
Caustify
Real-time spectral path tracer in one WebGL2 shader
Just added Caustify to Products DB: a real-time spectral path tracer that runs in one WebGL2 fragment shader. What I care about here is that the dispersion is real: each traced path samples a random wavelength and gets its own index of refraction from Cauchy's equation. It converges over frames like any progressive renderer, but what's accumulating is spectral noise rather than RGB noise.
Honest limits: four analytic scenes, no mesh import, Schlick's Fresnel approximation rather than the full dielectric equations, and I say so on the page.
Free, MIT, source included: https://j4zz.eu/caustify/
Repo: https://github.com/immineal/caustify
I'd like feedback on the spectral-to-RGB conversion in particular, happy to talk shaders or spectral rendering in the comments. Building a Kleingewerbe in Germany around physics, graphics and German-language work, this is one piece of it.
About
Wanted real wavelength-dependent dispersion running live in a browser. Shipped, then judged the demo not good enough to stay live -- taken offline 2026-08-31 for a rework. Code: github.com/immineal/caustify

Comment