o3djs.picking.TransformInfo.prototype.update = function() {
    var newChildTransformInfos = {};
    var newShapeInfos = {};
    var children = this.transform.children;
    for (var c = 0; c < children.length; c++) {
      var child = children[c];
      var transformInfo = this.childTransformInfos[child.clientId];
      if (!transformInfo) {
        transformInfo = o3djs.picking.createTransformInfo(child, this);
      } else {
        // clear the boundingBox so we'll regenerate it.
        transformInfo.boundingBox = null;
      }
      transformInfo.update();
      newChildTransformInfos[child.clientId] = transformInfo;
    }
    var shapes = this.transform.shapes;
    for (var s = 0; s < shapes.length; s++) {
      var shape = shapes[s];
      var shapeInfo = this.shapeInfos[shape.clientId];
      if (!shapeInfo) {
        shapeInfo = o3djs.picking.createShapeInfo(shape, this);
      } else {
        // unless the vertices or elements change there is no need to
        // recompute this.
        // shape.update();
      }
      newShapeInfos[shape.clientId] = shapeInfo;
    }
  
    // o3djs.picking.dprint(
    //   'num Children: ' + children.length + '\n');
    // o3djs.picking.dprint(
    //   'num Shapes: ' + shapes.length + '\n');
  
    this.childTransformInfos = newChildTransformInfos;
    this.shapeInfos = newShapeInfos;
  
    var boundingBox = null;
    for (var key in newShapeInfos) {
      var shapeInfo = newShapeInfos[key];
      var box = shapeInfo.getBoundingBox().mul(this.transform.localMatrix);
      if (!boundingBox) {
        boundingBox = box;
      } else if (box) {
        boundingBox = boundingBox.add(box);
      }
    }
  
    for (var key in newChildTransformInfos) {
      var transformInfo = newChildTransformInfos[key];
      // Note: If there is no shape at the leaf on this branch
      // there will be no bounding box.
      var box = transformInfo.getBoundingBox();
      if (!boundingBox) {
        boundingBox = box.mul(this.transform.localMatrix);
      } else if (box) {
        boundingBox = boundingBox.add(box.mul(this.transform.localMatrix));
      }
    }
  
    this.boundingBox = boundingBox;
  };