synopia / jbt

java behavior trees

Java Behavior Trees Framework

Small behavior tree framework. Trees can be built using groovy code:

 builder.tree {
     sequence() {
         sequence() {
             delay()
             act_print(arg: 'One')
             act_count_down(locals: ["count_down": 5])
             act_print(arg: 'Two')
             act_count_down(locals: ["count_down": 4])
             act_print(arg: 'Three')
         }
         sequence(debug: [execute: true]) {
             delay()
             act_print(arg: 'Start')
             act_count_down(locals: ["count_down": 2])
             succeed(id: 3,)
             succeed(id: 4)
             running(id: 5)
             fail(id: 6)
         }
     }
 }

Once you have a tree constructed (using builder or by directly wiring up the nodes), the tree is compiled into java bytecode. This bytecode may be used independently of the jbt:asm project (with all that fancy groovy stuff).

The compiled class has one method run() that runs the tree one full step and returns the new behavior state of the tree.

Behavior Nodes

• Succeed Always returns with success
• Fail Always returns with failure
• Run Always return with running
• Sequence Runs every child in a sequence. Return with failure, once a child fails
• Selector Runs every child until it returns success
• Parallel Runs every child parallel. Stops when one children fails or all are succeeded
• Dynamic Selector Works like a selector, but rechecks all failed children each tick
• Action Uses a callback to start any action
• Decorator Uses a callback to control the result of the decorated node

jbt's Issues

Finish, claim bounty :-)

Heya @synopia - been trying to get a hold of you, here's me trying a new way! :D

We're going to declare the Terasology engine v1.0.0 here after the holidays. While the existing behavior trees in the engine work, I know you've put a lot of effort into this second pass.

Do you have any time to get this back up to speed with the latest engine and (I think?) get it working as a module? We've been slowly building up some funds for code bounties and I'd be happy to drop a sizable one on this issue to get it finished, if that helps any :-)

Let me know! I hope all is well.