A [page:Layers] object assigns an [page:Object3D] to 1 or more of 32 layers numbered `0` to `31`
- internally the layers are stored as a [link:https://en.wikipedia.org/wiki/Mask_(computing) bit mask], and by default all
Object3Ds are a member of layer 0.
This can be used to control visibility - an object must share a layer with a [page:Camera camera] to be visible when that camera's
view is rendered.
All classes that inherit from [page:Object3D] have an [page:Object3D.layers] property which is an instance of this class.
[example:webgl_layers WebGL / layers]
Create a new Layers object, with membership initially set to layer 0.
A bit mask storing which of the 32 layers this layers object is currently a member of.
layer - an integer from 0 to 31.
Remove membership of this `layer`.
layer - an integer from 0 to 31.
Add membership of this `layer`.
layer - an integer from 0 to 31.
Set membership to `layer`, and remove membership all other layers.
layers - a Layers object
Returns true if this and the passed `layers` object have at least one layer in common.
layer - an integer from 0 to 31.
Returns true if the given layer is enabled.
layer - an integer from 0 to 31.
Toggle membership of `layer`.
Add membership to all layers.
Remove membership from all layers.
[link:https://github.com/mrdoob/three.js/blob/master/src/[path].js src/[path].js]