[SOLVED] Bullet RigidBodyControl wait until movement is done

Troubleshooting physics
1

Hello, I wonder what is best solution for this.

I have a RigidBodyControl on a person model and I want to make command move from x1=(0,0,0) to x2=(1,0,0) position. I can applyImpulse() to so that the model is moving to the position. But how can I know that the model is done moving to the position?

Is there a listener that says that the body is not moving anymore?

Or do I need to check the physical position of the body and if position=x2 then done?

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2

There is a getLinearVelocity method for finding the current velocity of the object and getAngularVelocity method for finding the amount of current rotation. These are both available on the RigidBodyControl.

getLinearVelocity if I recall returns a direction multiplied by a distance per physics tick in world units. getAngularVelocity returns how much the object is rotating in radians per physics tick.

I’m sure the javadoc will be of help.

3

There’s no listener specifically for positions. Test the position after each physics tick, using a PhysicsTickListener. And don’t use == on vectors or floats!

4

Did you ever arrive at a satisfactory solution?

5

Yes, thank you. I keep track of the object physical location and linear velocity now. Then I can react if the conditions are met.

I’m also use a PhysicsTickListener to move objects, because apply impulse will rotate my model.

@Data
private class MoveObjectInPhysicsSpace implements PhysicsTickListener {

    boolean movementDone = false;

    final RigidBodyControl control;

    final Vector3f target;

    final Vector3f position = new Vector3f();

    final Vector3f velocity = new Vector3f(1f, 0f, 0f);

    @Override
    public void prePhysicsTick(PhysicsSpace space, float tpf) {
        if (position.distanceSquared(target) < 0.1f) {
            movementDone = true;
            control.setLinearVelocity(Vector3f.ZERO);
            physicsSpace.removeTickListener(this);
        }
    }

    @Override
    public void physicsTick(PhysicsSpace space, float tpf) {
        if (movementDone) {
            return;
        }
        control.setLinearVelocity(velocity);
        control.getPhysicsLocation(position);
    }

}
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6

what about RigidBodyControl.isActive() ? maybe you can use that to check when the movement is done…

7

I believe that’s triggered when a rigidbody has been idle for a certain period, not immediately.

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8

Also pretty sure that something can be “active” and not moving if some other object is on it, touching it, etc…