Category: Content Creation User Group

The following notes and audio were taken from the weekly Bento User Group meeting, held on Thursday, February 4th at 13:00 SLT on Aditi.  For details on each meeting and the location, please refer to the Bento User Group wiki page.

Bent Bones Survey

The Bento bones survey is now closed. Vir presented an overview of the results during the meeting and subsequently published the results on the Bento forum thread. Some 54 responses were received, which he has been analysing.

Additional Bone Groups

In terms of the questions on the 7 proposed joints or sets of joints, no clear winner emerged, with the average ranking for the seven coming between 3.18 and 4.32 (lower being better). Additional wing bones fairing the poorest of all, with additional facial bones and / or additional ear bones fairing the best.

Since the survey results were published, Gaia Clary has pointed out that it did not include the proposal for a group of three additional bones for the centre lip and forehead, which have been viewed as being important for natural facial expressions such as decent smiles. The exclusion might explain why one of the proposals was effectively listed twice in the survey (options 1 and 3). There’s currently no indication as to how group indicated by Gaia might now be considered.

Written Feedback

The open questions asking for written feedback did produce a clear winner: more tails / limbs or more tail joints, with most of the respondents to the questions (18 and 14 respectively) citing a desire to support hexapods, centaurs, or other multi-limbed creatures.

The requests for additional tail  / limb bones saw Vir ask for further feedback on matters to make sure he was grasping the reasons for the requests correctly – notably that people would be using bone translations for the additional limbs, allowing the spine to act as an initial anchor point for the bones, which then could be translated into their preferred positions.

Wing Roots, Pelvis Bones and Options

A contributing factor for wing root bones not proving popular is because they were originally included to compensate for the fact that Bento initially didn’t support bone translation, only rotation; thus additional bones were required to assist with achieve more natural wing, etc., movement. Now that bone translation is considered part of Bento, the need for multiple extra wing root bones is removed, with the result that some could be replaced by more meaningful bones used elsewhere.

A set of bones which came in for particular discussion were extra pelvic bones, with Vir asking for clarification on the benefits would be in having them. My apologies for the extract from this part of the meeting, a mis-click on my part meant that part of the conversation in which Teager explained how it would allow for easier compatibility with existing animations so that, for example a centaur might be able to make use of existing upper body animations for arm / head movements wasn’t cleanly recorded and so is not a part of the extract.

Bone Constraints

When  discussing working with initial versions of the Bento skeleton and developing the Avastar face rig to help in producing facial animations in early January, Gaia Clary raised the subject of utilising bone constraints as a means of adding a further level of control for bone movement within the avatar.

This would allow root bones to effectively be paired such that the movement of one is controlled / constrained by the movement of another (see this comment from Television as well).  This is a common approach to animation, and greatly eases the animation process, and if completely followed through, could add enormous flexibility in what could be done with the avatar skeleton, as Gaia notes:

If constraints can be implemented in general, then this concept could be generalized to work for all limbs, then users can for example constrain the root bones of the legs, arms, wings and tail to mSpine and create a 7 legged creature that can be animated without adding odd rules to the animation.

Thinking even further, if location constraints were allowed, then this idea allows to constrain any limb to any bone. Wings could then be constrained to eye brows for antennas, tail(s) could be constrained to chest for 4 winged creatures, etc.

The problem here is how to implement such a system of constraints within Second Life. While there are animation programmes and system which do allow for constraining bone movement, it’s not clear if they all utilised a standardise approach, or whether then could be easily replicated within Second Life, or what the overhead involved would be in trying to develop the means for the platform to support bone constraints.

Given this, and while the ideally has not been ruled out for future evaluation, adding such a capability at this put in time for Bento has been seen as being out-of-scope for this phase of the project.

Continue reading “Project Bento User Group update 4 with audio” →

The following notes and audio were taken from the weekly Bento User Group meeting, held on Aditi every Thursday at 13:00 SLT.

For details on each meeting and the location, please refer to the Bento User Group wiki page.

Bone Survey

The  Bento Bone Survey, intended to gauge the level of interest in various bone proposals for the Bento skeleton is now available. The Lab is requesting animators and content creators with a vested interest in Project Bento to rank the bone proposals to help with prioritising which additional bones people would like to see added to the Second Life avatar skeleton as a part of the Bento work.

If you are an animator / content creator with such an interest, and you haven’t already completed the survey, please ensure you do so as soon as possible, as it is likely to be closed on or shortly after Monday, February 1st.

The Lab notes they do not currently know how many additional bones we can reasonably add, or whether some of the associated bugs can be fixed.

Drax Files Filming

The final session of Bento filming for The Drax Files World Makers will take place on Monday,  February 1st at 11:00 SLT at the Bento Island region on Aditi. All those with an avatar developed using the Bento avatar skeleton extensions are invited to attend.

Deformed Avatars

Distortions with Altitude

Cathy Foil has been examining issues with deformations at altitude occurring in avatars using the Bento  skeleton. She first noticed the issue whilst Bento was in closed session and reported details to the Lab. However, efforts at pinning down he precise cause have been hampered up until recently by not being able to gather sufficient data from the skeleton and a lack of detailed comparisons between the effects as seen on various viewers utilising the Bento code.

Cathy has been addressing this using the most recent release of the Bento project viewer, and carrying out further detailed tests at various altitudes to document the severity of the issues more fully (they tend become noticeable at altitudes over 1000 metres). She has now passed her latest findings over to the Lab for their investigations.

“Squished” Avatars”

Cathy has also been investigating the issue of avatars deforming as a result of using a mesh uploaded with different joint positions. This tend to result in avatars looking “squished” or otherwise deformed.

