[comp.archives] [graphics] Re: Shading Language

jonas-y@isy.liu.se (Jonas Yngvesson) (03/20/91)

Archive-name: graphics/rendering/sipp/1991-03-19
Archive: isy.liu.se:/pub/sipp-2.0.tar.Z [130.236.1.3]
Original-posting-by: jonas-y@isy.liu.se (Jonas Yngvesson)
Original-subject: Re: Shading Language (was: AT&T Pixel machine)
Reposted-by: emv@msen.com (Edward Vielmetti, MSEN)

po0o+@andrew.cmu.edu (Paul Andrew Olbrich) writes:

>An easy way to do this is to have your renderer be a big archive or
>library, and then describe a scene to be rendered using a language such as C.
>(With a RenderMan-ish syntax.)  The scene description is then compiled and 
>linked to the rendering library, forming a big executable which generates 
>your image.  
...
>Does this make sense? ... (I'm a little incoherant at the moment after pulling
>an all-nighter... my apologies.)

Sure does. 

>PS.  If anyone is interested I can answer questions about how to implement
>something like this.  I wrote a ray tracer that works this way with CSG,
>object heirarchies, K/K bounding slabs, and shading language support.
>Oh another benefit is when I do animation with this, I can generate
>a single executable that generates all the frames based on a time 
>parameter.  Since scene descriptions are all C, I can throw in splines or
>make up silly functions to control movement.  I did a short physical
>simulation, and wrote that right into the scene description.  To generate
>the scene for a given frame, it would simulate the dynamics up till
>that frame.  This saves a lot of disk space.
>This probably should be done in C++, I think, to be truely nifty.

You can also pick up the SIPP rendering library from some ftp site. It is
a library for rendering objects built of polygons using a scan line z-buffer
and Phong shading. It uses just this approach. Each surface has a pointer
to the shading function it should be shaded with.

It is for example availiable from isy.liu.se (130.236.1.3) as 
pub/sipp-2.0.tar.Z

--Jonas
-- 
------------------------------------------------------------------------------
 J o n a s   Y n g v e s s o n
Dept. of Electrical Engineering	                         jonas-y@isy.liu.se
University of Linkoping, Sweden                   ...!uunet!isy.liu.se!jonas-y