Eevee cloud test

Decided to play with clouds in Eevee, after a conversation with @rogper. I have a lot to learn to effectively use Eevee!


Even so… Man! These look gorgeous! You can see my best results here, right in the first images.
I have so many questions!
…Main one how did you manage to have the clouds tinted like the sky!? I can only paint the clouds, I use a UV mapped texture to hand paint the clouds volume cube that then also affects the clouds… and that’s pretty much it! But in here, if you’re also doing something similar… I can’t figure it out and looks way more natural.
These actually look real good already :smiley: Any Eevee doubpt I’ll be here to help, been using it since the first builds were lunched and made more than 10 complete short animations with it.

I suspect the ‘tricks’ I employed here would not work well with other non-cloud things in the scene. But I haven’t tried either…
For the volume shaders, I went with two Volume Scatter nodes and a Volume absorption node, all added together. The first scatter had a high positive anisotropy, while the second had a high negative anisotropy. Splitting it into three volume nodes, rather than a single principled node, allowed for each of these to be controlled wrt color and density. Unlike cycles, the clouds will not fill in with color from the sky (at least they didn’t for me!), so this had to be faked by adjusting the colors by hand.
For the lighting, I used three sun lamps, each with a different direction, color, and strength. Additionally, there are two point lights acting as the sun at the bottom-center of the image. One more yellow, one more orange.
As for UV maps, I avoid them whenever possible! Partly because I am procedurally inclined, and partly because I haven’t yet learned to work with them properly. If the built-in unwrapping doesn’t work well, I don’t try to take it any farther. Some day I’ll buckle down and make myself learn the art of UV magic, but not today :).
Hopefully some of that is helpful for you. The machine I’m primarily using right now really struggles with eevee, but I have another with a decent video card. So I may try to make a scene with buildings and such to see about lighting clouds when there are other elements to consider.
Also, if you haven’t seen it, @Pixelshatter has a cloud node available for download here, and it is supposed to work well with eevee now. These clouds here don’t use it, but I’ve played with it a little and I think it could be quite useful.

Hello @Steah!
Thank you very much for your clear explanation!
I’m using the principled node alone indeed… I like your approach of using three difference shaders! At least with only the Principled ain’t working awesomely, so I need to try something else and your results are much better :slight_smile:

  • Memory limits may be the cause of slowdowns:
    Regarding the PC struggle with me happens the opposite, Eevee renders almost real time, up to volume grids of 8, still good at 4 and indeed slow at 2… but on Cycles it makes a 2 minutes render take 2+ hours :persevere: I have an 6 years old Titan X card with 12Gb of ram do… the current Eevee clouds drain a lot of memory! I suspect that is the origin of your performance issues. For example on the island image, it goes from 8Gb without clouds to 12Gb+ with clouds, this at 4K.

  • UV mapping:
    About the UV project, for this case, after entering in edit mode and from Top View I’ve used just the U -> Project from View. This projects the map as a 2D Square, so it’s easier to paint, but you can do the auto-unwrap or even the default one that comes with the cube to paint all around… it’s probably a good way to use different colors for top and bottom too.

I did knew about the @Pixelshatter clouds, they were what made me trust that it was possible :slight_smile: but I’ve missed this 2.8 update you’re showing now, thanks for the heads up!

All right! As soon I have improvements I’ll mention you if you don’t mind :slight_smile:
Anything I’ll be around!

I grabbed a CC0 medieval house by Daniel Andersson and Hreikin from 2014 so I could see about setting up lighting that would work for clouds without wrecking a scene. Looks like it is quite possible :). The clouds are based on Pixelshatter’s ProceduralCloudscape v0.4.

This render will certainly never win any awards, it was just to demonstrate the feasibility of something I hadn’t yet tried. A proper sky background gradient would really help as well, as this flat blue world is pretty terrible.
The Volumetric Samples in render settings has a huge impact on the results. Here it is 16, because that is what I balanced the cloud shader and lighting with. Turning it up to 256 would likely give better results, but everything will have to be rebalanced (and it runs so much slower with higher samples).
Here’s the blend file if you want to poke at it : basic houses with pixelshaders (4.9 MB)

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Hey @Steah!
Thank you very much for this demo! I’ve gave it a close inspections and I’ve determined that my bigger issue on Resilience Satelle is the volumetric start and end values :neutral_face:

So, I’ve replaced your scene with similar light from RS and this was the result (same thing as you, 100 to 300 meters range, just using Real-Sky lights):

Then I’ve started playing with the range and set it up from a 10 to 300 meters and finally the RS world range 10 to 22000 meters:

As you can see, on such a big range, the volumetrics just become some kind of mist that becomes very hard to get any vibrant light what so ever :thinking:

Also the densities have to go real down, on my clouds on 10 by 10 meters cube I can have densities of Value: 3.0 and they look gorgeous!
This is how they look on a 10 by 10 meters cube, very controllable and gorgeous, I can do anything with these clouds, I’m using an hand painted map to give them any color I want:

And the exact same thing (It’s an instance of the first one) but scaled up to a 1000 by 1000 meters domain:

So, to bring it to usable results, I need to lower the clouds densities to Value: 0.2:

…But then, as you can see, all the vibrant color that they had on the 10 by 10 meters cube, gets all washed up on the 1000 by 1000 meters one :sob: If I increase just a bit more the density it explodes again to the above look. This is at the very frontier of happening.

So my biggest issue with Eevee clouds is that they don’t appear to work for big landscapes and the Resilience Satelle main island has 1200 by 1200 meters and the entire world 40000 by 40000 meters.

Also important, the volumes, as far I know, don’t cast shadows.

Looking forward to seeing how you make out with the volume->mesh results. I played with it a bit today, but only managed to make cartoony clouds with surface shaders. The meshes looked better than expected, and with a volume shader they worked alright. But due to the limitations you’ve mentioned above, I suspect you’ll want to use a surface shader rather than a volume.

Yeah! To use the mesh I would discard completely the volumes and use just a simple surface shader. Eevee, as far as I know, can’t use any shape except a cube anyway, can it?

As you say they look cartoon… which for RS could work, but the biggest issue here is that one of the characters will be at clouds level, “surfing” by them, so, perhaps using the displace modifier to give the clouds some motion… :thinking: … I’m sure that there is a solution, perhaps even mixing geometry clouds for the big masses, with VDBs, just for some cloud feeling when up close… I’ll put all my research and development department working on this… which in this case is a full team of only me :joy: