Depth peel and transparency

May be this links can help you:
https://gkjohnson.github.io/threejs-sandbox/fat-line-opacity/webgl_lines_fat.html
https://tsherif.github.io/webgl2examples/oit-dual-depth-peeling.html
https://tsherif.github.io/webgl2examples/oit.html
WebGL 2 Order-independent Transparency