There is a lot going on in terms of projects and development work in Second Life. The following is a further update on a number of key projects I’ve been following and reporting upon through the pages of this blog.
Group Services Project
The Group Services project is an attempt to improve the management and editing of large SL groups by replacing the current UDP-based service (which has capacity issues with the size of group lists it can comfortably handle) with a new HTTP-based service. The project viewer for this is already available (for Windows, Linux and OSX.), as I reported last week.
This week sees the server-side code rolled-out to all three RC channels (Magnum, LeTigre and BlueSteel), allowing the project viewer to be tested in handling very large groups (significantly larger than are available on Aditi). Note that those running viewers without the new code on any RC region will be unaffected, as they will continue to access the current UDP service.
There are still no timescales as to how long the testing of the service will last (“It’ll take as long as it takes,” Baker commented recently), or when the viewer code will progress beyond the project viewer. However, a number of things should be noted in reference to the eventual roll-out:
- The viewer code is not being made back-compatible with V1 code by the Lab. Therefore, TPV developers using the V1 code base will have to backport the code themselves in order to use the new service
- The initial HTTP service roll-out does not include any data compression. This means there will still be some delay in downloading member lists for very large groups with tens of thousands of members
- Once the new service is rolled-out, which service is used is entirely transparent to the user. If a viewer with the new code is running on a region which has the server-side HTTP service, it will connect to that service. If it is on a region using the older UDP service, it will connect to that service instead
- Once the HTTP service is fully deployed, viewers which do not implement the viewer-side code will still be able to access groups with member lists up to 10K in size via the UDP service until such time as it is switched off (which will not occur for some time after the HTTP service has been rolled-out). However, attempts to access groups with lists larger than 10K will fail.
Interest Lists and Object Caching
To recap: when you enter a region at the moment, your viewer receives a huge amount of information on what requires updating, much of it relating to things you can’t even see from your position in the region. This information is received in no particular order, with the familiar result that things appear to rez in your view in a totally random order. Not only that, but the chances are that if you’ve previously visited the region, much of the information being sent to your viewer is already locally cached – but is being ignored. The focus of this project is to both optimise the data being sent to the viewer and the information already cached on the viewer with the aim of significantly improving object rezzing times in terms of speed and order (so objects closer to you rez before those further away, for examples).
Andrew Linden had hoped the project would be going to QA this week ready for roll-out to one or more RC channels in the near future, but some last-minute problems popped-up and have delayed things until he can get them sorted out. In the meantime, the code has been deployed to a number of regions on Aditi, and Andrew plans to, “Try to throw a pile of test avatars at it to stress it out. Later this week.” No viewer-side changes are associated with this work.
Work continues on the project to bring materials processing to Second Life. Last week, it appeared as if the new materials – normal and specular maps – would have their own rotation and positioning options independent of any texture (diffuse) map. This week, it appears that this is the hoped for situation, but the matter is still open to question – which goes to show how fluid the project is.
The new capabilities require changes to the rendering pipeline, and details have been released on some of what this entails.
In order to work, normal and specular maps require what is referred to as per-pixel lighting (as noted in the original blog post on the subject). As such, there has been a debate on whether it would be better to develop a per-pixel lighting framework within the viewer, or work to make the current deferred rendering system more accessible to per-pixel lighting capabilities. As the latter approach will allow getting materials processing working within SL sooner than would otherwise be the case, it has been decided to go that route. Thus work is focused on making the current lighting system more configurable and able to better handle a broad range of material types (metallic, matte, plastic, etc.), together with adding support for both per-object and per material shading differences.
However, a dedicated per-pixel lighting framework does offer advantages of its own, and as such is being considered as a possible future extension to the project, which may be implemented at some point down the road. One such advantage is that could potentially be run in a non-deferred mode, which might lightening the load on older graphics systems.
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