This is intended to be a discussion of the future possibilities of clouds and their appearance.
If you are like me, you miss the original cloud/sky appearance and are struggling to come to terms with the ‘clouds made of millions of little puffs’ approach that Asobo seem to be taking. At first the puffs were much too big and too disorganized but occasionally made some decent looking fair weather cumulus.
Today I took a flight from C16 frasca Field to Indy Exec KTYQ and then on down to Indy Intl (KIND). Theres some great PG just south of TYQ but thats another issue. As I landed at Indy I was noticing the cumulus off to my right and how the shading seemed to be smoother and closer to realistic. I’ve also been noticing that the apparent resolution of lower altitude cumulus seems to be increasing (the puffs keep getting smaller) and the layouts of the puffs are taking more and more realistic patterns (in my opinion).
So I’m sitting there just looking at the clouds and it hit me that not only can you make any shape cloud using small enough puffs but you can change properties of individual puffs to create a very wide variety of clouds. If the high altitude overcast weak anemic pathetic blurry bowties can in fact be blurry then so can any or all cloud puffs that make up any given cloud. In addition, you don’t need to run a bunch of mathematical shading models on each cloud based upon its density because you can assign a light attenuation factor to each puff that varies with its density/blurriness. The more puffs you need to make a cloud, the more shading will automatically occur and I think it would also be easier to control the colors of the clouds in that manner.
It feels like they are setting up for ray tracing (and you should know that I know next to nothing about ray tracing or even how this sim does what it does or will do what it will do).
This thread is just the thoughts I had today and how they gave me hope for a brighter future of improving cloud/sky appearance.
so - thats it…any thoughts?
3 Likes
Caveat: I’m neither an expert in weather nor in graphics. But I have some thoughts. (Though I do have more than a private pilot’s understanding of weather.)
Caveat #2: Not an employee. I have no more contact with the development team than any regular user. My opinions are my own.
I’m not sure if the development team would call them “puffs.” I don’t spend enough time in the gaming space to know what the right word might be, but I’m sure someone around here might have an opinion as to what the right word is.
I don’t think it is possible to create true cirrus clouds in the sim right now. Unlike cumuloform clouds*, cirrus clouds are made of ice crystals. (* Note: Cumulus clouds can also have ice crystals on them. But they are primarily liquid water.) I’m not 100% sure of this, but I think that their iciness is the reason that real cirrus clouds appear brighter in the sky than cumuliform clouds.
With the “puff system”, I think that the sim can render cirrocumulus clouds but not cirrus clouds.
2 Likes
What I’m picturing – each puff can vary in both transparency and blurriness. Right now most if not all of the puffs are pretty much the same - only their layout changes. But what if puffs were blurred and made more transparent in some areas and less in others and laid out in lacy patterns where it wasn’t noticeable that the cloud was actually lots of little puffs? I think it would work for any cloud. Maybe not..I dont know but Id like to hope so.
If you can’t make cirrus with puffs – I really have to wonder how thick cirrus clouds are. They can’t be very thick. Maybe trying to do cirrus clouds ‘volumetrically’ is a waste of time? Maybe we should use 2D images for cirrus and rely on a ‘volumizer’ for when a person gets near them. Id be plenty happy with that myself.
The thing with 2d images is that it looks same every single time. They need to create randomly generated textures then with some type of algorithm that makes that randomly generated noise to look like cirrus clouds. Well, if cirrus clouds are not possible with volumetric clouds right now i bet it will happen in the future.
I know Seb mentioned in a q&a some time ago and i agree with him. He said in real life a cloud type is formed because of the weather condition.
The issue with adding specific types of clouds into the sim is that those will appear where those are not supposed to be. They start to appear all over the world all the time where the condition isn’t met to form those types of clouds in the real world.
That happened here in Sweden after su7 were released. I got Volcanic ash TC type of clouds all the time when before su7 i got the clouds that were fitting the conditions here at that time of the year. Then “popcorn” clouds started to appear all over the world.
2 Likes
Makes sense. Try to make paragraphs in your post, it was hard to read. THX 
thanx for letting me know 
Will think about that next time 
2 Likes
My apologies! Grammer police here… LOL!
Mod edit: corrected so the thought is preserved, but used more compliant language. Please carry on. Thanks.
Some of the clouds we call cirrus are jet trails but the cirrus I’m interested in are from when a distant line of storms has their tops blown off and ‘downstream’ a few hundred miles (or more). I know Jorg was talking about getting sources for both upper level winds and turbulence and so maybe they could use those to decide where to place cirrus looking clouds. just let the particles follow the wind until they dissipate to the point of not being seen.
What do you think of the ‘puff approach’? Do you think it could make cirrus as well as most other types?
