Terrain Collision!

sure

 y = terrainy( terrain, entityx(player), entityz(player))
 tformpoint 0,0,steplength, player, 0
 dy = terrainy( terrain, entityx(player)+tformedx(), entityz(player)+tformedz() ) ; height after the next step
 if abs(y-dy) > maxStepHeight
  ; do not allow the step
 endif

but I just realized that this is in the totally wrong board, could someone move it to b3d?