A drawing can consist of a number of drawing layers, each being similar to a transparency on a traditional drawing board. You can create as many layers as you wish and give them meaningful names. Every entity you draw must be drawn into one of the drawing's layers.
Whenever a new drawing is created, it is automatically given at least one layer (the number of layers and their names depend upon which template you chose when creating the drawing). Every drawing layer must be given a unique name when it is created.
Use File - New - Drawing Layer to add a new layer to your current drawing, or Edit - Delete Current Layer to delete the current layer. Use Options - Project to manage the layers via the Design Options form.
You can copy or move selected entities into another layer of the same drawing using Edit - Copy To Other Layer.
You can copy an entire layer from any open drawing into the current drawing using Block - Copy Layers.
Layers can also behave like blocks, with one layer inserted into another (for example a one-up layer inserted multiple times into a multi-up layout). Use Block - Insert Drawing Layers to create such insertions. Once created, you can move into these layer insertions much as you would with blocks.
The layer and block structure of all open drawings is shown on the Drawings Hierarchy page of the Impact Explorer. Click a layer name to change your current layer, or right-click to display a context menu which is described in detail in the Drawings Hierarchy description.
Your system could be configured to include the current layer name on the Design Bar. This will be in the form of a pulldown list containing all the drawing layers, with the current layer at the top of the list. You can change the current layer by selecting another name from the list. See also the section below on Special Key-presses.
Individual layers can be locked, via the Project Browser. It is also possible for different users to be working on different layers of the same project at the same time - see Projects.
Layer Tabs
These are located at the bottom of the drawing area. A description of their use can be found here.
Layer Types
Every layer is of a particular type. There are three pre-defined types:
- one-up (database table: ONE_UP)
- multi-up (database table: MULTI_UP)
- 3D (database table: THREE_D)
The layer type defines how the layer may be used (for example the layout tools expect your designs to be in one-up layers and your layout to be in a multi-up layer; similarly the 3D tools create layers of type 3D).
The type of layer defines what database information is stored; this may be viewed/modified for the current layer using Database - Layer.
You can create your own custom layer types by creating new layer database tables using Database - Administration.
Special Key-presses When Changing Layers
Normally when changing your current layer via the Layer list on the Impact Explorer Drawings Hierarchy page or using the Layer Tabs at the bottom of the drawing area, the following actions occur:
- the new current drawing layer is made visible, all other drawing layers are made invisible
- a View - Extents operation is performed, so that all visible entities fit on the screen
You can override these actions by holding down the Shift and/or Control keys when clicking on the drawing layer name in the list (or on the Layer Tab):
- holding the Shift key when changing layers suppresses the View - Extents
- holding the Control key when changing layers suppresses the making invisible of other drawing layers; that is all the layers that are currently visible plus the layer changed into will be visible
You can hold down both keys to achieve a combined effect.