2023 week #27: SL CCUG + TPVD meetings summary

[REN] May, 2023 – 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, July 6th, and the Third Party Viewer Developer (TPVD) meeting held on Friday, July 7th, 2023. 

Meetings

  • The CCUG meeting is for discussion of work related to content creation in Second Life, including current work, upcoming work, and requests or comments from the community, together with viewer development work.
  • The TPV Developer meeting provides an opportunity for discussion about the development of, and features for, the Second Life viewer, and for Linden Lab viewer developers and third-party viewer (TPV) / open-source code contributors developers to discuss general viewer development.
  • As a rule, both meetings are:
    • Held in-world and chaired by Vir Linden.
    • Conducted in a mix of voice and text.
    • Held at 13:00 SLT on their respective days.
    • Are subject to the schedule set within the SL Public Calendar, which includes locations for both meetings (also included at the end of these reports).
    • Open to all with an interest in content creation / viewer development.
  • As these meetings occasionally fall “back-to-back” on certain weeks, and often cover some of the same ground, their summaries are sometime combined into a single report (as is the case here). They are drawn from a mix of my own audio recordings of the meeting + chat log (CCUG), and from the video of the TPVD meeting produced by Pantera Północy (which is embedded at the end of the summaries for reference) + chat log. Not that they are summaries, and not intended to be transcripts of everything said during either meeting.

Viewer News

  • The Windows 32 + macOS pre-10.13 RC, version  6.6.13.580794 was rapidly promoted to de facto release status on July 6.
  • The Second Life Project Inventory Extensions viewer updated to version 6.6.13.580656, on July 6.

The remaining viewers in the pipeline stand as:

General Viewer Notes:

  • The Windows 32 + macOS pre-10.13 viewer is the last official viewer supporting either the Win 32-bit version or Mac OS versions prior to version 11. As viewers for 64-bit only and MacOS 11+ become the defacto releases, this viewer (as it is and without further update) will be moved to a side cohort, and used when someone running a pre-11 MacOS release or a Windows viewer incapable of running the 64-bit version of the viewer will receive this version instead.
  • Maintenance T has returned to being the most likely RC viewer due for promotion to de facto release status, now that its high crash rate has (hopefully) been brought under control.
  • The Emoji project viewer is liable to see further improvements to the Emoji picker in the UI.

glTF Materials and Reflection Probes

Project Summary

  • To provide support for PBR materials using the core glTF 2.0 specification Section 3.9 and using mikkTSpace tangents, including the ability to have PBR Materials assets which can be applied to surfaces and also traded / sold.
  • There is a general introduction / overview / guide to authoring PBR Materials available via the Second Life Wiki.
  • For a list of tools and libraries that support GLTF, see https://github.khronos.org/glTF-Project-Explorer/
  • Substance Painter is also used as a guiding principal for how PBR materials should look in Second Life.
  • Up to four texture maps are supported for PBR Materials: the base colour (which includes the alpha); normal; metallic / roughness; and emissive, each with independent scaling.
  • Given the additional texture load, work has been put into improving texture handling within the PBR viewer.
  • In the near-term, glTF materials assets are materials scenes that don’t have any nodes / geometry, they only have the materials array, and there is only one material in that array.
  • As a part of this work, PBR Materials will see the introduction of reflection probes which can be used to generate reflections (via cubemaps) on in-world surfaces. These will be a mix of automatically-place and manually place probes (with the ability to move either).
  • The overall goal is to provide as much support for the glTF 2.0 specification as possible.
  • The viewer is available via the Alternate Viewers page.
  • Please also see previous CCUG meeting summaries for further background on this project.

