Add custom blueprint to Carla blueprints library/actors registry Carla 0.9.15

[astralmaster]

I have a custom blueprint that I created in Carla's Unreal Editor 4 that is based on static mesh I imported to Carla using make import. This blueprint has some logic/code to it, I can drag and drop it to the map and it works fine, but I want to be able to spawn it in Carla using python API. What is the right way to make Carla 'see' my custom blueprint so that it is available for spawning in the blueprints library? Carla 0.9.15

The closest issue to this I could find was #3580 , however, my blueprint is not a Sensor, but rather a moving object (let's say its a rolling ball)

[Blyron]

That is not possible in 0.9.15

[astralmaster]

That is not possible in 0.9.15

Is it possible in another version?
Doesn't have to be specifically available in blueprints library, just has to be spawnable on demand. (even if it means modifying CarlaServer C++ code to add custom command, etc). Just looking for a direct/simple way.

[Blyron]

In ue4-dev branch exist a blueprintfactory. I think you can add your custom class there and spawn from python

[astralmaster]

In ue4-dev branch exist a blueprintfactory. I think you can add your custom class there and spawn from python

Are you referring to CarlaBlueprintRegistry? The AddToCarlaBlueprintRegistry method in there doesn't seem to support adding existing blueprints created in UE.
I couldn't find any references to blueprintfactory except this.

[Blyron]

My bad I thought it was implemented but it is not. For that purpouse you will need to create a new factory in Ue5 dev branch exists
Unreal/CarlaUnreal/Plugins/Carla/Source/Carla/Actor/Factory/BlueprintActorFactory.h
Unreal/CarlaUnreal/Plugins/Carla/Source/Carla/Actor/Factory/BlueprintActorFactory.cpp

[astralmaster]

That looks promising! Thank you, I will try porting this to UE4, if successful, I will do a pr, hopefully it will help others too.

[Blyron]

Okay thanks. Remember to add a doc if you want to have more exposition!

[uuauto2024]

Hi, I am facing the same issue, have you found any solution?

[astralmaster]

Hi, I am facing the same issue, have you found any solution?

Yes, I ported the code from ue5-dev branch that adds the ability to import blueprints to my custom ue4 branch as suggested by @Blyron . I also created a pr for ue4-dev branch.

[CorneliusHsiao]

Thanks @astralmaster for your implementations. I want to mention several more steps that are necessary to make blueprint import function work on my pull of ue4-dev:

1. In Unreal\CarlaUE4\Plugins\Carla\Source\Carla\Actor\ActorBlueprintFunctionLibrary.h, add #include "Carla/Actor/BlueprintParameters.h".
2. Copy BlueprintParameters.h from ue5-dev branch to Unreal\CarlaUE4\Plugins\Carla\Source\Carla\Actor\BlueprintParameters.h.
3. In Unreal\CarlaUE4\Plugins\Carla\Source\Carla\Game\CarlaGameModeBase.cpp, add the following in the implementation of ACarlaGameModeBase::ACarlaGameModeBase:

  ...
  TaggerDelegate = CreateDefaultSubobject<UTaggerDelegate>(TEXT("TaggerDelegate"));
  CarlaSettingsDelegate = CreateDefaultSubobject<UCarlaSettingsDelegate>(TEXT("CarlaSettingsDelegate"));

  # ===== NEW ===== #
  ActorFactories.Add(ABlueprintActorFactory::StaticClass());
  # ===== END OF NEW ===== #
}

const FString ACarlaGameModeBase::GetRelativeMapPath() const
{
  ...

4. In Unreal\CarlaUE4\Plugins\Carla\Source\Carla\Game\CarlaGameModeBase.h, add #include "Carla/Actor/Factory/BlueprintActorFactory.h".

Then, after a successful build of make PythonAPI and make launch, I am able to find the customized blueprints within world.get_blueprint_library().

Also to mention the static mesh embedded in the blueprints were not correctly linked somehow, so I have to re-import them in the UE4 later.

[gugomea]

Thanks for the patch CorneliusHsiao , it also works for me with the editor binary (make launch) , do you know how to make it work when packaging the binary (no editor) ? I don't see the BlueprintActorFactory in the files of the packaged version.

[astralmaster]

I’ll be making a pr that works with packaged version soon.