ZDoom bridge over bridge

Hello, I just tried to make my first ZDoom bridge and I'm having some problems. I have a bridge going over a bridge but I wasn't sure how to have a sidedef on the upper bridge and the lower bridge. So I got this "genius" idea to stretch a linedef across the middle like this:
http://img4.imageshack.us/img4/4965/bridgeproblemow6.jpg
so I could put textures on both top and bottom bridges. Unfortunately, doing this left me with a lot of open sectors, and now I've tried all the nodebuilders but they all crash.

Here's the wad:
http://rapidshare.com/files/198551843/bridge_test.wad

Well, when you make a bridge with ZDoom, each section of the bridge does not have to have it's own sector. In fact, you're better off merging them together, unless you need the adjust floor/ceilings heights or light levels for those sectors. The only important part is the linedefs holding the textures. Usually they all belong to the same sector.

The thing you are trying to do is a bit difficult. Since a lindef can only hold one middle texture, there isn't really a clean way of superimposing two linedefs that use the same coordinates without having some sort of problems. ZDoom might be a bit lenient towards doing this, but it's a bad practice and makes it hard to view the map as well as maintain it. Try offsetting the X/Y location of the part where the bridge overlaps, so you don't have to place two textures on the same coordinates to begin with.

Strangest thing. I just opened it up again in Doom Builder and it gave me a message that it removed something (a sector or a sidedef, I wish I'd stopped to read it) and it works now. I still need keep your advice in mind for when this happens again, though. Thank you for the help.

EarthQuake said:

Well, when you make a bridge with ZDoom, each section of the bridge does not have to have it's own sector. In fact, you're better off merging them together, unless you need the adjust floor/ceilings heights or light levels for those sectors. The only important part is the linedefs holding the textures. Usually they all belong to the same sector.

I tried merging them and it took away the middle linedefs.

Hmm... try creating a self-referenced linedef within the sector and just copy and paste it, forming the bridge. I'm not familiar with DB, but I would honestly think there would be a function to merge selected sectors without monging up anything else. If anything, you can select all the lindefs and change all the sidedefs so they point to the same sector.

You're right, there is. Now I know the difference between "Join Sectors" and "Merge Sectors." Only problem is that since I covered up the linedefs on the lower bridge I can't get to that sector now, but at least now it works.

I have another question. When I do my x and y offsets like you said, do I just cross the linedefs or do I put vertices where they cross?

Yes, use vertexes where lines connect other lines. Making lines cross other lines without them being connected via vertexes is widely considered a poor mapping behavior, and it can also lead to other problems (iirc bad nodes, seg counts, etc). There are cases where you might be trying a special effect, where it's somewhat acceptable, but that's not the case here.