As of version 3.0, a great amount of new features have been added, including item and player physics, using the Unity engine.
Item physics allow items to be rotated, rolled, and dropped instead of being teleported to the floor.
Ragdoll physics add physics to players and zombies once killed. The distance the corpse is moved depends on the weapon used. For example, if you use an axe to make a kill, the model with fly about 2-3 meters in front of you, whereas if you use a sniper rifle from 2 meters behind the target, the model may go flying 10-15 meters.