Custom Material Definition Format, File and a Shading Language

[recp]

We must define custom material definition format and file, plus a Sharing Language like Google did for Filament:
https://google.github.io/filament/Materials.md.html#overview/coreconcepts or bsl in banshee3d: https://docs.banshee3d.com/Native/bsl.html

File extension could be .gpumat or .mat or .gkmat or .gmat, .effect ...

Desired properties:

• Provide builtin compiler for that material
• Ability to compile at runtime
• Allow multiple passes
• Support all glTF and COLLADA materials

This project will use gpu (this is private repo for now) library as backend. So GPU library may use .gpumat. Also GPU library may provide a shading language or gk could do that.