Throughout Half-Life 2, sounds made from your gun, enemy communication, and pretty much all sounds were affected by the enviornment. For instance, if you shot a gun in an enclosed concrete hallway, a muted echo of the bulled could be heard - If you did the same in a large field, either an echo after a period of time, or no echo at all coulde be heard. My question, you ask? How is this done and/or controlled? I figured this was auto-calculated by the engine based on the brushes surounding the area, but no matter what design of map I make, the guns/enemies all sound alike.
Thanks