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comp.graphics.rendering.raytracing FAQ (part 1/2)

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Andreas Dilger

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Feb 2, 1996, 3:00:00 AM2/2/96
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Archive-name: graphics/raytrace-faq/part1
Last-modified: 1996/01/29
Posting-Frequency: every 10 days


"But the Devil whoops, as he whooped of old:
'It's clever but is it art?'"
Rudyard Kipling
_The_Conundrum_of_the_Workshops_

This is the comp.graphics.rendering.raytracing Frequently Asked
Questions (FAQ) List. It's not the most definitive ray tracing
reference you'll ever come across, but then, it was never meant to be.
What it does set out to do is to answer some of the questions which keep
cropping up on c.g.r.r and to give pointers to other references. It
keeps the noise down on the group and we get to spend an extra 10
minutes in bed. This is a Good Thing.

It was originally cobbled together by Andy Wardley,
<a...@peritas.demon.co.uk>, from answers posted to c.g.r.r (actually from
when it was c.g.r), from information people have supplied and from other
existing ray tracing lists and references, most notably, Eric Haines'
Ray Tracing News and other lists. Since the spring of 1995, I have
taken over the maintenance of the FAQ.

You may distribute this document to whoever, or wherever you like, as
long as you keep the copyright message and give correct attributions for
material used. This is just to stop nasty people with a substantial
lack of moral fibre from taking the document and fobbing it off as their
own. The FAQ belongs to the group, Andy just wrote it (and I update it).

Lines with a + in the first column have been added or changed recently.
If you think that parts of the FAQ are outdated, or need improvement,
please feel free to send me your updates, and I will try to maintain and
update it, as time permits. Authors of utilities should definitely send
updated descriptions if they feel their tool has improved since this was
written.

The latest version of this FAQ is available via WWW at:

http://www.cis.ohio-state.edu/hypertext/faq/bngusenet/top.html

under comp->graphics->rendering->raytracing. It is also available via
anonymous ftp at:

ftp://rtfm.mit.edu/pub/usenet/news.answers/graphics/raytrace-faq/

If you only have email, you can get it by sending email to:

<mail-...@rtfm.mit.edu>

with both

"send usenet/news.answers/graphics/raytrace-faq/part1" and
"send usenet/news.answers/graphics/raytrace-faq/part2"

in the body of the message (without the quotes).

And if you're only reading this document because your machine is locked
up tracing, remember that all things come to those who wait.

Andreas Dilger <adi...@enel.ucalgary.ca>

(C) Copyright 1994 Andy Wardley
<a...@peritas.demon.co.uk>
(C) Copyright 1995, 1996 Andreas Dilger
<adi...@enel.ucalgary.ca>

------------------------------

Subject: Table of Contents

What is Ray Tracing?

1 - Ray Tracing Software

1.1 - POV-Ray
1.2 - Polyray
1.3 - Vivid (including BOB)
1.4 - Rayshade
1.5 - Radiance and ADELINE
1.6 - Others
1.7 - Non-Ray Tracing Software

2 - FTP Sites, Web Sites, Bulletin Boards, etc.

2.1 - FTP Sites
2.2 - Bulletin Board Systems
2.3 - Mailing Lists
2.4 - Others

3 - Modelling Software

3.1 - MORAY
3.2 - SCED
3.3 - GUM
3.4 - Other Modellers

4 - Utilities and Other Software

4.1 - Image Display/Conversion Programs
4.2 - Format Conversion Utilities
4.3 - Creation Creators
4.4 - Texture Editors
4.5 - Animation
4.6 - Miscellaneous Utilities

5 - Further Information and Resources

5.1 - On-line Resources
5.2 - Other Newsgroups
5.3 - Books
5.4 - Image Libraries
5.5 - Texture Libraries

6 - Frequently Asked Questions

6.1 - "Who is..."
6.2 - "This picture doesn't trace."
6.3 - "I traced my picture, but I can't see anything."
6.4 - "I traced my picture, but the output is garbage."
6.5 - "How can I view these pictures?"
6.6 - "Rotating/Scaling this object doesn't work properly."
6.7 - "Where can I find model data for..."
6.9 - "Can I post binaries/images to this group?"
6.9 - "What does this mean..."
6.10 - "What is the difference between rendering and ray-tracing?"
6.11 - "When will POV-Ray 3.0 come out?"
6.12 - "Where are the .inc files for POV-Ray?"

7 - Roll The Credits...


------------------------------

Subject: What is Ray Tracing?

Ray Tracing, in a one-line description, is a method that allows you to
create stunning photo-realistic images on a computer. All you need is
a computer, some ray tracing software, a little imagination and some
patience.

The first stage of creating this masterpiece is to "describe" what it is
that you want to depict in your picture. You may do this using an
interactive modelling system, like a CAD package, or by creating a text
file that has a programming language-like syntax to describe the
elements. Either way, you will be specifying what objects are in your
imaginary world, what shape they are, where they are, what colour and
texture they have and where the light sources are to illuminate them.
Having done all of this, you feed it into your ray tracer, sit back and
wait.

And wait...

That's the main drawback of ray tracing - it's not fast. The software
actually mathematically models the light rays as they bounce around this
virtual world, reflecting, refracting and generally having a good time
until they end up in the lense of your imaginary camera. This can quite
literally involve thousands and millions of floating-point calculations
and this takes time. Tracing images can take anything from a few
minutes to many days. It's a long process, I know, but the results can
make it all worth while.

Ray tracing isn't the only method for creating photo-realistic pictures.
There are packages like 3D Studio which uses scanline rendering,
Radiance, which uses radiosity, and so on. Although these don't count
as ray tracing, the methods you use from one system to the next are
often sufficiently similar to warrant their discussion in this group.
So if you think it's relevant, feel free to bring it up. These systems
will be mentioned in a little more detail later on.


------------------------------

Subject: 1 - Ray Tracing Software

------------------------------

Subject 1.1 - POV-Ray

The Persistance of Vision Ray Tracer (POV-Ray) is an all-round
excellent package, but there are two things that particularly make it
stand out above the rest of the crowd. Firstly, it's free, and
secondly, the source is distributed so you can compile it on virtually
any platform. It's without doubt the most used package among the
comp.graphics.rendering.raytracing crowd and well worth checking out
if you haven't already.

POV-Ray is based on David Buck's original ray tracer, DKB-Trace and
has been (and still is) developed and supported by a whole crowd of
people on CompuServe Graphics Developers' Forum (GO GRAPHDEV). For
more info, see the POV-Ray docs.

The latest version currently available is 2.2 and the following list,
taken from the official POV-Ray docs, details some of the main features.
For those of you who are wondering, "No, POV-Ray 3.0 is not yet available."

* Easy to use scene description language
* Large library of stunning example scene files
* Standard include files that pre-define many shapes, colors and
textures
* Very high quality output image files (24-bit color.)
* 15 and 24 bit color display on IBM-PC's using appropriate hardware
* Create landscapes using smoothed height fields
* Spotlights for sophisticated lighting
* Phong and specular highlighting for more realistic-looking surfaces.
* Several image file output formats including Targa, dump and raw
* Basic Shape Primitives:
Sphere, Box, Quadric, Cylinder, Cone, Triangle and Plane
* Advanced Shape Primitives:
Torus (Donut), Hyperboloid, Paraboloid, Bezier Patch, Height
Fields (Mountains), Blobs, Quartics, Smooth Triangles (Phong
shaded)
* Shapes can easily be combined to create new complex shapes. This
feature is called Constructive Solid Geometry (CSG). POV-Ray
supports unions, merges, intersections and differences in CSG.
* Objects are assigned materials called textures. (A texture
describes the coloring and surface properties of a shape.)
* Built-in color patterns:
Agate, Bozo, Checker, Granite, Gradient, Leopard, Mandel, Marble,
Onion, Spotted, Radial, Wood and image file mapping.
* Built-in surface bump patterns:
Bumps, Dents, Ripples, Waves, Wrinkles and mapping.
* Users can create their own textures or use pre-defined textures:
Mirror, Metals like Chrome, Brass, Gold and Silver, Bright Blue
Sky with Clouds, Sunset with Clouds, Sapphire Agate, Jade, Shiny,
Brown Agate, Apocalypse, Blood Marble, Glass, Brown Onion, Pine
Wood, Cherry Wood
* Combine textures using layering of semi-transparent textures or tile
or material map files.
* Display preview of image while computing (not available on all
systems)
* Halt rendering when part way through and resume later

There are now three official distribution sites for POV-Ray.
ftp://ftp.povray.org/ [192.216.222.14] the main site in North America.
ftp://alfred.ccs.carleton.ca/ [134.117.1.1] an alternare site.
ftp://uniwa.uwa.edu.au/ [130.95.128.1] for the Southern Hemisphere.

There is also a growing list of sites that mirror all or part of
ftp.povray.org (see 2 - FTP Sites, Web Sites, Bulletin Boards, etc.).

The files that make up POV-Ray are:

- povsrc-2.2.zip Source files for compiling POV-Ray yourself.
- povdoc-2.2.zip Documentation
- povscn-2.2.zip Sample scenes
- povibm-2.2.exe Runtime binary for IBM PC systems.

Depending on where you look, you may also find binaries for other
platforms or the above archives packaged in different formats.

Definately worth a mention here is Dieter Beyer's Faster Than
POV-Ray (FTPOV) which is a custom build that incorporates many
speed-ups and enhancements to the original POV-Ray. Not all scenes
benefit from the enhancements and some may even run slower, but in
certain cases, speed increases by an order of magnitude are
possible. The archive ftpv22.zip is available from most of the
major POV FTP sites.

If you have access to several networked computers and a compiler,
it is possible to have POV-Ray render using multiple CPUs using the
PVM system of distributed computing. More information is at:
http://www-mddsp.enel.ucalgary.ca/People/adilger/povray/pvmpov.html

[hype on]
At long last, the Official POV-Ray CD-ROM is available from Walnut
Creek. finger in...@cdrom.com to get up-to-date ordering information.
The POV-Ray CD-ROM (the OFFICIAL version!) is a compilation of images,
scene source, program source, utilities and tips on POV-Ray and 3D
graphics from the Internet and Compuserve. It contains the source for
version 2.2 of POV-Ray, as well as binaries for DOS, Macintosh, OS/2,
Amiga, Linux, and several other platforms. The disk contains a
specially produced Microsoft Windows-based interactive tutorial
designed for beginners. This disk also contains scene source files
(some of them never before released), utilities, modellers and
graphics source code. The disk is in ISO9660 format and Macintosh.
Comes with full color poster/cheat sheet. For your browsing pleasure,
you can have a look at almost the whole contents of the CD-ROM at:
http://www.povray.org/pov-cdrom/
[hype off]

------------------------------

Subject 1.2 - Polyray

The program Polyray is a rendering program for producing scenes of
3D shapes and surfaces. The means of description range from
standard primitives like box, sphere, etc. to 3 variable polynomial
expression, and finally (and slowest of all) surfaces containing
transcendental functions like sin, cos, log. Polyray supports
rendering in a number of different modes: Raytracing, Zbuffered
polygon rendering (fully textures or Gourad shaded), wireframe and
hidden line, and raw triangles (as ASCII output, one tri per line).

