UE4 Quick Tip #10: Fix Import Mesh Error "Degenerate Tangent, Incorrect Shading, Zero Bi-Normals"

Share on facebook
Share on twitter

UE4 Quick Tip #10: Fix Import Mesh Error "Degenerate Tangent, Incorrect Shading, Zero Bi-Normals"

14 211 views | 28 Jul. 2019
14 211 views | 28 Jul. 2019

FREE PDF Download "UE4 Beginner's Guide": https://www.worldofleveldesign.com/store/free-guides/ue4-beginners-crash-course-guide.php


Full UE4 Quick Tip Playlist: https://www.youtube.com/playlist?list=PL_c7yiTIRI8rPQfsNytgjgJh-bssWUczX

If you receive the following two errors on Static Mesh import:

- static_mesh_name has degenerate tangent bases which will result in incorrect shading. MikkTSpace relies on tangent bases and may result in mesh corruption, consider disabling this option.

- static_mesh_name has some nearly zero bi-normals/normals/tangents which can create some issues. (Tolerance of 1E-4)


Learn UE4 as an Absolute Beginner Without Any Prior Knowledge or Experience of the Game Engine with "UE4 Fundamentals Vol.1" Tutorial Course: https://www.worldofleveldesign.com/store/ue4-fundamentals.php


WoLD UE4 Tutorials List:



Follow World of Level Design

WoLD on Twitter: http://www.twitter.com/GameLevelDesign

WoLD on Facebook: http://www.facebook.com/worldofleveldesign

WoLD on Instagram: http://www.instagram.com/worldofleveldesign/


Thank you. This was great!


Does this apply when you export as Datasmith ?

Kell H

thank you - this was driving me CRAZY!!

Fire Noodle

What if you doubled up on your UV's intentionally? Say for foliage?

Ty_ teynium

I barely see tutorial videos that explain fixing errors! Nice! Can you do one of these for skeletal meshes?

Asking Anime

nobody seems to be covering degenerate meshes where the engine wont even let you import the mesh into it


I am so glad I saw this video. So tired of seeing this. Thanks so much!


bro u help me but i get again problem after this...now i have a problem going through construction please answer bro help me!
because i am making first person game and now i can go trough construction but i dont want that.
pls help <3 sorry for bad english

Commander Graham

This isnt a blender tutorial so its trash
why is the import materials/textures greyed out but checked by default? i cant see the import materials tab i only see the import textures and blender models have autogenerated textures besides things like emissions for some reason.


What if your UVWs are totaly fine but the "nearly zero bi-normals" Error still pops up?

I checked nearly everything, unwrapped the model several times without any overlapping UVWs, cleaned the history, cleaned /reworked the mesh, even xView in 3ds max has nothing to complain. But still the same Error. Thats exhausting me.


it's been 4 years since I started using ue4 and I never knew the error was coming from the fact that I put no uv on my mesh... I feel quite stupid now.
Anyway, thanks for this tips, by reading "degenerate tangent", I always thought it was my verts which were badly made by me while modelling, or that the normals weren't good ect...
Now that I know, I wonder : most of my models use some basic colors on their material ( so a diffuse, which is obviously seamless ), is this error a problem for these meshes ? because as I don't use any texture, I feel like I don't need a uv map.

Ben Askren

Очень чисто по-английски говоришь. Ты где-то в Штатах что-ли работаешь?