hello
I’m importing from Blender to Unreal and some holes appear in the mesh as in the image below.
What is the correct configuration when exporting from Blender to Unreal via FBX?
the message that appears when importing fbx in unreal is this:
Cube_035 has some nearly zero tangents which can create some issues. (Tolerance of 1E-4)
Cube_035 has some nearly zero bi-normals which can create some issues. (Tolerance of 1E-4)
thanks
This also appears:
In this case the message that appears is:
No smoothing group information was found in this FBX scene. Please make sure to enable the ‘Export Smoothing Groups’ option in the FBX Exporter plug-in before exporting the file. Even for tools that don’t support smoothing groups, the FBX Exporter will generate appropriate smoothing data at export-time so that correct vertex normals can be inferred while importing.
Holes in the mesh are probably “Fliped Normals” in the original model. Some faces are inverted and the Unreal render engine don’t render theses faces. To check this before fixing the model in Blender you can enable “two sided shader” or “see faces from both sides” in the material properties inside Unreal Engine. I don’t remember the right name of this feature.
The second problem is probably something wrong with the texture, if the model have more than one UV channel you need put the texture in the right UV channel inside Unreal Engine. Some configurations Blender can not export in the FBX file and need by adjusted in the exporting processes.
One model that appers ok and perfect in Blender can have serious problems when exported.
Problem 1 - Fliped normals in faces (generate holes in the mesh inside game engines)
Problem 2 - Scale not 1 inside Blender. (you can verify this opening the side panel in Blender “press N”)
Problem 3 - More than one UV Channel
Problem 4 - Procedural materials (can not be exported)
Try solve one problem at time.
First remove all textures and try solve the “holes” problem.
After this verify the texture problem.
thank you for your attention
a few more questions:
Is there a correct configuration in: export FBX from blender?
And as for importing into Unreal, is there a correct configuration?
this message instruction: enable the ‘Export Smoothing Groups
Is it to use: auto smooth on the mesh in blender?
thank you again
The only configuration I change in the FBX when exporting is “Path Mode: Strip Path” (the textures need by in the same folder of the exported FBX file) Because in the past Blender versions the other options are broken.
In Unreal I don’t know, I have used Unreal Engine many years ago.
About the smothing groups I think you don’t need worry if your model don’t have any smooth face. (shade smooth in Blender) Many models are pure flat faces and don’t have any smooth face.
The best way for you understand all the trick is try create and import simple models like cubes or spheres.
1 - Create a sphere in blender choose a color and export the fbx
2 - Create a sphere and change the sphere to smooth (Shade Smooth) option and export the fbx
3 - Create a sphere and scale the sphere and export, see if the sphere have the right size. (in complex models scales different than 1 create a mess in the model exported) (In Blender select object, Ctrl + A and click Scale to make the scale 1)
4 - Create a sphere and aply a texture and export
5 - Create a sphere, select one face and press Alt + N and choose Flip and export (this probably will produce the hole problem)
When you get all the 5 models imported OK in Unreal Engine you will be able to solve the problems in your model and all the future models you find.
Good studies and good luck.
There are some possibilities mentioned here:
or in here:
hello
what you mean :
zero tangents
zero bi-normals
What appeared in the message during export?
thanks
