UGantryExperienceStage

#include "Experience/GantryExperienceStage.h"

One step of an experience activation, run in order and awaited.

You add stages to an experience's Stages list and configure each one there. Gantry runs them in order and waits for each to finish before starting the next, so a stage can take as long as it needs. When the experience ends, Gantry undoes them in reverse order.

In Blueprint

Create a Blueprint class of Gantry Experience Stage and implement the Begin Stage event. Call Finish Stage when the work is done: at once, or after a Delay, an async load, anything. A stage that does not implement Begin Stage finishes as soon as it starts. Implement End Stage to undo the work.

Variables marked Instance Editable appear in the experience's Stages list, so each experience configures its own copy. The stage has a world while it runs, so world nodes (Spawn Actor, Delay, Get Game State) work without a context pin.

In C++

Override BeginStage. Call StartStage first, then FinishStage when done, immediately or frames later. The default implementation runs the Blueprint event, or finishes at once without one. Override EndStage to undo the work, and call Super so a Blueprint subclass's End Stage still runs.

Stages run on the game thread. Each activation runs its own copy of the stage, never the object on the experience asset, so a stage may keep state in its variables.

Reports the stage's completion; the experience moves to the next stage, or fails and unwinds when it did not succeed.

Only the first call after the stage begins counts.

Name shown in progress reporting.

Override in Blueprint or C++ (GetStageDisplayName_Implementation).

Tag identifying the kind of work, e.g.

Gantry.Experience.Stage.LoadAssets. Override in Blueprint or C++ (GetStageTag_Implementation).

Whether the stage is running: between Begin Stage and Finish Stage.

The stage's work, in Blueprint.

Call Finish Stage when it is done, successful or not; until then the experience waits. Without an implementation the stage finishes at once.

Undo the stage's work, in Blueprint.

Runs on deactivation in reverse stage order, and also for a stage that failed or never finished, so it must tolerate both.

virtual UWorld * UGantryExperienceStage::GetWorld() const override

The world of the run this stage belongs to, so Blueprint world nodes work inside a stage.

Returns: The world while the stage is part of a run; null for the stage objects on an experience asset, which never run.

virtual void UGantryExperienceStage::BeginStage(const FGantryExperienceStageContext &Context, FOnStageFinished OnFinished)

Starts the stage.

Overrides call StartStage(OnFinished) first, then FinishStage when complete, which may be immediately. The default implementation runs the Begin Stage Blueprint event when a Blueprint implements it, and otherwise finishes successfully at once.

virtual void UGantryExperienceStage::EndStage(const FGantryExperienceStageContext &Context)

Undoes whatever BeginStage did.

Called in reverse order on deactivation, and may be called on a stage that never began or did not finish, so implementations must tolerate both. The default implementation runs the End Stage Blueprint event; overrides call Super.