Sum-of-Squares Collision Detection for Curved Shapes and Paths

Paul Zhang, Zoë Marschner, Justin Solomon, Rasmus Tamstorf Sum-of-Squares Programming (SOSP) has recently been introduced to graphics as a unified way to address a large set of difficult problems involving higher order primitives. Unfortunately, a challenging aspect of this approach is the computational cost—especially for problems involving multiple geometries like collision detection. In this paper, […]

Adaptive Rigidification of Discrete Shell

Alexandre Mercier-Aubin, Paul G. Kry We present a method to improve the computation time of thin shell simulations by using adaptive rigidification to reduce the number of degrees of freedom. Our method uses a discretization independent metric for bending rates, and we derive a membrane strain rate to curvature rate equivalence that permits the use […]

A Multilevel Active-Set Preconditioner for Box-Constrained Pressure Poisson Solvers.

Tetsuya Takahashi, Christopher Batty Efficiently solving large-scale box-constrained convex quadratic programs (QPs) is an important computational challenge in physical simulation. We propose a new multilevel preconditioning scheme based on the active-set method and combine it with modified proportioning with reduced gradient projections (MPRGP) to efficiently solve such QPs arising from pressure Poisson equations with non-negative […]

A Generalized Constitutive Model for Versatile MPM Simulation and Inverse Learning with Differentiable Physics

Haozhe Su, Xuan Li, Tao Xue, Chenfanfu Jiang, Mridul Aanjaneya We present a generalized constitutive model for versatile physics simulation of inviscid fluids, Newtonian viscosity, hyperelasticity, viscoplasticity, elastoplasticity, and other physical effects that arise due to a mixture of these behaviors. The key ideas behind our formulation are the design of a generalized Kirchhoff stress […]

Micropolar Elasticity in Physically-Based Animation

Fabian Löschner, José Antonio Fernández-Fernández, Stefan Rhys Jeske, Andreas Longva, Jan Bender We explore micropolar materials for the simulation of volumetric deformable solids. In graphics, micropolar models have only been used in the form of one-dimensional Cosserat rods, where a rotating frame is attached to each material point on the one-dimensional centerline. By carrying this […]

A comparison of linear consistent correction methods for first-order SPH derivatives

Lukas Westhofen, Stefan Rhys Jeske, Jan Bender A well-known issue with the widely used Smoothed Particle Hydrodynamics (SPH) method is the neighborhood deficiency. Near the surface, the SPH interpolant fails to accurately capture the underlying fields due to a lack of neighboring particles. These errors may introduce ghost forces or other visual artifacts into the […]

DiffXPBD : Differentiable Position-Based Simulation of Compliant Constraint Dynamics

Tuur Stuyck, Hsiao-yu Chen We present DiffXPBD, a novel and efficient analytical formulation for the differentiable position-based simulation of compliant constrained dynamics (XPBD). Our proposed method allows computation of gradients of numerous parameters with respect to a goal function simultaneously leveraging a performant simulation model. The method is efficient, thus enabling differentiable simulations of high […]

Two-Way Coupling of Skinning Transformations and Position Based Dynamics

Yuhan Wu, Nobuyuki Umetani Skinning transformations allow digital characters to be animated with minimal user inputs. Physics simulations can improve the detailed dynamic movement of the animated character; however, such details are typically added in the post-processing stage after the overall animation is specified. We propose a novel interactive framework that unifies skinning transformations and […]