Mesh Lighting Issue (Solved)

HarlequinWerewolf

Hi Polycount! For my final project this year I wanted to try a low poly style film in Unity and it was all going fine until today. I pulled the finalised model into Unity and applied the materials but this time the left eye is having some issues. It's a darker than the right despite having the same material and if I rotate the directional light away from the model, the eye geometry lights up...

However, the model in Maya looks fine...

And it's more obvious if I take off the emission...

Any help on how to fix this would be super appreciated. I'm still pretty new to Unity and I'm not even sure what's causing the problems...

Eric Chadwick

Looks like the eye model was mirrored. This is usually done in the 3d modeling app by adding a negative scale, which when exported to a game engine can cause lighting problems. Try removing the history and re-exporting.

HarlequinWerewolf

Thanks Eric, but I had already deleted all my history before exporting to an FBX

Eric Chadwick

Another trick is to reimport the FBX back into Maya, fix any issues with back facing polygons or distorted vertex normals, then re-export.

HarlequinWerewolf

Thanks, I didn't fully realise that the rigged mesh geometry was referenced in Maya so I went back to the original mesh and fixed it through that. Thanks for all the help Eric, I definitely think I've learnt my lesson today!

CheeseOnToast

It's not the history that's the problem,it's the transforms. Make sure you freeze transforms on any object you've duplicated with negative scale in the future. Also, get into the habit of toggling face normals or turning backface culling on in maya before export. It'll show you this kind of error.

HarlequinWerewolf

@CheeseOnToast
Thanks. I'm definitely learnt my lesson on freezing transforms and deleting history, especially after my lecturer talked to me about it. That wasn't the issue this time, but I will always bear it in mind. And yes, it was an issue with the normals and whilst I was toggling normals, because it was a referenced in model, it didn't make a difference, so I have to remember to go back into the original model and do this