First off, thanks for the great work, and for making this project open source! My team plans to contribute some modifications and (slight!) improvements in the near future. We built a North Star and added an HTC Vive Tracker for positional, world-space tracking. With the Leap Motion, hand tracking and hand-locked objects work great, but we're having trouble getting world-locked objects to work. Currently we're getting the position and rotation of the tracker, adding a position and rotation offset, and then setting the ARCameraRig position and rotation to that. It kind of works, but the alignment is not great, and there is quite a bit of drift. Can you offer any tips for how you implemented tracking using the OptiTrack system?