Always Proplems with inverted Normals


(Ndrakey) #1

I dont get it guys. I have a proper looking model in Autodesks Softimage. once I save it to Fbx and load it again in Softimage i see no issue (Softimage shows inverted faces marked as black). When i upload that FBX to sketchfab, I get issues. Almost everytime.

Isnt there a way inside Sketchfab to mark problematic areas and invert them without having to reupload and relight them again and again?


(Mrchlblng) #2

Hey @ndrakey,

when dealing with normals

  • we know we typically have issues for models having a "mirror modifier" where typically the result ends up having inverted normals
  • for all geometries that have a single null normal, we will end up recomputing all normals (for the corresponding geometries) because we don't know if this is intended or a "bug"; if you want an unlit part, you need to put small but non null normals. This is constraining but providing a nice UX to control normals (locally) is difficult so this might not be implemented in the near future (if at all on sketchfab).

Does this apply to your model?

Also, I'm not sure why you'd need to "relight" your model after a reupload? The reupload feature is supposed to re-apply your settings. If it doesn't, it could be a bug. Could you provide a bit more details about your workflow here?


(Krzysztof Zwolinski) #3

Did you reset history of the mesh? you know all operation like mirror modifiers etc? . Exporting and importing mesh into same program is not a test because every program insert into file a info that only same program can recognize. try import this fbx into Blender, 3ds or Maya and then you can see if the error is in the mesh or in Sketchfab.