update2 : My inablilty to get around these compiler linker errors has prevented me from implementing one of my game features and forced me to comment out about 2 hours of work, please let me know when this will be fully corrected, or if my build file is missing something or I’m missing a header or something like that 
PS: I am still absolutely loving UE4! Thank you so much for sharing it with me!
update: So I was all excited because I found a workaround to the problem below, by directly finding the UAtmosphericFogComponent in the world
//Retrieve the Atmosphere
TObjectIterator< UAtmosphericFogComponent > ActorItr2;
//set first found
if(ActorItr2)
{
Optimize("Atmosphere found!");
Atmosphere = *ActorItr2;
}
So I went to use SetSunMultiplier()
//Atmosphere
if(VictoryPC->Atmosphere)
VictoryPC->Atmosphere->SetSunMultiplier(
0.7//FMath::Lerp < float > (VictoryPC->Atmosphere-> SunMultiplier, 0.7, IntroZoomAlpha)
);
and once again
Got a linker error!
1>Module.VictoryGame.cpp.obj : error LNK2019: unresolved external symbol "public: void __cdecl UAtmosphericFogComponent::SetSunMultiplier(float)" (?SetSunMultiplier@UAtmosphericFogComponent@@QEAAXM@Z) referenced in function "public: void __cdecl AVictoryWarrior::IntroZoomIn(void)" (?IntroZoomIn@AVictoryWarrior@@QEAAXXZ)
1>E:\RocketVictory\VictoryGame\Binaries\Win64\RocketEditor-VictoryGame.dll : fatal error LNK1120: 1 unresolved externals
using
#include "EngineClasses.h"
did not change the compiler error
Please fix this, I cannot modify the atmosphere during runtime from C++
Dear Friends at Epic,
I am trying to retrieve the atmospheric fog actor for my level at runtime.
I can verify that there’s an actor in the world that contains the word “atmospheric” in it’s name, but that’s all
I cannot do the following:
AAtmosphericFog::StaticClass() <--- I get a compiler linker error
Cast(*ActorItr2); <---- Compiler linker error
TActorIterator< AAtmosphericFog > ActorItr2 = TActorIterator< AAtmosphericFog >(GetWorld());
TObjectIterator< AAtmosphericFog > ActorItr2; //<---- same linker error
The Compiler Linker Error
>
1>Module.VictoryGame.cpp.obj : error LNK2019: unresolved external symbol "public: static class UClass * __cdecl AAtmosphericFog::GetPrivateStaticClass(wchar_t const *)" (?GetPrivateStaticClass@AAtmosphericFog@@SAPEAVUClass@@PEB_W@Z) referenced in function "public: __cdecl TObjectIterator::TObjectIterator(bool)" (??0?$TObjectIterator@VAAtmosphericFog@@@@QEAA@_N@Z)
1>E:\RocketVictory\VictoryGame\Binaries\Win64\RocketEditor-VictoryGame.dll : fatal error LNK1120: 1 unresolved externals
1>
This part is of great interest to me, I cant do much about this, I hope you can
unresolved external symbol "public: static class UClass * __cdecl
AAtmosphericFog::GetPrivateStaticClass(wchar_t const *)"
From the code below I can only successfully verify that there is an actor in the world whose name contains “Atmospheric” but I cannot cast the actor that has this name for my future use
//Retrieve the Atmosphere
TObjectIterator< AActor > ActorItr2;
//set first found
while(ActorItr2)
{
//if (ActorItr2->IsA(AAtmosphericFog::StaticClass())) //<--- does not compile
//{
if(ActorItr2->GetName().Contains(TEXT("Atmospheric"))) //<--- this succeeds
{
Optimize("Atmosphere found!");
//Atmosphere = Cast(*ActorItr2); //<--- does not compile
break;
}
//}
++ActorItr2;
}
I am trying to cast to this class:
// Copyright 1998-2013 Epic Games, Inc. All Rights Reserved.
#include "AtmosphericFog.generated.h"
UCLASS(showcategories=(Movement, Rendering, "Transform|Actor"), ClassGroup=Fog, placeable)
class AAtmosphericFog : public AInfo
{
GENERATED_UCLASS_BODY()
UPROPERTY(BlueprintReadOnly, VisibleAnywhere, Category=Atmosphere)
TSubobjectPtr AtmosphericFogComponent;
#if WITH_EDITOR
void Spawned();
#endif
};
Please let me know what I can do to get the atmospheric fog actor so I can modify it during runtime
Rama