A short film from Alex Weil has some great VFX and CG work done using RealFlow, Houdini, Mental Ray, and several others.  They document the process (and show the great film) over at FXGuide.

For one particular shot of a hoof impacting on the ground and causing grass and plant life to start growing, artists looked to the initial design frame by Park. “It was the initial design frame of this shot that inspired the whole story for her,” recalls Weil. “It is a nod to Hayao Miyazaki’s amazing animated film Princess Mononoke, the idea of life and growth spawning and growing from the creatures and the car parts. Based on her design frame, we matched the composition and began creating various plants to grow from the ground. We modeled and rigged all of the plants as opposed to using PaintFX.”

via ShapeShifting with Charlex | fxguide.