Snow Chunks & Powder: "Horton" (2008)


Copyright Blue Sky Studios.

This effect is a modification of the ballistic trajectory-based fluid splash rig created for "Ice Age: The Meltdown".

I designed and supervised the modeling of five separate snow chunks, each with a precise scale of <<1, 1, 1>>. They were then instanced randomly to individual ballistic trajectory events.  Each chunk instance was scaled disproportionately and randomly.  As with the fluid splash rig, the start frame, scale, speed, rotation & direction are controlled by slideable values in Maya's Channel Editor; no keyframes. The powder is simple surface emission from the models themselves, with a bit of turbulence added.

I worked with Hugo Ayala in R&D to develop a method for stopping the chunks at the surface. When a chunk intersects the surface, it stays in place but continues rotating for 2 additional frames. That was sufficient to eliminate any unnatural stiffness at collision time.

I executed several shots myself. Otherwise I supervised and supported the effect throughout the entire sequence. This clip starts with a demo of the models and 3 short initial tests, followed by final frames & test renders.

Below is a photo I took in my driveway. The snow chunk models were loosely based on these: