While Eagle3D is designed for rendering 3D views of a board rather than creating a solid model, this is nonetheless a useful tool to explore. Be prepared to step over a few hurdles to run some of the software that might not run natively on recent OSes. Think this elaborate dance is worth it worth it? Check out this visualization linked here.
Using Eagle3D and POV-Ray, you can make realistic 3D renderings of your PCBs. Eagle3D is a script for EAGLE Layout Editor. This will generate a ray tracing file, which will be sent to POV-Ray, which in turn will eventually pop out the finalized image of your PCB.