How to write a hollow cylinder?

Questions
1

How to write a hollow cylinder? There are no hollow cylinders at the top and bottom I’ve tried many methods, but they don’t work

2

Use 2 rings three.js docs
and 2 Cylinders open ended three.js docs :slightly_smiling_face:

You can also extrude a ring or do things like that: Shapes

( From the Collection of examples from discourse.threejs.org )

3

thanks you are right