PBR materials to Vray 3.6

[Joezeta]

A client asked me to convert his 3d models. which have pbr materials, into vray 3.6 materials. Is there a way to use the metallic maps into old materials (3.6 versions and lower) without touching the textures? Plugging the metallic map into the fresnel slot is not a good idea since I don't have a reflection map to drive the metals, nor the metal parts have a black diffuse. To sum up, I'm asking if there's a workflow to use pbr materials into Vray 3.6 and lower (the most important part for me is separating the metallic parts from the non metallic parts, without touching the geometry and the textures)

[joconnell]

Should be possible with a blend material - use your metallic map as a mask to put a second vray material on the top, turn off fresnel on this and put the diffuse map into the reflection map slot. You're pretty much doing a fresnel material for your base and a non fresnel of the same material for your metal and using that metallic map as the blend mask between the two. Pbr material assume for non metals that the reflection colour is always white so the diffuse map is being used for diffuse / albedo colour only. For metal pbr materials the diffuse colour map info is instead used for the metal colour and reflection strength.

[Joezeta]

That's perfect. Thanks.