[comp.sys.ibm.pc] Auto-CAD file format questions

lansd@eecg.toronto.edu (Robert Lansdale) (05/11/89)

	For the last little while I have been writing a 3d graphics package
that runs on SUN workstations. It supports a number of primitives (polygons,
spheres, bezier patches, etc) and rendering algorithms. Due to a lack of
3d model descriptions, I recently added the capability to load CAD-3D files
(Atari-ST CAD program) since there is a number of good objects in the public
domain. 

	As the CAD-3D loader was successful, I started wondering whether
I could load Auto-CAD files too (there are a large number of object files on
local BBSs). I absolutely know nothing about the program (ok, I've played
with it a bit), so I thought maybe some Usenet readers may be able to answer
my questions:

	1) Are Auto-CAD object/model descriptions in terms of simple lines
		or polygons? I can handle lines, but require polygons for
		shading and zbuffering.

	2) Does anyone have a description of the Auto-CAD file format? 

	Any pointers on this subject or suggestions would be welcome.


-- 
CSNET: lansd%eecg.toronto.edu, ARPA: lansd%eecg.toronto.edu@relay.cs.net
Electrical Engineering Computer Group, University of Toronto.