How to achieve a illuminated rain effect?

Hi everyone !

I’m fighting with an effect I would like to achieve using particles & Blender (if possible Eevee, for rendering time concerns).

I want to make rain INSIDE a box, and to light that rain.

The lighting is very important. You should really understand were the light source is, by watching the rain. But the light itself doesn’t really show up. I did a lot of tests with particles, materials, volumetrics, etc; but can’t get close to it:

I also had tests with particles emitting light, the problem being that I really need water drops to be illuminated realisticly - and to react to my light setup as I update it.

Does anyone know how to do this (and if it is doable) ? Here’s my current blend file: https://www.dropbox.com/s/xjc6yrcvwx7nmce/testHouse012.blend?dl=1.

Thanks a lot for any help you might provide !

It’s better if you model the rain drops with ‘motion blur’ applied… And in this situation, you can also replace the reflections/refractions (glass) of the droplets material, with a simple diffuse/translucent mix.

I would also lower the shutter speed, maybe around 0.2-0.25? The streaks in the original are fairly short.

Yeah, that is a problem. Because in real life they don’t do it realistically - when they really want to show the rain. There is always backlight, usually motivated by a practical. And usually it is shot at night.

But your scene (rain) is frontlit. That’s a huge problem. Secrop is right, diffuse and translucency will mix both together and provide for both front and backlight. But you won’t get the specular focused stuff you get from a strong backlight.

So I tried cheesing it with the light falloff node, but gave up. Since not all drops will catch that “backlight” (which we are now faking) equally, I ended up with a 4 x particle info/random + 1 (from white to 5 x white) and fed those into diffuse and translucent color which was added together. It also went into a transparent shader I mixed in in the end.

Yeah, nothing conserving about this, but it kinda worked.