some bugs in motion_representation.py

[fivezerojun]

Hi,

Thank you for your excellent work.

I have identified a bug in the process_file function within the motion_representation.py file. Specifically, when rotating the initial position of the human to face the positive direction of the z-axis, both the human position and object position are rotated, while the object rotation is not modified. This discrepancy might impact the data.

Please review the bug and let me know if any further adjustments are needed.

Thank you for your attention.