Culls a 3D grid of spheres against a test camera's view frustum (6-plane extraction + sphere/plane distance test) and only draws the spheres that are inside or intersecting. The test camera's frustum is drawn as a yellow wireframe box, and its eye position is marked with a small cube when viewing from the observer camera (top-down), so the culling effect is visible from outside the test camera itself. The title bar shows drawn/total sphere counts.
1: view from test camera.2: view from observer camera.e/l/b//: select what Left/Right/Up/Down/i/omove on the test camera (eye / look / both / slide).Left/Right/Up/Down: move the test camera on its local x/y axes.i/o: move the test camera in/out along its local z axis.r/p/y: roll / pitch / yaw the test camera.+/-: widen / narrow the test camera's field of view.w/s: wireframe / solid fill.- Left-drag : orbit, Right-drag : pan, Wheel : zoom,
space: reset.
- G. Gribb & K. Hartmann, "Fast Extraction of Viewing Frustum Planes from the World-View-Projection Matrix", 2001 — PDF — the 6-plane extraction method used here.
- Lighthouse3D — View Frustum Culling — geometric vs radar approaches, and the sphere/plane test.
- The ryg blog — Frustum planes from the projection matrix — why the row-combination trick works.