Johan K said:
Dom 3 makes use of the alpha channel in map images. So you can make transparent corners or a donut world with a real hole in the middle if you want to.
Nice to know. I would like to create a high quality map for my total conversion mod someday, and I will definitely use this.
"Training is principally an act of faith. The athlete must believe in its efficacy: he must believe that through training he will become fitter and stronger, that by constant repetition of the same movements he will become more skillful."