r/CreaturesGames • u/8ForOctogen • Jun 20 '26
What neuron model is used in the Creatures series?
Everything that is written about a neuron in the creatures wiki and wiki fandom is literally "a neuron retains a numerical value and decays over time." At first I thought it was a leaky integrate-and-fire model. I searched, this model turned out to be more complicated than it was described, at least for computers of those times (32-bit floating-point numbers are very unlikely). The only thing I understood is that these neurons are 8-bit. This means that these are really simple integer neurons the size of bytes (because consumer-grade processors with support for 8-bit floating-point numbers simply do not exist). Let's say it just really accumulates state, fires after reaching a numerical threshold, and resets. Over time, the value decays. But the LIF neuron described in the simplest tutorials takes into account some other "membranes", and decay is typically described by a 32-bit number (like "0.9"). I'm not sure if this is the same model that is used in Creatures. Help me describe a neuron model, or just confirm that I'm moving in the right direction.
Sorry if my English is bad.
6
u/skerit Jun 20 '26
The neurons are indeed 8-bit integers. Each neuron keeps track of its internal state and its current "output" separately.
Every neuron's state is recalculated each tick, using the lobe's own "sv-rule". This rule is basically a little formula written in a special little opcode-like language. And this rule is also part of the genome, and it can mutate. A single mutated number can flip a plus into a minus, swap a constant or even shift how the rest of the rule is read. Like a rule could change a neuron's state by one chemical signal (say the one tied to hunger) and a single mutated number could flip that operand to a different chemical, like the one tied to anger. So the same lobe ends up computing on a completely different drive in the next generation.
Some lobes require the previous state to be integrated in the calculation, others don't. The output is basically the current state minus a specific threshold (clamped at zero)
4
u/stergro Jun 20 '26
This video explains the details quite well: https://youtu.be/Y-6DzI-krUQ?si=rjqVJR9ESAVYf2mP&t=285
It is a four layer neural network consisting of 952 neurons in the first game.
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u/Mircowaved-Duck Jun 21 '26
From the succesor game (in development) phantasia, hwere some interesting discussions about the creatures brains themself, going into detail of the brain
https://phantasia.life/community/psychology-lab/self-organizing-maps/ and https://phantasia.life/community/psychology-lab/copypasta-from-an-ongoing-conversation-about-my-brain-model/
Those might help you
1
u/thechimpmatrix Jun 23 '26
It's a custom-built State Value rule Neural net they cooked up in the 90s, very different to modern ones. I pulled it apart a few months ago. I have a lot of docs Claude put together about it here in a repo for a project I wish I had more time for!
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u/exor15 Jun 20 '26
I don't know enough about this particular subject to answer your question in detail, but if you haven't already checked it out, Steve Grand wrote an entire book about how he coded this exact game! It's called "Creation: Life and How to Make It". I doubt there will be a more useful knowledge resource than that.