I'm working on a shot where a CG Optimus Prime drives up. One thing that would really enhance the realism of the shot would be to add Optimus's reflection to the windows in the building on the live action plate.
Is it possible to do this? I would need to composite the reflection of just Optimus but still allow the background plate to show...like an alpha channel reflection. Creating small planes of glass material in 3d space in the approximate location obviously doesn't work because there's nothing behind the glass in the virtual 3d space.
I did some searches of the web but couldn't find any solutions relevant to this problem.
I'm using Blender with Octane Render.