“Missing” prims: collaboration confirms viewer issue

As noted in my week 14 (2) update, prims missing from linksets  / builds is not a new issue, it’s been going on for some months now. In my own case, I’ve found that on teleporting to my home, an internal wall I’ve added to the build is routinely missing from my view. Right-clicking on the area of the wall has caused it to immediately render. As the wall in question tends to rez OK when I log-in to SL, I’ve tended to look on the matter as a viewer issue.

However, following the week 14 deployments, the incidences of missing linksets seems to have both risen in both numbers and size of “missing” prims. There have been numerous reports on the deployment discussion thread, including questions as to whether it is a viewer issue or server issue, and things seem to have become a lot more visible.

My Linden Home and "missing" prims on Wednesday 2nd April
My Linden Home and “missing” prims on Wednesday 3rd April. House is located on the SLS (Main) channel

My personal experience has been that things are worse – as shown in the image above. Prior to the April 2nd, The wall on the far side of the house, with the two pictures and turning to run under the bedroom balcony rails, would fail to render following a teleport. Since the Main channel deployment on Tuesday April 2nd, that wall now renders flawlessly – but a huge section of the linkset for the house itself is almost constantly missing following a teleport home. Camming around my home region reveals other houses in the same condition.

Such has been the level of discussion on the thread about the matter, lead by Wolfbaginski Bearsfoot and others, that Maestro Linden stepped-in and posted some pointers to help people determine if they have a viewer or a server-side issue, stating:

Hi Wolfbaginski, I would do the following to determine whether objects are missing due to a server bug or viewer bug:

1) Note whether the missing objects are whole linksets or only certain prims in linksets.  Interest list issues would generally affect whole linksets.  A viewer rendering issue or maybe a message-packing/decoding issue would seem more likley if only certain prims in linksets are affected.  It sounds like you’re seeing at least part of the linkset, since you’re able to select it.

2) While the prims are missing, enable Develop -> Render Metadata -> Bounding Boxes, and see what bounding boxes appear.  You should see a prim-aligned bounding box for each prim, as well as a world-aligned bounding box that covers the linkset.  If you see a bounding box where a missing prim is located, or if the linkset bounding box extends to include the missing prims, then it’s almost certainly the viewer’s fault.  

3) While the prims are missing, enable Develop -> Show Info -> Show Updates to Objects.  With this setting enabled the viewer will render a particle from each linkset/prim that it got an update for:

  • Red means a full update was received from the server (which has a full description of the object’s visual parameters)
  • Blue means a terse update was received (which only includes information about a few properties, such as position and velocity)
  • Green means that an ‘objectdelete’ update was received (meaning that the object was either derezzed or is out of range for the viewer)

If you enable this feature, and observe that the missing prims appear without a full object update being sent, then it’s probably a viewer bug (in that the viewer knew about the missing prims the whole time, but initially failed to render them).

 4) If you leave a region, then return to it, the viewer will load cacheable objects from the local cache, instead of getting the object details from the simulator.  If the object was loaded from cache and the appearance has been either fixed or broken since the last time you saw it, this would indicate a viewer bug.  You can verify that an object was loaded from viewer cache by enabling Develop->Rendering Metadata->Update Type; objects loaded from cache are shaded blue, with this mode enabled.

Diagnosing the issue: only a part of the boat appears to render (black areas); however, turning on Render Metadata reveals the viewer is aware of the rest of the build - but not rendering it
Diagnosing the issue: only a part of the boat appears to render (black areas); however, turning on Render Metadata reveals the viewer is aware of the rest of the build – but not rendering it

As a result of this, a healthy exchange started between users and Maestro, as Wolfbaginski noted in his feedback to my original report, with further tests being carried out. The discussion further confirmed that the problem appeared to be worse since the deployment on April 2nd, but that findings pointed to the issue being more towards the viewer end of things than the server – and that the problem was as prevalent in the recent SL viewer releases as it is in “older” TPV releases. The discussions also lead to some feedback on how to force “missing” prims to appear, including:

  • Flicking alpha masks off & on
  • Toggling Atmospheric Shaders in Graphics Preferences off and on.

The result of this collaboration was an update from Maestro Linden, posted to his original notes (above) which reads:

I investigated this on region LEA27 on Aditi.  This region has 25k prims, which are all identical mesh boxes.  They are arranged in pretty patterns, so it’s fairly obvious when some are missing.  I found that some prims in linksets ‘randomly’ (different linksets are affected each time I visit the region) don’t render until selected.  All of the debug settings indicate that this is a viewer-side issue.  I used ‘Second Life 3.4.5 (270263) Feb 12 2013 04:36:12 (Second Life Release)’ to test.  I didn’t see an existing Jira for this issue, so I filed a new one internally.

How long it might be for any fix for the issue appearing as a result of Maestro’s JIRA obviously isn’t clear at this point – and there is a lot going on with the viewer at present. However, the important aspects of this are that:

  • Good collaboration between users and LL has led to an issue being positively pinned-down
  • A JIRA on the matter has been raised internally within LL and will as a result be getting attention
  • There are some alternative “fixes” available for the problem should you witness it (right-click on the missing prims,  flick alpha masks off / on or toggle Atmospheric Shaders).

If you encounter the problem, and while it is frustrating, try one of the three solutions above.

