Torque forces help

Troubleshooting physics
1

Hi, I just decide to change my kinematic ship to be an rigidbody ship. Its using joints to simulate fixed orbit around a planet.
Then I found out a odd behavior when it reaches some positions in space, it seems it just remove all torque forces and then invert it…
I am using obj.applyTorque(new Vector3f(0,1,0)) , but I also tried to change the vector to the foward+90º from the ship, didnt work…
I just built an test case for it, and made this image of the positions…
I am not sure if this is a bug, an problem in my code, an problem with joints, or an misunderstanding on how torque works, so if anyone that knows it better could clarify me I appreciate.

http://s24.postimg.org/4mtya5xad/torquebug.png

public class RestrictionTest extends SimpleApplication implements PhysicsTickListener {

private BulletAppState bulletAppState;

private boolean keyup,keyleft,keyright,keydown;
private Node coneObjNode;
private ConeJoint conejoint;

public RestrictionTest() {super(null);}
public static void main(String[] args) { new RestrictionTest().start(); }

@Override public void simpleInitApp() {
    bulletAppState = new BulletAppState();
    stateManager.attach(bulletAppState);
    bulletAppState.getPhysicsSpace().setGravity(Vector3f.ZERO);
    bulletAppState.getPhysicsSpace().enableDebug(assetManager);

    Node centerConeNode=new Node();   centerConeNode.setLocalTranslation(0, -0, 0f);
    coneObjNode=new Node();      coneObjNode.setLocalTranslation(0,-2f,0f);
    BoxCollisionShape collisionShape = new BoxCollisionShape(new Vector3f( .3f, .3f, .3f));
    conejoint = Utils.createConeJoint(centerConeNode, coneObjNode, collisionShape, 1, bulletAppState);
    rootNode.attachChild(centerConeNode); rootNode.attachChild(coneObjNode);
    bulletAppState.getPhysicsSpace().add(conejoint);

    // *******************
    // Front Debug Arrow
    Material mFoward = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
    Vector3f directionFoward = new Vector3f(0, 0, 1f);
    Arrow arrowFoward = new Arrow(directionFoward); arrowFoward.setLineWidth(2);  Geometry gArrowFoward = new Geometry("aaa",arrowFoward);
    mFoward.setColor("Color", ColorRGBA.Gray); gArrowFoward.setMaterial(mFoward);
    coneObjNode.attachChild(gArrowFoward);

    // *******************
    // Right Debug Arrow
    Material mRight = new Material(assetManager, "Common/MatDefs/Misc/Unshaded.j3md");
    Vector3f directionRight = new Vector3f(1, 0, 0);
    Arrow arrowRight = new Arrow(directionRight); arrowRight.setLineWidth(2);  Geometry gArrowRight = new Geometry("aaa",arrowRight);
    mRight.setColor("Color", ColorRGBA.Red); gArrowRight.setMaterial(mRight);
    coneObjNode.attachChild(gArrowRight);

    conejoint.getBodyB().setDamping(0.5f, 0.9f);

    inputManager.addMapping("left", new KeyTrigger(KeyInput.KEY_LEFT));     inputManager.addMapping("left", new KeyTrigger(KeyInput.KEY_A ));
    inputManager.addMapping("right", new KeyTrigger(KeyInput.KEY_RIGHT));   inputManager.addMapping("right", new KeyTrigger(KeyInput.KEY_D));
    inputManager.addMapping("up", new KeyTrigger(KeyInput.KEY_UP));         inputManager.addMapping("up", new KeyTrigger(KeyInput.KEY_W));
    inputManager.addMapping("down", new KeyTrigger(KeyInput.KEY_DOWN));     inputManager.addMapping("down", new KeyTrigger(KeyInput.KEY_S));
    inputManager.addListener(actionListener, "up","left","right","down");

    bulletAppState.getPhysicsSpace().addTickListener(this);
}


private ActionListener actionListener = new ActionListener() {
    public void onAction(String name, boolean keyPressed, float tpf) {
        if (name.equals("up"))       keyup=keyPressed;
        if (name.equals("left"))     keyleft=keyPressed;
        if (name.equals("right"))    keyright=keyPressed;
        if (name.equals("down"))     keydown=keyPressed;
    }
};

public void prePhysicsTick(PhysicsSpace space, float tpf) {
    Quaternion fixit = conejoint.getBodyA().getPhysicsRotation();
    fixit.lookAt(coneObjNode.getWorldTranslation(), Utils.getForwardVector(coneObjNode)  );
    conejoint.getBodyA().setPhysicsRotation(fixit);

