How to adjust the starting position and ending poistion in demo.py?

[Blackviking2024]

Hello,
I'm learning how to generate different pose and route using demo.py, and I want to set different starting position and ending postion(lying on the bed, sitting on the chair, eg.) to see the result.
But I'm confused with the coordinate axis of the scene, I tried to adjust the parameters in the lines(showed in the picture) "start=GeometryTransformer.convert_to_6D_rot", "sub=GeometryTransformer.convert_to_6D_rot" and "end=GeometryTransformer.convert_to_6D_rot". However, the results did change, but not as what I expected to be, they end up with some very weird pose and positions. I believe there must be something I didn't fully understand about these codes.
I would like to know if there is a better way to do it? Is there a way to adjust the starting and ending position preciesly?
Thank you very much.