/* world position to screen position
* v3: Vector3
* camera: Camera
* */
function wordPosToScreen(object,camera) {
var vector = new THREE.Vector3();
var widthHalf = 0.5 * window.innerWidth;
var heightHalf = 0.5 * window.innerHeight;
object.updateMatrixWorld(); /*这段代码是重要的在获取前先更新下对象的世界坐标/世界矩阵*/
vector.setFromMatrixPosition(object.matrixWorld);
vector.project(camera);
vector.x = (vector.x * widthHalf) + widthHalf;
vector.y = -(vector.y * heightHalf) + heightHalf;
return {
x: vector.x,
y: vector.y
};
}