How to cover the sky with clouds?

Started by CG MANIA, March 18, 2018, 05:05:02 PM

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CG MANIA

Hi,
I need to have the camera above the clouds, so dense you find it difficult to see the ground, and you just see the clouds until the horizon.
I've tried Global dense but it doesn't even show as a cloud.
Which one should I choose and how do I make it till horizon?

A bit like this (just the clouds density and extension to the horizon):
https://www.artstation.com/artwork/NPm6d

archonforest

Dell T5500 with Dual Hexa Xeon CPU 3Ghz, 32Gb ram, GTX 1080
Amiga 1200 8Mb ram, 8Gb ssd

WAS

#2
Global clouds have super large scale, to be seen from a high altitude or from orbit. You can easily crank the cloud fractal scale down to 500m and you'll have denser clouds at your local. You can play with the seed coverage adjust and see what you get. The Edge Sharpness of the global cloud is also important to create those cloud edges you're used to without being too thin/hazy. They also have warping set, which is a bit excessive for this approach and should be toned down or disabled.

CG MANIA

Stuck in the first sentence, I cannot find a parameter called "cloud fractal scale", I'm new to Terragen, but years in Vue.
The attached picture is my 20 minutes of work in Vue,
[attachimg=1]

but it is very frustrating to even find the right parameters to adjust in Terragen.
Vue is not calling the parameters correctly anyway, but I got used to it. Now another Sherlock Holmes investigation in Terragen to find what covers the sky. It pretty much is the simplest and most basic thing to start with: how covered is your sky? I really appreciate the guidance but there is nothing called "cloud fractal scale". It would help to call it a way I can find it, how it is called in the parameters.

I need to start by defining how overcast the sky is. How do I put more clouds in the sky? in exact parameter names?

WAS

Inside your "Density Fractal", there is a slider called "Feature Scale".  The Density Fractal is the shape of your clouds.

luvsmuzik

If your camera in Terragen is already set above your cloud layer(s) and you have holes that show terrain below, increase coverage in small increments. There is a preview in the Density fractal (little blue box> upper right) that may help you as well.

Up to you, but if you are just going for one image, instead of global layer, adjust the radius of a regular cloud layer. That may or may not cut render time, in my opinion.

CG MANIA

#6
Cloud Altitude 1000
Cloud Depth 1500
Edge Sharpness 100
Coverage Adjust 2
Feature scale 500
Lead-in Scale 100
Smallest scale 2

But I can't get them to move up, they keep their heads down next to each other, I need variety in height between them
[attachimg=1]

I'm working with the Global Dense, should I use another maybe?

luvsmuzik

#7
Or add another layer, smaller radius, more height, less coverage layer a few meters above global altitude.

Discussion on vertical displacement very recently

https://planetside.co.uk/forums/index.php/topic,24194.msg244930.html#msg244930

You may or may not understand this,, I am still experimenting with cumulus clouds myself, I have not tried with full coverage.

WAS

#8
You might want to try playing with warping the density fractal, and playing with the altitude offset function. For example, this is just a basic PF warper with extreme displacement, and than the same PF duplicated with 500 meters of displacement at a scale of 250 (probably should be bigger) converted to a vector, and than Y scalar. The warping is probably a bit to strong, and I clearly forgot to turn of the Octive Perlin Warp from a previous test. Woops.

I'll see If I can make it more natural and throw up a TGC.

ajcgi

I often play with the depth modulator too. That helps with variety.

[attachimg=1]

luvsmuzik

Quote from: ajcgi on March 20, 2018, 11:31:31 AM
I often play with the depth modulator too. That helps with variety.

[attachimg=1]

Aha! Now why didn't I think of that...Soooo many node hookups!

WAS

Quote from: ajcgi on March 20, 2018, 11:31:31 AM
I often play with the depth modulator too. That helps with variety.

[attachimg=1]

Would this not breakup the clouds more then retaining the blanket? I use this to create like prairie clouds, small puffs rolling across the sky. Haven't played with it much though.

PS I have added a TGD file to the link I provided above with a new example.

Oshyan

It's interesting that this created an entire discussion. To me, using Terragen for years, it is fairly intuitive. You create a cloud layer, adjust a few settings, and you get a result very similar to what is desired here.

