Exporting Combined mesh objects gives error

[Anonymous]

I have the following door which is a combined mesh that has 3 materials as you can see in the property editor (wood, glass, lambert7) also listed in the hyper-graph. I've also attached the UV of one of the object of the door prior to the combining and also posted the picture of the UV layout after combining them.

I exported the object using the 2017 fbx exporter version and got the following error white exporting:
LOG: [WARNING] Unable to export some material(s) - The plug-in does not support the following material types:
Material will be exported as a grey Lambert material.  What could I be doing wrong here?

[damaggio]

FBX can only export lamberts , phongs and blinns

[damaggio]

it wont export any Arnold shaders.

Try to export with groups instead of combining objects.

[Anonymous]

I only used lambert for all the materials. 

So I seperated the objects and grouped them into a single node. I exported the node and got the same result.

[damaggio]

How does it open in the other software?

[Anonymous]

I am importing it to Unreal, and I see all the objects with each of their materials which is fine but now I have 4 different models for a single door. 

I tried re combining them and exporting them, but again the FBX exported said it doesn't support the material "empty string".

[damaggio]

It's better to shade in Unity not in Maya, combine only the objects that have the same material, glass parts for instance should be separate.

See if that works.

[damaggio]

Unreal I mean.

[Anonymous]

Thanks for the recomendation. So is there a bug in Maya's FBX export function or it's just that the format doesn't support this feature?