James Cameron is the most famous champion for providing a way to shoot mocap actors with a virtual camera. Below you can see Kevin Margo working with the latest version of this sort of technology (V-Ray, NVIDIA, BOXX and more) to shoot his film Construct. The actors are replaced in realtime with their respective realtime robotic selves. Perhaps the fidelity could be better, but it is still very cool.
Maybe check the teaser video as well – this really shows how spectacular the mocap was – translating some lovely performances into very anthropomorphic bots. Engadget reported the rig sported 3 NVIDIA K6000 GPUs to get this level of processing done live.