I have been working on a water shader for my windows to make the hallway seem a bit more dynamic and believable
This is still a wip, and I would probably need to add some sort of condensation on the inside of the windows.
Here is how I managed to do this effect.
What I basically did was get two different water droplet textures, I got a reference off google, put it into photoshop and painted white on the water drop lets, made the texture seamless, then created a normal map out of the white/black texture mask.
I then went into UE4 and created several nodes, the most important nodes would of been the time, and panner nodes, these made the water fall down and different times since I had two variations of water drop lets.