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- From: boylan@pi.eai.iastate.edu (Terran Boylan)
- Subject: BUMPMAP/PHONG TRIX on VGX? (REPOST)
- Message-ID: <1992Sep14.194930.25721@news.iastate.edu>
- Sender: news@news.iastate.edu (USENET News System)
- Organization: Engineering Animation, Inc.
- Date: Mon, 14 Sep 1992 19:49:30 GMT
- Lines: 46
-
- (I tried this a couple of weeks ago but got no responses....)
-
- (NOTE: forgive the repetitive use of the word "clever" in
- the following post.)
-
- Hello, everybody!
-
- I really hope this doesn't start a big "when are we gonna
- have Phong shading in hardware" thread. That's not what I'm
- after. :^) (Anybody besides me remember that guy at the SGI
- user's group meeting back at SIGGRAPH '87 or '88 that stood up
- and demanded Phong shading?)
-
- The best analog for what I'm after is a technique similar in
- cleverness to the Stencil Shadow's algorithm that was published
- a couple of _Iris Universes_ ago.
-
- What I want to know is if anybody's figured out some clever
- way of simulating bump maps on a VGX? I would assume that
- the process would involve rendering your object unshaded using a
- texture map to represent a change in normal direction. Somehow
- you'd get approximate polygon slope information from either taking the
- derivative of the Z-buffer or using a second pass where you render
- your object using color to represent normal information. The last
- step would be a pixel-by-pixel computation of some sort, possibly
- using the stencil bitplanes in some clever way.
-
- Remember, I'm not looking for displacement maps or true bump maps.
- I'm looking for SYNTHETIC bump maps, where the majority of the
- work is done in hardware. I'm not looking for a real-time interactive
- technique, and I don't care if it looks ugly on the screen while it's
- doing it. I want it for a frame-at-a-time animation technique. Images
- would be video resolution.
-
- Has anybody done this? Does what I'm suggesting make sense? Should
- I just give up the idea of having bump-mapped objects in my animations?
- Say it ain't so!
-
- Thanks a million flat shaded polygons per second!
-
- Terran J Boylan
- Sr Artist/Programmer
- Engineering Animation, Inc.
- Ames, IA 50201
-
- P.S. So when are we gonna have hardware support for FFD's?
-