prepareBreakableObject( object, mass, velocity, angularVelocity, breakable ) {

		// object is a Object3d (normally a Mesh), must have a buffer geometry, and it must be convex.
		// Its material property is propagated to its children (sub-pieces)
		// mass must be > 0

		const userData = object.userData;
		userData.mass = mass;
		userData.velocity = velocity.clone();
		userData.angularVelocity = angularVelocity.clone();
		userData.breakable = breakable;

	}
Must be called for all 3D objects that should be breakable.

@param {Object3D} object - The 3D object. It must have a convex geometry.
@param {number} mass - The 3D object's mass in kg. Must be greater than `0`.
@param {Vector3} velocity - The 3D object's velocity.
@param {Vector3} angularVelocity - The 3D object's angular velocity.
@param {boolean} breakable - Whether the 3D object is breakable or not.