>| simulators ( Hellcat [and Falcon])...

>These other simulators (Falcon) do not rival Microsoft's Flight Simulator
>as far as realism goes.  Falcon et al are good, but only as a
>"first approximation."

>| Is there a textbook approach to  programming a flight simulator,
>| or is all the execellent simulations availible today
>| based on proprietory technology?

>There are several parts of the system to consider:
>  * display - 3D graphics concepts at work here (transformations, many
>    different coordinate systems to plan into it, etc)
>  * actual flight simulation -
>    * lots of equations, time constraints, & accuracy are important issues.

Yeah, this is all well and good - transformations etc are not hard, but
_slow_. The problem here is: how can you do it in real time?

>As far as a textbook approach, I don't know of one offhand - a simulation
>seems to be a melting pot of numerical methods you have to know and love.

I seem to remember that the guy who wrote MS flight simulator wrote a book.
Does _anyone_ have a reference and, more importantly, where we can get it?

Thanks in advance,
Andrew Bromage
From: Renee.Teunissen@freudsys.nl.mugnet.org (Renee Teunissen)
Sender: Usenet@freudsys.nl.mugnet.org
Newsgroups: comp.graphics
Subject: userinterfacing for raytracers
Date: 12 Oct 92  22:13:37 EST


Hi,

I'm looking for a library which makes it easy to create a graohic user interface unther os/2 2.0 and/or ms-windows. i'm not an expert in designing  graphic userinterfaces and i think its rather boring to do [sorry can't help it].

is there anyone out there who has any bright idears about a pointer to a [pd] or shareware library which dos the dirty lowlevel work for me. so i don't have to worry about windowing, hardware support, etc..

Thanx a lot in advance!
 _
|_)
|\_enee.  

 * Origin: freusys.nl.mugnet.org, a prive uucp gate at (27:4331/107.19)
Newsgroups: comp.graphics
From: rscott@spock.NMSU.Edu (Joseph Good)
Subject: Image maping in Rayshade 4.0
Organization: New Mexico State University
Date: Sun, 11 Oct 1992 21:29:51 GMT


Could somebody out there give me the basics of image maping in
the Rayshade 4.0 ray-tracing program??

specifically, what type of file is used.

Thanks!!

-jdg

--

Joseph Good
+-------------------+ - More than just a band....
| Green Dot Brigade | - It's a whole damn army of dots...
+-------------------+ - And we've declared war on the 7-Up dots...

rscott@nmsu.edu (NeXT mail welcome!!) (main account)

atlantis@acca.nmsu.edu  (Just plain ol' Unix) (seldom used)
Newsgroups: comp.graphics
From: lou@engin.umich.edu (Lou Rosenfeld)
Subject: Looking for GIFF and TIFF FAQs
Date: Thu, 08 Oct 92 11:03:41 EDT
Organization: University of Michigan Engineering, Ann Arbor

Sorry if this is a FAQ itself, but could someone
point me to or send me recent FAQ files for TIFF
and GIFF formats?  Thanks in advance!

--Lou Rosenfeld lou@engin.umich.edu
Newsgroups: comp.graphics
From: omega2@eng.umd.edu (Wilbur S. Peng)
Subject: BGI Driver FAQ
Date: Fri, 16 Oct 92 20:38:49 GMT
Organization: College of Engineering, University of Maryland, College Park
Originator: omega2@transform.eng.umd.edu


   This may be a FAQ (in fact, it probably is) but I can't seem to find what I need...
Where can I get a BGI drivers for: ET-4000, ATI VGLWonder, other SVGA cards, as well
as mode X?  I suspect that they exist on wuarchive but cannot seem to locate them.  Just
send e-mail to me...

Newsgroups: comp.graphics
From: chris@stellacom.com (Chris Cressy)
Subject: test
Organization: StellaCom, Inc., Arlington, VA
Date: Fri, 16 Oct 1992 17:46:55 GMT


-- 
--------------------------------------------------------------------
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: mazzucch@ghost.dsi.unimi.it (massimo mazzucchi)
Subject: pc-globe
Keywords: pc-globe
Organization: Computer Science Dep. - Milan University
Date: Mon, 12 Oct 1992 12:59:12 GMT
Summary: what is pc-globe


HY

I am Max froma ITALY Milan

I want know if someone know if exist a programm like
PC-GLOBE or PC-USA about a part of town or a quarter
with information about population and othr info.

