Perception

Frustum

A frustum is the truncated-pyramid volume of 3D space visible to a camera, bounded laterally by the projection of the image boundaries and in depth by near and far planes. In robot perception, frustums link 2D image evidence to 3D space: a 2D detection defines a frustum in which the object must lie, an idea exploited by Frustum PointNets for 3D detection, and frustum culling restricts processing to visible space.

Why it matters for physical AI

Lifting 2D detections into 3D is a recurring need when robots act on camera-based perception; frustum reasoning provides the geometric bridge between image-space models and the metric world where grasps and motions are executed.