Automatically tag objects on spawn

Source/Carla/Game/CarlaGameMode.cpp

@@ -14,9 +14,10 @@
 #include "CarlaSettings.h"
 #include "CarlaVehicleController.h"
 #include "Tagger.h"
+#include "TaggerDelegate.h"
 
-ACarlaGameMode::ACarlaGameMode() :
-  Super(),
+ACarlaGameMode::ACarlaGameMode(const FObjectInitializer& ObjectInitializer) :
+  Super(ObjectInitializer),
   GameController(nullptr),
   PlayerController(nullptr)
 {
@@ -27,6 +28,8 @@ ACarlaGameMode::ACarlaGameMode() :
   GameStateClass = ACarlaGameState::StaticClass();
   PlayerStateClass = ACarlaPlayerState::StaticClass();
   HUDClass = ACarlaHUD::StaticClass();
+
+  TaggerDelegate = CreateDefaultSubobject<UTaggerDelegate>(TEXT("TaggerDelegate"));
 }
 
 void ACarlaGameMode::InitGame(
@@ -44,6 +47,12 @@ void ACarlaGameMode::InitGame(
   GameController = &GameInstance->GetGameController();
   GameController->Initialize(GameInstance->GetCarlaSettings());
   GameInstance->GetCarlaSettings().LogSettings();
+
+  if (TaggerDelegate != nullptr) {
+    TaggerDelegate->RegisterSpawnHandler(GetWorld());
+  } else {
+    UE_LOG(LogCarla, Error, TEXT("Missing TaggerDelegate!"));
+  }
 }
 
 void ACarlaGameMode::RestartPlayer(AController* NewPlayer)
@@ -72,6 +81,7 @@ void ACarlaGameMode::BeginPlay()
   Super::BeginPlay();
   if (GameInstance->GetCarlaSettings().bSemanticSegmentationEnabled) {
     TagActorsForSemanticSegmentation();
+    TaggerDelegate->SetSemanticSegmentationEnabled();
   }
   GameController->BeginPlay();
 }

Source/Carla/Game/TaggerDelegate.cpp

@@ -0,0 +1,29 @@
+// CARLA, Copyright (C) 2017 Computer Vision Center (CVC)
+
+#include "Carla.h"
+#include "TaggerDelegate.h"
+
+#include "Engine/World.h"
+#include "Tagger.h"
+
+UTaggerDelegate::UTaggerDelegate() :
+  ActorSpawnedDelegate(FOnActorSpawned::FDelegate::CreateUObject(this, &UTaggerDelegate::OnActorSpawned)) {}
+
+void UTaggerDelegate::RegisterSpawnHandler(UWorld *InWorld)
+{
+  InWorld->AddOnActorSpawnedHandler(ActorSpawnedDelegate);
+}
+
+void UTaggerDelegate::OnActorSpawned(AActor* InActor)
+{
+  if (InActor != nullptr) {
+    ATagger::TagActor(*InActor, bSemanticSegmentationEnabled);
+
+    TArray<ECityObjectLabel> Tags;
+    ATagger::GetTagsOfTaggedActor(*InActor, Tags);
+    UE_LOG(LogCarla, Warning, TEXT("Tagged recently spawned actor \"%s\""), *InActor->GetName());
+    for (auto Tag : Tags) {
+      UE_LOG(LogCarla, Warning, TEXT("  - %d"), (uint8)Tag);
+    }
+  }
+}

Source/Carla/Game/TaggerDelegate.h

@@ -0,0 +1,31 @@
+// CARLA, Copyright (C) 2017 Computer Vision Center (CVC)
+
+#pragma once
+
+#include "TaggerDelegate.generated.h"
+
+/// Used to tag every actor that is spawned into the world.
+UCLASS()
+class CARLA_API UTaggerDelegate : public UObject
+{
+  GENERATED_BODY()
+
+public:
+
+  UTaggerDelegate();
+
+  void RegisterSpawnHandler(UWorld *World);
+
+  void SetSemanticSegmentationEnabled(bool Enable = true)
+  {
+    bSemanticSegmentationEnabled = Enable;
+  }
+
+  void OnActorSpawned(AActor *Actor);
+
+private:
+
+  FOnActorSpawned::FDelegate ActorSpawnedDelegate;
+
+  bool bSemanticSegmentationEnabled = false;
+};

Source/Carla/Tagger.cpp

@@ -68,10 +68,10 @@ static void SetStencilValue(
     UPrimitiveComponent &Component,
     const ECityObjectLabel &Label,
     const bool bSetRenderCustomDepth) {
+  Component.SetCustomDepthStencilValue(CastEnum(Label));
   Component.SetRenderCustomDepth(
       bSetRenderCustomDepth &&
-      !ATagger::MatchComponent(Component, ECityObjectLabel::None));
-  Component.SetCustomDepthStencilValue(CastEnum(Label));
+      (Label != ECityObjectLabel::None));
 }
 
 // =============================================================================