Category: SL Tech

The following notes were taken from the Tuesday, September 2nd, 2025 Simulator User Group (SUG) meeting. 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 the video recording by Pantera, embedded at the end of this summary – my thanks to Pantera for 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 are no planned deployment for the week, only restarts.
  • The restarts include upgrading some of the hardware to better classes of machines in the background, which is being carried out in stages on each restart.
  • Monty Linden noted the Main SLS Main channel restart saw an increase in the mix of more modern AWS hosts, but there were some glitches which led to some regions being off-line for a bit longer than expected.
• It is hoped a new simulator update  – Grapejuice – will be ready for deployment to one or more RC channels in week #37.

In Brief

• Rider Linden is working on an official native VSCode plugin for LSL and SLua. This is proceeding smoothly so far, and the hope is to open the repo opened to public viewing as soon as possible.
  • Right now, this is just for communicating compile errors from the viewer to the plugin.
  • However, he is planning on pushing a lot more through it in the future (e.g. DAP when LUA debugging becomes available).
  • He will most likely put in a LSP interface so that it can communicate with Selene for syntax colouring, etc.
  • There is a viewer branch with the initial code (PR: https://github.com/secondlife/viewer/pull/4599).
• Leviathan Linden is working on getting the webRTC voice router to automatically submit crash reports in a similar manner to the viewer.
• Pepper Linden noted that:
  • Working is continuing on turning on the new dynamic packing, noting there has been a “small road bump” due some issues seen with reported region stats. However, it should be turned on for some RC channel regions this week. Things to look for: better performance/less lag, and less restarts.
  • Pepper is currently working on the outfit project for SL Mobile.
• Monty Linden is “thinking about the eventqueueget and other problems” as he re-visits protocol failures again with a view to updating an improving on his previous work in this area.
• User Suzanna (SuzannaLinn) is producing a website with a SLua guide, including examples and a LSL to SLua transpiler.
• A general discussion on SLua event handling, and on state switching (LSL -> SLua) which led to a wider discussion on coding practices and options which ran through the second half of the meeting.

Date of Next Meetings

• Leviathan Linden: Tuesday, September 9th, 2025.
• Formal SUG meeting: Tuesday, September 16th, 2025.

† 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, August 19th, 2025 Simulator User Group (SUG) off-week meeting (which I refer to as 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 the video recording by Pantera, embedded at the end of this summary – my thanks to Pantera for 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

• On Tuesday, August 19th, the simhosts on the SLS Mian channel were restarted without update.
• on either Wednesday, August 20th or Thursday, August 21st, a new simulator update – code-named Grape Juice (Fig Newton having morphed into the network updates noted in my week #32 summary), should be deployed to one or more RC channels.

SLua Update

• A recap of the recent work on SLua, as given by Harold Linden at the week #33 Leviathan Hour “off-week” meeting. In short:
  • Changes to the Luau garbage collector which means that it can run a lot faster now, so scripts have to pause less and run out of memory less.
  • llGetFreeMemory() and llGetUsedMemory() have been fixed “to return something sensible under SLua”.
  • This sparked a conversation on Mono memory usage, with Harold noting that the memory usage presented by ll.GetFreeMemory() in Mono has little relation to how much memory is actually being used; the value given is basically how many “memory fun bucks” a script has left. He noted it is also on his list to get an accurate measurement including JIT cache overhead, etc.
• Limits on memory use have not been settled as yet, but testing indicates that SLua generally uses less memory than Mono under a typical workload, with Harold noting:

I imagine that no matter what we do, memory limits are going to be higher than they were on Mono. Having tiny memory limits has created perverse incentives to just do things like split things into many scripts that communicate over link messages that end up bogging the sim down more than if everything was in one script … I have felt all the multi-script pain, I’m interested in preventing that pain in SLua

• • This sparked a discussion on memory use and limits in general, which ran through the rest of the meeting.
• Harold Linden has also drafted a proposal for event handling and multi-timer support under SLua, which is described as “roughly inspired by Node’s ‘EventEmitter’ stuff, so you can do ‘LLEvents.on(“touch_start”, some_function)’ and such”.
  • Scripters are encouraged to read and comment on it.
  • There was also a conversation on SLua event handlers during the meeting.
• The above also folded into it a discussion of on_error events.
• Signal Linden is working on scoping SLua milestones and shepherding release and projects, together with planning SLua documentation (wiki).

In Brief

• Monty Linden has “up-cycled” the Experience KVP store – that is, implemented a new package with reliable data retention, under the same version number.
• Pepper Linden noted that a new Conductor was rolled out onto Agni last week, which – subject to further adjustments – should improve packing of regions onto simhosts.
• Rider Linden is about to start a “research spike” into creating an official SL plugin for VSCode for better external editing. He was particularly interested in hearing what people would like to see in this.
• User Henri Beauchamp has been investigating the issue with avatar attachments rezzing (e.g. following a TP or after logging-in, particularly in “busy” regions), and noted that it appears that the server sometimes just does not send all avatar attachments.
  • A report on this issue has also been filed (see: Avatar attachments STILL failing to appear in busy regions).
  • Monty Linden noted that he is also tracking a set of attachment failures (symptoms: the TP completes (TeleportFinish received), when the avatar is in a new region but none of the scripted attachments is realized in the target region).
  • Rider Linden indicated that the Canny report has been triaged, and his hope is to fix the underlying issue(s) rather than “cover it with a band aid to hide it”.
• A general discussion on animation improvements, notably linked to script limitations with furniture (e.g. each agent sitting on an item of furniture requiring a dedicated script to handle animations). This in turn followed into a discussion on inverse kinematics (IK).

Date of Next Meetings

• Formal SUG meeting: Tuesday, September 2nd, 2025.
• Leviathan Linden: Tuesday, August 26th, 2025.

† 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.