David Ryu
Abstract:
Featuring plush rats, well-groomed humans, and a colony of rodents
numbering a thousand strong, Ratatouille had shots where the original
scene descriptions contained many hundreds of millions of hairs. To
make these shots renderable, we developed many new technologies to
optimize our RenderMan-based hair rendering pipeline, including
caching to speed up runtime sculpting, a technique for optimizing
bounding boxes for RiProcedurals, and a smooth level-of-detail system
incorporating depth-of- eld and motion blur. These techniques resulted
in an order of magnitude reduction in hair rendering time and memory
compared to the already optimized pipeline used previously in Pixar
films.
Paper (PDF)
Available as Pixar Technical Memo #07-09