Tag: Simulator User Group 2026

The following notes were taken from the Tuesday, July 14th, 2026 Simulator User Group (SUG) off-week meeting (the “SUG Leviathan Hour”). These notes form a summary of the items discussed, and are not intended to be a full transcript. They were taken from my chat log of the meeting, and Pantera’s video is embedded at the end of this article – my thanks to her, as always, for recording and providing 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 is held every other Tuesday at 12:00 noon, SLT (holidays, etc., allowing), per the Second Life Public Calendar.
• The “SUG Leviathan Hour” meetings are held on the Tuesdays which do not have a formal SUG meeting, and are chaired by Leviathan Linden. They are more brainstorming / general discussion sessions.
• Meetings are held in text in-world, at this location.

Simulator Update

• As recorded in my notes from the the previous Simulator User Group, there has been a bug which has been causing some regions to fail to grant capabilities.
• Rider Linden has been investigating the issue, and a hot fix should have been / will be deployed during the July 14th SLS Main channel restarts and the restarts of the RC channels on July 15th.

Game_Control

• Whilst not directly linked to Lua, Leviathan hopes to get his work on game_control complete and into the Lua editor viewer so it can be shipped with the Linux viewer support.
• It has been suggested that PromptFont could be used for the game_control preferences UI, and Leviathan is investigating this.
• He will also be providing some viewer-side actions that can be mapped to, and triggered by, pressing buttons on the game controller (e.g. fly, run, toggle Voice on/off) in addition to the existing ability to move the avatar around (walk, crouch-walk, jump, strafe).
• Another area of work he is investigating is to add a limited interaction capability so avatars can walk up to in-world, unseated object and transmit an action event to it (such as display any dialogue menu it has associated with it).
• Leviathan has previously mentioned the idea of adding “semantic” meanings to the game-control data, and had been considering adding a new event to provide that info.
  • However, Monty Linden has suggested using a new function call (e.g. “llGetSemanticGameControl()” or similar) which could be used in the regular event to get the same data but resorted according to how the viewer has mapped it.
• Leviathan noted he also needs to add new data to the GameControlInput message.
• These updates led to a further discussion on possibilities for game_control together with possible additional avatar movement option – please refer to the video for more.
• Alongside of game_control, Leviathan has been working on enhancement for the viewer’s flycam capabilities (e.g. for use with a 3D mouse system), such as Roll. More work is required on this, which might see the enhancements ported to game-control.

In Brief

• Leviathan noted he has been working on a fix for an issue he actually caused, in which attachment scripts sometimes cease working correctly according to parcel permissions. He tracked this to his changes in making the simulator process idle scripts faster.
• Lua:
  • Following an internal meeting, it appears there is a “hopeful tentative plan” to release Lua in the “O” simulator update.
  • If time frames stand, this could be sometime in late August or September, given that the next simulator release will be Mango, which will be followed by Nectarine, which is targeting late July or August.
  • This would see the Lua editor viewer (with resumed official support for Linux) released around the same time, if not a little earlier.
• Work on this has not as yet been merged into the simulator development code.
  • Leviathan believes the work is almost done, he just needs consensus for the rest of the team that the fix as he’s implemented it is the right thing to do.
  • Once consensus has been reached, the fix will likely be merged into the simulator development code for a future release.
• It has been reported that there is an issue with events being dropped causing scripts to stop working as intended.
  • One report is that  scripted object stop working correctly when they change owner change owner, or message_linked or linksetdataRead randomly stop working.
  • The issue of scripts dropping is known to LL and Monty Linden is apparently investigating it.
• A report has been made about the new dual-queue UDP messages processing code (currently in viewer-development but not released) in the viewer in that it causes out-of-order messages processing.
  • In particular, the first ObjectUpdate message creating an avatar can be processed too late and after the AvatarAppearance message to rez that avatar: since the avatar object is not yet created (not in object list), the AvatarAppearance is ignored and the avatar does not rez.
  • This may be due to there being assumptions in the dual queue design (both server and viewer side), which could be inappropriate, on the order in which some messages must be sent and processed for things to work properly.
  • Leviathan has indicated this will be looked into.
• The above prompted Leviathan to note that he has a follow-up project to his UDP work and related to viewer networking he still hopes to get to.
  • This will be to tighten up the back-pressure info from viewer to server when it starts to get overloaded by network traffic, the problem being that when the viewer gets into this state, it will inform the server, but the process to send the messages takes too long and the viewer might only inform the primary simulator to which it is connected, not all the simulators it is currently talking to.
  • This led to a brief discussion on bandwidth throttling and use of an ACK UDP message to inform the server that its UDP queue is getting full, reducing the volume of messages until the flag is cleared by the viewer.
  • This was seen by Leviathan as a good idea.
  • See the last 15 minutes for the video for more on this.

Date of Next Meetings

• Formal SUG meeting: Tuesday, July 21, 2026.
• Leviathan Linden: Tuesday, July 28, 2026.

