Best practice for simple DirectX overlay rendering

Question

I'm creating a DirectX 11 game that renders complex meshes in 3D space. I'm using vertex/index buffers/shaders and this all works fine. However I now want to perform some basic 'overlay' rendering - more specifically, I want to render wireframe boxes in 3D space to show the bounds of a particular area. There would only ever be one or two boxes in view at any one time, and their vertices would change position each frame.

I've therefore been searching for simpler DX11 rendering methods but most articles I find still prepare a vertex/index buffer for very simple rendering. I know that hardware is well optimised for processing vertex streams, but is the overhead of building and filling a vertex buffer every frame just to process 8 vertices really the most efficient method?

My question is therefore, what is the most efficient method for performing this very simple rendering in DX11? Is there any more primitive method ("DrawLine", "DrawLineList(D3DXVECTOR3[])", ...) that would be a better solution? It could be less efficient per-vertex than the standard method of passing vertex buffers because it's only ever going to be used for a handful of vertices per frame.

Thanks in advance

Rob

Answer 1

You should create a single vertex / index buffer for each primitive Shape (box, sphere, ...) and use transformation matrix to place it correctly in the world.