localPositionToTextCoords(position, target = new Vector2()) {
    target.copy(position) //simple non-curved case is 1:1
    const r = this.curveRadius
    if (r) { //flatten the curve
      target.x = Math.atan2(position.x, Math.abs(r) - Math.abs(position.z)) * Math.abs(r)
    }
    return target
  }
Translate a point in local space to an x/y in the text plane.