Select morph, click the point you want to rotate from and hold down your mouse button, you can now pick the axis of the rotation.
I don't really like to pick the axis, would prefer to pick the 'plane', so to speak, but this does give you control over the typical 15/30 degree steps.
By default the editing plan is horizontal, you can change this to vertical or any plane of existing elements in 3D.
You can also, much more easily rotate things in section/elevation and plan view. Most tutorials focus on the 3D window (I guess it looks more impressive?), but you can be more productive using well placed sections and elevations and the plan view, in my opinion.
Erwin Edel, Project Lead, Leloup Architecten
www.leloup.nlArchiCAD 9-26NED FULL
Windows 10 Pro
Adobe Design Premium CS5