Show HN: Watch a neural net learn to play Snake

(ppo.gradexp.xyz)

91 points | by c1b 1 day ago

15 comments

  • joshka 1 minute ago
    A previous similar idea running as a Ratatui based TUI: https://github.com/bones-ai/rust-snake-ai-ratatui
    • jesuo 21 minutes 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
      • ziofill 24 minutes 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 16 minutes ago
          But if not the snake could go into an infinite loop, never growing, never eating.
        • simedw 5 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 3 hours ago
            It seems to be something related the moving average calculation. So it is just a glitch on the chart.
          • snats 2 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 4 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 2 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 3 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 1 hour ago
                  That's cool, i did exactly the same few years ago
                  • beardsciences 4 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 5 hours ago
                      More details and implementation notes please?
                    • LowLevelKernel 3 hours ago
                      Link to repo?
                      • bozhark 2 hours ago
                        Crashed
                        • jmclnx 3 hours ago
                          > WebGPU not available in this browser

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

                          • NoboruWataya 2 hours ago
                            I got this in Firefox on Linux, just had to enable WebGPU in about:config (`dom.webgpu.enabled` = true).
                            • jmclnx 2 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 3 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
                            • th1nhng0 4 hours ago
                              cool project
                              • austinthetaco 4 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.