Project Bento Resources and Information

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Welcome to Project Bento! As we mentioned in our announcement, Project Bento is adding new bones and attachment points to the avatar skeleton.

Project Bento Testing is now Complete! Project Bento is now Live in all regions on all viewers!

This page has been re-purposed to be Project Bento Resources / Best Practices!

What is the test period for? How long will it last?

The testing period for Project Bento is now over!

However, as always if you discover an undocumented bug please report it at JIRA with the tag [BENTO] for it to be properly addressed!

What is Project Bento??

Project Bento is an update to the Second Life Avatar Skeleton which is what allows Second Life Avatars to move and come to life, as well as enabling the creation of rigged mesh attachments.

Bone Updates

The Project Bento Update added bones to the skeleton to expand rigging and animation support in the following areas:

Facial Area (new)

Spine (additional bones)

Hands (new finger bones)

Tail (new)

Wings (new)

Hind Legs for Quadruped Avatars (new)

A full list of the alterations for the skeleton exists here.

Slider System / Shape Updates

Additionally Project Bento updated the slider system to move these new bones with the Avatar Shape system.

Scope of slider interactions

While the updates to the slider system made it so that these new bones move with sliders, it does not override, or affect in any way existing behavior on the default Linden Avatar head and hands. The default Linden Avatar depends on morph targets to perform hand poses and facial expressions. This is a completely different system from using bone based rigging on mesh attachments worn in the same regions of the body (which is what Project Bento adds support for). While these two systems are affected similarly by slider manipulation by design, it is good to keep in mind that it is an approximation, and only that. It is fundamentally impossible to exactly mimic the motion of a morph target based system with a bone based rigging system. For example : sliders will affect a mesh attachment head differently than it affects the Linden Avatar head. This is unavoidable due to how both systems differ mechanically.

Animation File Updates

On top of additional bones and slider integration, Project Bento also increased the maximum allowable size of animation files, and also removed the restriction on BVH animation file uploads that prevented translation based bone movement.

Caveats & Best Practices

  • Due to the restrictions of the pre-existing Second Life Animation System. Playing animations that affect bone scale will (continue to) not work with Project Bento, however the slider system has been incorporated to adjust bone positions and bone scale.
  • Any slider controls that affect the position ( translation ) of a specific bone will be overridden if the user plays an animation that moves that bone. Since presently the animation system has no means of knowing the positional offset that the slider is providing, that animation will be played based off of the bones natural ( pre-slider adjustment ) position. However the influence of the affected bones scale will not be altered.

Because of the above two restrictions it is ill advised, to mix content where you want the translation based sliders to work with translation based animations. Because the animation will always override the slider. For a list of all the bones that are influenced by sliders that adjust their position refer to this :

This was the best practical alternative to simply not allowing translation based animations at all due to the possibility of them overriding sliders. The community asked for the ability to have translation/position based animations available for greater creative control and it was agreed upon that suffering the confusion from this conflict of behavior was still an overall gain.

Current Content & Resources

Models & Skeleton Files / Test Content

Note: to add new test content to the wiki, you can first attach it to BUG-10981, then post a link to that attachment in the wiki. The wiki does not allow attaching most file formats directly.

Collada (dae) files:

The following model files are compatible with the current project viewer, as of 2016-07-14, and should work with currently implemented sliders. Includes weighting to the new mFaceJawShaper bone.

Maya (ma) files:

These are also current with the skeleton of July 14, 2016:

(NOTE: Standard Skeleton with bone located in standard positions determined by the avatar_skeleton.xml file.)

(NOTE: Standard Skeleton with bone located in standard positions determined by the avatar_skeleton.xml file.)

FBX files:

These are based on the Maya files above.

3ds Max (max) files

All files are saved as 3dsmax2012 files, if your version predates this, they probably won't load.

"Basic" skeleton files contain no additional nodes and will not work for advanced control rigs and animation export, but are simpler, contain less clutter and might be ideal for simple rigging&skinning work. However bone rotation axis will not behave ideally for animations.

"Normal/Animation" Rigs have additional nodes for ease of use with animations, but animation must be done on "mBoneName_DRV" point helper nodes instead of the bones directly. These skeleton files have nodes oriented in a manner that will make joints rotate on their local axis. This is particularly useful for mimicing animation in parts of the bento skeleton such as the hands and face where the bone is not aligned with an axis ( perpendicular to other things in the scene ). Hopefully these skeleton rigs will help understanding of the new joints.

For both skeletons ( both "basic" and "animation" ) the mesh skinning and rigging should be done to the mBoneName or "collision volume" (fitmesh) bones / dummies only. All skeletons are default (female) bone positions ONLY.

Dec, 2016 update fixes minor rotation issues in the collision volume bones that existed in the initial August 2016 posting.

Test Animations

Animation Export Tools


The following tools are used for export of BVH files from Autodesk Maya Software. The exporter was authored by Aura Linden and is available for free below.

It works ideally with the skeleton included in Mayastar, maintained by Cathy Foil. But should be able to be used as a standalone script as well.


While blender does not have any freely available animation exporters, it has an excellently maintained plugin package known as Avastar maintained by Gaia Clary.


Autodesk 3D Studio Max presently does not have any publicly available animation exporters. However, polysail resident is presently working on a plugin that will do so. Completion date is TBD.


Scale Locking Option

With Project Bento, the option to have an uploaded mesh attachment completely ignore all slider input was also added.

When you upload a model beneath the standard "Include skin weight" and "Include joint positions" check boxes, there is now an additional check box for "Lock scale if joint position defined". If you check this box, then any joint that has a position defined will also have its scale locked. Scale locking will be enforced whenever a joint would normally be scaled by a slider thus "immunizing" it to all slider influence. To make a bone truly slider-proof, you will have to pay attention to the joint hierarchy. Any change to the scale of a parent bone will also cause the child bone to move, so you will have to make sure the bone's ancestors also have joint positions defined. A joint position will be ignored unless it differs from the bone's default location by at least 0.1 mm (ie, 0.0001 m in the units used by the skeleton definition file). If you want to lock a joint without changing its position, use a very small offset that will not be large enough to have a visual effect (some fraction of a mm).

I found a problem? How can I give feedback?

  1. Submit bugs in Jira in the BUG project: please put [Bento] in the summary line.

If you have a display problem, please try with hardware skinning enabled and disabled

Me->Preferences->Graphics->Advanced->Avatar Rendering->Hardware skinning checkbox

Does changing that setting affect the display?