There’s something afoot and it involves missing prims! Inara Pey has reported the issue in her update on Interest List and object caching but the problem seems to be spreading and the location of choice to spot the missing prims appears to be Tempura Island, as exemplified in a thread on the forums.
Basically what happens is that some prims aren’t rendering, you’ll see something like this:
If you look closely there’s a girl hanging in the air where there should be a prim, well the prim is there, hence why she looks like she’s floating, she’s not. Now if you look even more closely there’s a Linden in the foreground trying to figure out what’s going on, you get bonus points for spotting a Linden in the wild these days.
The problem is a little irksome but if you click on a prim or toggle off and on a graphics setting such as atmospheric shaders, the problem goes away. The bigger problem here is that if you’re not familiar with the layout of a place, you may not notice that there are missing prims in the first place.
All fingers at the moment are pointing to a client bug, but why would we be getting a client bug now? Well Andrew Linden has an update:
What has changed is that the server is now treating much more content as “cacheable”. The server’s definition of cacheable used to be something like: “is static and does not have a script”. The new definition of cacheable is: “has not changed position or appearance in the last couple minutes”.
The viewer bug must exist inside the code that retrieves object data from cache and is more noticeable now because the viewer-side object cache tends to be bigger. I’ve brought the problem to the attention of one of the developers who is working on some viewer-side changes that will compliment the next server-side interestlist changes (*), so we hope to figure it out soon.
(*) The server will soon support two hints from the viewer:
(1) “I don’t have an object cache file for this region at all” –> the server will then be able to bypass some of the initial “cache probe” messages of the protocol which looks something like this:
Viewer: Hello, I would like to connect.
Server: You are connected.
Server: Do you have cache for object 123 whose version is 456?
Viewer: No, I do not have cache for object 123.
Server: Here is the data for object 123.
Under the new system: when visiting a region for the first time the conversation will look more like this:
Viewer: Hello, I would like to connect, and BTW I can tell you right now that I have no cache.
Server: You are connected.
Server: Here is the data for object 123.
(2) “I’m willing to cache ALL object data in the region, including stuff that is too far away or too small to see” –> the server will eventually stream all cacheable data to the viewer, including sky boxes far above. It sends the non-visible data with a delay so that if you’re flying through the region on a jetpack and leave soon after arriving you won’t get the extra data, and once it starts sending the non-visible objects it will be in a lazy fashion — lower bandwidth than when sending what is in front of you.
A fix will be along at some point I’m sure, it’s not the biggest bug in the world and there are workarounds as I mentioned earlier in the post. The Tempura Island folks are probably enjoying all the extra attention too!
The Missing Prims issue certainly hits home with me as it happens every time I arrive at my home location, my little cabin in Winterfell Ebonshire. I have noticed the recent increase and been wondering about it. Right-clicking as if to Edit it works instantly and every time but is becoming annoying. Thanks to you and Inara for reporting on this.
The discussion is certainly gaining traction and the Lindens are looking into it, which is good. I’m definitely seeing more of it lately.