Path tracing in the browser

Features

• WebGPU first, WebGL 2 as fallback

  Unidirectional path tracing with next-event estimation and MIS over rect, sphere, IES spot, directional and HDR environment lights. Without WebGPU it falls back to WebGL 2.

• OpenPBR 1.1 surface

  F82 metals, anisotropic GGX specular and coat, fuzz, thin-film interference, dispersive transmission with volume scattering, subsurface scattering and ray-marched displacement.

• Interactive with millions of triangles

  Two-level BVH with binned-SAH BLASes built in parallel Workers; moving instances only refits the TLAS. The 4.6 M-triangle Bugatti: 0.5 s build, 5.3 full-HD spp/s on an M4 Max.

• Low-noise sampling and denoising

  Owen-scrambled Sobol or blue-noise ZSobol sequences. Albedo- and normal-guided denoising with Intel OIDN (WebGPU) or joint non-local means, progressively or on convergence.

• Incremental Three.js sync

  THREESync converts standard and physical materials, lights, instancing, skinning and morph targets, and picks up transform, material and light edits on every update, without reconverting the scene.

• Offline-quality output

  Deterministic converge() with variance-driven adaptive sampling (WebGPU), AgX and ACES tone mapping, bloom, thin-lens depth of field and shadow catchers.