On the GPU, WoSX reduces warp divergence in its Monte Carlo random-walk solvers using dynamic load balancing through a persistent-threads implementation.
PDEs and boundary conditions are written in Slang (shader-slang.org), natively supporting CUDA, Vulkan, and Direct3D.
Rendering nerds! Check out our latest work "Vector-Valued Monte Carlo Integration Using Ratio Control Variates" that has just gotten the best paper award at SIGGRAPH 2025. This paper presents a method that reduces variance of a wide range of rendering and diff. rendering tasks with negligible cost.
Interactive Electrostatics: Electric potential and field magnitude computed on-the-fly for a moving micro-electronic comb drive.
Bypassing the volume-meshing step entirely allows for real-time feedback during geometric articulation.
Releasing Walk on Spheres Extensions (WoSX): a GPU-accelerated C++/Python library for Monte Carlo physics simulation on complex geometry.
Think path tracing but for physics beyond light transport: heat, electrostatics, potential flow, deformation & more!
github.com/nv-tlabs/wosx
WoSX aims to be for MC physics what PBRT (pbrt.org) is for rendering: clear, inspectable, extensible software researchers & engineers can build on.
It currently targets steady-state problems, not general multiphysics—but more features are under active development!
Exterior Potential Flow: idealized flow around arbitrary geometry, inspected locally on a slice plane.
This is a setting where generating a volume mesh is not just inconvenient—the exterior domain has infinite extent.
“Rendering” Physics.
WoSX uses Walk on Spheres-style random walks to solve Laplace, Poisson, and screened Poisson problems with Dirichlet, Neumann, and Robin boundary conditions.
Estimate physical fields only where needed, using boundary queries via BVHs or SDFs.
WoSX includes several engineering-inspired demo applications, with more on the way.
View-dependent Thermal Analysis: Steady-state heat conduction on a Mars Rover. WoSX effortlessly handles the raw, unoptimized asset (millions of triangles), evaluating the field only where needed.
The Meshing Bottleneck.
Traditional FEM/CAE pipelines often spend major time on volumetric meshing & geometry repair: fragile, memory-heavy, hard to parallelize.
WoSX aims to make physics simulation more like rendering: embarrassingly parallel, localized & free of volume meshes.
Spread the word, the #SIGGRAPH Thesis Fast Forward 2025 is out now! Check out incredible PhD research from physics simulation to programming languages and human centered AI-based digital painting youtu.be/8esFWCQ_46Y
Rohan Sawhney
Empowering real-time graphics developers with advanced language features and machine learning capabilities.
