What is wrong with my Normals?

(Distance880) #1

Here is my model

Mobis Built by distance880 on Sketchfab

I also posted a thread on Allegorithmic Forum, here


Here is a comparison between how a model renders in substance painter, vs how it renders in sketchfab

I use blender for exporting. I can't find a fix!

(Dark Minaz) #2

can you post all your maps?
seems like the metal map is kinda messing around
or the roughness

just one question though, why not just export directly from substance painter?
blender - obj - substance - export
seems better than reimporting it into blender.

(Distance880) #3

I made the package downloadable. You should be able to get the maps that way.

Mobis Built by distance880 on Sketchfab

I honestly feel like its a problem with the mesh. I created the meshes in blender, i suspect that's part of the problem, but cannot discover why.. Exporting from substance to sketchfab has been broken since 1.7ish. I'm not sure when it will be fixed.

(Dark Minaz) #4

got version 1.7.1 and it does work for me.

I downloaded the model, sadly the maps were not in the download, don't ask me why
but the normals were all set inverse.

Also you did triangulate everything, is there a specific reason for that?

also if you fix the side like the way in the image, it wouldn't have those lines.

for more id need the maps, since like i said, they were not in the download :smile:

(Dark Minaz) #5

p.s. thats where you can check it in maya, pretty sure blender got something like that too .. but i never used blender for more than a few minutes so i can't really tell you where exactly it is there

(Distance880) #6


The inverse normals is the problem. Because if you place the camera in the middle of the model, it appears to shade correctly from the inside out. In blender, the normals display to me as having the correct direction. How do i solve this?

I tried flipping the normals, what happens is they end up getting occluded, because all their backfaces are showing all of a sudden.


(Distance880) #7

This is from in blender, shows all the normals are facing outwards.

(Dark Minaz) #8

hmm in maya the obj was reversed.

vs if i open yours in substance (the file i downloaded)

(Distance880) #9

How is it possible, that blender is exporting the normals correctly, in the sense that the backfaces are not showing, yet at the same time, the normals are inverted while displaying the texture, such that the model looks like it has been turned inside out.

How can the faces point the correct way, but the textured faces, point the opposite way?

(Dark Minaz) #10

hmm somehow between your blender file and your obj that got exported it changed the normals
i did open it in blender and the same thing.

could you somehow send me the blender file so i could test out if it does the same when i try?

thats how it shows up in my blender when i import the obj

(Distance880) #11

here is the blender file.

I might have a clue. I think that the problem might stem from the fact that durring the modelling, rather than using a mirror modifier, I duplicated a mesh piece and scaled it -1. I think that after merging that part with the rest of the geometry, the mesh became broken some how.

Does a mesh contain two different sets of normals? A set that governs the direction of a backface, and another set that governs the direction of a textured face? That seems like what's happening, because the faces are NOT pointing inside within sketchfab, but the textured faces are pointing inside.

If that's not it, it could be the direction of the normals of the high poly mesh while baking, if the high poly mesh had inverted normal, that could recreate this problem, but the highpoly mesh when looked at in blend has correct facing normals...


(Dark Minaz) #12

somehow the blender file seems correct

when i hit export as obj
and then reimport it seems fine too. so i can't reproduce why it changed the normals.

There is only 1 normals setting :smile:
Sketchfab got a 2 side face rendering, that is why it seems kinda fine. hit it on single sided then you see the problem.

(Dark Minaz) #13

So summary, somehow it changed the normals (who knows why)
your blender file seems fine

Just hit export again, check the obj if it got normals correct this time, make a zip, upload it again.
celebrate ^^

(Distance880) #14

Thats what resulted in the sketchfab model from my first post, same export from the blender file i posted. I'm gonna have to shelf the project I guess.

(Dark Minaz) #15

just upload this

add the textures in sketchfab 3d viewer and it should work :smile:

(Distance880) #16

Mobis Built by distance880 on Sketchfab

same problem T_T

(Dark Minaz) #17

Test by dark-minaz on Sketchfab

added the 4 scaled down maps, but it seems to work exactly the way it should, normals are fine with single sided.

edit: added the 2k maps, and did it exactly like i wrote,
got your blender file, hit export obj, uploaded it, added the maps, and it seems to work.

edit2: can you post the normal map as itself? since i added the height map (the other didn't display) and maybe a screenshot how you added it? like i did?

(Distance880) #18

oops, i never uploaded the actual normal map, here you are.

(Distance880) #19

I'm uploading the substance painter project for you to peek at, thats the only place that it renders correctly.

You can see the difference.

(Dark Minaz) #20

it seems to be that the normal map itself is the problem
heigh map, no problems, but the normal seems to do the thing on the side.
But yeah, send me the substance painter project and ill look why it made so weird^^