I'm trying to integrate a C++ - based dynamic sky rendering library (SilverLining) into Unity3D. Under OpenGL this seems feasible, since I can draw my skybox and volumetric clouds directly to the current context before and after each frame render. But under Direct3D, you need the IDirect3DDevice9 pointer to do any drawing, and I can't see any way to obtain the device used by Unity and pass it into the plugin.
Is there any mechanism whereby a plugin can render to Unity's Direct3D device?