Creating and using a blendspace in c++

转自：https://forums.unrealengine.com/development-discussion/c-gameplay-programming/104831-creating-and-using-a-blendspace-in-c

creating and using a blendspace in c++

12-23-2016, 07:09 PM

 

Hello all,

i'm trying to automatize the animation of (a lot of) pawns and would like not to have to define ~100 blendspaces and animblueprint by hand in the editor.

If i can get it to work, i'll just have to create blueprints inheriting from this class and set the skeletal mesh and animations.

This subject seems to pop up every now and then, there are a few post on the answerhub, and even a wiki by Rama, but all of them seem to assume that the BlendSpace is created in the editor.

As you can see, i'm trying several methods (via the skeletal mesh component and the anim instance) to animate the mesh with the blendspace, none of them works so far.
I tried everything i could find related to animation and blendspace in the api documentation.

I can spawn the blueprint, but the mesh remains static so obviously i miss something.

I tried to set this in the blueprint, and i can see the debuging flow correctly going through everything.

I can't check visually the blendspace, so i'm a bit lost and dry now.

Here's the code:

void AYagPawn::BeginPlay()
{
    Super::BeginPlay();
    
    [...]

    // creating the BS (SMC_00 is a USkeletalMeshComponent)
    ThisBlendSpace1D = NewObject<UBlendSpace1D>(this, UBlendSpace1D::StaticClass());
    ThisBlendSpace1D->SetSkeleton(SMC_00->SkeletalMesh->Skeleton);

    // setting a parameter for the BS
    FBlendParameter BP_Speed;
    BP_Speed.DisplayName = "Speed";
    BP_Speed.GridNum = 4;
    BP_Speed.Min = 0.f;
    BP_Speed.Max = 100.f;
    ThisBlendSpace1D->UpdateParameter(0, BP_Speed);

    // adding two sample (at 0 and 100)
    // IdleSequence and MoveSequence are UAnimSequence to be set in the BP inheriting this pawn class
    FBlendSample IdleSample = FBlendSample(IdleSequence, FVector(0.f, 0.f, 0.f), false);
    FBlendSample MoveSample = FBlendSample(MoveSequence, FVector(100.f, 0.f, 0.f), false);
    ThisBlendSpace1D->AddSample(IdleSample);
    ThisBlendSpace1D->AddSample(MoveSample);

    // first method 
    SMC_00->PlayAnimation(ThisBlendSpace1D, true);

    // second method
    SMC_00->SetAnimation(ThisBlendSpace1D);
    SMC_00->Play(true);

    // third method
    SMC_00->OverrideAnimationData(ThisBlendSpace1D, true, true, 0.f, 1.f);

    // fourth method
    BS_AnimInstance = Cast<UAnimSingleNodeInstance>(SMC_00->GetAnimInstance());
    BS_AnimInstance->SetAnimationAsset(ThisBlendSpace1D);
    BS_AnimInstance->PlayAnim(true, 1.f, 0.f);
}


void AYagPawn::Tick( float DeltaSeconds)
{
    Super::Tick(DeltaSeconds);

    [...]

    // update BS with Speed (a float)
    BS_AnimInstance->SetBlendSpaceInput(FVector(Speed, 0.f, 0.f));

    // useless in principle but i tried
    SMC_00->OverrideAnimationData(ThisBlendSpace1D, true, true, 0.f, 1.f);
}

And here is the variables section in the BP:

As you can see, the BS is still empty (normal, it will be created in the begin play function at runtime) and both animations have default values.

Any idea ?

Thanks

Cedric

EDIT: i realized i wasn't setting the animation mode, so i added this in the constructor:

Code:

SMC_00->SetAnimationMode(EAnimationMode::AnimationSingleNode);

But it still doesn't work.

Answers:

Edit: I should have read your entire question. I'm interested in this so I'm going to help you get the bottom of it! You're probably missing an update call somewhere, or you need to serialize the result to an asset or something. I'll report back.

Here's a compiled simple animation blueprint. It uses a blendspace called "Strafe_IP" and has two variables: Right, Forward. Note that the Character class doesn't appear to call or update the animation - it only sets it initially.

Code:

UCLASS(config=Engine, Blueprintable, BlueprintType, meta=(ReplaceConverted="/Game/Blueprints/BPA_Test.BPA_Test_C", OverrideNativeName="BPA_Test_C"))
class UBPA_Test : public UAnimInstance
{
public:
    GENERATED_BODY()
    
    UPROPERTY(meta=(OverrideNativeName="AnimGraphNode_Root_6D3BF226443B80030387A5AADD092A5D"))
    FAnimNode_Root Root;
    
    UPROPERTY(meta=(OverrideNativeName="AnimGraphNode_BlendSpacePlayer_44691A814B28B34EF79F7B8F71402E07"))
    FAnimNode_BlendSpacePlayer BlendSpacePlayer;
    
    UPROPERTY(EditDefaultsOnly, BlueprintReadWrite, meta=(DisplayName="Right", Category="Default", OverrideNativeName="Right"))
    float Right;
    
    UPROPERTY(EditDefaultsOnly, BlueprintReadWrite, meta=(DisplayName="Forward", Category="Default", OverrideNativeName="Forward"))
    float Forward;
    
