D3D9 Render to Texture with Multisampling

Question

I want to render to a texture using multisampling, then render that to the back buffer using a textured quad (passing it through a pixel shader.) Everything works fine without multisampling but I just can't figure out how to set it up to use multisampling.

I tried CreateDepthStencilSurface() but I don't really know what to do with that surface, or if tat's even what I should be doing.

Please help.

PS - I'm using DX9, Win32 and C++

Answer 1

You can't, not directly anyway. Here is the regular workaround:

1. Create a multisample render target using IDirect3DDevice9::CreateRenderTarget
2. Create a simple texture
3. Render to your multisample render target
4. Use IDirect3DDevice9::StretchRect to blit your multisampled content into one of the surfaces of your texture
5. Now proceed to use that texture as planned.