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Cyril
05-05-2008, 09:02 AM
Any body got early depth test working with a float texture (GL_DEPTH_COMPONENT_32F_NV) attached to an FBO on G80/G92 ?

I have tried it in my application and I can't get it to work, whereas it works well with GL_DEPTH24_STENCIL8_EXT.
I use 169.21 on a G92 under windows XP.

Thank you

-NiCo-
05-05-2008, 09:14 AM
Here's what the guidelines say:

- Clearing z is close to free and enables early z-cull optimizations

- Donít create triangles with holes in them (that is, avoid alpha test or texkill)

- Donít modify depth (that is, allow the GPU to use the interpolated depth
value)

But since it works for GL_DEPTH24_STENCIL8_EXT I don't think it's an issue.

Perhaps it's because the Z-buffer uses a lossless compression for GL_DEPTH24_STENCIL8_EXT to save bandwidth which has a good mapping for the early-Z while the 32F format is not compressed.