Problem with cull distance volumes and level streaming

Hey Mike,

Do you have the culling volumes located in your persistent level or in the sub-levels? In my research of your issue I found this post from Reddit that may help you:

https://www.reddit.com/r/unrealengine/comments/6ogklw/level_streaming_disables_precomputed_visibility/

You may just need to move your volumes to the persistent level. If that doesn't work, let me know and we can try something else!

After checking the source code, the problem is Cull Distance Volume being triggered only once to iterate all the actor which is visible when persistent level is loaded, this time streaming level may not loaded and being visible(in editor, the streaming level is already loaded and visible if you tick on the Initially Loaded and Initially visible, so it works fine)

the solution is add some tricks in source code

in the LevelTick.cpp, line 1654, customize the code below, and compile the engine

 #if WITH_EDITOR
     if(GIsEditor && bDoDelayedUpdateCullDistanceVolumes)
     {
         bDoDelayedUpdateCullDistanceVolumes = false;
         UpdateCullDistanceVolumes();
     }
 
     //My Custom Code Begin////////////////////////////////////////////////////////
 #else
 
     if (GWorld->HasBegunPlay() && !bDoDelayedUpdateCullDistanceVolumes)
     {
         bDoDelayedUpdateCullDistanceVolumes = true;
         const TArray<ULevelStreaming*>& StreamedLevels = GetWorld()->StreamingLevels;
 
         for (int32 LevelIndex = 0; LevelIndex < StreamedLevels.Num(); LevelIndex++)
         {
             // Update the level only if it is visible (or not a streamed level)
 
             if (!StreamedLevels[LevelIndex]->IsLevelVisible())
             {
                 //GEngine->AddOnScreenDebugMessage(-1, 60.0f, FColor::Yellow, StreamedLevels[LevelIndex]->GetName());
                 bDoDelayedUpdateCullDistanceVolumes = false;
             }
         }
 
         if (bDoDelayedUpdateCullDistanceVolumes == true)
         {
             UpdateCullDistanceVolumes();
         }
 
     }
 
     //My Custom Code End////////////////////////////////////////////////////
 #endif // WITH_EDITOR

One last note is about the Cull Distance value setup, the unreal unit is cm, but you may encounter the culling distance not match between PIE and play in packaged game, the problem is the CVar: r.ViewDistanceScale, when you are in Scalability 4, the r.ViewDistanceScale will automatic set to 10. This makes confusing at first if you don't know what is being control at background.