bytev-charts-beta/lib/plugin/three.js/examples/js/exporters/STLExporter.js

基于echarts和JavaScript及ES6封装的一个可以直接调用的图表组件库，内置主题设计，简单快捷，且支持用户自定义配置； npm 安装方式: npm install bytev-charts 若启动提示还需额外install插件,则运行 npm install @babel/runtime-corejs2 即可;

import "core-js/modules/es.array-buffer.constructor.js";
import "core-js/modules/es.array-buffer.slice.js";
import "core-js/modules/es.object.to-string.js";
import "core-js/modules/es.data-view.js";
console.warn("THREE.STLExporter: As part of the transition to ES6 Modules, the files in 'examples/js' were deprecated in May 2020 (r117) and will be deleted in December 2020 (r124). You can find more information about developing using ES6 Modules in https://threejs.org/docs/#manual/en/introduction/Installation.");
/**
 * Usage:
 *  var exporter = new THREE.STLExporter();
 *
 *  // second argument is a list of options
 *  var data = exporter.parse( mesh, { binary: true } );
 *
 */

THREE.STLExporter = function () {};

THREE.STLExporter.prototype = {
  constructor: THREE.STLExporter,
  parse: function () {
    var vector = new THREE.Vector3();
    var normalMatrixWorld = new THREE.Matrix3();
    return function parse(scene, options) {
      if (options === undefined) options = {};
      var binary = options.binary !== undefined ? options.binary : false; //

      var objects = [];
      var triangles = 0;
      scene.traverse(function (object) {
        if (object.isMesh) {
          var geometry = object.geometry;

          if (geometry.isBufferGeometry) {
            geometry = new THREE.Geometry().fromBufferGeometry(geometry);
          }

          if (geometry.isGeometry) {
            triangles += geometry.faces.length;
            objects.push({
              geometry: geometry,
              matrixWorld: object.matrixWorld
            });
          }
        }
      });

      if (binary) {
        var offset = 80; // skip header

        var bufferLength = triangles * 2 + triangles * 3 * 4 * 4 + 80 + 4;
        var arrayBuffer = new ArrayBuffer(bufferLength);
        var output = new DataView(arrayBuffer);
        output.setUint32(offset, triangles, true);
        offset += 4;

        for (var i = 0, il = objects.length; i < il; i++) {
          var object = objects[i];
          var vertices = object.geometry.vertices;
          var faces = object.geometry.faces;
          var matrixWorld = object.matrixWorld;
          normalMatrixWorld.getNormalMatrix(matrixWorld);

          for (var j = 0, jl = faces.length; j < jl; j++) {
            var face = faces[j];
            vector.copy(face.normal).applyMatrix3(normalMatrixWorld).normalize();
            output.setFloat32(offset, vector.x, true);
            offset += 4; // normal

            output.setFloat32(offset, vector.y, true);
            offset += 4;
            output.setFloat32(offset, vector.z, true);
            offset += 4;
            var indices = [face.a, face.b, face.c];

            for (var k = 0; k < 3; k++) {
              vector.copy(vertices[indices[k]]).applyMatrix4(matrixWorld);
              output.setFloat32(offset, vector.x, true);
              offset += 4; // vertices

              output.setFloat32(offset, vector.y, true);
              offset += 4;
              output.setFloat32(offset, vector.z, true);
              offset += 4;
            }

            output.setUint16(offset, 0, true);
            offset += 2; // attribute byte count
          }
        }

        return output;
      } else {
        var output = '';
        output += 'solid exported\n';

        for (var i = 0, il = objects.length; i < il; i++) {
          var object = objects[i];
          var vertices = object.geometry.vertices;
          var faces = object.geometry.faces;
          var matrixWorld = object.matrixWorld;
          normalMatrixWorld.getNormalMatrix(matrixWorld);

          for (var j = 0, jl = faces.length; j < jl; j++) {
            var face = faces[j];
            vector.copy(face.normal).applyMatrix3(normalMatrixWorld).normalize();
            output += '\tfacet normal ' + vector.x + ' ' + vector.y + ' ' + vector.z + '\n';
            output += '\t\touter loop\n';
            var indices = [face.a, face.b, face.c];

            for (var k = 0; k < 3; k++) {
              vector.copy(vertices[indices[k]]).applyMatrix4(matrixWorld);
              output += '\t\t\tvertex ' + vector.x + ' ' + vector.y + ' ' + vector.z + '\n';
            }

            output += '\t\tendloop\n';
            output += '\tendfacet\n';
          }
        }

        output += 'endsolid exported\n';
        return output;
      }
    };
  }()
};