ZombieMod takes a unique approach on the Zombie Apocalypse by putting it in the perspective of a military commander, not a survivor. Since it is 2 years after the first infections, resistance on the east coast is organized, resulting in battles rather than small groups fighting for survival.
Ever notice how when it's really cold we can see our breath? When we head outside on a cold day, water molecules in our breath lose the energy that keeps them moving. Instead of bouncing around, they crowd up next to each other. And as they slow down, the molecules change from a gas state to denser liquid and solid states — the visible cloud of tiny particles of water and ice that you see when you exhale.
Anyways, since ZombieMod takes place in the late fall/winter, it would seem unnatural for this phenomenon to not occur. So, we implemented it. Here is a demonstration of the fx, which is still WIP. From 0:00-0:09 is the normal breathing cycle. From 0:09-0:15 is the running cycle. From 0:15-0:21 is the exhausted cycle and normal cycle, and the soldiers gets a breathing apparatus, which removes the breathing FX. Enjoy!