Practical observations Rigging and Weighting The Skeleton and the associated Shape key system provide:Р”Р€0 of the shape keys influence the Mesh and/or the Skeleton and thus they can be used for limited customization of custom meshes. But currently it is not possible to weight attachment points in a reasonable (safe) way. We believe that your viewer should be able to use the attachment points exactly like all the other bones, and thus give us 32 extra possibilities for weighting and animating our meshes, and that the existing limitations should be viewed as bugs. Either it gets ignored or the entire armature gets distorted.

Again unlike normal bones it doesnРІР‚в„ўt appear possible to change the location of the bone with a custom mesh import (Adding joint offsets to attachment bones).

To fix you need to run an animation which rotates the bone to zero again. Unlike the normal bones, stopping an attachment bone animation will leave the bone in the last rotated position. Collada 1.4 doesnРІР‚в„ўt support bone names like this consequently a bone like РІР‚СљLeft ShoulderРІР‚Сњ is interpreted by the Collada Importer as 2 bones with the names РІР‚СљLeftРІР‚Сњ and РІР‚СљShoulderРІР‚Сњ respectively, thus the Collada data will be invalid.

Some attachment points have spaces in their name.

The main limitations weРІР‚в„ўve discovered are:

The only reliable way to get good results: Use clean PIVOT Rigs and avoid using Joint offsets when you try to match items to the system character.

Otherwise you loose precision in the meshes.

Forget to import clean PIVOT Rigs with joint offsets.

Otherwise you lose precision in the meshes.

Forget to make Mesh characters by using the POS Rig.

Also Bones with Joint Offsets behave different from Bones without Joint Offsets. Second Life uses 2 slightly different Rig definitions for the System character and for your Custom meshes. And this has major consequences and you end up with a shape that no longer matches to the System character mesh, even when the mesh itself does match perfectly on vertex level. That means for the Collar bones and Shoulder bones: When you move the Torso Shoulders Slider then it just does not work any more. Technically it loses the ability to follow translations. When a Bone has a Joint Offset then it gets treated slightly different by the Appearance system. But the Mesh gets bound to a PIVOT Rig and so it will match better when you compare it to the System Character. When you use a clean PIVOT Rig for your mesh character then an import with Joint offsets uncorrectly detects joint offsets for some bones. Each vector defines the distance to the parent joint: Below you find an excerpt of the Rig definitions. The reason for why those 2 rig definitions exist is unclear and buried somewhere in ancient history of Secondlife.

In short POS and PIVOT are 2 definitions of the Secondlife Rig which are almost identical but differ a tiny bit from each other. But what is that and how do we work with this? In fact this is one other source of misunderstanding, misbehavior and its quiet badly understood by everybody, even by LindenLab them self (i believe). You may have seen that Avastar supports 2 Joint Types, namely PIVOT and POS. Now you wonder why this is important even if you do not at all use the appearance sliders? In fact the appearance sliders take effect even when you wear a default shape. So even if the mChest bone plays no role in the character weighting (in our example) it still affects all its children as far as appearance sliders are concerned, because it reacts different to the appearance sliders when it has no joint offset defined. This is done by using the Fitted Mesh bones, or more precisely the Collision Volume Bones to the mesh.Р”Р„nd this is evil! The problem is with the Appearance sliders: In that case any joint translations (location moves) defined in the appearance sliders are not applied to bones with joint positions.

The basic idea is to let more Appearance sliders control the mesh. This is where the Fitted Mesh addition steps in. However this means you create your content by using the Second Life Restpose which does never match the actual Shape that you use in Second Life.Р”Р„ctually we want to create attachments which can be adjusted (fitted) to any shape. But this information is normally not available outside of Second Life.Р”Р‡ortunately you can get around this problem by using the SL Restpose for your work in your 3D Editor. So if you want to create a specific mesh attachment for a specific shape then you need to know exactly how the shape values are related to the joint positions (and bone scales) of your particular shape. This is controlled via 20 of the available shape parameters (appearance sliders) for the Legacy Skeleton and 40 additional parameters for the Extended Skeleton (mostly for the Face expressions and Hands). It is important to always remind that your Avatar Shape settings in your viewer effectively change your skeletonРІР‚в„ўs joint positions and Bone Scales.

Second life bento skeleton color chart