Polyray supports the following general features:

* Viewpoint (camera) characteristics
* Lights: point, directional, spotlight, functional, and area
* Background color
* Shape primitives:
Bezier patch, blob, box, cone, cylinder, disc, glyph, implicit
function, heightfield, hypertexture, lathe surface, NURBS,
parabola, parametric function, polygon, polynomial function,
sphere, superquadric, sweep surface, torus, triangular patches
* Animation support
* Conditional processing
* Include files
* Named values and objects
* Hierarchical objects and Constructive Solid Geometry (CSG)
* Grids of objects
* User definable (functional) textures
* Initialization file for default values
* Simple particle systems
* Spline evaluation for path animations
* Lens flare effects
* 3D point/line/spline drawing

Polyray supports a number of features not found in any other shareware
or freeware raytracer. These include objects such as sphericial and
cylindrical heightfields, cylindrical and planar blob components,
parametrically defined objects, non-polynomial functional objects,
gridded objects, and glyph objects. Polyray is also the only
raytracer that supports true displacement surfaces (more than simple
bump map texturing, although that's there too).

The raw triangle output of Polyray can be useful as a way to build
complex objects and export them to other rendering an simulation
packages.

The texturing in Polyray is not limited to a few predefined styles -
you can use mathematical expressions to modify any part of the
shading.

If you find Polyray valuable and can afford it, the registration cost
is $35.00. Note that the version available online is the complete
thing. Polyray is not crippled in any way, nor are there any annoying
nag screens.

The extended DOS version of Polyray is currently available at:
ftp://ftp.povray.org/pub/polyray

UNIX versions are available at:
http://www.inf.fu-berlin.de/~leitner/grafik/polyray.html
(binaries for: HP-UX, Linux, FreeBSD, Sun OS 4&5, SGI/IRIX 4&5)

------------------------------

Subject 1.3 - Vivid (including BOB)

Vivid is a shareware ray tracer for IBM PC's by Stephen Coy
<sc...@microsoft.com>. Version 2, the current publicly available
version, is available from several FTP sites as vivid2.zip.
Version 3 is expected soon (I expect it is already available [AED]).

Compared to POV-Ray, Vivid doesn't have as many features, but in many
cases it can run faster. Source code isn't available, so the package
is limited to systems which can run DOS executables.

Stephen Coy, Christopher Watkins and Mark Finlay co-authored a book on
Ray Tracing called "Photorealism and Ray Tracing in C". Distributed
free with the book was an example ray tracer called BOB. This was
actually a cut down version of Vivid which did include source.
(see also 5 - Further Information and Resources).

------------------------------

Subject 1.4 - Rayshade

Rayshade is a free ray tracing package for unix/X11. The "official"
ftp site is:
ftp://princeton.edu/pub/Graphics/

There is are two programs to distribute rayshade traces over multiple
machines. One is called inetray, the other raynet, available at:
ftp://maggia.ethz.ch/pub/inetray/
ftp://mars.sapham.debis.de/pub/raynet/

+ ** Rayshade is much too widely used to not have a good description
+ ** here. If anyone could add some more desription about rayshade,
+ ** it would be greatly appreciated. Please email me.

------------------------------

Subject 1.5 - Radiance and ADELINE

Radiance is a free Unix software package that adopts a radiosity- type
approach to lighting simluation. A MS-DOS version is now available as
part of the ADELINE 1.0 software package for a site license fee from
Lawrence Berkeley National Laboratory.

Greg Ward <gjw...@lbl.gov>, discusses Radiance here:

"I've spent the past ten or so years developing a ray-tracing program
for lighting simulation and rendering called Radiance. Although it
doesn't use the typical finite-element/form-factor approach of
radiosity programs, it does compute what they compute plus some.
Specifically, Radiance computes diffuse, specular and directional-
diffuse reflection and transmission in arbitrarily complicated
environments.

Here is a short description:

Radiance is a suite of programs for the analysis and visualization of
lighting in design. Input files specify the scene geometry,
materials, luminaires, time, date and sky conditions (for daylight
calculations). Calculated values include spectral radiance (ie.
luminance & color), irradiance (illuminance & color) and glare
indices. Simulation results may be displayed as color images,
numerical values and contour plots. The primary advantage of Radiance
over simpler lighting calculation and rendering tools is that there
are no limitations on the geometry or the materials that may be
simulated. Radiance is used by architects and engineers to predict
illumination, visual quality and appearance of innovative design
spaces, and by researchers to evaluate new lighting and daylighting
technologies.

Radiance has been written up in many technical and non-technical
articles in various journals and magazines. Most recently, a
Radiance-generated image appeared on the cover of the 1992 Siggraph
Proceedings.

There are hundreds of happy Radiance users world-wide, including
public and private research institutions as well as engineering and
architecture firms.

I guess that's all I can think of to say about it at the moment..."

-Greg

The Unix version of the software is free, in source code, runs on most
UNIX/X11 platforms (including Linux), and is available in source form:
ftp://hobbes.lbl.gov/ [128.3.12.38] in California and
ftp://nestor.epfl.ch/ [128.178.139.3] in Switzerland.

The Radiance WWW home page can be found at:
http://radsite.lbl.gov/radiance/HOME.html

A version of Radiance for MS-DOS is available as part of a software
package called ADELINE. ADELINE is being distributed by Lawrence
Berkeley National Laboratory for a site-license fee of $450.00 US.
For detailed information, please browse:
http://radsite.lbl.gov/adeline/HOME.html

An ftp site with basic information and an order form is available at:
ftp://hobbes.lbl.gov/pub/adeline

for PC to: <ckeh...@lbl.gov>

------------------------------

Subject 1.6 - Others

There are many other ray tracing packages available; ART, DKBtrace,
RTrace, RAY4, MTV, QRT, and DBW for instance, and some for parallel
tracing: XDART, RRLib, prt, and VM_pRAY. Eric Haines' <er...@eye.com>
Ray Tracing News (see 5 - Further Information and Resources), or the
comp.graphics.misc FAQ for more info.

+ The Blue Moon Rendering Tools (BMRT) is of special note because it is
+ a shareware ray-tracing and radiosity implementation of the language.
+ For more info point your browser at:
+ http://www.seas.gwu.edu/student/gritz/bmrt.html

------------------------------

Subject 1.7 - Non-Ray Tracing Software

* Pixar's Photo-Realistic Renderman
Because of the excellent and sophisticated techniques used in PRMan,
many people think that it is a ray tracer, when in fact PRMan is a
scanline based software package. PRMan is the grand-daddy of all
high-end rendering packages, and was the source of many of the
techniques used in rendering software today. Pixar showcased their
skills in short animations such as Tin Toy and Red's Dream. PRMan
to animate the Walt-Disney feature film Toy Story.

There is a newsgroup news:comp.graphics.rendering.renderman devoted
to the discussion of all implementations of the Renderman language.

* 3D Studio
Autodesk's 3d Studio is an interactive 3d modelling, rendering and
animation package for the IBM PC platform. It employs scanline
rendering to achieve photo-realistic effects rather than
ray-tracing. Because of this, it cannot do true shadows,
reflections or refractions, but can, in many cases, simulate them
accurately enough for most purposes. The package costs around $3000
or $1200 with the educational discount. There is a newsgroup for
discussions on this package. news:comp.graphics.packages.3dstudio

* Alias
The newsgroup for this software is news:comp.graphics.apps.alias

* Lightwave
The newsgroup for this software is news:comp.graphics.apps.lightwave

Note that there is also a group news:comp.graphics.rendering.misc
for the discussion of general rendering issues.

------------------------------

Subject: 2 - FTP Sites, Web Sites, Bulletin Boards, etc.

------------------------------

Subject 2.1 - FTP Sites

The following list details some of the main graphics related FTP
sites, their maintainers (where known) and any other info.

For a more complete list of FTP sites, see the list by Eric Haines
<er...@eye.com> and Nick Fotis <nfo...@theseas.ntua.gr> from which
much of the following has been taken.

* ftp://wuarchive.wustl.edu/ [128.252.135.4]
George Kyriazis <kyri...@esd.sgi.com>

A huge repository of graphics stuff, particulary:

- /graphics/graphics - get CONTENTS file.
- /graphics/graphics/objects/TDDD - the TDDD objects and converters.
- /mirrors/unix-c/graphics - Rayshade, MTV, Vort, FBM, PBMPLUS, etc.
- /mirrors/msdos/graphics - DKB ray tracer, FLI RayTracker demos.
- /graphics/graphics/mirrors - mirrors many sites.
- /pub/rad.tar.Z - SGI_RAD.
- /graphics/graphics/radiosity - Radiance and Indian packages.
- /systems/ibmpc/msdos/graphics - loads of PC graphics stuff.

* ftp://ftp.informatik.uni-oldenburg.de/ [134.106.1.9]
Frank Neumann <Frank....@informatik.uni-oldenburg.de>

Another good site for ray tracing, particulary POV-Ray. Recently
been re-organised:

- /pub/pov-ray - get INDEX for full details
- /pub/pov-ray/conv - format converters
- /pub/pov-ray/edit - graphical editors
- /pub/pov-ray/ext - source extensions
- /pub/pov-ray/gen - data file generators
- /pub/pov-ray/misc - other tools, ray tracers, etc.
- /pub/pov-ray/new - uploads
- /pub/pov-ray/obj - objects
- /pub/pov-ray/pack - compression
- /pub/pov-ray/pix - pictures
- /pub/pov-ray/scen - scenes
- /pub/pov-ray/text - text articles
- /pub/pov-ray/view - viewers
- /pub/pov-ray/pbin - unofficial POV binaries

* ftp://ftp.povray.org/ [192.216.222.14]
http://www.povray.org/ [192.216.222.14]
Christopher Cason <Chris...@oaks.com.au>

This has become the primary site for POV-Ray. It contains a large
number of POV-Ray utilities, executables, and scenes. This site has
also grown to have a mirror of avalon.vislab.navy.mil (see below),
as well as polyray and rayshade.

