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Voronoi ISL Shader

Posted: Thu Oct 07, 2010 10:15 am
by galinette
Not as difficult as I first thought!

Do you see some applications of it for real world materials? Maybe stone walls or the like.

Next step is to have a thin border between cells

Etienne

Re: Voronoi ISL Shader

Posted: Thu Oct 07, 2010 10:48 am
by galinette
Here are some other example applications of this shader

Re: Voronoi ISL Shader

Posted: Thu Oct 07, 2010 10:54 am
by OnoSendai
That's very cool.
I'm trying to work out how your code works :)
One tip: you can use the < operator instead of lt().

Re: Voronoi ISL Shader

Posted: Thu Oct 07, 2010 11:25 am
by Zom-B
great work galinette!!!

This is something that should be integrated directly in Indigo, just like FMB & perlin Noise!

Re: Voronoi ISL Shader

Posted: Thu Oct 07, 2010 11:52 am
by OnoSendai
Zom-B wrote:great work galinette!!!

This is something that should be integrated directly in Indigo, just like FMB & perlin Noise!
Hmm, what would the shader return? Index of cell?

Re: Voronoi ISL Shader

Posted: Thu Oct 07, 2010 12:56 pm
by Zom-B
OnoSendai wrote:Hmm, what would the shader return? Index of cell?
Noise shaders are barley used pure as they are in material creation. Having a simple call via ISL would simplify usage for regular users.
From the control of cell size over to a 0 to 1 scale for "smoothness" off the cell inner to a border scale etc.

From the user point of view I see this integrated into the Exporters just like Yves did with gradient & noise in Cindigo :)

Re: Voronoi ISL Shader

Posted: Thu Oct 07, 2010 1:52 pm
by CTZn
Perhaps a (edited:) distance between points ? A distribution from ordered to random would be cool (optionally seeded).

For a realistic, parametric reptile skin, both the distances between points and their randomness in distribution should be non-wavelength dependent parameters, that is float or grayscale data driven. Me thinks :)

I mean, with an actual reptile mesh. Painting the scales size and randomness would be a great option ! Argh, can't help pushing nevermind me :D

Re: Voronoi ISL Shader

Posted: Thu Oct 07, 2010 7:48 pm
by galinette
Zom-B wrote:This is something that should be integrated directly in Indigo, just like FMB & perlin Noise!
Absolutely!! This is a very good primitive for many shaders
OnoSendai wrote:Hmm, what would the shader return? Index of cell?
I could write you some specs!

I see at last two interesting : the center of cell (vec2), the distance to center of cell (real)
The two last images use the latter, I'll upload soon.

Etienne

Re: Voronoi ISL Shader

Posted: Thu Oct 07, 2010 7:50 pm
by galinette
CTZn wrote:Perhaps a (edited:) distance between points ? For a realistic, parametric reptile skin, both the distances between points and their randomness in distribution should be non-wavelength dependent parameters, that is float or grayscale data driven. Me thinks :)
That's exactly what the shader used in the two last images do (modified since the first one). I'll upload soon as soon as I have more time to work on this...

Re: Voronoi ISL Shader

Posted: Thu Oct 07, 2010 8:17 pm
by OnoSendai
galinette wrote: I could write you some specs!
Sure, that would be great!

Also If I had more of an idea how the Voronoi cells would be used in shaders, that would help.

Re: Voronoi ISL Shader

Posted: Thu Oct 07, 2010 9:37 pm
by galinette
[/quote]Also If I had more of an idea how the Voronoi cells would be used in shaders, that would help.[/quote]
I will post some material using them soon...

Example picture:
http://www.google.fr/imgres?imgurl=http ... 4Qb1vrnIBg

Etienne

Re: Voronoi ISL Shader

Posted: Thu Oct 07, 2010 9:56 pm
by Zom-B

Re: Voronoi ISL Shader

Posted: Thu Oct 07, 2010 10:33 pm
by galinette
I love the dry mud idea!

Etienne

Re: Voronoi ISL Shader

Posted: Fri Oct 08, 2010 1:21 am
by CTZn
Mostly, it is usefull for rural/natural structures, walls an stone paths. A simple application could be as a blend between a stone and a mortar material:

http://www.tandtmasonry.com/Stone%20Pedestal.JPG

http://www.google.com/imgres?imgurl=htt ... =104&ty=43

Could cells indices play a role in affecting blended shaders like for the above (per cell hsv) ?

Re: Voronoi ISL Shader

Posted: Fri Oct 08, 2010 2:33 am
by galinette
Yes, of course. Thats quite straightforward.

The only thing that is somewhat complicated is to make:
- The border between cells
- The irregularness ( non straight borders )

Etienne