Project Bento User Group update 22 with audio

Project Bento – extending the SL avatar skeleton

Project Bento – extending the SL avatar skeleton

Updated: animation of collision volumes is being added – section updated section below.

The following notes and audio were taken from the weekly Bento User Group meeting, held on Thursday, August 11th at 13:00 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.

Time Frame for Promotion to Release Candidate Status

Some at the Lab are keen to see Bento move forward and reach a larger audience of content creators (although there is currently no reason why creators cannot get involved now and attend meetings, help with feedback, etc). Inevitably, this means promoting the Bento viewer to release candidate status, and doing so some time in the next two weeks has been mooted.

Given the number of issues currently being investigated, not all of which are viewer-specific (see below), but for which fixes may yet have an impact on the viewer, this would seem to be a somewhat ambitious time frame.

Viewer Issues

Work at the Lab is focusing on a batch of issues for which bug reports have been raised, including:

  • Several relating to joint positions:
    • BUG-37546 [BENTO] facial bone joint offset issues – which has been the subject of recent Bento updates in this blog
    • BUG-37591 [BENTO] New import of a non-human rigged mesh is deformed
    • BUG-37633 Bento – Custom joint positions and Reset Skeleton not matching
  • Avatar height calculation issues:
    • BUG-20013 [Bento] When wearing a Bento avatar, observers see your hover height lower than you see it yourself
    • BUG-20169 [ BENTO ] Z-Offset not applying correctly & camera tied to Z-offset
  • Eye scaling problems (referenced via SL-433, an LL internal bug report)

The eye scaling issue, the result of the scaling within the viewer for mesh eyes being different to the expected system eye size, has been corrected, and will be one of the fixes released with the next viewer update, although existing models may need tweaking as a result a test carried out during the meeting using an early build of the next project viewer iteration suggested that there are still issues, and Matrice believes part of the problem might be within AvaStar.

Facial Bones Issues / Distortions

At least some of the facial bones issues appear to lie with AvaStar exports, which Matrice and Gaia are trying to rectify. Gaia offers an explanation for the problem in the Bento forum thread. Matrice further notes that there is a discrepancy between the restpose and the SL default pose; in Blender there is no easy way to define the absolute SL restpose in order to add bind pose information on top of it, leading to the wrong information (or even a lack of information) being exported to the Collada files.

Matrice is working on improving things in AvaStar, but the work is taking time and effort. Gaia has offered a detailed explanation of joint preparation on the Machinimatrix website as a workaround as they continue to redefine and improve their workflow, and offers a brief summary of the approach through the forum thread. The workaround isn’t seen as optimal at the moment, but the hope is that once the work on AvatStar has been completed, the workflow should be more straightforward and transparent.

Machinimatrix have produced a workflow process to handle the correct placement of facial bones. This is not intended to be the finished means of doing so, but is offered to counter issues currently being encountered

Machinimatrix have produced a workflow process to handle the correct placement of facial bones. This is not intended to be the finished means of doing so, but is offered to counter issues currently being encountered

Some questions were asked on whether it was an AvaStar issue rather than something inherent in the viewer, prompting Vir to comment that given the viewer handles joint positions in a model and joint positions in an animation pretty similarly, it’s hard to see how the viewer could be at fault, but acknowledged the only way to be sure of this is test once AvaStar have reasonable confidence they have corrected the issues they have identified.

Later in the meeting, Matrice offered a further explanation of the Belender / AvaStar issue,  also pointing to the explanatory document on joint preparation, again noting that things are very much a work-in-progress on trying to fix things.

During the meeting, Medhue Simoni tried the recommended approach given in the documentation and found it did resolve all of his facial deformation issues, other than with his eyes, which as noted above, may require further viewer-side tweaks and additional work within AvaStar, as Matrice commented.

Avatar Height Position Issues

The camera issue which can be encountered as a part of the avatar height calculation issue

The camera issue which can be encountered as a part of the avatar height calculation issue

I’ve covered this at length in past updates (see update #21 and update #19 for more). The Lab hasn’t progressed any further with a fix, but may look to alter the frequency of updates to see if this helps.

The problem is viewed as being rooted in animating one of the bones used in the calculations for determining the avatar’s height relative to the ground (left leg, up through the pelvis and head), so the solution may ultimately be down to alternative means of animating movement without touching something like the pelvis bone – something which may not be possible when trying to replica certain types of natural movement.

Rigs Modifying Collision Volumes

There have been recent reports of people encountering problems with Bento rigs which modify collision volumes. As Vir explains in the meeting, it’s not something that the Lab planned on supporting, nor did it come up during the original Bento development meetings when rigging to attachment points was discussed, so no effort has been put into making sure it works at all. Vir is now looking at the issue, but whether the Lab will support it is questionable at this point in time; however, the focus at the moment is to more fully understand the impact.

Update, August 12th: Whirly Fizzle pointed me to a viewer repository containing an update to support the animation of collision volumes, to avoid breaking existing content.

Other Items

Slider / Bone Spreadsheet

Aki Shichiroji has been putting together a spreadsheet of all the slider settings and how they affect the Bento avatar bones and geometry. It is very much a work in progress, given things are still in a state of flux, and Aki notes she is aware that there is missing information (she has yet to run through the avatar.LAD file and the avatar skeleton file). However. she has made the spreadsheet available through Google Docs, and welcomes constructive feedback from content creators (which should be addressed to her, I’m not sure if Aki reads this blog!).

Maya / MyaStar And Custom Joint Positions

Following the discussion of Blender / AvaStar and custom joints, Cathy Foil provided some additional information to help Maya users with MayaStar.

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