Hello,

I'd like to do mocap on the cheap to get a live bones animation from the sensors, most likely a single ASUS Xtion. Is this possible?

This would be for circus performers to check their position in space in real-time and see if they are straight or not for instance.

My understanding of iPi mocap is that you have to record first than process the recording in order to get the bones but can you get a live animation from the sensors? Is the technology there (and cheap) for having a live animation without having to go through a delayed process?

Thanks

There is realtime skeletal tracking for Kinect built in Kinect SDK and for Xtion/Carmine built in OpenNI.
There are numerous programs and plugins for animation software that use these capabilities, including free ones, just google for them.
As you do not need to do motion capture but rather do some evaluation of a pose by eyes, the solutions based on KinectSDK/OpenNI may suit well for your purposes.

For mocap purposes, the accuracy of this realtime tracking is a limiting factor.
iPi Motion Capture implements its own tracking algorithms for better tracking accuracy (and using several sensors simultaneously). But this comes at the cost of processing time. That's why it is not realtime, though we constantly work in improving the performance.