A quick tip for today, I recorded this to help a friend. I thought I could share it here as well.
This is a quite basic in 3D modeling: can I apply rendering materials only on selected faces, not the entire objects?
The answer is yes. Faces are a solid sub object. As we know, we can select sub object by press and hold ctrl key, then click the desired part. Then the rest is the same, just select the material from material library.
You might also want to try using AutoCAD object selection filter.
See how to do it in this video
You probably also want to check the solid history. You can choose solids after a Boolean operation as sub object.