SL projects updates 20/1: server, viewer, LSL and materials

Server Deployments, Week 20

There was no Main channel deployment or rolling restart on Tuesday May 13th, and neither the BlueSteel or the LeTigre RC channels will receive an update or should undergo a restart on Wednesday May 14th.

The Magnum RC should receive a new sever maintenance project on Wednesday May 14th, which includes a bug fix for a networking-related issue that sometimes affects busy sims.

SL Viewer Updates

The SL Maintenance viewer was updated on Monday May 12th to version 3.7.8.289922. This viewer includes multiple fixes to Mac viewer; fixes in Recent tab, Chat, LSL editor, land management, etc; GPU table updates; crash fixes & performance improvements.

LSL Functions for Materials

The subject of scripted control for materials was once again raised at the Simulator User Group meeting on Tuesday May 13th. Commenting on the matter, Simon Linden said:

I am looking at it but not promising anything. We’re trying to be really careful to understand how the server and viewers will react when stressed with a lot of material churn. From what I can tell, fast-moving material-based animation will not work well … that’s likely to be throttled or blocked somehow. But supporting something like a hud or other control that could adjust the look of an object … where it’s done rarely … is definitely possible.

As noted the last time this subject was raised, there are concerns over how LSL control of materials might impact system performance, either deliberately (via rapid and multiple flipping of maps, hence Simon’s comment on throttling the speed at which changes could be made), or unintentionally, such as using them with objects which may already have a large performance impact (such as animated mesh tails).

During the meeting, there was discussion on options for animating normal and diffuse maps, remembering that they can already be animated in lockstep with their attendant texture (diffuse) map. During this discussion, Simon commented on some of the difficulties in animating  materials independently of the texture map:

The materials LSL support would include changing the offset, repeat and rotation values for the two maps, just like for regular textures. The update problem hits if you look at the way materials have been optimised between the server and viewer and how updates are sent. Materials are referred to by a number ID … so you get updates that say “this face has material 1234” on it, the viewer, if it doesn’t know what 1234 is, has to ask the server.

Now, if you change the offset … you have a new material 34356, the viewer has to again find out what that is, but this time it already has the actual specular and normal maps, so no download there.  And when you switch back to 1234, it has all the info and can draw it faster.

Summing-up the situation in general, Simon concluded, “I hope there will be something to play with eventually on the beta grid … we’ll probably want to experiment there and figure out what kind of limits are effective.”