- /pub/povray/Hall-Of_Fame - incredible ray-traced images
- /pub/povray/Official - official sources and executables
- /pub/povray/Ray-Tracing-News - archive of Eric Haines' newsletter
- /pub/povray/animation - animations created with POV-Ray
- /pub/povray/ezine - a magazine about POV-Ray
- /pub/povray/fonts - font utilities
- /pub/povray/modellers - CAD packages for creating POV scene files
- /pub/povray/objects - a collection of POV objects
- /pub/povray/scenes - complete POV-Ray scene files
- /pub/povray/unofficial - modifications and executables by others
- /pub/povray/utilities - tools and programs to make life easier
- /pub/competition - monthly ray-tracing competition images
- /pub/mirrors/avalon - mirror of avalon.vislab.navy.mil (Objects)
- /pub/polyray - polyray source files
- /pub/rayshade - rayshade source files

Due to increasing demand for better access, ftp.povray.org now has
several mirror sites around the world. If you have a choice, use
the http (WWW) mode, rather than the ftp mode, since it puts less
load on the server.

ftp://alfred.ccs.carleton.ca/ (Official) [134.117.1.1]
ftp://uniwa.uwa.edu.au/ (Official) [130.95.128.1]
ftp://sunsite.wits.ac.za/pub/mirrors/ [146.141.15.214]
http://wuarchive.wustl.edu/graphics/graphics/mirrors/ [128.252.135.4]
ftp://wuarchive.wustl.edu/graphics/graphics/mirrors/ [128.252.135.4]
ftp://plaza.aarnet.edu.au:/graphics/graphics/mirrors/ [139.130.23.2]
ftp://ftp.shu.ac.uk/pub/computing/packages/raytrace/ [143.52.20.24]
+ http://www.hensa.ac.uk/ftp/mirrors/povray/ [129.12.200.129]
+ ftp://www.hensa.ac.uk/ftp/mirrors/povray/ [129.12.200.129]
http://ftp.nectec.or.th/pub/mirrors/ray-tracing/ [192.150.251.33]
ftp://ftp.nectec.or.th/pub/mirrors/ray-tracing/ [192.150.251.33]
+ ftp://ftp.etsimo.uniovi.es/pub/raytrace/ [156.35.23.24]

+ The POV-Ray CD-ROM from Walnut Creek Raytrace! is now available
+ online. Check it out at:
+ http://www.povray.org/pov-cdrom/

* ftp://ftp.princeton.edu/ [128.112.128.1]
Craig Kolb <c...@princeton.edu>

- /pub/Graphics/GraphicsGems - source code from Graphics Gems books
- /pub/Graphics/URT - Utah Raster Toolkit
- /pub/Graphics/SPD - Standard Procedural Database
- /pub/Graphics/rayshade - rayshade source code
- /pub/Graphics/RTNews - Ray Tracing News
- /pub/Graphics/Papaers - ray tracing papers, bibliographies

* ftp://avalon.viewpoint.com/ [204.212.34.3]
http://www.viewpoint.com/ [204.212.34.10]
Webmaster <s...@viewpoint.com>

Avalon was created to be a 3D object "repository" for the net. 3D
objects (multiple formats), utilities, and file format documents are
only part of what is available here. Since July 1995, Avalon has
been run by Viewpoint, a commercial 3D model vendor, but they insist
that the Avalon models will still be available for free to all.
This site is also mirrored by (among others):

http://wuarchive.wustl.edu/graphics/graphics/mirrors/avalon/
ftp://sunsite.wits.ac.za/pub/mirrors/ftp.povray.org/mirrors/avalon/

* http://cedar.cic.net/~rtilmann/mm/ [192.131.22.3]
Webmaster <rtil...@cedar.cic.net>

Meshmart is a repository of 3D objects in a variety of formats. Not
only does meshmart have objects available, they also have objects on
consignment as well as an "objects wanted" area.

* ftp://hobbes.lbl.gov/ [128.3.12.38]
http://radsite.lbl.gov/radiance/HOME.html [128.3.12.33]
Greg Ward <gjw...@lbl.gov>

Official distribution site for Radiance ray trace/radiosity package.

* ftp://ftp.cs.berkeley.edu/ [128.32.35.31]

- /pub/graphics/mm/encode - MPEG encoding software
- /pub/graphics/mm/play - MPEG decoding/display software

* ftp://rtfm.mit.edu/ [18.70.0.209]
http://www.cis.ohio-state.edu/hypertext/faq/bngusenet/top.html
[164.107.8.52]

- /pub/usenet/news.answers - the land of FAQs.

------------------------------

Subject 2.2 - Bulletin Board Systems

The following list details some Bulletin Boards Systems dedicated to
graphics and, in particular Ray Tracing. At the end of the section
there is a list of BBS'es of PCGNet (Professional CAD and Graphics
Network) kindly provided by Bjorn-Kare Nilssen <bjo...@oslonett.no>
This list may be out of date at the time of printing. If you know one
of the boards here no longer works please let me know.

* The Graphics Alternative

TGA is heavily orientated around Ray Tracing, 3D Rendering,
Modelling and Animation. It's the official support BBS for Vivid
and has an extensive library of utilities, programs, source and
images built up by its 1300+ users.

Location: El Cerrito, CA, USA.
Sysop: Adam Shiffman
Data: (510) 524-2780 (PM14400FXSA v.32bis 14.4k, Public)
(510) 524-2165 (USR DS v.32bis/HST 14.4k, Subscribers)
WWW: http://www.tgax.com/

* Pi Squared

On the East Coast of the USA is Pi Squared. Alfonso Hermida is the
sysop and he is the creator of POVCAD. All the latest POV files
available as well as support for his own products.

Location: Maryland, USA.
Sysop: Alfonso Hermida (CIS: 72114,2060)
Data: (301) 725-9080 (14.4K, 24hrs)

* The Tackle Box

A huge BBS dedicated to POV-Ray with hundreds of modelling
utilities, source, pictures and animations. 2 GIG online, 24 hours
a day. Walnut Creek "RayTrace!" CD ROM is now loaded with 200 file
areas. The first month is 100% FREE with subscriptions available
for $20/year.

Location: Edmond, Oklahoma, USA.
Sysop: Neil Clark <cl...@ionet.net>
Data: (405) 359-3301 (14.4K, N/8/1, 24hrs)
WWW: http://www.ionet.net/~clark/ (Files available for ftp)

* The New Graphics BBS

A graphics specific system for those interested in 3D, objects,
image processing, animation, MPEG, JPEG, GIF, file formats, etc.
Knowledge Media "Graphics 1" CD-ROM available, 645 Mb "MultiMedia"
CD online shortly.

Location: ?
Sysop: Bob Lindabury <b...@bobsbox.rent.com>
Data: (908) 469-0049 (14.4K, 24hrs)

* The Graphics Emporium BBS

A BBS for the graphics professional and hobbyist to exchange ideas,
information and creativity. Not dedicated to any one platform.

Location: Redondo Beach, CA, USA.
Sysop: ? <Emporium_Admin%Graphics...@morph.uu.holonet.net>
Data: (310) 374-8805

* Windows World BBS

Specializing in DOS/Windows based ray tracing, mathematics, stock
market technical analysis and also the latest CICA Windows CDs
(1 gig). No fees and free access. Requires Windows 3.1 and the
Excalibur(tm) client communications program to access the BBS. It
is down-loadable on the first call.

Location: Dayton, OH, USA
Sysop: H. Lawrence Rowe (hr...@erinet.com)
Data: (513) 866-8181 (V.22-V.34, 24hrs)

* Boards of the Professional CAD and Graphics Network

USA and Canada
-------------------------------------------------------------------
SAUG BBS Bellevue WA 206-644-7115
Joes CODE BBS West Bloomfield MI 313-855-0894
Engineering Services Atlanta GA 404-325-0122
Autodesk Global Village Sausalito CA 415-289-2270
The Graphics Alternative El Cerrito CA 510-524-2780
PC-AUG Phoenix AZ 602-952-0638
Convergence Spline BBS Richmond BC 604-275-3462
Graphicly Speaking Langley BC 604-534-2954
Tern Solution BBS Ottawa ON 613-228-0539
Canis Major Nashville TN 615-385-4268
CAD Engineering Services Hendersonville TN 615-822-2539
The Virtual Dimension Oceanside CA 619-722-0746
The Drawing Board BBS Anchorage AL 907-349-5412
The University Shrewsbury Twp NJ 908-544-8193

France
-------------------------------------------------------------------
CAD Connection Montesson 33-1-39529854
Zyllius BBS! Saint Paul 33-93320505

United Kingdom
-------------------------------------------------------------------
Raytech BBS Tain, UK 44-1862-832020
The Missing Link Surrey, England 44-81-641-8593
CADenza BBS Leicester, UK 44-533-596725

New Zealand
-------------------------------------------------------------------
The Graphics Connection Wellington 64-4-566-8450

Australia
-------------------------------------------------------------------
The Baud Room Melbourne 61-3-481-6873
Sydney PCUG Compaq New South Wales 61-2-540-1842
My Computer Company Erskineville 61-2-557-1489

Slovenia
-------------------------------------------------------------------
MicroArt Koper 386-66-34986

Germany
-------------------------------------------------------------------
NEWS BBS Duesseldorf 49-211-680-1458

The Netherlands
-------------------------------------------------------------------
BBS_Bennekom: Fractal Board Bennekom 31-8389-15331
CAD-BBS Amsterdam 31-3402-90287
Foundation One Baarn 31-2154-22143

Some of the above may require additional country or long-distance
codes.

------------------------------

Subject 2.3 - Mailing Lists

Listed below is a selection of mailing lists related to graphics
and/or ray tracing. If I haven't included specific details on
subscription, it's because I don't know. Best bet is to send a
"help" message.

* POV-Ray

Called the dkb-list for historical reasons (POV-Ray was based on
David Buck's "DKBTrace"), the list exists for users of POV-Ray and
associated products, on all platforms.

Subscription: listserv%TREARN...@vm.gmd.de
Body Text: subscribe dkb-l <Your full name>
Posting: DKB-L%TREARN...@listserv.gmd.de

* Rayshade

Mailing list for Rayshade users, mainly on UNIX platforms.

