this looks like a clone of line2, which is part of three and you don’t need an extra library for that

import { Line2 } from 'three/examples/jsm/lines/Line2'
threes thick line implementation has a few features missing, i think attenuation for instance, in that case you would normally use meshline by thespite which is maintained here: GitHub - pmndrs/meshline: 🪱 Mesh replacement for THREE.Line
          
const THREE = window.THREE
          
	? window.THREE // Prefer consumption from global THREE, if exists
          
	ShaderLib,
          
	ShaderMaterial,
          
	UniformsLib,
          
	UniformsUtils,
          
	Vector2
Edit fiddle - JSFiddle - Code Playground
I’m trying to replace the line with Line2 to be able to update the line with the mouse position.

I saw the three.meshLine package. But this meshline is a meshGeometry so that I can’t integrate into my previous code which is line.
              
Yes, I checked the same file as you.

There is a problem with the window variable.
https://threejs.org/examples/?q=fat#webgl_lines_fat

I checked this example first. I still can’t be able to implement the three/addons to my website.