Height Map xyz coordinates

edit

Hello, I'm using velodyne height map , so far i am struggling to only view the x,y,z coordinates of obstacles. even once I try to edit on heightmap.cpp file nothing changing in output. what could be best way to as to only view the coordinates without the raw data matrix. if anyone can clarify to me what is meant by offset for instance this means that the value of the x is on zero position in the raw data matrix.

  seq: 22
  stamp: 
    secs: 1518471618
    nsecs: 669806000
  frame_id: velodyne
height: 1
width: 480
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
  - 
    name: intensity
    offset: 16
    datatype: 7
    count: 1
is_bigendian: False
point_step: 32
row_step: 15360

thank you