Callbacks & Events

Scene Update

Because Physijs runs on a different thread than your main application, there is no guarantee that it will be able to iterate the scene every time you call scene.simulate. Because of this, you may attach an event listener to the scene that is triggered whenever the physics simulation has run.

var scene = new Physijs.scene;
scene.addEventListener( 'update', function() {
    // the scene's physics have finished updating
});

Collisions

To be notified when an object experiences a collision with another object, you can attach a collision event listener to individual objects.

var mesh = new Physijs.BoxMesh( geometry, material );
mesh.addEventListener( 'collision', function( other_object, linear_velocity, angular_velocity ) {
    // `this` is the mesh with the event listener
    // other_object is the object `this` collided with
    // linear_velocity and angular_velocity are floats representing the relative velocities of the impact
});

Adding an object

If your scene is complex or has a lot of objects, the physics simulation can slow down to the point where adding new objects can become a lot of work for the application. To help alleviate some of the pain this may cause, the scene.add method takes an optional callback function for a second parameter. This function will be called after the object has been added to the scene. This can be seen in many of the examples in order to avoid flooding the scene with new objects as the simulation slows down.

var mesh = new Physijs.SphereMesh( geometry, material );
scene.add( mesh, function() {
    // object has been added to the scene
});