Blender to gltf -> fliped normals only in some (mirrored) meshes

[vitezslav]

Hello! I am facing such a problem. I exported a scene to .glb from blender and there are fliped normals only in some meshes (just the ones I mirrored in blender in object mode with “ctrl+m”). In blender viewport I see normals being right way, but in my “game” are opposite. Of course I can simply flip them to be wrong in blender and correct in game, but it can become confusing with bigger scene and more objects.
Has anyone else encountered this problem?
Thank you, have a nice day!![wrong normals|648x500]

(upload://yG9WCzZqyG2bh3HLJiMadpXHAbi.jpeg)

http://www.vitezslavplavec.com/another_world/another_world.html

[JCPalmer]

On tablet, short answer. flip your normals. Since in the 3D viewport back face culling is not done. They then look OK there, but are backwards once exported.

I use the .Babylon exporter & occasionally get it as well.

[vitezslav]

Ok, I understand, thank you)

[Vinc3r]

In Blender, when doing a mirror action, you basically just invert scaling values

So to “clean” the mesh, you have to apply values:

Once done, you can see that normals are inverted, so just go to edit mode > select all > Alt +N > F

[Heathcote]

Did you have a fix on this issue? I am facing the same issue last time. But no response from anyone.

[Vinc3r]

My post above tells you how to fix this.