I posted this a few years back on here and it got tagged as a duplicate and rolled into a request thread about a multi-layer shader. But, this is different. It could be an extra option in the multi-layer shader. This is from the old thread:
Hi, long-term Vray user who's been testing Corona for the last few days. Wow! It is fantastic and no doubt the future is bright.
I would like to see some kind of Utility material. MentalRay had one(before Adesk in it's wisdom decided to remove it for absolutely no reason)
Vray had the feature somewhat implemented recently with its VrayBumpMtl.
And there is also a Blur plugin material that I've been using. It's simply called Utility Material.
This blur plugin is the definitely the most feature packed of the three.
and this is an old image explaining what it does:
