Mirror Modifier Question

When I use the mirror modifier on a mesh and select a group of vertices, I’ll rotate or scale the vertices and the pivot point of the transformation is always the center of the real points. I’d like to rotate and scale around the center of the real and mirrored vertices. I know I can place the 3d cursor in the center and select the 3d cursor pivot point option to do that. However, when I need to translate the vertices a lot of times too, moving the cursor each time becomes time consuming and error prone. Is there an option that will automatically set the pivot point to the center of all selected vertices, real and mirrored?

You have to understand that when manipulating vertices, you are in edit mode, so the object’s origin has no effect. However, when using a mirror modifier you are using the object’s origin (the little orange dot) as the point from which to reflect. Your object has one origin from which all reflections are made, so the only way to reflect from different points is to use a mirror modifier with the ‘Mirror Object’ box set to an empty you place somewhere as the point to reflect from.

I’ve set an empty at the object center, but I don’t understand what to do next. I’ve tried all the pivot options and they still behave the same way.

Trying hitting Shift-S, and then selecting Cursor->Selection from the pop up menu. You can also change the position of the cursor with the View Properties mini window.