NavMeshCreateParams

TileCache

In short TileCache is an extension of the navmesh system that allows dynamic updates of the navigation mesh in smaller regions (tiles) instead of rebuilding the whole mesh.

If you alter the TileCache, you need to wait until it is fully updated. Use this function:

WaitForFullTileCacheUpdate(navMesh: NavMesh, tileCache: TileCache)

If you are altering multiple obstacles at once, set doNotWaitForCacheUpdate = true and call WaitForFullTileCacheUpdate(navMesh: NavMesh, tileCache: TileCache) at the end of the batch operation. If it is set to false, every obstacle operation returns only after the TileCache has been fully updated.

Note: If you are not dealing with many obstacle updates, you can wait for the TileCache update in the render loop.

TileCacheMeshProcess

tileCacheMeshProcess is a callback function used in Recast’s tile cache system.

Its purpose:

During tile cache generation, each tile is processed into polygons (the navmesh).
tileCacheMeshProcess allows you to customize each polygon’s properties, such as:
- polyAreas → the type of area (e.g., walkable, road, stairs).
- polyFlags → flags used by agents/queries for filtering or cost calculations.

Think of it as a hook for assigning areas and flags per polygon, giving you control over which parts of the navmesh different agents can traverse.

Using navMeshCreateParams you can access all information you might need about the polys being processed.

Example:

const tileCacheMeshProcess: TileCacheMeshProcess = (navMeshCreateParams: NavMeshCreateParams, polyAreas: UnsignedCharArray, polyFlags: UnsignedShortArray) => {
  const STAIRS_AREA = 1;
  const DEFAULT_AREA = 0;
  const WALK_FLAG = 1;
  const STAIRS_FLAG = 2;

  const vertsCount = navMeshCreateParams.vertCount();
  const indicesCount = navMeshCreateParams.polyCount() * 3;

  for (let i = 0; i < polyAreas.length; i++) {
    // compute average y of polygon vertices
    const idx0 = navMeshCreateParams.polys(i * 3 + 0);
    const idx1 = navMeshCreateParams.polys(i * 3 + 1);
    const idx2 = navMeshCreateParams.polys(i * 3 + 2);

    const avgY = (navMeshCreateParams.verts(idx0 * 3 + 1) + navMeshCreateParams.verts(idx1 * 3 + 1) + navMeshCreateParams.verts(idx2 * 3 + 1)) / 3;

    if (avgY > 1.5) {
      polyAreas[i] = STAIRS_AREA;
      polyFlags[i] = STAIRS_FLAG;
    } else {
      polyAreas[i] = DEFAULT_AREA;
      polyFlags[i] = WALK_FLAG;
    }
  }
};

// Use when creating navmesh
navigationPlugin.createNavMesh(meshes, {
  maxObstacles: 64,
  expectedLayersPerTile: 2,
  tileCacheMeshProcess,
});

List of available functions in NavMeshCreateParams used with TileCacheMeshProcess

setPolyMeshCreateParams(polyMesh: RecastPolyMesh): void;
setPolyMeshDetailCreateParams(polyMeshDetail: RecastPolyMeshDetail): void;
setOffMeshConnections(offMeshConnections: OffMeshConnectionParams[]): void;
verts(index: number): number;
setVerts(index: number, value: number): void;
vertCount(): number;
polys(index: number): number;
setPolys(index: number, value: number): void;
polyAreas(index: number): number;
setPolyAreas(index: number, value: number): void;
polyFlags(index: number): number;
setPolyFlags(index: number, value: number): void;
polyCount(): number;
nvp(): number;
setNvp(value: number): void;
detailMeshes(index: number): number;
setDetailMeshes(index: number, value: number): void;
detailVerts(index: number): number;
setDetailVerts(index: number, value: number): void;
detailVertsCount(): number;
detailTris(index: number): number;
setDetailTris(index: number, value: number): void;
detailTriCount(): number;
offMeshConVerts(index: number): number;
offMeshConRad(index: number): number;
offMeshConDir(index: number): number;
offMeshConAreas(index: number): number;
offMeshConFlags(index: number): number;
offMeshConUserID(index: number): number;
offMeshConCount(): number;
userId(): number;
tileX(): number;
setTileX(value: number): void;
tileY(): number;
setTileY(value: number): void;
tileLayer(): number;
setTileLayer(value: number): void;
boundsMin(): Vector3Tuple;
setBoundsMin(value: Vector3Tuple): void;
boundsMax(): Vector3Tuple;
setBoundsMax(value: Vector3Tuple): void;
walkableHeight(): number;
setWalkableHeight(value: number): void;
walkableRadius(): number;
setWalkableRadius(value: number): void;
walkableClimb(): number;
setWalkableClimb(value: number): void;
cellSize(): number;
setCellSize(value: number): void;
cellHeight(): number;
setCellHeight(value: number): void;
buildBvTree(): boolean;
setBuildBvTree(value: boolean): void;

For detailed information, refer to the recast-navigation-js docs.