Status

  • The simulator code is now more widely available on the Main Grid, including some sandbox environments, but still in RC. These regions comprise:
  •  However, it should be noted that:
    • Bug-fixing within the simulator code is also on-going, so those testing PBR materials where the support is available should take note of this.
    • Obviously, to take advantage of these regions (both to upload PBR Materials and to see the new PBR environment lighting + the demonstration objects provided within some the regions, you must be running the PBR Materials RC viewer.
    • The cost of upload for Materials without any textures is free; however, the L$10 texture upload fee is charged on a per texture basis for any included within a PBR material surface (up to four can be included).
    • Any PBR materials content created within these environments which is later rezzed in any region that is not Materials-enabled, will become “material-less” in a non-recoverable way, and will need to be recreated.
    • Because of the above point, until PBR support is fully gird-wide, any attempts to put PBR-enabled goods on the Marketplace will be sanctioned.
  • General bug fixing on the viewer is also continuing, and the spread PBR across the grid is largely down to a mix of bug fixing and getting everything stable, and seeing if any particularly nasty blockers or bug rear up.
  • As an aside, the additional texture overhead for PBR Materials has been one of the drivers behind increasing the amount of VRAM the viewer can use for textures, as also now found within the PBR Materials viewer.

PBR Mirrors

  • This is a follow-on project to the PBR Materials, intended to provide a controlled method to enable planar mirrors in SL (i.e. flat surface mirrors which can reflect what is immediately around them, including avatars).
  • The approach Geenz Linden is taking towards enabling mirrors is to use a “hero probe” concept. In short:
    • With PBR, reflections are generated using reflection probes, per the notes above. These are capped at a maximum resolution of 128×128 per object face; hero probes will be capped at 512×512 per object face, providing a mush higher resolution of reflection.
    • Hero probes are an automated selection process. “Standard” probes cannot be converted to hero probes by manual intervention, nor can they be created.
    • A hero probe is selected on the basis of the “mirror” surface / probe and the proximity of the viewing avatar / camera to it.
    • Thus, if there are 5 mirrors place in a room, only the mirror closest to any given avatar / avatar camera will be used as a hero probe within that avatar’s viewer; the other four will remain “standard” probes, until such time as the avatar / camera moves closer to one of them, at which point it will become the hero probe, and the former hero will revert to a standard probe.
  • The primary use case for this work is mirrors, but it is possible, depending on performance impact, etc., that in the future, one additional hero probe might be allowed per scene, and the use case broadened (e.g. the water reflections).

In Brief

Via the TPVD meeting

  • Simulator updates: two simulator RC are currently with QA:
    • One includes updates to the avatar arrival code (i.e. handling avatars being received into the region via TP) which should help reduce the “viewer freeze” / frame rate drop others in the region can experience.
    • The other includes bug fixes and additional LSL functions.
  • General discussions on:
    • Anecdotal spotting of increased teleport failures, but lacking specifics on location, repro, etc. LL’s gridwide stats on TPs is not reflecting any noticeable uptick in failures. Therefore, those who do encounter them frequently are asked to:
      • Log where / when / how such failure occur.
      • If a pattern emerges (e.g. failures consistently occur when teleporting after doing X, or, say, in the first TP are logging-in, or anything else which suggests a possible underlying pattern), to file a Jira bug report, providing as much of the info they’ve gathered as possible.
    • A similar anecdotal report on people seeing themselves (or others as clouds for extended periods with in increased frequency. Again, where this is seen to happen consistently, a bug report is requested.
    • The official viewer CHUI + lack of chat bar (which also leans into what appears to be a lack of awareness that the Chat Console is not a “Firestorm feature”, but something generally available to people – although new users may need their attention directed to (and how to open chat from it), as the fade-out can case thigs to be missed and the click-to-open chat is not obvious.
    • On options available if TPVs that are not available in the official viewer (or possibly, with some, just not exposed through the UI), but which possibly should be.
    • Please refer to the TPVD meeting video below for further details on the above discussions.

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.

July 2023 SL Web User Group (WUG) meeting summary

The Web User Group meeting venue, Denby

The following notes cover the key points from the Web User Group (WUG) meeting, held on Wednesday, July 5th, 2023.

WUG meetings:

  • Are held in-world, generally on the first Wednesday of the month – see the SL public calendar.
  • Cover Second Life front-end web properties (Marketplace, secondlife.com, the sign-up pages, the Lab’s corporate pages, etc.).
  • They are not intended for the discussion of Governance issues, land fees / issues, content creation & tools, viewer or simulator development / projects. Please refer to the SL calendar for information on available meetings for these topics.

A video of the meeting, courtesy of Pantera, can be found embedded at the end of this article (my thanks to her as always!), and subject timestamps to the relevant points in the video are provided. Again, the following is a summary of key topics / discussions, not a full transcript of everything mentioned.

