– When using a model in max format, if necessary, enable the turbosmooth modifier.
– When using a model in obj format, add a turbosmooth modifier if necessary.
– For those who work in a VRay version lower than 3.1, be careful, in the materials in the BRDF section there is Microfaset GTR (GGX), if your version is older than 3.1, then the BRDF field will be empty. Choose Blinn, Phong or Ward – which is preferable for you.
– For Corona render, it is recommended to install a version of at least 1.5, since the glossiness of materials is configured with PBR in mind.