Hi. I am subscribing to a point cloud topic having the following data:

height : 480

width: 640

point_step: 16

row_step: 10240

fields: name: "x" offset: 0 datatype: 7, "y" offset: 4 datatype: 7, "z" offset: 8 datatype: 7

Above data means that every x,y,z value is represented as 16 bytes of data. As in fields, we have only x,y,z, so, this means, out of 16 bytes per point, we are only using 12 bytes per point, remaining 4 are set to zero.

Once i output 16 bytes which correspond to 1 point, I am getting following output

[0, 0, 192, 127, 0, 0, 192, 127, 0, 0, 192, 127, 0, 0, 0, 0]

As you can see, last 4 bytes are set to zero which is logical because we only have x,y,z and they represent first 12 bytes. Question is how I can interpret the values of first 12 bytes? what does 12 bytes [0, 0, 192, 127, 0, 0, 192, 127, 0, 0, 192, 127] mean? Another confusing point is for majority of the points, I am getting the same output per point. Shouldn't the X, Y value in the bytes change as i output some other point? What I am expecting is that each 4 bytes should represent the distance value for each x,y,z if i am not wrong..Any clues?

Thanks in advance