The following notes were taken from the Tuesday, February 10th, 2026 Simulator User Group (SUG) off-week meeting (the “SUG Leviathan Hour”). These notes form a summary of the items discussed, and are not intended to be a full transcript. They were taken from my chat log of the meeting, and Pantera’s video is embedded at the end of this article – my thanks to her, as always, for recording and providing 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 is held every other Tuesday at 12:00 noon, SLT (holidays, etc., allowing), per the Second Life Public Calendar.
• The “SUG Leviathan Hour” meetings are held on the Tuesdays which do not have a formal SUG meeting, and are chaired by Leviathan Linden. They are more brainstorming / general discussion sessions.
• Meetings are held in text in-world, at this location.

Mesh Face Count Mismatch Bug

• This is a long-term bug whereby some mesh objects fail to accept a texture change on some faces. The texture change shows up on the viewer, but if you take to inventory or relog the texture change vanishes.
• The problem appears to require changes on both on the simulator side and on the viewer.
• Leviathan describes the bug a a form of protocol bug introduced by an old asset-upload-pipeline bug, which he believes has been complicated by a viewer-side bug.
• In short:
  • LL pack texture data using a variable-length scheme, depending on whether all faces are the same or there are differences, but the actual number of faces is not encoded; instead the simulator has been relying the number of faces being implicit to the “VolumeParams” of a prim (this approach pre-dating mesh).
  • LL then introduced meshes with up to 8 texture faces.
  • This, combined with a potential bug in the asset upload pipeline which caused the number of faces in the asset to be wrong, caused errors on the server side of things.
  • A fix for the upload problem was implemented, but the the issue persists for mesh objects uploaded prior to any fix for uploads being applied.
• Leviathan has a fix for the simulator issue(essentially a means to encode the number of faces into the legacy texture encoding without breaking protocol and without eating many bytes).
• However, in testing it, he found a viewer-side issue in loading and updating / recording mesh face textures data. He’s still working on this issue, but believes the viewer and server will have to have an updated protocol interpretation so they can communicate how many faces they think there are in an object. the data will live in the new object created by making any changes to a rezzed item.
• He noted that such a fix might also correct the issue of LSL not seeing the right number of faces.
• This discussion also involved some confusion over sculpties and their  total number of faces, and the actual total number of faces (8 or 9 – it’s 8 hard-coded on the simulator).

In Brief

• Leviathan has a fix for the problem whereby when sometimes rezzing an object on a mesh surface will fail and supply an incorrect or misleading message (e.g. not having parcel rez rights or something). See: FIRE-15429 and Beq Janus’ blog Coming to Firestorm soon… A couple of new features for builders and non-builders alike. It is currently in a Pull Request.
• There are no updates on the status of the game_control work,  and the pre-release of the game-control viewer remains unchanged.
  • Moving this project forward is dependent on the progress of the new SL Linux viewer build.
  • The next steps are to make some UI adjustments and identify any further changes required to get the code through QA for release.
  • As a reminder, game_control provides some keyboard mapping options from the existing avatar control actions:
    move forward, strafe, turn, jump, fly, and (maybe) crouch. It doesn’t currently support “all the keys” input.
  • The reason for game_control is to provide LSL scripts access to game controller input. But how the controller interacts with avatar-control, fly-cam, and keyboard mapping complicated things.
  • There was talk during the early days of the project the game_control could be made to handle MIDI inputs; however this is currently not supported.
  • This led to an extended discussion on key mapping options.
• Leviathan expressed an interest in turning to support the current drivers for the Connexion 3D Mouse devices (e.g. SpaceNavigator, etc.), given the current working driver for SpaceNavigator is badly out-of-date, and more recent versions. However, this is an interest, not a commitment to actually do so.

Date of Next Meetings

• Formal SUG meeting: Tuesday, February 17th, 2026.
• Leviathan Linden: Tuesday, February 24th, 2026.

† 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.

The following notes were taken from the Tuesday, January 2th, 2026 Simulator User Group (SUG) off-week meeting (the “SUG Leviathan Hour”). These notes form a summary of the items discussed, and are not intended to be a full transcript. They were taken from my chat log of the meeting, and Pantera’s video is embedded at the end of this article – my thanks to her, as always, for recording and providing 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 is held every other Tuesday at 12:00 noon, SLT (holidays, etc., allowing), per the Second Life Public Calendar.
• The “SUG Leviathan Hour” meetings are held on the Tuesdays which do not have a formal SUG meeting, and are chaired by Leviathan Linden. They are more brainstorming / general discussion sessions.
• Meetings are held in text in-world, at this location.

Simulator Deployments

• There were no planned deployments for the SLS Main Channel.
• Wednesday, January 28th might see the next simulator update 2026.01 (Kiwi) to one or more simulator RC channels. However, this is an assumption given the status of the release last week, and no confirmation was given at this meeting.

Game Control Update

• Leviathan Linden has cut a pre-release of the new game-control viewer, thanks to work by Rye of the Alchemy Viewer.
• If anyone tests on Linux or MacOS, Leviathan would love to have direct feedback on success/failure, either via the SUG meetings or via IM in-world.
  • In this he noted that “MacOS does some silly proprietary checks and only supports a small set of officially sanctioned controllers” and LL are limited to whatever Apple support, as otherwise the viewer doesn’t even see see hardware detection events ton Mac OS.
• He also noted that one feature of game-control is you can allow normal avatar control inputs (either from keyboard or the UI widgets) to be interpreted as game-control events that get sent to the server. But – that mode doesn’t provide access to all the possible buttons that a game controller has: just a few of the buttons, because the game-control feature is a work in progress (WIP) and he hasn’t as yet worked out how best to map everything.

