How to make trigger brushes not work unitl later in a map?

So let's say I put a trigger brush (the type that is activated by walking over it) on the map but don't want it to actually work until later in a map. How do I do that?

Example:

1.There are 2 rooms, room A and room B, and they are both connected to each other.

2. Room A has a trigger brush.

3. How do I make it so that the trigger brush in Room A doesn't trigger when the player walks over it unless he has already been in room B first?

You can have a trigger disable it. Use a trigger volume that disables the trigger when touched by the player then have something else enable your trigger later on.

In room B, I would do this: module > when entered > enable volume

where the volume is your trigger brush. Also, if you don't want a floating cylinder or rectangle in view on your map (the trigger) also do this:
In room B: module > when entered > make invisible > volume

this makes the volume invisible, but still active.

SCvoid said:

In room B, I would do this: module > when entered > enable volume

where the volume is your trigger brush. Also, if you don't want a floating cylinder or rectangle in view on your map (the trigger) also do this:
In room B: module > when entered > make invisible > volume

this makes the volume invisible, but still active.

You can actually set Visible on Start to false on the trigger so it starts invisible. The trigger will still work.

Map start -> disable volume - > set bolean Y to false.

On trigger, set Y to true.
When Y is changed -> enable volume.

hardcore_gamer said:

So let's say I put a trigger brush (the type that is activated by walking over it) on the map but don't want it to actually work until later in a map. How do I do that?

Example:

1.There are 2 rooms, room A and room B, and they are both connected to each other.

2. Room A has a trigger brush.

3. How do I make it so that the trigger brush in Room A doesn't trigger when the player walks over it unless he has already been in room B first?

In radiant any trigger volume has an option "trigger_first", set it on and target another trigger to it, wich will trigger it to be active. Isn't there something like this in SM?