Robert Grzeszczuk (rg++at++hoek.engr.sgi.com)
Tue, 13 Apr 1999 17:41:23 -0700 (PDT)
If you are referring to Impact graphics, that is indeed correct. Here's an
excerpt from 'man glTexImage3DEXT:'
...
MACHINE DEPENDENCIES
...
On High Impact and Maximum Impact systems, the following restrictions
apply to 3D texturing:
1. Perspective views are not supported.
...
So, you can't enable it. One of your options, as you point out, is a finer
tesselation (e.g., horizontal blinds). If you have a lot of control over your
geometry, try drawing the polygons parallel to the projection plane. Ortho
projection is another easy way out. Somewhat more involved is deomposing the
3D texture into a stack of 2D textures. In this appraoch, if you insist on
properly tri-linearly sampling you can use blending circuits to accomplish the
inter-slice interpolation. Let me know if you want to know the details.
-rg
--- Forwarded mail from hatch++at++hell (Don Hatch)
Date: Tue, 13 Apr 1999 15:32:35 -0700
From: hatch++at++hell (Don Hatch)
To: rg++at++cthulhu
Subject: (Fwd) Perspective Correction of 3d-Textures?
--- Forwarded mail from Frank Foehl <foehl++at++rus.uni-stuttgart.de>
Date: Tue, 13 Apr 1999 14:27:33 +0200
From: Frank Foehl <foehl++at++rus.uni-stuttgart.de>
To: info-performer++at++sgi.com
Subject: Perspective Correction of 3d-Textures?
I've just noticed that there seems to be no perspective
correction when rendering polygons with 3d-textures mapped
onto them.
Do I have to put up with it (I'd use a finer triangle mesh instead
of few large triangles) or can I switch on perspective correction?
(how?)
Cheers,
Frank
-----------------------------------------------------------------------
List Archives, FAQ, FTP: http://www.sgi.com/software/performer/
Submissions: info-performer++at++sgi.com
Admin. requests: info-performer-request++at++sgi.com
---End of forwarded mail from Frank Foehl <foehl++at++rus.uni-stuttgart.de>
-- Don Hatch hatch++at++sgi.com (650) 933-5150 Silicon Graphics, Inc.
---End of forwarded mail from hatch++at++hell (Don Hatch)
This archive was generated by hypermail 2.0b2 on Tue Apr 13 1999 - 17:41:26 PDT