Can i create a normal map with just red and green channels so that blue cna be used for something else?

Can i create a normal map with just red and green channels so that blue cna be used for something else?

Yup,

Could even put a 2nd normal map into the B and A layers of an image.
Just dont set it as a normal map on import.

My problem is it doesnt look the same. For example if i use append and just make blue channel a solid blue… it looks different if i import the texture as normal map vs import as some sort of default map. This is with both using the blue as append… they still look different when plugged into the normal map slot.

I also dont want to use normal map compression because it increases teh file size so that saving a channel doesnt even help me where i could just add an alpha channel to the dif and have the same file size… with the default compression…

it might not look the same if you dont disable “SRGB”, and you might need a normalize/save normalize node after appending.

Well heres the thing about that. I have mentioned this in anotehr question… with no help on that… SRGB does nothing for me. At all… in any way i set it… wether its on mask or default… disabling or enabling srgb keeps the texture lookign exactly the same for me. Normal map method makes it look different… but i was looking into this issue when creating masks and nothing my greyscale values were lining up to what they are supposed to be in photoshop. Any info on this?

the SRGB <> RGB effect you see is very minimum, the way the engine handles it has a much more profound effect.
visually the value is only a few percent so its quite common you wont notice a difference at first.

The reason the normal map compression is different is because (afaik) it removed the blue channel information, and saves both the red and green channel across RGBA or something close to that.
(would need Erik/tim/Alexander/etc to explain it better than I can do).

well it doesnt help on the material, only thing that changes is when u switch the texture type from normal to default and vice versa… srgb doesnt change in color and it doesnt change the look of the texture when its plugged into the material … On top of that if im previewing a greyscale texture… i can use the eyedrop color picker tool… and grey values that are supposed to be around .25 end up being around .50… so its kinda a big difference. And the srgb does not change the value of the grey values at all… so yea…