TwoGrabRotateTransformer Class
A Transformer that rotates the target about an axis, given two grab points.
Updates apply relative rotational changes, relative to the angle change between the two grab points each frame. The axis is defined by a pivot transform: a world position and up vector.
Transform PivotTransform[Get]
void InjectOptionalPivotTransform ( Transform pivotTransform )
void InjectOptionalRotationAxis ( Axis rotationAxis )
void InjectOptionalConstraints 