This was not the “usual” for of meeting – little was said by way of web updates, etc., which have occurred since the last meeting and no updates on upcoming projects.

In Brief

  • A general discussion on how Flickr is used in relation to the Marketplace: creators using it to promote new products and / or encourage interest in their brands / as an alternative to using in-world Groups, etc., through photo competitions, giveaways, etc; fashion bloggers using it as a means to micro-blog about clothing, hair accessories, etc .; users being able to flow merchants and see images / videos of new releases directly on their Flickr feed, etc.
    • Not sure on the purpose of the question (from the Lab), and no-one asked in the meeting.
  • A request for people who would like to see ONE thing WRT SL web properties and services (preferably). Responses include:
    • Allowing multiple versions of items (e.g. different colours) within a single listing (as has been LOOONNG promised with the Marketplace Styles function, but has yet to actually surface); or to have different versions of an item to be individually listed, but have buttons  within their listings so that users can easily toggle between the, a-la Amazon (e.g. so if an item is offered in say, single, twin, triple and quadruple sets, the various sets (and their prices) appear as a button on one another’s listing page so that users can swap back and forth between them).
    • The ability to remove certain stores / items from Search results (e.g. search for “cars” and have an option to select “don’t show me products from this creator again”, and having further results from that creator removed / excluded from search results).
    • The ability to click on reviewers’ names and see a full list of all their reviews (allowing for better judgement of their bias, etc.).
    • The ability to contact sellers directly through the MP.
    • Having fields which state when an item was listed / last updated on the MP.
  • How does Search order results? It varies, but as a rule of thumb:
    • “First time” searches & general searches from the MP home page, should show results by relevance.
    • “First time” searches of stores should list in terms of newest first.
    • If an option to display search results has been previously selected from the drop-down, that is generally the option use to order the results of further searches (until changed).
  • A lot of discussion on the pros and cons of “brand tagging” listings + identifying folders in Inventory.
  • Very much a meeting where it is easiest to watch the video (enable closed caption if required).

Next Meeting

  • Wednesday, August 2nd, 2023.

2023 week #26: SL CCUG meeting summary

Pemberley – May 2023, 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, June 15th, 2023 at 13:00 SLT. 

These meetings are:

  • For discussion of work related to content creation in Second Life, including current work, upcoming work, and requests or comments from the community, together with viewer development work.
  • Usually chaired by Vir Linden, and dates and times can be obtained from the SL Public Calendar.
  • Conducted in mixed voice and text chat. Participants can use either when making comments  or ask or respond to comments, but note that you will need Voice to be enabled to hear responses and comments from the Linden reps and other using it. If you have issues with hearing or following the voice discussions, please inform the Lindens at the meeting.

The following is a summary of the key topics discussed in the meeting, and is not intended to be a full transcript of all points raised.

Viewer News

  • Maintenance T RC viewer updated to version 6.6.13.580700 on Wednesday, June 28th.
  • The GLTF viewer updated to version 7.0.0.580717 on Tuesday, June 27th.

The rest of the official viewers currently in the pipeline remain as:

  • Release viewer: Maintenance S RC viewer, version 6.6.12.579987, dated May 11, promoted May 16.
  • Project viewers:

In addition:

  • Maintenance T is likely the next RC viewer remains the next in line for promotion to de facto release status.
  • The Emoji project viewer is liable to see further improvements to the Emoji picker in the UI.

glTF Materials and Reflection Probes

Project Summary

  • To provide support for PBR materials using the core glTF 2.0 specification Section 3.9 and using mikkTSpace tangents, including the ability to have PBR Materials assets which can be applied to surfaces and also traded / sold.
  • There is a general introduction / overview / guide to authoring PBR Materials available via the Second Life Wiki.
  • For a list of tools and libraries that support GLTF, see https://github.khronos.org/glTF-Project-Explorer/
  • Substance Painter is also used as a guiding principal for how PBR materials should look in Second Life.
  • Up to four texture maps are supported for PBR Materials: the base colour (which includes the alpha); normal; metallic / roughness; and emissive, each with independent scaling.
  • Given the additional texture load, work has been put into improving texture handling within the PBR viewer.
  • In the near-term, glTF materials assets are materials scenes that don’t have any nodes / geometry, they only have the materials array, and there is only one material in that array.
  • The overall goal is to provide as much support for the glTF 2.0 specification as possible.
  • To provide support for reflection probes and cubemap reflections.
  • The viewer is available via the Alternate Viewers page.
  • Please also see previous CCUG meeting summaries for further background on this project.

