I've tracked a sequence in my bathroom, and I want to reflex an object in the mirror. I've put a plane where the mirror is, and the track works pretty good. The problem comes with the material I'm using in the plane: I've just activated the color channel (for the image sequence) and the reflexion channel. And, as you can see, it doesn't reflex pretty good:
you are reflecting onto a plane which contains your image, yes? It won't work that way since the image is "in the mirror" so to speak - it's like looking at a reflection in a polished wooden table, the reflection is never perfect like in a mirror because the wood texture in in there so you only get a weak reflection. For it to work the way you expect the bathroom needs to be set up like in reality. The bathroom needs to be behind the camera (well partly in front too) which will be behind the character as well so the mirror has only reflection (color should be gone or white or black) and it reflects like in reality.
Were you ever able to figure this out? I am doing something similar, and running into the same problem. The only guy who responded to this didn't seem to really understand the problem. The reflection has a transparency that doesn't seem to be possible to get rid of. I hope someone has a solution.