norm vector

[Trin]

Hi,

i want to determine the norm vector on a 3D graph, i have x y z position of a point on 3D coord, and now i want to determine either the Euler angle or a norm vector on that surface i need to know the direction of the point, i checked for the Euler angle and i realised that it need a cosine direction matrix, then its going to be somehow complicated to calculate the cosine direction matrix and then find the euler angle. so i just want to know if anyone has an idea or some hints to give me some idea of how i should processed.