SilverLining offers many alternatives for rendering dense clouds, ranging from particle-based dense CUMULUS_CONGESTUS cloud layers, to truly volumetric STRATOCUMULUS layers, to highly-efficient STRATOCUMULUS_PARTICLES layers, and finally the fastest option of all: the STRATUS cloud layer type.
STRATUS is a bit of an odd duck. It gets its speed from the fact that it’s basically a “texture sandwich” of two large, 2D polygons that represent the top and bottom of the cloud layer, with fog in between them. Some extremely sophisticated shaders make those textures look as realistic as possible, including effects such as fogbows and glories that just fall out of the math naturally.
However, the simplicity of their geometry can lead to some edge cases you might need to address.
Fix geometry gaps with stratus-flat-tops
SilverLining will attempt to create some 3D depth to the cloud tops, but it doesn’t have many vertices to work with in order to ensure good performance. In some configurations, this can lead to visible gaps in the cloud layer top. If you encounter this, the fix is simple: set stratus-flat-tops in the SilverLining.config file to “yes”.
Add extra resolution with stratus-grid-dimension-solid
If you don’t have gaps in a stratus layer with 100% coverage, but the tops of the clouds look like a bunch of pyramids – you may need more geometry resolution than what we provide by default. Try increasing stratus-grid-dimension-solid to, say, 1024 – and it should look better.
Adjust the overall brightness with stratus-deck-light-scale
An easy way to make the cloud brighter or darker to fit your taste is with the stratus-deck-light-scale parameter. There are many other parameters to affect the cloud lighting, but this is the only one that works in a straightforward way that won’t have side effects that you might not notice at first.
Make sure your layer size is large enough
In the real world, stratus cloud layer span large areas. The way we break down a stratus cloud’s geometry will start to break down if you try to set up a stratus cloud layer smaller than around 20km per side. The whole point of the STRATUS cloud type is to offer an efficient way to render very dense cloud layers out to very far distances, so take advantage of that capability. Stratus clouds look best with a width and height between 100,000 and 300,000 meters.