2.5D platformer how to darken building edges?

2.5D platformer how to darken building edges?

I was wondering how I could go about creating a vignette type effect / some sort of volumetric shadow for the 'cross section' parts of a 2.5D level. The effect I'm going for can be seen in 'This war of mine' where the edges of the rooms and walls / floors that are facing the camera have been darkened and blurred. (see below).  

I thought about creating the edges in photoshop and then blurring them and putting them in, however the blur scales weirdly as I'm re scaling the sprites so it looks really fake and not like a visual effect. Is there perhaps a 2d shader I could use or make? 
Any help on this would be appreciated!
Cheers
My photoshop attempt to recreate

Solutions/Answers:

Answer 1:

The effect you are looking for is easily archieved with the help of the Post Processing Stack available on the asset store for free and owned by Unity Technologies. You can also create other effects using this as well with lots of tutorials around the web. An example with and without post procesing from the asset store:
An example with and without post processing

An vignette type effect is also available the post processing script.

Answer 2:

You could implement a cross section shader but if you are not going to move the cross sectional plane then this would be a waste of time.

I believe the solution for TWOM was simply to overlay some black bars with rough edges a cutout/transparent shader.

References