Forum - C4Dzone

Is it possible to do what I have depicted in the image attached in After effects? Its seems like a simple thing but I have tried and cannot seem to figure out how this is done. I understand how to use the compositing tag to extract a solid but how do I use a shape layer and how do I place the shape layer between my two cubes? If this is possible can someone please explain to me in steps how to go about this.