FBX exporter having issues with face normals

Hi, I am exporting from Maya 2014 using the FBX exporter plugin and I am having an odd issue on importing it into UE4.

I export fine using the settings described in best practices documentation and everything looks fine in maya.
however on importing the model into UE4 using FBX face normals. the face normals all point UP in the asset preview of my skeleton.

It is not a reversed face normals issue, the normal angle on all faces points upwards resulting in all shadows from a light above the model to instead be on the reverse side.

the problem is most annoying due to using the calculate option also making bugged face normals with flat or incorrect angles.

anyone have any ideas? (assume I have googled this thing extensively)

To be clear, when you import your FBX, you’re using the “calculate normals” option instead of “import normals” or “import normals and tangents”?

Fenrix, what version of UE4 are you on? Is it a custom build from github or are you using the launcher?

stock UE4, 4.2.1 using the launcher.

I have tried it with both import and calculate.
Calculate caused some of the polygons to be hard edged with odd lighting where they shouldn’t have been. but in general the normal direction seemed to be fine other than the odd artifacts.

Import caused the strangely facing normals all over the model but smoothing and hard edges worked fine.

I fiddled with the normals, flipped and re flipped them and did everything I could think of, but no matter what I did, every export would come out messed up the same way.

Eventually I exported without rig to OBJ then re-imported to Maya and It looks like it may have fixed the problem. but I still do not know what caused it.
So whatever it was caused a conflict with both FBX exporting normals correctly and the normals calculation for UE4.
but hope that helps if anyone else spots the same issue.

Hi Fenrix -

This is an issue to do with some changes to computing bind pose and we are aware of this bug. Our Engineers are working on a fix, but I do not have any definitive timeline for you.

Thank You

Eric Ketchum

Thanks for the Info, will just work on other stuff for now. ended up re-building the model from scratch but haven’t imported it yet hopefully a fix occurs before I finish unwrapping and texturing it.

Thanks again.