It's a preferred file type, specifically for materials and animations.
We are actively working on this!
Here is another update, planned for version 0.80 - Add support for Roughness/Metallic in GLTF models https://github.com/highfidelity/hifi/pull/14890
We are working on this, but it will be in the 81 release time frame.
Scheduled for v0.79.0
Update: We are working on this now. We have a couple developers already working on this. In particular updating our file parsing code to support the latest gltf features, as well as support for handling materials in the gltf file. We don't yet have a release date for this. But we currently think we'll release it in the 81 time frame.
@ZappoMan: <happydance />
We currently support GLTF models as entities and we are chipping away improving support for glTF. As many users may know already, this feature request is tricky as the standards for glTF is evolving. We plan to break this feature request into smaller sub-feature requests so that we can better apprise users of our progress.
@Emily Iwankovitsch: It's great to know that High Fidelity recognizes this as an important feature!
Per evolving specs, it's not that tricky. Let's just say you're targeting glTF 2.0. The spec for that is pretty solid at this point. If you can at least import Khronos validated glTF meshes that include armatures, animations and blendshapes, you ought to be most of the way there.
Static meshes work, but it isn't unknown for the viewer to crash when trying to load one, and the ATP service seems a bit hit or miss about glTFs. In addition, the oven doesn't yet support baking glTF.
For creators using Blender, this really, really isn't an optional feature. With the removal of the old Blender Render Engine, glTF is currently the ONLY exporter Blender 2.8 has that can export a mesh with PBR materials. What more, it's probably the only exporter that is actually fully compatible with High Fidelity's PBR materials.
I recently ported a scene into Blender 2.8's Eevee renderer, and what I saw there looks a LOT more like what I might expect to see in High Fidelity. Supporting as much of the GLTF specification as possible is a must as this is a format that has strong support in the Blender community.