Posted by Bam

I suggest using Gonstruct when editing gmaps as you can edit the gmap as if it was a big level. (Which it kind of already is)

An example using a gmap I was working on, the yellow lines show each single level.

You can download Gonstruct here;
Link

Another thing you can do is use Nw2png to get a full image of your gmap. You can download it here; Link