- if someone know that programm graphic it was used to
  realize PC-GLOBE or PC-USA


  Thanks for your help

  BYE


  My address is mazzucch@ghost.dsi.unimi.it
From: bouma@cs.purdue.EDU (William J. Bouma)
Newsgroups: comp.graphics
Subject: Re: wierd polygons (was Re: Determining if a polygon is convex)
Date: 15 Oct 92 21:26:56 GMT
Organization: Department of Computer Science, Purdue University


In article <1bis4bINN27r@fido.asd.sgi.com>, mtj@babar.asd.sgi.com (Michael Jones) writes:
|> Actually, the bow-tie polygon is not so unusual as it seems. Many people
|> who would claim that their data is "bowtie-free" would be surprised. The
|> most common bowtie factory is a quad as part of a surface (like a height
|> field or z=f(x,y) function plot) with heights (toward the eye) like:
|> 
|>     5------------0
|>     |            |
|>     |            |
|>     |            |   E
|>     |            |
|>     |            |
|>     0------------5
|> 
|> You look at this thing from the top, and all is well. You look from 'E' and
|> you will see a fine bow tie!

Again, this is just a mistake on the part of the surface modeler.  If 
your code does this, I consider it broken.  If you are producing polygons
whose vertices are not all in the same plane (up to some known precision)
you would do well to triangulate or take some other action.  ie. For this
application you should probably be producing a triangular mesh, not a quad!
If you need quads, perturb the points into a plane.

-- 
Bill <bouma@cs.purdue.edu>
From: joseph@joebloe.maple-shade.nj.us (Joseph Nathan Hall)
Newsgroups: comp.graphics
Subject: Jurassic Park [Re: Dinosaur animations]
Date: Fri, 9 Oct 92 12:26:49 EDT
Organization: 5 Sigma Software
Reply-To: joseph@joebloe.maple-shade.nj.us
Distribution: na
X-Mailer: uAccess - Macintosh Release: 1.5v5


In article <1992Oct6.103213.24472@jarvis.csri.toronto.edu> (comp.graphics), victorng@csri.toronto.edu (Victor Ng-Thow-Hing) writes:
) 
) Can anyone recommend any references for Dinosaur Animation?  In
) particular, my supervisor recalls a film that was shown at Siggraph a
) few years ago.  If I can get the credits to this film, that would be 
) great.  I also have heard of a film called "Dinosaur Stuff" done at Ohio and
) an upcoming series on PBS with traditional dinosaur cell animation.

Well, Spielberg's "Jurassic Park" will feature lots of ILM animation,
according to an article I saw in the San Jose Mercury News a while
back.  Supposedly the amount of animation in the film and/or the difficulty
of the animation makes the effort in Terminator 2 look puny by comparison.
I don't know what the release schedule for the film is, nor how the
hurricane that breezed through while they were filming in Kauai has
affected the schedule.  I would guess sometime next year ... late
summer, maybe?

uunet!joebloe!joseph   (609) 273-8200 day   joseph%joebloe@uunet.uu.net
2102 Ryan's Run East        Rt 38 & 41             Maple Shade NJ 80852
-----My employer isn't paying for this, and my opinions are my own-----
Newsgroups: comp.graphics
From: slaud@cc.curtin.edu.au
Subject: Flood Filling Algorithms
Organization: Curtin University of Technology
Date: Mon, 12 Oct 1992 08:03:06 GMT


I am making a programming and is encountering problems with flood filling.
It is easy to paint an entire circle, or square, but when it comes to
irregular shape, I could not figuare out a way to do it.

I was told sometimes ago that to paint an given shape, you will need
a lot of pointers. But they didn't tell me how.

