Fredrik Johansson has updated the Frad Design pages with a new editing trick he has just discovered.
I finally figured out how to create a perfect double sky. That is, one that does not cause HOM, does not block the player or projectiles, one that does not make any ugly streaks high up there. I am shocked that it took me a year to figure out this incredibly simple solution.
Here is a screenshot of the effect. The news post continues with some thoughts about Vrack 3 and its insane number of linedefs, and finally ends up with a scary and evil laugh and the promise to make \"the most extreme DOOM2 map ever\".