Another experiment: no spheres this time, but a real-time animated triangle mesh (the hand is from the Utah 3D Animation Repository, a textured mesh containing 15,855 triangles). The goal was to create a simple animated scene and achieve a look as close to photorealism as possible with completely dynamic, physically accurate global illumination in real-time using path tracing.
The following animation was rendered in real-time on a GTS 450 (stretching the compute capabilities of my GPU to the max):
Details will follow.
The image below was rendered with path tracing at 26 samples per pixel in 0.8 seconds on a GeForce GTS 450 (192 cuda cores at factory clocks, it would render 3 to 4 times faster on a GTX 580, which has 512 cuda cores and is clocked higher):