Subscription: rayshade...@cs.princeton.edu
Posting: rayshad...@cs.princeton.edu

* Radiance

Greg Ward, the author of Radiance has a distribution list of all
users. Register with him: gr...@pink.lbl.gov

* Imagine

For users of the Imagine 3d rendering and animation package for the
Amiga and, more recently, the IBM PC.

+ Subscription: list...@sjuvm.stjohns.edu
+ Body Text: subscribe imagine <first name> <last name>
+ Posting: ima...@sjuvm.stjohns.edu

* Toaster

This mailing list deals with the Video Toaster system for the Amiga.

Subscription: toaster...@bobsbox.rent.com
Body Text: subscribe <address> toaster
Posting: toa...@bobsbox.rent.com

* Lightwave

Lightwave is part of the suite of programs that come with the
Video Toaster system for the Amiga.

Subscription: lightwav...@bobsbox.rent.com
Body Text: subscribe <address> lightwave
Posting: ligh...@bobsbox.rent.com

* TrueSpace

This is a mailing list for users of trueSpace, maintained by
Shane Davison <dav...@cs.uregina.ca>.

Subscription: truespac...@caligari.com
Body Text: subscribe <address> truespace
Posting: true...@caligari.com

* 3D Studio

Autodesk's 3d modelling and rendering system for the IBM PC.

Subscription: 3dstudio...@bobsbox.rent.com
Body Text: subscribe <address> 3dstudio
Posting: 3dst...@bobsbox.rent.com

------------------------------

Subject 2.4 - Others

* CompuServe

The CompuServe Graphics Developers' Forum (GO GRAPHDEV) is the home
of POV-Ray (section 8 POV Sources and section 9 POV Images) as well
as other development projects including fractals, animation and
morphing. You can get information of joining CompuServe (in the US)
by calling (800) 848-8990. CompuServe access is now available in
other countries, including Japan and Europe.

* America On-Line

AOL also has a section (PCGRAPHICS) dedicated to POV-Ray support.

--
Andreas Dilger University of Calgary \"If a man ate a pound of pasta and
(403) 220-8792 Micronet Research Group \ a pound of antipasto, would they
Dept of Electrical & Computer Engineering \ cancel out, leaving him still
http://www-mddsp.enel.ucalgary.ca/People/adilger/ hungry?" -- Dogbert

Andreas Dilger

unread,
Feb 2, 1996, 3:00:00 AM2/2/96
to
Archive-name: graphics/raytrace-faq/part2

Last-modified: 1996/01/29
Posting-Frequency: every 10 days


This is part 2 of the comp.graphics.rendering.raytracing Frequently
Asked Questions list. The latest version of the FAQ is available via
anonymous WWW at:

http://www.cis.ohio-state.edu/hypertext/faq/bngusenet/top.html

under comp->graphics->rendering->raytracing. It is also available via
anonymous ftp at:

ftp://rtfm.mit.edu/pub/usenet/news.answers/graphics/raytrace-faq/

If you only have email, you can get it by sending email to:

<mail-...@rtfm.mit.edu>

with both

"send usenet/news.answers/graphics/raytrace-faq/part1" and
"send usenet/news.answers/graphics/raytrace-faq/part2"

in the body of the message (without the quotes).

(C) Copyright 1994 Andy Wardley


<a...@peritas.demon.co.uk>
(C) Copyright 1995, 1996 Andreas Dilger
<adi...@enel.ucalgary.ca>

------------------------------

Subject: 3 - Modelling Software

------------------------------

Subject 3.1 - MORAY

MORAY, by Lutz and Kretzschmar [CIS: 100023, 2006], is a shareware
modeller for PC's that directly supports POV-Ray 2.x primitives and
more. Registration is US $59 which will get you a protected mode
version, allowing full memory usage, plus all the usual support and
upgrade info.

MORAY is a program with which you can design scenes for the POV-Ray
raytracer to render. Contrary to normal scene design, with MORAY you
design the scenes graphically. Up to now it was pretty difficult to
imagine what the scene looked like, without laying it out on graph
paper, or doing many test renders. MORAY is like a graph paper, it
lets you place and change objects in wireframe while you see them.
MORAY then generates the text file that POV needs to read.

MORAY can thus also be used as a rapid prototype tool, to place
objects quickly and write the scene file. You can then edit scene
files to suit your needs, just like you have been doing up to now.

MORAY stores and works with POV-Ray primitives, as opposed to normal
CAD systems, which mostly convert all objects to triangle meshes or
similar polygon based formats when outputting. This ensures optimum
performance and image quality from the raytracer.

If you're a POV enthusiast and have access to CompuServe you should
check out the GRAPHDEV forum for the latest news and tips on using POV.
The RayTracing conference on PCGnet also carries lots of tips for POV.

The emphasis in designing MORAY was to be able to work as easily and
as graphically as possible. Most of the work can be done with the
mouse.

Three 2D views and a 3D view of your scene are visible on screen. You
can perform all transformations of the objects in the 2D views with
the mouse. The 3D view shows what the current camera will see, i.e.
how POV will raytrace it. MORAY allows you to:

* scale, rotate and translate an object interactively
* define cameras with which to view your scene
* view the scene in wire frame as POV-Ray will raytrace it
* specify the wire-frame complexity of on screen objects
* graphically place a bounding box around an object
* automatically create bounding boxes of any objects
* make nested CSG or composite objects
* assign textures from the TEXTURES.INC file to your objects
* define a new texture from within MORAY
* place imagemaps interactively on objects
* manipulate the control points of a bezier patch to create shapes
not easily created otherwise
* create bezier patch meshes
* create rotational, translational and tapering sweeps that are
output as smooth triangles
* copy complex nested objects
* create multiple copies of an object transforming each independently
* specify a region of the 3D view to render
* call POV-Ray from within MORAY to render scenes

MORAY requires at least a 386, a VGA card and a mouse, although this
is not recommended. The minimum usable system for larger scenes
would be a 486DX/25 and 4MB memory. The shareware version needs 2MB
EMS, but this limitation is removed in the registered version, since
it runs in protected mode.

You need to have POV-Ray 2.0 or greater is needed to render the scene.

------------------------------

Subject 3.2 - SCED

SCED is a constraint based scene editor written by Stephen Chenney
<sche...@franklin.cs.berkeley.edu>. Stephen also maintains a mailing
list for bug reports, patches, and early notification of new releases.

Sced is a scene modeller for UNIX and X. It runs on many UNIX platforms,
including Linux. It is being distributed as source code. The latest
version is always available at:
http://http.cs.berkeley.edu/~schenney/sced/sced.html
ftp://ftp.povray.org/pub/povray/modellers/sced/
ftp://ftp.cs.su.oz.au/stephen/sced/

+ An enhancement to SCED by Denis McLaughlin, called SCEDA, has all the
+ features of SCED, but also adds support for keyframed animation.
+ Animated objects have their position, rotation, and scale interpolated
+ smoothly across multiple keyframes via a (modified) spline function.
+ SCEDA is available at:
+ ftp://ftp.cyberus.ca/pub/sceda/

+ You can find out more about SCEDA at:
+ http://www.cyberus.ca/~denism/sceda/sceda.html.

Feature List:

* Cube, Cylinder, Cone, Plane, Sphere primitives.
* Full support for CSG, including CSG wireframes that look like CSG
objects.
* A constraint based editing interface, which supports the accurate
placement of object relative to other objects, and dynamic
constraint maintenance.
* Previewing using your favorite renderer.
* Arbitrary, dynamic view of the scene.
* Support for Radiance, RenderMan, POV-Ray, Rayshade, and VRML.
* Target renderer specific attributes - allowing the full range of POV
textures to be accessed, including the declaration of new textures
and the inclusion of files.
* Arbitrarily dense wireframes.
* A simple input file format.
* Support for arbitrary OFF format polygonal objects.
* Automatic compression and decompression of files.
* Spotlight and Area light sources.
* Removal of many restrictions on the editing of CSG objects,
including the ability to change the basic type of an object.
* Lots of bug fixes. This version is now very stable under Linux and
Solaris at least. The last very was regretably unstable.
* Lots of small improvements to things like previewing, selection,
handling of objects behind the eye and so on.

Tutorials are provided to introduce use of the interface.

The system has been tested on several platforms, and appears to be
easy to port to different systems. It REQUIRES X11 Release 5. Note
that POV 2.2 NEEDS TO BE PATCHED to use files created by SCED.
Binaries will soon be available for Linux and Solaris. Binaries for
other platforms are also desired.

Planned in the future:
* POV->Sced conversion program, for editing an old POV file.
* Bezier patch and arbitrary wireframe support.

------------------------------

Subject 3.3 - GUM

GUM is a solid and surface modeller that currently supports POV,
Polyray and Rayce and runs in MS Windows. The author is Lex van der
Sluijs <IO77...@student.io.tudelft.nl>.

GUM is DemoWare: the demo is yours and you have NO obligation to
register whatsoever, but there is a limitation: only 50 objects can be
saved. The price of the full program is f 150 (Dutch guilders) or
about US$85.

GUM stands for 'Grand Unified Modeller' which means two things:
* It will never be done.
* The fact that its internal data structure can accomodate all major
object types, that is solids (implicit, b-rep), surfaces
(parametric and polyhedral) and wireframe objects. (and yes, a
layout of its C++ class hierarchy takes many pages).

The current version is 0.91 (Jan 24th 1995), and can be found at:
ftp://ftp.povray.org/pub/povray/modellers/gum/
CAD BBS Holland (+31-3402-90287) where it is a free file
CompuServe, in the GRAPHDEV forum, thanks to Harry Rowe

I won't list the list of supported objects here since that would
become a bit long. Instead, some highlights:

* CSG evaluation, (wireframe representation of CSG Differences)
* 3D direct manipulation: 3D handles on objects like on the SGI
* support for trimmed surfaces (trimmed with a solid, that is) Polyray
can render these.
* real-time pan and zoom (non-real-time also possible)
* several renderers can be supported at once
* relatively advanced texture- (and other types of declaration)
handling, resulting in self-contained scene-files.
* heightfield reading for Targa files: see what you're doing
* Custom objects for external/not-yet-supported/huge objects
* support for 'extra special' features via the Header dialog (timer
variables, directional & textured lights, etc)
* the ability to find all used files used in the scene
* a robust RAW file reader
* Object library feature: use objects from other GUM scenes
* flexible FastDraw: Full, Skip(variable), Bounding Box. Static,
during viewport change/object dragging (multiple-viewport too)
* Automatic starting of the specified renderer, automatic starting of
your favourite imageviewer when the image is done

Some 'lowlights' (all of which will -naturally- be addressed):
* cumbersome installation procedure
* lack of sweeps
* lack of blobs
* cylinders, cones and paraboloids must be capped manually by
intersecting them with discs

System requirements: 386+387 @ 40 MHz with 4 Mb RAM. An 800x600
display is highly recommended, although 640x480 can be used. GUM plus
one renderer takes about 6 Mb on your harddisk.

