In the notes for my last update, I talked about the new genetic system I'm using and said I would chase up the link to the thread, if anyone was interested. Tanja was and on the chance she wasn't the only one, I'm adding it here too.
So...Simmerville at The Sims Daily started this fantastic thread quite a while ago, talking about his/her (most simmers seem to be female but Simmerville has always used male avatars, so I think they might be a guy?) genetic system in TS3, used to decide whether a sim will have freckles, glasses and their level of hairiness. It's an interesting read.
If you're a member of N99, you can also read this thread, where I talk a bit about how I'm planning to adapt it to my own game. I'd never really thought about an actual system for this kind of thing before but I was immediately excited when I read Simmerville's thread!
It's almost a year later now (wow!) and I've been thinking about this a bit and deciding how I will implement it into my own game. I'm going to write this as if you've read Simmerville's original post in the thread I linked to, so go read that!
Glasses: I already had the vague idea that bad eyesight was something I wanted to be hereditary. Adrienne has glasses because I figured she inherited her poor eyesight from her dad, Owen, who also has glasses. I just decided to give her glasses and not give them to her brother Malcolm on a whim. He may end up with them now, but not until he's an elder (more on that later).
I am interpreting gg to mean "will never need glasses", Gg to mean "will need glasses at some stage" and GG to mean "will need glasses probably from day dot".
Freckles: In Sullivan, I have freckles running in the family with the Carmody clan (and by extension, the Collins - remember Anna was a Carmody before she got married). I had just been adding freckles to any fair-skinned kid of a freckled parent. That won't be how I do it any more. I've only worked out the genes for some of my families (I'm using Hook's Random Stuff for this) but I have done Jesse and Abigail's family. With this new system, ALL the kids should have had freckles. Jesse got FF for his freckle gene (or would that be genome?), because how could he not and Abigail rolled the same. There is no possible way for their kids to end up without freckles.
I am interpreting ff to mean "no freckles ever", Ff to mean "some freckles" (one freckle mask in CAS) and FF to mean "more freckly" (two or more freckle masks in CAS). FF is not necessarily going to look like tons of freckles on every sim. Brendan is FF, for instance, but the masks I chose for him were not overly freckly one.
Hairiness: Simmerville's hairiness gene affects male and female sims. For males, it decides whether they can grow a beard, whether they'll go bald, etc. and for females, it decides on how thick their hair is and whether they're likely to be able to grow their hair very long. In my game, I've decided the hairiness gene can be passed down by females but only males will be affected.
I am interpreting hh to mean "not very hairy" - they won't be able to grow anything thicker than light stubble and will probably go bald in middle age. I am interpreting Hh to be about average in terms of hairiness - he'll be able to grow a beard and will probably keep his hair at least until elderhood. I am interpreting HH as my very lucky sims. These guys will be able to grow nice, thick beards if they want to and will not go bald at all.
What this means for my sims' appearances: I'm not going to go around adding glasses to sims who've never had them, just because they've rolled GG. Glasses are a pretty big change to appearance and I don't want to throw everyone off! Instead, GG sims will get glasses on whatever their next age transition is.
Same with baldness. My hh boys will not suddenly go bald but they may indeed start to recede at their elder birthday.
Freckles, I have been adding as I go. Unless we're talking about Anna Collins-style freckles, they are usually a subtle addition to a sim's look. I don't know how many of you would have noticed the Lachance freckles if I hadn't pointed them out!
I will not be removing any features from my sims that contradict the genes I roll for them. This is mostly going to affect sims born from now on and sims who are too young to have had most of this affect them yet. So if one of my beardy guys rolls hh, he can keep his beard but he won't be able to pass any beardy genes onto his kids. No ff sims will lose any freckles they already have (though I don't think that's come up anyway, in the families I've done this for - all freckly sims had at least one F gene). No gg sims who wear glasses will lose their specs, though again, I don't think this has come up at all so far. My current sims will mostly keep their appearance as is, though it could change at birthdays. But things always change at birthdays, so hopefully that will not be too jarring!
Geez...this was going to be short! I am incapable of being concise. So to wrap it up, I just want to say again that I did not create this system. All credit for that is due to the awesome Simmerville. All I've done is adapt it for TS2 and for my own game.