Assuming this thread is will still be here by the time I finish replying and was not deleted due to discussion of "child porn", I will attempt to answer this.

Quote - I'm interested in what you feel and think about the ethical, artistic and legal issues raised with regards to 3D-CGI, facial beauty, "apparent age" and "babyfacedness".

There has to be a line drawn somewhere to protect children. With graphic media the way it is, it's very easy to manipulate photos to look like 3D generated images, and it's very easy (at least for some) to work 3D images to look absolutely real. See this particular site for many examples of the later.

http://forums.cgsociety.org/

Like I said earliery, there is no way to prove the age of the figure in the image, so the decision has to be made based on visual input only.

Quote - "The determining factor for age is most often decided based on the face", you write. Do you mean only here on 'rosity?

Quote - If we take a wider perspective, I would like to ask two questions: 1) Do we work that way, as humans? Is that how our perception of apparent age works?

I'll answer those two questions together.

Here and in general.  When you see someone on the street you don't have their photo ID in front of them. All you have is their face and body and based on that you subjectively determine their age based on how old you think they look.

Case in point. Some people when they go to a bar are asked for ID, while others aren't.  For those that are asked it's  because they visually "look" younger than the legal age required to be in the  bar.  For me I never had that problem. I started going to bars when I was 15 because I loved music and I loved to dance. I never once got asked for ID. Whereas my cousin who is a year older than me was constantly asked because he had a "baby face" and looked much younger.

Quote - 2) How ought good laws be written on that topic, regardless of society? Ought good laws be based on arbitrary judgement, as that "I know it when I see it"-judge put it?

Earlier this year Anton posted a link to a news story about a State in the US that passed a law about just that. Apparently the child porn law in that particular state was amended to not include computer generated images.   I tried to find the link to the story, but I can't find it. However I did do a google search and found some articles:

House bans "morphed" child pornography

Child pornography is an explosively sensitive issue

US court quashes child porn lawUS Supreme Court upholds decision that finds ...... unconstitutional

Detecting Computer Generated Porn

Computer Generate Child Porn ... Gap in US Law

The 1996 Act upheald by a Federal Judge - August 1997
Here is a quote from the above article

Quote -The US Child Pornography Prevention Act of 1996 which bans computer-generated sexual images of children and porn featuring adults who are depicted as minors was upheld by a federal judge on the 12th of August 1997. Rejecting arguments by sex film distributors and the American Civil Liberties Union, U.S. District Judge Samuel Conti said the new law protects children from sexual exploitation without violating freedom of speech.  

"Even if no children are involved in the production of sexually explicit materials, the devastating ... effect that such materials have on society and the well-being of children merits the regulation of such images," Conti wrote in the first court ruling on the law’s validity.

He dismissed the ACLU’s fears that the law could criminalize a film of "Romeo and Juliet" or a doctor’s sex education manual. Only pictures that are marketed as child pornography are covered by the law, Conti said.

There is a case in Canada that has been going on for years!  It's setting a dangerous precident for other situations elsewhere in Canada. Some guy who was arrested for having child porn on his computer has been appealing and even winning in some cases, his right to own and make child porn for his own viewing.  There is a similar case in Eastern Canada where some guy is openly admitting to photographing and posing with naked children and the police can't arrest him and charge him with anything because he isn't "distributing" what he makes.  In my eyes it's still child exploitation and should be against the law. Now granted this involves "real" children, but as the above article I linked to states, that even if it involves only computer generated images and no actual real children, the message is the same thing... a child being exploited.

http://www.efc.ca/pages/media/national-post.16jan99.html

Hopefully that answers your questions :)

 

"It is good to see ourselves as others see us. Try as we may, we are never
able to know ourselves fully as we are, especially the evil side of us.
This we can do only if we are not angry with our critics but will take in good
heart whatever they might have to say." - Ghandi