Recently, I found a problem when using Vray 5.1. When I browse the forum, I also find that other people have a similar problem, that is, the vray cryptomate in the Vray element. It's going to be very chaotic. After 5.1, using vray crtomatte as a mask selection will be confusing. All FPs are on one layer or one material by default. As shown in the figure below.