Body angles in 3d

I am getting body key points and 3 angle. But I don’t understand which one is I should use. Can u explain angles or is there any method you use from literature. If there is can u share method name?

Hey @OnurS

I went a little bit into detail about keypoints and orientations in this topic: Joint Angle Calculation Methods and Standards

If it doesn’t fully answer your interrogation, please tell us what you want to achieve, we might be able to help.

I am developing a biomechanic ai system so I need every angles meaning. With that I can use your camera to feed my tools. For example there are 3 angle in a joint but which is rotation of arm bone or rotation of history bone? And abductions, flexions?

Hi @OnurS

Sorry for the delay. I’ll try to clarify my other answer a bit.

the angles of each child keypoint are the necessary rotations in its parent’s reference frame. The reference frame is in the coordinate system set in the InitParameters.

That means that the angles’ “meaning” depends on what is set in the coordinate_system attribute of InitParameters, as illustrated here:

All angles at zero should give you the T-Pose.

So, when in T-Pose, all the “local” reference frames share the same “global” orientation.
This means that if a “Right” joint is aligned to X in T-Pose, the corresponding “Left” joint is aligned to -X.

Now that I have written a thousand words, an illustrating picture:

We will update our documentation to comprise something like this, thank you for the feedback.
I hope this helps!