Example of Layers and Subpictures

The user should be familiar with the possibilities this Drafting sub-system provides to create a structured drawing. Information can be grouped together either using

SUBPICTURES or LAYERS

Consider the following example: Suppose a map of the world is created in the system and that the user wants the possibility to change the colors of different parts of the world. The continents would be accessible groups. All countries would also be accessible groups, but belonging to a continent. The continent or a single country can then change color by a single command. Using subpictures, this is a simple task. The user that created this map also wants to have the same color on all English-spoken countries. This need can be supported by using layers. If all these countries are on the same layer, also this task is performed by a single command. Furthermore, layers can be given in levels (levels are explained below). This makes it possible to have for example, a country both on the English-spoken layer and on the NATO layer.