Ceilings coming down.

Hello good DOOMsters.

I have made a map in Slade level editor (probably not the best choice). It runs fine and well until I add monsters. The ceilings sometimes come down randomly. As far as I have tested it I haven't had it happen yet in sectors which have no doors next to them.
I'm not sure anymore what it's related to; the doors / sectors or the monsters themselves.
If anyone can take a look at my map i would be very happy. The zip in this link has the map twice. Once without monsters and one with monsters.

http://www.megaupload.com/?d=GU7DIZXT

Many thanks from Doki Doki.

When you create doors, the linedefs with the door specials must face outward, that is the first sidedef must be the one you press use on in-game. Some of your doors appear correct, like the one toward the eastern side of the map, while many of the others are backwards. It's just a matter of flipping the linedef's direction as well as the both sidedefs for each door.

The reason irrelevant sectors start moving up and down, is because on D1/DR (or P1/PR) linedef types, the sector on the back side of the line is what is affected. This is done so you don't have to tag these sorts of linedefs to sectors.

Doom Builder should have a command that will flip all selected linedefs, so fixing it should be relatively simple. Remember, you want to flip both the linedef and sidedefs for each linedef so your sector references don't get messed up.

Ah, I used the linedefs like that to make it so that a door can only be opened from one side or only with a button.
Seems I did it then the wrong way. I shall look into how to do it right.

Thanks for the info.

If you want a door to only be openable from one side, don't assign a linedef action to one of the sides. For switches that open doors though, you'll have to use an "SR" or "S1" type action and assign a tag to that linedef and the sector to be affected.

Ah, i know now how to do it. I selected previously the whole sector and clicked create door (in Slade) which then indeed makes a 2 side openable door which i often didn't want. Switches and all I know basically how they work but made the same error there.

Many thanks.

To make switch-operated doors you need to use the "remote door" line types on the switch. Then give the switch a tag number and give the door sector (not the two lines!) the same tag. The lines of the door themselves should have no line-type on them.

Note that if it's a door that opens and closes it also needs a switch on the other side so you can get out of the room!