Category: SL User Group Meetings

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 31st, 2023.

• 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 viewer development work.
• As a rule, these 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 the location for the meetings.
  • Open to all with an interest in content creation.
• The notes herein are drawn from a mix of my own chat log and audio recording of the meeting, and are not intended to be a full transcript.

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.
• The overall goal for glTF as a whole is to provide as much support for the glTF 2.0 specification as possible.
• 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.
• 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 viewer is available via the Alternate Viewers page.

Further Resources

• SL Wiki: introduction / overview / guide to authoring PBR Materials.
• List of tools and libraries supporting glTF: https://github.khronos.org/glTF-Project-Explorer/ – note that Substance Painter is also used as a guiding principal for how PBR materials should look in Second Life.
• Second Life University: How to Create PBR Materials.
• PBR / glTF release candidate viewers can be downloaded from the SL Alternate Viewers page.
• Content test regions are available at: Rumpus Room, Rumpus Room 2, Rumpus Room 3, Rumpus Room 4, Rumpus Room 5.
• Also see previous CCUG meeting summaries for further background on this project.

General Status

• Cosmic Linden has been working on some permissions updates to make permissions meaningful when being addressed via LSL. This means that is a materials surface in set to No Modify, a script will not be able to change its tint, for example.
  • Support for this is currently on the glTF / PBR servers on Aditi, where it is being tested (same region names as above, just on Aditi).
  • Changes to reflect these updates will also be made to the viewer so things like the build floater correctly reflect the permissions status.
• Runitai Linden is continuing to work on the communications bloat issue. This will utilise a new message type – GenericStreamingMessage. This will both make messages passing between the simulator and viewer more compact and also less frequent in order to reduce the load.
• To help improve people’s awareness / avoid confusion with the updated Build floater, a new pop-up is being implemented that will be displayed and give information on the change when the floater is first opened and used with a PBR material, complete with a link to the PBR wiki page.

Mirrors

• Mirrors are a part of the glTF / PBR materials project, but something of a separate tranche of work.
• The idea is provide the means to have via high resolution reflections (i.e. mirrors) within a scene.
• Initially only one active mirror surface per scene will be active for any viewer.
• The process will use the PBR reflection probes mechanism, combined with a automated “Hero Probe” mechanism which with generate high resolution (512×512) “reflections” for the mirror.
• The system will operate on the basis of avatar / camera proximity to a mirror surface triggering the closest reflection probe to become a “Hero Probe” for that avatar / camera. This means that if there are multiple mirrors placed within an environment, only the one closest to a given avatar / camera will be active and display the “reflections” generated by the reflection probe.
• Depending on testing and performance, the number of mirrors might be expanded to two – one for mirror surfaces and one for Linden Water to generate high resolution water reflections where appropriate.

Summary

• Geenz Linden hopes to start working on a version of the PBR viewer which supports mirrors very shortly.
• The final data model for mirrors will not be available on the server end in time for the initial version of a Mirrors viewer, but will be coming later, as it is dependent on dialling-in the parameters required for the mirrors functionality based on testing.
• Overall, the approach now taken means that mirrors will now not just be limited to planar (flat) surfaces.

Lighting / Ambient Lighting

• Concerns continue to be raised over colour saturation / ambient colour / light within the PBR viewer within non-PBR regions. People appear to be reporting particular issues with over-saturation and with black surfaces (particularly clothing) looking “flat” or minus any clear definition.
• It was pointed out that some of the issue may well be down to a combination of running the PBR viewer within regions that do not have the proper PBR environment adjustments, thus leading  – to some degree at least – to tone mapping being overly biased for darker colours + the adjustments made within the PBR viewer to compensate for the lack of reflection probes in non-PBR regions still requiring further tweaking + the PBR viewer generally not rendering the excess ambient light common to existing ambient lighting in non-PBR regions.
• A lot of this is known to be an issue, and something Runitai Linden has been looking to address, as per my pervious CCUG summaries such as this one.

