Spawned Actor getting weird Transform Values

Development Programming & Scripting
1

Hi!

I’m trying to spawn e.g. a directional light:

ADirectionalLight* DirectionalLight = (ADirectionalLight*)GetWorld()->SpawnActor(ADirectionalLight::StaticClass(), &FVector::ZeroVector, &FRotator::ZeroRotator);

The spawned actor already has a pitch value of -46 degrees, even though I spawned it with a zero rotator (not attaching it to any other actor). If I actually specify a rotator for SpawnActor(), t gives me even weirder values. Like, using

FRotator DirectionalLightSpawnRotation(100.f, 5.f, -30.f);

results in a rotation of (8, 82, 41) in the game. Also: the light has a scale of (2.5, 2.5, 2.5) when spawning, but I didn’t even specify a scale in SpawnActor().

I’m having these problems with ALL my actors, but some at least have the proper (1, 1, 1) scale. This even happens when I use the Spawn Actor From Class node in a blueprint, spawning a totally different class! Only when I drag&drop an actor into the level and specify the transform values manually, they are kept that way in PIE. So, is this a bug somehow nobody ever has stumbled upon, or what am I doing wrong / don’t understand here?

BTW, why is the order Pitch->Yaw->Roll in the C++ constructor, but Roll->Pitch->Yaw in the details panel? Always confuses me.

Thanks!

2

Found the reason why this happens. Some of the built-in actors have components with default rotation/scale. Because you can only see the root component transform in the actor’s details panel, when spawning an actor with (0,0,0) rotation that has its root component with (-46,0,0) as is the case with directional lights, you’ll still only see (-46,0,0) there, even if the actor itself has no rotation at all. So, one solution for this would be to change the component transform directly and keep the actor transform at default.

3

Exactly. Therefore it’s advisable to leave the root component’s scale at 1.0.

Curiously, many Unreal Engine sample projects don’t do that…