Void Undo

If you've used the <V> key to delete a section of the mesh and accidentally selected the wrong faces, type <V><U> right away; this will unvoid what was just voided. There is only one level of undo.

Fill Undo

If you've accidentally filled one or more holes that you didn't want to, use <V><G>. Holes are filled with green marked faces, so you can easily make them holes again by deleting marked faces.

Save Regularly

Use the Tmp 1 to 5 buttons to quickly save the current mesh into temporary files. If you make a mistake that cant be fixed in other ways, you can then recover an earlier version of the mesh from one of the temp save files. Regular saving is a good idea anyway in case of a software or system crash.

Ghost Mesh