Why using "with no grad" druing warping?

[ZhouWeikun]

First, thanks for your excellent work.
But, I wonder why "with no grad" is used in the warping process, does it means that the process of warping itself is not differentiable?

[yGaoJiany]

The warping is a hard structure. There is no learnable parameters. So, there is no need to calculate the gradient for the module.

[ZhouWeikun]

Ok, thanks for your answer.