Visibility testing
Per-object frustum culling with visibility. Sixty mixed primitives drift around in a wide volume; each frame their bounds — AABBs for boxes, spheres for spheres — are tested against a fixed test camera’s frustum, with the six frustum planes pre-computed once per frame via bounds({ mat4Eye }). Three return states drive the render: solid lit material for VISIBLE, amber wireframe for SEMIVISIBLE (the bounds straddle a plane), faint grey for INVISIBLE. Toggle the test camera’s projection between perspective and orthographic with the gold checkbox; drag to orbit the observer and watch the cyan wireframe stay put while objects drift through it. ...