Custom Movement Component crashing

Development Programming & Scripting C++
,
1

I have a custom movement component that I’m using with a custom character. My custom movement component is like this:

UCLASS()
class UBreakdanceMovementComponent : public UCharacterMovementComponent
{ ...

And my character class has a constructor like this:

ABBoyCharacter::ABBoyCharacter(const FObjectInitializer& ObjectInitializer)
: Super(ObjectInitializer.SetDefaultSubobjectClass<UBreakdanceMovementComponent>(ACharacter::CharacterMovementComponentName))
{
	UBreakdanceMovementComponent* movement = GetCharacterMovement<UBreakdanceMovementComponent>();
	movement->CreateCardboard(FVector(5,5,1));
	...

This works fine, I can use GetCharacterMovement in the constructor and it’s the right type of class. But I also have an input action bound to a key, and when I call it there it crashes because the cast is saying it’s a normal UCharacterMovementComponent, not my custom class. Ie, in the input function:

void ABBoyCharacter::Spin(const FInputActionValue& Value)
{
	UBreakdanceMovementComponent* movement = GetCharacterMovement<UBreakdanceMovementComponent>();
	if(movement->HasCardboard())
	...

That same typecasted call to GetCharacterMovement fails even though it worked fine in the constructor.

What?? Why?

2

Try this

3

That has the exact same problem. The typecast version of GetCharacterMovement uses CastChecked.

4

Ah. It’s because this is the main pawn from the template project, which instantiates a blueprint class (BP_ThirdPersonCharacter). I had to open that blueprint, open the full view, select the Character Movement Component, and set its “Component Class” to my custom class. Compile & Save that and everything works as expected.

Also worth noting that I’ve now created a new data-only blueprint inheriting from the custom character and it assigned that movement component automatically, which is better. This feels like something the engine didn’t update behind the scenes properly…

1 Like
5

why would you expect it to automatically change an already existing blueprint’s components without asking it to?