After playing a few rounds of insurgency and watching videos of insurgency sandstorm,I've been concerned over the FPS cost of 3d scopes. So I have this idea... (I've never made anything with UE4, but please bear with me)
When you use a 3d scope...anything outside of the scope can be rendered at a lower resolution or frame rate. I've read about a certain game engine rendering characters at a higher framerate compared to objects in the scene.
There can be new options in the video settings for 3d scopes.
*Scope resolution (low,med,high,adaptive)
"Outside the scope" settings:
*Reduce fps (limits the outside the scope framerate to 30,uses a blur effect to make transitions between frames look smoother,like far cry 4 does on the console)
*Resolution reduction (instead of just blurring whats outside your scope,you'll have the scene rendered at a lower resolution so long as you're using your 3d scopes.)
I hope something can be done about the 3d scopes being such performance hogs.
Some are experimenting with foviated rendering in VR (with eye tracking software). This works by rendering whatever the player is not looking at,at a lower resolution. Sometime similar should be done with objects outside of the scope,if such a thing is possible.