Need Help on creating a seamless transition between two environments

Hi Everyone!

I am working on a VR project similar to this

What i want is when i start moving my head from front to the back the environment (snowy one) starts to fade and slowly transitioned into some other environment. Vice versa when moving head from back to front.

I tried finding some references from games and movies. This is the closest one that i found from Constantine.

Please guide me about all the possible ways to achieve this transitioning effect between two environments.

 

i would use the rotation and apply that towards fade in values for each.
like if your rotated 0 degrees then 1 part is at 100% transparency and the other is at 0%
then as the rotation increases one goes up and the other goes down until you are at 180 and then you would have 0% and 100% respectively.