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My friend found this link, which is really cool to look at. It is using genetic algorithm to tune the traits of the car.
The attributes of the car are:
Shapes of the car body
Location of the wheel
Size of the wheel
The body of the car is made up with triangles, and I imagine the algorithm looks for the best combination of triangles of certain sizes.
There are many ways to look for the best combination of these attributes, one silly way is to simply go through all possible combinations. However, this is impractical because there are so many different combinations. What genetic algorithm does is sample a generation of cars, rank them by how far they can travel, and let the high-ranking cars exchange traits (mating) to form the next generation, then repeat. So all in all, genetic algorithm is nothing special or mystical, it is merely a way of finding a good combination of traits in a space of huge number of combinations. So you can call genetic algorithm a kind of "heuristic guided search".
I'll try to explain "mutation rate" here, this is my understanding:
At each generation's end, we're at the verge of developing the next generation. What can we do? Well, we know so far we'd like to take some top-ranking cars, and cross-over their traits. But, this has the danger of getting stuck. For instance, suppose in an unlikely event all of your cars start off identical to each other, then by crossing-over their traits, you actually gets nowhere. What the mutation rate is, then, it means that after the crossing-over, we get a trait for our new car. We then keep 95% of those traits, and replace 5% with something completely random. An intuitive way to think of it is this: You are 50% like your mother and 45% like your father and 5% like yourself, completely independent of your mother and father. Another way to look at it is mutation is the opposite of retention, the more mutation, the more likely you are going to discover new shapes of cars, and more likely you are going to FORGET what has worked well before. A 0% mutation will stop evolution altogether, by not exploring the unknown, whereas a 100% mutation is going to be completely chaotic, by not remembering what it has learned in the past.
I ran the webpage on my computer over 2 days, just to see how far it can get, it seems to hit a plateau of performance after awhile, here's a screenshot:
![[image loading]](http://imgur.com/ygLEJ.png)
Here's the link to the webpage:
http://megaswf.com/serve/102223/
If you follow the first few generations, these car evolve really freaking fast, good "car-like" robots start to form around generation 8 or so for me, alongside with many retard shape cars 
So run the webpage, and shere some screenshots!!!
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That is so cool, I'd love to see the code of this. But I don't really understand when the "test run" of a car stops. If they fall over it's ok to do a new run but sometimes it starts a new round for no reason.
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I think it starts a new round when it reaches a new best score or so. This is so cool I can't believe how fast it evolved to a "typical" car shape
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I was laughing my ass off at some of the terrible cars that came out of this thing, and my dad came in my room wondering what was so funny. Was a bit difficult to explain,
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On January 24 2011 09:15 gogogadgetflow wrote:
I think it starts a new round when it reaches a new best score or so. This is so cool I can't believe how fast it evolved to a "typical" car shape
There are glitches of that program I think. It sometimes stop the test prematurely. It doesn't stop it when it reaches a new score because logically it's good to give the code more time to run so to attain an even higher score.
But yeah it evolves pretty fast haha
actually take it back. It stops as soon as it reach some high-score, i.e. we know for sure it is the best so far.
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I feel like I'm watching evolution fail dramatically. lol Still interesting regardless.
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I've been watching it non stop trying to catch the one baller car that goes like 400, but so far I've seen a lot of unicycles flipping over haha
Edit - yeah like the post under me says, the ones that evolve an arch to prevent getting stuck and a little thing on the back to stop them from flipping back are kicking ass. this is awesome :D
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The funny thing is that these cars seem to develop a shape that prevents them from falling over.
Edit: Like this one ![[image loading]](http://i.imgur.com/ZUEgv.jpg)
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the cause of the plateau on my box was a hill with a pinacle at distance 180; the cars needed a short wheelbase to get over the hill but a large wheel base to get there.
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So, what does the mutation rate actually do?
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Any idea what the mutation rate does?
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On January 24 2011 09:36 LittLeD wrote:
So, what does the mutation rate actually do?
it's a measure of how much random changes in the car design are put in between generations. It may even be the setting of how much the settings of each car are 'jumbled up' between the cars in the genetic algorithm.
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I'd guess it changes how much or how fast the different parts are changed. How intense they mutate, if you will.
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It doenst always evolve the same way. I have one window where it gets consistent ~175 after 6 generations and in the other one it still does retarded shit in generation 25.
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On January 24 2011 09:36 LittLeD wrote:
So, what does the mutation rate actually do?
Probably changes how fast the parameters changes and how wildly they change.
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On January 24 2011 09:40 betaben wrote:Show nested quote +On January 24 2011 09:36 LittLeD wrote:
So, what does the mutation rate actually do? it's a measure of how much random changes in the car design are put in between generations. It may even be the setting of how much the settings of each car are 'jumbled up' between the cars in the genetic algorithm.
Which means that a higher mutation rate yields more random looking results but gives the evolution a chance to create a car that deviates from the properties of its ancestors.
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Mine just went from 90+ to less than 10 in about 4 generations. Seems like it began to regress through some bad traits that just kept popping up. I guess my cars needed an ice age to reset things.
Edit: This was on 100% mutation rate.
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On January 24 2011 09:42 uNiGNoRe wrote:Show nested quote +On January 24 2011 09:40 betaben wrote:On January 24 2011 09:36 LittLeD wrote:
So, what does the mutation rate actually do? it's a measure of how much random changes in the car design are put in between generations. It may even be the setting of how much the settings of each car are 'jumbled up' between the cars in the genetic algorithm. Which means that a higher mutation rate yields more random looking results but gives the evolution a chance to create a car that deviates from the properties of its ancestors.
Jeah, if you set mutation to 0 and you have retard cars, you keep getting retard cars. That also works the other way around. So if you set it higher you have more chance of getting better/worser cars
Note: the chance of getting better cars is a bit higher becouse that's what the game selects on but with a higher mutation rate you also get a greater chance of getting worse cars
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i do not understand the graphic and color o the car is there a meaning ?
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EPT
