Avatar physics explained
In Second Life, avatar physics are handled by a wearable item called a physics layer.
It’s optional.
What avatar physics actually do
A physics layer controls how certain body parts move when your avatar walks, stops, or dances. Most commonly breasts, butt, belly, and sometimes thighs, depending on the body.
Without a physics layer, those parts stay static. Your avatar still moves normally, but there’s no extra movement in those areas.
Here is another link for you to check out: Amacci Physics Layers – Free
Subtle movement, not a requirement
With a physics layer worn, those areas move a little when you move. When kept light, it adds softness and weight and makes an avatar feel less rigid, especially for fuller bodies.
Most mesh bodies include a few physics layers in the folder. Maitreya, for example, gives you several options. You can wear one, tweak it in Appearance, replace it, or ignore them entirely. You can also buy physics layers made by other creators or make your own.
This is not something you need. Plenty of residents don’t use avatar physics at all.
Avatar physics and exaggerated jiggle
If you ever come across an avatar with very exaggerated jiggle, that usually isn’t just a physics layer.
There are add-ons designed to amplify movement far beyond what a physics layer does. These are not wearable layers. They are attachments, and they do use a HUD.
When add-ons come into play
These add-ons give very fine control over how breasts, butt, or thighs move. Strength, speed, direction, delay. Everything can be adjusted in real time through the HUD.
Some people love this look. Some use it for clubs, dancing, or specific styles. Others find it completely over the top.
They are optional. Entirely.
Birth is a well-known Second Life store specialising in body deformers and attachment-based jiggle add-ons. Their products are often used to create exaggerated movement and curves beyond standard physics layers. Check out their website here or teleport to their store here.
Two systems, same choice
If something looks extreme, it doesn’t mean the body is broken or badly made. It just means an add-on is being used on top of, or instead of, a physics layer.
Both systems exist. One is subtle and layer-based. The other is attachment-based and much stronger.
You don’t need either to enjoy Second Life.
