Some Question about the deformation code.

[Pixie8888]

Dear author,

I have some questions about the code in def forward at class FlameDeformationModuleOnlyHead in deformation.py. I understand that you use grid to approximate deformation field. But there are operations that I don't understand:

1. Line 706, what is the purpose of world2grid?
2. Line 707, why do we need to use torch.flip? I think the last dim of x_grids already in xyzorder.
3. Line 734, why x_c = x_c + x_t? I think x_c is already the canonical points.

[lvZic]

have u got it?