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Goofus43
10-13-2017, 11:53 AM
Is there a source anywhere which tells how many recently calculated vertices are kept in storage in a range of GPUs? I know there are some as I have demonstrated their effect, and have devised a scheme to sort of estimate how many are in my system by doing various intermediate transforms on indexed arrays. Still, I would like to know for a range of typical GPUs rather than just the one in my computer so I could depend on it.

Am working on an animation scheme where meshing could be greatly improved and simplified if I could count on number being in 15-30 range.
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Back to this idea and edit:

Results are very inconsistent. Seems too dependent on exact prior calculations. I've discarded my idea and going the hard way around.

mhagain
10-13-2017, 01:43 PM
Discussed here: https://www.khronos.org/opengl/wiki/Post_Transform_Cache

Summary: You can expect 20+ but it is hardware-dependent.

GClements
10-13-2017, 03:26 PM
And also dependent upon the number of variables output from the vertex shader (the vertex cache is sized in bytes, not vertices). There's no mechanism to query the cache size directly, although it shouldn't be hard to determine it via profiling.

If the vertex shader is particularly expensive, you can reduce the cost of cache misses by pre-processing the vertices using transform-feedback mode or a compute shader, then using a pass-through vertex shader during rendering.