Just something I concocted from lessons learned in the quest of creating cobblestone mosaics.

ref: http://www.fontplay.com/freephotos/sixt ... 06-016.jpg

That is so cool ! Don't you want to explain how you did it (or even better, write the G'MIC code to do that ) ?

Actually, though I used a lot of the cobblestone tut outline, I used Inkscape Gel and a few GIMP layer properties and texture blends to get this effect David. Pretty convoluted for a tut (i.e., may not be able to get the same result twice; lol). I believe one of the tricks used Gradient Norm placed on top layer set the layer property to Grain Extract to enhanced the 3D raised result. That was pretty much the only additional G'MIC trick besides what I had already outlined in the cobblestone tut. As you already know, coder I'm not. lol

OK David. Here's a result without the Inkscape step (which I created the glaze/glass look). First, after creating the cobblestone like i outlined in the cobblestone tut, I dup and run G'MIC's Gradient Norm (played with sliders to get this result).

the inkscape step is maybe a bitmap filter ?
if yes maybe Ronounours may adapt for gmic

i have no doubts that inkscape has excellent bitmap filters but since is not a bitmap editor those filters could be not too complex , the code is open,so should be possible create analog gmic filter

Here i may only offer to trace the codes (and maybe dig a bit more to trace the algorithms ) if you name the filters,no much hope i may do more but maybe Ronounours is interested

That image looks really cool Lyle.

Nearly all the filters in Inkscape are bitmap filters PC (on vectors, they operate on the fill color) which is why I wish someone would port them to GIMP. Also thanks for the comments Rod.