There are. The simplest is to have a database of file hashes and compare. Further methods wouldn't likely apply to the 3d printing files because they tend to

There are. The simplest is to have a database of file hashes and compare. Further methods wouldn't likely apply to the 3d printing files because they tend to be specialized around images (making it so that resizing the image, changing the format, or even changing pixels does not defeat the detector), but it would be possible to create new systems that could detect the 3d printing files even after some effort has been made to obscure them. That said, it is and always has been whack a mole, with each side overcoming the advancements of the other only to have their own advancements outdone.