CGTalk - nearly gradientless sky with "spectral model"

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MarioC

11-18-2008, 09:50 AM

vue 6.6: has anybody a clue how to create a deep blue sky rendered with "spectral model", without this harsh gradient? e-on writes in his documentation that "spectral model" renders the light through air like it behaves in reality, but in reality there are also blue skies without red or white horizons and dark blue areas on the highest "point" of a sky-dome (i know that we austrians are a bit different, but i have tons of photos of nice winter-landscapes in the alps where the whole sky has only one shade of blue ;) ).

i played around for hours, setting the values of sky mean altitude to real values (5.5km) and so on. scaled my world to real scale values (a DEM with 50*50km) and altered the arieal perspective to 1. by doing this i get an extremly white glowing horizon. i tried to compensate this with decay, but no setting was "strong" enough to get rid of this glowing, but let the landscape disappear in its deep fog.

i also tried "standard model", but with this rendering method you better shouldn't use clouds because they look really awkward (and yes, you guess right: in my scene are a lots of clouds). :cry:

thanks in advance for any tipps :)

Hartoz

11-18-2008, 07:48 PM

This is really easy to do, so don't fret ;-)

In the Atmosphere Editor, set the Sky Colour to a very dark Blue, and maybe drop the Decay colour as well.

The rest is controlled by the light colour and and ambient light colours and thier intensities.

You will also find that changing the altitude of the Camera will also change the sky colour (going all the way to black (and stars if they are enabled)).

If you still cant do it, PM me and I will send you an Atmo when I have time.

phamarus

11-19-2008, 07:04 PM

I think it´s possible to do..if you know how to do it and exactly how blue and deep do you want it..can you show a photo of something similar.`

you have to check each and every one of the atmosphere settings and learn how they affect each other, try and turn haze of, or turn down haze altitude, lower sky mean altitude, lower decay amount, lower decay mean altitude.
probably raise scattering anisotropy very high.

the sky color is important to..and also haze color affects alot.

post a picture of what you got so far, and if you have a reference photo of how you want it to be, and Ill see if I can get something similar.
edit..
Also remember that the sunposition is important aswell to give it a deep sense of atmospheric.
Michael

phamarus

11-19-2008, 07:12 PM

well and to help remove the glow at the horizon..have a very low sky density and you could also make sure your ambient light has a darker color or value that might help.
you can even change the decay color to a bluish tone..

I don´t think you should expect this spectral atmosphere to give complete fully realistic behaviors..it´s really an artificial mockup that is getting close thou.

Michael

MarioC

11-21-2008, 08:46 AM

thanks a lot for your tipps, especially hartoz. i tried it as you said, got really fast a nice deep blue sky, but couldn't tweak the lightning in a way to get the landscape as nice looking as before, so i played a bit around and found another way, on the basis of hartoz hint:

i create a very dark blue sky with 5,5km mean (i use real world scaling) and a decay of 10km with a medium blue colour. then i adjust the oversaturated, a bit dark sky with the lightning, fog and haze.

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