Project Bento User Group update 5 with audio

Project Bento extends the avatar skeleton, adding a significant set of bones (e.g. 30 for the face, 30 for the hands Project Bento - extending the SL avatar skeleton

Project Bento – extending the SL avatar skeleton

The following notes and audio were taken from the weekly Bento User Group meeting, held on Thursday, February 18th at 13:00 SLT on Aditi.  For details on each meeting and the location, please refer to the Bento User Group wiki page. Audio extracts are provided, however, due to circumstances beyond my control, I missed the first 20 minutes of the meeting, so the following update is not a full summary of all that was discussed.

The Default Avatar Mesh and Bento

An area of concern regarding Bento is that while custom-built avatars can make use of the new Bento skeleton, and some work has been done on making some of the appearance sliders for the default avatar mesh compatible with Bento, there is next to no way at presents for the default Second Life avatar mesh to make full use of a Bento extensions. Much of this wouldn’t actually matter,  given that many of the circumstances where the new bones are being used would likely require the use of a custom mesh avatar. However, there are two noticeable areas where the it does have an impact: hands and faces.

Essentially, Bento introduces 30 bones into the face and 30 bones into the hands. However, these cannot currently be leveraged by the default avatar mesh, as demonstrated in the first 20 seconds of the video below.

As such, there has been discussion over the last couple of Bento meetings on ways in which this might be addressed. However, there are significant problems in trying to make the existing default SL avatar compatible with the Bento skeleton. One of these is that the default skeleton is designed in three core sections (head, upper body, lower body), each of which can only be rigged to utilise a maximum of 15 bones.

This means that trying to rig the default avatar to make correct use of the Bento skeleton additions isn’t that easy; the head and hands, for example, simply cannot support the number of bones offered by the Bento project. A further complication as that when it comes to facial expressions, the default avatar uses morphs rather than pure animations to achieve various expressions, and these could conflict with animations which utilise the Bento bones.

One solution would be to completely overhaul the default avatar or replace it. However, this is a massive undertaking, and one which could easily result in a lot of existing content breakage, as such it is not something the Lab is entirely sanguine about doing. Another idea put forward was for the Lab to provide two default heads, one utilising the default morphs and the other Bento bones and their associated animations. However, the limit of how many bones the default avatar mesh can support made this idea a non-starter.

Cathy Foil summaries the discusses on the avatar head, which occurred prior to my arrival at the meeting

During the discussion, Vir and Oz revealed that having the default avatar make use of the Bento skeleton is something the Lab has been pondering. However, it is not something that will be implemented during this initial phase of Bento due to the amount of work involved. However, it could be looked at as part of follow-on work from Bento.

Vir and Oz Linden raise the potential for Bento follow-on work to provide a means of making the default avatar head and hands more compatible with the Bento bones

That the Lab are considering trying to make some changes to the SL default avatar to leverage Bento capabilities lead to the suggestion by Medhue Simoni that perhaps the Lab should at the same time more broadly overhaul the avatar to provide a consistent set of vertices and weights throughout.

The idea here would be to present an avatar form which content creators could more readily use to model and rig fitted mesh items to a single, consistent set of vertices and weights, rather than each having to work to their own weightings. This would allow fitted mesh clothes to work more precisely with the avatar appearance sliders than is currently the case, and thus provide a more consistent and better feature set going forward.

The problem here is again exiting content breakage. One suggestion for dealing with this, put forward by Cathy, is that if the Lab decided to go the route suggested by Medhue, they could need to provide two default avatars, which users could swap between as needed dictated, by means of something like the gender change options currently found in the avatar appearance panel.

Comments on a wider re-working of the avatar skeleton

Appearance Sliders and Bento

As noted above, there has been some work completed on hooking some of the Bento bones to the appearance sliders – notably around the head and hands. Now that the updated skeleton is moving towards a final design, the hope is that perhaps more bones within it can be linked to the sliders.

Vir and Cathy on Bento and the appearance sliders

“Unwearing” the Default Avatar While Allowing Baked Textures

A suggestion has been put forward as a part of Bento to make the default avatar “unwearable” (i.e. allow it to be removed) and  allowing mesh avatar bodies to directly use the baked skin and clothing layers within the system (see BUG-10980, and the similar but independent request, BUG-10495). Doing this would provide a number of advantages, both in reducing the complexities of making and wearing SL clothing utilising the baking system, and in improving the overall efficiency of the available mesh bodies by reducing their overall polycount.

This is something Vir feels strikes a good balance between feasibility and benefit, and it is currently under consideration as something the Lab may undertake as they determine follow-on work from this initial Bento project. However, no final decision has yet been made on whether or not it will be done, and it will certainly not be a part of the initial Bento release.

Vir on the idea of making the default avatar mesh “removable”

Default Avatar Pose Issues

There was further discussion on the avatar default pose issue I’ve reported on here and here, with it again noted the problems appear to be routed in message timing issues which can occur between the server and the viewer, which result in a default animation being played by the server, rather than an expected scripted animation, which can cause odd results (such as a quadruped avatar crossing its forelegs like a humans folds their arms).

The suggested solution for this is to use the llSetAnimationOverride capability introduced in 2013. However, As most scripted AO systems lean towards using one or other flavour of the ZHAO scripted animation system, which pre-dates llSetAnimationOverride, it means there will have to be a widespread re-writing and dissemination of updated AO systems, which might take time.

The animation override issue discussed.

Facial Bones, Defaults and Rotation / Translation

There was further discussion about bone placement, approaches to animating facial features, the potential to develop a “standard” or “default” approach and whether that should be based rotation or translation of the bones. Cathy indicated that a default could be set using the “standard” female avatar (on which most of the Bento facial work has been based), with the avatar LAD files used to shift these for use on male avatars.

She also discussed shifting the facial bones closer to the surface of the avatar. Some of this discussion took place prior to my arrival, with Cathy indicating that moving the bones too close to the surface of the face could limit bone animation to just translations. She later expanded on how any need to have bones nearer the surface of the face might be met through the bone end points, which I did catch in my audio recording.

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