How do body deformers work?

[Jennifer Boyle]

Just curious. How does a scripted attachment change the shape of my body?

[Rowan Amore]

https://wiki.secondlife.com/wiki/Avatar_deformation

[Eddy Vortex]

I don't think it's from a script. I suspect it's made as a mesh attachment in Blender to manipulate the bones.

 

[Charalyne Blackwood]

For those who aren't certified masters of Blender or scripting, it remains light years out of reach...

[Quistess Alpha]

The overview answer is that you either

A) create an animation that translates bones, and then play it (either from inventory or via script) and assuming no other animation translates the bones, they will remain deformed until an animation reset or relog. You'd have to use a tool like Avastar or my (beta stage) animation format converter to create such an animation.

B) create a rigged mesh with bone translation enabled. This is more 'robust' against resetting skeleton and animations, and IMO a bit less janky to random fluctuation/difference between observers, but it's a bit more work to create, and not as convenient to use (only one specific deformation per attachment). An attachment of this kind can be created in blender without any special plugin (see the free shoulder deformer available from my store as an example) , although I presume Avastar would make the process a good deal easier.

[Charalyne Blackwood]

1 hour ago, Quistess Alpha said:

I presume Avastar would make the process a good deal easier.

I had Avastar 2.0. Not being a certified master of Blender made things more difficult, but the majority of issues I had were with their less than existent support. Most of the tutorials at their site remained for version 1.0. every effort I made at contacting them led me through a labyrinth of links that ultimately ended with something along the lines of "Our support desk isn't working. Try again sometime". To top it all off, I paid for the sheer joy of not really getting to use their software. Maybe I'm stupid and lack the intellect to comprehend what many have yeeted as  simple instruction, but as long as I've used Qavimator (and even some Blender) to great success for poses and builds respectively I think not.

[Nalates Urriah]

A less technical explanation for those seeing it go over their head, is to think of the human body. There is a skeleton and then all the stuff hanging on the skeleton. With an avatar there is a mathematical representation of the skeleton. The bones are made from two vertices (points with x,y,z coordinates). The ligaments that keep our RL bones together are algorithms in SL. They basically make sure that the computer can keep the end of one bone using the same x,y,z as the bone it is connected to.  And just like... the head bone is connected to the neck bone... so too SL avatar bones have a connection sequence. The sequences start at the pelvis and run out to the fingers, head, and toes. The computer figures it all out.

Our avatar in SL is optimized to simplify the number of calculations needed to move the body. So the SL avatar only has skin, no muscles or other internal stuff. The skin is an array of vertices (points with x,y,z values). There is a mathematical relationship to the bones specified for every skin vertex. Move the avatar bone and the avatar skin moves.

Deforming is done by changing the position and/or size of bones. Bones can be longer, shorter, skinnier or fatter and moved to other places.

In SL that movement or change we call deformation is made by making animations that move and position the bones or making bodies with modified SL skeletons.

AvaStar-Blender, MayaStar, 3D Max, and other modeling programs are computer programs we use to build all the relationships and put them in a form the SL system can understand.

While there is a lot of math involved it is no harder to understand than basic human anatomy. Of course if you want to get into the chemistry of what causes a muscle to contract and how that is triggered... it can get incredibly complicated. The same is true of our SL avatars.

[Rick Nightingale]

On 9/10/2022 at 9:18 PM, Charalyne Blackwood said:

I had Avastar 2.0. Not being a certified master of Blender made things more difficult, but the majority of issues I had were with their less than existent support.

I'm very far from an expert in either Blender or Avastar - purely an amateur who uses them maybe once or twice a year and forgets how to drive the things in-between.

I've found the support for Avastar on their Discord server to be superb and invaluable though, both from other users and the staff. If you need help, that's the place to go I suspect. I seem to recall some new videos were published just some weeks ago too.

Edited September 14, 2022 by Rick Daylight

[Charalyne Blackwood]

11 minutes ago, Rick Daylight said:

I'm very far from an expert in either Blender or Avastar - purely an amateur who uses them maybe once or twice a year and forgets how to drive the things in-between.

I've found the support for Avastar on their Discord server to be superb and invaluable though, both from other users and the staff. If you need help, that's the place to go I suspect. I seem to recall some new videos were published just some weeks ago too.

Back when I tried their discord server, the very few answers I got were largely technical jargon targeted at people with PhD's in computer sciences. This was 2 years ago and I've since updated to Blender 3.2. I'm not about to drop money for an alleged update for Avastar to match it.