Added actor offset for carsim simulation.

Unreal/CarlaUE4/Plugins/Carla/Source/Carla/Util/EmptyActor.cpp

@@ -0,0 +1,16 @@
+// Copyright (c) 2020 Computer Vision Center (CVC) at the Universitat Autonoma
+// de Barcelona (UAB).
+//
+// This work is licensed under the terms of the MIT license.
+// For a copy, see <https://opensource.org/licenses/MIT>.
+
+#include "EmptyActor.h"
+
+AEmptyActor::AEmptyActor(const FObjectInitializer &ObjectInitializer)
+  : Super(ObjectInitializer)
+{
+  PrimaryActorTick.bCanEverTick = false;
+  RootSceneComponent = CreateDefaultSubobject<USceneComponent>(TEXT("SceneRootComponent"));
+  RootComponent = RootSceneComponent;
+  RootComponent->SetMobility(EComponentMobility::Movable);
+}

Unreal/CarlaUE4/Plugins/Carla/Source/Carla/Util/EmptyActor.h

@@ -0,0 +1,23 @@
+// Copyright (c) 2020 Computer Vision Center (CVC) at the Universitat Autonoma
+// de Barcelona (UAB).
+//
+// This work is licensed under the terms of the MIT license.
+// For a copy, see <https://opensource.org/licenses/MIT>.
+
+#pragma once
+
+#include "GameFramework/Pawn.h"
+#include "EmptyActor.generated.h"
+
+UCLASS()
+class CARLA_API AEmptyActor : public APawn
+{
+  GENERATED_BODY()
+
+public:
+  AEmptyActor(const FObjectInitializer &ObjectInitializer);
+
+private:
+  UPROPERTY(Category="Empty Actor", VisibleAnywhere, BlueprintReadOnly, meta = (AllowPrivateAccess = "true"))
+  USceneComponent* RootSceneComponent;
+};

Unreal/CarlaUE4/Plugins/Carla/Source/Carla/Vehicle/CarlaWheeledVehicle.cpp

@@ -15,6 +15,8 @@
 #include "PhysXVehicleManager.h"
 #include "TireConfig.h"
 #include "VehicleWheel.h"
+#include "Carla/Util/ActorAttacher.h"
+#include "Carla/Util/EmptyActor.h"
 
 #include "Rendering/SkeletalMeshRenderData.h"
 
@@ -587,8 +589,18 @@ void ACarlaWheeledVehicle::RevertToCarSimPhysics()
 void ACarlaWheeledVehicle::EnableCarSim(FString SimfilePath)
 {
   #ifdef WITH_CARSIM
-  CarSimMovementComponent = NewObject<UCarSimMovementComponent>(this);
-  ExternalMovementComponent = CarSimMovementComponent;
+  // workarround to compensate carsim coordinate origin offset
+  FActorSpawnParameters SpawnParams;
+  SpawnParams.SpawnCollisionHandlingOverride =
+      ESpawnActorCollisionHandlingMethod::AlwaysSpawn;
+  OffsetActor = GetWorld()->SpawnActor<AEmptyActor>(
+      GetActorLocation() + GetActorForwardVector() * CarSimOriginOffset,
+      GetActorRotation(),
+      SpawnParams);
+  CarSimMovementComponent = NewObject<UCarSimMovementComponent>(OffsetActor);
+
+  // CarSimMovementComponent = NewObject<UCarSimMovementComponent>(this);
+  // ExternalMovementComponent = CarSimMovementComponent;
   carla::log_warning("Loading simfile:", carla::rpc::FromFString(SimfilePath));
   GetVehicleMovementComponent()->SetComponentTickEnabled(false);
   GetVehicleMovementComponent()->Deactivate();
@@ -612,6 +624,13 @@ void ACarlaWheeledVehicle::EnableCarSim(FString SimfilePath)
   OnActorHit.AddDynamic(this, &ACarlaWheeledVehicle::OnCarSimHit);
   GetMesh()->OnComponentBeginOverlap.AddDynamic(this, &ACarlaWheeledVehicle::OnCarSimOverlap);
   GetMesh()->SetCollisionResponseToChannel(ECollisionChannel::ECC_WorldStatic, ECollisionResponse::ECR_Overlap);
+
+  // workaround to prevent carsim from interacting with its own car
+  GetMesh()->SetCollisionResponseToChannel(ECollisionChannel::ECC_Visibility, ECollisionResponse::ECR_Overlap);
+
+  // attach to actor with an offset
+  AttachToActor(OffsetActor, FAttachmentTransformRules::KeepWorldTransform);
+
   bCarSimEnabled = true;
   #endif
 }
@@ -644,4 +663,12 @@ bool ACarlaWheeledVehicle::IsCarSimEnabled() const
 {
   return bCarSimEnabled;
 }
+
+void ACarlaWheeledVehicle::EndPlay(const EEndPlayReason::Type EndPlayReason)
+{
+  if (OffsetActor)
+  {
+    OffsetActor->Destroy();
+  }
+}
 //-------------------------------------------

Unreal/CarlaUE4/Plugins/Carla/Source/Carla/Vehicle/CarlaWheeledVehicle.h

@@ -262,6 +262,8 @@ public:
   UFUNCTION(Category="CARLA Wheeled Vehicle", BlueprintPure)
   bool IsCarSimEnabled() const;
 
+  virtual void EndPlay(const EEndPlayReason::Type EndPlayReason);
+
 private:
 
   // On car mesh hit, only works when carsim is enabled
@@ -290,11 +292,15 @@ private:
   UPROPERTY(Category="CARLA Wheeled Vehicle", VisibleAnywhere)
   bool bCarSimEnabled = false;
 
+  UPROPERTY(Category="CARLA Wheeled Vehicle", EditAnywhere)
+  float CarSimOriginOffset = 150.f;
+
   // Small workarround to allow optional CarSim plugin usage
   UPROPERTY(Category="CARLA Wheeled Vehicle", VisibleAnywhere, BlueprintReadOnly, meta = (AllowPrivateAccess = "true"))
   UMovementComponent * ExternalMovementComponent;
 
   #ifdef WITH_CARSIM
+  AActor* OffsetActor;
   // Casted version of ExternalMovementComponent
   UCarSimMovementComponent * CarSimMovementComponent;
   #endif