Hi
I have been playing around with UEFN Post Process volumes and finding the system really frustrating.
Hoping we have someone that is really confident with PP and UEFN that could either explain if I am doing things wrong or show how to get some of these effects from packs working in UEFN
So it appears these are the basic effects we get & we have the Post Process Device which I am not going to use at this point.
Having paid for some rather nice PP Effects from Marketplace FAB it is a mixed bag some work some don’t - this at first seems more to do with low end devices not been able to handle certain effects until you delve further into the insanity 
(will post about this further down)
So with these PP Effects I purchased it is possible to simply create a PP Volume and in the Array option we can link the PP Effect to the Volume (nice and easy) when the player enters this volume the effects work - there are issues if different effects & volumes cross into one another so options to blend or set priorities can be used.
So here is the first question, I want to use the UEFN PP Effects in a similar way with a volume not going through the PP Device
Finding the effects in the image above we can drag them into our map but not seeing PP Options so I right clicked on Retro and created a new blueprint class based on this
I then unticked Unbound so this effect only works if the player enters the volume, all appears to be good until I launch the map.
You can see the effect working on entering the volume yet this flags up on validation saying
Found disallowed object type /ScriptEngine.InheritableComponentHandler, Referenced by: See below for Asset list, Plugin mount point: /RedVsBlueWarehouse.
/RedVsBlueWarehouse/PP_Retro_Child
So that looks like we can only use the PP Effects that come with UEFN if we go through the PP Device?
So this brings me to the 2nd Question
In this pack I purchased it has Night Vision / Thermal / Xray and many other effects but none of these work - images in the editor pre-launch.
I even followed a tutorial on YouTube as well as purchased a second pack from FAB to try and use Thermal (via a PP volume box)
The frustrating thing is we have the Thermal Fish and we have some weapons that have thermal vision and UEFN has it’s own Thermal and Night Vision PP Effects providing we use the PP Device so it seems wrong that these same effects from Marketplace / FAB can not be used in our maps - why is this?
So here I went through Volumes - Post Process Volume - dragged the volume into the map, you can see the Thermal Effect
I then went to Array - Element and linked the Thermal Material from one of the packs
With an effect called Toon, one that looks like a painting effect, some underwater effects, the Xray Thermal and Night Vision + others they all give this same error
Am I correct in thinking that certain devices are holding things back, if so is there a way to bypass those devices so the effects would work but not on say Switch or low end mobiles etc?
The night vision image above I used the PP Device connected to the PP Volume - I had Unbound box Un-Ticked so thought the player would have to go into the box to see the effect but it showed over the whole map so unsure if this is a bug or if I am doing something wrong?
This video shows All the PP Effects most of these we can only access through using the PP Device
So the thermal taffy fish gives that effect above, there are also
this night hawk weapon gives off the thermal effect when looking down the sights as do some other weapons
I am guessing this effect works on low end devices too so why isn’t thermal PP allowed from outside the game?
That was the tutorial I went through which got errors due to low end devices
There are several ways to add PP volumes
1 Quickly add to the project - Visual Effects - Post process volume
2 Quickly add to the project - Volumes - Post process volume
3 Quickly add to the project - Place actors Panel (from menu) drag Vfx or Volume - PP Volume into map.
Either use Array - add custom PP Materials or use PP Device