Project Bento User Group update 21 with audio

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, August 4th at 13:30 SLT at the the Hippotropolis Campfire Circle. For details on the meeting agenda, please refer to the Bento User Group wiki page.

Note that this update is not intended to offer a full transcript of the meeting, nor does it present the discussion points in chronological order. Rather, it represents the core points of discussion, grouped together by subject matter were relevant / possible, whilst maintaining the overall context of the meeting.

Lab Summit Feedback

Troy and Vir attended an internal Second Life summit at the Lab, where Troy gave a further presentation on Bento to the rest of the Lab’s SL staff and senior management, all of whom where very excited about the project. During the Bento meeting, Troy again offered thanks to all who have contributed to the project and who are endeavouring to make Bento a success.

Updates and Bugs

As Vir has been on vacation, there have been no further updates to the viewer since the release over version 5.0.0.317597, which the Lab hopes marks the end of updates to the enhanced skeleton and the revised appearance sliders (although obviously, the viewer will continue through project/RC releases to a final release down the road). However, a number of bugs have been reported against this update, with discussion on the forum thread on whether the problems lay within the Bento updates or elsewhere.

One of these, BUG-37546, relates to facial bone joint offset issues, which I’ve reported upon on previous Bento updates, and which can cause the collapse /deformation of any face using custom offsets as soon as it is worn, or in the view of anyone else seeing it for the first time, with both issues requiring the wearer to play an animation against the offsets in the facial bones will witness an immediate collapse / deformation of the face until such time as the wearer runs the animation against their face.

Teager offers this example of the facial problem - note the horse's collapsed nostrils, the drawn back lower jaws and the teeth protruding through the lips - all issues which have appeared in the viewer update

Teager offers this example of the facial problem – note the horse’s collapsed nostrils, the drawn back lower jaws and the teeth protruding through the lips – all issues which have appeared in the 5.0.0.317597 viewer update

Teager has been experimenting with the issue at length in an attempt to try to isolate possible causes. In doing so she has identified that this deformation can occur whether the mesh is weighted or not, and it doesn’t seem to be related to the facial appearance sliders or any conflicts caused by adjusting them.

Gaia Clary has also been looking into the problem, and may have come across a partial cause of why things like the lower jaw are getting “pulled back” into the face when seen in the viewer. As she explains in the Bento forum thread subsequent to the meeting:

The exported Collada files do not contain information about where the bone ends are.
In the SL Viewer the joints and the corresponding bone ends are just shifted
to the offset location. So for bones which have no connected children the “bone” rotation
never changes in the SL viewer.

But the most important news is: it does not matter how the end point bones are “rotated”.
And this is because apparently all scaling happens relative to the Avatar’s coordinate system.

There will doubtless be further follow-up on this at the next meeting.

Height Offset Issues

There was further discussion on the height offset issues which are being encountered  – see BUG-20013 and more recently BUG-20169 for details). This again came up for discussion, particularly the issue Aki has encountered with animations no longer functioning as expressed, as in the case of her wyvern’s hind legs (rigged using the new hind leg bones) no longer flexing correctly.

Before

Before the update: Aki’s wyvern flexes its legs to move gently up-and-down, which is the expected behaviour

aki-2

After the update: as an animation is acting on some of the bones used in calculating the wyvern’s position relative to the ground, its impact is added to the avatar’s overall position calculation, causing the entire avatar to move up and down as the height position is constantly recalculated

Vir notes that there are a number of potential causes, as previously discussed in these updates. One suggestion to try to improve things is to dial down the frequency with which the height calculation is performed (it is now being carried out more-or-less continuously), but there’s no absolute guarantee this would eliminate issues.

Part of the problem could be in the manner in which an avatar’s position relative to the ground is calculated (using a chain of bones up the left leg and then through the pelvis to the head). This has seen issues even before Bento, which has perhaps exacerbated the problem as a result of it more directly supporting quadruped / non-bipedal avatars. The problem here is that any changes to how an avatar’s height position is calculated could do more harm than good for existing avatars.

A further exacerbation with the issue is that “old” methods of fixing issues (removing / wearing a shape / avatar, etc.), no longer appear to be consistent or persistent, and a reliance on the Avatar Hover Height also isn’t always consistent (e.g. wear a shape / shoe base, etc, set hover height, then replace items and re-wear without altering Hover Height, and avatar’s height appears odd again).


Vir, Cathy Foil, Teager, and Medhue Simoni further discuss the avatar height position issue

Other Items

Updating Skeletons in AvaStar

There was some discussion / clarification on updating the skeleton in AvaStar between version (e.g. AvaStar 2 Alpha 4 to AvaStar 2 Alpha 5), and some of the problems noted with it.


Medhue Simoni, Matrice Laville and Aki Shichiroji discuss updating the skeleton in AvaStar.

Shape Update Issues

Some people have seen problems with the current (5.0.0.317597) version of the Bento viewer whereby when updating their shape others on the Bento viewer are not seeing their shape update correctly until they relog. This appears to be a baking issue, possibly the result of the Bento viewer currently not having the most recent baking service updates.

Bento Test Models

It appears the models on the Bento test page and referenced in the forum thread are not complete; then will hopefully be updated in the near future (check the dates against the models on the test page). The new models, once available should include support for all the Bento bones and (hopefully) fitted mesh support as well.

Related Links

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