Attribute Behavior

In this context, attributes are defined as data associated directly with a particular geometry entity. In Trelis' implementation of attributes, these data can occupy one of three "states" at any given time: they can be stored in data fields on Trelis' geometry entities; they can be stored in an intermediate representation, using Trelis' attribute objects; or they can exist only on the ACIS objects. When they are stored on ACIS objects, those attributes are written to and read from disk files with the geometry. This mechanism allows Trelis-specific information to be stored and retrieved with the geometry data. By default, attribute data is not stored with geometry. To enable the use of attributes, use the commands described in the following sections.