hofk
16
Perhaps the very simple examples help.
https://hofk.de/main/discourse.threejs/2017/BufferGeometry/BufferGeometry.html
https://hofk.de/main/discourse.threejs/2017/Indexed%20BufferGeometry/Indexed%20BufferGeometry.html
from
https://hofk.de/main/discourse.threejs/2017/index2017.html
or
https://hofk.de/main/discourse.threejs/2019/ColorStripeChanging2/ColorStripeChanging2.html
see