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SSSdusty air setting how to do it myself?

Posted: Thu Oct 29, 2009 3:17 am
by djegoo
hello all.
Here is a really great Render from the Finished artwork forum done by enricocerica , and i would like to learn how to set the material myself in the skindigo material editor.

I downloaded the FOG igm in the database, but i find it too dusty,i mean the density is to high and we don t see far enough, this is the reason why i would like to do it myself.

here is the result. I would like to know what values to set where

i hope you can help me!

Re: SSSdusty air setting how to do it myself?

Posted: Thu Oct 29, 2009 4:53 am
by djegoo
http://www.indigorenderer.com/materials ... iew_source
oh i think i start to understand after some hours of toggling.


<?xml version="1.0" encoding="utf-8"?>

<scenedata>
<medium>
<name>Material</name>
<precedence>2</precedence>
<basic>
<ior>1</ior>
<cauchy_b_coeff>0</cauchy_b_coeff>
<absorption_coefficient_spectrum>
<rgb>
<rgb>0.1 0.1 0.1</rgb>
<gamma>2.2</gamma>
</rgb>
</absorption_coefficient_spectrum>
<subsurface_scattering>
<scattering_coefficient_spectrum>
<uniform>
<value>0.0315479</value>
</uniform>
</scattering_coefficient_spectrum>
<phase_function>
<uniform/>
</phase_function>
</subsurface_scattering>
</basic>
</medium>
<material>
<name>Material</name>
<specular>
<transparent>true</transparent>
<internal_medium_name>Material</internal_medium_name>
</specular>
</material>

</scenedata>

i found that on the "source" button page. so i made the relation between this.......stuff..... and the interface.
so, should it should be a Specular, with IOR set to 1. What i don t know is which value to lower if i want it less dusty? Precedence? cauchy B? Subsurface scattering? Spectrum? :cry:

Re: SSSdusty air setting how to do it myself?

Posted: Thu Oct 29, 2009 9:25 am
by OnoSendai
scattering coefficient basically controls the amount of scattering, or 'dustiness'.

Re: SSSdusty air setting how to do it myself?

Posted: Thu Oct 29, 2009 10:47 am
by djegoo
YAH it is what i noticed and tryed to understand quite empirically and by reading the user manual. i just wanted to have an idea of the value to input i think i am quite satisfied with what i found.

here is the result with the setting i posted just above. the scene is not interesting but i just wanted to learn and maybe inform future newbies who will want to do it too :mrgreen:

Re: SSSdusty air setting how to do it myself?

Posted: Thu Oct 29, 2009 9:58 pm
by Pibuz
Hi djegoo!
We SketchUp users have a more powerful tool to control the fog: it's called...FOG! :lol: :lol:
You know that you can set a foggy environment within sketchy if you use the "Fog window" (window->fog): just click the "display fog" check! Set the left cursor to zero and adjust the right cursor to fit your needs.

In SU no need to download materials, no difficult settings 8) Thanks Whaat! :D

Re: SSSdusty air setting how to do it myself?

Posted: Thu Oct 29, 2009 11:46 pm
by djegoo
HI PIBUZ!

yeah i tryed it, it works perfectly, but i don t understand why, it is soooo long to render. or maybe i did something wrong. but gonna try again with the fog!

maybe i should have put exit portals and that s why it was so long.
gonna give it a try again.
Your wise advices are always welcome :D

EDIT : oh, yes, i just forgot to put the exit portal :roll: but actually when i set it at the minimum with the Fog window i still find it a chouya too dusty :D
anyway, i know both methods now ! still good to know

Re: SSSdusty air setting how to do it myself?

Posted: Fri Oct 30, 2009 1:49 am
by Whaat
SkIndigo exports the fog color as well. So make sure your fog color is set to white. Otherwise, it may be too 'dusty' for your tastes.

Re: SSSdusty air setting how to do it myself?

Posted: Fri Oct 30, 2009 2:27 am
by djegoo
yes, i just noticed that changing the color worked!
shall i consider the fog as a material, i mean set it at 100% white? or ~85 like any other white?
thanks for yer answerrs! gonna try it to compare.

EDIT : seems to be the same, just needed to add more exposure when setted to 85 luminosity.
I think in fact i just forgot the xit portal when testing the fog at the very beginning....

Re: SSSdusty air setting how to do it myself?

Posted: Fri Oct 30, 2009 8:48 am
by Whaat
It's not a bad idea to set it to 85% white. Otherwise, you will have no absorption which would result in more light bounces and longer render times.