Newbie lost in clouds - a few questions

[Tiles]

I am fairly new to Terragen 2. I have read a ton of postings here now, have googled for tutorials, have downloaded the examples in the cloud libary thread, but cannot find the right answers. My problem is that i cannot find the right places to tweak the shape and appearance of my clouds. How is all this stuff connected? What is the best way to make a cloud higher, bigger, more fluffy, control how the clouds are spread across the sky, and and and ... . I am lost. Could you be so kind and enlighten me a bit?

One of my main questions are:

Let's say i want to make my clouds here bigger. Which slider is it? One of the sliders in the Pattern panel? Or one of the sliders in the Layer panels? Which one? I have tweaked around the Feature scale slider in the Pattern panel for example, but the result was nearly not visible.

Where can i adjust the dispersion of my clouds without making them smaller? I tried so much now and always end in something not longer useful.

Let's say i want to get rid off of the grainy look in the lower part of the picture. Where does this even come from? Where can i control that grainyness?

Let's say i want to decrease the amount/strength of the god rays, where do i? Where can i make the atmosphere more clear? Haze density slider seems to do nothing ...

Let's say i want to make the sun smaller because it is simply too big at that sky. Where can i?

[rcallicotte]

I suggest going here - http://forums.planetside.co.uk/index.php?board=2.0  Go through the User's Guide and some of the tutorials.  I believe you'll find you will have a better all around understanding and it won't take long to get there.

To answer some of your questions -

Clouds take time to understand.  You'll need to find tutorials or go to the File Section to find some free examples of good clouds.  Play with these samples to better understand.

Graininess is controlled by the cloud's Quality tab.  Usually a 2 or higher in the Quality setting will help.  I tend to like 256 samples to 512 samples in the Cumulus, for example.

Atmosphere takes time.  Find some example TGDs or TGCs to see what people have done to better understand.  Number of samples in Atmosphere should be from 16 to 48, depending.

The sun is controlled in the Lighting section, Sunshine object, Angular Diameter.

[Tangled-Universe]

Graininess is controlled by the cloud's Quality tab.  Usually a 2 or higher in the Quality setting will help.  I tend to like 256 samples to 512 samples in the Cumulus, for example.

Atmosphere takes time.  Find some example TGDs or TGCs to see what people have done to better understand.  Number of samples in Atmosphere should be from 16 to 48, depending.

Sorry Calico but I really don't agree with these explanations:

A quality setting of 2 in the clouds tab will definitely give good results, but will render way too long.
It's better to start testing with crop renders at quality settings of 0.7 and then increase with .1 increments if necessary.
It's useful that you choose your crops carefully, it's best to crop a section which has a lit and unlit (shadowed area) part of the clouds.

As for cloudsamples: the number of samples depend on cloud density, edge sharpness and depth. Play with these to understand their relation.
Simply put; high density, high edge sharpness and high depth will result in a high amount of cloudsamples required for a good result.
So you can never say in advance that a certain cloudsample value is the right one.
When you play with these settings you'll see that when you keep the qualitysetting the same that the amount of cloudsamples required to get the same quality will increase when you increase the density, edge sharpness and/or depth.

This also accounts for the atmospheric samples.
In many cases 16 to 48 samples will give decent results.
But when rays and shadows in atmosphere (and shadows on terrain as well) are prominent you definitely have to increase the atmospheric samples.
The image Tiles posted here is a very good example for this. This image will still be very grainy with atmospheric samples set at 48.
Probably samples at 128 won't even give a clear clean crisp result.'

Logically, as for all quality settings in TG2 you'll have to find the right trade-off for each scene you'll make.
There's no real golden standard which will give the best result for each scene.

Hope this helps.

Martin

[rcallicotte]

Not agreeing with my explanations, when I'm saying 'usually' means it almost sounds like you didn't say 'there's not real golden standard', which is what I said in other words as well.  Giving the actual parameters is helpful.  From there, most people will likely experiment. 

But, your explanations are helpful and yet it takes more than our explanations for someone to understand these things, right?  It take playing around with some settings. 

Hopefully, Tiles will get a good start with this rather than believe one person understands it all over another.  No arguing.  Eh?

[Tangled-Universe]

No of course not

Starting at clouddetail levels of 2 doesn't really make sense and will in my opinion not improve Tiles' understanding of the process in chosing the right quality settings and how all the settings inter-relate. I just think, when giving values for a start, give more realistic starters and explain where to go from there and how stuff influences one and another. See what I mean?

[Tiles]

I suggest going here - http://forums.planetside.co.uk/index.php?board=2.0  Go through the User's Guide and some of the tutorials.

Thanks for the suggestion, but as told, i've already been there. There is nothing really useful when it comes to clouds yet. And as told, i have also already played with everything else i could find. But i am still confused. Now even more.

What i battle with is the fact that the stuff is so cluttered across a dozen tabs. And to find the important sliders is nearly impossible by playing around. Anyways. Thanks for the answers guys. Let's have a look if i can convert your hints and tips into at least a bit better clouds

[Tiles]

Yup, a bit better. Quality settings did a miracle here

Still a blind touching in the fog though. I have again touched this much sliders that i cannot longer say what did what

[Oshyan]

The basic shape of the clouds is controlled by whatever is connected to the "Density Shader" input, by default a "density fractal". You access the settings for this default shader with the Pattern button. There you can adjust Feature Scale to change the basic size of the cloud shapes and use Lead-in Scale to adjust the "macro-shapes", or the largest elements in the cloud shapes. Usually a combination of both will give the most visible effect. As with most settings in TG2, these are measured in meters, so you will need fairly significant changes to see large results.

To get "dispersion" of clouds, as you call it, adjusting the Lead-in Scale will probably help. Try fairly large values. You might also try messing with Density Shift (in the Density Shader, not in the Cloud Shader) or Bouyancy (on the Tweak Noise tab). It may take a combination of settings to get exactly what you want.

There are two main elements that contribute to grain in an image - clouds and atmosphere. These are controlled as far as quality goes by the number of samples, and this is set separately for each cloud layer, and for the atmosphere. In cases where you see noise that is not directly *on* a cloud area, it is most likely the atmosphere. So in the first image example you would increase atmosphere samples, as it appears you have done in the 2nd image. I'd say 64 samples should do ok. You could also increase cloud samples as the clouds themselves are a bit noisy, but the atmosphere is what is giving you most of the noise here. Note that the clouds include a convenient quality slider which, when set to 1, usually provides a good balance of quality and render time. Of course you can always go beyond 1 if needed.

The Haze Density should absolutely have an effect, I'm not sure why it isn't. I believe if you adjust Haze Glow Amount it might have an effect on the rays, but there is no specific "godrays" setting, they are just a natural part of the rendering process. Because they are produced as a realistic result of rendering and not a "special effect", they are less explicitly controllable.

To make the sun "smaller", adjust the "haze glow amount".

I hope that helps you get a start at understanding these settings and how they interrelate. The best thing to do is simply experiment and watch the effect. Some baseline knowledge about how TG2 works is helpful however, and that's what you can find in the existing documentation here in the forums, although it's not yet complete.

- Oshyan

[Tiles]

That's what i was looking for. Definitely helps alot. Many thanks