Path: utzoo!mnetor!uunet!lll-winken!lll-lcc!ames!pasteur!ucbvax!ORVILLE.NAS.NASA.GOV!dat
From: dat@ORVILLE.NAS.NASA.GOV ("David A. Tristram")
Newsgroups: comp.sys.sgi
Subject: zbuffer
Message-ID: <8804201847.AA15294@orville.nas.nasa.gov>
Date: 20 Apr 88 18:47:26 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 9


There doesn;t seem to be much in the way of documentation for z-buffer
access for 3000 or 4d/60's, however, if its any consolation, the GT
has *extensive* access to the z-buffer, including read/write and 
control of the comparison mode (ALWAYS,<,==,>,<=,>=,!=,NEVER), primitive
writemasks (on or off, basically), and when drawing, z-type comparisons
may also be made from the regular image planes.  How's that for the old
'its fixed in the next version' frustrations?

tristram