How to round edges of particular faces where I have assigned emission material? hope you have a good day. I've stumbled upon a very specific problem, so hopefully, some of you will know the solution to this.



As you can see, I have selected faces of my model, to which I've assigned Emissive material through combination of nodes. 



Well, I'm sure now you can easily see where this is going. The faces, which have the emissive material assigned, look pixelated and blocky. I have already searched for some solutions to this online, but haven't found any.

What I'm trying to achieve is to make these particular faces look less pixelated and more smooth. I know it can be achieved by rounding the outer edges of selection, but I don't know the workflow to this.

And yes - I have already tried beveling, only to find out it isn't of any use. I also tried to transform the outermost edges "To Sphere", but it didn't work either. How can this be done then? Thanks everyone in advance.
Better if you use a mix shader with a mask, instead of this method. Of course you can paint the emission pattern if you have a UV map.