Three.js 通过屏幕大小计算fov
/** * @name 计算fov * @param {number} z camera.position.z * @param {number} h 设置图像的高 * @param {number} r 宽/高 */function calcFov(z, h, r) { var f; var vertical = h; if (r < 1) { vertical = vertical / r; } f = Math.atan(ver