Notice: This file is temporary for now.  It is to give everyone the basic
information that I am currently aware of on this subject.  I wrote DMapEdit,
but I really haven't created any maps for Doom for the most part.  I know
basically how to create many standard structures in theory, however, and I
will explain them here.  When I learn more about the subject and can expand
on the information within here, I will write a new file to replace this one.

Bridges:
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What is a bridge?

A bridge is basically a pathway that is open on either side.  By open, I mean
that if you walk off one of the two sides, you will fall down to a lower
area.  Typically, there is slime or lava or the like in such areas, but it
doesn't have to be so.  Usually I won't call it a bridge unless the drop is
at least 24 units, making it impossible to climb back up onto the bridge
again if you do walk off.

Bridges are rather simple to create.  You simple have the bridge section one
sector, and two sectors on either side of the bridge with lower floor
heights.  That's all that's required.  At least for a static bridge.  Anyone
wanting to know about bridges however are usually interested in bridges that
either drop down into a pit or raise out of a pit.  These I call non-static
bridges.  To create these, you must first create a static bridge.  If it is
going to raise out of a pit or something, you will want to make the bridge's
floor height what it will start at, usually the same height as the pit's
bottom.  Even though the floor heights are the same, you still need to have
a seperate 'bridge' sector.  Once this is done, you need to set up a switch
or line somewhere that will activate the bridge, either raise or lower.  Tie
that line to the bridge sector by giving both the sector and the line the
same trigger id number, and you should be set to go.

The linetypes you will want to use for this will be the 'raise floor' or
'lower floor' types.  There are many types for each, and you will need to
choose the one that fits your exact needs.  A word of warning, however.  I
don't recommend using the reusable types usually, unless you want your
bridge to move between multiple heights, instead of just 2.