Hey everyone, its been a week since i am trying to make a car simulation game while learning jmonkey3 engine altogether. I have ran testFancyCar.java on Ferrari model from Monkeyzone.I thought it is the same model that was used for testFancyCar.java . But the thing is car is accelerating backwards as well as wheels are rotating around the car instead of about themselves. Please if someone uunderstands the problem. I would be thankful 
here is the testFancycar code i am using
package mygame;
import com.jme3.app.SimpleApplication;
import com.jme3.bounding.BoundingBox;
import com.jme3.bullet.BulletAppState;
import com.jme3.bullet.collision.shapes.CollisionShape;
import com.jme3.bullet.control.VehicleControl;
import com.jme3.bullet.objects.VehicleWheel;
import com.jme3.bullet.util.CollisionShapeFactory;
import com.jme3.input.KeyInput;
import com.jme3.input.controls.ActionListener;
import com.jme3.input.controls.KeyTrigger;
import com.jme3.light.DirectionalLight;
import com.jme3.material.Material;
import com.jme3.math.ColorRGBA;
import com.jme3.math.FastMath;
import com.jme3.math.Matrix3f;
import com.jme3.math.Vector3f;
import com.jme3.renderer.RenderManager;
import com.jme3.renderer.queue.RenderQueue;
import com.jme3.scene.Geometry;
import com.jme3.scene.Node;
import com.jme3.scene.Spatial;
import com.jme3.scene.shape.Box;
import com.jme3.shadow.BasicShadowRenderer;
/**
* test
* @author normenhansen
*/
public class Main extends SimpleApplication implements ActionListener {
private BulletAppState bulletAppState;
private VehicleControl player;
private VehicleWheel fr, fl, br, bl;
private Node node_fr, node_fl, node_br, node_bl;
private float wheelRadius;
private float steeringValue = 0;
private float accelerationValue = 0;
private Node carNode;
public static void main(String[] args) {
Main app = new Main();
app.start();
}
@Override
public void simpleInitApp() {
Box b = new Box(1, 1, 1);
bulletAppState = new BulletAppState();
stateManager.attach(bulletAppState);
// bulletAppState.getPhysicsSpace().enableDebug(assetManager);
if (settings.getRenderer().startsWith("LWJGL")) {
BasicShadowRenderer bsr = new BasicShadowRenderer(assetManager, 512);
bsr.setDirection(new Vector3f(-0.5f, -0.3f, -0.3f).normalizeLocal());
viewPort.addProcessor(bsr);
}
cam.setFrustumFar(150f);
flyCam.setMoveSpeed(10);
setupKeys();
PhysicsTestHelper.createPhysicsTestWorld(rootNode, assetManager, bulletAppState.getPhysicsSpace());
// setupFloor();
buildPlayer();
DirectionalLight dl = new DirectionalLight();
dl.setDirection(new Vector3f(-0.5f, -1f, -0.3f).normalizeLocal());
rootNode.addLight(dl);
dl = new DirectionalLight();
dl.setDirection(new Vector3f(0.5f, -0.1f, 0.3f).normalizeLocal());
rootNode.addLight(dl);
}
@Override
public void simpleUpdate(float tpf) {
//TODO: add update code
}
@Override
public void simpleRender(RenderManager rm) {
//TODO: add render code
}
private void setupKeys() {
inputManager.addMapping("Lefts", new KeyTrigger(KeyInput.KEY_H));
inputManager.addMapping("Rights", new KeyTrigger(KeyInput.KEY_K));
inputManager.addMapping("Ups", new KeyTrigger(KeyInput.KEY_U));
inputManager.addMapping("Downs", new KeyTrigger(KeyInput.KEY_J));
inputManager.addMapping("Space", new KeyTrigger(KeyInput.KEY_SPACE));
inputManager.addMapping("Reset", new KeyTrigger(KeyInput.KEY_RETURN));
inputManager.addListener(this, "Lefts");
inputManager.addListener(this, "Rights");
inputManager.addListener(this, "Ups");
inputManager.addListener(this, "Downs");
inputManager.addListener(this, "Space");
inputManager.addListener(this, "Reset");
}
public void onAction(String binding, boolean value, float tpf) {
if (binding.equals("Lefts")) {
if (value) {
steeringValue += .5f;
} else {
steeringValue += -.5f;
}
player.steer(steeringValue);
} else if (binding.equals("Rights")) {
if (value) {
steeringValue += -.5f;
} else {
steeringValue += .5f;
}
player.steer(steeringValue);
} //note that our fancy car actually goes backwards..
