Capturing stereoscopic 360 from Unreal Engine 4

[Eldarele]

I had the same issue you have. After digging around I found this link:

SceneCaptureComponent GetViewState return NULL then Capture Picture...

It seems that when the bCaptureEveryFrame is set to false, which is the case when capturing stereoscope, it sets the viewstate to null. This disables the post processing volume. When changing the code in SceneCaptureComponent.cpp to:

 FSceneViewStateInterface* USceneCaptureComponent::GetViewState()
     {
         FSceneViewStateInterface* ViewStateInterface = ViewState.GetReference();
         if (ViewStateInterface == NULL)
         {
             ViewState.Allocate();
             ViewStateInterface = ViewState.GetReference();
         }
         return ViewStateInterface;
     }

You now force the viewstate to never be NULL, so now the post processing volume will work normally, including the blendable array.