Dtrack and avatar -coordinates question

[sircedric4]

Originally Posted by sircedric4

Thanks, I pretty much had the same conclusion but was having a hard time calculating what that rotation difference was, which is why I asked for the coordinate axis image. Thank you for the code, that helped as well as letting me know that the avatar initial position is 0 for all the coordinates involved. I am still trying to figure out the math but this did answer my question.

The math for my problem is still driving me crazy. I obviously do not have a handle on whether to use quaternion, axis angle or euler to easily adjust my axis to match those of the hand. I am attaching a picture of the two points and how they relate to each other. The smaller red-blue-green lines is the avatar axis system, the larger red-blue-green lines are what my Dtrack is giving me for my euler position.

As you can see, I need to rotate the system around the green axis by 90 degrees in one direction, and then rotate the system 90 degrees around the new position of the blue axis in order to get my axis to match the avatar axis.

Can someone point me to a good, easy to understand reference/web site on how to get what rotation value I need, and which of the coordinate systems in Vizard will be easiest to use to do the rotation. It has not been as simple as just subtracting 90 from the euler numbers that represent the green and blue axis. I think I am probably supposed to use quarternion but I really could use some help.