Category: SL Tech

The following notes were taken from my audio recording and chat log of the Content Creation User Group (CCUG) meeting held on Thursday, January 21st 2021 at 13:00 SLT. These meetings are chaired by Vir Linden, with dates available via the SL Public Calendar.

The venue for meetings is the Hippotropolis camp fire.

SL Viewer

The Dawa Maintenance RC viewer updated to version 6.4.12.555058 on Wednesday, January 20th signalling the issues within the build process that had stalled viewer updates have been cleared. However, at the time of writing all other viewers in the current pipelines remain unchanged:

• Current release viewer version 6.4.11.551711, formerly Cachaça Maintenance RC viewer promoted on November 12 – No Change.
• Release channel cohorts (please see my notes on manually installing RC viewer versions if you wish to install any release candidate(s) yourself):
  • Project Jelly viewer (Jellydoll updates), version 6.4.12.553798, January 7, 2021.
  • Custom Key Mappings project viewer, version 6.4.12.553437, January 7, 2021.
• Project viewers:
  • Love Me Render (LMR) 5 project viewer, version 6.4.12.553511, issued on January 7, 2021.
  • Simple Cache project viewer, version 6.4.11.551403, November 12.
  • Legacy Profiles viewer, version 6.4.11.550519, October 26.
  • Copy / Paste viewer, version 6.3.5.533365, December 9, 2019.
  • Project Muscadine (Animesh follow-on) project viewer, version 6.4.0.532999, November 22, 2019.
  • 360 Snapshot project viewer, version 6.2.4.529111, July 16, 2019.

General Viewer Notes

• A more comprehensive viewer update is in my Friday, January 22nd TPV Developer meeting summary.

Viewer Caching

• LL are in the process of overhauling and improving the viewer’s cashing mechanisms.
• There is already a Simple Cache  project viewer that is available (see the viewer list above). This will be progressing to RC status soon.
• A further project by Callum Linden is to improve the caching and loading of textures within the viewer. No ETA at present as to when a project viewer for this will surface.
• Mention was made in 2020 about detaching the viewer UI rendering from scene rendering in order to improve viewer performance. This work is still in the discussion/ initial development stages.

Viewer Rendering Situation (Moving from OpenGL)

Work on updating the viewer’s rendering API to something more recent than OpenGL (which is to be deprecated by Apple anyway) has hit an issue. Vulkan had been looked to as a replacement for OpenGL. However

• Logging added to the viewer to assess the capabilities of users’ home systems has revealed that around 20% of existing Windows users have systems that cannot support the Vulkan API (e.g. due to their GPU – notably those with Intel graphics). However, this figure is mixed:
  • It may be conservative, as there are users who are accessing SL with older viewers without the necessary logging, so it could be higher, or
  • The data isn’t currently granular enough to to differentiate between users running on hardware that cannot support Vulkan and those who have suitable GPUs, but simply haven’t updated their drivers.
• This means the work on any potential move to an API change has paused while LL assess options.
• One course of action might be to add some form of abstraction layering in the viewer, such that those able to support a more recent API do so,whilst older systems continue to use OpenGL – but decisions of direction / options have yet to be finalised.
• Another issue with updating the rendering API is the risk of content breakage if an incoming API handles some rendering features in a substantially different manner to OpenGL.
• One aspect related to systems used to access SL lies within LL’s own Recommended specs page, which continues to list GPU options that are well out-of-date. For example, the basic “recommended” Nvidia GPUs are listed as GeForce 9 series / GeForce 200 series, which ceased being supported by Nvidia in 2016.

ARCTan

Project Summary

An attempt to re-evaluate object and avatar rendering costs to make them more reflective of the actual impact of rendering either in the viewer. The overall aim is to try to correct some inherent negative incentives for creating optimised content (e.g. with regards to generating LOD models with mesh), and to update the calculations to reflect current resource constraints, rather than basing them on outdated constraints (e.g. graphics systems, network capabilities, etc).

As of January 2020 ARCTan has effectively been split:

• Viewer-side changes, primarily focused on revising the Avatar Rendering Cost (ARC) calculations and providing additional viewer UI so that people can better visibility and control to seeing complexity.
• Work on providing in-world object rendering costs (LOD models, etc.) which might affect Land Impact will be handled as a later tranche of project work, after the avatar work.
• The belief is that “good” avatar ARC values can likely be used as a computational base for these rendering calculations.

Status

Focus on this project was reduced due to the to concentrate on the Uplift project work, so the last couple of months of 2020 saw little direct progress. Vir hopes to be able to turn his attention back to it “before too long”.

In Brief

• As is common for the start of a year, priority lists are currently being reviewed and updated.
• Graphics updates: as well as the current LMR 5 project viewer with fixes for graphics issues, the Graphics team are also working on other issues, such as rainbows having the colour spectrum inverted  (i.e. appearing as VIBGYOR rather than ROYGBIV). However, it is until to fix the sorting issue that causes the Moon to appear in front of rainbows.

Date of Next Meeting

• Thursday, February 4th, 2021.