else if (binding.equals("Ups")) {
if (value) {
accelerationValue += 800;
} else {
accelerationValue -= 800;
}
player.accelerate(accelerationValue);
player.setCollisionShape(CollisionShapeFactory.createDynamicMeshShape(findGeom(carNode, "Car")));
} else if (binding.equals("Downs")) {
if (value) {
player.brake(40f);
} else {
player.brake(0f);
}
} else if (binding.equals("Reset")) {
if (value) {
System.out.println("Reset");
player.setPhysicsLocation(Vector3f.ZERO);
player.setPhysicsRotation(new Matrix3f());
player.setLinearVelocity(Vector3f.ZERO);
player.setAngularVelocity(Vector3f.ZERO);
player.resetSuspension();
} else {
}
}
}
private Geometry findGeom(Spatial spatial, String name) {
if (spatial instanceof Node) {
Node node = (Node) spatial;
for (int i = 0; i < node.getQuantity(); i++) {
Spatial child = node.getChild(i);
Geometry result = findGeom(child, name);
if (result != null) {
return result;
}
}
} else if (spatial instanceof Geometry) {
if (spatial.getName().startsWith(name)) {
return (Geometry) spatial;
}
}
return null;
}
private void buildPlayer() {
float stiffness = 120.0f;//200=f1 car
float compValue = 0.2f; //(lower than damp!)
float dampValue = 0.3f;
final float mass = 400;
//Load model and get chassis Geometry
carNode = (Node)assetManager.loadModel("Models/Ferrari/Car.j3o");
carNode.setShadowMode(RenderQueue.ShadowMode.Cast);
Geometry chasis = findGeom(carNode, "Car");
BoundingBox box = (BoundingBox) chasis.getModelBound();
//Create a hull collision shape for the chassis
CollisionShape carHull = CollisionShapeFactory.createDynamicMeshShape(chasis);
//Create a vehicle control
player = new VehicleControl(carHull, mass);
carNode.addControl(player);
//Setting default values for wheels
player.setSuspensionCompression(compValue * 2.0f * FastMath.sqrt(stiffness));
player.setSuspensionDamping(dampValue * 2.0f * FastMath.sqrt(stiffness));
player.setSuspensionStiffness(stiffness);
player.setMaxSuspensionForce(10000);
//Create four wheels and add them at their locations
//note that our fancy car actually goes backwards..
Vector3f wheelDirection = new Vector3f(0, -1, 0);
Vector3f wheelAxle = new Vector3f(-1, 0, 0);
Geometry wheel_fr = findGeom(carNode, "WheelFrontRight");
wheel_fr.center();
box = (BoundingBox) wheel_fr.getModelBound();
wheelRadius = box.getYExtent();
float back_wheel_h = (wheelRadius * 1.7f) - 1f;
float front_wheel_h = (wheelRadius * 1.9f) - 1f;
//chasis
player.addWheel(wheel_fr.getParent(), box.getCenter().add(0, -front_wheel_h/2, 0),
wheelDirection, wheelAxle, 0.2f, wheelRadius, true);
Geometry wheel_fl = findGeom(carNode, "WheelFrontLeft");
wheel_fl.center();
box = (BoundingBox) wheel_fl.getModelBound();
player.addWheel(wheel_fl.getParent(), box.getCenter().add(0, -front_wheel_h/2, 0),
wheelDirection, wheelAxle, 0.2f, wheelRadius, true);
Geometry wheel_br = findGeom(carNode, "WheelBackRight");
wheel_br.center();
box = (BoundingBox) wheel_br.getModelBound();
player.addWheel(wheel_br.getParent(), box.getCenter().add(0, -back_wheel_h/2, 0),
wheelDirection, wheelAxle, 0.2f, wheelRadius, false);
Geometry wheel_bl = findGeom(carNode, "WheelBackLeft");
wheel_bl.center();
box = (BoundingBox) wheel_bl.getModelBound();
player.addWheel(wheel_bl.getParent(), box.getCenter().add(0, -back_wheel_h/2, 0),
wheelDirection, wheelAxle, 0.2f, wheelRadius, false);
// player.getWheel(2).setFrictionSlip(4);
// player.getWheel(3).setFrictionSlip(4);
rootNode.attachChild(carNode);
bulletAppState.getPhysicsSpace().add(player);
}
}
