Suppressing 3D cloud to 2D cloud

edit

Hi, I used the gmapping using turtlebot to create the map of the environment. I understand that the turtlebot creates a fake laser which is suppressed 2D cloud from the kinect. Assuming that the kinect tf frame is such that ^ is x and > is y and into the screen is z. I want a 2D cloud in yz plane similar to laser. But every point in this plane should give the obstacle that is present in varying x also.

For example if there is a hanging obstacle from x = 4 to 5, with y = -1 to 1 and z = 2. Then fake laser cloud should have cloud in yz plane at y= - 1 to 1.

My question here is: a) Is this what done in the fake laser included in the turtlebot launch?

or b) is there any other package that does this?

or c) will this work in real time if i wrote it on my own?

Any suggestions and pointers will be much appreciated!!!

Thanks, Karthik

What does the min-height n max-height in the launch file signify?

 <!-- Fake Laser -->
  <node pkg="nodelet" type="nodelet" name="kinect_laser" args="load pointcloud_to_laserscan/CloudToScan openni_manager" respawn="true"
  output="screen">
    <param name="output_frame_id" value="/kinect_depth_frame"/>
    <!-- heights are in the (optical?) frame of the kinect -->
    <param name="min_height" value="-0.15"/>
    <param name="max_height" value="0.15"/>
    <remap from="cloud" to="/cloud_throttled"/>
  </node>

I have written as piece of code that results in 640 valid cloud points and the rest to be nans. I give this as the input to the throttle instead of the /camera/depth/points. Its not helping me out as the laser scan at the end is very minimal and the scan matching is failing. Any suggestions ??