> the copyright law applies and you cannot simply duplicate somebodies likeness
In many countries (like the US), someone's likeness is not covered by copyright law in the first place (in some US jurisdictions, publicity/personality rights may apply, but these are state-law rights and more likely to apply to people, e.g. celebrities, with already-commercialized identities, and against commercial use; they are much more limited than copyright rights.)
For porn/nudes specifically, revenge porn laws (which mostly are aimed at unauthorized release of actual imagery of the targeted kind, but aren’t always narrowly crafted) might also apply.
In many countries (like the US), someone's likeness is not covered by copyright law in the first place (in some US jurisdictions, publicity/personality rights may apply, but these are state-law rights and more likely to apply to people, e.g. celebrities, with already-commercialized identities, and against commercial use; they are much more limited than copyright rights.)
For porn/nudes specifically, revenge porn laws (which mostly are aimed at unauthorized release of actual imagery of the targeted kind, but aren’t always narrowly crafted) might also apply.