Euclidean fog

One emitter and three balls: red diffuse, green mirror, and blue glass, surrounded by scattering fog.

cargo run --release -p hypertrace-examples --bin fog

Browser viewer

$A white emitter lights fog around red diffuse, green reflective and blue refractive spheres against darkness.$

Optional. Requires WebGPU; starts only when requested.

Native requirements and instructions

Technical details

Drag to look; Tab locks the mouse. WASD moves; Space/C moves up/down; Q/E rolls. Scroll zooms; R resets. The viewer pauses when hidden or outside the page’s visible area. Open viewer separately.

What to observe

Let the image accumulate. Compare the red sphere’s shadow with reflected green light and light bent through the blue sphere into the fog.

The fog does not emit light. Its glow is light from the source scattered toward the camera.
Both surface and volume interactions consume the path budget. More samples reduce noise; a larger path budget also includes longer light paths.
There is no floor or ambient illumination. With all emission switched off, the image is black.
The current homogeneous medium fills the entire scene, including glass. Object-specific medium boundaries and anisotropic scattering are not implemented.

Geometry of the three spaces · Scene construction

Screenshots

Click an image to open its full-resolution PNG.

A white emitter lights fog around red diffuse, green reflective and blue refractive spheres against darkness. — Initial view. 2560 × 1920 · 8192 samples per pixel · 12 path events.
Settings · Render source

A closer view of the light, blue glass, and surrounding fog. 1600 × 1200 · 8192 samples per pixel · 12 path events.
Camera and settings · Render source

Earlier capture

Earlier approved fog capture with the light and three colored spheres. — Earlier scene revision, preserved as originally published: 640 × 480, 32,768 samples. Original settings and source revision.