Simul Support ExchangeCategory: CloudsGraphic quality scalability
PrivateFox asked 3 years ago

Hello everyone
Is there a way how to increase performance and still have reasonably good looking clouds?
I know that lowering the “Cubemap resolution” value will increase performance drastically, but the sky isn’t really pretty. I would like to maintain the quality of the sky at least as at 512 resolution for most players. but the frame rate is then only at 10 fps. Although I don’t need such a high quality when developing in the editor, I still find the performance low in an empty scene.
I know I don’t have a hi-end graphics card, but I have some games with TrueSky and the quality of the clouds is very good even with good frame rates.
What are most performance-heavy components?

1 Answers
Chris_Simul Staff answered 3 years ago

Hi PrivateFox.
Good question. As you mention, Cubemap Resolution is the main contributor to performance, as it controls the size of the volumetric texture used.
The defaults we have set are generally a fairly low performance setting, set that way so people with lower end setups such as yourself. Amortization is on that has a slight bit of leeway, if you haven’t got any movement you can opt to increase this for slightly better performance, this goes across both regular amortization, atmospheric and the setting on the trueSKY light.

In 4.3 the window grid and window width settings within the “render” settings of the trueSKY actor may also increase performance. I halved them when doing some quick tests and it seemed to have quite a shift for performance, however might cause some slight artifacts as you will be altering the size of the actual grid system we use when drawing in clouds.

The noise textures used for edge noise as well as cell noise can also be reduced in size, there may be a slight quality drop, however it will come with a slight performance improvement too, especially if these have been increased from default.
I hope some of these help at least slightly, let me know how it goes and I can potentially dig a bit deeper for you.

PrivateFox replied 3 years ago

Hi Chris, and thanks for replying. I tried your tips and they can help to some extent. But I think that True Sky in Unity have some optimalisation issues or something.. I tried TrueSky in UnrealEngine, which I always thought was much more demanding on graphics. But here everything runs much much better. I don’t know exact FPS, the counter was running so fast that I didn’t see the value. But it was definitely over 60 frames. With the help of your performance improvement tips, fps has increased even more. In addition, SkySequencer was much more responsive than Unity (eg by moving the “Cloudiness” slider) so the results of changes were updated quickier in scene view.
And it also seems to me that UE4 has much nicer clouds at small Cubemap Resolution values. even with a resolution of “128” it was pretty good. compared to Unity where at this value the clouds pixelated unpleasantly.

Too bad Unity HDRP has such problems..

At least the good news is that my graphics card isn’t totally useless.