如何合并文本、球体和盒子几何？

Posted 2023-03-16

【中文标题】如何合并文本、球体和盒子几何？

【英文标题】：How to merge Text, Sphere and Box Geometry?

【发布时间】：2021-10-28 21:19:47

【问题描述】：

我正在尝试合并文本、球体和框几何体，这样我就可以只用一个设置位置来改变所有位置。条件是我必须使用 BufferGeometry。合并球体和框时一切正常，但合并文本几何时出错。

上面写着Uncaught (in promise) TypeError: Cannot read property 'x' of undefined at X.BufferGeometry.fromGeometry

let modelGeometry = new THREE.Geometry();
const globalMaterial = new THREE.MeshBasicMaterial( color: 0xff0000 );
const head = new THREE.SphereGeometry(0.5, 32, 16);
const body = new THREE.SphereGeometry(0.5, 32, 16);
const textGeometry = new THREE.TextGeometry("text ID", 
  font: "monaco",
  size: 1,
  height: 0,
  curveSegments: 3,
);

textGeometry.computeBoundingBox();
textGeometry.mergeVertices();

const textMaterial = new THREE.MeshBasicMaterial( color: 0xff0000 );

const workerId = new THREE.Mesh(textGeometry, textMaterial);

const headMesh = new THREE.Mesh(head, globalMaterial);
const bodyMesh = new THREE.Mesh(body, globalMaterial);
headMesh.matrix.setPosition(new THREE.Vector3(0, 0, 3));
bodyMesh.matrix.scale(new THREE.Vector3(1, 1, 4));
modelGeometry.merge(headMesh.geometry, headMesh.matrix);
modelGeometry.merge(bodyMesh.geometry, bodyMesh.matrix);
modelGeometry.merge(workerId.geometry, workerId.matrix);

const bufGeometry = new THREE.BufferGeometry().fromGeometry(modelGeometry);

this.human = new THREE.Mesh(bufGeometry, globalMaterial);
this.modelBuilder.addMesh(this.human);

【问题讨论】：

您使用的是 Three.js 的哪个版本？从 r125 开始，THREE.Geometry() 已从框架核心移出。现在所有的几何都是缓冲几何。要合并它们，您必须使用 BufferGeometryUtils.mergeBufferGeometries( _array_ );

我使用 r71 ThreeJS 版本，它是 Autodesk Forge 的一个库。

【参考方案1】：

参考这个discussion 文本几何中缺少的东西。需要添加computeVertexNormals();

modelGeometry.merge(headMesh.geometry, headMesh.matrix);
modelGeometry.merge(bodyMesh.geometry, bodyMesh.matrix);
modelGeometry.merge(humanIdMesh.geometry, humanIdMesh.matrix);
modelGeometry.computeVertexNormals();
const humanModel = new THREE.BufferGeometry().fromGeometry(modelGeometry);