We implemented Procedural Clouds and a Volumetric Path Tracer capable of rendering them. We use unbiased methods to render Participating Media.
Since clouds are an heterogeneous medium, we simulate interactions by delta tracking and estimate transmittance by ratio tracking. Our volumetric path tracer uses Multiple Importance Sampling (MIS) to reduce variance.
In a nutshell, our procedural clouds use volumetric SDFs modulated by Perlin noise with several octaves (fractal noise).
God rays are volumetric shadows produced by the difference in density of the cloud and a thin medium (air with some scattering) to visualize them.
Note: Everything is implemented under the Nori engine.
Big cloud blocking the sun, producing god rays.
Render with noise
Render with noise + enhanced
Denoised enhanced
To be added
Printed
