How to write PCD file from topic without loss data?

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I use RGBDSLAM to build the room model and sent topic by menu's 'Graph->Send Model'.

It send model to /rgbdslam/batch_clouds.

I write a receiver to receive that topic ,save it to PCD file, and use pcd_viewer to check.

It shows:

The above is RGBDSLAM's model.

The below is viewer by opening pcd file .

I turn it by moving cursor and it seems loss many data.

My receiver code is:

  #include <ros/ros.h>
  #include "std_msgs/String.h"

  #include <pcl/io/pcd_io.h>
  #include <pcl/point_types.h>


  void pcd_receive_Callback(const sen      sor_msgs::PointCloud2::ConstPtr& msg)
  {
          pcl::PointCloud<pcl::PointXYZRGB> cloud;
          pcl::fromROSMsg(*msg, cloud);
          pcl::io::savePCDFileASCII ("test_pcd.pcd", cloud);      
  }


  int  main (int argc, char** argv)
  {

          ros::init(argc, argv, "pcd_write_topic");
          ros::NodeHandle n;

          ros::Subscriber sub = n.subscribe("/rgbdslam/batch_clouds", 1000, pcd_receive_Callback);
          ros::spin();


          return (0);
  }

How to solve it?

Thank you~