How Hunger Works in Creatures 1
With my recent work on the Creatures 1 carrots and lemons, hunger and the Norn digestive system have been very interesting to me! I’ve learned a lot through CAOS, although there is an entire genetic side to the equation. While browsing through new posts around the Creatures community, I was inspired by Perichan’s question. If the following information seems useful, it would be very much appreciated if someone could include a link here! The mechanics behind hunger in Creatures 1 differ significantly between two sets of Norns. The standard breeds operate on a fairly simple system that results in hunger increasing rather quickly. The Life Kit breeds, such as the Forest Norns, use a floating emitter and receptor.
What does it all mean? This is one of those exciting instances where biology and genetics really jump out of Creatures! Two Norns can have the exact same diet, yet experience hunger in completely different ways. It might be worth reading a description of how a floating emitter-receptor pair works at the Creatures Developer Resource. To keep things simple, though, the pair can be understood as something that operates on its own, without the need for a brain lobe. In essence, these two genes are constantly “floating” in a Norn’s system.
First, we can examine the standard Norn. Note how hunger increased very shortly after starch reached zero. Glucose and glycogen are locked together, which is true for all non-mutated Norns: Glucose can be converted into glycogen, and glycogen can be converted into glucose. Where does a Norn get this nutrition? Starch! Starch is the building block of the digestive system, and it can be found in all standard foods. Starch is converted in glucose through a chemical reaction, and is used up in the process. So a Norn needs to eat in order to gain starch. Hunger is the mechanism that tells a Norns to seek out food and starch. Decreasing hunger rewards a Norn, which should teach him or her that eating is a good thing! Yet what about the rate at which hunger increases? Let’s take a look at the genetics!
Receptors
Chemical receptors define parameters for a certain chemical. When these parameters are met, an element in the Creature is affected. These genes can increase drives, define life stages, control fertility, and more.
46 Emb B MutDupCut Creature, Drive Levels Hunger, chem=Hunger, thresh=0, nom=0, gain=255, features=Analogue
Reactions
Chemical reactions define rules for individual chemicals and chemical combinations. These genes can also state the rules for how chemicals are used up, and each reaction has a defined half-life to determine how often it occurs.
59 Emb B MutDupCut 1*Hunger+ => 1*Hunger + 1*Punishment; half-life = 8
73 Emb B MutDupCut 1*Hunger- + 1*Hunger => 1*Reward; half-life = 8
142 Emb B MutDup 1*Starch => 2*Glucose; half-life = 64
144 Emb B MutDup 3*Glucose => 1*Glycogen + 1*Hunger-; half-life = 56
145 Emb B MutDup 1*Glycogen => 3*Glucose + 1*Hunger; half-life = 64
146 Emb B MutDup 1*Glucose + 2*Hexokinase => 4*CO2; half-life = 24
Note that not every digestive gene has been included, but this should paint a fairly clear picture! Hunger can be tied directly into a falling level of glucose. The very last gene includes a chemical called hexokinase, which is fancy talk for when a Norn moves around. One who is at rest is producing little to no hexokinase, while one who is running about is producing a large amount. This is where glucose gets used up quite readily. If starch is present, it produces glucose, which can then be used up. When starch is not present, though, glucose will start to fall, which then triggers the Norn’s body to convert glycogen into glucose. That right there produces the hunger chemical, which is then understood as the hunger drive. The short version: Without starch, a Norn’s body converts glycogen into glucose, thereby raising hunger. The reason for this is because glycogen is a long-term energy store, and depleting it is supposed to trigger a Norn to find food to replenish it through starch and, eventually, more glucose.
In a Life Kit Norn, one can see the difference in hunger immediately! I actually started counting how much longer it would take for hunger to rise, until it dawned on me that this was a genetic issue! Without needing to go into too much detail, the Life Kit Norns have two very big differences: Hunger is tied to glycogen, not glucose, and converting between glucose and glycogen does not affect hunger. The following genetics should look pretty similar, but take note of the differences! In short, hunger is tied into the floating receptor-emitter pair, and only rises when glycogen begins to fall. In my own experience, Life Kit Norns are typically much happier and require less food. This doesn’t mean that they’re prone to not eating, though! They still get rewarded for eating, even when they’re not hungry.
Receptors
Chemical receptors define parameters for a certain chemical. When these parameters are met, an element in the Creature is affected. These genes can increase drives, define life stages, control fertility, and more.
46 Emb B MutDupCut Creature, Drive Levels Hunger, chem=Hunger, thresh=0, nom=0, gain=255, features=Analogue
324 Emb B Creature, Circulatory, floating chem 2, chem=Glycogen, thresh=0, nom=0, gain=255, features=Analogue
Emitters
Chemical emitters define specific conditions within a Creature in order to affect chemicals. Some examples include experiencing stress from excessive drives, becoming cold due to environmental conditions, and more.
325 Emb B MutDup Creature, Circulatory, floating chem 2, chem=Hunger, thresh=0, samp=5, gain=2, features=Inverted Analogue
Reactions
Chemical reactions define rules for individual chemicals and chemical combinations. These genes can also state the rules for how chemicals are used up, and each reaction has a defined half-life to determine how often it occurs.