It sounds like what is desired that is *different* from the default cloud layer is more coverage (and a camera position above the clouds). I would first start by putting the camera where I want it to be because only then can I adjust cloud parameters and see if it is giving me the result I want (you cannot adjust cloud settings from the ground and be confident it is doing what you want *above* the clouds). So I move the camera up, camera movement is fairly clear too, right? Now I'm above the clouds...

OK so now so let's see about coverage... Well, there is a Coverage slider in the cloud layer, so I just increase that until there are no more gaps in the clouds but more like a continuous "carpet" of clouds. Using a value of 2 actually worked fine, but lower values may work well also. A value of 0.8 or so was patchier but matched some of the other attempts people have posted here. This is the image I get from Coverage of 2.0 with Easy Cloud Large Cumulus (I adjusted sun position to match the Vue reference):
[attachimg=1]

Basically I arrived at this result by thinking about what kind of cloud types and sizes I wanted - to match the reference I thought a Cumulus would be good - and then creating that type of layer, moving my camera to a good position, adjusting sun, and then changing cloud settings in the Ray Traced Preview mode until I had what I wanted. Pretty straightforward. Of course the clouds fade out in the distance, but this is just because the layer is Localized (it is hoped this is clear from the Radius value, but I can understand that the "Localize" checkbox being grayed out may make that part unclear).

So certainly one issue with what CG Mania tried is using Global Clouds. Perhaps it is not clear enough in the cloud preset list, but they are intended for *global* views (i.e. from orbit). Maybe those presets should be at the bottom of the list because they should be used much less often and are less realistic (they are good for orbital views, but not for anything near the ground).

It's also a good idea to pay attention to the range of values in the sliders, even if you want to enter values manually. In this case the Coverage maximum (for Easy Clouds) is 1.6. That means we are suggesting that the *maximum* value you'd want to use is 1.6. You can always use higher (or lower) values than the minimum and maximum in the slider, but in most cases the slider suggests a "normal" range of appropriate values. I would guess that a value lower than 2.0 would work fine for Coverage here, for example.

Now I know of course that I am very familiar with how TG works, so I know how to do this. I'm not trying to make anyone feel stupid here, I hope I haven't, I imagine all of you would have taken a simpler approach if you knew what to do. So the failure here is that the simple route was for some reason not intuitive. Thus what I want to know is which of these steps was *not* intuitive to the original poster (CG Mania) and many of the rest of folks here (who did achieve nice results but took more complicated approaches, needlessly complicated in my view). We want to make workflow better so it's vital to understand where people get lost!

- Oshyan

WAS

#13
Quote from: Oshyan on March 20, 2018, 05:18:34 PM
It's interesting that this created an entire discussion. To me, using Terragen for years, it is fairly intuitive. You create a cloud layer, adjust a few settings, and you get a result very similar to what is desired here.

It sounds like what is desired that is *different* from the default cloud layer is more coverage (and a camera position above the clouds). I would first start by putting the camera where I want it to be because only then can I adjust cloud parameters and see if it is giving me the result I want (you cannot adjust cloud settings from the ground and be confident it is doing what you want *above* the clouds). So I move the camera up, camera movement is fairly clear too, right? Now I'm above the clouds...

OK so now so let's see about coverage... Well, there is a Coverage slider in the cloud layer, so I just increase that until there are no more gaps in the clouds but more like a continuous "carpet" of clouds. Using a value of 2 actually worked fine, but lower values may work well also. A value of 0.8 or so was patchier but matched some of the other attempts people have posted here. This is the image I get from Coverage of 2.0 with Easy Cloud Large Cumulus (I adjusted sun position to match the Vue reference):
[attachimg=1]

Basically I arrived at this result by thinking about what kind of cloud types and sizes I wanted - to match the reference I thought a Cumulus would be good - and then creating that type of layer, moving my camera to a good position, adjusting sun, and then changing cloud settings in the Ray Traced Preview mode until I had what I wanted. Pretty straightforward. Of course the clouds fade out in the distance, but this is just because the layer is Localized (it is hoped this is clear from the Radius value, but I can understand that the "Localize" checkbox being grayed out may make that part unclear).

