Hi, Chromium VR (55.0.2869.0) is also NOT working for me on Sketchfab with HTC Vive on Windows 10.
Browser goes into split view okay, but there's no tracking and the HMD stays in the Vive Arena.
A possibly useful warning is..
embed?ui_watermark=0&ui_stop=0&tracking=0&ui_snapshots=0&internal=1&autostart=1&ui_infos=0:1 Uncaught (in promise)
DOMException: Access to VR devices is not allowed in this context.
viewer-4073430….js:49 no hmd device provided to the viewer!
While we're in "things are changing a lot" world, it'd be awesome if everyone listed precisely which versions/platforms you have Sketchfab VR working on.
If instead I use ChromiumVR 54.0.2823.0 from Brandon's Archive folder (around 7 Aug 2016) on webvr.info, Sketchfab in WebVR mostly works okay. I still find the wand controller a bit hit and miss.