Help with glass that has variations across it

Hi!

I’m trying to figure out a way to have variations of roughness or something like that across a plane (or in my case curved) piece of glass. I want to be able to see through parts of it more clearly than others but am kind of stuck figuring out how to go about it.

In the same vain but a little different, I’d like to create say someones breathe fogging up one part of the glass near where their mouth is. Anyone have ideas on how to achieve this?

Thanks!

for the second mat for breathe
select some round faces and make it another mat and use higher roughness!

happy cycles

Make grayscale image of this ‘fogging’ and apply image as a value for roughness for the material. If that’s for cycles.

ahhh, great! Thanks so much! I’ll hopefully get a chance to investigate this tonight.

eppo, how would I go about doing that? I’ve tried a few different node set ups but none of them seem to work.

There is an example. Such wetness on the glass is better seen on a dark background, as if you looked out in the night from the lit room and differences between rough and smooth surfaces changes depending on angle you look at it.
If that is some closeup you could setup particle system, density of which is driven by the same texture.


Hope helps.