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Issue 831619 link

Starred by 2 users

Issue metadata

Status: Available
Owner: ----
Cc:
Components:
EstimatedDays: ----
NextAction: ----
OS: Android
Pri: 2
Type: Bug
Proj-XR
Proj-XR-VR

Blocking:
issue 837646



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VR UI performance: Explore reduction of background rendering cost

Project Member Reported by cjgrant@chromium.org, Apr 11 2018

Issue description

The UI draws a full-screen background.  Ignoring any overdraw concerns, simply drawing the bakground is expensive.

Some quick checking has been done to try and reduce it's cost, but not an in-depth dive.  We should do that dive, and take into account:

- Comparing this cost to that of a full-screen rect (which is also expensive, and *should* be roughly equivalent)
- Cost of the math, texture sampling, etc (these don't seem to have a big impact, according to initial testing)

 

Comment 1 by tiborg@chromium.org, Apr 13 2018

Labels: -M-67 -Hotlist-VRB-MVP M-68 Hotlist-VRB-MVP-Next

Comment 2 by bshe@chromium.org, Apr 18 2018

Owner: bshe@chromium.org
Status: Started (was: Available)

Comment 3 by bshe@chromium.org, Apr 27 2018

Blocking: 837646
Owner: acondor@chromium.org
The current shader does branching for each color channel. I experimented replacing those branchings for a single step call. It appers that there was no noticeable performance improvement. Perhaps the fact that the shader is only used once makes the change unworthy.
Status: Available (was: Started)
In another experiment, I tried to move calculations from the fragment to the vertex shader. It didn't make any significant difference either.
Owner: ----
Labels: -M-68 M-69
Cc: -vollick@chromium.org -tiborg@chromium.org -cjgrant@chromium.org cassew@chromium.org elalish@chromium.org
Labels: -M-69

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