How to create symmetry?

Mar 23, 2010
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1,696
So, I'm on the middle point of my map, and I need to create symmetry. I tried doing it manually, and it was just awful.

Should I just create half of it, and then SHIFT+move/rotate it?

Thanks.
 
Mar 23, 2010
1,872
1,696
something is not working. ;) I get some of the map matching up perfectly, and other parts not matching at all.

EDIT: I got it. Just had to do a couple of things.