Italink Unreal PIE Control
Control Play In Editor (PIE) and Simulate In Editor (SIE) sessions through UCP's call command.
Prerequisite: The unreal-client-protocol skill must be available and the UE editor must be running with the UCP plugin enabled.
Custom Function Library
UPIEOperationLibrary
CDO Path: /Script/UnrealClientProtocolEditor.Default__PIEOperationLibrary
| Function | Params | Returns | Description |
|---|---|---|---|
StartPIE |
(none) | bool |
Start a Play In Editor session |
StartSimulate |
(none) | bool |
Start a Simulate In Editor session |
StopPIE |
(none) | (void) | Stop the current PIE/SIE session |
IsInPIE |
(none) | bool |
Whether a play session is in progress |
IsSimulating |
(none) | bool |
Whether a simulate session is in progress |
PausePIE |
(none) | bool |
Pause all PIE worlds |
ResumePIE |
(none) | bool |
Resume all PIE worlds |
GetPIEWorlds |
(none) | TArray<UWorld*> |
Get all PIE world instances |
Examples
Start PIE:
{"object":"/Script/UnrealClientProtocolEditor.Default__PIEOperationLibrary","function":"StartPIE"}
Stop PIE:
{"object":"/Script/UnrealClientProtocolEditor.Default__PIEOperationLibrary","function":"StopPIE"}
Start Simulate:
{"object":"/Script/UnrealClientProtocolEditor.Default__PIEOperationLibrary","function":"StartSimulate"}
Check if PIE is running:
{"object":"/Script/UnrealClientProtocolEditor.Default__PIEOperationLibrary","function":"IsInPIE"}
Pause PIE:
{"object":"/Script/UnrealClientProtocolEditor.Default__PIEOperationLibrary","function":"PausePIE"}
Get PIE worlds:
{"object":"/Script/UnrealClientProtocolEditor.Default__PIEOperationLibrary","function":"GetPIEWorlds"}
Engine Built-in APIs
UEditorLevelLibrary
CDO Path: /Script/EditorScriptingUtilities.Default__EditorLevelLibrary
| Function | Description |
|---|---|
GetPIEWorlds() |
Get worlds from Play-In-Editor sessions (alternative to custom library) |
UGameplayStatics (on PIE worlds)
CDO Path: /Script/Engine.Default__GameplayStatics
Once PIE is running, UGameplayStatics functions automatically resolve to the PIE world (UCP's WorldContext auto-injection prefers PIE worlds):
| Function | Description |
|---|---|
GetPlayerPawn(WorldContextObject, PlayerIndex) |
Get the player pawn in PIE |
GetPlayerController(WorldContextObject, PlayerIndex) |
Get the player controller in PIE |
GetAllActorsOfClass(WorldContextObject, ActorClass) |
Find actors in the PIE world |
Common Patterns
Start PIE, then interact with PIE world
Start a play session, then query actors in the running game (run as separate calls):
{"object":"/Script/UnrealClientProtocolEditor.Default__PIEOperationLibrary","function":"StartPIE"}
After PIE starts, UCP auto-resolves WorldContext to the PIE world:
{"object":"/Script/Engine.Default__GameplayStatics","function":"GetPlayerPawn","params":{"PlayerIndex":0}}
Pause, inspect, resume
{"object":"/Script/UnrealClientProtocolEditor.Default__PIEOperationLibrary","function":"PausePIE"}
Inspect game state while paused, then resume:
{"object":"/Script/UnrealClientProtocolEditor.Default__PIEOperationLibrary","function":"ResumePIE"}
Check state before starting
{"object":"/Script/UnrealClientProtocolEditor.Default__PIEOperationLibrary","function":"IsInPIE"}
If false, start PIE. If true, stop first then restart if needed.
Key Rules
- Only one PIE/SIE session can be active at a time. Check
IsInPIEbefore starting. - StartPIE/StartSimulate are asynchronous — they queue the request, the session starts on the next editor tick. Subsequent calls to functions that depend on PIE being active should be sent as separate requests.
- StopPIE is also asynchronous — it queues the end request.
- WorldContext auto-resolution — when PIE is active, UCP automatically uses the PIE world for functions requiring
WorldContextObject.