Graphical Representation

Representation Rules control how Design elements are drawn. Each Rule can specify a given type or types of element, or named elements. Representation Rules refer to Styles. The attributes of a Style define a series of drawing styles and colours, for example, for frontface, backface and centreline, and whether items such as p-lines and obstruction volumes are shown. for further information about styles and colours see Colors and Styles.

Representation Rules also control which design elements are to be replaced by symbols when a 2D View is created. For a description of 2D symbology, refer to 2D Symbolic Representation.

Representation Rules can be created in a Library and be referred to from a VIEW, or they can be owned directly by a VIEW, in which case they are known as local rules. Local Rules override Library Rules. See Local Rules for further information about the order in which Rules are applied.

Representation Rules (RRUL) are stored in Representation Rulesets (RRST), which in turn are owned by Representation Libraries (RPLB).

RPLBs are also used to store STYLs. The reference from an RRUL to a STYL is made by setting the STYF attribute of the RRUL. When a View references a RRST, the reference is made by setting the RRSF attribute of the View.

Figure 4:1. Representation Rules Database Hierarchy

This Section also describes Hatching Rules, which are used for automatic hatching of faces of Design elements. See Automatic Hatching.

For further information on how changes to design elements can be shown, see Change Highlighting.