Behavior Tree Node Reference: Services

Reference for the Behavior Tree Service nodes.

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Services attach to Composite or Task nodes and will execute at their defined frequency as long as their branch is being executed. These are often used to make checks and to update the Blackboard. These take the place of traditional Parallel nodes in other Behavior Tree systems.

Default Focus

Default_Focus.png

The Default Focus creates a shortcut to accessing an Actor in your Blueprints and Code by setting the focus of the AI Controller. By setting the focus of the AI Controller to an Actor, you can directly access it from the AI Controller instead of accessing a Blackboard key.

Property

Description

Blackboard Key

This takes in an Actor Key (an Object Key with its base class set to Actor) to be quickly referenced by the AI Controller using GetFocusActor.

Node Name

The name the node should display in the Behavior Tree graph.

Run EQS

RunEQS_Image.png

The Run EQS Service node can be used to regularly execute an Environmental Query System (EQS) template at assigned intervals and can update a specified Blackboard Key.

Property

Description

Query Template

The EQS asset to run.

Query Config

Optional array of additional parameters to include in the query.

EQSQuery Blackboard Key

Option to use a Blackboard Key that stores an EQS Query Template instead of a specified EQS Query Template.

Run Mode

Single Best Item

Pick the first item with the best score.

Single Random Item from Best 5%

Pick a random item with score 95% to 100% of max.

Single Random Item from Best 25%

Pick a random item with score 75% to 100% of max.

All Matching

Get all items that match conditions.

Blackboard Key

The Blackboard Key the Service will write results into - either an FVector or an Actor.

Interval

Defines the time span between subsequent ticks of the Service.

Random Deviation

Adds a random range value to the Service's Interval value.

Call Tick on Search Start

Call Tick Event when Task search enters this node (Search Start will be called as well).

Restart Timer on Each Activation

If set, the next Tick time will be always reset to Service's Interval value when the node is activated.

Node Name

The name the node should display in the Behavior Tree graph.

Custom Services

NewCustomService_01.png

You can create Services by clicking the New Service button from the toolbar that contains Blueprint logic and (or) parameters.

NewCustomService.png

Blueprint Services are less performant than C++ Services. If optimization is a concern, you may want to use native Services.

The following properties are also available when creating a Service.

Property

Description

Show Property Details

Shows detailed information about properties when enabled.

Show Event Details

Shows detailed information about implemented Events when enabled.

Node Name

The name the node should display in the Behavior Tree graph.

Interval

Defines the time span between subsequent ticks of the Service.

Random Deviation

Adds a random range value to the Service's Interval value.

Call Tick on Search Start

Call Tick Event when Task search enters this node (Search Start will be called as well).

Restart Timer on Each Activation

If set, the next Tick time will be always reset to Service's Interval value when the node is activated.

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