Use Chooser Plugin in C++

[InvQuasar]

Hi!
Has anyone tried using the Chooser plugin in code?
I want to rewrite a BP Evaluate Chooser node (screen 1) to C++ code, but I don’t understand how to do it correctly.

.h file

UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = "Player|Anim", meta = (AllowPrivateAccess = "true"))
TObjectPtr<class UChooserTable> AnimChooserTable = nullptr;

.cpp file

FTraversalChooserInputs* chooserInputs = new FTraversalChooserInputs(
  TraversalResult->ActionType,
  TraversalResult->HasFrontLedge,
  TraversalResult->HasBackLedge,
  TraversalResult->HasBackFloor,
  TraversalResult->ObstacleHeight,
  TraversalResult->ObstacleDepth,
  TraversalResult->BackLedgeHeight,
  GetCharacterMovement()->MovementMode,
  Gait,
  UKismetMathLibrary::VSizeXY(GetCharacterMovement()->Velocity)
);
FTraversalChooserOutputs* chooserOutputs;
TArray<UAnimMontage*> validMontages = UChooserFunctionLibrary::EvaluateChooserMulti(chooserInputs, AnimChooserTable, UAnimMontage::StaticClass());
// OR
TArray<UAnimMontage*> validMontages = UChooserFunctionLibrary::EvaluateObjectChooserBaseMulti(AnimChooserTable, chooserInputs, UAnimMontage::StaticClass());

I have 3 problems (questions):

1. Which fun is appropriate (or neither)? (screen 2 and screen 3)
   

   
   
   
   

2. How to correctly pass a struct rather than a class?

3. In addition to the result (TArray<UAnimMontage*>), how can I fill out the struct FTraversalChooserOutputs?

I will be glad for any help

[SpecZynk]

Hi,

I don’t know what is the behavior you are looking for, so from what I’ve understood from your code I can say you have done most of the work, so:

1. To create your FInstancedStruct use UChooserFunctionLibrary:

FInstancedStruct InstancedStruct = UChooserFunctionLibrary::MakeEvaluateChooser(ChooserTable);

2. To add input (entry) to your FChooserEvaluationContext use UChooserFunctionLibrary or its functions:

FChooserEvaluationContext EvaluationContext;

// Object
UChooserFunctionLibrary::AddChooserObjectInput(EvaluationContext, Object);
EvaluationContext.AddObjectParam(Object);
// Struct
UChooserFunctionLibrary::AddChooserStructInput(EvaluationContext, Struct);
EvaluationContext.AddStructParam(Struct)	

3. To get your out struct you can use the function below, since its params are references:

UChooserFunctionLibrary::GetChooserStructOutput(params)

4. After that you can proceed with UChooserFunctionLibrary::EvaluateChooserMult(params);

If I can give you a suggest, simple create a function that do all the work, and also return what you expect.

May that help you.

Bye

[InvQuasar]

Do I understand correctly that point 2 is needed not to add a new row to the table, but specifically to prepare input data for searching?
Because the table is already filled in. I just need to search in it.

[InvQuasar]

I tried to do it as I understood. But it turned out badly).

[InvQuasar]

The AddChooserStructInput() is not expecting a structure to input, but int32…

[InvQuasar]

The GetChooserStructOutput() expects 2 more additional parameters to input, one of which is also int32.

[InvQuasar]

And EvaluateChooserMulti() doesn’t want to accept my context because it expects a class, not a struct.

Sorry for writing this is separate messages. I can only attach one screenshot in one message.

[InvQuasar]

I apologize for asking strange questions. I don’t have much experience with the UE. And I’m trying to improve it.

P.S. For additional info. I’m using UE 5.5.3 version.

[SpecZynk]

Hey,

@InvQuasar

Sorry for writing this is separate messages. I can only attach one screenshot in one message.

No problem, that’s ok.

@InvQuasar

The AddChooserStructInput() is not expecting a structure to input, but int32…

That’s correct and make sense, if you take a look in your print, your ChooserTable set a enum that is inside your struct.

@InvQuasar

Your Enum ActionType comes from your struct FTraversalChooserOutputs, to better ilustrate, look this example:

.h file

UENUM(BlueprintType)
enum class ESVMovementState : uint8
{
	Idle,
	Walk,
	Run,
	Sprint
};

USTRUCT(BlueprintType)
struct FTraversalChooser
{
	GENERATED_BODY()
	
	UPROPERTY(EditAnywhere, BlueprintReadWrite)
	ESVMovementState MovementState;
};

In Chooser Table editor:

Look, I’m not sure what you are trying to do, all I know is you’d like to get the return data in C++, so there is a quick solution to achieve this, create a BlueprintImplementableEvent, that’s going to save you much time, since you can call this function in C++ and implement it in Blueprint, simple example:

.h file

UENUM(BlueprintType)
enum class ESVMovementState : uint8
{
	Idle,
	Walk,
	Run,
	Sprint
};

USTRUCT(BlueprintType)
struct FTraversalChooserIn
{
	GENERATED_BODY()

	UPROPERTY(EditAnywhere, BlueprintReadWrite)
	bool bIsMoving;
};

USTRUCT(BlueprintType)
struct FTraversalChooserOut
{
	GENERATED_BODY()
	
	UPROPERTY(EditAnywhere, BlueprintReadWrite)
	ESVMovementState MovementState;
};


UCLASS()
class DEV55_API ADevCharacter : public ACharacter
{
	GENERATED_BODY()

	UPROPERTY()
	FTraversalChooserOut OutData;
	
	UPROPERTY()
	FTraversalChooserIn InData;

public:
	
UFUNCTION(BlueprintImplementableEvent, Category = "Player|Anim")
	TArray<UAnimMontage*> CustomEvaluatedAnimMontage(FTraversalChooserIn InTraversal, FTraversalChooserOut& OutTraversal);
};

In Chooser Table:

In Your Blueprint override your custom function:

.cpp file - call your function:

InData.bIsMoving = true;

TArray<UAnimMontage> MontagesToPlay = CustomEvaluatedAnimMontage(InData, OutData);

May this solve your issue

Bye.

[InvQuasar]

At first I thought it would be better to do everything in code. But your solution seems more logical and convenient for me.
Thanks for your help!