How to Run an Existing Game Inside of Unreal Engine

i don’t think this is reasonably feasible. it sounds like what you’re trying to do is have an overlay on top of an existing game but have all controls passed through. look at programs like nvida shadowplay, xfire, or the steam overlay. i’m sure there are others. maybe look at DX hooking programs like ninja ripper.

if you were to do this using UE4 you would need to run the program in the background, get it into unreal (you’d need a separate program for this and it would introduce lag, particularly bad for VR), you would need unreal to render your added elements on top of the program and receive input, and lastly pass that input back to the original program. this is inefficient, introduces lag, and would have to work with each program you needed. this would be a big project without trying to use UE4 and i’m pretty sure that you would have to write custom UE4 C++ libraries to do it; you might as well write those libraries as a separate program.


Be able to add an overlay (a webcam feed with greenscreen processing) to an existing VR capable flight simulator so that the user can see their physical controls and the sim utilizing green screen tech.


I need a way to run a flight simulator (XPlane, MSFSX, etc) within Unreal Engine 4. Any advice/direction is greatly appreciated. Also a solution that doesn’t involve using Unreal is also valid, but I prefer to stick with Unreal.

What I Have So Far

I currently have a way to display a webcam stream on a plane surface in Unreal with the green screen processing occurring in a blueprint.

Ideas/Examples That I Would Need Advice On
-Running the flight simulator directly


~Working Example in UE4 (

-Running the simulator on a monitor and using some form of screen cast software to send to Unreal

-Using an existing free flight simulator UE4 project (not prefered)