Surfaceparms

The default surface type is stone. For all other surface types you will have to create shaders so that the impact sound/mark is correct for the material. Current surface types are as follows:

stone (default)	puff of smoke, heavy boot on concrete surface sound
glass	usually on glass func_explosive entities
grass steps	brown bullet spray, springy footsteps
gravel steps	brown bullet spray, crunchy footsteps
metal steps	puff of smoke, clanky footsteps, metallic ricochet
roofs steps	clanky footsteps
snow steps	white bullet spray, crunchy footsteps
wood steps	puff of smoke, hollow steps

Landmines

A landmine is a small anti-personnel device used to blow up members of the opposing team. In order to allow players to place a landmine, there must be a floor surface with a surfaceparm type of landmine. This is a special surface type which can be used either on its own or with additional surfaceparm types.

As a rule only add the landmine surfaceparm to 'soft' materials like sand, earth etc. In the Enemy Territory game all wood / concrete / stone surfaces were excluded from landmine use.