So, I know this has been an ongoing problem that zombies seem to like to go through walls... I was just wondering how tough it would be to fix an issue like that. I recently learned about some AI path-finding for a new game that I am helping to create, and so I learned all about nodes and search functions used for AI to be able to maneuver around objects. My question is this: how tough would it be to implement a node system for the zombies to follow players so that they wont go through the walls? After doing that, it seems like it would be simple to just make the walls non-collectible with the zombie. Now, I did just recently research this AI stuff, so I am by no means an expert, but why isn't this problem fixed??? If the problem is much more complex than this, please explain it to me.