Here are some frequently asked questions and their answers about GUM,
but first there are two things that should be brought to your
attention:
* there's already a FAQ in the manual, see the Contents topic. The
Q&A's here have popped up after the release of the program.
* most questions about usage of the program can be eliminated if you
do the Quick Start, also in GUM's help-file.

Q: I get a list of warnings every time I try to render or save
something, saying that some 'pages' could not be found. However,
all these 'pages' are POV/Polyray/Rayce keywords, such as 'marble',
'green' and 'diffuse'.

A: You need to move GUM.INI from GUM's directory to your WINDOWS
directory. If it's not there, extract a fresh GUM.INI from
GUM091EX.ZIP. In it are the keywords that have special meaning to
programs like POV, and without the file GUM can't discern between
references to other definitions (like using the normal 'Bumpy' in
'BumpyGlass') and keywords (such as 'red' and 'ior').

Q: When I try to start the program I get an error message saying that
CTL3DV2.DLL is not correctly installed.

A: More than one copy of this DLL could be found by Windows, which is
not allowed for this particular file, hence the cryptic error
message. You should find the most recent copy of it on your system,
move it to WINDOWS\SYSTEM and delete all others.

------------------------------

Subject 3.4 - Other Modellers

* Blob Sculptor
Blob Sculptor, by Alfonso Hermida, Steve Anger and Truman Brown
allows you to model shapes using blob primitives. Output is to RAW,
DXF, BLB (internal format), POV, Polyray, Rayshade and CTDS. In
addition, the Windows version, ported by Ronal Praver, supports NFF,
VideoScape and others. NeXTStep and Open GL ports are expected soon.


------------------------------

Subject: 4 - Utilities and Other Software

------------------------------

Subject 4.1 - Image Display/Conversion Programs

* DISP - an excellent viewing and post-processing utility for DOS.
Available on simtel and mirrors.

* IMAGEMAGICK - An X-Windows based image display program (source
distribution), that also allows simple editing of images, such as
color modification, scaling, rotating, text annotation, etc. PNG
format images are now supported by ImageMagick. Available at:
ftp://harbor.ecn.purdue.edu/pub/imagemagick.tar.gz
http://www.wizards.dupont.com/cristy/ImageMagick.html
(Cristy, 1995)

* NEOPAINT - A useful DOS shareware paint package (registration US
$45) for creating images, height fields, etc, or just touching up
finished artwork. Available from wuarchive and mirrors.

* NETPBM - A collection of command-line utilities for most platforms
(source distribution). Executables available for most other
platforms like DOS, OS/2, Linux, and others. NetPBM utilities
convert practically any format to any other by using a common
intermediate file format, as well as allowing quantization,
cropping, combining, blur, and many other effects. Available at:
ftp://wuarchive.wustl.edu/graphics/graphics/packages/NetPBM/
(Poskanzer et al., 1991-1994)

* PICLAB - An excellent package for converting and post-processing
images for DOS. (Crocker, 1990)

* QPV - The Quick Picture Viewer. A great utility for displaying and
converting images for DOS/Win systems. Formerly QPEG, QPV has been
improved, and has new features, such as the ability to read and
write PNG format images. (Fromme, 1995)

* XV - An X-Windows based image display program (source distribution),
with simple image editing facilities, such as color editing,
scaling, rotation, and also filter effects for blurring, edge
detection, and others. A patch is available for XV 3.10 to support
PNG images via libpng and libgz. (Bradley, 1995)


------------------------------

Subject 4.2 - Format Conversion Utilities

Much of the following sections area taken from Amanda Osbourne's
<a...@northshore.ecosoft.com> "Raytrace Utilities for DOS (and Windows)"
list. All are IBM PC based unless otherwise specified.

Various utilities for converting from one 3D file format to another:

* 3DSPOV - Reads 3d studio mesh files. Writes out to Raw, POV-Ray
(1 & 2), Vivid and Polyray. (Anger & Bowermaster, 1993)

* DEM2POV - This program (source distribution) converts US Geological
Survey (USGS) Digital Elevation Maps (DEM) to the TGA format
heightfields used by POV-Ray 2.2. Includes a large DEM file of the
region around the Grand Canyon. (Kirby, 1995)

* DXF2POV - DXF to POV-Ray 1 conversion program.
(Collins, Wells, Farmer & Gibeson, 1992)

* DXF2RAW - DXF to Raw conversion program.
(Coy, Barber, Daigle & Shiffman, 1992)

* DXF2V - DXF to Vivid conversion program.
(Coy, Barber, Daigle & Shiffman, 1992)

* DXF3DS - DXF to 3DS conversion program. (Yost/Autodesk, 1991)

* HUTIL101c - A set of utilities (source) for converting between
various POV-Ray heightfield formats (16-bit TGA, GIF, POT) as well
as OCT and Matlab 32-bit MAT files. In addition, it can combine
heightfields using arithmetic operators, join them together, scale,
and create spherical and cylindrical heightfields with triangle
meshes. (Beale, 1995)

* MRYPLY - Converts Moray files to PolyRay files.

* OBJ2ASC2 - Wavefront object to 3d studio ascii converter.
(Knight, 1993)

* RAW2PV - Excellent utility that allows the user to adjust the
level of smoothing to apply to raw data as it is translated to
POV-Ray (1 & 2.x), Polyray or Vivid 2. It can also add a camera
and light to the scene, making things fairly easy for the novice
user. (Anger, 1993)

* RAYL210 - Helpful utility to convert uLathe (an object creator
program for windows) files to RAW, POV-Ray 1 & 2.x or Vivid 2
format. (Koehler, 1993)

* TDDD2ASC - TDDD (Imagine) to 3D studio ascii file converter.
(Knight, 1993)

* WC2POV - Although wcvt2pov (Windows) started out converting 3D file
formats to POV-Ray, wcvt2pov has become a generic 3D file format
conversion utility, with support for importing 3d studio, Wavefront,
NFF, DXF, TrueType Fonts, RAW triangles and some other formats, and
exporting 3ds, asc, POV-Ray, NFF, DXF, VRML, Wavefront, Open GL 'C'
code fragments, RAW triangles, and some other formats. (Rule, 1995)

------------------------------

Subject 4.3 - Creation Creators

Utilities to aid in the creation of ray tacing objects:

* BOXER - Object generator for POV-Ray 1 (makes things like bathroom
tiles and such based upon user input). (Miller, 1993)

* BRANCH - Tree creator for POV-Ray 1. (Weller, 1992)

* CHAIN - Generates interlocking chain links for POV-Ray 1.0.
(Koehler, 1992)

* CM - CircleMaster utility for working with quadric spheres and
ellipsoids; writes output to POV-Ray 1.0. (Brown, 1992)

* COIL - Creates coiled objects for POV-Ray 1.0. (Kirby, 1992)

* COILV - Creates coiled objects for Vivid 2. (Kirby & Cox, 1992)

* CTDS - Connects a series of xyz dot coordinates. Though this may
not sound like much, this is an extremely helpful utility.
Supports POV-Ray, Vivid and Polyray. (Brown, 1993)

* FORM - All sorts of shapes can be generated with this program.
Form files consist of both shapes and commands (like twistx and
bend) and output may be POV-Ray 1, 2 or .plg. Interesting program,
complementary to LPARSER. (Rowbottom, 1993)

* FRACTINT - The ultimate fractals generator for DOS, X-windows source
code, and distributed with the Linux Slackware games disks. Great
for creating height fields, colour maps, viewing gifs or just
creating fractals. (The Stone Soup Group, 1990-95)

* FRGEN - Fractal Landscape (and other shapes too) Generator.
Though the program supports Vivid and POV-Ray 1 & 2 directly, by
selecting raw output you can smooth triangles out with RAW2POV to
create nice hills and dales. (Anger, 1993)

* GEODOME - Utility for generating geodesic domes. Output to
POV-Ray 2.x format as either facets or a mesh of pipes and joints.
IBM PC executable, with source included. (Wardley, 1994)

* GFORGE - Graphical Fractal Forgery (source, DOS exe). Generates
16-bit heightfields for POV-Ray, using a high-quality algorithm: the
IFFT of 1/f noise. File formats include PGM, PNG, POV TGA
heightfield, and Matlab bin. Several parameters give you control
over the appearance of the output, which can range from sand to
hills to mountains. Useful also for 2D textures; the image always
tiles perfectly. Now also supports craters. Source is available.
(Beale, 1995)

* LPARSER - L-system creator and mutator. This program is
particularly strong in the creation of organic looking forms. Many
example data files are included with the program. The language of
l-systems is not intuitive but the results can be truly stunning.
Outputs to DXF (both R12 and 3D faces), POV-Ray 2.x, RAW and
Renderstar VOL. A wire-frame viewer that reads .3DS, .RAW,
Fractint .RAY, ARE-24 .POL and Lparser/Renderstar .VOL files is
included. (Lapre, 1993)

* LV20POVID - Newer and more powerful than LV2POV, this program
reads an lviewer info file and generates data files in POV-Ray
(1 & 2.x) and Vivid formats. The program's main strength lies in
landscape generation. (van der Mark, 1993)

* TRMK - Terrain Maker (DOS) uses a triangle midpoint subdivision
algorithm to generate a variety of GIF heightfields.
(Jorgensen, 1995)

* PLANT - Fractal plant generator. Outputs supported are POV-Ray
(1 & 2), Polyray and CTDS (Connect the dots smoother).
(Bryerton, 1993)

* SUDS - Random positioning of lots of spheres (or other objects)
based on a variety of selections. (Farmer, Wegner & Schwan, 1994)

* TORPATCH - This DOS program creates a rope/wire object that passes
smoothly through supplied points out of a series of clipped tori.
Can also create a random tangle of wires. (Mackey, 1995)

* TWISTER - Utility that will create spirals, coils, etc., of
blobs, cubes or sphere. IBM PC executable with source, output to
POV 2.x format. (Wardley, 1994)

------------------------------

Subject 4.4 - Texture Editors

* CMAP - Interactive color map creator for POV-Ray.
(Lutz & Kretzschmar, 1993)

