How to guess if a normal map needs gamma or not

[rezvan23]

Ah, I think both of them are true, right? Green-Top and Red-Left is actually rotated 180 degrees of Green-Bottom and Red-Right

[piotrus3333]

I see. So as Vizioen said above, RED needs to be illuminated from the right and GREEN needs to be illuminated from the bottom. Am I understand correctly?

that would be “VRay format” of normal map, yes.
I consider “flip green” pretty much a default as this is much more common.

[S_K_I]

I see. So as Vizioen said above, RED needs to be illuminated from the right and GREEN needs to be illuminated from the bottom. Am I understand correctly?

Can anyone else comment to confirm this is the correct alignment? Red = Right and Green = Bottom?

I've been having this very same issue when testing the normals and I can't figure out which is the correct way so need confirmation on this.

[DCHA34]

ok so just a bit confused, ive only ever had to flip the green channel depending on if its opengl or directx, i dont think anyone flips the red. Also im pretty sure every normal map ive seen, the red is as if illuminated from the right.

I totally agree with this observation.
What is it really like?
Could we have an answer from Chaos?

[DCHA34]

Still no answer from Chaos.
Are we sure they read this topic?

[S_K_I]

Bumping for an answer on the red and green channels and which direction they should be facing.

[DCHA34]

I totally agree with you.

I think there are many of us who want to know this information.

But I don't think this section should be "under surveillance" by Chaos because we have been waiting for months for the answer.

[seandunderdale]

maybe start a new thread in another forum if this isn't getting eyes on it.

[olly]

Or email support@chaosgroup.com, to start a support ticket, and refer them to a thread.