I worked as a technical director in the sets department and lightspeed (render optimization) department on Cars 3. I worked on several pipeline and render optimization tools, but the bulk of my work was related to vegetation. I worked closely with my lead, Matt Kuruc, to develop a procedural vegetation animation pipeline for render-time keep alive animation. This system, which we named, “Gentle Breeze,” could procedurally animate entire forests of trees at render time by leveraging instancing and pre-baked topologically sorted branch orderings. Performance was critical for this system since the show had tons of vegetation that all needed to be animated.
I also worked on a Houdini based tool for procedurally generating curve hierarchies with which we used to simulate the trees. Matt and I published an article for SIGGRAPH 2017 and spoke at the conference. In addition we spoke at the Disney internal conference, “DISGRAPH”.
The tool I created was used to rig most of the vegetation on the show, and was designed to handle nearly any input model. To my knowledge it is still being used.
I also had the fortune of creating procedurally generated hay bales using Houdini. These hay bales were made entirely of curves so they could be simulated. These models were used again in Toy Story 4.