FurryBall, a GPU accelerated renderengine for Autodesk Maya boasts real-time simulation of lighting effects and physics inside the native Maya Environment. From their website:
Have you ever dreamed of a 3D renderer implemented directly into Maya 3D that has the capacity to light, rotate, or change parameters in real-time in scenes that contain textures, bump maps, soft shadows, reflections, refractions, and dynamic hair? Your dreams have come true – introducing FurryBall!
Demonstration videos on their website do a good job showing the capabilities, and a 30-day trial (registration required) is available on their website. The full version sells for $490 – $2200, depending on the feature set.
See a commercial rendered entirely via FurryBall on a GeForce GTX285, 1 minute per frame, after the break.
FurryBall GPU realtime renderer for Maya.