So certainly one issue with what CG Mania tried is using Global Clouds. Perhaps it is not clear enough in the cloud preset list, but they are intended for *global* views (i.e. from orbit). Maybe those presets should be at the bottom of the list because they should be used much less often and are less realistic (they are good for orbital views, but not for anything near the ground).

It's also a good idea to pay attention to the range of values in the sliders, even if you want to enter values manually. In this case the Coverage maximum (for Easy Clouds) is 1.6. That means we are suggesting that the *maximum* value you'd want to use is 1.6. You can always use higher (or lower) values than the minimum and maximum in the slider, but in most cases the slider suggests a "normal" range of appropriate values. I would guess that a value lower than 2.0 would work fine for Coverage here, for example.

Now I know of course that I am very familiar with how TG works, so I know how to do this. I'm not trying to make anyone feel stupid here, I hope I haven't, I imagine all of you would have taken a simpler approach if you knew what to do. So the failure here is that the simple route was for some reason not intuitive. Thus what I want to know is which of these steps was *not* intuitive to the original poster (CG Mania) and many of the rest of folks here (who did achieve nice results but took more complicated approaches, needlessly complicated in my view). We want to make workflow better so it's vital to understand where people get lost!

- Oshyan

I think the biggest difference here is simply using Easy Clouds over a cloud density fractal. Clearly, the look with Cloud Layer v3 by default is flat and hazy on top as shown in images or by adding one and upping density yourself (default edge sharpness). The next issue is how the cloud depth works which creates only small peaks. Third issue is raising the cloud depth so when you raise actual peaks, they don't flatten against the boundaries.

Easy Clouds, lacking configuration, I shy away from in general. By it's name alone I assume it's a drop and go feature for non-focal points.

Oshyan

#14
QuoteI think the biggest difference here is simply using Easy Clouds over a cloud density fractal. Clearly, the look with Cloud Layer v3 by default is flat and hazy on top as shown in images or by adding one and upping density yourself (default edge sharpness). The next issue is how the cloud depth works which creates only small peaks. Third issue is raising the cloud depth so when you raise actual peaks, they don't flatten against the boundaries.

Some of the issues you mention are only true of the Global cloud layer, for example the "hazy" look, etc. A default "Generic" cloud v3 looks like this (below), once you increase the depth range to 6000 to match the "Large" Easy Cloud.
[attachimg=1]
Increasing the depth should derive obviously from considering the look one wants (bigger/taller clouds), and one couldn't expect it to equal the look of Easy Cloud or any of the other deeper cloud setups you and others posted without increasing depth. Hopefully that is also intuitive, but I guess maybe many people don't actually know the real-world height of cloud formations...

You can then increase Coverage Adjust to 1 to get this:
[attachimg=2]
However yes, if you want more "dynamics" in the elevation range of clouds, then you need to do more work, similar to what you did. Increasing Coverage to 2 flattens things out a lot as the cloud starts to totally fill the vertical cloud volume, since it has no input varying the height separate from cloud coverage:
[attachimg=3]

What's important to realize, though, is that Easy Cloud includes a lot of behind-the-scenes stuff to help make the shapes more dynamic, and avoid the flattening out with increased coverage. The image and scene I posted before demonstrate this: with a Coverage of 2 dynamics are still maintained. The whole point of Easy Cloud is to try to make things more intuitive and quicker to achieve normal, realistic results without a lot of tweaking or in-depth node network setups.

Now for you, being presumably more familiar with Terragen, the node network, etc. then yes absolutely you can avoid use of Easy Clouds if you prefer. For someone like CG Mania who is clearly just starting out and trying to learn things, I think Easy Clouds are absolutely appropriate.

But actually I would caution *any* user against simply taking the more complex route to something without first trying the simpler approach. You may save time and effort by using built-in presets and settings rather than creating things from components like Function Nodes, and as we work to make Terragen easier to use, this will be increasingly so. The introduction of Easy Cloud is part of that effort, and would ideally not be ignored by even power users. It's intended to help everyone achieve specific, realistic results, no matter skill level.

The key is in knowing what it's good and useful for and using it in those cases, and not in situations where it's not as powerful or configurable as needed. True mastery lies not in avoiding all "easy"/simple/less-configurable aspects of the software, but instead taking the most effective route to the desired goal, which may well include some easy/preset options, along with more custom work to get specific "hero" cloud formations, etc.

- Oshyan