I am currently working on the "Xtion pro live" by using "OpenNI" library. The problem is that the Xtion must be vertically placed (along a wall). The problem is that in this position the user calibration always fails, so it is impossible to get the Skeleton info.
So, I would like to know how to fix this issue, I suppose there is something that I didn't understand about "GetSkeletonCap().RequestCalibration()" or with the "SampleConfig.xml" file. After a lot of research however I am still stuck.
Try moving the user, followed by the camera in 360degree circumference around the subject keeping the vertical positioning of the camera the same all the way through. It may detect optimal angle on the depth sensor. We did this twice with the kinect and it worked.
Also make sure the room is well lit.