twippe

11-11-2017, 04:33 AM

hello,

in per fragment lightning, we use the normal that has been interpolated between vertices to compute light factor,

in per vertex lightning, we use the per vertex normal but we let the lightning factor interpolate instead of normal

i am noob at maths and i don't understand, why is there a difference ? in both cases the result depends on interpolated value, shouldn't the interpolated lightning factor be the same as the lightning factor we would calculate with an interpolated normal ?

thanks

in per fragment lightning, we use the normal that has been interpolated between vertices to compute light factor,

in per vertex lightning, we use the per vertex normal but we let the lightning factor interpolate instead of normal

i am noob at maths and i don't understand, why is there a difference ? in both cases the result depends on interpolated value, shouldn't the interpolated lightning factor be the same as the lightning factor we would calculate with an interpolated normal ?

thanks