@Pumeco: "Looks good, Teyon, though now I have to look-up PBR, DDO, 3D0, and Quixel, none of which I even know about.
Well, I've heard the name Quixel before, rings a bell, but that's about it."

Quixel is only compatible with Photoshop. Here's a quote from their FAQ page:

Q: Does dDo/nDo2 work with GIMP, PaintShop Pro, Corel Draw or the like?
A: The tools are compatible with Photoshop (CS3-CS6, Standard and Extended editions) as they utilize Photoshop's extremely powerful scripting engine for processing, currently unmatched by other image processing applications. (source: http://www.quixel.se/usermanual/ddo/doku.php?id=faq)