I’m currently a software engineer in CLO Virtual Fashion, working on the cloth simulation for CLO, Marvelous Designer, and Jinny!
My current interests are:
- Cloth, Soft Body, and Rigid Body Simulation
- FEM-based simulation (Baraff-Witkin, Projective Dynamics, ADMM, IPC)
- CPU Optimization (SIMD, data-oriented design)
During grad school I have implemented an articulated body simulator from scratch (initially for a class project, but continued working on it for more than a year).
List of things that I’ve created:
Simulation of articulated rigid bodies without any loops (a tree structure). This is done using the Featherstone forward dynamics algorithm, which guarantees O(N) simulation time when there are N links.
Contacts and friction between articulation and static object
- I used Projected Gauss-Seidel (PGS) for the contact resolution algorithm. Initially I tried implementing the bisection method from Hwangbo et al. (2018), but found it too hard to tweak.
Contact between multiple rigid body objects
- I implemented the Proximal Operator Method explained well in the SIGGRAPH course on contact simulation: (https://siggraphcontact.github.io/).
FEM Soft Body Simulation
- I implemented both Projective Dynamics (Bouaziz, 2014) and ADMM-PD (Narain, 2016). Tests are done for the octupus mesh used in SoftCon (Min, 2019). Some of this code ended up being used for the Musculoskeleton from X-Ray project.
Rigid Body & Soft Body coupled simulation
- Related with the Musculoskeleton from X-Ray project, my initial line of research were to simulate the dynamics of soft-body volumetric muscles attached to reduced articulated bodies. This turned out to be much harder than I’ve thought; the simulation that I’ve created (by modifiying the original ADMM-PD formulation) had issues with stability and momentum preservations and therefore was abandoned (in favor of soft positional constraints).
Demo reel for the original class project in 2020:
References I have used for creating the simulation:
Junggon Kim, Lie Group Formulation of Articulated Rigid Body Dynamics. PDF link
Kevin M. Lynch and Frank C. Park, Modern Robotics: Mechanics, Planning, and Control.
Roy Featherstone, Rigid Body Dynamics Algorithms.
J. Hwangbo, J. Lee and M. Hutter, “Per-Contact Iteration Method for Solving Contact Dynamics,” in IEEE Robotics and Automation Letters, vol. 3, no. 2, pp. 895-902, April 2018.
Sheldon Andrews and Kenny Erleben, “Contact and Friction Simulation for Computer Graphics.”
Bouaziz, Sofien and Martin, Sebastian and Liu, Tiantian and Kavan, Ladislav and Pauly, Mark, 2014. “Projective Dynamics: Fusing Constraint Projections for Fast Simulation.” ACM Trans. Graph. 33, 4, 154. (SIGGRAPH 2014)
Rahul Narain, Matthew Overby, and George E. Brown. “ADMM ⊇ Projective Dynamics: Fast Simulation of General Constitutive Models”. In Proc. ACM SIGGRAPH / Eurographics Symposium on Computer Animation (SCA), 2016.
Sehee Min, Jungdam Won, Seunghwan Lee, Jungnam Park, and Jehee Lee. 2019. “SoftCon: Simulation and Control of Soft-Bodied Animals with Biomimetic Actuators.” ACM Trans. Graph. 38, 6, 208. (SIGGRAPH Asia 2019)