Status

  • The new RC viewer includes the automatic adjustment to make skies “PBR-ified” (so the checkbox in Graphics Preferences to disable automatically apply reflection probe ambience on skies that do not have it set, so they will be set to a default of 1). Probe ambience must now be set to 0 through the sky settings to deactivate HDR rendering (so no dynamic exposure so the sky is not brightened, and objects with PBR materials will appear duller than intended), and tone mapping is turned off.
    • However, there is a recognised bug related to probe ambience (BUG-234060 “[PBR] Simulator Clamping Environment’s Reflection Probe Ambience to 1”, and it is hoped a fix for this will be in the next simulator build – although it may take a while for the build to make its way into a deployment.
  • The-user supplied PBR content created on Aditi is being transferred to the PBR regions on the Main grid in readiness for more widespread viewing / testing.
  • The LDPW will be producing a PBR demonstrator which will be available through the viewer library.
  • The simulator-side support for glTF Materials is due to be expanded with further simulator RC deployments, which will notably include some sandbox environments.
  • However, it should be noted that:
    • Any glTF / PBR materials content created within these environments which is taken and then rezzed in any region that is not Materials-enabled, will become “material-less” in a non-recoverable way, and will need to be recreated.
    • Because of the above point, until the glTF support is fully gird-wide, any attempts to put PBR-enabled goods on the Marketplace will be sanctioned.
  • General bug fixing on both the simulator and the viewer is continuing.

PBR Terrain

Materials applied to Second Life terrains. Credit: Linden Lab
  • Per past meeting notes, Cosmic Linden is prototyping the application of PBR materials on terrain (see this blog post for more).
  • Further work on bug fixing, including correcting an issue with triplanar mapping to the for terrain repeats, particularly on steep elevation changes (so as to avoid the all-too familiar “stretching” seen with textures).
  • Important notes with this work:
    • It is not terrain painting. It is the application of PBR materials – terrain painting is described as “something that’s on the radar” at LL.
    • The work does not include support for displacement maps.
    • The work is currently only viewer-side, with no corresponding server-side support, the idea here being to prototype what might be achieved and testing approaches / results.

Level of Detail (LOD) Discussion

  • Level of detail (LOD) refers to the complexity of a 3D model representation. In short the idea is to reduce the load on the rendering system by reducing the complexity of the 3D object based on various of criteria (e.g. the distance of the object from the viewer / camera) and using various techniques.
  • Second Life uses the approach of Discrete Levels of Detail (DLOD) method – the use of discrete versions of the original with decreased levels of geometric detail to replace the more complex models using an algorithm primarily based on distance. This has both positives and negatives, some rooted in poor modelling practices by some content creators, others are inherent to flaws within SL itself.
  • In looking at glTF and mesh imports in the future,  LL is considering moving towards more automated and better optimised means of creating LODs to try to reduce some of the current issues.
  • One idea under consideration to achieve this is to leverage Simplygon (or see the Wikipedia entry), which although a proprietary tool, is available as a plug-in for a number of 3D modelling towards (including Blender); the idea being the glTF importer consume whatever output is generated by Simplygon at the creator’s end of the workflow (it being noted that “simply” integrating Simplygon into SL isn’t feasible).
    • Such an approach would offer advantages of optimisation whilst leaving the current upload process in place for those wishing to continue to use it, together with the continued ability to manually create LODs.
  • Some concerns over this possible approach raised at the meeting were:
    • It does not address issues of avatar complexity, which is potentially the biggest viewer performance hit – although in fairness, avatar complexity is really an issue requiring its own focus / project.
    • The nature of some of the Simplygon licensing statements (concern about which might be a mix of the genuine and a basic misunderstanding of legal terms used with regards to “how the Internet works”, so to speak; an issue we had back when LL changed some of the terminology within the SL TOS in 2013).
  • While there are other optimisations tools available, given the state of flux with things within the open source environment, and given Simplygon is recognised as an “industry standard”, offering a means to take output from in and bring it into Second Life is currently seen as the best strategy by the Lab, subject to the concerns raised about the licensing requirements.

