If you're bored and you want to see if your card has it
Edited by - Jonathan on 3/16/00 6:15:31 PM
OpenGL Accumulation buffers...
Author
Lemme guess. This hasn't been implemented in any consumer hardware yet, has it? Is the revolutionary T-Buffer that 3dfx is talking about, or is that something neater?
I ask this because I just spent a half hour or so getting some neat motion blurring code going, fired up my program, hit 'M' to start blurring, and everything suddenly slows to a crawl and software rendering takes over. ::sigh:: No more quick quick Voodoo3.
Jonathan
If you're bored and you want to see if your card has it
Edited by - Jonathan on 3/16/00 6:15:31 PM
If you're bored and you want to see if your card has it
Edited by - Jonathan on 3/16/00 6:15:31 PM
It runs fast on my TNT2, but there''s no motion blur at all.
I''m not sure if any recent chips support accumulation buffers in hardware. My guess is they don''t, but I could be wrong.
The T-Buffer is a simpler implementation of accumulation. Because of that, it''s easier to use, but also more restrictive.
Here''s 3dfx''s white paper on the T-Buffer. Towards the end they actually give you some useful information about how it works:
http://www.3dfx.com/3dfxTechnology/tbuffer/tbuffer_whitepaper.pdf
Scott Franke [druid-]
sfranke@usc.edu
druid-'s GL Journal
http://www.gamedev.net/opengl
I''m not sure if any recent chips support accumulation buffers in hardware. My guess is they don''t, but I could be wrong.
The T-Buffer is a simpler implementation of accumulation. Because of that, it''s easier to use, but also more restrictive.
Here''s 3dfx''s white paper on the T-Buffer. Towards the end they actually give you some useful information about how it works:
http://www.3dfx.com/3dfxTechnology/tbuffer/tbuffer_whitepaper.pdf
Scott Franke [druid-]
sfranke@usc.edu
druid-'s GL Journal
http://www.gamedev.net/opengl
I''ve tried it also,
on a PIII 600, w/ 256mb RAM and a GeForce DDR,
it still crawls (<1fps) with motion blurring.
-Mezz
on a PIII 600, w/ 256mb RAM and a GeForce DDR,
it still crawls (<1fps) with motion blurring.
-Mezz
Author
::sigh:: I was afraid of that. Oh well, I guess I can fudge it using lots of alpha blending and fun stuff like that.
Jonathan
Jonathan
There is a reasonably fast way to emulate motion blurring.
You should render your primitives at a lower intensity, say N times lower, where N would be the number of motion blur passes. Then, you render the scene the same as you did in the accumulation buffer sample, N times, with additive blending enabled (no need for alpha here). This yields a motion blur effect, but with reduced color precision. You might want to use GL_LEQUAL Z testing and eventually the GL_POLYGON_OFFSET extension to solve Z-buffer problems.
DaBit.
You should render your primitives at a lower intensity, say N times lower, where N would be the number of motion blur passes. Then, you render the scene the same as you did in the accumulation buffer sample, N times, with additive blending enabled (no need for alpha here). This yields a motion blur effect, but with reduced color precision. You might want to use GL_LEQUAL Z testing and eventually the GL_POLYGON_OFFSET extension to solve Z-buffer problems.
DaBit.
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