The Khronos Group has released of a set of new Physically Based Rendering (PBR) material extensions for glTF. These new extensions for Clear Coat, Transmission and Sheen build on the existing PBR capabilities of glTF 2.0, and together with additional upcoming extensions, are creating a powerful, interoperable, physically-based material model for the glTF ecosystem. Read all the details of the announcement:
https://www.khronos.org/news/press/khronos-releases-wave-of-new-gltf-pbr-3d-material-capabilities