Game_Control Resources

• Game control – Second Life Wiki.

SLua Mini-Update

• General appreciation for the work Harold Linden has put into the project, and requests at LL keep him on for the future – although he has indicated he is happy working as a contractor.
• No news on when the latest simulator-side updates to SLua will see the light of day, but they are not in the upcoming 2026.01 (“Kiwi”) release. They Might make the cut for the follow-on 202602 (“Loganberry”) update.
• The SLua beta viewer is progressing, and will progress to release status in due course.

SLua Resources

• The nine beta test regions are centred on SLua Beta Void (mind the water!).
• Official blog post on Slua.
• Official scripting portal (this is a work in progress and open to contributions – Github for the latter here).
• The Second Life official Discord server / channels.
•  Suzanna’s SLua Guide (Suzanna  Linn).
• Official VScode plugin notes:
  • It is not yet available on the VScode marketplace.
  • Issues and PRs for code submissions can be made here, and the plugin downloaded.
• VSCode plugin + documentation (Wolfgang Senizen – likely be discontinued and contributions shifted to support the official documentation).

In Brief

• Leviathan gave insight into some of his work remit, and those of other members of the simulator engineering team:
  •  Some of his work is visible to residents, but he also work on internal problems: things that are causing headaches for other developers, the support team, etc.
  • Currently, he working on an issue whereby simulator states (simstates) sometimes fail to save. These appear to be related to LL’s use of a new compression scheme for simstates: zstd. This should offer faster compression/decompression and smaller packages. However, it is reporting failures every once in a while. These, Leviathan believes, appear to occur during simulator rolls. He’s still investigating this.
  • Like other members of the simulator engineering team, he is on pager duty for the week. This occurs once every four weeks, and when on pager duty, the team member is typically working on maintenance issues: bugs and such.
• In addition, Leviathan is continuing to investigate / fact-find about the issue whereby when sometimes rezzing an object on a mesh surface will fail and supply an incorrect or misleading message (e.g. not having parcel rez rights or something).
  • Firestorm has a bug post on this – FIRE-15429.
  • Beq Janus also provided a blog post offering a workaround for the issue  see  Why can’t I rez on my mesh table/floor/bed in Coming to Firestorm soon… A couple of new features for builders and non-builders alike.
  • Leviathan suspects the problem has something to do with a failure of the viewer to supply info the server needs, so Leviathan is attempting to try to learn more and find out where it needs to be fixed.
• No work has been started on addressing the wrong-number-of-faces-on-old-mesh-uploads problem yet. However, Leviathan hopes that if he can find time to start looking at this again.
• The search for a new Senior Vice President of Engineering is on-going, and the Lab is “see great candidates”.
• There is a reported workaround for avatars becoming stuck on a region crossings when riding a vehicle:
  • It appears possible to escape from the broken state after a failed region crossing by deleting the sit target, forcing the simulator to recompute what’s sitting on what, and seems to unjam left-behind avatars. If this works, they should be able to walk to the vehicle and re-sit (or RLV potentially used for a re-sit, if available.
  • The workaround is described as “a horrible hack”, but appears to be the best temporary “solution”.
  • Leviathan indicated he will look at it as well.
• A general discussion on the missing SIT_FLAG_INVISIBLE, which also included llSetLinkSitFlags, a working SETMASS() flag – and its workaround and avatar bounding boxes. Please refer to the video for details.
  • The request for a working llSetMass() script method was being requested by some race bicycle creators who wanted to eliminate some variance in vehicle performance.
  • The above rolled into more general discussions and WIBNIs (“wouldn’t it be nice ifs”).
• General discussions on the discrepancy between avatar height and prim height as reported on most viewers and avatar movement (e.g. introducing mousewalking to the official viewer) – again, please refer to the video.
• From comments passed at the end of the meeting, it would appear that the work on implementing RLVa into the official viewer, initiated by Kitty Barnett and Vir Linden (prior to his departure from the Lab) may have been stalled.
• It was suggested that LL carry out a limited survey of TPV users and request then list their top X TPV features that prevent them from using the official viewer. These could then be collated in terms of common requests and used as an initial starting point for possible prioritisation  / integration.
  • Exactly how a good cross-section of TPV users could be found was an open debate.
  • Managing such a task might be problem for LL, as it would require input from all of the core engineering teams to offer their input – deflecting many of them (approx 45 LL employees) for core activities.
  • Contextual note: “approx 45” does not mean that this is the total number of developers work on SL – the Lab utilises contractors on and individual and company (ProductEngine) contractors, plus a lot of general operation on the server-side are now handled through AWS.

Date of Next Meetings

• Formal SUG meeting: Tuesday, February 3rd, 2026.
• Leviathan Linden: Tuesday, February 10th, 2026.

† 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.