A New Base Genome: Of Buff and Obese Norns

 After a continuous four days worth of constant tweaking and testing, I believe I've finally created a norn base genome I'm happy with. At first I figured I'd just talk about all the changes I made in one post, but there's one change I feel is worth giving its own post: the changes to the digestive system, or why unedited 2017 creatures have so much muscle tissue all the time.

First, a brief explanation about how the creature digestive system works in C3/DS. There's three nutrients a creature can be hungry for: starch, protein, and fat. When a creature eats something that gives it one of these nutrients, it's then converted into a matching short-term energy source: glucose for starch, amino acid for protein, and triglyceride for fat. If the creature doesn't need those short-term energy sources for anything else, they're converted into a matching long-term energy source: glycogen for glucose, muscle tissue for amino acid, and adipose tissue for triglyceride. These can then be converted back into short-term energy should the creature need it (e.g. when it's having trouble finding food).

However, there's a problem in vanilla creatures with the reaction that generates muscle tissue. It's reliant on another chemical called anabolic steroid (yes, it's named after what you're probably thinking of), which is supposed to be generated by a chemical emitter that fires based on "Muscle energy used." Which is to say it almost never fires at all. So vanilla creatures don't generate anabolic steroid and thus can't build up muscle tissue. Fortunately, the rest of the digestive system has enough redundancies that this isn't crippling for them and is likely to go unnoticed by the average player.

Nevertheless, it's a flaw that's been corrected in both the 2017 and TWB/TCB genomes. Both genomes made use of the originally-unused chemical Activase (something you might recognize from C1 and C2) by tying it to the stimulus genes associated with movement (e.g. pushing, grabbing objects, and walking around).

TWBs/TCBs generate minute amounts of Activase from these stims, and it's consumed in a chemical reaction that generates both anabolic steroid and body heat (chemical 110; used for a lot of things in the system that gives them their name). However, they aren't entirely reliant on this reaction to get anabolic steroid. Their version of the anabolic steroid emitter fires when their muscle tissue drops too low alongside hunger for protein, so even if they don't generate enough activase from physical activity they can still build muscle tissue.

In 2017 creatures, it's another story. Their version of the anabolic steroid emitter fires based on the amount of Activase in their system. To compensate, they generate more Activase from the physical action stims than TWBs/TCBs do. They also get Activase from two stimuli that TWBs/TCBs do not: eating and disappointment.

As it turns out, it's that latter stimulus that explains why they have an excess of muscle tissue. Disappointment is the stimulus that fires whenever a creature can't do something, e.g. eat an inedible agent or try to grab something that's out of reach, but tries to do it anyway. It's a stimulus that fires a lot. On top of that, 2017 creatures get a lot of Activase out of it, to the point that they might as well have an excess of it all the time.

2017 creatures also have a pair of reaction genes that has Activase consume glycogen and adipose tissue, also solving an issue vanilla creatures have where they build up an excess of adipose tissue. Coupled with the flood of Activase they get from the Disappointment stim, this explains why they get hungry for starch and fat quickly.

So the solution seems obvious: remove the Activase from the Disappointment stim. And indeed, I tried that...but quickly found that the actual action stimuli get triggered a lot less than you'd think, especially in cases where there's not much around to interact with (like in the Capillata Hub or the Bridge/Engineering on the Shee Ark), and when there's agents around they keep trying to interact with but can't.

So ultimately, they wind up not being able to build up muscle tissue consistently, effectively being the same as vanilla while also creating the opposite problem where they rarely get hungry for starch and fat but are constantly hungry for protein. But that's not even the worst problem here.

The CFF introduced a gene in the Mitochondrial Function organ (the organ responsible for the most vital reactions in a creature's system; you can think of it as the creature's heart) that damages it should adipose tissue get too high. In other words, they can have heart attacks. And in a 2017 creature that can't generate enough Activase to trigger the reaction that consumes adipose tissue constantly, the risk of a heart attack goes up dramatically.

At first I tried increasing the amount of Activase gained from the other stims to compensate for the loss of the Activase from Disappointment. If I was careful to have norns stay in rooms where there was a lot they could interact with it worked all right. However, this meant I had to be particular with what they tried interacting with, and ultimately I found this to go against what I wanted out of my base genome: to be adaptable and good even when not constantly monitored.

So instead of getting rid of the Activase from the Disappointment stim outright, I drastically reduced it. It's still not a perfect fix; the stim still fires a lot. But it's still less than default 2017 creatures, meaning that there are cases when they aren't generating Activase all the time and generally reaching an equilibrium of getting more hungry for starch and fat when doing things and getting more hungry for protein when not, and with much less risk of getting heart attacks when they're actively trying to do things.

I also thought about throwing this out the window and just copying the TWBs/TCBs' system because honestly they handled it a lot better, but I decided I wanted to maintain compatibility with default 2017 creatures as much as possible and thus working with the system 2017 creatures already had felt like the best option.

To summarize: Creatures get disappointed a lot; 2017 creatures get too much activity chemical from it by default, so they're buff all the time. But removing that lets them build up too much fat and makes them get heart attacks too easily, so the solution was to reduce the amount of activity chemical they get from being disappointed.

Next post will be the full breakdown of the changes I made from the default 2017 genome. Until then, folks.