September 2025 SL Mobile UG meeting summary

The following notes were taken from the Thursday, September 25th 2025 Monthly Mobile User Group (MMUG) meeting. These notes should not be taken as a full transcript of the meeting, which was largely held in Voice, but rather a summary of the key topics discussed. The meeting was recorded by Pantera, and her video is embedded at the end of this summary – my thanks, as always to her in providing it.

Table of Contents Meeting Purpose Resources Current Releases Forthcoming Updates Avatar and Character improvements EEP Rendering Transparency Rendering Lighting / Point Lighting General Improvements Q&A Session Date of Next Meeting

Meeting Purpose

• The Mobile User Group provides a platform to share insights on recent mobile updates and upcoming features, and to receive feedback directly from users.
• These meetings are conducted (as a rule):
  • The last Thursday of every month at 12:00 noon SLT.
  • In Voice and text.
  • At Campwich Forest.
• Meetings 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.

Resources

• Second Life Mobile Beta website.
  • SL Mobile on Google Play.
  • SL Mobile on Apple Store.
• Second Life Mobile on the Feedback Portal:
  • Bug reports.
  • Feature requests.

Current Releases

Version: 2025.7.560 (Android) – July 23 / 0.1.557 (iOS) – July 22.

Forthcoming Updates

[Video: 2:50-17:55]

• A new Alpha build is currently available for Android, and is just waiting to be cleared by Apple (if not already available by the time the post is published).
• This alpha is viewed as being “close” to being ready for a beta release “Soon™”, and includes all current work on the Mobile product, several aspects of which are outlined below.

Avatar and Character improvements

• Load times: a “significant” reduction in the amount of memory required to load an avatar, allowing Mobile to both load more avatars in a scene, and do so more reliably.
  • Performance in environments with large numbers of avatars should also now be improved.
  • There are still some shape changes to be completed to allow all avatars to render correctly, but this work is progressing.
• Network connection stability:
  • As reported in the August update, because of its dynamic nature, SL Mobile requires a constants data stream, and so is far more susceptible to signal interruptions / conflicts with other apps for bandwidth use, etc.
  • Work has therefore been put into making the app more robust in how it maintains network connectivity and continues to function through such interruptions, doing all that is required of it.
  • These improvements also feed into the avatar system as well, further helping with the speed and reliability of avatar loading.
• Under-the-hood work: general optimisations such as re-targeting download orders (e.g. increasing the download priority of avatar clothing downloads to again improve avatar downloading and rendering).
  • This under-the-hood work also includes refining code related to the loading and unloading of in-scene objects, so when moving around the world, content should load / unload more effectively, with more content in general loading.

EEP Rendering

• A first pass at implementing EEP environment settings.
• This is a direct port of the sky shaders used in the viewer, so that scenes should render a lot closer to how they appear on the Desktop viewer.
• The work includes all of the lighting data, fog / haze data, etc., as well as the sky shaders.
• Further work is required on lighting due to differences in how the Unity engine and the SL engine respectively handle lighting.

Transparency Rendering

• Due to the need for order-independent transparency, coupled with limitations within the GPUs used on most mobile devices, SL Mobile has been unable to render “true” transparency, and has had to rely on dithering to approximate transparency.
• One means to get around this is to use temporal anti-aliasing, which LL has been waiting on through an update to the version on Unity they use with Mobile.
• The work on this upgrade was recently completed, allowing said temporal anti-aliasing to be utilising within the app, providing better transparency rendering without any loss of performance.
• Until this work is fully dialled-in, there might be some light ghosting visible when panning around transparent surfaces.

Lighting / Point Lighting

• There is a “slight incongruity” between how Unity handles point lighting (lighting placed around a scene) compared to how Second Life handles the same (the Unity rendering path prefers quadratic lights – bright up close, dim at a distance; SL is more medium-bright when close, medium-dark when further away). This resulting in point lighting in Mobile to look different to the same lighting seen in the viewer.
  • To try to address this, the lighting calculations used for such point lights has been tweaked within SL Mobile so that such lights will be rendered more closely to how they are within the viewer.
• As a general note, updates to directional lighting may allow shadows to be re-enabled in the Mobile app, although shadow rendering is expensive, and further work in this area is required.

General Improvements

• Multi-threading for object and content loading has been improved, which see see more effective use of the CPU cores within a mobile device.
• Streaming audio has been completely rebuilt to avoid using a now-deprecated library within the current beta streaming audio build.
• Improvements made to loading the world following a rapid log-out / log back in.
• General improvements and minor adjustments to the UI. Perhaps the most noticeable of these is the temporary return of the sign-out option as a button in the menu (pending further updates down the road which will likely see it return to a drop-down option once again).
• Improvements to how spinning objects and target_omega are handled.

Q&A Session

[Video 18:14-End]

• Switching to another app when using the SL Mobile app and then switching back to SL Mobile can seem to take time.
  • This is partially out of LL’s hands: apps not in current use can be “moved” from active memory to free-space for other apps. Changing focus can also result in the web page used to assist in rendering the UI being suspended.
  • Both of these factors can result in a delay in resuming a session as the focus is returned to SL Mobile.
  • Consideration may be given to adding a pop-up message about possible delays when switching away from SL Mobile to another app, with a possible more in-depth examination as to what might be done to be carried out at some point in the future.
• Inventory access: outfit sub-folder support, etc: Inventory is something being worked on, but the work is such that no major announcements as to what is being done / what to expect could be made at this meeting.
• Message caching (e.g. people can receive messages whilst on SL Mobile, but also still see them when logged in via the Desktop viewer): there has been some movement on this, and work is continuing, although complex. Further updates in due course.
•  Could the current SL networking calls be used with SL Mobile to save tampering with the SL infrastructure?
  • No,  because SL mobile uses different protocols in order to handle:
    • Swapping between the device’s wifi and cellular connections on the fly.
    • Disruptive connections which could otherwise result in high packet loss – something UDP would have difficulty in managing.
  • The protocols used by SL Mobile also reduce the bandwidth the app uses when compared to Desktop (e.g. transmitting the scene state to SL Mobile uses 97% less bandwidth than the viewer).
• Does SL Mobile run better in landscape mode or portrait? There shouldn’t be any difference.

Date of Next Meeting

• 12:00 SLT, Thursday, October 30th, 2025, at Campwich Forest.