Perception

Voxel Grid

A voxel grid is a discretization of 3D space into regular cubic cells (voxels), each storing quantities such as occupancy probability, truncated signed distance, color, or learned features. Voxel grids underpin occupancy mapping frameworks like OctoMap, TSDF-based reconstruction, collision checking for motion planning, and the voxel-downsampling filters used to regularize point clouds. Memory grows cubically with resolution, motivating sparse structures such as octrees.

Why it matters for physical AI

Explicit volumetric maps give manipulation and navigation systems queryable free-space and surface geometry, and voxelized scene features increasingly feed 3D policy architectures that reason beyond single camera views.