Confused. Metallic parts becomed black. How to setup this in vray 3dsmax?

[Silverbell]

I have made my texturing in substance painter by using metal roughness workflow. Then I exported my textures with "Vray" config. So I got "diffuse", "glosiness", and "reflection" maps. My object has some metallic parts and because of that my "diffuse" map becomed black on those parts that were metallic. At first I was very confused why this is happened, because previously I used "metal roughness" config and it was exporting not "Diffuse" but "Base Color" map and on the "Base color" map the metallic parts of the object dont become black. But then I googled it and its turned out that this is not a bug but an expected behaviour (probably to confuse as much people as posssible). But anyways my question is what am I suppose to do now with this Diffuse map that has the black color in the places which supposed to be metallic and not the black! How do I setup this in the 3dsmax in vray correctly now? So i have this wrong "diffuse" map and also i have "glosiness" and "reflection" map. How do i connect them to the VRayMtl node so that my metallic parts of the object will become metallic (not black) and not just metallic but also have that nice flakes of that metalic material that was used by me in Substance painter? Thanks

[Silverbell · Accepted solution]

sorted after whatching this tutorial - https://www.youtube.com/watch?v=TXfwpySJAgk&t=9s

It seams like I should also use IOR map and it defines where the metalic parts of the object are. Strange. I thought that IOR maps are only used when dealing with water or glass materials. So still confused why I whould use IOR map to define where the metal parts are. Will try to find more info about it.