Category: SL Tech

The following notes are taken from the Content Creation User Group meeting, held on  Thursday, June 29th, 2017 at 1:00pm SLT at the the Hippotropolis Camp Fire Circle. The meeting is chaired by Vir Linden, and agenda notes, etc, are usually available on the Content Creation User Group wiki page.

Medhue Simoni live streamed the meeting via his You Tube channel, and I’ve embedded the video at the end of this article. Time stamps in the text below reference this video. Note, however, that items are presented by topic, not necessarily in chronological order. Audio extracts are also provided, but please not these may have been comprised to just the core points of discussion / statements (while avoiding any loss of context).

Rigging To Attachment Points

[1:11-8:45] There has been some discussion around this for the last couple of meetings. In essence, rigging to attachment points was used by some content creators in the past to overcome a shortage of bones. With Bento, it was decided that rigging to attachment points should not be supported in new uploads, but would still be allowed for older meshes using it, to avoid content breakage. However, it now turns out that there is a conflict between the simulator (which allows rigging to attachment points) and the viewer (which shouldn’t allow mesh rigged to attachment point to be uploaded – although some TPVs still do, by accident or design).

Vir is still looking into this to determine how best to handle things going forward. However, as it has been pointed out that there is legacy content which cannot be easily updated if uploads of meshes rigged to attachment points is blocked, and clothing cannot be made for mesh bodies using rigged attachment points, His current feeling is that the simulator behaviour will likely not be changed and that the viewer  – based on a JIRA he has raised – will be updated to be consistent with the simulator’s rules, although he made a request that new avatars are not made with meshes rigged to attachment points.

Note: the discussion on the video includes references to Firestorm (version 5.0.1 onwards) no longer accepting uploads for mesh rigged to attachment points due to an accidental breakage (the fix didn’t make the cut for the 5.0.7 release).

Animated Objects

Attachment Points on Animated Objects

[10:29-14:21] Animated objects will have attachment points as they use the avatar skeleton. However, the following should be kept in mind:

• In relation to rigging to attachment points (above) – this should work for animated objects (so this could allow existing avatars rigged to attachment points and volume bones to be converted to animated objects, for example)
• The Lab is undecided on including attachment points at this point in time in order to allow items to be attached to animated objects (or animated objects to one another). They are simply there as a part of the avatar skeleton.

General Status

[39:59-41:30] The animated objects (aka “Animesh”) project is progressing. Still no ETA on a project viewer. Vir is still working on getting the avatar skeleton to work with linksets of multiple meshes making an object.  Most of this is working, although the graphics pipeline still gets upset in places if changing objects from animated to static or vice versa at the wrong time.

Still to be done is evaluating the land impact of animated objects, deciding whether or not to implement support of attachment points now or in the future.

Given that objects already have a land impact, the current thinking is that when converted to animated objects, they will likely incur an addition LI overhead – although what this will be can only be determined in time. Hence, for the project viewer, once available, it may be an arbitrary figure, subject to adjustment.

Bakes on Mesh

[17:28-18:10] Anchor linden is making “good progress” on updating the Baking Service to support increased texture resolutions (512×512 to 1024×1024). Once this work is completed, the next step is to run performance testing on the baking service to assess how well it can support the increased resolution, and whether any additional hardware, etc., might be required in support of the increased loads.

Other Items

“Crazy Bone Scaling Animation”

[9:00-10:05] During the week #25 meeting, a bone scaling animation was demonstrated which could rescale an avatar  to huge proportions, as if it were being “blown up” / inflated. Vir looked at this and believes it is the result of storing animations in a way that’s “not normalised” and which are not being handle correctly for scaling. So while useful in the way it currently performs, the technique isn’t useful for accurately rescaling the avatar skeleton.

Hires Proxy Mesh Rigging

[16:33-16:49] This came out of the last meeting, and Beq Janus is working on a design outline for it, covering how it could supported in-world and protect mesh body creators’ intellectual property at the same time. She plans to offer the document via Google Docs, and those wishing to read it and provide feedback should e-mail her at beq.janus-at-phoenixviewer.com for access.

Mesh Uploader and LOD Options

[20:35-43:00] A suggestion was put forward to change the Level of Detail (LOD) buttons on the mesh uploader from the current “Generate” default to “Load from File” in an attempt to encourage creators to make their own, efficient, LOD files, rather than relying on the auto generation process – which is not always as efficient as custom LOD files.

Feedback was that changing the buttons would not help, but could encourage people simply to generate a single high LOD file and use that (a problem already evident when custom LOD files are used). An alternative suggestion was to remove the ability to adjust the LOD auto-generation process (so no spinners on the uploader) – so unless creators supply their own LOD files, they have to accept whatever the uploader generates for each level.

The core of the discussion in voice is below, but please refer to the video to hear it in full.

