vvuk
Add the ability to project DOM VR content into a element
Implement CSS property to specify that a element is to be interpreted as a stereo left/right pair.
This will be used in cases where we want to create stereo rendered output outside of using requestFullscreen.
Based on slack discussion: this is basically allowing an iframe (e.g. the horzion browser frame) to act as a "portal" into another 3D world/view, with the right things happening in each eye. We can look into this, but it will be far down the line.
Yes, this would definitely be useful for that. Could also be used for stereoscopic images and videos.
As long as CSS support is coming back around, I'm strongly in favor of this (though I acknowledge it must be extremely challenging to implement). It could be the best bet to implement seamless transitions between Web VR sites, without having to completely re-think and re-implement the browser UI for VR. It would allow the community to experiment with interaction models before having to commit to one approach built-in to the browser.
I think this feature needs to be paired with a way for a given iframe to determine it's position/orientation relative to the top-level camera, so it can render accordingly. For CSS elements inside the iframe, it might be handled by the browser, but if you have a full-window canvas inside that iframe, you need a way to get the correct perspective.
Update: This looks like it kind of works. We get a stereo view, but the perspective is way off:
Viewable example here: http://caseyyee.github.io/experiment-cssvr-iframe/iframe.html
This is using the builds from May 7.