Unproject the vector and gives back screen coordinates x,y

THREE-WorldToScreen.js

import { Vector3 } from 'three'

const v = new Vector3()

export default (v3, camera) => {
  v.copy(v3)
  v.project(camera)

  return {
    x: v.x * window.innerWidth * 0.5 + window.innerWidth * 0.5,
    y: -v.y * window.innerHeight * 0.5 + window.innerHeight * 0.5
  }
}