Layers

Layers are virtual levels in a drawing, analogous to acetate tabs (overlays) in traditional drafting. Layers enable you to sort objects in your drawing by type, by creation order, or by any criteria that suits the way you work. You can also use layers to protect certain objects from being edited or deleted.

Note: Layers are not related to how objects are stacked in relation to their order of creation. If you change an object's layer, it does not affect its position in the object stack.

Setting Up Layers

There are two primary ways of creating and editing layers. With regard to layers you can do essentially operations with either.Open the Layer manager by selecting Format / Layers, or by clicking the Layers icon on the toolbar.
This dialog is used to create layers, to assign properties to each layer, and to organize layers. It is divided into two frames. The first frame show the tree containing the layer filter, and layer templates. The second frame show the layers. controlled or derive from the item selected in the tree. The top node of the tree controls and shows all layers in the drawing.

Layer 0 is the default layer, and all objects are placed here unless otherwise specified, or unless another layer is created and made active. Layer $CONSTRUCTION is created when construction geometry is created (see Construction Geometry). Neither of these default layers can be deleted, but you can change their properties.
Layer Set: See Layer Sets
Columns in Layers window: Use the horizontal scroll bar to see all columns. You can sort the list by clicking on any column heading; the list will be sorted according to the selected parameter. 
Visibility (eye icon): Check to make objects on the layer visible.
Read-only (lock icon): Check to make the layer read-only, so that objects cannot be edited or deleted. You can add objects to a read-only layer via the Layer drop-down list located on the property toolbar.
Color: Click on the the color box to open the color dialog, then select a color - The default color is black. Objects will have the layer color if their color is set to By Layer.
Style: Select the line style from the drop-down list and double-click to set it. Objects will have the layer style if their style is set to By Layer. Order: Determines the order in which layers are drawn. Order can be used to place certain categories of objects in front of others; objects drawn on higher layers will be "over" those on lower layers. The order numbers are initially set to zero. Layers that have the same order number are sorted alphanumerically. The highest layer number is 32767.

Warning: The Draw Order commands will not function as you expect if objects are on different layers and the layers have different Order values.

Pen Width: Sets the line width. Objects will have the layer width if their width is set to By Layer.
Print Style: Specifies the Print Style to be used by objects on that layer. Print Style Options.
VP Columns in Layers window: In addition to the main columns in the Layers window there are five columns with a VP prefix. VP stands for Viewport, and these columns are use to control how objects will appear within a selected viewport.

The columns are: VP Visible, VP Color, VP Line Style, Pen Width, Print Style.The VP columns operate in the same way as the main columns, except the settings effect on selected viewports.To use the VP column settings:

1. Open the Layer Manager.
2. Go to Paper Space.
3. Select the Viewports you wish to configure.
4. Apply the settings in the VP columns of the Layer Manager.

Note: Remember that settings which control object appearance via the Layer Manager (e.g. VP Color) only affect the properties objects which are set to By Layer.

Layer Manager Toolbar

Refresh: Refresh the Layer manager display.
New Layer Filter: Creates a new Layer filter. Assign a name to the filter then setup the filter in the Layer Filters dialog.
Edit Filter Parameters: Open the layer filter currently selected in the tree in the Layer Filters dialog.
Edit Layer Sets: Opens the Layer Set dialog to create and edit layer sets.
New Layer Template: Creates a new layer template from the currently selected layers.
New Layer: Creates a new layer. The default name will include a prefix by default, but the name can be changed.
Delete Layer: Deletes the layer.
Activate: Sets the currently selected layer (only one) as the active layer. This will effect any currently active drawing tool or currently selected object.
Select By: Selects all objects on the currently selected layers.
Edit Properties: Opens that layer page of the Drawing Options.
Visible/Invisible All: If any layer is invisible all layers are made visible. If all layers are visible they are all made invisible.
Invert Visibility: Turns all visible layers invisible, and all invisible layers visible.
Exclusive Visible: Makes only the currently selected layers visible, all other become visible.
Lock/Unlock All: If any layer is unlocked all layers are locked. If all layers are locked they are all unlocked.
Invert Lock: Exclusive Lock: Makes only the currently selected layers locked, all other become unlocked.
Layer Prefix: By default, the layers are named "Layer 1, Layer 2," etc. You can change or remove the prefix. The @ symbol is a placeholder for the automatic layer number. Note: Many of the functions available from the Layer toolbar are also available by right clicking and opening the local menu.

Creating a New Layer

1. Open the Layer manager by selecting Format / Layers, or by clicking the Layers icon on the toolbar. A dialog opens. In the dialog, right click on Layer and select new layer. Then assign a name for the layer in the Layer column (or accept the default name).
2. Adjust the various layer settings, such as color and line style.

Deleting a Layer

You may delete any layer except Layers 0. Layers can be deleted even if they contain objects. If the layer to be deleted is set as the default for a tool (in the General page of a tool's Properties window), you will receive a warning message before the layer is deleted.

1. Select Layers, and select the layer to be deleted.
2. Click Delete Layer. If the layer contains objects, the objects will be deleted. This action can be undone, in case you delete objects inadvertently.

In some cases, objects on deleted layers will be moved to Layer 0, rather than be deleted. If an object exists on Layer 1 in both Paper Space and Model Space, and Layer 1 is deleted from Model Space, in Paper Space the object will be moved to Layer 0. This is due to different Undo buffers for Model and Paper Spaces.

Construction objects are placed on layer "$CONSTRUCTION". You can change construction geometry color and line styles via the layer manager. You can now also delete $Construction layer and $Constraints layer by selecting them in the Layer palette (see Design Director-Layers).

Layer Templates

Layer templates allow you to create and save alternate configurations for layers. Layer templates store how layers are setup, but do not store layers thenselves. Layer templates are saved in a *.lrs file which can be stored anywher in you system directory.