background bump floor friction hard heavy industry iron machine mill plate sheet skid slide steel technology texture tool work army bumps decayed deck duty pattern regular scratched scratches shabby thick worn flaky paint rust rusty administration chaos crazy danger driver fun funny glimpse limit limits mistake one policemen roadsign roadsigns sleeping speed street way age aged ancient bark bole dents massive meadow nature old oldly power root Roots spring strong tree trees trunk brick bumpy calcite coarse Dirt earth granite lime Mineral quartz rock rough sand sandstone Soil stone wall bump map decay diamond plate diamondplate grunge industrial metal non-skid San Francisco sidewalk surface urban