I have recreated the linear falloff map that Viscorbel is talking about
HEREViscorbel has uploaded two OSL shaders that people can use in V-ray to correct the maps, but as far as I know, we can't use OSL in Corona.
I have uploaded a max 2013 scene with the custom falloff map and a Material Library.
Would be awesome if Corona got some kind of OSL support.
This is the OSL code that make linear falloff. Made by Wobi.
shader facing_ratio_linear (output color Col_Out = color(0.5))
{
float floatOut = acos (1.0 - (1 - (dot(normalize(N), normalize(I))* -1)))/(M_PI * 0.5);
Col_Out = color(floatOut , floatOut , floatOut );
}
Since we can't use the OSL, you have to plug the fixed falloff map into an Output map to adjust it.
Look into his eyes !
Enjoy.