3D PortraitSphere is an interactive audio/video installation about the changing relationships between viewer and artwork in contemporary digital art. In traditional museum and gallery settings, visitors are observers physically separated from the works of art. If you're standing in front of the flatscreen and webcam you should see your image sticking out of the side of the 3D sphere. Optical flow motion tracking techniques and OpenGL nurbing allow participants to use their physical gestures and voices to manipulate the portrait as if it is a virtual sculpture.