OK, Imagine you have set up the geometry for a small 3d world, and now you have to render it. First, you cut off all the polys that are not visible at that moment, so that only the visible are rendered. But how do you render the visible ones using DrawIndexedPrimitive (i don''t want to use Vertex Buffers yet)? Do you call DrawIndexedPrimitive passing all the vertices of your world, but only the indices of the visible vertices? VBMaster