   car tyre marks
  I just wanna know how pro developers go about putting car tyre marks.. e.g. when the car skids or it moves over a sandy patch or etc.. specially when the road/terrain is bumpy or a lil hilly   
  I dont know how "pro developers" do it, but I know several ways.First you can use decals, or if the ground is bumpy, use grid decals and move the vertices to conform to the terrain. Or you can use some kind of texture bombing or splatting, or even projective textureing.   ;  anymore ideas.. actually i have some of my own ideas.. but just wanna know how pro devs go about this issue   ;  Every frame that you resolve collision between your tyre (tire?) and the ground, store that point ( p0 ) if you are in a skid state.Next frame, when you test your tyre, this becomes p1.Use some measurement to determine how often to sample the point. Every frame might be good, or maybe if the magnitude of the difference between p1 and p0 is above a threshold sample the point.Draw lines from p0 to p1, p1 to p2, etc. You may have add to the z component a bit to avoid z fighting. We create lines of specific tyre thickness and tile the texture along it.If you ground doesn't match your physics geometry properly then I don't know what else to do unless you want to actually decal across the terrain yourself. We've always made your physics geometry and road-deck geometry match.- S