This is on HD 1920*1080.
Looks exactly the same on UHD 4K.
I didnt realy think it was a resolution problem though, seems like the options inside the Cloud Layer Override dont fix it either, only thing I can think of is using a different CloudMap Texture as the input. This is the default texture in HDRP : DefaultCloudMap
Is there a workflow to make our own CloudMap Texture? Or how can I make my own/improve the default one?
Or am I missing an option somewhere that bounces up the fidelity?
Other than increasing the sampling for the layers you can also increase the two flare properties on the directional light, having a much higher amount like 64 and 512 can alleviate it.
Regarding creating you own you can yes, but you will likely have to do it externally, and you would still get this effect as based around the light loop more so than just the cloud.
I also found making the clouds a bit more transparent (.98f-.99f) also helps, but it makes it so the clouds will never completely block out the sun which doesnt make it the best solution.
You can increase the resolution by right clicking on the override in your volume profile, selecting “show additional properties”, and then enable the new “resolution” property and setting it to something higher than the default “Cloud Resolution 1024”.
The texture itself is actually a 2k texture, but the sampling will look better if you increase the cloud resolution to 4k or even 8k.