Spherical space

An off-center sun, diffuse and refractive balls, and a glowing landmark on a spherical floor.

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

Browser viewer

A blue glass ball beside an orange diffuse ball, a bright off-center sun, and a green glowing sphere above a pentagon-tiled floor.

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

Look for the blue ball’s caustic and the orange ball’s contact shadow. Move around the floor to see how illumination changes toward the opposite pole.

The “plane” is a great 2-sphere inside 3-dimensional spherical space. Its tiling closes after twelve pentagonal faces.
The orange and clear balls rest at opposite floor poles. Turn around to find the clear ball.
A free ray returns to its starting point and direction after a distance of 2πR. The travelled distance still matters for event ordering and fog.
The blue glass ball is on the sun-facing side of the orange one. Look for its caustic on the floor. The floor is mostly Lambertian, with small reflective and transparent components.

Geometry of the three spaces · Scene construction

Screenshots

Click an image to open its full-resolution PNG.

A closer view of the glass ball, caustic, and contact shadow. 1600 × 1200 · 4096 samples per pixel · 6 path events.
Camera and settings · Render source