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General => Terragen Discussion => Topic started by: Sethren on December 23, 2006, 10:32:33 PM

Title: Faking planetary-scale weather systems
Post by: Sethren on December 23, 2006, 10:32:33 PM
A long while back i had discussed this concept with matt about seeing planetary scale weather systems from orbit and was wondering if it can be done with the current version of TG2. I was thinking in the density fractal feature scale just making the scale very large and adding some warping effects to the overall pattern of the clouds to make it look as if they are apart of a massive moving weather front or perhaps a jet stream of sorts. A lot to think over but any other input on this would be greatful. 
Title: Re: Faking planetary-scale weather systems
Post by: Oshyan on December 23, 2006, 10:52:42 PM
This is definitely possible now. It's just a matter of using the right density shader. Some decent results have been achieved using just a single default density shader and adjusting the warping settings in it. You could create a nice, complex network of shaders above that to get better results.

I think creating a good, realistic-looking global cloud model would take some time and involve multiple cloud layers, which you'd have to blend smoothly and realistically together, but I do think it's possible currently. It would just take a lot of work. If you don't need to see your clouds from space *and* from the ground, then focus on the large-scale stuff. Usually only 1 or 2 layers would be necessary for that.

- Oshyan
Title: Re: Faking planetary-scale weather systems
Post by: Sethren on December 23, 2006, 10:56:02 PM
Hmmm... at the moment i can try it at ground level and as terragen becomes more optimized i could try the space based renders. I figure a dozen or so cloud layers at least for the space stuff later on but just a hunch at this point. Something to think on for sure.
Title: Re: Faking planetary-scale weather systems
Post by: Oshyan on December 23, 2006, 11:05:00 PM
Actually space renders are generally much faster than ground renders. :D

You will have different needs from space than from the ground. Making the two mesh is the hardest part, I think. In other words making a cloud system that you can view from space and that looks realistic from there, but then you can also zoom down to planet level and the realism remains. I've done one or the other but not both.

Still, I think it's currently possible...

- Oshyan
Title: Re: Faking planetary-scale weather systems
Post by: Sethren on December 24, 2006, 12:14:34 AM
What might be some good cloud size settings from space just for a quick run through so i can get a basic idea of what to do. I figured once i have the overall size down then i can take everything else from that point on.
Title: Re: Faking planetary-scale weather systems
Post by: Oshyan on December 24, 2006, 12:25:09 AM
Well, I'd start with a Lead-in scale of between 1e+006 and 5e+006, a Feature Scale of 100,000-500,000, and a Smallest Scale between 500 and 1000. Really big. :D That should give you a very basic starting point.

- Oshyan
Title: Re: Faking planetary-scale weather systems
Post by: Sethren on December 24, 2006, 12:51:06 AM
Alrighty!     :D
Title: Re: Faking planetary-scale weather systems
Post by: 3DGuy on December 24, 2006, 09:28:06 AM
I've been playing with it and ended up with this:
(http://temp.theglasseye.nl/planetweather.jpg)

If you like to explore my settings, I've attached the tgd file.

The extreme white patches are snow I think from the planet surface shader.
Title: Re: Faking planetary-scale weather systems
Post by: Sethren on December 24, 2006, 06:08:13 PM
Yup, those white patches are snow.

Thank you for the file attachment, i have not spent to much time exploring large clouds yet as i had spent 3 1/2 hours last night rendering a scene i am actually satisfied with.
Title: Re: Faking planetary-scale weather systems
Post by: Sethren on December 26, 2006, 08:43:53 PM
http://www.ashundar.com/CPG/displayimage.php?pos=-3581

My first acceptable Terragen 2 planet. A very wet ocean planet with scattered continents and a lot of cloud cover due to the great amount of air moisture from the overwhelming ocean cover. This is still a WIP as i need to have large open spots in the cloud patterns and figure out how to use the planet shader to get more green and less grey.

Thanks to 3DGuy for the file and JavaJones for the suggestions.    ;D
Title: Re: Faking planetary-scale weather systems
Post by: king_tiger_666 on January 28, 2007, 06:05:15 PM
partly based on 3dguys file, but with the addition of a image map hurricane file and different cloud settings etc... looks ok for my first of this kind...

i forgot to add the the planet shader was default settings since i was really only trying to get clouds looking decent
(http://homepages.slingshot.co.nz/~rawjdmbj/planet.jpg)