AutoCAD® 2002 - Autodesk

OBJECT Section Group Codes
Objects are similar to entities, except that they have no graphical or geometric
meaning. All objects that are not entities or symbol table records or symbol
tables are stored in this section. This section represents a homogeneous
heap of objects with topological ordering of objects by ownership, such that
the owners always appear before the objects they own.
Object Ownership
The root owner of most objects appearing in the OBJECTS section is the
named object dictionary, which is, therefore, always the first object that
appears in this section. Objects that are not owned by the named object dictionary
are owned by other entities, objects, or symbol table entries. Objects
in this section may be defined by AutoCAD ® or by applications with access
to ObjectARX API. The DXF names of application-defined object types
should always be associated with a class name in the CLASS section of the
DXF file, or else the object record cannot be bound to the application that
will interpret it.
As with other dictionaries, the named-object dictionary record consists solely
of associated pairs of entry names and hard ownership pointer references to
the associated object.
To avoid name collision between objects, developers should always use their
registered developer prefix for their entries.
Common Group Codes for Objects
The following table shows group codes that apply to virtually all nongraphical
objects. When you refer to a table of group codes by object type, a list of
codes associated a specific object, keep in mind that the codes shown here can
also be present. Some of the group codes are included with an object only if
the object has nondefault values for those group code properties. For information
about abbreviations and formatting used in this table, see “Formatting
Conventions in This Reference” on page 6.
116 | Chapter 7 OBJECTS Section