I have a project that I'm doing in Managed DirectX (DX9) where I want to render lots of grass. My current method (many draw calls) is slow, but I've heard Geometry Instancing can fix that.
I know that I have to have one vertex buffer to store the vertices that will drawn multiple times. I know that I need another vertex buffer to store the transformations (from what I've seen you can only have one additional vertex buffer). So should the second vertex buffer store transformation matrices? I tried coding this, but when I want to create a new vertex buffer one of the required parameters is vertexFormat, but I can't supply a vertex format since this is a matrix.
I also wanted to try to have the second vertex buffer store the translation values as Vector3, but how do I tell DirectX that the values in the second vertex buffer are to be used as translation values? Secondly, I also need rotation values. Do I store these in a third vertex buffer?
Basically, I want to use geometry instancing to draw multiple instances of a quad that are rotated and translated.
