The normal vector of a surface is the cross product of the respective vectors. The first vector is (v1x-v0x,v1y-v0y,v1z-v0z) and the second vector (v1x-v0x,v1y-v0y,v1z-v0z) where v0x is the triangles first vertixs x coordinate, v1x if the second vertexs x coordinate and so on. Then build a 3x3 matrix with the unit vectors i,j and k in the first row, the first vector in the second and the second vector in the last, solve the matrix and you have the surface normal (aka. the cross product) where the i represents your x magnitude, j your y magnitude and k your z magnitude. Alternatively there might be a SurfaceNormal command or something. Usually you would use the PickedNX or CollisionNX commands tho', but it all depends on what you're trying to acheive. In your example a simple LinePick from above and then using AlignToVector on the PickedNX,NY and NZ should do the trick. Don't forget to set your EntityPickMode.