Nehg' In-Ska'

Started by dandelO, September 19, 2008, 11:17:21 am

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September 19, 2008, 11:17:21 am Last Edit: September 20, 2008, 10:42:26 am by dandelO
Right, first things first, Calico: Before you wet yourself, I'll post you the .tgd if you can accurately guesstimate the render time of this, to the nearest hour. ;)  :D :D :D

'Nehg' In-Ska' - Or, negative internal scattering  :D
I couldn't get negative values of FIS to work the way I'd hoped they would so, to make it work I needed a darker scattering colour than the cloud colour and then to apply positive FIS values. Look at the lovely little negative rays.

3 cloud layers, this is all, nothing more to report. Any questions, just ask. :)

Cheers for looking!



Wow, that's really great!  I reminds me of one of the images that an alpha tester made a while ago.  Let's see... how about a 23 hour render time? - A great Terragen resource with models, contests, galleries, and forums.



First things first: beautiful image! :)
I like the upper part best, where it get's brighter, for me it's a bit too yellowish, but never mind ;)

Difficult to predict the time, number of atmospheric samples / cloud quality / raytraced shadows / GI detail etc. etc. etc. And most importantly: do you have the new Cray CX1? With this one I would speculate around 3 hours with things cranked up to MAXXX. 8)

Keep us up to date with your little quiz, I like to find out the answer ;D
What you wish to kindle in others must burn within yourself. - Augustine


Very nice.  I love seeing clouds that look like this.  Very well done.  My guess is 32 hrs.


September 19, 2008, 07:44:16 pm #5 Last Edit: September 19, 2008, 07:47:56 pm by Matt
"Fake internal scattering" works with the basic cloud colour more than anything else, but it only varies the brightness according to how dense the cloud is at each point (it's a bit more complicated than that, but...). That's why sometimes it is better to use negative values, sometime positive. The "scattering colour" only affects global illumination that is calculated within the cloud, which is better at simulating scattering over large distances. So really they do completely different things.

I know we need to improve the documentation in this area :) But there are still a lot of changes I want to make to how scattering works in TG clouds.

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


QuoteThe "scattering colour" only affects global illumination that is calculated within the cloud, which is better at simulating scattering over large distances. So really they do completely different things.

Thanks, Matt. I had assumed that the FIS slider/values for brightness controlled how much luminance was being channelled to the 'scattering colour' in the main tab. It was on this idea that I made some attempts at volumetric fire, thinking that the insane levels of FIS needed for the fire were boosting the scattering colour, it certainly worked to my meagre means anyway. :)


Gimme-now-gimme-now, I have 23 hours, any advance on 23 hours, gennellmen? ...
You, sir! 32 hours! I have 32 hours...
Going once...
Going twice...
Gon... Uh?
48 HOURS! (gasps from the crowd!)
A fine piece for only 48 Hours, gennellmen...
Any advance on 48 hours? Do I hear 50, sir?... no? Who'll give me 49 hours for this fine piece? ...
No late bidders? No phonecalls from the foyer, from a certain Mr. Smith? ... 
Selling then at 48 hours...


If it's any help, my PC spec's are: Windows XP, 1Gb memory, 2x Pentium 2.8ghz processors... Piss poor in other words!  :D :D :D

Cheers all!


Awesome image!  I'm going with 18 hours.
-MATRIX2003-      ·DHV·  ....·´¯`*


There was a silent bidder overnight, gennellmen, who took the Nehg' In-Ska' lot for 2 hours.

The correct answer was: 2 hours to the nearest hour(1h 45m render time.)

I knew people would assume that the render times for such a scene must be sky high. ;) You can really coax TG2(albeit my limited free version) to perform things much quicker than some of the preposterous render times I've seen reported.

There are only 36 atmosphere samples.
The top cirrus layer is 2D - Number of samples = 9 - no acceleration.
The mid cirrus layer is 3D - Number of samples = 31 - conservative acceleration.
The low cumulus layer is 3D - Number of samples = 58 - no acceleration.

Enviro-light settings are defaults with Final GI detail = 1/1 supersampled

0.75 render detail/AA = 3.

The 'sun glow amount/glow power' sliders are the ones doing all the work here. The two 3D layers use a ridiculous amount of glow, well beyond the slider limits of '4'. These ones go to 25 with only slightly different 'glow power' levels than the defaults of 0.75.
Nothing is changed in my atmosphere parameters and I've purposely put the sample rate low. I think it could probably stretch to 24-28 samples without much decrease in quality.
And, the Sun is 2° below the horizon with a strength of 15.

I see some examples of clouds/atmospheres and such out there with shocking sample levels I'd never dream of using, you're all braver than me with TG! :D
This obviously isn't up to any standards of production quality or anything but, for an afternoons fiddling and a couple of hours(not even ;)) to render that fiddling, it's really great to hear guesses of between 18 and 48 hours!  :D :D :D

And I haven't even started with clouds in TG yet, I never had the means, an ill pc has stopped me playing with anything but basic tg2 clouds for too long! No more! No more, I say! See you in a month! ...

To visit Nehg' In-Ska', that quaint little Gàidhlig island off the coast of Scotland where this picture was taken, please follow the directions clearly signposted on your journey to the bottom of this thread. You can't miss it, when you come to the big TESCO's it's right past the carpark, to your left. There's usually a guy selling the Big Issue there. Don't talk to him! ;)


I was too late to guess.  I'll punish myself for not having been here on time - NOT.

So this is Disney World.  Can we live here?


I was not that bad with my 3h guess  :P
What you wish to kindle in others must burn within yourself. - Augustine


Oh, sorry, Macgyver, I thought you meant 3 hours with the machine you mentioned above and TG2 cranked to the max. Well, if 3hrs was your guess, you were the closest! Shame the silent bidder got it at a steal in the night. :(

I'm working on explosions from inside TG2 at the moment, post soon, rendering...


To bring this back, briefly: Someone on Renderosity told me to look at this image upside down(another few people said 'wow!!!!' 'georgeous!' etc. etc. etc. but this one comment was great, and true.).

Upside down, I see it like a nasty sulfurous place with rancid milky water and rusty growths of fungal-diseased coral. Ewwwwwwww! What have I DONE?! I'm appalled! Absolutely appalled! ;)  :D



1stly, superb image, both the right way up and upside down. (it does change it into a completely different pic  ;D )
2ndly, don't worry, the big issue seller isn't there today, and I certainly wouldn't talk to him even if he was.... I heard that he was a multi- millionaire who is dropped off there every morning in his chaufer driven Bently....

I love the smell of caffine in the morning