A Layer list is added on the left sidebar in order to classify and manage scene resources more quickly.
There will always be a default layer in the scene. Click the "+" to create a new layer. After a layer is selected, a "✔" will be displayed in front of the layer, indicating that the current layer is active, and newly added objects will belong to it. Only one layer can be active at a time. An object's current layer can be viewed and edited on the right sidebar Inspector. To change the layer of an object, simply switch in the drop-down option.
A new filter called Active Layer is added to the Object List, and it can be used to filter out objects in the current layer.
Layers support Lock and Hide functions. When a layer is locked, all objects in the layer are locked. All objects in the hidden layer will also be hidden, and the objects newly added to the layer will also be hidden immediately. In the right-click menu of a layer, click "Select all objects" to select all items in it; Click "Rename" to change the layer name; Click "Delete" to delete the current layer and all objects in it.
It should be noted that Delete button will delete the current layer and all objects in it. If you want to keep the objects in the layer, you need to right-click the layer, select all and move them to other layers before deleting the layer.