Who works with V-Ray version “ lower than 3.1, pay attention to materials section BRDF (microfaset GTR(GGX)), if your version is older than 3.1 – this section will be empty , and you have to choose : Blinn, Ward or Phong, d dependence on material.”

For Corona render , it is “ recommended to install a version of at least 1.5, since the glossiness of materials is configured considering PBR.”