three.js - 如何在 ThreeJS 中获取边界框的角点？

Question

我创建了 Object3D 并在其中添加了四个立方体几何体，并计算了包含四个立方体对象的 Object3D 的边界框，并使用 BoxHelper 查看边界框是否正常工作。现在我想要边界框的所有角点(即 XYZ，角点坐标)。

基本上，我试图在我的四个立方体从边界框中心的初始位置到达边界框的四个角时实现爆炸和内爆效果。

var objectContainer = new THREE.Object3D();
scene.add(objectContainer);
var objectAGeom = new THREE.BoxGeometry(1,1,1);

objectAMesh = new THREE.Mesh(objectAGeom, objectAMaterial);   

scene.add(objectAMesh);
objectContainer.add(objectAMesh);


var objectBGeom = new THREE.BoxGeometry(1,1,1);

var objectBMesh = new THREE.Mesh(objectBGeom, objectBMaterial);


scene.add(objectBMesh);
objectContainer.add(objectBMesh);

var objectCGeom = new THREE.BoxGeometry(1,1,1);

var objectCMesh = new THREE.Mesh(objectCGeom, objectCMaterial);

scene.add(objectCMesh);
objectContainer.add(objectCMesh);

var objectDGeom = new THREE.BoxGeometry(1,1,1);

var objectDMesh = new THREE.Mesh(objectDGeom, objectDMaterial);

scene.add(objectDMesh);
objectContainer.add(objectDMesh);`                            
helper = new   THREE.BoxHelper(objectContainer);
helper.material.color.set(0xbbddff);
scene.add(helper);

boundingBox = new  THREE.Box3();
boundingBox.setFromObject(objectContainer);`

Answer 1

对于初学者来说，将网格添加到场景，然后立即将其添加到 Object3D 会使第一个命令无用，因为网格一次只能有一个父级。

scene.add(objectAMesh); // This does nothing...
objectContainer.add(objectAMesh); // Because you're immediately adding it here

ObjectContainer 已经在场景中，因此您不需要通过两种不同的方式将 Meshes 添加到场景中。

其次，您需要使用 THREE.Box3 来获取边界框，您已经在这样做了。这会给你 the .min and .max values of the BoundingBox .您可以使用它来推断所有 8 个角:

boundingBox = new  THREE.Box3();
boundingBox.setFromObject(objectContainer);

const low = boundingBox.min;
const high = boundingBox.max;

const corner1 = new THREE.Vector3(low.x,    low.y,  low.z);
const corner2 = new THREE.Vector3(high.x,   low.y,  low.z);
const corner3 = new THREE.Vector3(low.x,    high.y, low.z);
const corner4 = new THREE.Vector3(low.x,    low.y,  high.z);

const corner5 = new THREE.Vector3(high.x,   high.y, low.z);
const corner6 = new THREE.Vector3(high.x,   low.y,  high.z);
const corner7 = new THREE.Vector3(low.x,    high.y, high.z);
const corner8 = new THREE.Vector3(high.x,   high.y, high.z);