Verse API reference page for the stackable_component class | Fortnite Documentation

A component that when attached to an entity allows for it to merge or 'stack' with other entities with compatible components.


Verse `using` statement	`using { /Verse.org/SceneGraph }`

Inheritance Hierarchy

This class is derived from component.

Name Description

Name	Description
`component`	Base class for authoring logic and data in the SceneGraph. Using components you can author re-usable building blocks of logic and data which can then be added to entities in the scene. Components are a very low level building block which can be used in many ways. For example: Exposing engine level concepts like mesh or sound Adding gameplay capabilities like damage or interaction Storing an inventory for a character in the game As components are generic there is no specific way that they must be used. It is up to the needs of your experience if you use one big game component or if you break up logic into many small components. Classes deriving from component must also specify `<final_super>` to be added to entities. This ensures the class will always derive directly from `component`. Further subclassing of the initial derived component is allowed and does not require specifying `<final_super>` on the derived classes. Only one instance of a component from each subclass group can be added to an entity at a time. For example, given this group of components, only one light_component can exist on a single entity. To create multiple lights you should use multiple entities. light_component := class(component){} capsule_light_component := class(light_component){} directional_light_component := class(light_component){} spot_light_component := class(light_component){} sphere_light_component := class(light_component){} rect_light_component := class(light_component){} ============================================================================== Component Lifetime Components move through a series of lifetime functions as they are added to entities, added to the scene, and begin running in the simulation. Components should override these methods to perform setup and run their simulation. As a component shuts down it will then move through shutdown version of these functions, giving users the opportunity to clean up any retained state on the component before it is disposed . Lifetime Methods: OnAddedToScene OnBeginSimulation -> OnSimulate OnEndSimulation OnRemovingFromScene ==============================================================================

component

Base class for authoring logic and data in the SceneGraph. Using components you can author re-usable building blocks of logic and data which can then be added to entities in the scene.

Components are a very low level building block which can be used in many ways. For example:

Exposing engine level concepts like mesh or sound
Adding gameplay capabilities like damage or interaction
Storing an inventory for a character in the game

As components are generic there is no specific way that they must be used. It is up to the needs of your experience if you use one big game component or if you break up logic into many small components.

Classes deriving from component must also specify <final_super> to be added to entities. This ensures the class will always derive directly from component. Further subclassing of the initial derived component is allowed and does not require specifying <final_super> on the derived classes.

Only one instance of a component from each subclass group can be added to an entity at a time. For example, given this group of components, only one light_component can exist on a single entity. To create multiple lights you should use multiple entities.

light_component := class(component){} capsule_light_component := class(light_component){} directional_light_component := class(light_component){} spot_light_component := class(light_component){} sphere_light_component := class(light_component){} rect_light_component := class(light_component){}

============================================================================== Component Lifetime

Components move through a series of lifetime functions as they are added to entities, added to the scene, and begin running in the simulation. Components should override these methods to perform setup and run their simulation.

As a component shuts down it will then move through shutdown version of these functions, giving users the opportunity to clean up any retained state on the component before it is disposed . Lifetime Methods: OnAddedToScene OnBeginSimulation -> OnSimulate OnEndSimulation OnRemovingFromScene ==============================================================================

Members

This class has both data members and functions.

Data

Data Member Name	Type	Description
`ChangeMaxStackSizeEvent`	`unknown`
`ChangeStackSizeEvent`	`unknown`
`Entity`	`entity`	The parent entity of this component. Components must have a parent entity pointer provided when being constructed. Components cannot be moved between parents.
`MaxStackSize`	`??int`	The maximum amount this component can hold. If unset, it holds an unlimited amount.
`StackSize`	`?int`	The current amount of this entity held in the stack.
`TickEvents`	`?tick_events`	Set callbacks to `TickEvents.PrePhysics` and `TickEvents.PostPhysics` to receive per-frame updates before and after physics is updated on your object.

Functions

Function Name	Description
`CanMergeInto`	Succeeds if this entity can be merged into the target entity. Merging an entity with itself will always fail. Note that merging should be checked in both directions!
`IsInScene`	Succeeds if the component is currently in the scene. After `OnAddedToScene` is called this call succeeds. After `OnRemovingFromScene` is called this call fails.
`IsSimulating`	Succeeds if the component is currently simulating. After `OnBeginSimulation` is called this call succeeds. After `OnEndSimulation` is called this call fails.
`MergeInto`	Attempts to merge this entity into the specified entity. Fails if entities cannot be merged. If TargetAmount is specified, only that amount will try to be merged into this entity. By default, the entire stack will try to merge. If the specified amount is invalid, the merge will fail.
`OnAddedToScene`	Called when the component is added to the scene by parenting it under the simulation entity or another entity already in the scene. Querying for components in the scene is valid after this phase completes.
`OnBeginSimulation`
`OnBeginSimulation`	Called when the component begins simulating within the scene. Use this to set up TickEvent callbacks or other setup that must be guaranteed to complete immediately. `OnAddedToScene` is guaranteed to run before `OnBeginSimulation`.
`OnEndSimulation`
`OnEndSimulation`	Called when the component ends simulation within the scene. Simulation ends on a component when the experience resets, the parent entity is removed from the scene. Cached TickEvents cancelables should be canceled in `OnEndSimulation`. `OnSimulate` task will be canceled before `OnEndSimulation` is called. `OnEndSimulation` is only called on components that have already had `OnBeginSimulation` called.
`OnReceive`	Respond to a scene event. Return true to consume the event and halt propagation to the next entity.
`OnRemovingFromScene`	Called when the component is about to be removed from the scene. Components are removed from a scene when the parent entity is removed from the scene. `OnRemovingFromScene` is only called on components that have already had `OnAddedToScene` called.
`OnSimulate`	Called when the component begins simulating within the scene. Use this to add asynchronous/suspends update logic for a component. `OnBeginSimulation` is guaranteed to run before `OnSimulate`. `OnSimulate` will be cancelled before `OnEndSimulation`
`RemoveFromEntity`	Removes the component from the entity. Removed components are removed from the scene and can only be added back to the same entity. Flows through `OnEndSimulation`-> `OnRemovingFromScene`.
`SendDown`	Send a scene event to this component, invoking OnReceive. Returns true if any participant consumed the event.
`SetMaxStackSize`	Sets the maximum stack size for this component. If NewMaxStackSize is false, stack size is unlimited. If ClampStackSize is true, StackSize will be clamped to NewMaxStackSize.
`SetStackSize`	Sets the stack size of this component. If the provided stack size is invalid, e.g. negative or exceeding MaxStackSize, stack size will not change.
`Split`