Source code of Inertial Motion Capture/Kinematics and its visualization

I am looking for an example of source code of Inertial Motion Capture/Kinematics and its visualization. Especially, I am interested in the example of a body of skeleton in 3D.

For examples:

I have been trying this with IMU 9DOFs + Arduino for the Inertial Motion Capture and Processing (+ OpenGL) for the visualization. I have looked for this long time, but I have not found any significant examples of source codes yet. Does anyone know such an example or the references which are well commented in details? If it is not in Arduino or Processing, it may be a different language (Jave, C++, etc.), though. Thank you in advance.

I'm looking at using this sort of module to deliver position information, but from the research I have done, the accuracy of the data from these consumer modules, is not good enough to calculate position by inertial navigation techniques.

There is some research with using barometric data as well as the 9 axis data, which is what I intend to use. However this still isn't very accurate,

So is suspect the current state of this technology would not allow it to be used for the application you suggest.

However it would require more research by you, to truly determine if this hypothesis is correct, or whether there are any tricks that can be used to improve the performance of these devices.

For the future the manufacturers may release the compiler for the dsp inside the sensor devices and may allow their use for more applications