L4D2 Level Design/Instructor Hints
While you should strive to make player goals clear through the use of lighting and map design, you will often find that it is helpful to provide progression information on screen. This is particularly true if you require a custom activity or have an unexpected event that you'd like to inform your players about. The convention in Left 4 Dead is to use an instructor hint, and Left 4 Dead 2 allows you to create your own.
Creating a custom hint
Additionally, the hint will also need a 3D location in your map to appear and to control visibility. We can do this by creating a client-side entity to point to. The easiest way to accomplish this is to place a named
info_target entity and enabling the "transmit to client" (respect PVS) flag. This can be found under the Flags tab of the properties dialog when the info_target is selected. Once you assign the
info_target as the Target Entity of the
env_instructor_hint, you should see your hint in game.