In a 3D environment context, Recast.js is meant to be used with a file describing a scene geometry. Using the recastnavigation C++ library compiled to WebAssembly, it will deduce a navigation mesh: a set of polygons on which your characters can move.

Once this navigation mesh is computed, it is possible to use built-in pathfinding operations like "find the shortest path between point A and point B", taking into account obstacles, slopes, and off-mesh connections.

If you decide to use it to animate your scene characters aka "agents", it also provides a complete crowd system capable of managing all your agents movements using per-agent settings (speed, radius, ...).

play the pathfinding demo

• load any mesh in .obj format
• compute its navigation mesh with configurable parameters (cell size, agent height, slope angle, ...)
• build a solo navmesh or a tiled navmesh (better for large scenes and dynamic obstacles)
• save and load the computed navmesh to skip recomputation

• find the shortest path between two points
• find the nearest navigable point or polygon to any world position
• get a random point guaranteed to be on the navmesh

• place and remove temporary obstacles
• define off-mesh connections (jump links, doors, portals)
• assign polygon flags and group them into zones to influence pathfinding
• with instant effect, no rebuild needed

• add agents to the navmesh and drive them with a full crowd simulation
• update agents individually (speed, radius, separation weight, ...)

Browser demos are available in tests/browser/:

• webgl — WebGL rendering, crowd, obstacles and offmeshs links
• doors — off-mesh connections for door traversal
• worker — running recast inside a Web Worker (work in progress)