I’ve shown one technique for water droplets in the past by using Forest Pro. It’s a good method, but recently I had a chance to develop a different approach – this one is strictly shader-based. No fancy geometry scattering required.
We only need to create 2 maps for this shader – a normal map for the droplets and a mask for the foggy part of the condensation. The maps are closely related, so they are created in the same photoshop file.
To get started we need a height map of a droplet. Sure, you can mess around with gradient tool in photoshop to get something approximately like we need, but in my opinion the best way is to simply model a single droplet in 3ds max and render out it’s zdepth pass. This imho is the easiest way to get a perfect displacement/normal map.
Now the second step is creating the actual maps we will use for our shader. This is the longest and most difficult part of the process. It can be kind of fun though, it’s a chance to be creative.
In the next video I’ll show you how I approach this process in photoshop, I hope you’ll pick up some useful tricks :)
I rushed the process a bit for the tutorial, but you can take as long as you need to get the maps perfect and tileable.
Finally, we need to set up the actual Vray shader, it’s actually the easiest part of the process. Watch the video to see how to do it!
As you can see, there’s more than one way to skin the cat.