[FGLTFJsonMaterial](API\Plugins\GLTFExporter\Json\FGLTFJsonMaterial) * AddUniqueMaterial ( const [UMaterialInterface](API\Runtime\Engine\Materials\UMaterialInterface) * Material, const [UStaticMeshComponent](API\Runtime\Engine\Components\UStaticMeshComponent) * StaticMeshComponent, int32 LODIndex, int32 MaterialIndex )