Weird marmoset normal map issue

SuperFranky

Was doing some test bakes today and noticed these weird shading artifacts on my normal map. Baked the map in XNormal using a cage.
http://i.imgur.com/fped21O.jpg

Anyone knows what's it all about? I don't remember seeing something like that before. I tried baking in .png and .tiff and it doesn't matter, the result is the same.

stevston89

The banding is caused by your normal map not marmoset. Make sure to bake at at least 16 bit. Try using targas instead.

SuperFranky

stevston89 wrote: »

The banding is caused by your normal map not marmoset. Make sure to bake at at least 16 bit. Try using targas instead.

Tried 16bit TIFF, no difference...

EarthQuake

Try PSD, 16 bit TIFFs only load as 8 bit (its a problem with the tiff loader). This is likely a bit-depth precision issue though.

SuperFranky

EarthQuake wrote: »

Try PSD, 16 bit TIFFs only load as 8 bit (its a problem with the tiff loader). This is likely a bit-depth precision issue though.

Converting map to psd solved the problem. Thanks. But is there any way to prevent this from happening?

EarthQuake

So the basic problem is a matter of bit depth, in other words how many colors an 8bit per channel image can display. This is generally a problem when you have very smooth surfaces, or your highpoly and your lowpoly geometry is very similar, so you get a very subtle result in the normal map. When that happens, the value range just isn't good enough to accurately represent it.

Depending on where you bake, the baker will handle this a little differently. Theres basically two ways to deal with it:
1. Dithering, which I believe Max does by default, dithering adds noise however
2. Using the closest values without dithering, which results in stair stepping artifacts, I think Maya and XN do this

If you have a 16 bit source, you can also re-save that as 8 bit from photoshop, which I think will dither the end result, so that should improve it without requiring 16 bit normal maps.

Though its sort of arguable if this sort of issue will be noticeable, especially after you texture the asset, add ao, throw it into a game engine with texture compression, view it at a reasonable viewing distance and all these things. It sort of depends on how much wear will be in the texture, if its intended to be a really clean style, these artifacts will be more visible, if its a worn style, its less of an issue generally.

stevston89

EarthQuake wrote: »

1. Dithering, which I believe Max does by default, dithering adds noise however

I always wondered why max baked noise in my normals now I know thanks EQ!

EarthQuake

stevston89 wrote: »

I always wondered why max baked noise in my normals now I know thanks EQ!

Yep, noise or banding, I'll take the noise, noise is really hard to see after the asset is textured.

stevston89

My issue was I would overlay my normals together when baking different elements out of max and then by the end I would realize I had a ton of noise all over. I have since stopped that. Now I know why I needed to stop. Yeah I will take minor noise over banding any day!

Joopson

EQ, can you bake 16 bit normal maps out of xNormal? I looked around, but couldn't figure it out.

almighty_gir

bake from xNormal in .tiff format, and they'll be 16 bit. but for best viewing in toolbag, resave them as .psd (simply open in photoshop and save as .psd. you can double check by clicking image > mode; to see if it's in 16bit format).

Joopson

Thanks, Lee. I'll have to try it out.

SuperFranky

Thanks, EarthQuake. That's very interesting and helpful to know.