   Given a Vector3, how can I find the perpendicular Vector3
  Given a Vector3, how can I find the perpendicular Vector3 on the XZ plane.For example, if you have a vector goign forward (0,0,1), the perpendicular vector on the XZ plane would be the one going right (1,0,0) or left (-1,0,0).Just wondering - how would I find this? Thanks,-TPG   
  cross-productR.x = U.y * F.z - F.y * U.zR.y = U.z * F.x - F.z * U.xR.z = U.x * F.y - F.x * U.y