>coworker rotates tangent space normalmap in photoshop

> picrelated
Grandpa? Anyway, based.

>>1009438
Explain how is this based

>>1009439
looks good to me

>>1009440

>>1009432 (OP)
You can rotate 90 degrees in an image editor as long as you move red to green and green to red channel. Any other angle transformation you need to do in a 3D editor and re-bake down.

>>1009452
you forgot about inverting (not every) RG channels

>>1009439
would still work heh

>>1009470
Yeah, I can never remember which way, it depends if it is green up or green down etc. I always check against a unrotated normal or with a light in the editor which way I need flip what.

>>1009492
Just see normalmap of hemisphere bump as reference. In the end it has to look this same after rotation

>>1009493
He rotates it 45 degrees, you can't do that as the red and green channel needs to be aligned with the tangent and the bi-tangent of the geometry you end up using it on.
But you can swap out the data between the tangent and the bi-tangent by swapping red and green channels.

This is useful if you have a normal map of a horizontal image element you want to have appear vertical.

If it looks like his map initially or not depends what directions your shader/software wants.
It'd be cool if we all had agreed on 'green-up red-right', but much like like 'Z-up' 'Y-up' we're not as lucky as to be living in such a world.

>>1009509
just have LUT for every possible rotation angle

>>1009492
OpenGL Y up
DirectX Y down

I always remember DirectX down since it starts with a D

Proprietary? Wild west lol

>>1009492
>>1009556
It's even easier to remember

In OpenGL positive green color points up, meaning whatever points up gonna look brighter, because green seems relatively bright to human eye
Generally in most cases light sources are above us (sun, lamp posts etc). So OpenGL normal maps gonna just look more natural to us because of these two factors

DirectX is made by Microsoft, that means they fucked up and did the opposite

Positive red always points right in both cases

>>1009439
>Rotates 45 degrees
Anon the tangent and bitangent need to be perpendicular from eachother
And the normal is perpendicular to both the tangent and bitangent.