[Solved] Palm position nowhere near actual palm position

[jquave]

Hey all, I've read a few posts here concerning the deprecation of ToUnity and I see in this post: https://community.leapmotion.com/t/unity-vector-conversion-utility-class-not-working-as-expected/4714/5

Joe mentions using the matrix in LeapProvider.GetLeapMatrix, however this is undefined as far as I can tell, was the name changed?

I have a scene with this code, but in practice the gameObject doesn't appear near the palm, it shows up way off in the distance, the scale seems to be about 1000x too large, roughly.

I feel like it's really not clear even after reading the forums about this exact question, how do I get the Unity Vector3 position of the palm?

void Update () {
    Frame frame = controller.Frame();
    List<Hand> hands = frame.Hands;

    foreach (Hand hand in hands)
    {
        if (hand.IsLeft)
        {
            if (grabObject != null)
            {
                grabObject.transform.position = hand.PalmPosition.ToVector3();


            }
        }
    }

}

[jquave]

I found a working solution. I'm not sure if this is the proper approach and normally would cache the provider, but for simplicity of a code sample... anyone else trying to find the palm position in Orion 4.0.1 can use this:

LeapProvider provider = FindObjectOfType<LeapProvider>() as LeapProvider;
Matrix mat = UnityMatrixExtension.GetLeapMatrix(provider.transform);
grabObject.transform.position = mat.TransformPoint(hand.PalmPosition).ToVector3();

[Joe_Ward]

That should work, but it does duplicate work already done by the provider. If you use Provider.CurrentFrame, you will get the frame object already transformed into the Provider's frame of reference. In other words:

LeapProvider provider = FindObjectOfType<LeapProvider>() as LeapProvider;
foreach (Hand hand in provider.CurrentFrame.Hands)
{
    if (hand.IsLeft)
    {
        if (grabObject != null)
        {
            grabObject.transform.position = hand.PalmPosition.ToVector3();
        }
    }
}

If you get the Frame object directly from Leap.Controller, then you WILL need to handle coordinate conversion and mapping yourself.

[jquave]

Thanks Joe, I wasn't aware of the CurrentFrame property, that is helpful. I simplified my code with this suggestion and it's much cleaner now.

One more question for you, is the normal of the palm the best way to dictate rotation of an object that's being held by the player? I tried using this to make the object feel like it's attached to the player's palm, it mostly works but the object kind of spins as I move my hand around.

    Vector3 palmNormal = hand.PalmNormal.ToVector3();
    grabObject.transform.rotation = Quaternion.FromToRotation(Vector3.up, palmNormal);

[Joe_Ward]

The hand basis is probably better:

grabObject.transform.rotation = hand.Basis.Rotation();