Feature Representation

In addition to the generic FME feature attributes that FME Workbench adds to all features (see About Feature Attributes), this format adds the format-specific attributes described in this section.

The AutoCAD Map 3D Object Data Reader and Writer support all of the same features supported by the AutoCAD RealDWG Reader and Writer and additionally uses the exact same attributes (i.e., all the format-specific attributes are prefixed by autocad, not by autocad_od). Unlike the AutoCAD RealDWG format, the feature representation used by the AutoCAD Map 3D Object Data format is based on the setting of the OD_READING_MODE. See the Workbench Reader Parameters for details.

The AutoCAD Map 3D Object Data Reader and Writer support encoded character strings specifically in FME feature attributes that represent object data field values.

Object data fields whose type is Point will be converted by the Autodesk Map 3D Object Data reader into three attributes: one for each of the x,y,z coordinates. For example, if the name of a Point field is LOCATION, the AutoCAD Map 3D Object Data reader will split the field into the following attributes: LOCATION.x, LOCATION.y, and LOCATION.z. The x, y, or z characters, which specify the dimension of each point attribute, must be lowercase.

All AutoCAD Map 3D Object Data features that have some object data associated with them will have the attributes described in the table below.

Attribute Name	Contents
autocad_layer	The name of the feature’s layer. This is stored when reading for reasons of convenience. This value is ignored when entities are being written to a DEF line which defines a layer. However, if a feature is being written to a DEF line that defines an object data table, this attribute specifies the name of the layer to which entity information will be written, and will take precedence over layer naming by feature type fanout. In the absence of this attribute, the DEF line name will be used for the layer name. For the AutoCAD Map 3D Object Data Writer, the length of the feature type name is limited, similarly to the value of the autocad_map_odtable attribute. This will also limit the name of the layer created, unless this attribute is explicitly set, to set a different layer name. Value: char(50) Default: No default
autocad_entity	The FME name for the type of entity this feature represents. The AutoCAD Map 3D Object Data Reader and Writer make use of an additional value autocad_od_table to represent FME features that do not have entity information but which store object data information on their attributes. Range: See the table AutoCAD Entity Types and Descriptions Default: No default
autocad_map_odtable	The name of the object data table from which the object data, stored on the feature as attributes, was retrieved. The AutoCAD Map 3D Object Data Reader will create all FME features with this value in all settings of OD_READING_MODE. If a feature is being written to a DEF line that defines an object data table, this attribute specifies the name of the object data table to which attribute information will be written, and will take precedence over object data table naming by feature type fanout. In the absence of this attribute, the DEF line name will be used for the object data table name. Value: char(30)
autocad_od_entity_key	A unique value per entity that is used to associate object data features with duplicate entity information or associated object data information. The AutoCAD Map 3D Object Data reader will create all FME features that have object data with this value when the OD_READING_MODE is set to od_mode_raw or od_mode_classic. The AutoCAD Map 3D Object Data writer will only write entity information once for each unique value of the attribute. Value: char(30)

Note: If block references have associated object data it will be attached to the insert point for the block. If block references have parts that have associated object data, and blocks are exploded, the object data associated with the block parts will be attached to the features created for the block parts. However, if attribute entities or insert attribute entities are expanded into text entities when reading, the object data will not be read. The object data on insert attribute entities can be found on the non-geometric attribute definition features that result from exploding a block that contains insert attributes.