Question about cloth material optimization

[y-zheng18]

Hi,
Thanks for the awesome work! I have a question regarding optimizing the cloth material parameters. I run the tshirt demo and dress demo, and it seems that the optimized K_triangle or K_bending is almost the same with the random assigned initial value. Does this make sense? Besides, in the dress demo, the density changes to min value (0.01) after the first iteration, but after that it becomes larger again and the dress angle decreases, which seems weird. Could there be something wrong with my code or configuration?