How can I get the skeleton model files?

[JunxuanBai]

Hello, I have some questions about the .json files? If I don't have these .json files, how can I create them?

[eherr]

Hi

sorry for the missing documentation. The model file stores the assignment of joints to a standard skeleton. Additionally, it stores for each mapped joint a local coordinate system. This coordinate system is used during the retargeting to calculate the coordinate system transformation matrix between corresponding joints of different skeletons. In order to work these coordinate systems need to be set up so that the global axes of corresponding joints are the pointing in the same direction for different skeletons when they have the same pose, e.g. the t-pose.

To create a skeleton model file you can use the following tool:
https://github.com/eherr/motion_preprocessing_tool

You can load a BVH file via drag and drop, and open the skeleton model editor by pressing on the "Add New Model" button in the animation player widget on the right.

The skeleton editor displays the first frame of the loaded motion in a new window. There you can assign a standard name to each joint. You need to assign at least the left hip, right hip, spine, root and neck joint. After you have done that you can create a guess of the coordinate system for each joint and manually adjust its global rotation in the current pose.

Here is a screenshot of the editor with the buttons highlighted:

When you press accept the the model file is stored in the data/skeletons directory of the working directory.

[JunxuanBai]

Thank you!