Bryant Quinney | Applications Expert
You may (or maybe not) have noticed, in AutoCAD (and AutoCAD-based programs) a feature to dynamically change the UCS simply by clicking on it and picking a second point from which to align a UCS axis. Modifying the current UCS by this method removed a bit of typing needed for the time-tested methods found in the UCS command. As it has been, to change the rotation of the UCS (say we want to rotate about the Z-axis) the steps would look a bit like this:
- Execute the UCS command;
- Type Z for the z-axis option;
- Enter the value for the desired rotation. And press ENTER.
Bear in mind, this is now not a mind-blowing change, but if you hover over the UCS icon, you will find that it highlights, signifying the ability to select it. When you do click on it, grips show, allowing you to activate one (make it hot) and choose a rotation angle.
First, the square grip allows up to reposition the UCS origin elsewhere in space by picking a point location, typing coordinates or aligning to a face, surface, or mesh. How is that for removing the typing?
If you hover over a grip on the UCS, you get a pop-up menu that allows you to “Move and Align”, “Move Origin Only”, or reset to “World”. By default, when you select the origin grip, the behavior is to move the origin only, unless hovering over a mesh, face, or surface. For these objects, the UCS aligns itself with the highlighted face, recognizing flipped faces or negative normals.
The circular grips, found along the X and Y axes, allow you to align the UCS based on a second pick point in space. To use this, activating a circular grip prompts you to pick “a point on the <chosen> axis”. The UCS icon rotates, awaiting your second pick point. Clicking in space or snapping to an object rotates the UCS to that location.
Also, if you want to use a specific angle rotation, type “<“, followed by the angle, then press ENTER. The UCS will lock to that rotation, still awaiting your second pick point. You can also activate the pop-up menu for the X and Y axes by hovering over one or the other.
Using this method, it is a bit clearer as to the behavior of the UCS axis grip, whether by choosing the axis direction, rotating around the Z axis or the unselected axis. So, if you are hovering over the X axis, you are given the choice to rotate about the Y axis.
Finally, you can reset to “World” by using the pop-up option at the origin.