First of all I would start on educating me on “signed distance fields / singned distance functionas” and “ray marching”, since this is how dynamic voluminatric clouds with varying density are created in CGI.
Since all clouds are 3D shapes with varying density, each cloud typ can potentially created with this rendering method.
You’re talking about the cirrus anvil cap of a cumulonimbus incus. And when you get a cluster or line of storms, they can turn into a mesoscale convective complex (MCC) in which they pretty much share the same cap structure. They’re similar to, but a little different than a more typical fair-weather cirrus and contrails in that they’re a product of all that convective energy hitting the tropopause and spreading out (mostly downwind) instead of continuing upward. They’re also the last part of a thunderstorm to dissipate (cB typically dissipate from the bottom up).
But cloud genesis is pretty complex. It will have to be somewhat deterministic because there just isn’t enough computing power and granular input data such as soundings (skew-t/log-p) to synthesize realistic clouds from pure modeling, yet. That said, the FAA, at least, will usually predict where Cirrus are in forecast products and those could help to define the boxes in which they’ll be generated.
1 Like
I think MSFS really needs a cloud upgrade, For now does not matter what the weather is all clouds looks same. In reality every cloud is different from mighty Cumulonimbus to high level cirrus cloud. I know it is hard to recreate the exact atmosphere however textures can be upgraded. Back in the P3D and FSX days we had Active sky and Rex who used to provide textures for these clouds.
6 Likes
Well, i’m not an expert in rendering volumetric clouds. But i can make cirrus clouds look more like cirrus in custom weather by increasing the density on really thin layers of clouds.
Like this:
The issue i see the most is that most of the time in live-weather we can see the blue sky through the clouds. I would also like to see clouds that looks more stretched out as cirrus clouds. Or a wispy look if you know what i mean 
´
I know i showed weather from custom weather but in the end i think it’s the data they are using to show the clouds in live-weather that is the issue. I think the clouds will never look better than the data they are using to render the clouds with.
Using those puffs i bet they can’t make it look like cirrus. Those puffs i’m not sure what type of clouds they are trying to show. For example comulus clouds should most of the time block the blue sky because the density is always higher in those clouds near ground but in the sim they has really low density. I know when i increase the density of those comulus type of clouds i get volcanic ash instead. And that i think is a limitation of the rendering. I know Seb said they needed to change the rendering engine to be able to achieve higher density because improving that in current rendering engine it would decrease performance. Maybe same thing with higher clouds with high density?
2 Likes
While great for smaller convective clouds, it has its limitations. Mare’s tail cirrus like this…
…just can’t be well represented with a bumpy puffball (spheroid with 3D Perlin like noise function if I attempt to a more technical guess). You get translucent pancakes when you try. This cloud type has a fundamentally different shape, texture, optics from it’s icy composition, and even movement and growth behavior.
FSX represented them quite well with 2D textures. Asobo stated they didn’t want to use this method for their next gen sim. But I think procedurally generated 2D cirrus could be great. They could maybe extrude them a little vertically so they’re not infinitely thin and disappear momentarily as you fly through them.
It all comes down to developer hours though. And they’ve spent thousands and thousands on the clouds we’ve already got. It’ll be tough to convince them that they should spend that much more effort again when so many other areas demand attention.
4 Likes
I am curious to know whoch approach took Floyd’s epic clouds addon.
They have a cirrus type, and the cloud types rendered look great but I assume they are 2d textures?
Other sims like xplane took their own approach too. I think this type of things should be more or less transversal to all flight sims in order to recreate a nice and correct weather but I understand this is a daunting project to take.
I don’t expect too much change in the short term.
there are actually many engines that do variety of clouds fully volumetric very well.
Asobo just needs to find a way to do the same for their own engine.
4 Likes
I wasn’t aware anyone had good cirrus for the new sim. Do you have any pics to show?
Isn’t a hallmark of volumetric clouds the fact that they are constantly morphing?
The high clouds in the sim have never had the same morphing movement that lower cumulus clouds have – as far as I can tell anyway. Also, I encountered this:
and its clear the sim was trying to outline or trace some pattern. Hazard any guess as to what might be the source of such a thing? Maybe the idea of using satellite photos for cloud placement is alive and well?
I don’t remember if it was in reference to clouds specifically, or weather more generally, but Jorg did say in a fairly recent dev update that changes were coming that would ‘blow you away’, and I think one of the mods here said they would follow up on that.
Would really like some news about that…
4 Likes
I wish I could put this on a billboard that Jorg sees everyday on his way to work.
3 Likes
I don’t remember that. The transcripts are on the forum, if you can remember something of what he said perhaps you can find the quote?
