Following video tutorial is a part 2 series. I go through all the steps required to create a function-able elevator in Left 4 Dead.
We will set up a button sequence to have our elevator travel to 2nd floor and back down on button press.
Part 2 of the tutorial can be found here.
Creating an Elevator:
Create an elevator out of brushes. Select all the brushes and turn them into an entity.
You want to pay attention to the elevator's properties.
If your elevator is going up and down, then pay attention to the 3rd number in the sequence.
Top Floor Position / Bottom Floor Position
Make you know where you elevator is on bottom and on top.
Manually move your elevator to the top or to the bottom to find out the values.
Once you know that number, change it in the elevator properties.
Place 2 entities.
One on the top of the floor, one on the bottom.
Name top one: top
Name bottom one: bottom
Insert logic_relay entity
Create a second logic_relay entity
Create a button.
Use an entity, prop_dynamic for the visual representation of a button.
Parent the prop_dynamic to the elevator.
Use brush tool and create a brush with invisible texture applied on the brush.
Brush will be tied into an entity func_button. We won't see it in game, but it will act as a button.
Duplicate the same brush for the bottom
Control+T on both of the brushes and turn them into func_button.
Under flags set both buttons to Don't Move and Use Activates
Parent both func_buttons to the elevator