Env rotorwash emitter

This is an env_rotorwash_emitter available in Half-Life 2, Portal, and Alien Swarm. It creates a rotor wash effect, when a helicopter flies near the ground. The surface below must always be at most 1024 units away to be detected, and can either be solid ground, water or slime.

In code, it is represented by theCRotorWashEmitterclass, defined in therotorwash.cppfile.

Keyvalues

Altitude (altitude) ([todo internal name (i)]) <float>

Altitude the rotorwash will show up. Despite being present in the entity, it's not actually used for anything.