StateTree Tools

Ready-made StateTree tools for Unreal Engine 5

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Primitive Event Forwarder

Plugin: StateTreeToolsCore Class: UPrimitiveEventForwarder Available since: StateTree Tools 2.0

Bridges the primitive component collision and interaction system with the StateTree event system. Add this component to any actor that has a UPrimitiveComponent (e.g. a sphere collider, static mesh, or skeletal mesh). At runtime it binds to that primitive’s delegates and fires StateTree events for overlaps, hits, physics state changes, cursor interaction, and touch input — so your StateTree can react to these without any custom C++.

Configuration

Primitive Component

The UPrimitiveComponent on the owner actor to watch. Select from the dropdown — only primitive components present on the actor are listed. This must be set; leaving it as None is a Blueprint compile error.

State Tree Component Name

The name of the UStateTreeComponent on the owner to send events to. Leave as None (default) to broadcast to every StateTree component on the actor. Set this if the actor has multiple StateTree components and you want to target only one.

Events Fired

All events are sent to the UStateTreeComponent(s) on the same actor (filtered by State Tree Component Name if set). Every payload includes a SourceComponent field pointing to the primitive that fired the event.

Overlap

`StateTreeTools.Events.Primitive.BeginOverlap`

Payload: FPrimitiveBeginOverlapPayload

Field	Type	Description
`SourceComponent`	`UPrimitiveComponent*`	The watched primitive
`OtherActor`	`AActor*`	The other actor involved in the overlap
`OtherComp`	`UPrimitiveComponent*`	The other component involved
`OtherBodyIndex`	`int32`	Body index on the other component
`bFromSweep`	`bool`	Whether the overlap was triggered by a sweep
`SweepResult`	`FHitResult`	Hit result if triggered by a sweep

`StateTreeTools.Events.Primitive.EndOverlap`

Payload: FPrimitiveEndOverlapPayload

Field	Type	Description
`SourceComponent`	`UPrimitiveComponent*`	The watched primitive
`OtherActor`	`AActor*`	The other actor
`OtherComp`	`UPrimitiveComponent*`	The other component
`OtherBodyIndex`	`int32`	Body index on the other component

Hit

`StateTreeTools.Events.Primitive.Hit`

Payload: FPrimitiveHitPayload

Field	Type	Description
`SourceComponent`	`UPrimitiveComponent*`	The watched primitive
`OtherActor`	`AActor*`	The actor that was hit
`OtherComp`	`UPrimitiveComponent*`	The component that was hit
`NormalImpulse`	`FVector`	The normal impulse applied at the hit
`Hit`	`FHitResult`	Full hit result

Physics

`StateTreeTools.Events.Primitive.Wake`

Payload: FPrimitiveWakePayload

Field	Type	Description
`SourceComponent`	`UPrimitiveComponent*`	The watched primitive
`BoneName`	`FName`	The bone that woke (skeletal meshes)

`StateTreeTools.Events.Primitive.Sleep`

Payload: FPrimitiveSleepPayload

Field	Type	Description
`SourceComponent`	`UPrimitiveComponent*`	The watched primitive
`BoneName`	`FName`	The bone that went to sleep (skeletal meshes)

`StateTreeTools.Events.Primitive.PhysicsStateChanged`

Payload: FPrimitivePhysicsStateChangedPayload

Field	Type	Description
`SourceComponent`	`UPrimitiveComponent*`	The watched primitive
`StateChange`	`EComponentPhysicsStateChange`	Whether physics was `Created` or `Destroyed`

Cursor

`StateTreeTools.Events.Primitive.BeginCursorOver`

Payload: FPrimitiveBeginCursorOverPayload

Field	Type	Description
`SourceComponent`	`UPrimitiveComponent*`	The watched primitive

`StateTreeTools.Events.Primitive.EndCursorOver`

Payload: FPrimitiveEndCursorOverPayload

Field	Type	Description
`SourceComponent`	`UPrimitiveComponent*`	The watched primitive

Click / Release

`StateTreeTools.Events.Primitive.Clicked`

Payload: FPrimitiveClickedPayload

Field	Type	Description
`SourceComponent`	`UPrimitiveComponent*`	The watched primitive
`ButtonPressed`	`FKey`	The mouse button that was pressed

`StateTreeTools.Events.Primitive.Released`

Payload: FPrimitiveReleasedPayload

Field	Type	Description
`SourceComponent`	`UPrimitiveComponent*`	The watched primitive
`ButtonReleased`	`FKey`	The mouse button that was released

Touch

`StateTreeTools.Events.Primitive.InputTouchBegin`

Payload: FPrimitiveInputTouchBeginPayload

Field	Type	Description
`SourceComponent`	`UPrimitiveComponent*`	The watched primitive
`FingerIndex`	`ETouchIndex::Type`	The touch finger index

`StateTreeTools.Events.Primitive.InputTouchEnd`

Payload: FPrimitiveInputTouchEndPayload

Field	Type	Description
`SourceComponent`	`UPrimitiveComponent*`	The watched primitive
`FingerIndex`	`ETouchIndex::Type`	The touch finger index

`StateTreeTools.Events.Primitive.InputTouchEnter`

Payload: FPrimitiveInputTouchEnterPayload

Field	Type	Description
`SourceComponent`	`UPrimitiveComponent*`	The watched primitive
`FingerIndex`	`ETouchIndex::Type`	The touch finger index

`StateTreeTools.Events.Primitive.InputTouchLeave`

Payload: FPrimitiveInputTouchLeavePayload

Field	Type	Description
`SourceComponent`	`UPrimitiveComponent*`	The watched primitive
`FingerIndex`	`ETouchIndex::Type`	The touch finger index

Setup

Add UPrimitiveEventForwarder to your actor.
In the Primitive Component dropdown, select the primitive to watch.
In your StateTree, add a transition with On Event set to the desired tag (e.g. StateTreeTools.Events.Primitive.BeginOverlap).
In the transition’s Payload Struct field, select the matching payload type (e.g. FPrimitiveBeginOverlapPayload). If the payload type is wrong or left unset, the event will not match and the transition will never fire.
Bind payload fields using the StateTree binding system.

The component logs a warning and becomes inactive at runtime if the named primitive is not found on the owner.

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