Frustum

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. ...

Lookat-camera keyframe animation with createCameraTrack. A bound animCam plays a four-keyframe track; a separate viewCam orbits around the abstraction — eye polyline, gaze rays, per-keyframe mini-camera markers. A live frustum follows playback, and an FBO inset shows what animCam actually sees. Toggle TEX and that inset slides onto the live frustum’s near plane — the frustum becomes a window. Two createPanel instances drive the whole thing: one binds checkboxes to UI state, one binds transport controls to the track. ...

Perspective projection is a fundamental concept in 3D graphics. The transformation maps a view frustum — a truncated pyramid — into a cube of Normalized Device Coordinates (NDC), producing the foreshortening effect that makes 3D scenes look convincing. The sketch below morphs a set of cajas (boxes) continuously from world space into NDC space, rendered from a third-person camera that also displays the frustum being transformed. Shaders The morph lives in a single GLSL hook injected into p5’s base shaders through buildColorShader and buildStrokeShader — no shader files needed. ...