Implementing Volumetric Fog and Atmospheric Clouds in Web Graphics
Simulating heterogenous fog density fields, Beer-Lambert light extinction, and 3D noise ray marching for immersive architectural environments.
Distance-based height fog fails to capture dynamic atmospheric density. Ray marching volumetric fog shaders evaluates 3D noise textures along camera view rays, simulating realistic light absorption, scattering, and cloud shadows.
1. Beer-Lambert Absorption & In-Scattering Math
Evaluating the Beer-Lambert law inside fragment shader ray-marching loops calculates light attenuation through medium density fields, combining out-scattering absorption with directional light in-scattering.
2. Procedural 3D Noise Fields & Worley Turbulence
Sampling pre-computed 3D Perlin-Worley noise textures creates realistic heterogeneous fog formations and billowy cloud structures without storing heavy volumetric VDB grids in RAM.
3. Temporal Reprojection & Low-Resolution Ray Marching
Executing ray marching passes at quarter-resolution and upsampling results using temporal jitter reprojection reduces GPU instruction overhead significantly while maintaining smooth 60 FPS viewports.