This led to a lengthy (primarily text) discussion about how to encourage creators to use their own sensible and custom LODs, which is interspersed with other topics. Some of the idea offered by users at the meeting were:

• Making customer LOD uploads cheaper than if generating them through the uploader
• Offering similar incentives to encourage creators reduce their high-end poly counts and not fudge their low-end LODs
• Improving the preview option in the uploader to better represent LOD sampling
• Adding a field on the marketplace similar to the Land Impact one but for Display Weight on worn meshes (on the basis that a high display weight can be indicative of poor LOD usage), and in theory encourage creators to be more efficient in their use / provision of LOD files
• Have a render meta mode like physics, that shows the quality of the LODs as a colour map (e.g. look at the volumetric relationship between the LODs on the basis that a good LOD should hold volume)
• Instructional videos from Torley – although Medhue Simoni has a 3-part series on LODs: Part 1, Part 2, Part 3.

In Brief

• [14:52-15:36] The link on the SL wiki Rigging Fitted Mesh page to download the avatar skeleton is currently broken.
• [19:04-20:22] Inverse Kinematics via LSL function with global position – this has been suggested a number of times. While noting it would be useful (it might, for example, enable an animation to make it appear as if an avatar is opening a door when standing before it), Vir stated it has not received in-depth thought at the Lab in terms of being implemented or how it would work, given the server currently doesn’t know where the joints in an avatar are, so it introduces a level of complexity as to how things would be handled.
• As most people know, initially accessing Aditi is a case of submitting a support ticket. Inventory is now merged between Agni (the Main grid) and Aditi around 24 hours after initially logging-in to the latter (a merge process is run every day for all accounts which have been logged into since the last run). However, it now appears that changing your SL password can break your Aditi access, requiring a further support ticket.
• [43:09-end] Discussion on copybotting, policies, banning, etc., which threads through to the end of the meeting, and split between Voice and chat.

The majority of the following notes are taken from the Content Creation User Group meeting, held on  Thursday, June 22nd , 2017 at 1:00pm SLT at the the Hippotropolis Camp Fire Circle. The meeting is chaired by Vir Linden, and agenda notes, etc, are usually available on the Content Creation User Group wiki page.

Audio extracts are provided within the text, covering the core project LL has in hand. Please note, however, that comments are not necessarily presented in the chronological order in which they were discussed in the meeting, but are ordered by subject matter.

Server Deployments Week 25 – Recap

As always, please refer to the server deployment thread for the latest updates.

• On Tuesday, June 20th, the Main (SLS) channel was updated with a new server maintenance package (#17.06.12.327066), containing fixes to help with the caps (capabilities) router (see here for details).
• On Wednesday, June 21st, the RC channels were updated as follows:
  • BlueSteel and LeTigre should receive the same server maintenance package (#17.06.19.327206) containing internal fixes
  • Magnum should receive a server maintenance package (#17.06.19.327192) intended to fix BUG-100830 (“HTTP_CUSTOM_HEADER no longer works on RC 17.06.13.327111”) and BUG-100831 (“Lelutka Simone bento head spits a script error when attached on 17.06.13.327111 regions (Magnum & Cake)”).

Animated Objects

Vir has been trying to get animated objects using the avatar skeleton to scale in a reasonable way and that linksets are correctly referencing the same skeleton, and things are handled corrected when they are attached or detached. He’d also be interested in hearing from makers of the “current generation” of pets on how they work – how do they maintain ground contact, how they follow along, how the physics is getting managed, so that he can look into trying to make animated mesh objects operate in a compatible manner.

So, if you are a pet maker and can help Vir in this, please either attend the Content Creation User Group meetings, or contact him directly.

Attaching Animated Objects to Avatars and Avatars to Animated Objects

One of the popular aspects of pets today is the ability to attach them to an avatar (so you can carry them, have them sitting on your shoulder, etc), and this is seen as a potentially important aspect of animated mesh. However attempting to do so does present issues, as it would mean linking two avatar skeletons in some manner, something that is not currently possible. While there are some potential ways this could be done, it could add considerable overhead to the existing project, and also brings potential challenges with it – such as ensuring an attached skeleton is correctly oriented, determining the potential performance hit, etc..

Similarly, BUG-100864 suggests a means of going the other way – linking an avatar to an animated object – such as being able to walk up to a free-roaming horse on a region and being able to mount it and ride it, for example. However, this also raises some of the same concerns.

While not ruling either out, Vir is focused on bringing forward a relatively basic means of animating mesh objects using the avatar skeleton, one which can offer a series of potential uses whiles conceivably allowing existing mesh creations (such as pets) to easily be converted to use it. As such, he sees it as a foundation project, which can then be expanded to incorporate other capabilities in the future, rather than trying to pack everything into a single project which could run the risk of very long development times or becoming overly complicated with all it is trying to achieve right from the start.

