Billiards in a polyhedron

regular tetrahedron

Table

Every-face orbits

Periodic orbits that visit every face of the solid — every face means exactly once. A knot name marks a knotted orbit. Each face sounds its own note.

tilt°

slide

Tilt rotates the launch direction; slide translates the launch point across the beam. A translation-family orbit survives sliding, never tilting.

family

Sound

volume

room

tuning

One steel-pan note per face, pitch rising with the face's height. Loudness follows the normal component of the impact, so grazing hits whisper.

Launch

azimuth

elevation

Click any face to move the launch point there. Drag to orbit the camera, scroll to zoom.

point

dir

Motion & view

speed

orbit trail

faces

The orbit-trail length applies to the periodic presets. A free launch (random, or click a face) keeps its whole path — up to 60,000 bounces — so density and equidistribution are visible; the face-hit gauge appears at bottom left.