b3dEntityZ

Returns entity Z position (world space, 0.0 if invalid). Takes entity (entity handle). Returns Z coordinate as Double (entity.position.z, 0.0 if entity doesn't exist). Validates entity exists, returns position.z directly (no Y-axis negation for Z coordinate), returns 0.0 if invalid handle. Query function for entity forward/backward position.

This function retrieves entity Z coordinate. Return value: returns entity.position.z (internal coordinate, same as user coordinate for Z-axis), float converted to double, 0.0 if entity handle invalid. Coordinate system: Z-axis is forward/backward (positive=forward, negative=backward in user space), returned value is world-space position (if parented, value is local to parent). Use cases: (1) Depth queries (check entity front/back position for rendering, collision), (2) Distance calculations (measure forward distance to targets), (3) Boundary checks (trigger zones based on Z position), (4) Navigation (pathfinding, waypoints), (5) Debugging (log forward position). Common pattern: z = b3dEntityZ(entity), if z > zoneBoundary: trigger event, or forwardDist = b3dEntityZ(target) - b3dEntityZ(player). Typical usage: query Z for forward/backward logic (chase AI, trigger zones), combine with X/Y for full 3D position. Position synchronization: if entity has physics body, position synced from physics (entity.position updated from physics body each frame), returned value reflects physics-driven position. Parent relationships: if entity parented, position is local coordinates (relative to parent), returned value is local Z (not world Z, world Z requires parent matrix multiplication). Invalid handle: returns 0.0 for non-existent entities (silent fail), check entity validity separately if 0.0 might be valid position. Performance: O(1) lookup (hash map find, field access, very fast). Related: b3dEntityX returns X position, b3dEntityY returns Y position (with negation), b3dPositionEntity sets position, b3dMoveEntity moves entity.