quick question: backface culling

What is does is not render the triangles that are wound in the order you set.

D3DCULL_CCW for example does not render any triangles that are ordered counter-clockwise.

I know what it does, but I don''t know WHERE it happens.
For example, it happens at render time AFTER all depth/stencil tests?
Or, the exact place is hardware-dependent?

I believe it happens before all tests and alpha blending.

Maybe this pic can explain clearly:

www.sky-info.com/uoboy/pl.bmp

We create world.

The pipeline transorms the vertices and does not draw any that are back facing, thus alpha/stencil ops are not an issue.
Neil

WHATCHA GONNA DO WHEN THE LARGEST ARMS IN THE WORLD RUN WILD ON YOU?!?!

That means when I call ProcessVertices on a vertex buffer, the resultant transformed VB won''t contain triangles that are back-faced?

With ProcessVertices() backface culling WILL NOT remove any triangles. So the output buffer will have the same number of entries as the input buffer. ProcessVertices() also ONLY ever happens in software (due to the read dependency - graphics hardware is intended to be one way: write only) so stencil buffers etc will have no bearing.

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Simon O''Connor
Creative Asylum Ltd
www.creative-asylum.com