glTF

glTF, sometimes called the JPEG of 3D, is a format designed for transmitting models rather than editing them. It stores geometry, materials, textures and animations in a compact structure that browsers and game engines can load quickly. The specification is open and maintained by the Khronos Group.

A glTF can be several files, a JSON description plus textures and binary data, or one file, in which case it is called GLB. Web delivery almost always uses GLB.

The format's material model is physically based, meaning it describes how a surface reacts to light rather than what colour it is, which is what lets a fabric look right in any lighting the viewer or the AR scene provides.