Raven have coded into Quake 4 quite a few different 'surface types' than were present in Doom 3. 'Surface type' ensures the game plays the relevant sound, decal graphics and physical behavior depending on the 'type' of surfaces struck, hit or shot at. Open 'types.mtt' into Notepad or similar to see the full list of available types. 'types.mtt' can be found in the following location;
q4base\materials\types\types.mtt
