Hi people!

I am working with a fluid emitter to create smoke.

This is what I got after lots of testing to achieve the density and movement that I needed.
see attached files p1

But there is one thing I can not get: the way the smoke appears. I need it to start very thin and get thicker after a while, like this

see attached files p2

I have tried using a polygon to shape it somehow, but I think its not possible in that way.

Any ideas?