Metareality discusses the “RedPoly” approach to mesh deformation

Note this is a 2-page article. Use the page numbers at the end of the piece to page back and forth.

Today’s Metareality podcast covers, as usual, a lot of topics, including Cloud Party and, more particularly the possible alternative approach to mesh deformation as proposed (or possibly re-proposed, given LL apparently looked at the same idea last year) by RedPoly, and which I covered in an earlier report this week.

The panel for this panel for this week’s show comprised Kimberly Winnington, aka Gianna Borgnine in-world and Karl Stiefvater, Qarl Fizz in-world, who were joined by Cyclic Gearz  and Geenz Spad.

While you can hear the broadcast in full over at Metareality, here’s a transcript of the discussion around the alternative means of mesh deformation.

[02:47] Gianna Borgnine (GB): So what is this new deformer, and how is it different? … For what I understand it works on bone definitions, is that right?

Geenz Spad

[03:07] Geenz Spad (GS): Well, basically yes, it uses several unused bones in the avatar skeleton … I guessing were used at some point to calculate the bounding box of the avatar on the server for collisions or similar. So, that’s mostly what it seems to be right now.

[03:30] Qarl Fizz (QF): I can probably add some more, but I should also specify that this is complete speculation because I haven’t had a chance to dig in … It seems like, yes, for the purposes of physics and maybe other stuff, at one point the Lindens had this approximation system put in so that when you dial your avatar sliders around, they have a basic gist of what your avatar looks like. And someone came up with the idea of using this information to do the deformation instead of the actual morphs themselves.

[04:10] GB: So, Cyclic, maybe you could answer this best: what about this is so appealing to the content creators?

[04:15] Cyclic Gearz (CG): Well, from my perspective, well, I make furniture mostly, but I still know a lot about design and stuff …  And all my designer-friends who make clothes … and part of the most difficult and annoying process is having to make five separate sizes currently, because at the moment that’s the best option for attracting the most customers – having more sizes that fit more bodies – if they have a deformer that works as is, and they do the work outside of Second Life, it reduces the workflow, it reduces the time to make new things; [it] means that they can get more stuff out and therefore more customers are happy.

[04:55] GB: So my guess is, I mean I talked to a few different people and got a few different opinions, and it was interesting to see the different sides and probably the only person I talked to … who wasn’t as thrilled about it, other than some of the developers I talked to, was Maxwell Graf, who is always looking to get rid of extra sizes, so I thought he would be excited! But for him, one of the big things was that it still felt like so much extra work because now he’s back to weight painting, which is something he was trying to get away from with Qarl’s deformer … But the thing that, as a person who does not make mesh fashions … Right now at least, you’re sort-of weight painting, but you’re painting blind, because you have to upload it to see the effects of what you did. Is that right?

Avastar in use

[06:06] CG: Sometimes; it depends on how you make your mesh. For instance, with blender you can get a plugin which you can pay for called Avastar by Gaia Clary. That is a really good way of seeing what your weight painting does and has an affect. You can also get a free burn file for Blender which is called The Avatar Workbench, also from Gaia Clary, where it has got all the bones and stuff and you can see what it’s supposed to look like. But you do sort-of have to guess … if you’re not versed in mesh or anything like that, and weight painting at all, it can be quite daunting. So from that perspective, not having to weight paint would be better for newer creator, because they’d be able to build something in blender or a different commercial program and not have to weight painting, because that is really horrible stuff! But … I do think people need to learn these skills, because the skill you learn for making 3D in Second Life can be applied in real life for big jobs … you could go into the games industry making models and stuff; but if you can’t weight paint, you’re out of luck!

[07:22] GS: Personally, I used to be an artist before I was programmer, and 3D animation was something I was always very interested in, and I definitely know the pains of having to go through and paint a variety of different vertex weights for different bones and things like that. And one thing that seemed interesting to me to the new approach to a deformer that works across all viewers that support mesh is that … you have 20-something bones you currently have to rig if you really want something that really looks good and really deforms well on most avatars with regards to just an avatar moving around; now you have all these additional bones you now have to worry about. That really seems to be the biggest drawback here. Granted, there are ways to mitigate this, and as I was saying on Monday, someone should find a better workload for this if it’s really going to be a viable solution.

[08:19] GB: Which made you really unpopular…!

[08:23] GS:  (Wryly) yes, because I’m a terrible person for suggesting something rational here, I guess!

[08:49] QF: So, I don’t know actually how this works, so may be you can help me, Geenz. So, what I said is true, right? These are like pseudo joints that the visual params modify to kinda …

[09:09] GS: … Kind-of get an idea of how big the collision capsule server-side should be – that’s what I’m guessing, you know? I could be wrong.

[09:12] QF: but you can’t visualise these in Blender at all, can you?

[09:18] GS: You pretty much have to manually add them currently.

