I'm currently have an application that has ~10k draw calls. I implemented a batching scheme where I group all objects that share material, vertex format, etc and pre-transform them by their world matrices and put all those objects in one vertex buffer / index buffer, and then draw them with
DrawIndexedPrimitive (I do this every frame, since some objects might have moved / changed material etc). However, this method is always slower than if I just had multiple draw calls. Using VTune, it seems most of my time is spent computing the transformed vertices and copying the vertex/index data into the buffers.
My question is: Is this expected? Do systems that perform batching typically cache the batched data or are there some that get away with batching every frame like I am attempting to do (and if so, are there any tips for what I might be doing poorly)?
My application is in DirectX 9, but I'm curious about solutions in other platforms as well (OpenGL or DirectX 11).