I’m a big fan of GIMP and Inkscape. I like the knowledge that they will always be there and that if the need arises, I can modify them. I have been interested in writing scrips, and also in generating textures. Below is an end result of a granite texture I generated using gimp and G’MIC.
The first part was figuring out how to generate some sort of starting texture. There didn’t seem to be a good way to generate blobs, but using some abomination of band-pass filters of noise, Gaussian blurs, and thresholds I got something that kind of works.
Honestly, I have no idea what I am doing. I vaguely understand what I did and how the values change it, but I am basically just making it recompute until I find something that I like.
After that it is just me messing around. I didn’t record what I did for the one at the intro, which is too bad because i spent something like three hours on it and don’t remember all of it. I show you how I made a new texture though.
I take the layers from the output of the script and adjust the opacity so that I get some combination of what I want. Then I add some noise and Gaussian blur (sort of a repeating pattern here. When in doubt, add noise and blur!)
It sort of looks a bit like granite, but we can do better. Run the blob creating script again, and then enlarge it by 200%.
Then we add some color and adjust the opacity! We may even add some noise and some blur! Play with the color balance! Adjust the brightness, contrast, hue and saturation. You know what you are doing as much as I do! And then we get something that actually doesn’t look that bad!
Most granite seems to have some natural color variation. I find generating some plasma and reducing it to basically a single hue, then adjusting the opacity helps it to look more real.
Hopefully you like what you made, if not there seem to be countless resources online for textures. They also don’t require as much time to obtain, but where is the fun in that!