Perspective Correct Interpolation

 

z is the z component of a vector in eye space

 

perspective correct interpolation will linearly interpolate attribute s1, s2, s3

 

using

 

s1/z1, s2/z2, s3/z3

 

then divide the result by

 

1/z

 

where z is the linearly interpolated result of

 

1/z1, 1/z2, 1/z3