vertex cache question

There are several answers to your question.

The first part is that for performance reasons you want to minimize render state changes when rendering geometry, meaning that you want to batch render calls based on certain attributes (i.e. batch based on material), if you look up the ATI or NVIDIA sites you will find presentations on how to group your render calls to improve performance.

The second part is about the vertex cache on the video card. You can rearrange your vertices to better utilize the video card vertex case, this rearrangement depends on the video card you are running on, and DX provides some easy to use functions to do this.

Note that these are two different systems, the first is basically a system that sorts/groups your render calls to minimize state changes.

The second is a system that rearranges your vertex buffers/index buffer pairs depending on the graphics card you are running on.

Hope this helps

Great, yeah i thought that was what it should do, i'm currently working on mine to group vertices together based on texture or material as this should allow for a minimal number of state changes, at least i hope so. .