So basically I am interested in the algorithm to implement a flood fill.
( please don't tell me to use BASIC and its command PAINT, as I need the
algorithm rather than the a high level language command )

Please, if someone can help me out, please mail me the informations and
the algorithms.

Deeply appreciated.

eg. fill colour blue at location x,y

 .	/---------\   /---\
 .     /           \ /     \
y-     |    _       V      /
 .     \   / \		  /
 . 	\ /   \__________/
 .	 V
 ...............|.............
		x

Daniel
From: as1@waikato.ac.nz
Newsgroups: comp.graphics
Subject: Contour tracing
Date: 10 Oct 92 09:24:31 +1300
Organization: University of Waikato, Hamilton, New Zealand

Hi,

I am looking for alogrithms to perform contour tracing which will enable me to
detect objects lying in enclosed areas. For instance, a stroke lying inside
a rectangle.

At the moment I am able to extract, as in the above case, the rectangle and the 
stroke but I would like to further process the image so that I am able to
detect that the stroke lies inside the rectangle.

Any reference to articles( or books) on contour tracing algorithms would be
highly appreciated. Sources of such code would be an advantage.

abdul.
From: engel@vms.huji.ac.il
Newsgroups: comp.graphics
Subject: XGL and SUNVIEW at SUN: guides?
Date: 8 Oct 92 12:26:03 GMT
Distribution: world
Organization: The Hebrew University of Jerusalem

Hi,
Is there a postscripr (or tex or roff) guide for the use
of XGL and SunView installed at SUN?
Thanks,
Micky Engel
(address: engel@hujivms.bitnet
 or engel@hula.huji.ac.il)

Newsgroups: comp.graphics,comp.graphics.visualization,comp.graphics.avs
From: m20163@mwunix.mitre.org (Nahum Gershon)
Subject: IEEE Visualization '92 Conference, Boston, October 19-23
Summary: IEEE Visualization '92 Conference will take place in Boston, MA, on Oct
Keywords: Visualization, preception, image processing, medical imaging, graphics
Organization: The MITRE Corporation
Date: Thu, 8 Oct 1992 20:00:19 GMT


IEEE Visualization '92 Conference

Boston Park Plaza Hotel
19-23 October 1992

	Scientific Visualization is an important research frontier shared by 
a variety of computational science & engineering fields.  Visualization 
work is both interdisciplinary and a field of its own right.  This 
conference focuses on interdisciplinary methods and supports 
collaboration among the developers and users of visualization 
methods across science, engineering, and commerce.

The conference includes the following sessions:

Keynote Address: "High Performance Computing and 
Communications"

Keynote Panel: "Interactions Between Science and Visualization"

Tutorials:
	Volume Visualization
	Virtual Environment
	Visual Perception for Visualization and Image Processing
	Color Theory and Models
	Topology, Vector Fields, and Flows
	Automating the Design of Effective Graphics
	Visualization of Multidimensional and Multivariate Data

Workshops

Panels:
	Managing Large Scientific Data Bases
	Grand Challenge Problems in Visualization Software
	Improving visualization:  Perceptual Foundations
	Real Virtual Environments Applications - Now
	Visualization in the Neurosciences
	Object-Oriented Dataflow Visualization Systems

Paper Sessions:
	Volume Visualization
	Flow Visualization
	Surface Visualization
	Visualization Systems
	Data Structures
	Visual Programming
	Visualization Software Systems
	Visualization Techniques and Methods
	Terrain Visualization

Case Studies Sessions on Physics, Life Sciences, the Environment, and 
Fluid Dynamics

Special Sessions:
	Research Problems in Visualization
	How to Lie and Confuse With Visualization

Capstone Address:  "Parallel Processing of Form, color, Motion, and 
Depth:  Anatomy, Physiology, Art, and Illusion"

For more information, call the VIS92 phone, (510) 423-9368
or
Haim Levkowitz, (508) 934-3654, haim@cs.ulowell.edu
Newsgroups: comp.graphics
From: niko@iastate.edu (Nikolaus E Schuessler)
Subject: Re: PHIGS Users Group Conference
Keywords: PHIGS
Organization: Iowa State University, Ames, IA
Date: Fri, 16 Oct 1992 21:33:19 GMT

Could someone tell me (FMI) in a short post
what PHIGS stands for? 

