   how to make footprint on ground?
  given a ground that consist of some triangles and a character, how to make footprint? I have some idea.  1. get position of foot of characcter that reach ground. 2.get the triangles that contain that foot. 3.get the average normal of these trangles and project foot to these trangles by the normal, so that the texture coordinate of these trangles could be got.then I can map footprint image . but it seem too complex. any better solution.   
  The usual way is to draw another triangle (or quad) on top of the ground, rather than modify the ground itself. You'll need to play with the Z-bias (I think that's what it is), or render without Z-tests to prevent z-fighting though.   ;  If it helps, what you're trying to is called a decal. It's not too hard to do, really.When it gets interesting is when the decal is placed on an edge, though (from a bullet or something). Good luck and happy coding.   ;Quote:Original post by Evil SteveThe usual way is to draw another triangle (or quad) on top of the ground, rather than modify the ground itself. You'll need to play with the Z-bias (I think that's what it is), or render without Z-tests to prevent z-fighting though.sorry I state unclearly.I do create another triangles according to project. but It seem to be complex. any link or help welcome.   