public void setupJoint() {
Node holderNode = PhysicsTestHelper.createPhysicsTestNode(assetManager, new BoxCollisionShape(new Vector3f(.1f, .1f, .1f)), 0);
holderNode.getControl(RigidBodyControl.class).setPhysicsLocation(new Vector3f(0f, 0, 0f));
rootNode.attachChild(holderNode);
getPhysicsSpace().add(holderNode);
Node hammerNode = PhysicsTestHelper.createPhysicsTestNode(assetManager, new BoxCollisionShape(new Vector3f(.3f, .3f, .3f)), 1);
hammerNode.getControl(RigidBodyControl.class).setPhysicsLocation(new Vector3f(0f, -1, 0f));
rootNode.attachChild(hammerNode);
getPhysicsSpace().add(hammerNode);
collisionNode = PhysicsTestHelper.createPhysicsTestNode(assetManager, new BoxCollisionShape(new Vector3f(.3f, .3f, .3f)), 0);
collisionNode.getControl(RigidBodyControl.class).setPhysicsLocation(new Vector3f(1.8f, 0, 0f));
rootNode.attachChild(collisionNode);
getPhysicsSpace().add(collisionNode);
ghostControl = new GhostControl(new SphereCollisionShape(0.7f));
hammerNode.addControl(ghostControl);
getPhysicsSpace().add(ghostControl);
joint = new HingeJoint(holderNode.getControl(RigidBodyControl.class), hammerNode.getControl(RigidBodyControl.class), Vector3f.ZERO, new Vector3f(0f, -1, 0f), Vector3f.UNIT_Z, Vector3f.UNIT_Z);
getPhysicsSpace().add(joint);
}