PossessInteraction

Concrete Interaction that triggers possession of the interactable's entity. When executed, the interactor's possessor takes control of the interactable's possessable, optionally releasing all current possessions first.

Definition

Namespace: Paragon.Townskeep.PossessionSystem Assembly: Townskeep.dll

public class PossessInteraction : Interaction

Inheritance: Action → Interaction → PossessInteraction

Remarks

PossessInteraction bridges the Interaction System with the Possession System. It is configured as an entry in an InteractionTable on possessable entities, allowing players or AI to trigger possession via the standard interaction pipeline.

The interaction resolves the possessor and possessable through component lookups:

1. Possessor — obtained from the interactor's Possessable component via GetPossessor(). This means the interactor must itself be possessed (the interacting body is possessed by something, and that something becomes the new possessor).

2. Possessable — obtained directly from the interactable's Possessable component.

This interaction completes synchronously (Task.CompletedTask). Possession is instant — any transition animations should be handled by PossessAction instances configured on the Possessor and Possessable components.

Quick Lookup

Goal	How
Enable possession via interaction	Add PossessInteraction to target's InteractionTable
Release previous possessions	Set releaseAllPossessions = true (default)
Keep existing possessions	Set releaseAllPossessions = false

Fields

releaseAllPossessions

Whether to release all current possessions before possessing the new target. Exposed as an Action Variable for external configuration.

[Variable]
private bool releaseAllPossessions = true

Default: true

Methods

OnExecute (override)

Resolves the possessor/possessable pair and executes possession.

protected override Task OnExecute()

Pipeline:

1. Get Possessor from Interactor.gameObject.GetComponent<Possessable>().GetPossessor()

2. Get Possessable from Interactable.GetComponent<Possessable>()

3. If releaseAllPossessions is true, call possessor.ReleaseAll()

4. Call possessor.Possess(possessable)

Returns: Task.CompletedTask (synchronous).

Common Pitfalls

Interactor must be a possessed entity The interaction resolves the possessor via Interactor.gameObject.GetComponent<Possessable>().GetPossessor(). If the interactor's GameObject does not have a Possessable component, or if that Possessable is not currently possessed, this will throw a NullReferenceException.

Interactable must have Possessable The target Interactable must have a Possessable component on the same GameObject. Without it, GetComponent<Possessable>() returns null.

ReleaseAll fires before Possess When releaseAllPossessions is true, all current possessions are released (triggering their release actions and events) before the new possession begins. Ordering matters if release actions affect state that the possess action depends on.

Examples

Configuring in InteractionTable

To make an NPC possessable via interaction:

1. Add an Interactable component to the NPC

2. Add a Possessable component to the NPC

3. In the InteractionTable, add an InteractionContext with:

   • Interaction: PossessInteraction

   • Trigger: appropriate trigger (e.g., ClickTrigger)

   • Conditions: as needed (e.g., proximity check)

Setting releaseAllPossessions via Variable

// Before executing, override the variable externally
interaction.SetVariable("releaseAllPossessions", false);

See Also

• Interaction — base class for interaction logic

• PossessAction — actions fired during possess/release transitions

• Possessor — component that takes control

• Possessable — component that can be controlled