code: function () {
          if (!this.vertexCount || !this.indices) {
              return;
          }
  
          if (this.indices.length > 0xffff) {
              this.indices = new vendor.Uint32Array(this.indices);
          }
  
          var attributes = this.attributes;
          var indices = this.indices;
  
          var attributeNameList = this.getEnabledAttributes();
  
          var oldAttrValues = {};
          for (var a = 0; a < attributeNameList.length; a++) {
              var name = attributeNameList[a];
              oldAttrValues[name] = attributes[name].value;
              attributes[name].init(this.indices.length);
          }
  
          var cursor = 0;
          for (var i = 0; i < indices.length; i++) {
              var ii = indices[i];
              for (var a = 0; a < attributeNameList.length; a++) {
                  var name = attributeNameList[a];
                  var array = attributes[name].value;
                  var size = attributes[name].size;
  
                  for (var k = 0; k < size; k++) {
                      array[cursor * size + k] = oldAttrValues[name][ii * size + k];
                  }
              }
              indices[i] = cursor;
              cursor++;
          }
  
          this.dirty();
      }
docs: Create a unique vertex for each index.