threejs 世界坐標與屏幕坐標相互轉換

屏幕坐標轉世界坐標:

let pX = (screenPoint.x / this.scene.renderer.domElement.clientWidth) * 2 - 1;
let pY = - (screenPoint.y / this.scene.renderer.domElement.clientHeight) * 2 + 1;

 

//通過調用Vector3的unproject()方法(只有vector3能使用)

//注:pX, pY介於 -1 到1之間

let p = new THREE.Vector3(pX, pY, -1).unproject(this.scene.camera)
return  new THREE.Vector2(p.x,p.y);

 

 

世界坐標轉屏幕坐標

let projector = new THREE.Projector();  

let world_vector = new THREE.Vector3(0,0,1);  

let vector = world_vector.project(this.camera);
let halfWidth = window.innerWidth / 2,

　 halfHeight = window.innerHeight / 2;  

return {  

　　x: Math.round(vector.x * halfWidth + halfWidth),  

　　y: Math.round(-vector.y * halfHeight + halfHeight)  

};