The Environment can quickly fill up with a large number of objects. To keep things organized, you can assign objects to different display levels, referred to as layers. Think of layers as being different, partial views of the overall Environment. You can easily connect objects between different layers.
The distribution of objects across different layers has no effect on their functionality—it’s simply a better way to organize objects. The name of the current layer is shown in the Layer pop-up menu.
The position and existence of the first two layers—All Objects and Global Objects—is protected, and they cannot be deleted.
All Objects: This layer displays all objects in the Environment. The objects in this layer are normally shown as a list. To switch to the selected object’s layer, choose Options > Go to Layer of Object in the Environment menu bar.
Global Objects: In this layer, you can place objects that you want to be visible in all layers. These objects appear at the same position in all layers. Try to assign as few objects as possible to this layer, due to the onscreen clutter that global objects can create.