Disable PhysXVehicleManager when physics are off

Unreal/CarlaUE4/Plugins/Carla/Source/Carla/Server/CarlaServer.cpp

@@ -915,10 +915,15 @@ void FCarlaServer::FPimpl::BindActions()
       RESPOND_ERROR("unable to set actor simulate physics: actor not found");
     }
 
-    auto Character = Cast<ACharacter>(ActorView.GetActor());
-    // The physics in the walkers works in a different way so to disable them,
+    auto* Character = Cast<ACharacter>(ActorView.GetActor());
+    auto* CarlaVehicle = Cast<ACarlaWheeledVehicle>(ActorView.GetActor());
+    // The physics in the vehicles works in a different way so to disable them.
+    if (CarlaVehicle != nullptr){
+      CarlaVehicle->SetSimulatePhysics(bEnabled);
+    }
+    // The physics in the walkers also works in a different way so to disable them,
     // we need to do it in the UCharacterMovementComponent.
-    if (Character != nullptr)
+    else if (Character != nullptr)
     {
       auto CharacterMovement = Cast<UCharacterMovementComponent>(Character->GetCharacterMovement());
 
@@ -938,24 +943,10 @@ void FCarlaServer::FPimpl::BindActions()
       {
         RESPOND_ERROR("unable to set actor simulate physics: not supported by actor");
       }
-      auto Vehicle = Cast<ACarlaWheeledVehicle>(ActorView.GetActor());
-      if(Vehicle)
-      {
-        Vehicle->SetActorEnableCollision(true);
-        #ifdef WITH_CARSIM
-        if(!Vehicle->IsCarSimEnabled())
-        #endif
-        {
+
       RootComponent->SetSimulatePhysics(bEnabled);
       RootComponent->SetCollisionEnabled(ECollisionEnabled::QueryAndPhysics);
     }
-      }
-      else
-      {
-        RootComponent->SetSimulatePhysics(bEnabled);
-        RootComponent->SetCollisionEnabled(ECollisionEnabled::QueryAndPhysics);
-      }
-    }
 
     return R<void>::Success();
   };

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

@@ -635,6 +635,34 @@ void ACarlaWheeledVehicle::EnableCarSim(FString SimfilePath)
   #endif
 }
 
+void ACarlaWheeledVehicle::SetSimulatePhysics(bool enabled) {
+  UWheeledVehicleMovementComponent4W *Vehicle4W = Cast<UWheeledVehicleMovementComponent4W>(
+      GetVehicleMovement());
+  check(Vehicle4W != nullptr);
+
+  if(bPhysicsEnabled == enabled)
+    return;
+
+  SetActorEnableCollision(true);
+  #ifdef WITH_CARSIM
+  if(!IsCarSimEnabled())
+  #endif
+  {
+    auto RootComponent = Cast<UPrimitiveComponent>(GetRootComponent());
+    RootComponent->SetSimulatePhysics(enabled);
+    RootComponent->SetCollisionEnabled(ECollisionEnabled::QueryAndPhysics);
+
+    GetWorld()->GetPhysicsScene()->GetPxScene()->lockWrite();
+    if(enabled)
+      Vehicle4W->RecreatePhysicsState();
+    else
+      Vehicle4W->DestroyPhysicsState();
+    GetWorld()->GetPhysicsScene()->GetPxScene()->unlockWrite();
+  }
+
+  bPhysicsEnabled = enabled;
+}
+
 void ACarlaWheeledVehicle::UseCarSimRoad(bool bEnabled)
 {
   #ifdef WITH_CARSIM

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

@@ -124,6 +124,8 @@ public:
 
   void ApplyVehiclePhysicsControl(const FVehiclePhysicsControl &PhysicsControl);
 
+  void SetSimulatePhysics(bool enabled);
+
   void SetWheelCollision(UWheeledVehicleMovementComponent4W *Vehicle4W, const FVehiclePhysicsControl &PhysicsControl);
 
   void SetVehicleLightState(const FVehicleLightState &LightState);
@@ -295,6 +297,9 @@ private:
   UPROPERTY(Category="CARLA Wheeled Vehicle", EditAnywhere)
   float CarSimOriginOffset = 150.f;
 
+  UPROPERTY(Category="CARLA Wheeled Vehicle", VisibleAnywhere)
+  bool bPhysicsEnabled = true;
+
   // Small workarround to allow optional CarSim plugin usage
   UPROPERTY(Category="CARLA Wheeled Vehicle", VisibleAnywhere, BlueprintReadOnly, meta = (AllowPrivateAccess = "true"))
   UMovementComponent * ExternalMovementComponent;