Fixed server-client sincronization for map change.

LibCarla/source/carla/client/detail/Client.cpp

@@ -145,6 +145,10 @@ namespace detail {
     _pimpl->CallAndWait<void>("load_new_episode", std::move(map_name));
   }
 
+  bool Client::CheckIntermediateEpisode() {
+    return _pimpl->CallAndWait<bool>("check_intermediate_episode");
+  }
+
   void Client::CopyOpenDriveToServer(std::string opendrive, const rpc::OpendriveGenerationParameters & params) {
     // Await response, we need to be sure in this one.
     _pimpl->CallAndWait<void>("copy_opendrive_to_file", std::move(opendrive), params);

LibCarla/source/carla/client/detail/Client.h

@@ -88,6 +88,8 @@ namespace detail {
 
     void LoadEpisode(std::string map_name);
 
+    bool CheckIntermediateEpisode();
+
     void CopyOpenDriveToServer(
         std::string opendrive, const rpc::OpendriveGenerationParameters & params);
 

LibCarla/source/carla/client/detail/Simulator.cpp

@@ -90,7 +90,7 @@ namespace detail {
       using namespace std::literals::chrono_literals;
       _episode->WaitForState(10ms);
       auto episode = GetCurrentEpisode();
-      if (episode.GetId() != id) {
+      if (episode.GetId() != id && !_client.CheckIntermediateEpisode()) {
         return episode;
       }
     }

Unreal/CarlaUE4/Plugins/Carla/Source/Carla/Game/CarlaGameInstance.h

@@ -87,6 +87,10 @@ public:
 
   void CheckAndLoadMap(UWorld *world, UCarlaEpisode &Episode);
 
+  bool IsLevelPendingLoad() const {
+    return bShouldLoadLevel;
+  }
+
 private:
 
   UPROPERTY(Category = "CARLA Settings", EditAnywhere)

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

@@ -228,14 +228,32 @@ void FCarlaServer::FPimpl::BindActions()
   BIND_SYNC(load_new_episode) << [this](const std::string &map_name) -> R<void>
   {
     REQUIRE_CARLA_EPISODE();
-    UCarlaStatics::GetGameInstance(Episode->GetWorld())->SetMapToLoad(cr::ToFString(map_name));
-    if (!Episode->LoadNewEpisode(cr::ToFString("OpendriveMap")))
+    FString MapName = cr::ToFString(map_name);
+    auto Maps = UCarlaStatics::GetAllMapNames();
+    bool bMissingMap = true;
+    for (auto & Map : Maps)
+    {
+      if(Map.Contains(MapName))
+      {
+        bMissingMap = false;
+        break;
+      }
+    }
+    if(bMissingMap)
     {
       RESPOND_ERROR("map not found");
     }
+    UCarlaStatics::GetGameInstance(Episode->GetWorld())->SetMapToLoad(MapName);
+    Episode->LoadNewEpisode(cr::ToFString("EmptyMap"));
     return R<void>::Success();
   };
 
+  BIND_SYNC(check_intermediate_episode) << [this]() -> R<bool>
+  {
+    REQUIRE_CARLA_EPISODE();
+    return UCarlaStatics::GetGameInstance(Episode->GetWorld())->IsLevelPendingLoad();
+  };
+
   BIND_SYNC(copy_opendrive_to_file) << [this](const std::string &opendrive, carla::rpc::OpendriveGenerationParameters Params) -> R<void>
   {
     REQUIRE_CARLA_EPISODE();