########################################################################
			  MTV RAYTRACER*
	     written by Mark Terrence VandeWettering
		      markv@cs.uoregon.edu
########################################################################
* Well, I have had the initials since 1964, Music Television can't say
  that :-)

This represents the second formal release of the MTV Raytracer.
It was written to help me understand how raytracing works, to
generate cute images, and generally because I like to program. 
Feel free to use it for any purpose, I am releasing it into the 
public domain.

The input format to this ray tracer is called "NFF" or Neutral File
Format, which was invented by Eric Haines' for his Standard Procedural
Database.  The SPD was designed to allow programmers to test their
raytracers on databases of varying sizes.  While not the end-all to
object file formats, it has served me well.  If you wish to change the
input file to something else, you probably only need to change the
parser in "parse.y", not any of the other code.

NFF supports the following primitives:
	spheres
	cylinders
	cones
	polygons
	polygonal patches (normals are interpolated from corner points)

The MTV raytracer supports all of these primitives, with the minor
limitation that polygonal patches must be triangles (have only three
vertices).  I am sure some clever person can convert patches with more
sides to triangles, I haven't found the need yet.

The output from the raytracer is very simple, and not directly tied to
any specific device.   It consists of a single line, with format in 
C scanf style of "%d %d\n", which gives the resolution of the image.
It is then followed by x*y sets of (red green blue) bytes.  We have 
pretty unstandard hardware here,  (I convert these to Utah Raster
Toolkit form and then filter that to display on a Tek4115) but I do 
maintain an archive of source which has been sent to me for this
purpose.  More below--

By the time you read this, this raytracer should be available via
anonymous ftp from drizzle.cs.uoregon.edu.  I will try to archive
source code for displaying the ".pic" files, as well as interesting
objects that I run accross.  Filters already exist to display images on
suns, to convert to PostScript and Impress, as well as X bitmaps Also
available is Eric Haines' SPD source code, so you can generate your own
fractal spheres, mountains, gears etc.

By placing this in the comp.sources.unix, I hope to get this to more of
the people who have requested it.  I will entertain e-mail with
questions, and even requests for the source code, but remember that I am
a grad student only, and have limited time.  If it takes me a long time
to reply, send mail to me again.

Thanks must go to Eric Haines especially, whose e-mail conversations
have been interesting and fruitful.  Also thanks to the numerous
authors whose research into raytracing has seen implementation in this
raytracer, and have provided a host of ideas about image synthesis.
Also thanks to Jeff Eaton and David Koblas, whose criticism and sense of
competition drove this poor hacker to write a better program than he
could have without them.

Ta Ta For Now...
Mark VandeWettering