AI Behavior Trees

[coreys]

I have to agree with WD here 100%. (Also, I prefer JSON but still haven't gotten around to finishing a JSON parser for GS2...)

Anyways, new release!

Behavior Tree Version 1.1
I have added the ability to load behavior trees from a simple file format.

PHP Code:

this.behavior = new TStaticVar();
this.behavior.join("ai-behaviortree");
this.behavior.loadFromFile("behavior_tree_name", this); 


This will load a behavior tree from a "behaviors/behavior_tree_name.txt" dynamically. Make sure that your npc-server has rights to this. The comments in the script should explain the further details.

Here's what the example script in the first post looks like in file format:

PHP Code:

rootSelector
  leaf search %this
    decorator filter %this,state,idle
    getParent
  sequence
    decorator filter %this,state,chase
    leaf findPath %target
      getParent
    leaf move %this
      decorator loop %path_size
      getParent
    getParent
  sequence
    decorator filter %this,state,attack
    leaf attack %this
      getParent
    macro pause 0.5
    getParent
  sequence
    decorator filter %this,state,dead
    macro setCharAni, dead
    getParent 


You may note that what was once this.path.size() is now %path_size. Unfortunately, I don't have any real way to allow calling a function of an object like that, so for situations like that you'll have to save info like that elsewhere, in this case a variable called path_size.

The next step is a Behavior Tree editor, so you won't have to mess with any of this!

[fowlplay4]

Like the format, but the getParent lines seem like it's redundant.

Alright, I'll probably never suggest XML again. Thanks for that little explanation.

[Fulg0reSama]

lol, Damn man. Just wanna say people this was fun to watch coreys work on. You wouldn't believe the RC spam it caused from the updates on it but it was very nice to see what came out of it. I think this could be a very nice advancement towards making gameplay better and efficient with the right people working with it. Definitely not me because I don't understand a lick of what this all does except for making baddies run more efficiently and probably allow more options to the creatures and such you create. Good job bro. +Rep

[DrakilorP2P]

Can you post a real example or two to prove that it works?

[coreys]

Originally Posted by DrakilorP2P

Can you post a real example or two to prove that it works?

It's in the works! I've also gotten a lot done on a graphical behavior editor for these.

[adam]

Your dedication is admirable!

[coreys]

I'm sorry for this huge delay in getting this out (just been so busy) but I finally have a graphical Behavior Editor! (As well as a new shiny update to the behavior trees) My next task is a fully working example AI.

Behavior Editor Version 1.0

This simple to use GUI will allow you to quickly and easily create and edit AI Behaviors on the fly. To fire up this GUI simple use the command "/behavioredit".

All behaviors are saved as behavior files in the "behaviors/" directory, so be sure to give your NPC-Server access to this directory.

As stated in the last update, you can load a behavior file as such:

PHP Code:

this.behavior = new TStaticVar();
this.behavior.join("ai-behaviortree");
this.behavior.loadFromFile("behavior_tree_name", this); 


Behavior Trees Version 1.2.1
Several updates here.

• All root nodes are selectors now, which is initialized with just "root".
• Because all roots are now selectors, the behavior file syntax no longer needs the root function (so no "rootSelector" or "rootSequence").
• Selectors now cache the last child node that succeeded (returned true) and tries that node first.
• The loop function will now loop until a node returns false if the loop number argument is -1.
• Added security to the loadFromFile function so that allow certain function names.

Download
The full set, along with it's dependencies, can be downloaded here.

[Fulg0reSama]

Looks like the interface is stupid easy to follow, Only issue is figuring how it all works. Great job man.

[napo_p2p]

When I was in school, I did a lot of research projects in robotics, but never had the chance to get into AI behavior trees too much. So, this was definitely interesting for me to look at. If I ever get back into the Graal coding trenches, this is one thing I'm sure to play around with. Great job!

The only suggestion I have is: attach your code! Heaven forbid, coreymedia goes down and poor little Billy can't tinker with your behavior editing goodness.

[coreys]

Haha, well I intend to have that site up for some time, so if it goes down I'll know to do that.