Hi Kevin, it is something that I'd like to add in the future, certainly it could be useful in various situations where you just want to eyeball things. Basically that kind of operation just hasn't been as high of a priority as other stuff yet.

I decided to put more emphasis instead on the edit frame, since that lines up well with 2D editing and drawing and editing 2D curves has been more of the focus area in MoI so far.

One thing that's nice about the edit frame instead of a central manipulator is that you can do some kinds of basic accurate scaling with the edit frame that aren't normally possible with a center type manipulator, like for example here I scale a shape using the edit frame and there is a snap available to make the object scaled by the exact amount to fit between 2 other objects:



Because the edit frame works by operating on the object boundary it enables accurate scaling of areas of the object that are on that boundary line.

Then on top of that the other really big plus about the edit frame is that it's much lower profile than a manipulator widget, instead of taking up a bunch of screen real estate right in the center of things, it instead goes totally around the outside of the current selection and is also sparser as well. That helps make it feasible to keep on all the time rather than having to constantly turn it on and off.

Anyway, those are some of the reasons why I decided to do the edit frame initially instead of one of those other central manipulator types. The other kinds of manipulators do have benefits in other kinds of situations so I think it would make sense to eventually have them as well, I just viewed it as a somewhat lower priority item.

I also have some general concept about maybe having a 3D edit frame that also goes around the outside of the object at corners rather than a center one, but I haven't had time yet to experiment with that. A 3D corner frame may possibly give some of the type of exact scaling functions like I show above with the 2D frame and maybe would have a little bit of the "stay out of the way" properties as well (but maybe not too...).

It could be possible that eventually there might be a 3D frame and also a center type manipulator as well, but I'd probably like to try and see if that can be avoided first.

In the meantime the transform tools under the Transform palette can do a lot of things already like rotate a box around one of its faces as shown previously. Since there is a set of flexible tools for doing those kinds of things that has also made it not a big priority to do a 3D manipulator yet as well.

- Michael