Trying to render polygon hair with transparency I get this artifact: What I've checked so far: renderer.sortObjects is true. The hair's material.side is THREE.DoubleSide. Set material.alphaTest=0.5 - reduced the problem but some artifacts are still visible. How do I debug this?

Blending artifacts when rendering polygon hair with Three.js

Trying to render polygon hair with transparency I get this artifact:

Polygon hair artifacts

What I've checked so far:

renderer.sortObjects is true.
The hair's material.side is THREE.DoubleSide.
Set material.alphaTest=0.5 - reduced the problem but some artifacts are still visible.

How do I debug this?