Dither Circles (Composition by gtoledo3)

Author: gtoledo3
License: Creative Commons Attribution-NoDerivs
Date: 2011.10.08
Compatibility: 10.4, 10.5, 10.6, 10.7
Required plugins:

I was looking at Toneburst's port of a webGL crosshatch shader, and I thought the idea of writing different fragment colors and maybe shapes, depending on luminance, was really interesting.

I setup this shader to draw circles that are dependent on luminosity from depth channel.

For four steps of depth, you can control the inner/outer color of the circle, control the interpolation between inner and outer color, void out an area in the middle of the circle (or make it bigger than the outer circle radius, to draw a "smaller" dot than the main circle size).

I don't know if it's really appropriate to call it a dither shader at this point, but I did start with the the crosshatch mono - I deleted all of the "if" stuff after each luminance step, and inserted the code to draw the circles, which was based on this example @ http://people.freedesktop.org/~idr/OpenGL_tutorials/03-fragment-intro.html

The "inner circle" discards kind of "build up" in steps. So, if the first Circ_Inner has a value, all of the subsequent ones will have holes too - you can "add" in bigger holes, or change inner/outer values to kind of tweak around that. It was easier than setting up more conditional statements, and this was just a fun endeavor anyway. :-)

gtoledo3's picture
Re: Dither Circles (Composition by gtoledo3)

After twiddling with the basic concept more, I'm getting some cooler results! Here, I'm just using luminance as a texture mixer (using some stills from lunaquatic from the shadertoy collection).

FourTexme.png383.67 KB
LuminanceMixer GLSL.qtz1004.69 KB

cybero's picture
Re: Dither Circles (Composition by gtoledo3)

This a really playful setup. Been feeding the video input with Quick Time Player [Kindepainter GLSL movie] and feeding the Colour inputs from a randomised HSL iterator patch. Great results :-).

dither circles with movie.png
dither circles with movie.png341.42 KB

jersmi's picture
Re: Dither Circles (Composition by gtoledo3)

Cheers to your playful endeavor. Fun! Wondering about disrupting the grid in some way, like making circles scale and group according to luminance edges....