physics-manager.md

3D Physics Manager

The 3D Physics System can simulate real physics behavior for collision detection and calculation of the force of the object, and then feed the simulation result back to the rendering layer.

Enable the Physics System

The 3D Physics System is disabled by default. If you need to use it, you can enable it through the following command line, otherwise it will have no effect in runtime.

cc.director.getPhysics3DManager().enabled = true;

Physics System Properties

Properties	Function explanation
enabled	Whether to enable the physics system, default is false
allowSleep	Whether to allow the physics system to automatically hibernate, default is true.
maxSubStep	The maximum number of sub-steps a full step is permitted to be broken into, default is 2.
deltaTime	Time spent in each simulation of physics, default is 1/60s.
gravity	Gravity value of the physics simulation, default is (0, -10, 0)

For API interface, please refer to Physics3DManager for details.

Note: The Builtin Physics Engine does not support the above properties related to physics simulation.

Ray Detection

Ray Detection is used to detect which colliders a given line passes through. There are two types:

• cc.director.getPhysics3DManager().raycast

  The cc.director.getPhysics3DManager().raycast interface, will detect all Colliders on the ray path, the order of the detected results is not fixed.

  • If no Collider is detected, it returns null.
  • If so, it returns an array containing the results of all Collisions. Please refer to the raycast for details.

  Code example:

  onTouchStart (event) {
      let touchLoc = event.touch.getLocation();
      let ray = cc.Camera.main.getRay(touchLoc);
      let maxDistance = 1000;
      let rayColliderGroupName = "ray collider group name";
      const results = cc.director.getPhysics3DManager().raycast(ray, rayColliderGroupName, maxDistance);
      if (results) {
          console.log(results);
      }
  }

• cc.director.getPhysics3DManager().raycastClosest

  The cc.director.getPhysics3DManager().raycastClosest interface, will detect the nearest Collider on the ray path.

  • If no Collider is detected, it returns null.
  • If so, it returns a Collider that meets the requirements, the usage is similar to the raycast. Please refer to the raycastClosest for details.

  Code example:

  onTouchStart (event) {
      let touchLoc = event.touch.getLocation();
      let ray = cc.Camera.main.getRay(touchLoc);
      let maxDistance = 1000;
      let rayColliderGroupName = "ray collider group name";
      const result = cc.director.getPhysics3DManager().raycastClosest(ray, rayColliderGroupName, maxDistance);
      if (result) {
          console.log(result);
      }
  }