立即修改:

MyCharacter->SetActorRotation(FRotator(0.f, 180.f, 0.f));

平滑修改:

void TickFun()
{
    FVector MyLoc = MyCharacter->GetActorLocation();
    FVector TargetLoc = FVector(100.f, 100.f, 0.f);
    FVector Dir = (TargetLoc - MyLoc);
    Dir.Normalize();
    MyCharacter->SetActorRotation(FMath::Lerp(MyCharacter->GetActorRotation(), Dir.Rotation(), 0.05f));
}

参考自:https://answers.unrealengine.com/questions/223469/smoothly-rotate-object.html