Class BehaviourTree
Representation of behaviour trees (or forests) with separated important and additional data.
The main advantage of this structure is that all properties of Nodes are stored directly, while additional data needed for other purposes, eg. editing in BtCreator, are stored in a separate table.
However, for a user, it is possible to store any properties on the nodes themselves and they get assigned to the appropriate table.
Functions
-
BehaviourTree.list (project)
-
Lists all available BehaviourTrees.
Parameters:
Returns:
{string}
Array of behaviour tree names
-
BehaviourTree.load (name)
-
Loads a previously saved tree.
Parameters:
- name
name under which to look for the tree
Returns:
BehaviourTree
loaded tree if found, nil otherwise
-
BehaviourTree.save (bt, name)
-
Saves the tree under the specified name.
Parameters:
- bt
the tree which to save
- name
name under which to save, must not contain path-illegal characters
Returns:
true if successful, nil otherwise
-
BehaviourTree:New ()
-
Creates a new instance of BehaviourTree
Returns:
BehaviourTree
Tables
-
BehaviourTree
-
Stored fields.
Fields:
- root
Node
main tree or
nil
- additionalNodes
{Node,...}
list of subtrees that are not connected to the root
- properties
{[string]=tab}
additional data of nodes, accessed through their Node
.id
Methods
-
BehaviourTree:Combine (other, f)
-
Add all nodes from the other tree to the current one.
Parameters:
- other
BehaviourTree
The other tree.
- f
func
Optional, function that is to be applied to each node of the other tree before it is combined, e.g. ID changes, return value is ignored.
Returns:
Node
The original root of the other tree.
-
BehaviourTree:NewNode (params)
-
Creates a new Node that belongs to the tree.
Remarks:
The children field of the params is a list of already created nodes (and not only their own params).
Parameters:
- params
parameters of the node, such as
id, nodeType, parameters and children
Returns:
Node
the created node
-
BehaviourTree:Save (name)
-
Alias to BehaviourTree.save
Parameters:
-
BehaviourTree:SetRoot (root)
-
Roots the behaviour tree on the specified, already created node.
Parameters:
- root
Node
Node that becomes the new root.
-
BehaviourTree:Visit (f[, after])
-
Invokes the given function on all nodes of the tree depth-first.
The traversing of the tree is terminated early if the function returns something.
Parameters:
- f
func
The function that is to be invoked for every node.
- after
func
Function that should be invoked when traversing out from the tree.
(optional)
Returns:
Whatever the function f returned along the way, or nil
Class Node
Represents a single node of
BehaviourTree
-
Node
-
Directly stored fields.
Whenever any other name is accessed (get or set), it is routed to the properties field of BehaviourTree under the id of the current node.
Fields:
- id
string
ID of the node
- nodeType
string
specifies the type of the Node.
- parameters
{Parameter,...}
list of parameters containing their
names and values.
- children
{Node,...}
list of current children of the node
-
Node:ChangeID (newId)
-
Changes the ID of the node.
This has to be used over simply changing the value of the
id slot in order to properly transfer the additional properties of the node.
Parameters:
-
Node:Connect (toNode)
-
Connect the node to another, making it its child
Parameters:
- toNode
node to which to connect
-
Node:Disconnect (fromNode)
-
Disconnects the node from its child.
Parameters:
- fromNode
the child node from which to disconnect
-
Node:Relocate (newTree)
-
Informs the node that it is relocated to a new tree.
It only affects the internal link to the tree and the
properties table, the additionalNodes and root are not affected and have to be handled by the caller.
Parameters:
- newTree
the new BehaviourTree the node now belongs to
-
Node:Remove ()
-
Removes the node from its tree.
Any nodes below this node get added to the
additionalNodes list.