In Brief

  • There have been reports of Animesh objects changing / becoming stuck in their lowest LOD in various circumstances, including on region crossing (see BUG-233691 “Animesh re-renders at lowest LOD for extended interval after long-range llSetRegionPos” + listed duplicates). This is believed to be a bounding box issue, and a fix is being developed which should hopefully make it into the next update of the Maint T RC viewer.
  • For PBR, the questions was raised about converting older content with the current Blinn-Phong materials to PBR where the base colour map is not available. The recommendation is that the two are kept separate: if the base colour map is not available for conversion, that Blinn-Phong should continue to be used. No attempt on LL’s part will be made to try to combine the two (PBR / Blinn-Phong) through any kind of conversion tools, as the two are currently entirely separate, allowing creators / users to apply PBR to items which may already have Blinn-Phong, and if the results aren’t good, strip the PBR away and immediately revert to the Blinn-Phong materials. Any attempt to allow “blending” between the two approaches will immediately break this.
  • One consideration actively being worked on within the Lab is glTF licenses and Second Life being able to recognise these. Licences tend to be built-in to glTF complaint 3D models, so as the end goal of the glTF project is to effectively be able to take a glTF model from (say) Sketchfab and drop it into SL, this should be done in respect of the object’s licensing (e.g. if it has a Creative Commons Non-Commercial license, it can be imported into SL but not re-sold after the fact or placed on the SL Marketplace).

Next Meeting

  • Thursday, July 6th, 2023.

† 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.

2023 SL SUG meetings week #26 summary

Ethereal City Estate – Ethereal City Noir, May 2023 – blog post

The following notes were taken from the Tuesday,  June 27th Simulator User Group (SUG) meeting. They form a summary of the items discussed and is not intended to be a full transcript. A video of the entire meeting is embedded at the end of the article for those wishing to review the meeting in full – my thanks to Pantera for recording it.

Meeting Overview

  • The Simulator User Group (also referred to by its older name of Server User Group) exists to provide an opportunity for discussion about simulator technology, bugs, and feature ideas.
  • These meetings are conducted (as a rule):
  • They are open to anyone with a concern / interest in the above topics, and form one of a series of regular / semi-regular User Group meetings conducted by Linden Lab.
  • Dates and times of all current meetings can be found on the Second Life Public Calendar, and descriptions of meetings are defined on the SL wiki.

Server Deployments

  • On Tuesday, June 27th, the simulator release 580543 was deployed to the SLS Main channel, placing all of the simhosts across the grid on the same release. This release includes:
    • PATCH method now enabled through LSL HTTP for both send and receive.
    • HEAD method now allowed through llHTTPRequest.
    • Linkset Size has been increased from 54 to 64m to match maximum prim size.
    • llGetAgentInfo can now detect scripted agent status.
    • See this official blog post for more.
  • On Wednesday, June 28th, the PBR Materials simulator code, currently on a limited Main grid deployment (Preflight channel only, I believe), will be updated. All other RC channels will be restarted without any changes to their simulator versions.

Viewer Updates

The Second Life Project Inventory Extensions viewer, version 6.6.13.580656, was issued on June 26th – see my overview for more.

The remaining viewers in the pipeline are:

Changes to How Asset UUIDs are Assigned

Right now when assets ids are assigned it is simply generated. We’re going changing that a bit. We’re going to start trying to de-dupe new assets. So if you were to upload to identical pictures of Kevin Bacon they would both end up with the same asset ID.

– Rider Linden

  • This is a major change to be deployed in an upcoming simulator release.
  • It will apply to textures, notecards, scripts (possibly gestures).
  • UUIDs for rezzed objects will remain unique.
  • The change also will not affect any UUIDs the viewer makes
  • The reason for this change is the Firestorm Bridge – which saves the same LSL script when it is created.
  • Refer to the latter half of the video below for further details on the discussion.

