Hi Nigel, there is no way to do this currently in MoI.

That's something that kind of fits in better with a polygon modeler since in a poly modeler your geometry is all made up of little bits of stuff. So that means it is pretty easy for you to make a small sized selection to get a localized rotation point.

In NURBS modeling objects are made up of kind of larger chunks of stuff and broader bigger surfaces and longer curved edges. There is not the same kind of localized little fragmented bits of stuff to select like there is with a poly modeler.

So rotating around the current selection in a NURBS modeler would tend to make it difficult to focus in on a particular area of the model, because your selections would be of larger pieces. Your rotation point would easily be off the current screen when you zoomed in a bit, and when your rotation point is way off of the visible screen it tends to make the view rather hard to control.

I guess at some point in the future I will probably add it in anyway as an option, but I'm not really sure that it will be of the same kind of use as what it would be in a poly modeler.

So anyway, the above is the reason why MoI does not have that ability in it currently.

- Michael