Incremental Potential Contact (Li et al., SIGGRAPH 2020) simulates deformable bodies with contact that is guaranteed intersection-free: contact is modeled as a smooth log-barrier energy that grows to infinity as surfaces approach, and every implicit time step is solved as one Newton optimization with continuous-collision-detection-filtered line search. No penetration, ever — regardless of time step, stiffness, or impact speed.
That robustness is expensive: each frame is a full nonlinear optimization, far too slow for real-time in a browser. The animations here were precomputed offline with libuipc, a modern GPU (CUDA) unified IPC framework, on an RTX 2070 — then quantized and streamed to this page for playback. The scenes highlight what makes IPC special: soft bodies squeezing without a single tunneling artifact, codimensional 1D rods draping with robust curve-curve contact, and a volumetric jelly body coupled with a thin cloth shell.
Generation scripts live in this site's repo under ipc_demo/gen. See also the original IPC project page and reference code.
Huge thanks to the authors of libuipc for open-sourcing such a powerful and well-engineered unified IPC framework — this page would not exist without it.