[TRACKER] Port to C++ for Godot Engine

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I'm trying to scope out what needs to be ported for the C++ game engine Godot Engine.

• Port C#? Java to C++
• Make a visualizer for kusudama constraints

The goal is to have realistic IK tracking given three sensors (head-mounted display, two trackers) and at least 3 - 10 VR tracker sensor positions.

My peers had some concerns about FABRIK's unnaturalness around the bending of the elbows, given only three sensor points.

The plan currently is to have analytic solvers for the IK system, but it doesn't have sound theory behind it.

#5 mentioned some calibration needed for scaling the body. We could use a "T" or "A" pose for doing that. Other systems like VRCHAT or HI FIDELITY used the height of the head-mounted display and the hips to give a possible scale. Scaled avatars like huge persons or small persons are a problem.