2024 week #33: SL CCUG summary

Posted on by Inara Pey
Grauland / Corsair Island, July 2024 – blog post †

The following notes were taken from my audio recording and chat log transcript of the Content Creation User Group (CCUG) meeting held on Thursday, August 15th, 2024.

Meeting Purpose

  • The CCUG meeting is for discussion of work related to content creation in Second Life, including current and upcoming LL projects, and encompasses requests or comments from the community, together with related viewer development work. This meeting is held on alternate Thursdays at Hippotropolis.
  • Meeting dates and times are recorded in the SL Public Calendar, and they re conducted in a mix of Voice and text chat.
  • The notes herein are a summary of topics discussed and are not intended to be a full transcript of the meeting.

Official Viewers Status

The Atlasaurus RC (object take options; improved MOAP URL handling) updated to version 7.1.9.10326512121,  on August 14th.

The other viewers in the pipeline remain as:

  • Release viewer: version 7.1.8.9375512768, formerly the Graphics Featurettes RC viewer dated June 5 and promoted June 10th.
  • Release channel cohorts:

Upcoming Releases – Change In Priority

As a result of PBR-related issues (see the section Performance Issues, below), the priority of upcoming viewer releases has changed.

  • The next planned viewer promotion was to have been the dedicated WebRTC Voice viewer.
  • The plan now is to prioritise a “more ambitious” viewer which will include the WebRTC updates and a number of high-level bug fixes related to performance (e.g.  a major vertex buffer fix, which although specifically targeted at Mac users, could help others on systems with integrated graphics).

Graphics / glTF

PBR Terrain Painting – Cosmic Linden

Summary
  • An in-development project. Current intent:
    • Provide a means to support the four PBR materials currently used in SL for “terrain painting”.
    • Will allow materials to be defined in their X,Y co-ordinates within a region by using a paint map, rather than having them defined by elevation defined in a height map. This will allow where grass or rock or stones or dirt, etc., appear within the region. providing much more flexibility in how terrain appears / changes.
    • Terrain painting will use the same permissions as terrain texturing (so if you have terraforming permissions, then tertian paining is possible; if you have the appropriate region permissions, you can define the PBR materials for the region.
    • Region owners / estate managers will have the ability to select whether the texture / heightmap is available in a region or whether the region uses terrain painting via a toggle switch in the Region floater. If Terrain painting is enabled at the region level, parcel holders (if I am understanding correctly) will be able to opt out / in.
  • Other points of note:
    • LL prefer to limit terrain painting to the four available slots at region revel, rather than allowing fully customisable swatches / slots at parcel level, as the latter presents “non-trivial issues” for terrain texture handling /loading.
    • Terrain painting will require a new entity to be introduced. Exactly what form this will take is still being discussed internally; it is unlikely to be a new asset type.
  • Much longer term options being considered for this capability might be to:
    • Allow prims to act as part of the terrain, inheriting the materials of the terrain, whilst still allowing the prim to be sized and shaped.
    • Perhaps allow the terrain within a region to be replaced by “something” else created externally to SL and then imported.
    • Neither of these ideas are currently being pursued beyond possible ideas / options.
Status
  • Cosmic believe she is getting close – perhaps another couple of weeks – to having an initial viewer build with the capability.
  • This initial build will allow terrain painting purely on the viewer-side; there will be no support for saving changes on the simulator; this will come as the work continues to be developed.

Transmission / IOR – Geenz Linden

  • Transmission and Index of Reflection (IOR)  will provide:
    • Both refraction and “blurry” refraction suitable for things like frosted glass surfaces.
    • Dispersion, allowing chromatic aberration, allowing the RGB channels to “separate out” based on a certain factor.
    • Volume, allowing an object surface to be tinted at different surface thicknesses .
    • Geenz is currently wrapping this work to get it into the Develop branch of the viewer following an internal demonstration at the Lab.

General Discussion

Performance Issues

  • It’s been confirmed that the potential for performance drops was missed within the code Firestorm took to integrate into their PBR viewer offering, and given they have the largest share of users (particularly those on low-to-mid range systems – e.g. those with 16Gb of RAM or less, and mid-to-low spec GPUs or with integrated graphics), their users have been the hardest hit with performance issues.
    • As a result, Linden Lab is now working with Firestorm to resolve the current issues.
    • As noted above, Linden Lab is now working to prioritise the release of a viewer with a number of fixes and updates aimed at improving / restoring viewer performance.
    • In the interim, the recommendation is for anyone experiencing severe performance issues to roll back to a pre-PBR viewer release.
    • Further, given that fixes beyond those currently being prioritised by LL will take time to surface, and the fact that there will continue to be systems that struggle with PBR, Firestorm has stated that version 6.6.17 of their viewer (the last pre-PBR release) will not be blocked per standard policy, but will remain available on as “as is” basis (e.g. not subject to bug maintenance or update with new features).
  • Fixes LL are looking to get out after the “prioritised” viewer has been released include:
    • Addressing  issues with the texture pipeline.
    • Fixing an issue whereby viewers on systems without dedicated video memory continually allocating available system memory to textures until all available system memory is consumed and the system suffers “performance death” until restarted.
    • A fix from the Alchemy team for an issue wherein if Mirrors are disabled in a viewer session, they continue using system resources until the viewer is restarted.
  • There will be “some form of communications coming out soon” to help inform people who are having a negative experience with PBR about what is going on to help alleviate issues.

In Brief

  • As far as enhancing rendering / shaders is concerned, the focus currently is on getting a working glTF scene implementation first, then working out what to backport to materials in inventory for applying to prims / non-glTF meshes. The will provide a good frame of reference when backporting materials to legacy objects and help maintain a consistency of appearance.
  • The meeting was overtaking by an extended discussion / diagnosis of a issue with hair which is becoming increasingly notices (hair appearing to “clump” or get blurred which does not appear to be directly related to colour alpha blending).
    • The problem is in part exacerbated by the fact the most SL hair is No Mod; so issues cannot be easily user-addressed.
    • No clear solution to this was presented, and the conversation is liable to continue, so will update if / when a way forward becomes clearer.
    • One idea floated, but will require a lot more internal investigation before LL move one way or the other, is to potentially add flags that will allow certain parameters within No Mod objects to be modified where it makes sense for them to be modifiable.
    • Expect further discussion on this.

Next Meetings

† The header images included in these summaries are not intended to represent anything discussed at the meetings; they are simply here to avoid a repeated image of a gathering of people every week. They are taken from my list of region visits, with a link to the post for those interested.

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Published by Inara Pey

Eclectic virtual world blogger with a focus on Second Life, VR, virtual environments and technology.