[09:20] QF: So there’s no good way to … like Cyclic was saying, painting weights is hard, but you’re painting weights for … totally blind, right?

[09:33] GS: The worst part is here … there’s no guarantee that these will actually stick around in future versions of Second Life. I mean for all we know, after RedPoly outing it, Linden Lab may remove it in X number of months or they may keep it just because they’re afraid people began making content – and we know linden Lab’s policy on content breakage – So its either they’re going to break it now, or they’re not going to break it because people are going to make content with it. Danger of content breakage, here we go!

[10:10] GB: Well, Linden Lab is going to have to weigh-in at some point, because as it stands right now, it doesn’t deform around breasts or saddlebags or anything, so they would have to add in order to make it work right, right?

[10:23] GS: And on top of that, from what I can tell, the skeleton that’s being used is mostly just a rough approximation of the avatar itself in terms of its shape. That’s all you’re really going to need if you’re going to calculate a bounding box or a bounding capsule or something like that.

[10:41] QF: Right… you don’t notice when your avatar falls down, if his belly goes through the ground a little bit – but if his belly goes through his shirt a little bit, you do notice that; that sticks around forever … On the plus side, I’ve heard a lot of contents creators say it’s a lot more attractive; the way it changes the shapes are better …

[11:07] GB:  I’ve heard that too, and I’ve seen the video, but I know there’s a demo available now or something, but I haven’t seen that in action. So how do we know, have we seen this work – like have we tested it with some content, because that’s my one concern. Yeah, the video’s impressive, but that’s just one thing.

[11:26] QF: Well, it’s going to be really hard to make this content, right? So I don’t know; testing is going to be hard to.

Cyclic Gearz

[11:34] CG: A lot of content creators when they went to the meeting were wearing the dress. And obviously they are all different shapes and sizes, so the people wearing the dress were a good idea of how it worked visually. I don’t think it’s going to get rid of alphas or anything; we’re still going to need alphas to hide …

[11:52] QF:  Yeah, it’s going to be worse for alphas than my deformer for sure. Like I know there’s a blog today that’s talking about how we still need alphas because the stuff comes through, and this alternate deformer is going to be much worse. You can even see it in the videos, right? It’s just a rough approximation. It’s not exact at all.

[12:18] GS: Which I mean, granted, sometimes a rough approximation will work better than something that’s poly-for-poly accurate against the Second Life mesh. But really, I mean it is kind-of we have this really rough approximation that is lacking in several places or we have poly-for-poly complete and total accuracy which may cause a few unforeseen issues on some content that wasn’t properly optimised around it.

[12:45] QF: And then the other thing – sorry to change the subject – The other thing is that the new technique is a lot more efficient, computationally. It’s much easier on the rendering system. And you don’t need this giant piece of code that I wrote, which is always nice when you don’t need extra complexity like that. So – I’m going to let the community decide; I’m just going to sit out. (Laughs). You can fight it out; Geenz, I’ll buy you some boxing gloves or something…

[13:16] GS: Oh dear… this is going to be a bit of a mess. (Chuckles)

[13:23] GB: So … with the community sorting it out, the only other concern that I have – and of course, I’m always interested in the best solution, so please don’t disregard the fact that I’m still interested in the best solution – but the first thing I thought is, “Oh God, we’re never going to get a deformer”, because by the time that Linden Lab looks at whether they want to add this stuff and where they are with you and make all these decisions – like they’re not exactly known for their speed in these things. We could have two “not complete” deformers now, and I feel like that’s going to be such a distraction. So I feel like … we need to pick a direction and go that way or we’ll never have either.

[14:16] GS: Well I mean there are several different directions that can come about, but the only productive thing that would come of discussing these directions is just the sake of discussion at this point, really.


At this point Gianna had Geenz raise the subject of the Informal Content Creator’s User Group before moving on the rest of the programme. Gianna returned to Qarl’s deformer at the end.


[1:03:02] GB: What’s the status of your deformer?

[1:03:14] QF:  I guess I’m going to finish the – it’s hard to get motivated now, right? (laughs) Because now at least half the community is, “Oh! Lets go do this, let’s go do this!…”

[1:03:23] GB: (laughing) “Forget Qarl!”

[1:03:29] CG: Is there some way that the “new way” can be like – there’s some middle ground between what’s currently there and the way it’s done, or something like that? Is it possible, or is it basically one or the other?

[1:03:44] QF: I guess you could use both … but … from a technical point-of-view I would want to choose one or the other … So I guess, probably, I’ll wait for some kind of consensus to develop from the community

[1:04:08] GB: I’m still not convinced that the RedPoly is probably the best way to go. But I will trust the community as well.


At this point the discussion moved to further banter, with Gianna closing the show a little over a minute later.

Again, you can listen to the show in full here.

With thanks to Gianna Borgnine.