Do the parameters of the NeRF model change during the estimation of the pose?

[JingruiYu]

Is this net a NeRF model for this line of code in the pose_estimation.ipynb file?
# Encode. net.encode( input_image.unsqueeze(0), input_pose.unsqueeze(0).to(device=device), focal, )

Are the parameters of this NeRF model modified during iteration?

On the other hand, the net.encode seems does the same thing in each loop, but why can't move this code outside the loop?