SL projects updates week 13/1: server, viewer

SL Server Deployments

As always, please refer to the server deployment thread in the forums for the latest news and updates.

There was again no server deployment to the Main (SLS) channel on Tuesday March 25th. Of the three RC channels, there will be no change to either BlueSteel or LeTigre on Wednesday March 26th. However, the Magnum RC will be updated with a new server maintenance project, comprising:

  • Crash mode fix.
  • Fixed a rare case in which certain users were unable to log in (BUG-5130)
  • Fix for a case in which multiple scripts in the same prim calling llTakeControls() with heterogenous ‘accept’ and ‘pass_on’ parameters would not receive a control() event correctly in some cases (BUG-5281)
  • Updated LSL syntax file to use a new schema (fixes STORM-2000)

The LSL syntax file update for STORM-2000 is part of a large project being undertaken by Ima Mechanic with assistance from Oz Linden (see STORM-1831). This work is currently awaiting the release of viewer-side changes, which have been undergoing testing by LL’s QA.

A lightly-attended Simulator UG meeting, Tuesday March 25th
A lightly-attended Simulator UG meeting, Tuesday March 25th

SL Viewer Updates

On Monday March 24th, the FmodEx Hotfix viewer (, release notes here) was updated to the de facto release viewer. The core updates in this viewer comprise:

  • Crash fix (MAINT-3703)
  • Update FmodEx library to 4.44.31
  • Additional work for MAINT-2718 (Linux viewer was using logging version of library)

Group Chat Work

During the Simulator User Group meeting on Tuesday March 25th, I asked Simon Linden about the outcome of the group chat tests run on Thursday March 20th, now that there’s been time to check the logs files. He said, “It didn’t have any surprises, but that was a good result. That test was mostly checking out the new statistics it gathered, which worked fine too.” He also confirmed that testing with a large group (most likely the Firestorm support group) is the next step in proceedings:

It’s been delayed a bit due to some people being out of the office. I’m hoping to do something next week … I think that’s the earliest possible. In the mean time I’m working on another layer in the back-end system that is inefficient, so I’m hoping to finish that up today or tomorrow and roll it in together.

Other Items

Revision to the TPVD Directory

The Third-party Viewer Directory received a change to the section listing viewers that report crash statistics. Whereas previously, viewers in this section had been ranked from best to worst crash rate (% of sessions that end in a crash), as from March 25th, they are now ordered from best to worst disconnect rate (% of sessions that end without the simulator seeing a logout).

Regions Size Trivia

During a discussion on vehicle design and region crossings, Simon Linde made mention of the factor that he once spent time looking at region sizes in SL. This isn’t the first time he’s mentioned this work. The last time he raised it, he went to far as to indicate that were regions ever to be resized, increasing them to 1 km a side rather than 1024 metres a side would be preferable, although this would impact the power of 2 approach taken with building SL. At the Simulator UG meeting, he reiterated this latter point, saying, “unfortunately the 256×256 region space is carved into the SL design all over … from the database to the simuators to the viewer and the messages. Changing that would be huge.”

A second take with machinima and photography

Cinema! Take II
Cinema! Take II

Cinema! Take II, by Mary Wickentower, is an extension of her LEA interim piece, The Wonderful World of Particles, originally located at LEA13. Now a part of the LEA’s Full Sim Art series, it has relocated to LEA6 and shifted focus more towards machinima and photography.

Those who visited The Wonderful World of Particles, will find Cinema! Take II somewhat familiar, as it utilises the same large centre-piece movie theatre and drive-in movie space, complete with interlinking roads and tall palm trees. The observant may even note the greeter welcomes them to former, rather than Cinema! Take II!

Cinema! Take II
Cinema! Take II

However, this isn’t merely a relocation of the interim project. As noted, the focus is very much on machinima and photography. In terms of the former, the movie house, the Empire Movie Palace, is showing Princess Ambrosia’s Sakoku: Chained Country (which includes some adult-oriented themes), and also includes photo exhibition spaces, used to display entries into a number of photohunts and other photography-related activities being held throughout the month of March (the next being on Wednesday March 26, see below for details).

Outside, at the drive-in one can watch a veritable plethora of machinima by artists and film-makers from around the world. You’ll need media enabled for this (top right corner of the viewer). Click on the movie screen itself to start things, and use the media controls displayed above it to focus your camera or watch movies in a browser tab, etc. A complete list of film-makers can be obtained in a dialogue box by clicking the frame of the movie screen. Click on the button corresponding to a name to display a list of their available films. To select a film, again click on the number in the dialogue box corresponding to the film, then click on the screen itself if the film doesn’t start automatically after a few seconds.

Cinema! Take II
Cinema! Take II

I confess that I had some issues with the drive-in when using either Firestorm or the SL viewer. Often a movie would start, but either have no audio, or feature the audio of a preceding video. Stopping and re-starting media from the viewer’s controls (top right of the viewer window) generally resolved this.

Also included in the region are Danya’s Garden by Danya Sadofsky, a place of peace & quiet, the Swing Jim Dinner, which is the setting for sock hops and dances, the Gallery of Art featuring fine SL sculpture and Dr. Petrol’s Gas Station featuring a classic collection of pin-up posters.
Special events have been a part of the installation’s month-long run, and coming up next are a photohunt and a Visionaire Institute of Photography field trip.

Cinema! Take II
Cinema! Take II

The photohunt will take place at 18:00 SLT on Wednesday March 26th. Participants will be given a theme or landmark by the moderator, and will have 60 minutes to take a snapshot that best embodies that theme / landmark, with absolutely no external photo manipulation allowed. Finished entries will displayed in one of the Empire Movie Palace exhibition spaces.
On Thursday March 27th at 15:00 SLT, students from the Visionaire Institute of Photography will visit the region to photograph Cinema! Take II, with their work also displayed in one of the Empire Movie Palace exhibition spaces.