Related Links

With thanks to Wolfbaginski Bearsfoot

17 thoughts on ““Missing” prims: collaboration confirms viewer issue

  1. And I’ve had missing attachment issues for quite some time. I’ll do some testing of my own and I’ll send You the results, if You think they’d be useful.


  2. Hopefull this colaboration will extend to further issues!
    And even more hopefull, LL will aknowledge that is healthy to share and listen to its community, not only regarding bugs but in all areas!


    1. LL pay far more attention to issues / bug than they are given credit. While the majority of JIRA are annoyingly closed to public access (rather than simply having comments disabled – which would have been a far better solution, as people could at least track progress on issues), doesn’t mean they are ignoring things.

      In many respects, bug-stomping is a two-way street; not every issue users encounter is easily reproduceable. As such, filing JIRA and / or giving as much detail as possible (such as ciewer being used, simulator version, region name, time of event, circumstances, etc.) in forum posts is vital in helping LL have a chance to pin-down isues for themselves.

      In some respects the recent interest list releated region crossing issues were a case in point – a lot of people were understandably upset, but it appeared as if no-one was filing specific JIRA on the matter. Result: LL were paddling around in circles, picking aircraft types at random and carrying out random tests in the hope of getting a consistent set of repros, and not meeting with particular success.

      However, as soon as a detailed JIRA was filed (BUG-1814), the Lab were able to repro the issue clearly & concisely and pin-down the underlying cause. That lead to a fix being developed and deployed in relatively short order.


    2. It’s always vital for a developer to be given concise and detailed information regarding bugs and other problems, as in “when I use this object, this viewer, this release, with this system configuration, in this region and this is also happening, I encounter this problem.”

      When the general public’s attitude is “you messed up, now fix it” or “you broke it, it doesn’t work”, instead of what I mentioned above, even the most patient developer is bound to eventually be led to unflattering conclusions about the users and stop bothering.


  3. Everytime i TP to some airport sim, always are runway parts not rezzing. other words invisible. with 1 click you can indeed make them visible. since LL cant make a good viewer your stuck with TPV viewers. and maby also stuck on fixt problem in SL viewer. (wish the fixt some otehr problems in viewers to.


  4. So if I’m reading Maestro’s responses correctly:
    * Everything points to a viewer issue
    * Every viewer he tested has the issue (including SL’s viewer)

    Since all viewers didn’t change all at one time, and all of a sudden all viewers have the issue….I have to wonder if yes maybe it’s a viewer issue, but it’s caused by a server change that changed how things work.


    1. There are ongoing changes to the server-side, perhaps most noticeably with the interest list (which manages the information which needs to be sent to the viewer in order for it to know what to render). The updates to this deployed this week include, among other things, changes to how object data is cached locally for re-use (the definition has been broadened), and this might have brought the issue more fully into prominence.


      1. I cannot pin down just when it started, but having attachments missing components (such as my ears) has been going on for a long time. Oh, the joys of ursine life! The more general problem, prims not rezzing in the scenery, has been more recent, There were places I regularly saw it, and the right-click work-around was effective, Butm with the roll-out on Tuesdaym it started happening more often, and in more places.

        I am often advised not to clear cache. I may ignore that advice tonight.

        The flying is pretty good. Anyone want to see how many Spitfires we can get in the air together?


        1. Ironically, this afteroon I gave up on flying due to the SL viewer refusing to render worn attachments AND refusing to attach HUDs. Certainly, as indicated in the article, I’ve noticed a huge increase in n-world linksets borking since Tuesday’s deployment. Doubtless questions will be asked at the Server Beta meeting.

          As to getting Spits in the air – I’m up for it! Problem is, outside of Erick, I dunno anyone who flies one! But yes, doing a “Duxford” could be fun, particularly if we could form-up in vic or something (see, I’m even learning the terms!).


  5. I wonder if this is in any way related to the issues i have with combining Alphaflipping animations with pathfinder scripts which cause my mesh object to disappear when moving. With have to use the suggested tests to see what results i get.


    1. Just to clarify, with Develop->Rendering Metadata->Update Type enabled, what does RED colour mean, and what does it mean if an object does not show up at all in any colour in the viewer until you right click it?


      1. There are trhee colours of update, as follows:

        • RED – A “full” update – required when an object is “seen” for the first time or which is constantly updating position / appearance
        • BLUE – A “terse” update – required only when an object is changing appearance / position relative to the viewer’s in-world view
        • GREEN – A “please delete” update when the object has been removed from the viewer’s in-world view (e.g. it has been deleted or taken back to inventory).

        See: Interest List Update.


  6. On Spitfires and stuff:
    What we need is a “Balbo”: they seem to have them at Duxford every year and there is a plethora of videos on YouTube.

    Can’t think why…

    Sometimes I fly the THI Spitfire, which is maybe a little easier to fly for just cruising around. Erick’s Mk. IXC is a bit more of a challenge. Now, where can we find a sucker volunteer to fly a Dornier?


  7. Parts of my house had disappeared on Saturday night and no amount of right clicking or relogging would rerender it. Friends – also using FS – saw exactly the same as me. It was in an identical state all day yesterday until in frustration I took the whole build down and rerezzed it. I shall see what has happened today when Iog on later. If the disappearing prims are actually there, however, would they not have interfered with the rerezz? All very strange.


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