b3dMeshDepth

Returns mesh bounding box depth (Z-axis extent). Takes entity (mesh entity handle). Returns depth as double (maxZ - minZ), 0.0 if invalid/empty mesh. Validates entity exists and is mesh type, iterates all vertices to find min/max Z coordinates, calculates depth as difference. Measures mesh geometry (not world space size, ignores entity transform).

This function calculates mesh depth from vertex data. Bounding box calculation: iterates all vertices in mesh (across all surfaces), finds minimum and maximum Z coordinates: minZ = min(vertex.position.z for all vertices), maxZ = max(vertex.position.z for all vertices), depth = maxZ - minZ. Mesh local space: measures geometry in mesh local space (before entity transform applied), ignores entity position/rotation/scale, measures raw mesh dimensions. Z-axis orientation: measures along forward/backward axis (Z=forward in user space), result is absolute depth value (always positive). Use case: determine mesh front-to-back size for placement/collision, validate model dimensions, procedural sizing, culling calculations. Empty mesh: returns 0.0 if no vertices. Invalid handle: returns 0.0 if entity doesn't exist or isn't mesh type (with error message to stderr). Depth vs world size: b3dMeshDepth measures geometry dimensions, for world-space depth multiply by entity scaleZ: worldDepth = b3dMeshDepth(entity) * b3dGetEntityScaleZ(entity). Zero depth: returns 0.0 for flat meshes (all vertices have same Z coordinate, degenerate geometry like lines/points on XY plane, billboard sprites). Performance: O(N) where N=total vertex count (iterates all vertices once), cached vertex data (no GPU readback), fast operation. Typical usage: depth = b3dMeshDepth(entity) to measure mesh, or check forward extent after generation, or calculate scale factors for fitting. Related: b3dMeshWidth measures X-axis extent (width), b3dMeshHeight measures Y-axis extent (height), b3dGetMeshBoundsMin/Max return full bounding box corners, b3dFitMesh scales mesh to fit target dimensions.