Evolution

Create creatures and let them evolve to see how they master various tasks. · By Keiwan

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the fastest creature thing is pretty broken

A topic by Squidmollusk created Aug 25, 2018 Views: 1,522 Replies: 11

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Squidmollusk6 years ago (1 edit)

i know that the developer definitely knows that this is a problem but i noticed that on generation 2531 my fastest creature was at 13.35 m/s but in gen 2549 the fastest was 12.68 m/s. So there's definitely a glitch there. also i have v 2.0.1 of the simulation/program/game if that affects anything

Squidmollusk6 years ago

also how long is the map? i run each generation with 5 batches, 15 seconds, and in the fastest creature of previous generation simulation, the creature runs off the edge before all 5 batches are done

Squidmollusk6 years ago

i've been replaying the same generation over and over and the fastest creature is always slower than the previous fastest creature for some reason. I don't know why. it's weird

Squidmollusk6 years ago (4 edits)

after using the arrows on the top left in the best creature screen to look through past generations, i've discovered that the fastest creature has been bouncing back and forth from avg speeds of about 12 m/s to about 13 m/s and hasn't ever reached anything higher. i don't know how the fastest creature for one generation could possibly be slower than the previous because i have the "keep fastest creature for next gen" on. it's really weird. I don't think my "Muscle Beasts" can evolve any further. They should be but it's just not working right

edit: after looking through past generations i discovered it has been going from about 11 m/s to 13 m/s for hundreds of generations

edit: it actually got to 14 m/s at some points

edit: ok so they've been like that for over 2000 generations lol

KeiwanDeveloper6 years ago

https://itch.io/t/143627/fitness-drops-between-generations

It's most likely due to Unity's physics system not being deterministic and consistent between different simulation runs.

Squidmollusk6 years ago

ok that makes sense but it's odd how the speed never gets higher than a certain point. also, if you wanted to know, the creature has reached 100% fitness and has been like that for a while

Squidmollusk6 years ago

ok so the first one with fitness level 100% was the best of generation 22

CarlosFernandez6 years ago

This is actually a very common problem in machine learning, including neural networks. I think what's happening here is that for your neural network's current weights, an optimal (or close to optimal) combination of weights has been reached. So in the next generation, when the weight's values are slightly "mutated" and then recombined, the optimal combination of weights for your neural network is being "overshot."

One way of thinking of this is imagine you're trying to find the lowest point in a landscape. At 13.35, you've just about gotten to the lowest point possible (or at least very close to it). So each generation after that you're stepping over, or "overshooting" that minimum point.

What you could do, to get even closer to that minimum point (or in this case, optimum fitness), is lower the mutation rate. That'll get you faster speeds, but downside of this is that getting to those speeds will typically take longer.

Squidmollusk6 years ago

ok thanks. The mutation rate was at 75% now i shall lower it to 25%

Squidmollusk6 years ago (1 edit)

ok the mutation rate has been lowered to 5%... Speed is now 11 and staying there

Squidmollusk6 years ago

gonna try 100% mutation rate.

Squidmollusk6 years ago

... and i thought 13m/sec was high. I looked through every single generation (took a couple hours) and wrote down the generation and speed of every top creature with a speed of at least 14 m/s. I got at least a hundred, and the earliest one came at only gen 54. I even had a few in the 15's. Fastest one ever had 19.46 m/s, gen 1189.

And i thought 13 was fast