    Vector3f foward = Utils.getForwardVector((Node)coneObjNode);
    PhysicsRigidBody obj = conejoint.getBodyB();

    if (keyup)   { obj.applyForce(foward, coneObjNode.getWorldTranslation() ); }
    if (keydown) { obj.applyForce(foward.negate(), coneObjNode.getWorldTranslation() ); }
    if(keyleft)  { obj.applyTorque(new Vector3f(0,1,0));  }
    if(keyright) { obj.applyTorque(new Vector3f(0,-1,0)); }
}

public void physicsTick(PhysicsSpace space, float tpf) { }

}

2

I found a topic on bullet forum that seens to be related :

http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?t=8153
http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?f=9&t=4457

But I am not sure how to implement this fix, anyone knows how to convert it ?
Obs: I am using Conejoint, but tis easy to change to 6Dof if it fix it. Also, I have tried 6Dof and it has the same behavior from conejoint.

3

Here is the code from Utils, I forgot to past. It will be required to test it :

public static ConeJoint createConeJoint(Node a, Node b, CollisionShape bshape, float mass, BulletAppState bulletAppState ) {
    // As its a simple free joint, origem shape is a simple stoped box
    RigidBodyControl rigidbox = new RigidBodyControl(new BoxCollisionShape(new Vector3f( .1f, .1f, .1f)), 0);
    rigidbox.setPhysicsLocation( a.getLocalTranslation() );
    a.addControl(rigidbox); bulletAppState.getPhysicsSpace().add(a);

    // Destiny will have a determined shape
    RigidBodyControl rigidbody = new RigidBodyControl(bshape, mass);
    rigidbody.setPhysicsLocation( b.getLocalTranslation() );
    b.addControl(rigidbody); bulletAppState.getPhysicsSpace().add(b);

    // Return this conejoint, control point is the origem Node center of mass
    ConeJoint thisconejoint = createConeJointJoin(a, b, a.getLocalTranslation());
    return thisconejoint;
}

// PRIVATE - Work with createFreeJoint
private  static ConeJoint createConeJointJoin(Node A, Node B, Vector3f connectionPoint) {
    Vector3f pivotA = A.worldToLocal(connectionPoint, new Vector3f());
    Vector3f pivotB = B.worldToLocal(connectionPoint, new Vector3f());
    ConeJoint joint = new ConeJoint(A.getControl(RigidBodyControl.class), B.getControl(RigidBodyControl.class), pivotA, pivotB);
    return joint;
}

// Create a Joint of the orbit type
public static SixDofJoint createFreeJointSixDof(Node a, Node b, CollisionShape bshape, float mass, BulletAppState bulletAppState ) {
    // As its a simple free joint, origem shape is a simple stoped box
    RigidBodyControl rigidbox = new RigidBodyControl(new BoxCollisionShape(new Vector3f( .1f, .1f, .1f)), 0);
    rigidbox.setPhysicsLocation( a.getLocalTranslation() );
    a.addControl(rigidbox); bulletAppState.getPhysicsSpace().add(a);

    // Destiny will have a determined shape
    RigidBodyControl rigidbody = new RigidBodyControl(bshape, mass);
    rigidbody.setPhysicsLocation( b.getLocalTranslation() );
    b.addControl(rigidbody); bulletAppState.getPhysicsSpace().add(b);

    // Return this SixDofJoint, control point is the origem Node center of mass
    SixDofJoint thisjoint = createFreeJointJoinSixDof(a, b, a.getLocalTranslation());
    return thisjoint;
}

// PRIVATE - Work with createFreeJoint
public  static SixDofJoint createFreeJointJoinSixDof(Node A, Node B, Vector3f connectionPoint) {
    Vector3f pivotA = A.worldToLocal(connectionPoint, new Vector3f());
    Vector3f pivotB = B.worldToLocal(connectionPoint, new Vector3f());
    SixDofJoint joint = new SixDofJoint(A.getControl(RigidBodyControl.class), B.getControl(RigidBodyControl.class), pivotA, pivotB,false);
    //joint.setAngularLowerLimit(new Vector3f(0, 0, 0));
    //joint.setLinearUpperLimit(0,13,0); //setAngularUpperLimit(new Vector3f(Float.POSITIVE_INFINITY, Float.POSITIVE_INFINITY, Float.POSITIVE_INFINITY));
    return joint;
}
4

No one ?
I guess its another problem with bullet x engine with no explanation or solution ?

5

are you using native Bullet or jBullet ?

6

JBullet on Jm3…
I guess there is a problem in the joints, probably its in the Bullet side.
I tried to use all joint types available, all have the same problem.
I could not find any solution for this yet…