* TCE - The color editor for POV-Ray 1. (Farmer, 1991)

* TCEV - The color editor for Vivid. (Farmer, 1991)

* TEXMAKE - Early version of a utility to assist in texture
creation in POV-Ray 2.x. (Sigler, 1993)

------------------------------

Subject 4.5 - Animation

* AERO - AERO is a X-Windows based physical simulation environment
suitable for making complex, realistic animations. Objects
(including the camera) can be given properties like mass,
velocity, and acceleration, constraints like springs and dampers
can be specified between objects, and then AERO performs
collision detection, position, and orientation calculations.
Output is to POV-Ray 1.0 or 2.x scene files.
(Keller, Stolz, Ziegler, Braunl, 1995)

* AWKANI - AWK script to output POV-Ray animation data.
(Farmer, 1992)

* DTA - Dave's Targa Animator (DOS) converts .TGA and many other single
image format frames into .FLI's and .FLC's. (Mason, 1995)

* MPEG_ENCODE - MPEG_ENCODE (source distribution, also many
executables) can take images in PPM and JPEG formats (as well
as other formats, if a ...toppm converter exists) to produce
a fully compliant MPEG 1 animation. It is possible to run
the encoding on multiple processors. It is available in many
locations (see 2 - FTP Sites, Bulletin Boards, etc.)
(Rowe, et al, 1995)

* MPEG_PLAY - MPEG_PLAY (source distribution, also many executables)
displays MPEG 1 encoded animations on a large variety of systems.
(Rowe, et al, 1995)

* PPP - The POV and PolyRay Preprocessor allows scene files to be
created with conditional statements, loops, math functions,
vector math, and more to generate one or more scene files for
animation and complex object creation. (Wind, 1995)

* PVQUAN - PVQUAN (source) is a set of tools that allow you to create
.FLI creations on many platforms including UNIX and DOS. Source
code is provided and includes a hosts of useful functions like
quantisation, .GIF read, display, etc.

* RAYSCENE - Set of animation utilities, not raytracer specific.
(Jarik & Hassi, 1991)

* RTAG - Ray Tracing Animation Generator (not raytracer specific).
A powerful program with its own language which supports, amongst
other things, spline path generation. (Sherrod, 1993)

* SCEDA - SCEDA is a descendant of the SCED X-Windows modeller,
with enhancements to allow generation of multiple scene files
for an animation. (See also 3 - Modelling Software)
(McLaughlin & Chenney, 1996)

* SP - Spline paths for animations. Many output formats (POV-Ray,
Vivid, Polyray, 3DV, Wire 3D) and acceleration and deceleration
are supported as well. (Mason, 1992)

* ZOOM - Interpolates steps between two positions for POV-Ray 1.0.
(Brown, 1993)

------------------------------

Subject 4.6 - Miscellaneous Utilities

* POVMODE.EL - A mode for emacs to handle POV-Ray syntax. Available at:
ftp://ftp.povray.org/pub/povray/old-incoming/misc/pov-mode.el

* POVRAY TUTORIAL - The POV-Ray tutorial is a 100 page text tutorial
that you can print out and read in the comfort of your own home. It
covers almost all of POV-Ray's features, including height fields,
realistic spotlights, and image maps. You can either jump to the
section that interests you or follow through from the beginning to
see the complete complex scene through to completion. The tutorial
is designed for beginners and more advanced artists alike. It is
distributed free in Windows, Mac and postscript formats currently at:
ftp://ftp.povray.org/pub/povray/old-incoming/utilities/pvt100.zip

------------------------------

Subject: 5 - Further Information and Resources

------------------------------

Subject 5.1 - On-line Resources

* FAQs
All of the FAQs in the USENET heirarchy that are posted to the
news.answers newsgroup (as all FAQs should be) are archived at:
ftp://rtfm.mit.edu/pub/usenet/news.answers/

They are also converted to HTML format and made available at:
http://www.cis.ohio-state.edu/hypertext/faq/bngusenet/top.html

* Ray Tracing News
Eric Haines <er...@eye.com> has put together a phenomenal amount of
information on ray tracing. This he combines into his Ray Tracing
News (RTNews). They are a wealth of information and contain
articles, sofware reviews and comparisons, book reviews and lists of
everything and anything to do with ray tracing. They are available
from many sites in text and/or HTML format, including:
ftp://ftp.princeton.edu/pub/Graphics/RTNews/
http://wuarchive.wustl.edu/graphics/graphics/ray/RTNews/html/
http://www.povray.org/rtn/

Eric's ray tracing and radiosity bibliographies as well as an
FTP list are available at:
ftp://ftp.princeton.edu/pub/Graphics/Papers/

* Ray Tracing Bibliogaphy
Rick Speer <sp...@crl.com> has also done a lot of work in bringing
together articles on ray tracing. He maintains a cross-indexed ray
tracing bibliography of over 500 articles from 1968 to the present.
These include papers from all Siggraph, Graphics Interface,
Eurographics, CG International and Ausgraph proceedings. All
citations are keyworded and cross-indices are supplied by author and
keyword.

The bibliography is in the form of a 41 page postscript file which
is held at many ftp sites as "speer.raytrace.bib.ps.Z":
ftp://wuarchive.wustl.edu/graphics/graphics/bib/RT.BIB.Speer/
ftp://karazm.math.uh.edu/pub/Graphics/
ftp://nic.funet.fi/pub/sci/papers/graphics/

Ian Grimstead <I.J.Gr...@cm.cf.ac.uk> has also collected
together a large collection of over 360 pages on-line of ray tracing
papers. It is accessible via the World-Wide Web and has links to
other on-line papers and documentation at:
http://www.cm.cf.ac.uk/Ray.Tracing/RT.Bibliography.html

Ian also maintains a web page of links to other WWW ray tracing
pages. You can also add your own links to ray tracing pages that
you maintain at:
http://www.cm.cf.ac.uk/Ray.Tracing/

* Ray Tracing Abstracts
Tom Wilson <wil...@cs.ucf.edu> has collected over 300 abstracts from
ray tracing related papers and books. The collections is available
as plain ascii, with Latex and troff formatting programs included.
It is available as "rtabs.*" from many sites.

* Graphics Resources List
The Graphics Resources List contains a wealth of information on all
sorts of computer graphics and visualization information. It has
info on mailing lists, plotting packages, ray-tracers, other
rendering methods, etc. It is available on comp.graphics,
comp.answers or archived at various sites. The official archive is
ftp://rtfm.mit.edu/pub/usenet/news.answers/graphics/resources-list/part1
ftp://rtfm.mit.edu/pub/usenet/news.answers/graphics/resources-list/part2
ftp://rtfm.mit.edu/pub/usenet/news.answers/graphics/resources-list/part3
ftp://rtfm.mit.edu/pub/usenet/news.answers/graphics/resources-list/part4
ftp://rtfm.mit.edu/pub/usenet/news.answers/graphics/resources-list/part5
ftp://rtfm.mit.edu/pub/usenet/news.answers/graphics/resources-list/part6

* Paper Bank Project
Juhana Kouhia <jk8...@cs.tut.fi> has collected together various
technical papers in electronic form. Contact him for more
information.

------------------------------

Subject 5.2 - Other Newsgroups

Note that because of news group reorganization, the previous
raytracing news group, comp.graphics.raytracing, has disappeared. The
new group is comp.graphics.rendering.raytracing.

Some other newsgroups that may be of interest to you are listed below.
Most of these have FAQs of their own which are available at:
ftp://rtfm.mit.edu/pub/usenet/news.answers/ [18.70.0.209]
http://www.cis.ohio-state.edu/hypertext/faq/bngusenet/top.html

- comp.graphics.algorithms
- comp.graphics.animation
- comp.graphics.misc
- comp.graphics.apps.alias
- comp.graphics.apps.lightwave
- comp.graphics.apps.wavefront
- comp.graphics.packages.3dstudio
- comp.graphics.rendering.renderman
- comp.graphics.visualization
- alt.graphics.pixutils

------------------------------

Subject 5.3 - Books

Title: Ray Tracing Creations
Authors: Drew Wells and Chris Young
Publisher: The Waite Group
Year: 1993
ISBN: 1-878739-27-1

This book has been written by Drew Wells and Chris Young, two of the
original developers of POV-Ray, as a user and reference manual for
POV-Ray. Coming in at 573 pages, it's an excellent publication with
literally hundreds of stunning colour and monochrome pictures. The
only drawback with the book is that it deals with POV-Ray version 1.0
which is a little dated now that version 2.2 is out, but it is still a
very worthwhile investment for any POV-Ray user.


Title: Ray Tracing Worlds with POV-Ray
Authors: Alexander Enzmann, Lutz Kretzschmar, and Chris Young
Publisher: The Waite Group
Year: 1994
ISBN: 1-878739-64-6

Raytracing Worlds with POV-Ray is written with the intermediate to
advanced POV-Ray user in mind. This book comes with POVRay V2.2,
Moray, and several additional tools for MS-DOS on diskette. It
assumes you have a basic knowledge of POVRay, which you can easily get
by reading the POVRay documentation. An review of the book is
available at:
http://www.povray.org/povzine/povzine1/raytrace.html


Title: Adventures in Ray Tracing
Author: Alfonso Hermida
Publisher: Que Corp.
Year: 1993
ISBN: 1-56529-555-2

This book looks at Alexander Enzmann's ray tracer, Polyray
(see 1 - Ray Tracing Software), and the author's own modelling system,
POVCAD which runs under Microsoft Windows. The two work well together.
The content of the book is good and, as in the previous book, there
are many excellent illustrations and pictures.

There are a few errors in the book, but Alfonso has produced an
errata list which is available from:
ftp://wuarchive.wustl.edu/graphics/graphics/books/erratas/


Title: Photorealism and Ray Tracing in C
Authors: Christopher Watkins, Stephen Coy, Mark Finlay
Publisher: M&T Books
Year: 1993
ISBN: ????

Provided with this book is source code for a ray tracer called Bob
which is a subset of Stephen Coy's full-blown ray tracer, Vivid
(see 1 - Ray Tracing Software).


Title: Making Movies on Your PC
Authors: David K. Mason and Alexander Enzmann
Publisher: The Waite Group
Year: 1993
ISBN: 1-878739-41-7

Focusing on animation, this book is by David K. Mason, author of many
utilities including DTA - Dave's Targa Animator, and Alexander
Enzmann, author of Polyray. These tools, and others, are used to show
how animations can be created on a PC. It's a 210 page book that is
laid out well with ample illustrations.


