FWIW the Intel d435 is NOT a good sensor for doing skeletal tracking from our testing.
Its RMS error rate is to high for accurate sensing of depth data beyond around 1m - this leads to very poor tracking results - and failure of repeat-ability from frame to frame.
The nuitrack system utilizes the depth data only for approximating where the skeletal joints are.
And The depth data is generated inside the sensor on the d435 using a stereo imaging system which basically uses a lot of math to gestimate the depth at each point.
This gestimate is them passed thru a boat load of post processing before nuitrack attempts to process it.
The d415 is a far better sensor for skeletal tracking depths from our current testing.
ALSO as an aide - the POSE in your figure with hands across chest would likely cause all sorts of grief with a d435 - as all the post processing added to the RMS errors at that distance of at least ±5cm would likely result in a mess of incorrect depth data - that would fail to even see the fingers or hands reliably,
If you do want to perserve with the d435 - i would suggest manually changing the default depth map settings in the nuitrack.config - or more ideally in code - so that the rawwidth and rawheight as well as processwidth and processheight are - 848x480 - which seems the optimum size.
Westa