Normal map shading error based on camera angle

m00k

Hi people,

I'm having some issues with my normal map. My model shades correctly until I apply my normal map. The texture itself looks fine to me but I don't have alot of experience with baking.

Some info on the model:

• My high poly was basically the same as my low poly model but I used modo's rounded edge shader.
• All edges are set to soft shading except for uv boundry edges which are hard.
• Using MIK Tangent basis (I don't know exactly what this does)

Without normal map

With the normal map applied

Normal map applied as a diffuse

UV unwrap

Thanks in advance

Kanni3d

Could be a few different things, I'd imagine the first thing to check would be for any inverted faces on your mesh, and any inverted/backwards UVs in your unwrap. Doing procedures like triangulating your mesh before baking also mitigates some issues too. One thing however, is that your UV unwrap/layout is really rough. This wouldn't attribute to the problem with the dark faces and stuff, but definitely if you were to straighten out those islands, especially the longer and larger ones, that'll help with jagged edges on your normal map!

Feel free to PM me or upload your mesh for me or others to troubleshoot much easier to troubleshoot that way

ZacD

Also looks like there could be an sRGB versus linear color space issue, that normal map is really light in color. I don't know enough about Modo. 

m00k

ZacD said:

Also looks like there could be an sRGB versus linear color space issue, that normal map is really light in color. I don't know enough about Modo. 

Hmm I'm going to have to read up on some terminology and normal map stuff in general. I don't think thats the problem though the normal map is set to linear.

Kanni3d said:

Could be a few different things, I'd imagine the first thing to check would be for any inverted faces on your mesh, and any inverted/backwards UVs in your unwrap. Doing procedures like triangulating your mesh before baking also mitigates some issues too. One thing however, is that your UV unwrap/layout is really rough. This wouldn't attribute to the problem with the dark faces and stuff, but definitely if you were to straighten out those islands, especially the longer and larger ones, that'll help with jagged edges on your normal map!

Feel free to PM me or upload your mesh for me or others to troubleshoot much easier to troubleshoot that way

• The normals are fine
• I did have some flipped UVs but it doesn't seem to affect my shading
• Do you mean triangulating my high poly or my low poly or both
• That makes sense, I'll think if that on my next model thanks for the tip!
• I might take you up on that thanks for the offer

Thanks for your replies guys!
I'm going to go fiddle around some more if i find a solution I'll update this thread.

Kanni3d

@m00k I meant triangulate your low poly before baking, if that doesn't solve much, I wouldn't mind taking a look cheers

m00k

For anyone else with this problem I fixed it by:

• normalizing the normal map with GIMP's normal map plugin (photoshop has a similar plugin). 
• Flipping my inverted UV islands.
• Setting the colorspace to sRGB

gimp normal map plugin: https://code.google.com/archive/p/gimp-normalmap/
nvidia texture tools for photoshop: https://developer.nvidia.com/nvidia-texture-tools-adobe-photoshop


gimps normal map plugin

If someone stumbles across this and doesn't know what this means. Read up on normal maps on polycount's wiki

Cheers!

Mark Dygert

Once you figure out the normal map issue, you need to address that UV layout. Straighten out those long flat pieces, they will pack so much better and the texture will be built with solid strips of pixels instead of jagged aliased, diagonal lines. It should give you enough space to give some of the smaller parts more space so they will have more than a pixel to work with. Right now I don't think an 8k map would be enough to fill in those tiny details. You could get that entire tank at a high textel density at 2k probably 1k if you really needed to.

poopipe

You should fix this at source.  Normal maps should be stored linear or you end up with crushed values.  yours is stored as sRGB - that will probably be down to the bake output settings.

Also I agree about the UVs

m00k

Thanks for the tips guys I'll keep it in mind for my next model!