bytev-charts/lib/plugin/three.js/examples/js/curves/NURBSSurface.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;

console.warn("THREE.NURBSSurface: 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.");
/**
 * NURBS surface object
 *
 * Implementation is based on (x, y [, z=0 [, w=1]]) control points with w=weight.
 **/

THREE.NURBSSurface = function (degree1, degree2, knots1, knots2
/* arrays of reals */
, controlPoints
/* array^2 of Vector(2|3|4) */
) {
  this.degree1 = degree1;
  this.degree2 = degree2;
  this.knots1 = knots1;
  this.knots2 = knots2;
  this.controlPoints = [];
  var len1 = knots1.length - degree1 - 1;
  var len2 = knots2.length - degree2 - 1; // ensure Vector4 for control points

  for (var i = 0; i < len1; ++i) {
    this.controlPoints[i] = [];

    for (var j = 0; j < len2; ++j) {
      var point = controlPoints[i][j];
      this.controlPoints[i][j] = new THREE.Vector4(point.x, point.y, point.z, point.w);
    }
  }
};

THREE.NURBSSurface.prototype = {
  constructor: THREE.NURBSSurface,
  getPoint: function getPoint(t1, t2, target) {
    var u = this.knots1[0] + t1 * (this.knots1[this.knots1.length - 1] - this.knots1[0]); // linear mapping t1->u

    var v = this.knots2[0] + t2 * (this.knots2[this.knots2.length - 1] - this.knots2[0]); // linear mapping t2->u

    THREE.NURBSUtils.calcSurfacePoint(this.degree1, this.degree2, this.knots1, this.knots2, this.controlPoints, u, v, target);
  }
};