#SL Mesh Group Update Week 37

Most of the work Lindens are doing in regard to mesh just now is to stabilize the viewer and servers, mesh problem fixing and performance improvements. Today they went through answering questions posted to the meeting agenda, a typical meeting with some interesting items.

Mesh 11-09-12

Prim Equivalence

By now you probably know Prim Equivalence (PE) is a complex way of representing how mesh uses up render resources. It is confusing, especially if one does not read how it is supposed to work in the wiki. Most people don’t bother to read the wiki. After finding they can’t figure it out, they complain in the forum and blame the Lindens for a dumb idea that is broken. Well… if one make an attempt, it is not too hard to understand.

One of the biggest problems is from the choice of label; Prim Equivalence. People take the meaning of the term literally. Then they try to figure out how many polygons are in prims and then compare their mesh and get confused. So, finally the Lindens are changing the label. PE will become Land Impact in the future. The newer development viewers are already changing the labels.

Second Life

New Build/Edit Panel

New ARC Algorithm

With the arrival of mesh and new methods of figuring Land Impact (LI) the Avatar Render Cost (ARC) is out dated. It has been revised and is now using new values in the Mesh Development viewer (3.0.5). Advanced (Ctrl-Alt-D)->Performance->Avatar Render Cost or now: Show Draw Weight for Avatars. So, may be ARC is changing to DWA… or DWoA.

When wearing a favorite hair and a complex necklace my avatar has an ARC of about 12,000 in the old ARC system. In the new ARC system that value jumps to 228,580. A nude avatar had and ARC of 100. A nude avatar has a DWA of 1,000.

Along with the ARC changes comes a revised ORC, Object Rendering Cost. See the Edit/Build panel to see the ORC. Press Ctrl-B to open the panel or click Build in the top menu. You must be in an area where you are rez eneabled. The image shows the old and new versions of the panels. There is also a subpanel you can open by clicking MORE. The subpanel gives more information about the object and the component parts that make up the Land Impact value.

One of the factors in DWA is texture image size and the number of textures.

If you want more technical information on the changes from viewer 1 to viewer 2 and 3, see User:Nyx Linden/Revisiting Render Cost. The real life facts of 3D rendering are complex.

I expect we’ll have some problems with the changeover. Some regions eject people based on ARC, or so I hear. The change to higher ARC values may mess up those systems.

Market Place Problems

Many of the mesh items in the Market Place have misleading information about the items for sale. Some people are marking the items using the prim count rather than the PE or LI values. So, customers are having problems when they rez the objects. It will take some time for the correct labeling to start to appear in the Market and stores. For now it is buyer beware.

Mesh and Avatar Appearance

One of the problems with avatar clothes made from mesh is the mesh does not react to most of the appearance sliders. So, we are seeing people have to change their shape to fit in their clothes. If RL were so easy…

Some people work hard to get their shape just right. I’ve worked on mine for some time. I still tweak it now and then. So, changing shape just to wear clothing items does not go over well. However, I’ve got a shape just for SL skirts. But, that is to make the skirt look like my non-skirt shape… if that makes sense.

Maxwell Graf opened a JIRA to request that the mesh respond to the appearance: SH-2374. (It should be viewable now. It disappeared when the Lindens put it into their planning. It’s a problem with the SH category.)

Runitai Linden says it’s under investigation and they are exploring solutions to the problem. This is good news in that they are looking at fixing it. It is downer that it’s in study and not being coded. Charlar says this feature/fix is behind stability in the priorities.

Forum Tutorials Section

Some thought is being given to creating a section for tutorials in the SL Forum. The Lindens are hesitant to make or request changes. One can read into that what they want.

One can add tutorial lists to the wiki. One just has the problem of so few people using the wiki or knowing how to create or edit pages there.

All LoD’s in One File

Many modeling systems allow one to place all the LoD‘s and the physics shape in one file. This is one of those items the Lindens have placed in the backlog. Adding it would make it like some other games that load files as LoD’s or physics based on the file name.

Pivot Points

Several modelers want these. In Blender it is the pink dot that is center of the object. The SL importer does not use offset values for user positioned pivot points. See CTS-297 and CTS-496. Prep Linden tells us they will not be in the Second Mesh Release. They still need to make some server changes before they can implement them.

Bone Offsets

Prep says he will be adding the ability for the uploader to handle the bone offset information.

There are some posts in the forum about how to patch Blender to get bone offsets working. It has to do with bone rotations.

There is some word that bone offsets work better with the thin female shape in the Linden avatars. The Lindens are looking to see what that is.

Morphing Sort of…

There is something about an unsupported way to morph mesh that was found in the closed beta days. See: How to: Morphing avatar meshes… sort of. Prep says he has not checked out. But, hopes to have something to say at some point as he gets into the next mesh upgrade.


In the mesh uploads panel there was the option to select NONE for the LoD level. The model would then render using the next higher level. The Lindens decided NONE was causing confusion. It now says Use the LOD Above.

Summing Up

Busy meetings. Some agenda items were people asking about bugs or whether an occurrence was a bug or intentional behavior. Several people are submitting files so the Lindens can examine problems encountered.

We are getting lots of questions answered but not much news about coming features and changes.

5 thoughts on “#SL Mesh Group Update Week 37

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