Thank u for respond Joojaa.
Do you mean lambert hypothesis do not takes into consideration spot light and directional light?
There is probabbly plenty of additional parameters i didnt includ in calculation such as spot light cone angle, spot and directional light orientation, faloff end etc.
My questions might look silly a bit, I'm a newby in low level shader programing.
I mean i try to find out in wich way L vector respods on a light position in the scene, and N vector as well.
For now, to make my scene as clear as possible, i just set Surface colour eqal to L and vector (in Houdiny/Vex) and move point light source along X Y and Z direction.
In render test below images with normal map derived with ambient occlusion in mental ray (maya) and Normals of houdiny
the result is totally different
normals derived with ambient occlusion shader in maya
normals in houdiny
I found some code in web
surface diffuse_()
{
normal Nn = normalize(N);
Oi = Os;
Ci = Oi * Cs * diffuse(Nn);
}
But i'm just trying to get some basic things that may open different posibilities.
Thanks