In Brief

• Rider Linden noted the following updates will be available in the near future via simulator RC releases:
  • “Dog Days” update, due to go to one or more simulator RC channels during week #36 (commencing Monday, September 4th):
    • The unbinding of the Experience KVP database read / write functions from land (users will still require an Experience to access the KVP database).
    • A scripted ability to set CLICK_ACTION_IGNORE, allowing an object to be clicked-through to reach an object behind it – a flag supporting this is included in the current release viewer.
  • The still in development “Fall Colours” update, which will include:
    • llIsFriend – essentially “Is the avatar touching this object a friend of the object’s owner?”, and then act accordingly.
    • llGetInventoyDesc(ription) – a function to return a list of the contents within an rezzed object.
• User Animats has been experimenting with a new open-source convex hull algorithm for making physics models, which he describes as probably “not suitable” for the SL mesh uploader, but which “might be useful” when working in Blender. There is a forum thread on this line of investigation got those interested.
• A suggestion was made that as LL gather stats on the hardware users are employing to access SL, that some measure of this data is made public-facing so that creators might have a better idea of the “typical” hardware environment they need to consider, rather than assuming everyone is either running high-end or low-end systems.
  • This was put in terms of something like a list of the 10 or so most commonly used CPU / GPUs (either individually or in combination); most common RAM amounts used (8GB, 16GB, etc.), with the information made available via a web page or similar.
  • It was pointed out that some of the information might be difficult to put together as it might not be possible to accurately extrapolate or consolidate in a meaningful way.
  • However, Vir Linden thought the idea is worth poking at to see what, if anything might be done towards achieving it.
• An animated discussion on the permissions system and No Mod objects including:
  • Why people use No Mod (such as the mistaken belief that it “prevents copybotting” + the misunderstanding users might have that while a scripted item may way have No Mod scripts, the item itself can still be modified, etc).
  • A idea for the “reset to defaults” override button for Modify object so that if a user royally messes up an object, they can click the button and restore the original look / texturing, etc., of the object (potentially very hand for Mod / No Copy objects).
  • The addition of a new attribute “Demo” which can be used to both lock an object into No Mod and add some form of “demo” indicator to it for when the user is wearing / examining it.
  • The problem with any changes with the permissions system is that it is a) already extremely complicated in its implementation; b) would require considerable care; c) is liable to be a lengthy, far-reaching project. As such, there may not be the appetite within LL to take on such work.

Next Meeting

• 13:00 SLT, Thursday, September 7th, 2023, at the Hippotropolis Campsite.

† 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.

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 17th, 2023. 

• 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 viewer development work.
• As a rule, these 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.

Additional note: this meeting suffered several drop-outs (for whatever reason) plus my own Internet connection also went out; as such this is not a complete reflection of the meeting and all topics.

Viewer Status

• Release viewer version 6.6.13.580918, formerly the Maintenance T RC viewer, July 14.
• Release channel cohorts (please see my notes on manually installing RC viewer versions if you wish to install any release candidate(s) yourself).
  • Maintenance V(ersatility) RC viewer, version 6.6.14.581315, August 15.
  • Inventory Extensions RC viewer updated to version 6.6.14.581357, August 14.
  • glTF / PBR Materials viewer, version 7.0.0.581126, July 26.
  • Maintenance U(pbeat) RC viewer, version, 6.6.14.581101 July 21.
• Project viewers:
  • Emoji project viewer, version 6.6.13.580279, May 30.
  • Puppetry project viewer, version 6.6.12.579958, May 11.

General Viewer Notes

• There are a couple of issues with the Inventory Extensions RC viewer which need to be addressed before this progresses to being ready for promotion to release status.
• The internal discussions on font changes in the Emoji viewer (see my last CCUG / TPV meeting summary) will likely be split into a separate project, allowing the Emoji viewer to progress forward as it is.

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.
• The overall goal is to provide as much support for the glTF 2.0 specification as possible.
• 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.
• 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 viewer is available via the Alternate Viewers page.

Further Resources

• SL Wiki: introduction / overview / guide to authoring PBR Materials.
• List of tools and libraries supporting glTF: https://github.khronos.org/glTF-Project-Explorer/ – note that Substance Painter is also used as a guiding principal for how PBR materials should look in Second Life.
• Second Life University: How to Create PBR Materials.
• PBR / glTF release candidate viewers can be downloaded from the SL Alternate Viewers page.
• Content test regions are available at: Rumpus Room, Rumpus Room 2, Rumpus Room 3, Rumpus Room 4, Rumpus Room 5.
• Also see previous CCUG meeting summaries for further background on this project.

General Status

• The communications bloat driven by multiple script-driven glTF materials updates generating multiple connections between the viewer and the simulator (thus impacting performance) continues to be addressed. The outcome of this work is liable to result in protocol changes as and when the work is complete.
• A number of permission-related fixes have been implemented.

