Can anyone assist me in getting a part of a mirrored object to move without overlapping into itself?
In 3DSMax it consisted of changing the view from global to local and then the whole thing moved instead of overlapping. In Blender I've tried all the local views and they aren't working.
Below is what is happening -
A mesh data is fed through the modifier stack from top to bottom, and what's accessible through Edit mode is only the original data, not the result of the modifier stack. Modification of a modifier's output is only possible by applying it first, or through another modifier lower down the stack.
In your example, vertices generated on-the-fly by Mirror modifier can't be moved past the modifier's mirror axis, even if Clipping is disabled and the modifier is applied to editing cage. That's because it's not in the original mesh data, and its position is not stored independently but calculated by the modifier:
Modifying those vertices manually is possible after applying it, because those new vertices are now available in the original mesh data. Other modifier can also modify them if placed below the Mirror modifier, for example an Armature modifier (note the modifier stack):
or a Lattice modifier:
Just move it in Object Mode (Tab to toggle)
The Mirror modifier works according to the Origin (aka pivot) of the object - that is the orange dot that shows on selected objects - unless you specifically tell it to use a different location (by selecting something for the Mirror Object)
In Edit mode, you are manipulating the vertices/edges/faces of the mesh itself, not the object as a whole, so when you select everything in edit mode and move it about, the origin stays where it was and thus the mirrored mesh goes out of alignment:
So instead, Tab out of edit mode and move the entire object.
If you wish to reposition the origin of the object without moving the mesh, you can use Shift+S to place the 3D Cursor at some position, and then Ctrl+Shift+Alt+C in object mode to move the origin to the 3D cursor.
You may notice the Origin to Selected button in that screenshot, this is not a built-in function of blender but rather a function in my own addon that simply performs these two functions in one go since I do this frequently. If anyone is interested, I could upload this addon.
That's because you're moving that piece through the mirror plane (the YZ Plane, or X axis, in your case).
The mirror plane is defined relative to your object coordinates. You can change the plane by using the Mirror Object setting of the Mirror modifier.
If you're trying to have two different mirror axes in a single mesh, or to selectively mirror only certain vertices, I don't believe that's possible at this time.
I'm not quite familiar with 3DSMax, but I guess you may be looking for the result when toggling Clipping in the Mirror modifier panel, suppose you got one.
Otherwise, it's not possible to do "un-mirror" transformation while working with Mirror modifier. You can either apply the mirror modifier before moving, or add additional modifiers below it in the Modifier stack to make further modifications, such as Lattice.
