These files demonstrate new X3Dv4 features related to Physical Based Rendering and related lighting/texturing "upgrades" of X3D.
See https://github.com/michaliskambi/x3d-tests/wiki/Specification-changes,-to-include-PBR-and-related-features for details. Upcoming X3Dv4 specification will have precise definitions of these nodes.
Unless otherwise specified in AUTHORS.txt files, content here is copyright by Michalis Kamburelis, licensed on Permissive Apache 2.0 license (see the file ../LICENSE in this repo). Feel free to modify and reuse. Contact me if you'd like an even more open license, if it's for the good of Web3D standards -- I'll probablly be OK with this.