Title: An Introduction to Ray Tracing
Authors: Andrew Glassner (ed)
Publisher: Academic Press
Year: 1989
ISBN: 1-12-286160-4

An Introduction to Ray Tracing has its main focus on the programming
techniques, implementation, and theoretical concepts in writing a ray
tracer. It has been described as one of the two required books for
ray tracing programmers (the other being Object-Oriented Ray Tracing
in C++ by Nicholas Wilt) . It contains chapters from many of the
pioneers of ray tracing. Eratta is available at:
http://wuarchive.wustl.edu/graphics/graphics/books/erratas/IntroToRT


Title: Object-Oriented Ray Tracing in C++
Author: Nicholas Wilt
Publisher: John Wiley & Sons
Year: 1993
ISBN: 0471-304-158
US Price: $36.95

This book takes the reader through many issues involved with the
development of a ray tracer in C++. The last section of the book
deals with OORT, a class library for ray tracing. It does not
implement any input language or user interface but uses C++ calls to
the library. This is intuitive, due to the nature of C++, and
extremely powerful as all the normal constructs of C/C++ such as
loops, conditionals, etc., are available.

It's definately a programmer's book and some knowledge of graphics
programming is assumed. Because of this, the nature of the book is
quite technical and can be hard going. Eric Haines sums it up well:

"If you want to make pretty pictures, get POV, Polyray, Rayshade, etc.
If you want to look at some nice C++ code for a vector & matrix
library, etc, check this code out."

The code is available from:
ftp://wuarchive.wustl.edu/graphic/graphics/ray/
ftp://ftp.funet.fi/pub/graphics/packages/ray-tracing/oort/

------------------------------

Subject 5.4 - Image Libraries

The POV-Ray home site has a good collection of ray traced images. The
site maintains a "Hall of Fame" for outstanding images, as well as an
archive of images submitted to the monthly ray-tracing competition
held each month on comp.graphics.rendering.raytracing. Have a look at:
ftp://ftp.povray.org/pub/povray/Hall-Of-Fame/
http://www.povray.org/hof/
ftp://ftp.povray.org/pub/competition/
http://www.povray.org/competition/


A CD is available containing raytraced images, programs and utilities.

Title: L'ATELIER D'ATON (2nd Edition - October 1993)
Publisher: D.P. Tool Club
59657 Villeneuve d'Ascq
B.P. 745
France
Contact: Nicolas Kelemen - CompuServe 100012,1410

------------------------------

Subject 5.5 - Texture Libraries

There is a library of building related textures (bricks, stone, etc.),
for use as image maps at:
ftp://wuarchive.wustl.edu/packages/architec/Textures/

------------------------------

Subject: 6 - Frequently Asked Questions

Now that you've been blasted with lists of FTP sites, utilitites,
software, books, etc., etc., the only questions you could possibly have
left to ask are those that...erm...aren't about FTP sites, utilities,
software or books, I suppose. So this section attempts to answer all
the other questions that don't fit in above.

At the moment, the list is fairly short, but then the group hasn't been
going that long. As more questions get added, I'll no doubt re-organise
and categorise the questions better, but for now you'll have to take
them as you find them.

------------------------------

Subject 6.1 - "Who is..."

This section looks at some of the ray tracing artists and people who
are particularly well known for their work, be it images or software.
The list is in strict alphabetical order as I don't fancy the task of
trying be subjective about who's pictures are better than who's.

A VERY IMPORTANT POINT: A lot of these people have to pay for their
Email and 'net access. DO NOT send them large images or other posts
without checking with them first. Certain members of the POV team
have recently had some pretty hideous costs (like $30 for 1 mail item)
because of this. (Was that OK, Dan?)

* Eric Haines
Eric A. Haines <er...@eye.com> has probably done as much as anyone
to make ray-tracing as understandable and accessible as it currently
is. His many, many hours compiling the Ray Tracing News helped many
people understand and develop ray tracing software, as well as serve
as a forum for discussion between those interested in the art.
(See 5 - Further Information and Resources).

* Truman Brown
Truman Brown <7147...@compuserve.com> is particularly well known
for his "woild" series of images. He is a self-confessed "Obsessed
Programmer / trace-aholic" and has written a range of very useful
utilities, including Connect The Dots Smoother (CTDS), Circle Master
(CM) and its companion, HYPE.

He has an understanding wife but his kids wish he didn't hog the PC
so much. His utilities are available from most FTP sites and you
can check out some of his images at:
ftp://ftp.povray.org/pub/povray/Hall-Of-Fame/
http://www.povray.org/hof/

* Andrew Denton
Andrew H Denton, or AHD, <guar...@netcom.com> is a professional
juggler and ray tracing artist. He uses Lightwave on 2 040 Amigas
and "lots of other toys". Dragons feature heavily in his artwork
and some of the pictures are truly stunning. Some of his images (no
models) are at:
ftp://icecube.acf-lab.alaska.edu/pub/dragons/graphics/new/ahd/

* Dan Farmer
One of the original POV-Ray development team, Dan
<70703...@compuserve.com> or <Dan.F...@f524.n125.z1.FIDONET.ORG>
has created some amazing images including the stunning "frosty.gif".
Dan explains how he did it:

"The image was done in POV-Ray. It's really quite simple. The face
is a freely available dataset produced by Mira Imaging... I'm sure
it exists on the net somewhere. The fractal shape is done with
Fractint, using the 16 bit continuous potential features. It's an
inverted Mandelbrot set. The silver texture is Silver1 in
textures.inc. The sky is the usual bozo, but it's mapped onto a
plane, not a sphere. Floor is an imagemapped plane. That's all
there is to it!"

Frosty is at ftp://ftp.povray.org/pub/povray/Hall-Of-Fame/frosty.gif.
+ The Mira dataset is at ftp://ftp.povray.org/pub/povray/scenes/mirpov.zip

+ Unfortunately, Dan rarely releases his source code any more due to
+ certain unscrupulous sorts using his images for commercial purposes
+ without payment or even permission. Luckily, he has made the scene
+ file for this image available on the POV-Ray CD-ROM which is also
+ available online (see 1 - Ray Tracing Software).

Dan is often around on the group and is very unselfish in spending
time answering questions.

* Mike Miller
If you ever need inspiration to see what can be done using POV-Ray,
a piece of graph paper and a pencil, then look at some of Mike
Miller's <7035...@compuserve.com> images. His pictures never fail
to impress and he has undoubtedly produced some of the best pictures
ever created with POV-Ray. Mike created many of the demo scenes
that come with POV-Ray and he is responsible for the excellent
textures in "stones.inc".

The cover story of the January 1994 IEEE Computer Graphics and
Applications is entitled "Mike Miller's Many Hats" and looks at his
work and includes many of his pictures.

You can find his images and scene files on many sites. A good one to
start with is ftp://ftp.povray.org/pub/povray/Hall-Of-Fame/ or
ftp://ftp.povray.org/pub/povray/images/.

Particular ones to look out for are benz9.jpg (model of a 1928 Mercedes
Benz), camera.jpg, bug1.gif, etc., etc., the list goes on.

* Ken Musgrave

Ken Musgrave <musg...@seas.gwu.edu> was called "the first true fractal-
based artist" by Benoit Mandelbrot, the father of fractals. His work
shows the artistic side of what can be done with mathematics and
inspiration. Many have seen his image "Blessed State" inside the
cover of "Computer Graphics, Principles and Practice" by Foley &
van Dam, the authoratative computer graphics book. He has an excellent
exhibit of his works available on the WWW at:

http://www.seas.gwu.edu/faculty/musgrave/art_gallery.html

Ken is currently applying his skills to creating an entire world model
with algorithmic principles. Some examples of the excellent
landscapes for which he is known are also available.

* Andy Wardley

Andy was the creator and previous maintainer of the c.g.r FAQ, until
mid 1994. After a hiatus of several months while he changed jobs, he
is now again a member of the raytracing community. Due to time
constraints, he is no longer able to maintain the Ray Tracing FAQ, but
I'm sure everyone is greatful for the work he did in setting up this
FAQ.

------------------------------

Subject 6.2 - "This picture doesn't trace."

I know it might sound a bit obvious, but have you read the error message
and tried to understand it? Did you look in the manual? Still nothing?
I know I sound cynical, but it's not uncommon for people to have
something go wrong and then post straight to the 'net without even
*trying* to figure out what went wrong. A little patience and thought
will solve the problem a lot quicker.

Here's some common problems:

* POV-Ray versions
A lot of people get fooled when trying to trace old POV-Ray code
with a new version. Use the -MV1.0 option or use #version in the
code to get the parser to treat it as old code. You may find that
you have to change any references to "shapes.inc" to "shapes.old".

The POV-Ray docs can help you out here. What do you mean "I haven't
got the docs"? Go get them. (See 1 - Ray Tracing Software)

* Include files
Have you checked that you've #included any include files that your
scene requires? Include files tend to define colours, textures or
objects that your scene may use. Make sure you've told the ray tracer
where to look for include files. For example, POV-Ray uses the -L
option to specify the directory where include files are, eg.

-L/home/adilger/povray/include

The POV-Ray docs can help you out here. What do you mean "I haven't
got the docs"? Go get them. The same applies if you haven't actually
got the files (see 2 - FTP Sites, Web Sites, Bulletin Boards, etc.)

------------------------------

Subject 6.3 - "I traced my picture, but I can't see anything."

If the picture is completely dark, there are several things you can check:

* Have you added any light sources?

* Are the light sources blocked by anything? (This is a favourite of
mine - I put in a large sphere for the sky and then add or move lights
*outside* the sky sphere. Where did the lights go?)

* Where are you looking? Are you sure your camera isn't inside an object?

* Have you applied textures to your objects. If you haven't, you might
find that your ray tracer defaults your object to be black.

Have you actually put anything into the picture? This isn't as silly as
it sounds. If you #declare on object (POV-Ray, again) like this:

#declare my_object=
union {
sphere { <0, 0, 0> 1 }
cylinder { <-2, 0, 0> <2, 0, 0> 0.5 }
}

Then you have just told the ray tracer that when you refer to "my_object",
you actually mean a union of a sphere and a cylinder as shown. To use
the object, you must explicitly put it in:

object { my_object }

------------------------------

Subject 6.4 - "I traced my picture, but the output is garbage."

