I'm trying to render a scene where the camera is behind a window, on the other side there's a light-emitting background image (image on a plane), and there are some rain drops on the outside of the window. For the rain, I have heightmaps defining the structure. The scene without the rain looks like this:
I'm not really familiar with blender so I'm not sure what the best way to go about rendering the rain heightmap. I've tried making a mesh from the heightmap and setting the material to something water-like, and putting this on top of the window but that doesn't work. I've also read that normal maps are better for texture so I think I should be using that instead? Which has led me to think I should make some kind of plane with a water-like material, then add a texture to it using a normal map that I bake from my heightmap?
Any advice on the general workflow I should go through would be greatly appreciated. I'm really trying to make this scene as realistic as possible so any tips on how to make the material and light refraction (going through the rain then the glass) realistic that would be super helpful.