Making a custom collision

Hello. I’ve made a mesh for my game and I want only certain parts of to collide with players. How can I do that?

I’ve tried to scale a capsule into a cylinder (the area I want them to collide with is cylinder shaped) but your tools are designed so I can’t scale on just one axis when making collisions.

How can I do this?

The documentation here could be useful for you. You can also use an external modeling program to create a custom collision, which in many cases would be more efficient.