In Brief

  • Teleports:
    • Some are reporting increases in teleport failures, possibly the result of a failure mode wherein the simulator from which an agent (avatar) is departing closes the connection with the receiving simulator before the teleport has completed.
    • BUG-234022 “Teleport just before to change state will prevent the change state to occur” has also been filed, relating to issues with large scripts within worn attachments failing to correctly update on teleport / logging-in.
  • BUG-232037 “Avatar Online / Offline Status Not Correctly Updating” has seen some work put into it (currently with the Lab’s QA team) which many held ease the problem once it reaches a deployment status.
  • A general discussion on scripting issues – please refer to the video for details.

† 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 rooftop of people every week. They are taken from my list of region visits, with a link to the post for those interested.

2023 SL SUG meetings week #25 summary

Natthimmel – Göbekli Tepe. May 2023 – blog post

The following notes were taken from the Tuesday, June 20th Simulator User Group (SUG) meeting. They form a summary of the items discussed and is not intended to be a full transcript. A video of the entire meeting is embedded at the end of the article for those wishing to review the meeting in full – my thanks to Pantera for recording it.

Meeting Overview

  • The Simulator User Group (also referred to by its older name of Server User Group) exists to provide an opportunity for discussion about simulator technology, bugs, and feature ideas.
  • These meetings are conducted (as a rule):
  • They are open to anyone with a concern / interest in the above topics, and form one of a series of regular / semi-regular User Group meetings conducted by Linden Lab.
  • Dates and times of all current meetings can be found on the Second Life Public Calendar, and descriptions of meetings are defined on the SL wiki.

Server Deployments

  • There was no deployment on the SLS Main channel on Tuesday, June 20th. However, the simhosts were restarted.
  • On Wednesday, June 21st, the RC release deployed to the BlueSteel channel will be deployed to the rest of the RC simhosts. This release includes:
    • The “bot detection” update (i.e. AGENT_AUTOMATED constant for llGetAgentInfo() – so only detects if that flag is set, not if an agent is a bot or not.
    • The second part of the LSD rezzing fix + lLinksetDataDeleteFound and llLinksetDataCountFound, among other things.

Viewer Updates

No changes to the crop of official viewers for the start of the week, leaving the available list as:

In Brief

  • This was a solstice party week, so not a lot of technical discussion.
  • Depending on who was speaking, vehicle-based region crossings either appear to have improved for some reason, or at exactly the same.
  • There is a bug with the automated Map refresh / clearing which can result in regions removed from the grid being removed from the Map. Anyone noticing this is asked to raised a support ticket requesting the Map be updated.
  • The Lab is playing with an experimental capability for adding labelling to the Map – some of this was shown by Alexa Linden some time ago, but the experiments at the Lab are continuing, although it is not clear if any of this work will result in anything user-facing, as currently the overlay is effectively a replacement for the actual Map tile, hence why the examples below are on “empty” parts of the the Map.
The latest in LL’s experiments with Map overlays
  • llLinksetDataDeleteFound and llLinksetDataCountFound are awaiting documentation, but are now integrated into the next maintenance simulator.
  • A semi-entertaining discussion on Babylon 5 and Star Trek – who would’ve said Rider Linden is a B5 fan?! All I’ll say is not Zathras – because no-one ever listens to Zathras. Zathras, however, probably did say so. Even if only to Zathras.‡.

† 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 rooftop of people every week. They are taken from my list of region visits, with a link to the post for those interested.

‡ No, I’m not going to explain that further. Watch Babylon 5 and find out. You won’t regret it 🙂 .

2023 week #24: SL CCUG meeting summary

The Last Aokigahara Souls, April 2023 – 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, June 15th, 2023 at 13:00 SLT. 

These meetings are:

  • For discussion of work related to content creation in Second Life, including current work, upcoming work, and requests or comments from the community, together with viewer development work.
  • Usually chaired by Vir Linden, and dates and times can be obtained from the SL Public Calendar.
  • Conducted in mixed voice and text chat. Participants can use either when making comments  or ask or respond to comments, but note that you will need Voice to be enabled to hear responses and comments from the Linden reps and other using it. If you have issues with hearing or following the voice discussions, please inform the Lindens at the meeting.

