Am not sure wether lots of you use the AO shader as i’m the only one who noticed it’s buggy.
On many of my posts i talk about this:
posted on devs forum, and reported the bug.
Obviously devs are working on this but i guess the fix will be set up in blender 5.88 in 2035^^
Lemme remind you with the shit:
and the nodes setup:
By reading part of the second link of this post you can learn that this is due to a normal interpolation problem.
Okayyyyy normals are one of the elementary bricks of CG !!! cycles badly handling normal is just like a plane flying ‘sometimes’ ! LOL !
Well this is a bug beeing worked on but i need a solution NOW ( simply because the bug is known since dinosaurs era and also because i really need the AO node !!! )
This bug only appears when you turn on the smoothing on low poly object.
Solution won’t come from devs ( seems to be a kind of habit ) but from users finding a cheat by chance.
And here’s the cheat:
Pretty simple !
We need to use the true normal ( the non interpolated ( AKA flat ) face normal ) instead of the interpolated normal and feed the AO node normal input with this.
The bad part is that you cannot have smooth object. Only flat shaded.
I made a small nodes setup for switching from smooth to flat normals when output of AO node is pure black ( wich normally don’t happen ).
Here’s the nodes setup:
This unfortunately implies two AO calculations and is therefore slower but it dramatically reduces the visual defect though not eliminating it totally ( switching brutally between smooth and flat is a kind of abnormal behaviour ).
So here’s the final result: right before, left after
Hope you like it !
Happy blending !