Dark shading on uploaded model

Support
#1

With a recent upload, a section of my upload has shown up darker than the rest. It is an old truck and it is the rear fenders (See photos attached.) I have tried a few things like flipping the normals, checking the normal direction etc, but have had no luck. If you have any suggestions of what to try, I would greatly appreciate it. Everything seemed fine when exporting from Blender and into substance painter, but am now having this issue in sketchfab, so I am not sure what is causing it. Any help would be appreciated!

Truck_issue_1
Truck_issue_11301×741 51.7 KB

Truck_Issue_2
Truck_Issue_21128×740 149 KB

#2

substance_truck_fender
substance_truck_fender1054×670 253 KB

blender_normals
blender_normals1085×739 43.8 KB

Here are photos of it in both Blender and Substance, where things worked fine.

#3

My first guess would be to check you don’t have any vertex colours being uploaded, since I know Substance uses these for various masking functions.

To do this on Sketchfab, go to the ‘Scene’ tab and disable them there.

#4

Thank you for your reply! I don’t believe that any vertex colors loaded in, as I don’t see the option to disable them under the scene tab. However, upon playing with some of the processing filters, the subsurface cleared up the dark areas, to a normal appearance. I have rolled with this setup for now, but perhaps this is a lead to what may be causing the issue?

#5

perhaps its related to custom split normals which you would need to clear in blender