1196663 - Implement latency measurements

Status: RESOLVED DUPLICATE of bug 1229485

(Core :: General, defect)

Description

[Josh Carpenter [:jcarpenter]]

Measuring latency is important is we want to quantify where we stand and track improvements.

Latency is a critical variable in the perceived-performance of a virtual reality experience. 20ms is commonly-understood to be threshold for "presence" (the point at which the human brain is effectively fooled into believing it is inside a simulation). Latency in this is "motion-to-photon": the full time required for the system to render the latest frame in response to user movement. When latency is too high (+20ms) it creates a noticeable "drunken" effect, wherein the world seems to lag. This can induce discomfort to the point of nausea. 

We will never have full control over total latency, as the renderers of VR platforms like Oculus are a black box into which we dump undistorted frames. But we should do everything we can to reduce the latency of the parts of the pipeline that we do control.

Comment 1

[Josh Carpenter [:jcarpenter]]

The desire here is to implement a means of testing latency of the device-to-Firefox-to-device render loop.

Comment 2

[Josh Carpenter [:jcarpenter]]

Kip, this seems to be a dupe of the newer 1229485 rather than a dependency. Shall we close this in favor of the new bug?