Lighting / Ambient Lighting

• The issue over the rendering changes the glTF project will bring to Second Life. It has been well-established that the PBR system removes the forward render pipe (aka “non-Advanced Lighting Model (ALM)”) from the viewer’s renderer.
• Equally, over the last several meetings (and as noted in my CCUG summaries covering PBR) there has been discussion on the fact that PBR utilises HDR + tone mapping with rendering  / lighting. This is a significant change to Second Life, particularly when it comes to the amount of rendered ambient light (until now SL has rendered a lot of additional ambient light), resulting in two related issues:
  • Because it is intended to mimic real-world ambient lighting, environments rendered on the PBR viewer with HDR + tone mapping enabled can look a lot darker than when viewed with a non-PBR viewer, and baked lighting really does not work (and can end up looking very bad) – scripted / direct lighting is required – something for which many store owners and users in general might not be prepared.
  • While disabling the ambient HDR rendering is possible within the PBR viewer (potentially eliminating the above issues), it conversely results in any PBR content within the scene looking “bad” or “broken”, risking content creators trying to find workarounds to the glTF specification in order to make their content “look good” under either lighting condition – something they absolutely should not do.
• Discussions are still on-going at the Lab on how best to handle this conflict between PBR and non-PBR rendering as the latter is deployed and gradually gains broader use. As a part of this, it has been recognised that one of the most direct means to alert users is via communication.
• To this end, a form of “best practices” and guidelines for PBR are being developed with the intention to make them available to users in advance of PBR being fully deployed / released. Expect to (hopefully) hear more about this via future CCUG meetings.

Mirrors

• Geenz Linden is currently refactoring the Hero probes which will be automatically selected for generating higher resolution reflections based on an avatar’s proximity to a planar mirror surface (and initially limited to 1 (or possibly 2 per scene  – the second being for Linden Water reflections, but this has yet to be confirmed).
•  This work will see the Hero probes treated as their own class of reflection probes with their own filtering, etc., to avoid conflicts (debugging, etc.) with the “general” reflection matte manger. This will also better support the higher resolution of the Hero probes and possibly allow for additional Hero probes to be supported within the viewer in the future.

Building Tools

• PBR will see a significant change to the Edit / Build floater as the project becomes more widely deployed, and this has started internal discussions at LL about the state of the in-world build tools, and what might be done to improve them for general use. Ideas put forward at the meeting included:
  • More flexible means of cutting holes in prims (e.g. offset from the Z axis of the prim), such as through the introduction of a Boolean support.
  • Making text entry within the floater consistent (e.g. clicking on some fields, the existing content is highlighted for over-writing, in others it isn’t).
  • Inclusion of a prim alignments capability (as found in some TPVs) as a default tool + making the alignment more flexible that just to the sides / edges of the bounding boxes of the objects.
  • A broader range of primitive shapes (e.g. simple step units) and improved tools for torturing prims to produce custom shapes.
  • Better exposure of some of the build options on the official viewer (e.g. making the Local Textures option a radio button option in the Texture tab, rather than hidden in a drop-down) to make them more visible.
  • Also making it clearer that an object includes Local Textures, such as via a pop-up, to remind the creator to apply an actual texture to the affected face(s).
  • Better tools  / support for making clothing.
  • Better UDIM support for UV maps.
• These idea will be fed back into discussions at LL.

Senra Avatars

[Note: this section is abbreviated as I lost my Internet connection for some 14 minutes of the meeting & this was followed by the meeting being disrupted a further 2 times.]

• Further discussion over the continued confusion / concern over the Senra avatar system (outside of the ongoing disquiet over the licensing agreement), including:
  • Frustration / confusion over the amount of conflicting information being offered by Linden Lab – e.g. the dev kit application form states applicants “must” own a store but Patch Linden has stated in a forum post that owning a store “is not” a requirement.
  • Negativity on the use of an application requirement at all:
    • Some see it as presenting an unnecessary barrier for some (e.g. users who just want to create Senra-related items for their personal, rather than commercial, use).
    • Concerns over privacy / security with the devkit application form being outside of SL (where it is subject to potential abuse) rather than – as with the Mesh Upload Status form  – being included within the Secondlife.com dashboard,  where it would be both secure and firmly linked to an account.
  • Further questioning as to why AvaStar has been determined to be a core requirement for the devkit, rather than simply relying on Blender.
• More general frustration was voiced at the idea that the “Senra team” only appear to be willing to engage through the forum threads on the topic, and then only in what is perceived as being a narrow focus of engagement, with no-one appearing willing to attend the CCUG meeting – which given Linden Lab want creators to produce content for Senra would seem to be a pretty good place for them to actively address feedback in real time, at least in lieu of any Senra-focused meeting(s).

In Brief

• While they are not in anyway directly connected or related, Cosmic Linden noted that her work on enabling PDR materials as terrain textures in the viewer is being used as a testbed for possible approaches to enabling PBR with avatar Bakes on Mesh – although the latter is not currently an active project.

Next Meeting

• 13:00 SLT, Thursday, August 31st, 2023, at the Hippotropolis Campsite.

† 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.