In this comment
user253751, user253751 writes:
You cannot create derivative works without permission of the copyright holder (even if you create it and keep it to yourself)
really? That seems unconstitutional or something (in countries that have that). You should be allowed to do whatever you want with your own stuff in your own home.
Is the maker of the comment correct? orOr is the quoted answer (by user gnasher729) quoted correct? What is the US law on making derivative works?