Did you specify the correct output file format? Most ray-tracers have
several options for output file formats. If you haven't explicitly
specified the output format, there's a good chance it's not what you
want it to be. Also note that giving a file a specific extension
(like .TGA) does not necessarily mean it is that format of image.
Some image display programs use the file extension to determineand the
file contents, so if you call the file output.tga, and it's actually a
PNG image, your display program may complain that the TGA file is
corrupted.

------------------------------

Subject 6.5 - "How can I view these pictures?"

If you're using UNIX, you can use XV which is available as a source
distribution from many sites, or ImageMagick, again available on many
sites. It should be noted that XV v3.00, which is installed at some
sites, does not display TGA files, although XV v3.10 and ImageMagick
do.

If XV and/or ImageMagick do not support a particular image format you
have, it probably doesn't actually exist :-). However, if you need to
handle large numbers of images in batch form, or if you don't have an
X windows display and you want to manipulate images (but not
necessarily view them), chances are that the netpbm package is what
you need. Netpbm is a command line utility, and can converting images
from practically any format to any other, but it does not display the
images themselves.

If you're on a PC and using DOS, you'll probably want to get either
QPV or PICLAB to do the displaying. For Windows users, lview seems to
be a popular display/editing program, and for OS/2 there is PMJpeg,
which is an OS/2 port of lview. There are kegs-o-megs of PC image
viewers at most ftp sites, so take your time and find one you like.

These packages are available in countless locations on the Internet
(see 4 - Utilities and Other Software).

------------------------------

Subject 6.6 - "Rotating/scaling this object doesn't work properly."

With most ray tracers, rotating on object in a given direction rotates
it around the axis *not* around its own centre. If your object is
centred on the X axis and you rotate it in the X direction, it will
spin. However, if it is some distance from the axis and you rotate
it, it will "orbit" the X axis, tracing a circle with a radius equal
to the distance of the object from the axis.

Confused? Think of the Earth spinning on it's axis. It doesn't go
anywhere because it is centred on its axis (ignoring rotation around
the Sun). The moon, however is some distance from the Earth's axis
and as it rotates around that axis, it travels through space, orbiting
the Earth.

To work out which way something will move, you need to know if your
ray tracer uses a left or a right handed co-ordinate system. POV-Ray,
for example, uses a left handed system. To work out which way an
object will turn, point your thumb in the positive direction of the
axis you're rotating in and the way you fingers curl indicate the
direction of positive rotation. The hand you use to do this depends
on your ray tracer; left-handed, use left hand, right handed, use
right.

The same thing goes for scaling. If your object is already some
distance away from the origin, that distance will also get scaled.
For example, if you have a sphere 2 units away from the origin, with a
radius of 1 and you scale it by 2, the radius will now be 2 *and* the
distance from the origin will be 4.

------------------------------

Subject 6.7 - "Where can I find model data for..."

The former Avalon site has been closed down, and the Avalon model site
has been moved to Viewpoint, a commercial model vendor, as of 07/95.
It is the promise of Viewpoint that the Avalon data remain freely
available to all. Avalon is now located at:
ftp://avalon.viewpoint.com/avalon/ or
http://www.viewpoint.com/avalon.html or
ftp://ftp.povray.org/pub/mirrors/avalon/ is a mirror.

Avalon is probably the best site you'll find for free 3D model data.
However, the home page at Viewpoint also has pointers to their free
and commercial models if you can't find what you need at Avalon.
Another commercial model vendor on the net is MeshMart at:
http://cedar.cic.net/~rtilmann/mm/

(See also 2 - FTP Sites, Web Sites, Bulletin Boards, etc.)


------------------------------

Subject 6.8 - "Can I post binaries/images to this group?"

In a word, NO. The group is part of the comp.graphics hierarchy which
should be, and is, strictly non-binary. The reason for this is that
uuencoded binaries tend to be very large. By restricting binary
postings to the comp.binaries and alt.binaries hierachies, those sites
who do not want to carry large volume groups can easily ignore
anything under these two streams.

Remember that most sites pay to transfer and store news and if they
find that comp.graphics.rendering.raytracing is getting too expensive,
they can just stop carrying it. That is their right and priviledge.
Also remember that many individuals download this group via modems and
pay for every byte. They tend to get a bit annoyed when they have to
fork out lots of money to download stuff they might not even want.

But what if you're really desperate to share with us your latest ray
tracing you've done depicting a mutant star camel exploding in a super
nova while naked dancers melt into a checkered floor? (the checkered
floor always turns up sooner or later). Great! I'm sure we'd love to
see it, you should post it to news:alt.binaries.pictures.misc or upload
it to ftp://ftp.povray.org/pub/povray/images/. If you're posting it
you should remember to uuencode it and split it into small (less than
64k) parts. Remember to put an informative title on it like:

RAY TRACING: MUTANT.GIF: mutant star camel scene, part 1 of 6

and include a text posting (part 0 of n) that describes the picture,
states what format it's in (.gif, .jpg, etc.), what size it is, how
many colours, and anything else you want to mention. The more you
put, the better.

You can then post a message to news:comp.graphics.rendering.raytracing,
along with a few lines saying "I've just posted this image to
alt.binaries.pictures.misc". BTW, ray tracing pictures generally get
a good response over in a.b.p.m and you'll often see request for them
in news:alt.binaries.pictures.d (the discussion group).

If it's a utility you're posting, it should go to alt.binaries.misc
instead of news:alt.binaries.pictures.misc, but the same process applies.

The other alternative is to upload the picture or utility to an ftp
site and use news:comp.graphics.rendering.raytracing to announce it in
the same way.

------------------------------

Subject 6.9 - "What does this mean..."

Some ray tracing and related terms you might come across:

* CSG (Constructive Solid Geometry) - A term describing ways in which
you can build up complex shapes from simple primitives like cubes,
speres, and cylinders. By combining the primitives in different
ways, namely adding them together (union), taking one away from the
other (difference) or getting the part where they intersect
(intersection) you can make small building blocks, which can in turn
be used to make more complex CSG objects.

* Height Field - A height field can be thought of as a 3 dimensional
bar graph. It is a grid of data where the value at any point
corresponds to the "altitude" of that point. Height fields are
typically stored as images with the lighter areas being higher, and
the darker areas lower. Heightfields are usually used for flat
surfaces, but can also be wrapped around cylinders and spheres in
some software packages.

* Radiosity - Most ray-tracers use an empirical lighting model - that
is the parameters specified for lights and objects do not really
correspond to physical properties, but are selected to make things
look good. Radiosity calculates the reflections and lighting
between all objects in the scene, and gives a more realistic
rendering of the scene. This method is very good at representing
the diffuse lighting in a scene, while ray-tracing is better at
handling the reflection. In some renderers, both techniques are
used to give spectacular results. Needless to say, radiosity is
even more computationally complex than ray-tracing.

------------------------------

Subject 6.10 - "What is the difference between rendering and ray-tracing?"

Ray tracing *is* rendering. But then so is z-buffer rendering,
scanline rendering, etc. Ray tracing is just another algorithm used
to render (i.e. "paint") pictures.

------------------------------

Subject 6.11 - "When will POV-Ray 3.0 come out?"

The only possible answer is: "When it's finished." Currently this
looks to be spring 1996, but it could be at any time. POV-Ray is a
volunteer effort, so the authors also have other things to do. Please
be patient. There will be no doubt about when it has arrived, so I'm
+ sure you didn't miss it. For a complete source of information about
+ POV 3.0, have a look at both:
+ http://www.povray.org/povray3.html
+ http://www.ahoynet.com/~bradg/pov3w.html

------------------------------

Subject 6.12 - "Where are the .inc files for POV-Ray?"

The .inc files in question (textures.inc and colors.inc) are included
in the documentation files, which should be at the same location as
the POV-Ray source or executable files. These files were deliberately
left out of the other packages so you would HAVE to get the
documentation. This will save everybody from answering a lot of
questions later. Read the documentation. It is good. How do you
propose to create anything without the documentation?
(See 2 - FTP Sites, Web Sites, Bulletin Boards, etc.)

------------------------------

Subject: 7 - Roll the Credits

Special thanks go to Eric Haines <er...@eye.com> for his help and the
wealth of information he has provided both directly and in Ray Tracing
News, FTP lists, etc.

Thanks also to all those people who maintain other lists,
bibliographies, FTP sites, or have provided me with specific
information, told me where to look, produced mini-faqs (thanks John) or
have just posted answers to the group:

John Beale <be...@leland.Stanford.edu>
Nick Fotis <nfo...@theseas.ntua.gr>
Jim Grimes <ji...@bongo.jpl.nasa.gov>
Ian Grimstead <I.J.Gr...@cm.cf.ac.uk>
Laszlo Herczeg <las@light-house@whome.planix.com>
Chris W. Morris <c...@hopper.itc.virginia.edu
Frank Neumann <Frank....@arbi.informatik.uni-oldenburg.de>
Bjorn-Kare Nilssen <bjo...@oslonett.no>
George Kyriazis <kyri...@mistral.esd.sgi.com>
Daniel Palermo <pal...@crhc.uiuc.edu>
Harry Rowe <Harry...@wedowind.meaddata.com>
Heinz Schuller <hei...@delphi.com>
Rick Speer <sp...@crl.com>
Greg Ward <gr...@pink.lbl.gov>
Andy Wardley <a...@peritas.demon.co.uk>
Oliver Weyand <chb...@nyx.uni-konstanz.de>
Marius Watz <mar...@ifi.uio.no>

Finally, some king-size thanks to all those people out there who have
developed, and continue to do so, all the ray tracing software and
utilities that keep us so occupied. Wives, girlfriends and children may
disagree on this point, but thanks anyway.

Special awards in this category go to Dan Farmer
<70703...@compuserve.com> who wins the Award for "Not-Only-Doing-All-
His-POV-Team-Stuff-But-Also-Answering-Lots-of-Questions-And-Being-An-All-
Round-Mr.-Nice-Guy", and Chris Cason <Chris...@oaks.com.au> who gets
the coveted "Also-Does-His-POV-Bit-Especially-Being-Admin-of-the-POV-Site-
And-Answering-Questions-As- Well-And-Making-the-POV-Ray-CD-Too".

Sorry if I've forgotten anyone. Thanks anyway.

------------------------------

Subject: Epilogue

You may have noticed one or two gaps in the FAQ or spotted a glaring
error, or just thought of something that I really should have mentioned.
If that's the case and you can provide some info or corrections, then
let me know and sort it out.

Well here you are at the end of the document, and your trace is still
only half done. You've probably got time to walk the dog before it's
finished...

Happy Tracing.

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