This applies the same fix as for Eevee, i.e. the scaled normals
are applied before transforming from tangent space to world space.
Previous behavior is retained for all normals which aren't in tangent
space.
Previously the normal strength was modified in world space instead of
tangent space. The node returns directly after, but keeps the old
method in order to not break ex. object space normals strength
Previously the normal strength calculations were linearly extrapolating
the supplied normal map respect to different scaling in the xy resp.
z-axis. This new method takes this into account and applies it in the
correct way.
The calculations are identical to the ones presented in #109679 but
translated into glsl.
Please see #109679 for more information and background.
Brecht Van Lommel
Kaspian Jakobsson