code: function () {
  
          this._setPose();
  
          var jointsBoundingBoxes = this._jointsBoundingBoxes;
  
          for (var i = 0; i < this.joints.length; i++) {
              var joint = this.joints[i];
              mat4.multiply(
                  this._skinMatricesSubArrays[i],
                  joint.node.worldTransform.array,
                  this._jointMatricesSubArrays[i]
              );
          }
          if (this.boundingBox) {
              this.boundingBox.min.set(Infinity, Infinity, Infinity);
              this.boundingBox.max.set(-Infinity, -Infinity, -Infinity);
              for (var i = 0; i < this.joints.length; i++) {
                  var joint = this.joints[i];
                  var bbox = jointsBoundingBoxes[i];
                  if (bbox.__updated) {
                      tmpBoundingBox.copy(bbox);
                      tmpMat4.array = this._skinMatricesSubArrays[i];
                      tmpBoundingBox.applyTransform(tmpMat4);
  
                      this.boundingBox.union(tmpBoundingBox);
                  }
              }
          }
      }
docs: Update skinning matrices