用Three.js Raycaster实现文件的下载

var scene = new THREE.Scene();

var loader = new THREE.OBJLoader();
loader.load('file.obj', function (object) {
    scene.add(object);
});

var raycaster = new THREE.Raycaster();
var mouse = new THREE.Vector2();

function onMouseMove(event) {
    // 根据鼠标位置计算标准化设备坐标
    mouse.x = (event.clientX / window.innerWidth) * 2 - 1;
    mouse.y = - (event.clientY / window.innerHeight) * 2 + 1;

    // 更新射线的起点和方向
    raycaster.setFromCamera(mouse, camera);
}

window.addEventListener('mousemove', onMouseMove, false);

function onDocumentClick(event) {
    // 检测射线和物体的交互
    var intersects = raycaster.intersectObjects(scene.children, true);
    if (intersects.length > 0) {
        // 如果存在交互，执行相关操作，比如下载文件
        downloadFile('file.obj');
    }
}

window.addEventListener('click', onDocumentClick, false);

function downloadFile(fileUrl) {
    var link = document.createElement('a');
    link.href = fileUrl;
    link.download = 'file.obj';
    link.click();
}