@edsilv/ami.js/examples/vr_crop/convex_geometry.js

<p align="center"> <img src="https://user-images.githubusercontent.com/214063/46479857-4cd66e80-c7f0-11e8-9585-5748409c9490.png" width="60%"> </p>

/**
 * @author Mugen87 / https://github.com/Mugen87
 */

(function() {
  // ConvexGeometry

  function ConvexGeometry(points) {
    THREE.Geometry.call(this);

    this.type = 'ConvexGeometry';

    this.fromBufferGeometry(new ConvexBufferGeometry(points));
    this.mergeVertices();
  }

  ConvexGeometry.prototype = Object.create(THREE.Geometry.prototype);
  ConvexGeometry.prototype.constructor = ConvexGeometry;

  // ConvexBufferGeometry

  function ConvexBufferGeometry(points) {
    THREE.BufferGeometry.call(this);

    this.type = 'ConvexBufferGeometry';

    // buffers

    var vertices = [];
    var normals = [];

    // execute QuickHull

    if (THREE.QuickHull === undefined) {
      console.error('THREE.ConvexBufferGeometry: ConvexBufferGeometry relies on THREE.QuickHull');
    }

    var quickHull = new THREE.QuickHull().setFromPoints(points);

    // generate vertices and normals

    var faces = quickHull.faces;

    for (var i = 0; i < faces.length; i++) {
      var face = faces[i];
      var edge = face.edge;

      // we move along a doubly-connected edge list to access all face points (see HalfEdge docs)

      do {
        var point = edge.head().point;

        vertices.push(point.x, point.y, point.z);
        normals.push(face.normal.x, face.normal.y, face.normal.z);

        edge = edge.next;
      } while (edge !== face.edge);
    }

    // build geometry

    this.addAttribute('position', new THREE.Float32BufferAttribute(vertices, 3));
    this.addAttribute('normal', new THREE.Float32BufferAttribute(normals, 3));
  }

  ConvexBufferGeometry.prototype = Object.create(THREE.BufferGeometry.prototype);
  ConvexBufferGeometry.prototype.constructor = ConvexBufferGeometry;

  // export

  THREE.ConvexGeometry = ConvexGeometry;
  THREE.ConvexBufferGeometry = ConvexBufferGeometry;
})();