A development of Second Life is introducing Physical Based Rendering (PBR) materials based on the glTF specification. Some links and resources are in my earlier blog post.
Test Materials with Metallics, Lights and Emission
Ready Player Me Avatar with All Channel PBR Materials
Bistro Interior by Nagachief Darkstone
I tested out some of my previous complex mesh models, which use the old style texturing and shininess. This is how they render in the test PBR viewer without applying any new materials or properties.