Unless it already exists, it would be cool to use effects like Vray impacting scene realism.
scene.render(effectID)
is Post Processes what you are looking for?
I guess both, giving a vray feel for realism… 
Then we will raise the next issue: How to make V-Ray render more realistic? (popular Google query).
Another thing is that Babylon is real-time rendering engine. Vray supports photoreal rendering but not in real time.
I think you should rename the feature request to Ray Tracing ?
To better describe what i mean: imagine reviewing your final scene - and then applying a scene filter / preset that illuminates the scene giving it special realistic effects - see images.
This does a similar job via multiple settings : https://playground.babylonjs.com/#Y3C0HQ#146
