There's already a way to get it for free. The entire source code is available here: https://github.com/keiwando/evolution, so you can download it and download Unity (also for free) and build the windows version yourself.
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It sounds like you downloaded the free Linux build instead of the Windows build. I think the itch.io download interface might be a bit confusing but you only get download links to the Windows and macOS applications if you pay $2 (or more).
The downloaded file is a ZIP file of a folder. You need to unzip that somewhere on your PC and then inside of the folder is an Evolution.exe file, which you should be able to double click in order to start it. Let me know if that doesn't work and if so, what happens instead of Evolution launching.
I haven't used the itch.io launcher myself but I suppose that would simplify all of this to just downloading Evolution through the launcher and then clicking "Launch" in there. You could also try that.
The number of creatures is not decreasing, but they are slowly converging towards the exact same behaviour, so it looks like there are fewer individuals (since they are perfectly overlapping each other). I have seen this happen with certain simulation settings, so try changing the mutation rate, mutation algorithm and recombination algorithm. Are you using "Chunk" as the mutation algorithm by any chance?
Yes, you can export your own creature designs and saved simulations on all platforms except for the browser version. There is an "Export" button when you open the list of saved creates / simulations.
Unfortunately, it turns out that in the vast majority of cases the noticeable performance drops happen because of Unity's physics system, which is single-threaded on the CPU and out of my control.
There are librarians in some of the rooms. They are completely harmless and are also just trying to understand the meaning of the books. You can click on them and they will tell you what they know, though most of it is as much gibberish as you can find in the books yourself.
If you mean that you want to be able to edit the creature design after backing out of a simulation that you loaded from a file, that is currently not possible, but I already have it on my list of things to add with a future update.
You can use the "Export" button in the save file selection window to save them to an arbitrary location.
If you just want to copy the entire folder you can find it at
or if you use a Mac
~/Library/Application Support/Keiwan Donyagard/Evolution
There should be two folders there: "EvolutionSaves" and "CreatureSaves"
I've sent an e-mail to support about another payout-related issue 35 days ago and a follow-up a week ago and haven't received any response other than the automatic "Request received" confirmation. At this point any response, whether it's a "we don't know when this will be fixed" or "sorry, we have a lot of support tickets queued up and we'll probably get to yours within the next two weeks " would be significantly better than nothing.
I'll gladly cut them some slack given their small team size and the current state of the world but this complete lack of communication for so long is quite frustrating.
The same piece of text can be found in multiple places in the library. The search menu randomly picks one of these locations each time you hit search.
You can verify that the text was actually in the book that you searched for before you searched for it by remembering the exact location of the page (hex, wall, shelf, book and page number). You can go to this location at any point in time, in the browser version or the offline version on any machine and will find the text that you searched for.
As long as the mutation rate is greater than zero, there is always the possibility that a creatures manages to mutate its way out of a local maximum. I haven't seen that happen myself, but to be fair, the majority of my time on this project was spent implementing it and not experimenting with long-running simulations.
What I would recommend is to try to play around with different selection, recombination and mutation algorithms and to increase the mutation rate when the fitness starts to stagnate. The settings that lead to the most randomized simulation behaviour (which can be exactly what you need if you're stuck in a local maximum) are
uniform recombination and
with a mutation rate of 100%.
As far as the network size is concerned, I have seen some very interesting results with networks about the size that you have chosen. Sometimes with even more intermediate nodes (but not with more layers). I haven't seen too many successful simulation results with very deep networks. You might get lucky and immediately start off with one that works really well, but it's a lot more unlikely than with smaller networks.
The network inputs include the average rotation of all bones which can give the creature some sense of rotation. Additionally, the creatures cast rays into the world in order to learn about the distance from their surroundings. Some of these rays have a fixed direction (e.g. up and forward) but one of them is controlled by a neural network output of the creature itself. It could therefore also use the information it gets from these rays in order to determine its current orientation in space.
Is it possible to disable some of the dashboard notifications? Specifically, I would like to disable notifications about new followers and builds that have completed processing.
I know about the e-mail notification settings but wasn't able to find anything regarding dashboard notifications.
You must have missed this sign, it's right by the entrance.
Jokes aside, you're not supposed to jump to the other floors - it ruins the illusion. I guess I forgot to prevent you from being able to do that. At the current rate of updates for this app, I'd say this is going to be fixed in about 2 years.
Thanks for letting me know about this issue, though!
I've been in sporadic contact with Jonathan since 2015. I wasn't just loading content from his website without his permission :)
In fact, a very early release of this 3D library used to be hosted on libraryofbabel.info http://libraryofbabel.info/lob3d.html. I'm guessing that it has gotten lost during the recent time of technical difficulties that the site went through (same as with the old forum).
With the most recent update I added my own algorithm for generating the pages in the library instead of loading them from libraryofbabel.info. This makes the apps work completely offline and also allows me to host a browser version here on itch.io without having to deal with cross-origin resource sharing issues. It also makes the pages show up a lot faster.
The pages are going to be in different locations since Jonathan's implementation of libraryofbabel.info is not publicly available and I would need to know all of the details and exact parameters that he uses in order for me to make the pages show up in the exact same locations. Both algorithms are mostly based on the same concepts, though.
You can find my implementation here: