This adds detailed comments documenting each step involved in computing the interaction transform used in the PositionProp. The corresponding code was initially introduced in commit 503ef1d ("ENH: Add VR interactor style class for transforming objects in MRML", 2018-08-31).
Since the previous attempt at addressing the issue was incorrect^1, another approach suggested by @LucasGandel would be to review the implementation of similar computation used in vtkInteractorStyle3D::PositionProp^2 function.
This adds detailed comments documenting each step involved in computing the interaction transform used in the PositionProp. The corresponding code was initially introduced in commit 503ef1d ("ENH: Add VR interactor style class for transforming objects in MRML", 2018-08-31).