Maya Beginner - Normal map horrors

Phillipsa

feels like i'm going around in circles with this issue and I'd REALLLY  appreciate some advice. I've baked my set of maps from my high poly model. everything seems to be ok until i apply the normal map (i'm basically following a video tutorial at this stage) when i apply the map my model goes SUPER contrasty like it's been shaded with a kid with a marker pen and each UV shell looks like the lighting is different on it which is creating horrific seams. It's not really looking like my sculpt at this point. My first attempt ended up 'pixelated' so I've redone the UV layout and spread it over multiple tiles baked 4k maps - it's still pretty pixellated. 

MichaelF

Its super hard to see whats going on, can you post the normal map?

throttlekitty

Check your bump2d node the normal map passes through (you DO have one, right?) and make sure it's set to tangent space normals; the default is bump.

Phillipsa

Thanks for your reply. Yep, like I say, I'm pretty much following video tutorials at this point. The super darkness is under default lighting and is a result of the normal map. I've found a workaround after reading about cross platform issues with normals. Basically my normals from mud box have weird edges (tangent twisting??) I ended up exporting my high res from mud box as OBJ and baking in maya which has produced correct looking normals without weird edges.

However, I can't figure out how to bake for multiple tiles- is there a way? I've worked around this by shift uVs around and doing individual bakes in 0-1 space and then using photoshop in difference mode to accurately align my map position. It works but seems long winded and eventually an error will happen. Is there a better way (I'm on a Mac so x-normal stays a dream for me ) if prefer not to touch my UV position.

ALSO I've notice when in photoshop on difference mode that there is an all over tonal different from the maps I produced in mud box to the maps I produced in maya suggesting a difference in tangents perhaps?

throttlekitty

Generally you want to be baking normal maps with the same tangent basis in sync that you're going to be rendering with. So if you're rendering in maya, do the normal bakes using maya. And yes, those differences are the result of different tangents.

I could have sworn Transfer Maps handled UDIM tiles, but google tells me otherwise, I'm not seeing any easy solutions, sorry.

Phillipsa

Thanks, and also damn. Seems a little dumb to have a function for multiple tiles and then not be able to bake them in one hit.  In that case I'm wondering what all these instructional videos did to get perfect normal maps straight from mud box? 

omar_0007

Not sure your issue is fixed or not, but when you load the normal map, there will be a color management box under the file upload box. Make sure its set to RAW.

 Also make sure you are using the right normal map colors, because openGL and DirectX have the green channels on normal maps flipped between each other.

Not sure what your issue is exactly but the above helped me. Its more than likely the color management thing though