Three.JS 從世界坐標系轉換到屏幕坐標系

var projector = new THREE.Projector();  
  
var world_vector = new THREE.Vector3(0,0,1);  
  
var vector = projector.projectVector(world_vector, camera);  
  
var halfWidth = window.innerWidth / 2;  
var halfHeight = window.innerHeight / 2;  
  
var result = {  
  
    x: Math.round(vector.x * halfWidth + halfWidth),  
    y: Math.round(-vector.y * halfHeight + halfHeight)  
  
};