How to show point cloud2 on rviz?

edit

I use fuerte.

I write a topic /output_plane,and I also can find it on rostopic.

  sam@sam:~/code/ros/sam_pcl/sam_ransac$ rostopic echo /output_plane 
  header: 
    seq: 2
    stamp: 
      secs: 1345201963
      nsecs: 71831081
    frame_id: /base_link
  height: 1
  width: 274386
  fields: 
    - 
      name: x
      offset: 0
      datatype: 7
      count: 1
    - 
      name: y
      offset: 4
      datatype: 7
      count: 1
    - 
      name: z
      offset: 8
      datatype: 7
      count: 1
  is_bigendian: False
  point_step: 16
  row_step: 4390176
  data: [27, 18, 111, 191, 82, 184, 46, 191, 59, 223, 151, 191, 0, 0, 128, 63, 219, 133, 110, 191, 41, 232, 46, 191, 213, 9, 152, 191, 0, 0, 128, 63, 93, 254, 107, 191, 223, 55, 46, 191, 210, 111, 151, 191, 0, 0, 128, 63, 248, 223, 106, 191, 236, 250, 45, 191, 100, 59, 151, 191, 0, 0, 128, 63, 173, 47, 106, 191, 237, 13, 46, 191, 199,                                                                              
  ...
  0, 0, 128, 63]
  is_dense: True
  ---

I add point cloud2 and set the topic, but my rviz is still no message comein.

How to fix it?

Thank you~

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Here is all my topics:

   sam@sam:~/code/ros/sam_pcl/sam_ransac$ rostopic list
  /cloud_pcd
  /initialpose
  /move_base_simple/goal
  /output_plane
  /rosout
  /rosout_agg
  /tf
  sam@sam:~/code/ros/sam_pcl/sam_ransac$

And when I close rviz, it becomes:

  sam@sam:~/code/ros/sam_pcl/sam_ransac$ rostopic list
  /cloud_pcd
  /output_plane
  /rosout
  /rosout_agg
  sam@sam:~/code/ros/sam_pcl/sam_ransac$