I did a gltf 1.0 exporter from slicer a while back . I've been wanting to factor it out into an independent library and upgrade it to gltf 2.0. Most of the code is generic VTK, but with some extra context extracted from Slicer data structures. Here's a web page  that shows an exported scene displayed with a-frame (also works with WebVR if you have it).
I would be glad to see this move forward - I was just a Qt event yesterday and the new KDAB Kuesa  tools use gltf 2.0 with QML in ways that could be fun.