Notes: This tutorial assumes that you have a
desent understanding of WorldCraft and you have already read Make
a 1 way window and also have the example map(get it Here)
or have one way glass in your level.
Making the two “glass” bushes
breakable First, select the transparent brush of the “glass”
brushes and right click it in one of the 2d windows, select
properties then under Class choose func_breakable (in place of
func_wall) 
Attributes:
- Name it glass (Name)
- Set Material type to glass (Material type)
- Also make sure on the transparent brush the FX Amount
is around 150
- Repeat all but C on the “one way” brush, also make sure that
the FX Amount is 255.
You can now play the
map and you should be able to shoot out the windows, but they don’t
break as the same time. Leaving you with a transparent glass brush
or a brush that can only be seen from one side (the “one way”
brush), although one more shot will fix this, it is very confusing
shooting out glass and not being able to jump through the window
with out shooting what appears to be thin air! So lets fix this.
Breaking both glass brushes at the same
time Now, we need to “trigger” or break both of the brushes
when they are shot at. I am sure there are other ways to do this but
I found this way to be easy. All we have to do is put a brush
covered with the {blue texture one unit wider on each side of the
glass. Like so. 
The two pink brushes are the existing glass brushes and the white
one is our “trigger” breakable brush.
Properties of the “trigger” brush
Before you can do any thing, you need to make it in to a
func_breakable. Then, set your properties under Class.
- (Target on break)-What, when broke, will it trigger, or
in our case, break. Type in glass
- (Strength)-How strong the glass is, 80 takes 2-4 shots.
- (Material Type)- Set to Glass
- (FX Amount)- We want this to be completely invisible
so, Set to 255
- You can tweak other things as you wish (Gibs Direction,
etc.)
World
Expert's FGD