59 Emb B MutDupCut 1*Hunger+ => 1*Hunger; half-life = 8
73 Emb B MutDupCut 1*Hunger- + 1*Hunger => 1*Reward; half-life = 8
142 Emb B MutDup 1*Starch => 2*Glucose + 1*Hunger-; half-life = 64
144 Emb B MutDup 3*Glucose => 1*Glycogen; half-life = 56
145 Emb B MutDup 1*Glycogen => 3*Glucose; half-life = 64
146 Emb B MutDup 1*Glucose + 2*Hexokinase => 4*CO2 + 8*Activase; half-life = 24
As a recap, why do these two types of Norns experience hunger so drastically? Two reasons:
- Standard Norns tie hunger into glucose / Life Kit Norns tie hunger into glycogen via a floating emitter-receptor pair
- Standard Norns have an increase in hunger when converting glycogen into glucose / Life Kit Norns are unaffected
Hopefully this explanation shows how hunger differs in Creatures 1 based on the breed! I would be happy to go into more detail, or answer any other questions on the subject. I think one of the reasons why C1 Norns can be so miserable is based on unnecessarily high hunger levels. When possible, I recommend using the updated Life Kit Norn genome. Just keep in mind that mixing these two can have odd consequences: If only one part of the floating receptor-emitter pair is inherited, the resulting Norn may never experience hunger, and might never know when to eat. Good luck!
First Two Images Credited to Gameware Europe
Wow, actually stumbled upon this before anyone could point me this way. xDD Thought it sounded helpful, but I was surprised to see my own username!
Thank you so much for going through all of this! You clearly have a much better grasp of the whole “creatures” concept than I do, and I can honestly say I’m impressed. As it is, I feel like I still have just a rough understanding of the problem, but I think this did help me a bit!
So if you don’t mind my asking, just to clear this up…the problem is that when the standard norns get hungry, they eat starch, which converts into glycogen, and the process of converting the glycogen into glucose makes them hungry? So pretty much eating the natural food of the game makes them hungry?
Would that mean if I were able to find a COB or something that gave them more glucose, or glucose instead of starch, that it might keep them filled up more?
I’m so sorry for all the questions, but I really do want to understand this… x_x Again though, thank you so much already for looking into my topic. It’s nice to know that there is an actual reason, and that I’m not completely crazy. xD
I’m glad I could provide some help! And no need to apologize for asking questions! That’s the best way to learn and understand more about Creatures. There are some complex processes at work in the background, and learning more about them can be lots of fun!
Starch actually is converted into glucose, which is then converted into glycogen over time. Starch in and of itself is a good thing: It’s the building block of nutrition, and is where all eating should begin. Note that using COBs that contain glucose or glycogen end up bypassing some of these chemical conversions, and don’t actually teach a Norn to eat properly. The real problem is that starch is used up rapidly in a Norn, so eating constantly is the only way to keep hunger at bay. A quick note that the updated carrots and lemons I mentioned fix a lot of issues with the food items, which taught Norns how NOT to eat. Older Norns were prone to “forgetting” how to eat, simply because the food items didn’t function correctly. I’ve got other fixes on the way for the honey and cheese, but those two should make a big difference in the garden area!
Even when a Norn’s glucose is maxed out, as shown in these two graphs, the chemical reaction to convert starch into glucose still occurs. The standard Norn genome had a few oddities with it, and this is one important issue! I recommend using the Life Kit genome whenever possible. It’s actually pretty easy to use the Genetics Kit to load the Life Kit genome and change the appearance genes. That way, you can have a Banana Norn who uses the updated genes! That’s something I would be happy to walk through in a quick tutorial, and/or provide a download. Just let me know!
I hope this continues to help you understand things! Sometimes I ramble on and on, making the whole “easy to understand” concept not so apparent. But please feel free to ask any more questions! I love talking about all of the genetics and biochemistry behind Creatures!
I delved into this same issue when I created the Perfecio Norns a little while ago.
You’ll have to forgive me, it’s been a while since I created them and I’m bone tired from being a little sick (darn man flu), so your post is somewhat going in one ear and out the other.
I shall return to it in the near future and see if we came to the same conclusion. In the mean time, you can grab the Perfecio breed from The Creatures Arch (sorry for the shameless plug).
And there’s a stack of blog posts I did as I was creating the breed which may be of interest.
Shameless plugs are encouraged! I remember following along with some of your posts regarding the Perfecio Norns, yet I think it was a little before the time when I really started to understand it all. I’ll definitely have to take another look when I have some time! Hopefully you’ll return to see if we did come to the same conclusion about hunger and how it’s not all that great in some breeds.
Interesting stuff… the standard C2 genomes also had hunger that worked much like the life kit norns… based on glycogen levels. I wonder why they moved away from having hunger based on the nutrition in their bodies in C3… For some reason C3 creatures just generate their hunger drives constantly and none of them actually look at their nutrition stores or even any of the nutrition conversion reactions.
I haven’t even attempted to understand the C3/DS Norns and their hunger, but I think you explained it perfectly in a nutshell! I always thought they had odd eating habits… Many just eat everything in sight without acting very intelligently. I know C1 Norns can eat a bunch of food at once, yet they seem to know when to stop! Interesting that there’s another case for why C3/DS Norns might have been complex genetics and biochemistry, but they might not actually do much of anything. Thanks for that quick summary of helpful information!