Normal map color space issue


(Kristaps R) #1

Hi All,

I have problem with sketchfabs color management. I have finished my model and animation, but i can't publish it till bug is fixed. Normal maps are being interpreted wrong.

Check it out here.

As you can see some of the moving parts get normal map inverted at some point in the movement.

I know its a color management problem, because on exactly the same polygons, at exactly the same time had same problem in Maya 2016 viewport 2.0(other renderers work fine). I spend crazy amount of time in looking for the cause, I deleted all mesh normals and recalculated them countless times and even remodeled some of the meshes, but for my surprise nothing worked. Then finally I started to google around and found that that's just a color management bug in viewport 2.0 and there is easy fix by changing color space to Linear.

Here are couple of links about the problem-

Problem in Sketchfab is that color space already is Linear. Switching to sRGB gives even worse result, so that's how I am 100% sure that's color management problem.

I have written this to support, but there hasn't been any response. Please don't ignore this. It should be easy thing to fix. Thanks!

Kind regards,

P.S. I did similar animation 2months ego and there wasn't this problem. I also noticed this problem month ago when I did other simpler animation, but it was not big deal on that one so I didn't look in to it that much.

(Mrchlblng) #2

@KristapsR we did not ignore your message!
Debugging the issue, it appears to not be a colorspace bug. When testing the "norm" for some pixels in your map, everything is normalized to 1 (if we had a colorspace issue, we would not). So it must be the case that your map is actually really in linear space (which is the default encoding we consider for normal maps).

We however have a bug in the tangents processing. We wrongly dropped some of your tangents and also recomputed them badly. A fix is on its way to fix both issues (and in your case of course, we will preserve your tangents).
As we are making big infrastructure changes I unfortunately cannot tell you when this will be live and will get back to you as soon as it is.

(Kristaps R) #3

Thanks for response! Glad to hear you are working on the fix and it is on its way :slight_smile: Good luck!

(Loomai) #4

I have been noticing this for the past weeks. Please let us know when this is resolved.

Thank you,


(Mrchlblng) #5

@KristapsR @loomai the fix is live!
You will have to reupload your model to fix the issue.

(Kristaps R) #6

It works! Thank you very much!


8 posts were split to a new topic: Morph issue