Substance material analogues?

Question

3D

Are there any standardized tools for procedural creation of materials? I'm not interested in software (like NeoTextureEdit or Substance Designer), but in libraries / tools that can be integrated into the engine with OpenGL.
The idea is not to produce a lot of textures, but to generate them on the fly (for example, based on several textures, you can get many others that can be generated on the client side). The same Substance Designer has its own format, everything is based on nodes, although similar is used in UE4, but no open source solutions were found

Answer 1

I immediately google this:
libnoise.sourceforge.net/examples/textures
https://www.reddit.com/r/proceduralgeneration/comm... (a reddit discussion of a question very similar to yours).
In addition, the entire demoscene lives on procerud generation, you can google tools or docks from well-known demogroups ( Conspiracy , Farb-rausch ), maybe you will find something useful.