The following is a summary of the key topics discussed in the meeting, and is not intended to be a full transcript of all points raised.

Viewer News

No official viewer updates up until the meeting, leaving the list as:

In addition:

  • Maintenance T is likely the next RC viewer in line for promotion to de facto release status; however, it currently has an elevated crashed rate compared to the current release viewer, so LL is looking to bring that down before any promotion in made.
  • The Emoji project viewer is liable to see further improvements to the Emoji picker in the UI.
  • All of the back-end work (simulator code and the inventory service) seen as necessary to support Inventory Thumbnails is now thought to be in place, opening the door for a Thumbnails project viewer “Soon™”, which is apparently awaiting QA clearance.
    • Apparently this now provides the option of displaying the contents of an inventory folder either as we’re currently familiar with them (icons and text) or in a “thumbnail view” – I’ll review this once the viewer is available.
    • It’s anticipated that as the feature goes mainstream, creators will include thumbnails with their product offerings, as well as users creating their own thumbnails of items already in their inventory.
  • A further Maintenance RC viewer (Maint U) is in development and could be surfacing “Soon™”.

glTF Materials and Reflection Probes

Project Summary

  • To provide support for PBR materials using the core glTF 2.0 specification Section 3.9 and using mikkTSpace tangents, including the ability to have PBR Materials assets which can be applied to surfaces and also traded / sold.
  • There is a general introduction / overview / guide to authoring PBR Materials available via the Second Life Wiki.
  • Substance Painter is also used as a guiding principal for how PBR materials should look in Second Life.
  • Up to four texture maps are supported for PBR Materials: the base colour (which includes the alpha); normal; metallic / roughness; and emissive, each with independent scaling.
  • Given the additional texture load, work has been put into improving texture handling within the PBR viewer.
  • In the near-term, glTF materials assets are materials scenes that don’t have any nodes / geometry, they only have the materials array, and there is only one material in that array.
  • The overall goal is to provide as much support for the glTF 2.0 specification as possible.
  • To provide support for reflection probes and cubemap reflections.
  • The viewer is available via the Alternate Viewers page.
  • Please also see previous CCUG meeting summaries for further background on this project.

Status

  • There is another viewer RC in the works. This has been delayed whilst a number of bugs were resolved, but it is now with QA and pending their OK, it should be surfacing in the very near future.
  • The water fog density range has been updated in the PBR viewer. It was capable of being set from -10 through to 10, but is now  “almost zero” through to 100, with the higher numbers indicating higher fog density (and lower visibility).
  • Sky settings:
    • As per my notes from the last CCUG, all “legacy” skies which do not have a probe ambience set, will have one automatically applied by the viewer.
    • This has lead to a checkbox being including in the Graphic Preferences to disable the automatic application. However, it is possible / likely the check box will be removed.
    • This will mean the only way to have “legacy” skies render as they did pre-PBR will be to set the probe ambience setting to zero in the sky settings.
    • Setting probe ambience to 0 effectively deactivates HDR rendering and tone mapping etc.
  • The above requirement to set the probe ambience to zero has two further impacts:
    • It will be the only means by which “legacy” materials can be rendered as they did pre-PBR; the viewer “hack” to desaturate and “nudge” the luminance of “legacy” materials to have them render as they did pre-PBR has been removed due to combination of factors, including a noticeable performance hit.
    • The hack that allowed full bright objects to be exempt from dynamic exposure (so they would always stay the same brightness no matter what the exposure) has also had to be removed from the viewer, again as a result of a noticeable performance hit (an extra texture sample for each pixel). So, full bright object will, in future versions of the PBR viewer, be subject to the same exposure rules as everything else in the scene.
      • This means that full bright objects will still appear to be lit by 100% of the light and be unaffected by things like local lights, but the overall dynamic exposure of the scene will also brighten / darken them in keeping with the rest of the scene, and tone mapping will be applied.
      • SL photographers who display their images in-world with full bright are going to need to experiment with using sky settings with tone mapping disabled when taking their shots in order to avoid it being applied twice to images (e.g. once when the snapshot was taken and again when displayed in-world) and having this unduly affect the full bright rendering of the image.
  • Screen Space Reflections (SSR) – (non-SL overview):
    • Glossy support led to performance hits, particularly when there were a lot of alpha objects in the scene being rendered.
    • This has now been mitigated via a number of means; e.g. SSR is not even applied if it exceeds a certain roughness value, nor is it applied to alpha blended objects (the “old fade-out” method is used – that is: the higher the roughness, the weaker the SSR and the greater the reliance on reflection probes).
    • There have also been some general adjustments to SSR to again try to reduce the performance hits, whilst also allowing more distant objects to be reflected off of surfaces – said to be noticeable on water and flat surfaces.
  • The SSR work provoked a reminder that it is important not to abuse the use of alpha surfaces when SSR is used in rendering.
    • For example:
      • If the object is just a single layer users will be looking through to see what lays beyond, than alpha blending “may be the right choice”.
      • However, alphas should not be used to create layered effects (e.g. setting the faces of a surface to transparent for a “window” and then applying a further alpha to give the window a “frosted glass” look, and having the viewer composite them when rendering. Instead, both alphas should be baked down into one material in PhotoShop (or similar) & applied).
    • This sparked a discussion on how general users who dabble in content creation and who may be used to working in certain ways, can be properly educated to understand things like this – which may be known and understood by mainstream content creators, but could easily pass others by, as there is no means within the viewer UI of telling what is “good” or “bad” techniques when banging things together (at least until frame rates disappear through the floor and into the cellar).
    • It was therefore suggested again that documentation on the wiki – “best practices” / a “bible” for PBR Materials creation / use really should accompany the formal release of PBR Materials, and this should be clearly pointed at though blog posts, etc.

