Navigation with navcat

navcat builds a navmesh (the interconnected walkable polygons of your level) from raw geometry and answers pathfinding queries over it. Reach for it when something needs to move intelligently through the world — enemies routing around obstacles, NPCs patrolling, units ordered to a point, agents that must avoid walls and gaps. It is rendering-agnostic; navcat/three adapts it to Three.js.

Do you even need a navmesh? For "walk straight at the target on open, flat ground," a navmesh is overkill — steer directly. A navmesh earns its place once agents must route around obstacles, across uneven or multi-level terrain, or as a coordinated crowd. If your case is simpler, implementing your own steering is the right call.

Versions move — read the installed types

This skill routes you to the right capability and decision; it does not pin exact signatures, because navcat's API (export names, option fields, return shapes) shifts between versions. Before calling into it, read the installed package's exports/types (navcat, navcat/blocks, navcat/three) to confirm current names and fields. Treat the code below as shape, not contract.

The pipeline at a glance

1. Extract geometry — turn your walkable Three.js meshes (floor, terrain, obstacles) into positions/indices with getPositionsAndIndices(meshes) from navcat/three.
2. Generate the navmesh — one call: generateSoloNavMesh(input, options) from navcat/blocks for a single area (the default), or generateTiledNavMesh for large worlds and partial rebuilds.
3. Query — paths, nearest walkable point, random points, line-of-sight, over the generated navmesh.
4. Move agents — follow the path yourself each frame, or hand many agents to the crowd block.