UE4 flips my model "inside out" (normals) while importing a fbx and won't let me "fix" it

For few hours now im trying to import a puppy model that i made in blender just to see it as a static mesh inside UE4. The problem is, that whenever i do so, the model is flipped inside out in UE4 even tho my normals are completely correct inside blender(pics). I thought i had some import option ticked, that inverts them, but i checked, unchecked each and single option inside an import window, and that did’nt change anything at all.
I’m just starting with ue4 and blender, but come on… I fliped the normals in blender so they faced inward just to see if this helps, and yes - model inside ue4 was then the way it should be, but shading was messed up. , and model itself was darker. How do i fix it?

Sometimes it is not the model causing the issue. The import might very well have worked with correct normals. But the material might be setup incorrectly. You want to double click the mesh to open it in the specific asset then select Show -> Normals for static meshes or Character -> Advanced -> Normals for skeletal meshes. That’ll tell you if the import worked correctly.

Then you just need to fix the material. My suggestion is that you try to create materials in UE4 itself and not rely on transfer from Blender fbx.

the applied material is WorldGridMaterial so that has nothing do to with it :rolleyes:

I did not work with blender, but some search results that are worth checking:

" My guess would be that your object has negative scale in Object mode. As .obj does not store object transforms, the scale is applied on export and so causes the normals have negative direction as well.
To fix this, in Object mode hit Ctrl + A > Scale, then do the operation described in answer you already found (in Edit mode hit Ctrl + N) and then re-export.

"

5 Likes

The scale was indeed negative and this caused an issue. Thank You and everyone else here for replies!

You are indeed a legend, thank you so much mate

Negative scale was my issue as well. Thx @ Nawrot!

In blender
You can also ALT-N & select flip.
Then re import

The only few times this happens in blender, is usually when you mirrored an axis.

Scale Y -1

And you forgot to “apply all transforms”.

Soon as you do apply transforms, even in blender, your normals will flip.
That’s how the object is usually imported into the engine.
Probably because of the “experimental” apply all checkmark, but unchecking that doesn’t guarantee the normals get fixed when you export.

Its really a blender issue in the end… they should add a modal saying “this mesh has non applied transforms, would you like to apply them” any time you export…
Which actually, thats something I may do on my curves plugin now that I mentioned it…

1 Like