Author Topic: Cloud Tryouts  (Read 13980 times)

Offline FrankB

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Re: Cloud Tryouts
« Reply #45 on: September 24, 2008, 03:43:28 PM »
The thing is, Calico, that your render is excellent with shapes and all, but what you're actually looking for is the complete opposite of what TG2 is doing. Looking at your image, it occured to me that I'm looking at a negative of a real fly-by saturated cumulus. I fly fairly often on my travels, and of course that's a great opportunity to study clouds :-)

I took your render, and created a little mock-up to present my point (conceptually). If I cut out the cloud, invert the image and then up the exposure and gamma, paste it back into the original with the blue sky, I get the following:

12846-0

What we need TG2 to do is *darken* the cloud egdes, not to make them lighter than the rest.

Regards,
Frank

Offline rcallicotte

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Re: Cloud Tryouts
« Reply #46 on: September 24, 2008, 06:01:00 PM »
Frank!  Thanks for the insight!  You're right.  That is what I've been trying to figure out and I'm not sure I knew it until now.  Those edges define the "poof" in the cloud.

But, how?
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Offline Tangled-Universe

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Re: Cloud Tryouts
« Reply #47 on: September 24, 2008, 07:12:33 PM »
That's "fairly" easy Calico:

Make the cloud color and scattering color very dark, around 0.1 - 0.25 for both. Then increase the fake internal scattering and you might also have to play again with light propagation and mix again. It's difficult to predict which fake internal scattering strength, but it is probably around 1.
Remember to have low amounts of glow for better depth-effects.

If you would like to send your tgd I could give it a go for you. It seems I will have some time for TG2 soon after a long time...

Martin

Offline rcallicotte

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Re: Cloud Tryouts
« Reply #48 on: September 24, 2008, 07:35:19 PM »
Thanks TU.  This is a good idea.  I'll try it, but the lighting is so much more teeter-tottery than just changing the Fake Internal scattering to make it work like this that I think I'll keep at it.

Seems selfish of me, you know, but I've been playing with the lighting for the last two weeks or so and have it about where it want it, except for this. 

As soon as it's "road worthy", I'll post the image.



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Offline Tangled-Universe

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Re: Cloud Tryouts
« Reply #49 on: September 24, 2008, 07:42:29 PM »
Thanks TU.  This is a good idea.  I'll try it, but the lighting is so much more teeter-tottery than just changing the Fake Internal scattering to make it work like this that I think I'll keep at it.

Seems selfish of me, you know, but I've been playing with the lighting for the last two weeks or so and have it about where it want it, except for this. 

As soon as it's "road worthy", I'll post the image.





Well, you've seen my work on it, so I do know what's involved...

Basically, just doing the first steps I described inmediately gives the desired effects, yet not the result.
It's quite difficult to get the edges coloured just dark enough, but not too dark and the same for the lightness of the inner sides of the clouds.

Offline FrankB

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Re: Cloud Tryouts
« Reply #50 on: September 24, 2008, 08:36:03 PM »
Martin & Calico,

I'm fairly certain the cloud layer in TG2 cannot do that without severe (too many) compromises on other aspects of the cloud. I mean, I'm still open for sugestions, but I also have the impression I have already tried everything possible. I had a few semi-successes, but never to my satisfaction. I think (I hope) that Matt will find some time after the final to give the cloud layer another shot. On my wishlist besides a different (or at least additional) lighting and scattering strategy, would be a modified fractal flavour that gives an out-of-the-box cauliflower look, and another option, maybe an input, to influence the cloud profiles. I think it would also be necessary to take another shortcut on the way the atmosphere and the clouds are sampled, so that speed of rendering would increase.
But I'm drifting off topic. So as for the dark cloud edges, I don't think it can currently be done except with insane render detail settings - maybe.

Regards,
Frank

Offline rcallicotte

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Re: Cloud Tryouts
« Reply #51 on: September 25, 2008, 03:24:41 PM »
Thanks Frank.  Whew.  What a relief that it's not just me nor just my ineptness. 

I will spend some more time on this today.  And then I might just live with the results until later.  Of course, I'm open to clear instructions, but the insane render detail settings is where I've spent my last three weeks.



Martin & Calico,

I'm fairly certain the cloud layer in TG2 cannot do that without severe (too many) compromises on other aspects of the cloud. I mean, I'm still open for sugestions, but I also have the impression I have already tried everything possible. I had a few semi-successes, but never to my satisfaction. I think (I hope) that Matt will find some time after the final to give the cloud layer another shot. On my wishlist besides a different (or at least additional) lighting and scattering strategy, would be a modified fractal flavour that gives an out-of-the-box cauliflower look, and another option, maybe an input, to influence the cloud profiles. I think it would also be necessary to take another shortcut on the way the atmosphere and the clouds are sampled, so that speed of rendering would increase.
But I'm drifting off topic. So as for the dark cloud edges, I don't think it can currently be done except with insane render detail settings - maybe.

Regards,
Frank
So this is Disney World.  Can we live here?

 

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