Cinema! Take II is open until the end of March.

On reaching Kimberley, managing communications and solving mysteries

CuriosityIt’s been a quiet time for the last three weeks as far as news from NASA’s Mars Science Laboratory is concerned. There have been a couple of reasons for this.

The primary reason is that the rover is on a slow but steady drive towards its next intended science waypoint while en route to the lower slopes of “Mount Sharp”. At the start of February, that waypoint had been around half a kilometre from the rover. However, concerns over the amount of wear and tear being suffered by the rover’s wheels as a result of traversing very rough terrain meant that Curiosity took a diversion.

While this put the rover on much smoother – comparatively speaking – terrain, it also meant the route to the waypoint had become more circuitous, requiring Curiosity cover around a kilometre in order to reach its intended stopover. In addition, engineers have been periodically checking the amount of damage to the wheel which may be accruing, further slowing daily progress, as well as continuing to test alternative driving methods to further ease the load on the wheels – such as letting the rover drive backwards towards its destination. However, the good news is that in the month since crossing Dingo Gap on February 18th, wear on Curiosity’s wheels has been around one-tenth what had been experienced per month during the months traversing the rougher terrain.

The long drive south. Murray Buttes mark the point at which Curiosity is expected to start the traverse onto the lower slopes of “Mount Sharp”, which forms a natural break in a line of dark sand dunes between the rover and the mound. “Kimberley” marks the next stop on the way (click for full size)

Additional tests using Curiosity’s test bed “twin” on Earth have revealed that the rover could sustain substantially more damage than incurred so far, including breaks in the wheel treads themselves, and still remain operational. However, given the potential duration of the mission – Curiosity’s nuclear “battery” could provide it with an operational life measured in a couple of decades barring other failures – means caution is key at this stage of the mission.

“The wheel damage rate appears to have levelled off, thanks to a combination of route selection and careful driving,” said JPL’s Richard Rainen, mechanical engineering team leader for Curiosity. “We’re optimistic that we’re doing OK now, though we know there will be challenging terrain to cross in the future.”

MRO Computer Glitch

The other break in news, although brief in nature, was caused by an unexpected issue with Curiosity’s primary communications relay between itself and Earth – the Mars Reconnaissance Orbiter (MRO) unexpectedly switched itself into a “safe” operating mode on Sunday March 9th. This immediately brought a cessation in the orbiter’s communications relay function for both Curiosity and Opportunity on the surface of the planet, although it did not put either rover entirely out of communications with Earth.

An artist's impression of the Mars Reconnaissance Orbiter orbiting the planet
An artist’s impression of the Mars Reconnaissance Orbiter orbiting the planet

While MRO forms the primary means of communications between the surface of Mars and mission control at NASA’s Jet Propulsion Laboratory facility at the California Institute of Technology, the rovers on Mars can also use NASA’s Mars Odyssey as a relay – and, should it be required, Europe’s Mars Express. However, Mars Odyssey, which has been operating around Mars for almost twelve and a half years, has much lower bandwidth and data transmission rates compared to MRO, which reduces the amount of information which can be relayed to Earth at any given time.

MRO’s issue first became apparent on March 9th, when the orbiter performed an unplanned swap between its duplicate computer systems. This is the prescribed response by a spacecraft when it detects conditions outside the range of normal expectations; the safe mode is initiated to reduce the risk of whatever caused the out-of-range event from being repeated by the second computer and potentially permanently harming the vehicle while matters are investigated. MRO has experienced unplanned computer swaps triggering safe-mode entry four times previously, most recently in November 2011, the root cause of which still hasn’t been clearly determined.

The March 9th safe mode entry also included a swap to a redundant radio transponder on the orbiter, marking the first time this has happened during the vehicle’s eight years in orbit around Mars. Whether or not the transponder issue triggered the computer swap-out is unclear. However, after carrying out a series of diagnostics on MRO from Earth, the mission team began bringing the orbiter back-up to full operational capabilities on March 11th, leaving it operating on the computer the swap-out switched to, together with the previously redundant radio transponder.

“The spacecraft is healthy, in communication and fully powered,” Mars Reconnaissance Orbiter Project Manager Dan Johnston said on March 11th. “We have stepped up the communication data rate, and we plan to have the spacecraft back to full operations within a few days.”

Charting a New Frost Channel

Since that event, MRO mission scientists have released a photo comparison showing the active nature of the Martian environment. The image shows two pictures of the same slope in the wall of crater Terra Sirenum, located in the southern highlands of Mars. There were captured some two and a half years apart (roughly equivalent to 1.2 Martian years), in November 2010 and May 2013 respectively.

Side-by-side: an image of Terra Sirenum crater walls taken in November 2010 compared with an image of the same region taken in May 2013, complete with freshly-carved gully and outflow fan (light areas)
Side-by-side: an image of Terra Sirenum crater walls taken in November 2010 compared with an image of the same region taken in May 2013, complete with freshly carved gully and outflow fan (light areas)

The right-hand (May 2013) clearly shows the creation of a new gully down the inner wall of the crater, created when material flowing down the older channel broke out to form a new channel and corresponding fantail deposit. While the material responsible for the new gully was liquid in nature, as the event occurred in the Martian winter period in the southern hemisphere, it is believed that carbon dioxide ice, and not water, played the major role in forming the new channel.

NASA had previously experimented with dry ice to see if it could be responsible for such gullies, with interesting results.


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