(ui-center-origin [origin|bbox-center])Set the origin of the coordinate system of the CENTER object for
user interface (i.e. mouse) controlled motions. The keyword
origin means to use the origin of the coordinate system of the
currently selected object, while bbox-center means to use the
center of the bounding box of the current object. The keyword
bbox-center makes no sense if the geometry is
non-Euclidean. Using either bbox-center or origin does not
make a difference if the center object is not a geometry, e.g. if
it is a camera. Same holds if the World is the currently selected
object.