As she uses Maya, part of her investigations point towards possible issues with versions of the plug-ins used by Maya to convert .FBX format mesh files to .Collada .DAE (the format used by SL). Whether or not the plug-ins are the cause isn’t definitive as a cause, but may be a contributing factor. As Vir noted in the meeting, if this is the case, then it is unlikely the Lab can do much about it, but those using Maya affected by the issue may need to check the version of the Collada plug-in they are using, and make sure they have the most recent to see if this clears the problem.

If it is more of an issue with the mesh uploader, however (because the Lab have missed something, for example), then obviously, there is more of a chance of the Lab taking remedial action.

Cathy Foil discusses her investigations into avatar deformations at altitude

Joint Reset Issues

A long-term problem with Bento has been it is easy for joints to get into the wrong state and / or position when animating an avatar using the Bento skeleton extensions. It’s often not clear why this happens when it occurs, which can be somewhat random. Vir has started collecting data on the issue. Nothing definitive has been identified in terms of a cause or causes, but Vir will be continuing to work on the issue.

“First Frame” Animation / Default Avatar Pose Issues

Another issue which has been noted is that of a first frame of an animation begin played three times as the animation is run, and which may be connected to default avatar poses within Second Life. This is a fairly “old” bug, dating back as far as 2007 (see BUG-11194), and which seems to be more prevalent with Bento as a result of bones being used differently (e.g. arm bones being used as forelegs, etc).

Medhue Simoni demonstrated the issue using two of has non-human avatars, an elephant and a wolf, which saw both attempt to cross their front legs (as a human might try to fold their arms) when transitioning between animations.

A lengthy discussion followed on the problem, which might also involve a number of other issues, including poses “baked” into the default avatar skeleton, possible race conditions between the viewer and the server, and issues with animation prioritisation.

It may also be related to how Second Life handles transitions between animations (referred to as animations “easing out” and “easing in” when moving from one to another), which has had other problems reported against it as well – see also BUG-11122, for example.

As indicated in Vir’s comment on BUG-11194, and noted in the discussion, there is some initial concern from the Lab that if the playing in triplicate was an intentional change – and one made well before most developers currently at the Lab having joined the company – or if it requires symmetrical changes on both the viewer and the server, it might result in some content breakage without detailed analysis, although Vir has now started digging into the code to have a look.

Continue reading “Project Bento User Group update 3 with audio” →

The second public user group meeting for Project Bento took place on Thursday, January 14th 2016, continuing discussions on the new avatar skeleton extensions for Second Life. The following is intended to provide a summary of the discussion, together with audio excerpts from the meeting. It is not, however, intended to present a full transcript.

Additional / Alternative Bones and Experimental Region

The experimental region for those wishing to try additional / alternative bones (see my report from the first Bento public UG meeting), is now available on Aditi at BentoExperimental1. It had been misbehaving when first set-up, but is now thought to be running smoothly. 

One concern among content creators who are already working on Bento is the potential for additional / alternative bones to be disruptive, that has they are added, it will break content being used for ongoing testing of Bento, particularly for those working on complex, multi-limbed avatars.

Vir pointed out that while the Lab don’t want to necessarily add to the workload in testing new bones, it’s better to look at possible additions / alternatives sooner rather than later, and accept test content may break if charges are to be made in the near future as a part of developing the project.

He also pointed out that so far, the focus on additional / alternative bones has been on the face, which shouldn’t have any impact on those working with the new wing bones, etc. Although that said, there is no limitation on proposing additional bones for wings, legs, etc., even if they do prove a little disruptive at this point in time.

End dates and Selecting New Bones

Currently, the Lab hasn’t determined any date by which proposals for additional / alternative bones must be made, or the process by which any of the proposals might be adopted. However, creators are encouraged to use the experimental region to develop models as demonstrations sooner rather than later.

While it is not 100% certain, given there is currently no clear consensus as to what additional / alternative bones might be seen as a priority among those proposing them, the Lab is considering making any potential selection the matter of a poll at some point in the future, and make any determination based on that.

Vir also indicated that ideally, the Lab would like to make as few further changes to the skeleton as possible, and so may opt to add additional bones as a single pass in the viewer, rather than gradually adding them (which might also cause problems when testing, due to the repeated risk of breaking test models as noted above).  Either way, the code will be stabilised well before any attempt is made to move Bento to the main grid, in order to ensure that people have adequate time to test things and to allow TPVs sufficient lead-time to integrate the Bento code into their offerings so that they can support it when it is deployed.

IK Bone Issues

A problem has been noted within the skeleton between the new toe bones and the IK (inverse kinematics) bones which connect the avatar physically to the world. The latter are focused on the foot bone in the avatar skeleton, with the result that when the new toes bones are used to animate the avatar (as might be the case with digitgrade legs), a conflict with the IK bones can occur, causing the animation to go awry. It doesn’t happen all the time, but when it does, it is very noticeable.

Exactly what can be done to deal with this is open to question; Vir’s initial thoughts were to consider changing the logic so that IK bones are focused on the toe, rather than the foot. Alternatively, Oz suggested adding a new flag which would allow a mesh to indicate it does not want a joint manipulated by IK, and idea which was seen by some creators as offering greater potential for use.

To help the Lab better understand issues and gain a thorough insight what might be required in order to address issues where they can, a request was once again put forward for very concise in-world examples and models.

Both Oz and Vir concurred that any large-scale alternations to the IK chain, such as extending it to include the new bones is unlikely, due to the risk of breakage with existing content on  the main grid and due to the additional overheads it will place on Bento in terms of testing, lead times, etc.

Continue reading “Project Bento User Group update 2 with audio” →