default - hard ground with grass;
concrete - smooth concrete road, asphalt, concrete floors;
stone - paving stones, stones;
steel - metal surfaces, metal objects;
soil - ground, hard ground;
leaves - heaps of leaves, sheet layer;
dirt - soft ground cover;
roadSoil - rolled earth road;
roadmud - road covered in mud;
sand - loose sand on a dune, increased slip;
moon_sand - moon sand;
sand_slope - sand on the slopes;
quarrySand - deep sand in quarries;
roadSand - trampled sandy road;
snow - snow;
mud - deep mud;
ice - clear ice;
roadSnow - snowy road;
rocks - paving stones, stones;
rocksSlipper - wet rocky surfaces with increased slip;
gravel - gravel on a railway embankment or gravel path;
fabric - fabrics, tarpaulin, etc. types;
glass - glass surfaces;
wood - wood surfaces;
Based on physmat.blk
This doesn’t define texture! This defines physical material.