Thanks...



-- 
Niko Schuessler               
Project Vincent Systems Manager              email: niko@iastate.edu
Iowa State University Computation Center     voice: (515) 294-1672
Ames IA 50010                                snail: 272 Durham
From: zhu@sgi.com (Benjamin Zhu)
Newsgroups: comp.graphics
Subject: Re: Determining if a polygon is convex
Date: 16 Oct 1992 00:40:25 GMT
Organization: Silicon Graphics, Inc.
NNTP-Posting-Host: graphack.asd.sgi.com

In article <1992Oct15.222817.18591@neptune.inf.ethz.ch> schorn@inf.ethz.ch (Peter Schorn) writes:
>Problem: Given a polygon P with n vertices p(1) to p(n). Determine
>in O(n) time whether the polygon is convex. Note: P might be self
>intersecting.
>
>Assumptions and definitions:
>1) All indices are calculated modulo n.
>2) p(1) has the smallest x-coordinate and in case of ties the
>   smallest y-coordinate (otherwise a O(n) time cyclic shift is
>   necessary).
>3) p(m) has the largest x-coordinate and in case of ties the
>   largest y-coordinate (m can be found in time O(n)).
>4) The predicate rightTurn(p, q, r) is true if and only if
>   the point r lies to the right or on the directed line
>   segment from p to q.
>5) rightTurn(p(1), p(2), p(m)) since the case
>   'not rightTurn(p(1), p(2), p(m)' is symmetric.
>
>Idea: A convex polygon consists of a monotone convex upper chain and
>      monotone convex lower chain. The following should also work
>      for degenerate cases.
>
>Solution:  P is convex if and only if the x-coordinates of
>p(1) to p(m) are monotonically increasing and the x-coordinates
>of p(m) to p(n+1) are monotonically decreasing and there is a
>right turn at each vertex.

	One of the best pieces of work I have seen for quite a
	while. (Or am I just getting dumber?:-)

	I would like to thank Peter for shedding light on this.
	Whoever in charge of the faq list may want to add this
	solution into the faq list.

>
>P is convex <==> p(i).x <= p(i+1).x for 1 <= i < m  and
>                 p(i).x >= p(i+1).x for m <= i <= n and
>                 rightTurn(p(i-1), p(i), p(i+1)) for 1 <= i <= n
>
>This can be calculated in time O(n).
>
>
>Peter Schorn     schorn@inf.ethz.ch

	Out of curiosity, did you know this solution all along,
	or did you solve this at ease just yesterday?

	Thanks again for enlightening us.

	Ben

--
Benjamin Zhu             ;;; Priest of ucode and self-appointed bug terminator
Silicon Graphics, Inc.   ;;; ``Just call my name, I will be there.''
zhu@graphack.asd.sgi.com ;;; ``Projective geometry is all geometry.'' - Cayley
(415) 390-1187           ;;; ``Learn forever, young forever.'' - Anonymous
From: fagan@coombs.anu.edu.au (Michael Fagan)
Newsgroups: comp.graphics
Subject: WANTED: Text 2 POV untility for Mac
Followup-To: comp.graphics
Date: 12 Oct 1992 05:58:54 GMT
Organization: Australian National University
Distribution: world
NNTP-Posting-Host: 150.203.34.45

I was wondering if anyone knows of a text(truetype of otherwise) 2 POV
convertor
(preferably for the mac)


---
Michael Fagan
Newsgroups: comp.graphics
From: brian@next (Brian Mayoh)
Subject: EdgeTracing,colour and gray HELP
Organization: DAIMI: Computer Science Department, Aarhus University, Denmark
Date: Mon, 12 Oct 92 10:23:06 GMT

We would be grateful for any info/references on edge tracing in
grey-scale or colour pictures- we are trying to construct 3Dship images
from 2Dimages. If many replies we will make reflist for newsgroup.
			Regards     Brian
Newsgroups: comp.graphics