This may not be the best forum for this question, but I know a lot of you have dabbled in the field of general AI for games so here it is.
I'm doing the cliche population evolution of creatures in a simulated ecosystem (with some cool irrelevant twists) where each creature is its own neural network. Specifically, I'm using the NEAT algorithm to evolve creature brains over generations.
My problem is that I can't figure out what to feed as input to the creature neural networks. I haven't found any relevant literature on it either.
The world right now is composed of prey/predator creatures and grass for the prey to eat. I want all creatures to see all three objects (prey, predators, and grass). The other important point is that the populations are not fixed. Prey can become endangered, grass can become limited, etc.
Initially I was going to have a list of all objects as relative positional vectors within a radius of a given creature as input, but variable sized inputs are basically a no go for neural networks. My second idea was just show everything in the scene (even if it may be a sensory overload), and when an object dies just replace it with a -1 hot vector. But that would just confuse the ANN.
I'm out of ideas and flailing in the water. Any thoughts are appreciated.