Of course, this is location and jurisdiction dependent… but I am reminded of a set of anatomy reference books I saw at Sheridan College when I was there studying animation. They contained people of every size, shape, and description, all photographed in a dispassionate medical manner.
I don’t actually remember whether there were any children in them. If there were, and the books were used as reference for kiddie porn animation, would that be illegal?
I seem to remember news stories of someone being arrested in Canada for drawing kiddie porn, with no actual children involved. I don’t know whether they were convicted.
Depiction of sexual acts by characters identifiable as under the age of consent is illegal in some jurisdictions due to the authorities wanting to forestall the desires of those drawn to such depictions. It is claimed that if you let the pedophiles view “fake” child pornography they will stay interested in it or become “addicted” and go after children to get the “real thing”. This sounds like total bullshit to me, and the exact opposite of what really happens. Pedophilia is a mental disorder, and preventing people from acting innocently on their desires will cause them to experience an even greater desire to perform actions that actually harm children.
In addition, this doesn’t even cover the issue of it being illegal to view sexual acts by sexually mature characters not portrayed by underage human actors. There are good reasons behind making illegal actual sexual congress between an adult and a sexually mature but legally minor child, but I see no good reason this should be extended to simulated minors who are sexually mature; acts by sexually mature individuals are not what pedophiles are interested in.
Cue the “high school girl arrested for child pornography for sending naked pictures of herself to her boyfriend” stories.