Cloud Quality Settings Question

Started by BooKara, April 03, 2017, 01:58:55 PM

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BooKara

I have run into an extremely strange scenario regarding quality settings on clouds and want to know if anyone else has seen this and has a work around.
Simple put the quality settings keep changing on me.

I recently did a low quality 40 frame render of clouds animating that took a few hours. I liked the look and decided to do a better quality overnight render.
Much to my surprise I had frames that rendered very noisy and others that did not. The problem was the quality settings (Set to 1) kept changing.
I decided to set a key frame at 1 with the Mode set to Linear. Still changed. Here is where it gets really good…..When I save, close and open the project again, I have seen the settings change from extremely low negative numbers to up over +400. Here is the best part….(see images)…without changing ANYTHING and with the cloud still set to 1, I get (Image 1). You can see noise right? THEN…I will simply “Wiggle” the quality slider "just a little" but keep it at 1, render again and I get a better result (Image 2)

I’m sure it’s me since I’m new to Terragen but can someone point me to the fix?

N-drju

Hm, cloud detail indeed seems to behave oddly. It changes on me as well, but not with such great values. ;)

Have you tried using the animation tab in the cloud fractal settings? I never tried it but from the look of it, it just might be what you look for. See, it has frame references and noise settings:

[attachimg=1]
"This year - a factory of semiconductors. Next year - a factory of whole conductors!"

BooKara

At this point it won't hurt to try anything. Thanks

cyphyr

If you're happy with the look of your cloud settings now I'd leave the 4D noise alone. Good though it is it will look completely different from your original setup.
Couple of questions ... What version of Terragen are you using and what cloud node are you using (V2, V3 or Easy cloud)?
Some more questions ... Are the clouds animated in some way, is the camera animated?
Did you render a GI_Cache first?
Can you post the tgd file or just a clip of the clouds?
If we can replicate the issue then we're a step closer to finding a solution.
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BooKara

Yes I am happy with the current look of the clouds and enabling 4D noise does indeed change that. I was going to mess around with it anyway but doesn't look like it will help.
As for your question:
           I'm using TG4 Build 4.0.04 64 bit and 8 processor cores
           The cloud is V3 with the cloud quality set to "1"
           The clouds are animated but that doesn't explain why sometimes it works and sometimes not using the same machine and settings.
           The camera is not animated and set to "Spherical"
           Lastly, I won't be able to post the TGD or clips. I would have to run it up the line and would take too long for approval. ;)

Hope this helps.

cyphyr

Hmm odd indeed. I've tried a variety of options to try to get the quality slider to behave as yours does with no luck.
Sometimes the old tricks stiill work ...
Select everything in the atmosphere group (I'm presuming that is where you have your cloud setup) and copy and paste them into a new instance of Terragen.
See if the problem persists. If it's gone away copy and paste the atmo node and then the lighting nodes and lastly everything else you need for the scene.
Basically re-build the scene in a new terragen file.
I've done this a couple of times before to get out of problems that had no other obvious solution.
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BooKara

That's a great suggestion. I'll try that and post the results.

Oshyan

There are times when values may change in very minor ways, usually due (I think) to rounding. But I've never seen anything with such a large change like you're showing. Does your TGD file reliably reproduce it?

- Oshyan

BooKara

My TGD file will reproduce minor changes 9 out of 10 times. I have noticed the larger changes prior to me adding a key frame at the start and end of my animation locking it "1" on Linear path. Interesting as well, though I have added a key frame at "1" even that changes after moving to another frame and then back, if ever so slight, without re-launching. (see images)

Matt

Which parameter(s) were you animating in the cloud? Animating some parameters might be confusing the automatic relationship between quality and internal sampling settings. If I know exactly which parameters you were animating I'll try to reproduce the problem.

Matt
Just because milk is white doesn't mean that clouds are made of milk.

BooKara

Matt,

In my animation I'm creating a looping Cumulus cloud that fades over time and a copied version of itself that transitions in so that the end matches exactly with the beginning. To do this I have animated several parameters but mostly I animate the "Coverage adjust" so that the cloud, at start, looks like it's fading away as the other one comes in.

For the most part this has worked, though the scene gets darker as both clouds are merging ontop of one another, which is to be expected.

Here is something I noticed just today though. When I copied a cloud node, with/without animation applied, the quality changed 9/10 times. (See images)
I did not change any parameters and things changed. This first image quality was set to "0.300192 (for quick rendering) and when I copied the node the quality changed to "0.0186866". I thought this maybe due to the low quality setting I started with but when I started with Quality "1" the setting still changed when I copied the node.

Hope this helps a little.