For our current project, my designer has kindly agreed to re-create the models in Blender directly with a Y-up orientation, which will resolve our immediate display issues. However, I still want to deeply understand the conversion process you outlined. I will carefully examine the samples and information you provided to learn how to solve this purely from the native engineer's side, for future scenarios where modifying the source assets might not be an option. Thanks again for your support!

Thank you for your response. Also, the sample code you explained was very easy to understand. As for the expression “swinging ”underfoot“”, it was written in English through a translator, so the expression may have been incorrect. Please be assured that your question has been resolved.