Revised #SL Mesh Arriving

The viewer using the new mesh format should be out Thursday of this week. The ADITI grids should have the new server side mesh software installed across most of the mesh regions. Mesh in ADITI will likely vanish as it is returned. New versions of user mesh will have to be uploaded. We’ll see an announcement when the sims and viewer are ready.

Update: See warning below.

#SL Mesh Design Blender 2.57b

#SL Mesh Design Blender 2.57b

New Format

With any luck the new mesh format will be published on the Wiki this week. That means OpenSim coders can start making their changes.

Pivot Point

Prep Linden removed the pivot point in mesh to correct problems on the server side. Prep thinks he can get to the pivot point and get it working before mesh release, which will make the pivot point code part of the initial release.


This one I don’t understand. See if you can make sense of it.

Runitai Linden: it should work — each instance should become a separate object and each of those objects should reference the same mesh asset

Drongle McMahon: … is that instancing of meshes or instancing of pieces within a model? …or just expanding instancing from the collada file?

Runitai Linden: expanding instancing from the collada file the collada file includes geometry nodes, and instance_geometry nodes we make a mesh asset for each geometry node

Drongle McMahon:        Ah yes…. not instances within an object then.

Runitai Linden: and an object for each intance_geometry node

Runitai Linden: so to keep the system simple, accounting ignores discounts from instancing. the only practical benefit for builders is your build will load more quickly and use a little less memory

Update: See: Mesh Instances for a better explanation.

LoD Settings

LoD is Level of Detail, there is a series of settings that trades off visual accuracy for better performance. The idea is that less and less detail is rendered as one moves away from an object. Most often people see LoD in action with less well made sculpties. As one moves away from them their shape degrades.

The various viewers have various settings for different LoD calculations, i.e.;

  • RenderAvatarLODFactor – Controls level of detail of avatars (multiplier for current screen area when calculated level of detail)
  • RenderAvatarPhysicsLODFactor – Controls level of detail of avatar physics (such as breast physics).
  • RenderDynamicLOD – Dynamically adjust level of detail.
  • RenderMinimumLODTriangleCount – Triangle count threshold at which automatic LOD generation stops
  • RenderShaderLODThreshold      – Fraction of draw distance defining the switch to a different shader LOD
  • RenderTerrainLODFactor – Controls level of detail of terrain (multiplier for current screen area when calculated level of detail)
  • RenderTreeLODFactor – Controls level of detail of vegetation (multiplier for current screen area when calculated level of detail)
  • RenderUseShaderLOD – Whether we want to have different shaders for LOD
  • RenderVolumeLODFactor* – Controls level of detail of primitives (multiplier for current screen area when calculated level of detail)

*This is the value typically changed from 1.0 to 3 or 4. Values higher than 4 provide little if any improvement. Several Third Party Viewers have a setting in Preferences for this value you can easily change.

Many residents tweak these values to get better rendering. Some viewers are now upping the default values of LoD settings to force the less well designed sculpties to render at the highest LoD at greater distances. The result is the server side systems have to download more information, or at least will with mesh, and the client/viewer to render more triangles in all cases. The result on older less capable computers is better renders and slower performance.

The SL default settings for these values can be found in the SL Wiki under: Debug Settings You can find more information about LoD in the Second Life Wikia (don’t confuse this one with the Second Life Wiki). You can see a video of LoD in action at Level Of Detail (LOD)

Mesh & Snowstorm Viewers

Mesh project code has merged with the Snowstorm Development viewer. However, the viewers are not exactly the same. If you are helping with testing use both viewers. The Snowstorm viewer is used for testing the mesh code in non-mesh areas on the main grid. The Mesh Project viewer should be used to test the new mesh format in the ADITI and in non-mesh areas in the main grid AGNI. Both viewers are mesh enabled. In non-mesh areas the mesh features of both are disabled and mesh menu items do not show.

Download the Second Life Development Viewer

Download the Second Life Mesh Project Viewer

Mesh changes and updates will appear in the Mesh Project Viewer first and more often. Snowstorm will be updated from time to time. Until know these two viewers were not as sync in as they will be now.

For those compiling their own viewers, the merged development viewer doesn’t build correctly. That fix is in progress. See STORM-1275

Current Team Priorities

This question is now a common question at the Snowstorm meetings. The current team priorities; mesh accounting, changing all code to the new mesh format, and fixing problems found in regression testing. Most of the regression discovered problems are with OSX shadows and anti-aliasing deferred rendering.

Testers for Mac should be testing shadows as much as possible as Lesli Linden is working on those problems now. So, test results will have the fastest effect right now. Make sure you send crash reports.

Joint Offsets for Rigged Mesh

Prep Linden says joint offsets are now working. If you are having problems, be sure you have the latest Project Viewer. Also look for joint import failures in the viewer log.

Effective Mesh Design

Large mesh objects will work better as multiple parts rather than a single large object, think buildings and houses. This is because at 64m dimensions the object will always display at the highest LoD.

For cars this idea translates to having separate mesh for the interior and exterior. No need to render a complex-steering-wheel-mesh for someone outside the vehicle.

Mesh ETA

The Mesh Team is making no comment. Several people are aware Tataru quoted Oz Linden saying in one of his meetings that we would have a mesh plan with an eta by the end of the month. See SLV 1.23 Life Expectancy.

Oops – Warning

There is a problem with mesh and sculpties in the latest current viewers. A bug in the mesh prep code is corrupting sculpties. this is real corruption and taking the sculpty object back into inventory stores a corrupted copy. This can be fixed, may be, by changing the sculpty to a box and then back to a sculpty. If the sculpty is no mod… you are probably screwed.


Mesh is getting close. The way the Lindens talk and the priorities they are setting I think suggest they can feel a due date drawing near. Hopefully we will have a time line the Lindens feel they can live with by the end of the month.

By the end of the week we will have the new mesh format and a viewer and grid updates to support it. We may see a rash of problems as the bugs in the code are discovered. They signal movement and will get fixed.

2 thoughts on “Revised #SL Mesh Arriving

  1. Check out what it says halfway down this post:

    re: “mesh-prep” branch.

    They’re rolling out code which will prepare the grid for mesh although it doesn’t yet include mesh features.

    Getting closer.

  2. Pingback: Tests of Mesh Import to Second Life Beta Grid and OpenSim 0.7.1 Live Grid | Ai Austin Blog

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