I tried to implement motion blur on my card (gfII / mx) using the accumulation buffer like this: ///////////////// drawScene(); glAccum(GL_LOAD,0.5f); for (int i=1;i<=10;i++) { drawFrame(i); glAccum(GL_ACCUM, 0.5f); } glAccum(GL_RETURN,1.0f); ///////////////// while this approach does work, i can walk to the corner grocery store and back between frames. (well not really, it''s more like 1fps. the scene is just a single polygon) i have other demos that use the accum buffer (no source) and they run MUCH faster than this. does anyone have an idea why it''s so slow or what i may be doing wrong? btw, i''m not certain that there''s anything i need to do to use the accum buffer first (like when i create the window do i need to specify that i want the accum buffer? perhaps it''s doing this in software mode instead? i really dunno) thanks, ~byt

Only Professional OpenGL accel graphics cards acually accel the acum buffer, the GF2 isn''t one of them.

The accumulation buffer *IS* slow! The demos you have seen that use the accumulation buffer may be ''faster,'' but look at the size of the entire rendering window. ''Blitting'' a 300x300 window to the accumulation buffer a few times isn''t going to KILL your speed, but a 640x480 window ''blitted'' to the accumulation buffer a few times is pure suicide!

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Trent (ShiningKnight)
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ShiningKnight Games