opueyociutad / pb-procedural-clouds

Procedural Clouds and God Rays

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.

Cool results

Procedural clouds and God Rays

Big cloud blocking the sun, producing god rays.

Render with noise

Render with noise + enhanced

Denoised enhanced

To be added

Printed

Little Disneysh cloud

Sky