Reading float from Float32 data from kinect pointcloud2

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Hi everyone,

I am trying to get the xyz data from a pointcloud2 msg in bagfile created with kinect. So far I seem to be getting quite far, but at this point I'm a bit uncertain.

The Pointfield in the pointcloud2 shows that the data should consist of three Float32 (std_msgs::Float32) values for x,y & z. However the pointstep parameter shows 16 bytes are being used per datapoint. Are the first 12 bytes used for the x,y,z Float32 values and are the last 4 bytes overhead, or is this built up differently?

Result for information parameters:

width = 320 height = 240 row step = 5120 point step = 16

Fields[0] --> name: x offset: 0 datatype: 7 count: 1

Fields[1] --> name: y offset: 4 datatype: 7 count: 1

Fields[2] --> name: z offset: 8 datatype: 7 count: 1

Little code snippet:

typedef sensor_msgs::PointCloud2 PointCloud;
typedef PointCloud::Ptr PointCloudPtr;
typedef std_msgs::Float32 Float32;

//get the pointcloud loaded from view_it
PointCloud cloud_t;
PointCloudPtr cloud = view_it->instantiate<PointCloud> ();
cloud_t = *cloud;

//get pointer to first element of dataline 20 and typecast it to Float32
unsigned char *dataptr = &cloud_t.data[20];
entryptr = (Float32 *) dataptr;

//print the value of x (if its in first 4 bytes)
std::cout << "data x float is " << (*entryptr).data <<std::endl;