Saving event display with event

Dear ROOTers
I would like to save EventDisplay. Currently I have TEveViewer that contains event scene and geometry scene. However when I try to save GLViewer from this object I have only geometry.
I was trying to add scene to this GLViewer but I obtain warning “Warning in TGLViewerBase::AddScene: scene ‘Event scene’ already in the list.”.

What do you mean exactly by “Save” ?

I would save this as image (png/gif). Fortunately I noticed that calling gEve->FullRedraw helps. But I still don’t know why in my ED gEve->Redraw is enough to refresh picture that is visible on screen but not enough to refresh picture that will be saved as image.