[BUG] ObjectManipulator rotation is inverted in some cases with constraint on two axes

[NoTuxNoBux]

Describe the bug

This is basically microsoft/MixedRealityToolkit-Unity#8947 from the MRTK2, but for the MRTK3 - the original issue was closed because of the MRTK2 being retired, but I also seem to be experiencing a similar issue in the MRTK3 with a similar setup.

To reproduce

See also the original issue's reproduction steps, my setup is very similar:

1. Have a 3D object such as a cube with the necessary collider on it.
2. Set an ObjectManipulator on it.
3. Configure an AxisRotationConstraint to restrict the X and Z axes (so you can only rotate from 'left to right' or over the Y axis). Keep Hand Type and Proximity Type on Everything, don't enable Use Local Space For Constraint.
4. When using a single hand to move the object left and right in play mode, moving your hand left after grabbing rotates the object right and the other way around.

In my case I have an object that was rotated 180º so I first suspected that was causing it, but it wasn't.

Expected behavior

The inverse happens; moving hand left rotates the object left as well.

Your setup (please complete the following information)

• Unity Version: 6000.0.11f1
• MRTK Version or Commit: 3.2.0.

Target platform (please complete the following information)

• Meta Quest 3
• Meta XR

Additional context

I was able to create my own RotateLogic and attach it to the ObjectManipulator to fix the issue:

public sealed class ObjectManipulatorReversedRotateLogic : ManipulationLogic<Quaternion>
{
    private Vector3 startHandlebar;
    private Quaternion startInputRotation;
    private Quaternion startRotation;

    /// <inheritdoc />
    public override void Setup(List<UnityEngine.XR.Interaction.Toolkit.Interactors.IXRSelectInteractor> interactors, UnityEngine.XR.Interaction.Toolkit.Interactables.IXRSelectInteractable interactable, MixedRealityTransform currentTarget)
    {
        base.Setup(interactors, interactable, currentTarget);

        if (NumInteractors >= 2)
        {
            startHandlebar = GetHandlebarDirection(interactors, interactable);
        }

        startInputRotation = interactors[0].GetAttachTransform(interactable).rotation;
        startRotation = currentTarget.Rotation;
    }

    /// <inheritdoc />
    public override Quaternion Update(
        List<UnityEngine.XR.Interaction.Toolkit.Interactors.IXRSelectInteractor> interactors,
        UnityEngine.XR.Interaction.Toolkit.Interactables.IXRSelectInteractable interactable,
        MixedRealityTransform currentTarget,
        bool centeredAnchor)
    {
        base.Update(interactors, interactable, currentTarget, centeredAnchor);

        if (NumInteractors == 1)
        {
            // NOTE: Only this line changed as opposed to the original MRTK RotateLogic.
            return Quaternion.Inverse(interactors[0].GetAttachTransform(interactable).rotation) * startInputRotation * startRotation;
        }
        else
        {
            // TODO: This gimbal locks if you hold an object with two hands and then rotate your body a full 180 degrees.
            return Quaternion.FromToRotation(startHandlebar, GetHandlebarDirection(interactors, interactable)) * startRotation;
        }
    }

    private static Vector3 GetHandlebarDirection(List<UnityEngine.XR.Interaction.Toolkit.Interactors.IXRSelectInteractor> interactors, UnityEngine.XR.Interaction.Toolkit.Interactables.IXRSelectInteractable interactable)
    {
        Debug.Assert(interactors.Count >= 2, $"GetHandlebarDirection called with less than 2 interactors ({interactors.Count}).");
        return interactors[1].GetAttachTransform(interactable).position - interactors[0].GetAttachTransform(interactable).position;
    }
}