PBR Terrain

Materials applied to Second Life terrains. Credit: Linden Lab
  • Per past meeting notes, Cosmic Linden is prototyping the application of PBR materials on terrain (see this blog post for more).
  • The focus currently is on adding triplanar mapping to the for terrain repeats, particularly on steep elevation changes (so as to avoid the all-too familiar “stretching” seen with textures).
  • The above does potentially incur a performance hit, as it is noted as being for “sufficiently capable machines”, so Cosmic has also been working on trying to optimise performance elsewhere in the use of materials on terrain, as well as carrying out some bug fixing.
  • Important notes with this work:
    • It is not terrain painting. It is the application of PBR materials – terrain painting is described as “something that’s on the radar” at LL.
    • The work does not include support for displacement maps.
    • The work is currently only viewer-side, with no corresponding server-side support, the idea here being to prototype what might be achieved and testing approaches / results.

In Brief

  • It was re-iterated that long-term graphics support on the MacOS side will be MoltenVK (with Vulkan the likely route for Windows), with Zink also being looked at.
  • New user retention:
    • It has been suggested that as many in the various SL communities – those running Community Gateways, content creators, etc., – all have a interest in the new-user experience and brining people into SL, that a semi-regular “New User Experience” meeting might be established by LL at which ideas can be more readily discussed, feedback given and communities and creators more directly engaged with LL’s own efforts (e.g. developing an ecosystem of clothing, etc., to support the (still) upcoming new starter avatars. etc.).
    • It was pointed out that one of the best ways to encourage retention is for existing users to be welcoming, polite and supportive of new users (clubs that have scripts auto-ejecting people just because they are only a handful of days old or on the basis that an avatar is not PIOF, for example, aren’t exactly rolling out the welcome mat, for example).
    • The above spun into a general discussion on content, content moderation, and similar.
  • There was a general discussion on Land Impact (LI) and how it is “too high” – although this is highly subjectively, given the diversity of content and its uses in SL (static, animated, Animesh, etc. – how high is “too high”? Is “too high” down to more a lack of understanding of actual rendering + simulator load costs than an objective measurement? etc.). That said, it was acknowledged that more could be done t help “improve” LI in some areas.
  • The above spun into a discussion on physics costs, and how convex hull physics forms are not the most efficient for SL due to the complexity of the tools used to create them, and the ease with which mistakes can be made in creating them, with indications that as the glTF project moves towards support for mesh uploads how physics shapes are used / applied is likely to be be revised.

Next Meeting

  • Thursday, June 29th, 2023.

† 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.