FBX issue with file from Blender to Substance Painter

Wolfer

Hi there so i have this object in blender that i exported, it looks fine in the render and first image shows it in blender how it looks. 
now when i export it to substance painter i get this strange face issue on it as shown here.

you can see it has that face cover over it, why is it doing that. i checked the uv and it doesn't show that and i made sure to apply my rotation and scale. I also tried to put it in unity and it does not have this issue in unity so it does not show in Unity.

CheeseOnToast

Is that face made of triangles and quads only? Or is it an n-gon?

Wolfer

Thats the thing, that face just appears in substance painter, the one that cover the shelves, it doesn't appear in blender. however i notice something, i notice that i had it where my desk and the items on the cabinet were seperate item so when i export the cabinet by itself it doesn't have it, but when i join the items as one and even though the items have a sperate material, that is when the issues happens.

poopipe

Triangulate everything before export

If that doesn't help, export the mesh from painter and look at it in blender - that will help you identify the problem area

Wolfer

Yes that is actually what the problem was. someone from substance painter told me to make the object be a triangulation as substance painter doesn't do well with n-gon so need to triagulate it