Get joint direction vector

everyone.

I'm trying to record the movement from a person, frame to frame using the Microsoft Kinect API. For that i'm saving all the joint's position, and besides i would like to get the direction of the vector of the joint. I've seen that the API has something about joint orientation with quaternion matrices, but i don´t know how to use it to get the direction, or should i simply calculate the direction from the coordinates?

Thanks

Solution

Thanks to the answer from Carmine Si - MSFTMicrosoft (MSFT)

"To determine the direction a joint is travelling, then you should just calculate the vector based on the point locations from frame to frame. Typically the other values are for mapping your skeletion from different coordiante spaces so you can do things like the Avateering sample."