private static void setUpPhysics() {
BroadphaseInterface broadphase = new DbvtBroadphase();
CollisionConfiguration collisionConfiguration = new DefaultCollisionConfiguration();
CollisionDispatcher dispatcher = new CollisionDispatcher(collisionConfiguration);
ConstraintSolver solver = new SequentialImpulseConstraintSolver();
dynamicsWorld = new DiscreteDynamicsWorld(dispatcher, broadphase, solver, collisionConfiguration);
dynamicsWorld.setGravity(new Vector3f(0, -10 /* m/s2 */, 0));
CollisionShape groundShape = new StaticPlaneShape(new Vector3f(0, 1, 0), 0.25f /* m */);
CollisionShape ballShape = new SphereShape(3.0f);
MotionState groundMotionState = new DefaultMotionState(new Transform(new Matrix4f(