Show HN: Watch a neural net learn to play Snake

(ppo.gradexp.xyz)

98 points | by c1b a day ago ago

22 comments

  • joshka 35 minutes ago

    A previous similar idea running as a Ratatui based TUI: https://github.com/bones-ai/rust-snake-ai-ratatui

  • jesuo an hour ago

    Poorly programmed, it doesn't learn from its mistakes, the games get stuck in a loop because the snake doesn't capture a piece but the piece remains and there's a gap, constantly moving the snake along the same path with negative scores in an infinite loop leaving an unaltered yin and yang ;) there's a repetitive pattern in these infinite games between the position of the gap and the piece

    • spectre9 7 minutes ago

      Did you let it train? This doesn’t happen for me

  • simedw 6 hours ago

    Cool project!

    I noticed that if you go from training to watch and then back, the training temporarily drop significantly in score.

    • bguberfain 4 hours ago

      It seems to be something related the moving average calculation. So it is just a glitch on the chart.

  • ziofill an hour ago

    I noticed snake gets penalized for not getting to the apple early, is that what you really want? Snake is about how long it gets not about the balance between length and wall clock time

    • foo12bar an hour ago

      But if not the snake could go into an infinite loop, never growing, never eating.

  • snats 3 hours ago

    did a pretty similar thing last month for the text rendering library last month.

    trained and made a viz for the model and then made it displace text.

    should probably do a proper write-up:https://x.com/i/status/2038367016969724259

  • ldoughty 5 hours ago

    Really cool! But right as it was nearing 4,000, it seems to have corrupted itself and no longer got any scores above 0. Not sure if that's a code bug or a neural net issue.

    avg500 -4.6 last 500 episodes

    peak 3959.3 best window

    roll/s 20.68 20-step avg

    progress 4388 562749 episodes

    • c1b 3 hours ago

      Yes it just collapses eventually — never stabilizes. The training process is flawed, I suspect it has to do with the fact that some weights blow up over time, you can see in “weights” tab.

      But at around 4K avg score you should see it solve the env almost every time.

      Just a demo :) optimized for speed over stability.

      Reward structure: Step: -1 Dot: +100 Win: +1000 so ~4k is max theoretical score on 6x6.

    • r3trohack3r 4 hours ago

      I think I noticed it reach “end game.” The snake reaches a point where, if it gets any longer, it is out of squares and hits its own tail. So it finds the route through the squares that it can infinitely loop, never eats the ball, and score starts dropping and goes negative.

  • mavdol04 2 hours ago

    That's cool, i did exactly the same few years ago

  • beardsciences 5 hours ago

    My average eventually made it to about 3900, and then stagnated between 3600-3900. I'm curious if this is universal behavior or not. I'm up to about 5k steps.

  • neduma 6 hours ago

    More details and implementation notes please?

  • LowLevelKernel 4 hours ago

    Link to repo?

  • bozhark 3 hours ago

    Crashed

  • th1nhng0 5 hours ago

    cool project

  • jmclnx 4 hours ago

    > WebGPU not available in this browser

    Looks like this is for Linux and Windows, on NetBSD I get this issue :(

    • NoboruWataya 3 hours ago

      I got this in Firefox on Linux, just had to enable WebGPU in about:config (`dom.webgpu.enabled` = true).

      • jmclnx 3 hours ago

        Did not know that existed, I enabled it but no luck. Must be a NetBSD thing based upon this new message:

        > WebGPU is not yet available in Release or late Beta builds.

    • redshiftza 4 hours ago

      If you are using brave (which i assume also applies to chrome) , there is a menu at brave://flags , you can enable unsafe web GPU from there

  • austinthetaco 5 hours ago

    my training on a 10x10 just randomly broke. i got to like 3600 then the graph went flat, the viewer on the left just showed it constantly restarting the game, and the scores in the negative. my average is now -10.