UNDER THE HOOD
AVATAR SHAPE & ANIMATION
Presented info applies strictly to correlation of avatar shape and animation, not to other aspects of SL
Subject of Animation…
…are bones and bones only.
The system of bones we are using for animating is called “skeleton”… duh! Or rig, mostly for some other purposes, but i love old fashion 'skeleton'!
The skeleton (rig) in Second Life is invisible unless you make it visible from Developer → Render Metadata → Joints (may vary depending on viewer).
Nowadays, it is all a bit of a mess if you don’t know where to look, as someone had the brilliant idea to mix two different visual representations of bones - boxes and sticks… it is anything but useful anyway!
But if you are curious, go ahead and check it, or refer to the image below.
See those tiny lines and dots? That is what we are dealing with. Not such-and-such body mesh brand. This! It is the system set of bones that carries data from all areas: your body and face shape, your mesh bodies and heads, your rigged clothes, and - animation. Too much for one tiny, fragile set of bones.
As part of the process of creating your ideal body shape, you are manipulating those bones, their scale and position to be precise. By changing slider values for your shoulders and hips, you are also affecting where your arms and legs are. You are playing with body proportions. The size of your avatar actually doesn’t affect what will happen with animations after, as much as body proportions do.
It is creative freedom. It gives that unique variety of sizes and shapes SL carries. But that freedom comes with a price: animations are not fitted like mesh. There is no system in SL that will align every animation to every body shape. We are working with absolute numbers, and there is nothing flexible in animation.
So, if I rotate your arm by 45 degrees, it will rotate by 45 degrees, regardless of where your, let’s say, leg is. Period.
Whether that arm will end up inside your body, or that drink inside your head, is not up to the animation - it is up to your body shape.
And no, you didn’t do anything wrong. The animator didn’t do anything wrong. The lack of a system bridge between these two important parts of SL is something that is hard to ever fully solve. We all have to accept things as they are and get used to imperfections.
Impact of Hip Width on Legs Position
Impact of Shoulder Width on Arms Position
And let’s settle something once and for all: there is no such thing as a “default shape”. There is no such thing as a “standard” body shape. There is only a personally preferred body shape. As long as we have body sliders in SL and freedom to express ourselves in that way, don’t fall for those terms. Some creators will push the idea of “standard” or “default” for their own purposes. From an animator’s position, I would have far less to explain if that were the case, but it is not.
And that is the hill I will die on.
For those exact reasons, female and male animations are mostly not interchangeable. Yes, you can use some female animations on a male with a more boyish constitution, and you can use male animations on a female with a strong, muscular constitution… but it’s usually not a good idea. Female and male shapes have more structural differences than you may notice at first glance, so please avoid mixing genders when it comes to animation.