    UBPA_Test(const FObjectInitializer& ObjectInitializer = FObjectInitializer::Get());
    static void __CustomDynamicClassInitialization(UDynamicClass* InDynamicClass);
    static void __StaticDependencies_CommonAssets(TArray<FBlueprintDependencyData>& AssetsToLoad);
};

UBPA_Test::UBPA_Test(const FObjectInitializer& ObjectInitializer) : Super()
{
    if(HasAnyFlags(RF_ClassDefaultObject) && (UBPA_Test::StaticClass() == GetClass()))
        UBPA_Test::__CustomDynamicClassInitialization(CastChecked<UDynamicClass>(GetClass()));

    Root.Result.LinkID = 1;
    BlendSpacePlayer.BlendSpace = CastChecked<UBlendSpaceBase>(CastChecked<UDynamicClass>(UBPA_Test::StaticClass())->UsedAssets[0], ECastCheckedType::NullAllowed);
    BlendSpacePlayer.EvaluateGraphExposedInputs.CopyRecords = TArray<FExposedValueCopyRecord> ();
    BlendSpacePlayer.EvaluateGraphExposedInputs.CopyRecords.AddUninitialized(2);
    FExposedValueCopyRecord::StaticStruct()->InitializeStruct(BlendSpacePlayer.EvaluateGraphExposedInputs.CopyRecords.GetData(), 2);
    
    auto& _Right = BlendSpacePlayer.EvaluateGraphExposedInputs.CopyRecords[0];
    _Right.SourcePropertyName = FName(TEXT("Right"));
    _Right.DestProperty = FindFieldChecked<UFloatProperty>(FAnimNode_BlendSpacePlayer::StaticStruct(), TEXT("X"));
    _Right.Size = 4;
    
    auto& _Forward = BlendSpacePlayer.EvaluateGraphExposedInputs.CopyRecords[1];
    _Forward.SourcePropertyName = FName(TEXT("Forward"));
    _Forward.DestProperty = FindFieldChecked<UFloatProperty>(FAnimNode_BlendSpacePlayer::StaticStruct(), TEXT("Y"));
    _Forward.Size = 4;
    
    Right = 0.000000f;
    Forward = 0.000000f;
}

void UBPA_Test::__CustomDynamicClassInitialization(UDynamicClass* InDynamicClass)
{
    ensure(0 == InDynamicClass->ReferencedConvertedFields.Num());
    ensure(0 == InDynamicClass->MiscConvertedSubobjects.Num());
    ensure(0 == InDynamicClass->DynamicBindingObjects.Num());
    ensure(0 == InDynamicClass->ComponentTemplates.Num());
    ensure(0 == InDynamicClass->Timelines.Num());
    ensure(nullptr == InDynamicClass->AnimClassImplementation);
    
    InDynamicClass->AssembleReferenceTokenStream();
    FConvertedBlueprintsDependencies::FillUsedAssetsInDynamicClass(InDynamicClass, &__StaticDependencies_DirectlyUsedAssets);
    
    auto AnimClassData = NewObject<UAnimClassData>(InDynamicClass, TEXT("AnimClassData"));
    AnimClassData->TargetSkeleton = CastChecked<USkeleton>(CastChecked<UDynamicClass>(UBPA_Test::StaticClass())->UsedAssets[1], ECastCheckedType::NullAllowed);
    AnimClassData->RootAnimNodeIndex = 1;
    AnimClassData->RootAnimNodeProperty = InDynamicClass->FindStructPropertyChecked(TEXT("Root"));
    AnimClassData->AnimNodeProperties = TArray<UStructProperty*> ();
    AnimClassData->AnimNodeProperties.Reserve(2);
    AnimClassData->AnimNodeProperties.Add(InDynamicClass->FindStructPropertyChecked(TEXT("Root")));
    AnimClassData->AnimNodeProperties.Add(InDynamicClass->FindStructPropertyChecked(TEXT("BlendSpacePlayer")));
    InDynamicClass->AnimClassImplementation = AnimClassData;
}

void UBPA_Test::__StaticDependencies_CommonAssets(TArray<FBlueprintDependencyData>& AssetsToLoad)
{
    const TCHAR* __Local__3 = TEXT("/Game/MovementAnimsetPro/BlendSpaces");
    const TCHAR* __Local__4 = TEXT("/Game/Mannequin/Character/Mesh");
    FBlueprintDependencyData LocAssets[] =
    {
        FBlueprintDependencyData(__Local__3, TEXT("Strafe_IP"), TEXT("Strafe_IP"), TEXT("/Script/Engine"), TEXT("BlendSpace")),
        FBlueprintDependencyData(__Local__4, TEXT("UE4_Mannequin_Skeleton"), TEXT("UE4_Mannequin_Skeleton"), TEXT("/Script/Engine"), TEXT("Skeleton")),
    };
    for(auto& LocAsset : LocAssets) { AssetsToLoad.Add(LocAsset); } 
}

struct FRegisterHelper__UBPA_Test
{
    FRegisterHelper__UBPA_Test()
    {
        FConvertedBlueprintsDependencies::Get().RegisterClass(TEXT("/Game/Blueprints/BPA_Test"), &UBPA_Test::__StaticDependenciesAssets);
    }
    static FRegisterHelper__UBPA_Test Instance;
};

FRegisterHelper__UBPA_Test FRegisterHelper__UBPA_Test::Instance;