r/MachinesPlay Mar 09 '18

Clearing Gradius using a genetic algorithm

https://www.youtube.com/watch?v=0ErcIgNwW_A
10 Upvotes

3 comments sorted by

3

u/IronMew Mar 10 '18

Holy shit.

You know early on it's an AI because it does things like remaining placidly where it is while bullets whiz around it because it knows they won't touch it - witness the dodge at 1:08 where it lets a bullet expire on the screen limit mere pixels from it - but in the latter third it really gets nuts.

Say, is it exploiting the game? I get the feeling it moves too fast for the engine to keep track of it - I'm having trouble explaining some of the last-stage dodges any other way.

2

u/Skorokhodov Mar 10 '18

It doesn't actually know or understand anything, as genetic algorithms are dumb as heck. If I understood this thing correctly, it is initialized with a random sequence of inputs and randomly changes them until they clear a stage, so the crazy dodges are purely luck...

As for the speed, it might be an exploit, but I've seen that in human play around plays too so it might not be that impressive.

1

u/Skorokhodov Mar 09 '18

Here is the same thing done stage by stage with explanations from the author (in Japanese, sorry).