I’ve been trying it with the mutation rate set to 0. They still make significant progress, up to over 200.
I’ve decided that the most important factor is how jagged the track gets and if it has really steep sections (OK, that’s two factors).
Great. I’ve been playing around with this for 2 days now. For anyone that didn’t notice, it’s always the same track that you are on.
A zero mutation rate, in about 12 rounds, gives me a line of cars that are all very similar, and will all top out at one of 3 hurdles in the 190-230 range. At that point there doesn’t seem to be enough genetic variation left, to allow the changes needed to overcome the newest obstical. But while this breeds out the superstars, it does drastically improve the average travelled (average of all 20 cars in a generation). As soon as you reintroduce mutation, the average takes a nose dive, and usually you start seeing superstar cars appear again.
I’ve been unable to get the timing right, but I’m working on an idea. Run the cars with a 10%ish mutation rate, until I get a generation with a couple of very good cars in it, than clamp down the mutation to 0, and see if I can force those car strains to take over the population. Once that happens, open mutation back up, and see if I can move on from there.
Hmm, sounds like of like a dog breeding plan.
I wouldn’t count on this working. Genetic algorithms are notorious for getting caught in local optima and never breaking out.
To clarify, always the same track for each generation of a set of runs, but if you start over it’s a new track.
The track for my current case has a very steep segment right at 210. Nothings got past it yet.
I’ve had this running for 2 days with a mutation rate of 2%. I’m on generation 96 right now. My cars have all evolved a long, purple spike on top of them that allows them to get past a certain steep section of the track by flipping over backwards, doing a 360 in the air, and then landing upright and continuing onwards. At least 7 or 8 cars in every generation perform this trick. The cars that are able to do this go twice as far as the ones that don’t.
New version up: http://www.boxcar2d.com/
It seems that this version only works smoothly if I keep jiggling my mouse around? Is my system bugged up, or does anybody else have similar problems?
Works fine for me.
By the way, it also now has a FAQ and “About” to clarify questions like those in this thread about how it works.
Edit: a yet even newer version is up, which allows for multiple wheels.