CitrusJelly.

The jelly. A tetrahedral, mass-weighted XPBD body. Co-rotational tetrahedral shape matching, volume constraints, strain limits, friction and velocity damping make it wobble. The rind is firmer than the flesh.

The knife. Draw across the slice. A vertical plane divides its rest-space triangles; new particles inherit the moving surface’s position and velocity.

The cutters. Four rounded polygon walls divide triangles into inside and outside regions. Connected regions become separate bodies, including the surrounding piece with its open hole. Lift the centre with the hand.

The light. WebGPU renders a back-face depth pass, an HDR studio and a refractive surface with absorption, procedural citrus tissue, softbox reflections and four-sample antialiasing.

Controls. Space pause · N nudge · R reset · H hand · K knife · C cutter · 1–4 shapes. Empty-space drag orbits; wheel zooms, or twists a held patch. Double-click restores the view.

This compact study uses triangle-region clipping rather than a centimetre distance grid with Euclidean morphology. Bevels, embedded tissue, thickness and shadows are visual approximations. It is not a calibrated food or engineering simulation.