This a screenshot of an OpenGL program I wrote in my spare time during my undergraduate course to draw scenes with special-relativistic effects.
In this scene the spheres are orbiting clockwise around the centre sphere which is stationary (relative to the camera). The scene is illuminated with two black-body lights from behind the camera, and one green light from the top to show off the Doppler effect (red and blue shift).
If you are interested I have put the program on GitHub.
Thanks for sharing that, that's cool as hell.