private void buildPlayer() {
        Material mat = new Material(getAssetManager(), "Common/MatDefs/Misc/Unshaded.j3md");
        mat.getAdditionalRenderState().setWireframe(true);
        mat.setColor("Color", ColorRGBA.Red);

        //create a compound shape and attach the BoxCollisionShape for the car body at 0,1,0
        //this shifts the effective center of mass of the BoxCollisionShape to 0,-1,0
        CompoundCollisionShape compoundShape = new CompoundCollisionShape();
        BoxCollisionShape box = new BoxCollisionShape(new Vector3f(1.2f, 0.5f, 2.4f));
        compoundShape.addChildShape(box, new Vector3f(0, 1, 0));

        //create vehicle node
        Node vehicleNode=new Node("vehicleNode");
        vehicle = new VehicleControl(compoundShape, 800);
        vehicleNode.addControl(vehicle);

        //setting suspension values for wheels, this can be a bit tricky
        //see also https://docs.google.com/Doc?docid=0AXVUZ5xw6XpKZGNuZG56a3FfMzU0Z2NyZnF4Zmo&hl=en
        float stiffness = 60.0f;//200=f1 car
        float compValue = .3f; //(should be lower than damp)
        float dampValue = .4f;
        vehicle.setSuspensionCompression(compValue * 2.0f * FastMath.sqrt(stiffness));
        vehicle.setSuspensionDamping(dampValue * 2.0f * FastMath.sqrt(stiffness));
        vehicle.setSuspensionStiffness(stiffness);
        vehicle.setMaxSuspensionForce(10000.0f);

        //Create four wheels and add them at their locations
        Vector3f wheelDirection = new Vector3f(0, -1, 0); // was 0, -1, 0
        Vector3f wheelAxle = new Vector3f(-1, 0, 0); // was -1, 0, 0
        float radius = 0.5f;
        float restLength = 0.3f;
        float yOff = 0.5f;
        float xOff = 1f;
        float zOff = 2f;

        Cylinder wheelMesh = new Cylinder(16, 16, radius, radius * 0.6f, true);

        Node node1 = new Node("wheel 1 node");
        Geometry wheels1 = new Geometry("wheel 1", wheelMesh);
        node1.attachChild(wheels1);
        wheels1.rotate(0, FastMath.HALF_PI, 0);
        wheels1.setMaterial(mat);
        vehicle.addWheel(node1, new Vector3f(-xOff, yOff, zOff),
                wheelDirection, wheelAxle, restLength, radius, true);

        Node node2 = new Node("wheel 2 node");
        Geometry wheels2 = new Geometry("wheel 2", wheelMesh);
        node2.attachChild(wheels2);
        wheels2.rotate(0, FastMath.HALF_PI, 0);
        wheels2.setMaterial(mat);
        vehicle.addWheel(node2, new Vector3f(xOff, yOff, zOff),
                wheelDirection, wheelAxle, restLength, radius, true);

        Node node3 = new Node("wheel 3 node");
        Geometry wheels3 = new Geometry("wheel 3", wheelMesh);
        node3.attachChild(wheels3);
        wheels3.rotate(0, FastMath.HALF_PI, 0);
        wheels3.setMaterial(mat);
        vehicle.addWheel(node3, new Vector3f(-xOff, yOff, -zOff),
                wheelDirection, wheelAxle, restLength, radius, false);

        Node node4 = new Node("wheel 4 node");
        Geometry wheels4 = new Geometry("wheel 4", wheelMesh);
        node4.attachChild(wheels4);
        wheels4.rotate(0, FastMath.HALF_PI, 0);
        wheels4.setMaterial(mat);
        vehicle.addWheel(node4, new Vector3f(xOff, yOff, -zOff),
                wheelDirection, wheelAxle, restLength, radius, false);

        vehicleNode.attachChild(node1);
        vehicleNode.attachChild(node2);
        vehicleNode.attachChild(node3);
        vehicleNode.attachChild(node4);

        rootNode.attachChild(vehicleNode);
        getPhysicsSpace().add(vehicle);

        //driver
        Node driverNode=new Node("driverNode");
        driverNode.setLocalTranslation(0,2,0);
        RigidBodyControl driver
                = new RigidBodyControl(new BoxCollisionShape(new Vector3f(0.2f,.5f,0.2f)));
        driverNode.addControl(driver);

        rootNode.attachChild(driverNode);
        getPhysicsSpace().add(driver);

        //joint
        slider=new SliderJoint(driver, vehicle, Vector3f.UNIT_Y.negate(), Vector3f.UNIT_Y, true);
        slider.setUpperLinLimit(.1f);
        slider.setLowerLinLimit(-.1f);

        getPhysicsSpace().add(slider);

        Node pole1Node=new Node("pole1Node");
        Node pole2Node=new Node("pole1Node");
        Node bridgeNode=new Node("pole1Node");
        pole1Node.setLocalTranslation(new Vector3f(-2,-1,4));
        pole2Node.setLocalTranslation(new Vector3f(2,-1,4));
        bridgeNode.setLocalTranslation(new Vector3f(0,1.4f,4));

        RigidBodyControl pole1=new RigidBodyControl(new BoxCollisionShape(new Vector3f(0.2f,1.25f,0.2f)),0);
        pole1Node.addControl(pole1);
        RigidBodyControl pole2=new RigidBodyControl(new BoxCollisionShape(new Vector3f(0.2f,1.25f,0.2f)),0);
        pole2Node.addControl(pole2);
        bridge=new RigidBodyControl(new BoxCollisionShape(new Vector3f(2.5f,0.2f,0.2f)));
        bridgeNode.addControl(bridge);

        rootNode.attachChild(pole1Node);
        rootNode.attachChild(pole2Node);
        rootNode.attachChild(bridgeNode);
        getPhysicsSpace().add(pole1);
        getPhysicsSpace().add(pole2);
        getPhysicsSpace().add(bridge);

    }
Tests attaching/detaching nodes via joints
@author normenhansen
jme3-examples/src/main/java/jme3test/bullet/TestAttachDriver.java