javascript - 如何通过 three.js 中的轨道控制偏移旋转对象？

Question

我想像这样控制对象:

现在相机围绕Y坐标移动，但需要围绕NEW Y移动。代码在这里:

var material = new THREE.MeshLambertMaterial({color: 0x00ff00});
var cube = new THREE.Mesh(geometry, material);
scene.add(cube);
var controls = new THREE.OrbitControls(camera);
cube.position.x = 300;
// controls.target = THREE.Vector3(300, 0, 0);

我发现 target 选项可以设置控件的焦点，但是如果我添加以下代码:controls.target = THREE.Vector3(300, 0, 0); 对象返回屏幕的中心，但它应该在右边缘。

此外，当我将 new THREE.OrbitControls(camera); 设置为 new THREE.OrbitControls(cube); 并添加 controls.target = THREE .Vector3(300, 0, 0); 控件不起作用，但是当我设置 controls.target = THREE.Vector3(301, 0, 0); 它被管理但是不像相机

Answer 1

OrbitControls.target设置控件的焦点，.object 围绕它旋转。但这是一个手动操作。如文档中所述 OrbitControls.update()必须在对相机的变换进行任何手动更改后调用。

例如

controls.target = new THREE.Vector3(1, 0, 0)
controls.update();

看例子:

(function onLoad() {
  var container, camera, scene, renderer, controls;
  
  init();
  animate();

  function init() {
    container = document.getElementById('container');
    
    renderer = new THREE.WebGLRenderer({
      antialias: true
    });
    renderer.setPixelRatio(window.devicePixelRatio);
    renderer.setSize(window.innerWidth, window.innerHeight);
    renderer.shadowMap.enabled = true;
    container.appendChild(renderer.domElement);

    camera = new THREE.PerspectiveCamera(70, window.innerWidth / window.innerHeight, 1, 100);
    camera.position.set(0, 1.0, -4);
    
    scene = new THREE.Scene();
    scene.background = new THREE.Color(0xffffff);
    scene.add(camera);
    window.onresize = resize;
    
    var ambientLight = new THREE.AmbientLight(0x404040);
    scene.add(ambientLight);

    var directionalLight = new THREE.DirectionalLight( 0xffffff, 0.5 );
    directionalLight.position.set(1,2,1.5);
    scene.add( directionalLight );

    controls = new THREE.OrbitControls(camera, container);
    controls.target = new THREE.Vector3(3, 0, 0)
    controls.update();
    controls.autoRotate = true;
    controls.autoRotateSpeed = 5.0
            
    var axis = new THREE.AxesHelper(1000);
    scene.add(axis);

    var material = new THREE.MeshPhongMaterial({color:'#b090b0'});
    var geometry = new THREE.BoxGeometry( 1, 1, 1 );
    var mesh = new THREE.Mesh(geometry, material);

    scene.add(mesh);
  }


  function resize() {   
    var aspect = window.innerWidth / window.innerHeight;
    renderer.setSize(window.innerWidth, window.innerHeight);
    camera.aspect = aspect;
    camera.updateProjectionMatrix();
  }

  function animate() {
    requestAnimationFrame(animate);
    controls.update();
    render();
  }

  function render() {
    renderer.render(scene, camera);
  }
})();

<script src="https://cdn.jsdelivr.net/npm/three@0.115/build/three.js"></script>
<script src="https://cdn.jsdelivr.net/npm/three@0.115/examples/js/controls/OrbitControls.js"></script>

<div id="container"></div>