[osg-users] Oculus+OSG

[Jan Ciger]

On Tue, Sep 8, 2015 at 4:26 PM, Björn Blissing <bjorn.blissing at vti.se> wrote:

> In the "Oculus Rift Developer Guide" you will not find a word about asynchronous time warp. They are only saying that the compositing framework is handling distortion, timewarp, and GPU synchronization, whatever that incurs...

It is described in this post (that you have mentioned too):
https://developer.oculus.com/blog/asynchronous-timewarp-examined/
It was one of the reasons they had to go to Nvidia (the other being
the direct mode support), because it is not possible to implement it
without driver support.

>
> I don't know if this means that Oculus currently are doing pure "original timewarp", pure "asynchronous timewarp" or a combination of the two (since its all happening inside the closed source part of the Oculus SDK). But the feature shown in the videos is currently available.

Yes, that is the asynchronous timewarping in the new SDK. The
"original timewarp" does not have any effect on framerate (you still
need to render every frame + you are rendering the warping at the
end), only on perceived tracking latency. The difference is explained
in that blog article by their chief software architect. The original
timewarping by J. Carmack is described here:
https://web.archive.org/web/20140719085135/http://www.altdev.co/2013/02/22/latency-mitigation-strategies/


Regards,

J.