I converted a model to *.obj and imported in blender, but the surface normals are all weird.
Recalculating or flipping normals does not work.
Looking at the “vertex-per-face” normals I see that the normals seem aligned parallel with the surface!
One thing I’ve had succes with is sculpting the object with retopology on and zero strength. This fixes the normals, but the topology is messed up.
Setting vertex normals from faces makes the mesh look like smooth shading is turned on. Toggling between smooth and sharp returns (more or less) to the initial problem.
Wow, totally took care of it. I’ve never heard of ‘auto smooth’ before, but I must have turned it on by mistake.
Thank you very much! Blendering went from frustrating to fun again
Sure thing. I’ve never heard of or used it intentionally before either. I think the majority of what I know how to do in Blender started with just clicking random stuff anyways!
I had the same Problem with imported Geometry from another program. Thought I could share another solution for this if anyone stumbles across this thread and has the same problem but is intending to use Auto Smooth.
Go to Data Properties → Geometry Data and click “Clear Custom Split Normals Data”
This should fix the Shading even with Auto Smooth activated
Hi Jakob, and thanks very much for the answer.
In the five six years that have past since originally posting this I have encountered the problem again, and even created a second post where this was explained to me, so I’ll link that here.
Your solution is exactly right, or at least the best one I have found to this issue.
On a side note: I have only ever encountered this problem when importing game models (Farming Simulator, FS, Euro Truck Simulator, ETS, and the likes), but have not gotten further than that in understanding why these custom split normals are poorly imported.
