How to use 3dmax to paste different materials inside and outside the porcelain bowl, with texture outside and no texture inside?

Let me tell you a simple method.

First, give the model an edit polygon and select faces, select all faces in the bowl, and then separate points.

In this way, the inside and the outside become two objects (pay attention to the separation of objects, not the separation of elements)

It can achieve the effect of different materials inside and outside, and finally add UVW maps inside and outside respectively.

Absolutely original, hope to adopt.