Baked Textures on Mesh

Work is still focused on the baking service infrastructure updates required to support baking textures on mesh avatars. These are quite extensive, involving changes to the underpinning tools, the servers (including updating Linux), and so on.

Rigging To Attachment Points

There has been some confusion of late as to whether rigging to attachment points is allowed or not. From the Lab’s perspective, it is not allowed for uploaded since the introduction of Bento, but should still work for legacy items. However, what appears to be a server-side glitch in the last couple of weeks seems to have exacerbated the confusion.

Vir’s recommended rule-of-thumb for TPVs to test against the Lab’s official viewer and ensure behaviours match, otherwise confusion could occur down the road once the current glitches have been corrected. To help with matter, he’s going to refresh his mind on what limitations are enforced server-side, and hopefully bring a list of them to the next meeting to help TPVs ensure they are following the requirements in order to avoid future problems.

Other Items

Mesh Body Dev Kits / Clothing Making / “Standardised” Mesh Avatar

This topic took up the core part of the meeting, and as such, the following is an attempt to precis the core points into a readable summary

At the moment, all mesh bodies in Second Life are unique to their creator, utilising their own core shapes and skin weightings, which have a considerable amount of IP bound up in them. Because there is no available “standardised” mesh model available in Second Life, it means that the body creators need to provide developer kits to mesh clothing and attachment makers, which include this core information –  skin weights (in Blend or Maya or DAE or OBJ files) for rigging clothing and the shapes, which potentially makes it very easy for someone to create their own avatar bodies.

To try to reduce this risk, mesh body makers tend to have license agreements clothing makers are required to agree to, and by sometimes limiting who may or may not be deemed eligible to obtain such a kit.   This has  caused some friction / frustration in the cloth making community.

One suggestion put forward to help reduce fears on the part of mesh avatar creators and allow clothing makers more readily support avatar body brands, was that avatar makers should perhaps consider offering only the body shape to clothing makers – and then offer a fee-based rigging service to clothing makers. This would remove the need for avatar makers to give out their skin weight files, offer them a revenue stream and allow clothing makers more equitably create clothing for the more popular mesh bodies.

While there are no projects on the roadmap aimed at the SL avatar system, two other ideas were put forward which Vir agreed, could be worth consideration down the road:

• One is a suggestion that LL look to emulate the ability in Maya and Blender to copy skin weights from an avatar model to an item of mesh clothing by running an algorithm to match the weighting from the avatar to the nearest vertices in the clothing. This would allow the clothing to fit almost any mesh body “automatically”, removing the need for clothing makers to specific weight their clothing to each of the mesh bodies they wish to support.
• The development of a news “SL mesh avatar” designed to operate alongside the existing system avatar (so no content breakage for those preferring to continue using the current system avatar). If this avatar had a sufficient density of vertices, it offers two potential uses:
  • Mesh body makers could use its weightings with their custom shapes to produce individually unique mesh bodies, but which all have a “standardised” set of skin weights, reducing the amount of work involved in creating them (or they could continue to use their own custom skin weights if they wished
  • It could offer clothing makers a single source of skin weights for clothing, simplifying clothing making, which – if combined with the vertices matching algorithm mentioned above – would help ensure the clothing “fits” custom weighted mesh bodies.

The vertices matching algorithm idea might be the more difficult of these two ideas to implement – were either to be considered. However, the development of a mesh avatar that could exist alongside the system avatar could have a lot of merit and help “standardise” the more technical aspects of mesh avatars without impacting their individual shape / look.

Further, as mesh objects can support multiple UV sets, it would be possible for such an avatar to use the legacy UV map use to define the texture spaces on the three parts of the system avatar (thus allowing it to use existing skins, etc), or it could support more “advanced” UV maps (so skin creators could finally design skins with two arms, rather than having the one arm “mirrored” on the avatar, as is currently the case.

Why isn’t Scaling Bones by Animations Allowed?

Scaling bones using animations has never been supported in SL, although Vir isn’t clear on why (and pseudo bone scaling via animations has been possible through attachment point scaling or animating the point positions). However, one of the things that makes designing avatars harder is multiple ways to manipulation and aspect of a bone, because of the potential for conflicts. An example of this is bone translations, which can be affected by both animations and the shape sliders, and so can cause issues.

However, during the Bento project, the advantages of allowing translations through animations was such that the Lab opted to permit it, even allowing for the potential for issues. As scaling bones through animations could bring about a similar level of possible complexity to avatar design (as bones can obviously be scaled via the sliders, this could be the reason scaling bones via animations hasn’t been supported. Currently, this is unlikely to change, if for no other reason it would require a change to the animation format, which currently has no means to interpret bone scaling.