data converted into point features are stored in an INFO
DXF-IID item of all the attribute
table with the extension .XCODE.
entities associated with that IN-
When run through DXFARC, a coverage called
SERT.
CADDATA would produce an INFO table called
CADDATA.ACODE containing the following items:
ARC/INFO users can link attribute information from
the ATTRIB point features to the point features from
CADDATA-ID
ID of the coverage feature in its
the insert entities using the ARC/INFO RELATE com-
attribute table.
mand. See the ARC/INFO documentation for more
DXF-LAYER
Layer to which the entity belongs.
information.
DXF-COLOR
Color of the entity.
DXF-THICKNESS Thickness of the entity.
SUMMARY AND PROCESS STEP EXAMPLE
DXF-TYPE
Line type (continuous, dashed,
etc.) of the entity.
To summarize, Table 1 lists the AutoCAD data types
DXF-ELEVATION A single elevation value for the
to use in a drawing and the resulting data types after
entire entity: its Z coordinate.
conversion to an ARC/INFO coverage.
The following example is based on an AutoCAD
The CADDATA coverage could also produce an
drawing that contains information about the water dis-
INFO table called CADDATA.XCODE containing the
tribution system on a site (Figure 6). The water lines
following items for the points:
are stored on an AutoCAD layer called GIS_WATER.
The AutoCAD user digitizes these lines using the
DXF-LAYER
Same as for ACODE file.
AutoCAD POLYLINE command. The AutoCAD
DXF-COLOR
Same as for ACODE file.
DXFOUT command is used to create the WATER.DXF
DXF-ELEVATION
Same as for ACODE file.
file. Using DXFARC, the ARC/INFO user can now
DXF-ANGLE
Rotation angle in degrees.
extract the arc features and use BUILD. This creates
DXF-TYPE
Line type for the point feature.
the ARC/INFO arc and node features and their associ-
ated attribute tables. The water line information is stored
If a layer is converted by DXFARC with the
in an AutoCAD block, with three attribute tags to store
TEXTPOINT option, the XCODE file contains these
the pipe length, pipe identifier, and pipe type on an
additional items:
AutoCAD layer called GIS_WATER_DATA. The
AutoCAD user inserts these blocks using the AutoCAD
DXF-ANGLE
Angle of the text.
INSERT command and fills in the data fields when
DXF-SIZE
Size of the text.
prompted. The .DXF file is once again exported using
DXF-TEXT
Text value for the DXF-ATTRIB.
DXFOUT.
If the entity is a point, shape, or
Using DXFARC, the ARC/INFO user can now
insert, this field is blank.
extract the point features from the layer and BUILD
the point and annotation feature classes. Figure 7
If a layer is converted using the ATPOINT option,
details the command syntax used for the DXFARC com-
these additional items are added to the XCODE file:
mand. The .XCODE file contains the actual attribute
values for the points created in the DXFARC process.
DXF-ATTRIB
Holds the BLOCK name for IN-
This file can be joined back to the point attribute table
SERT points, the shape name for
(PAT) in ARC/INFO. Features with the same DXF-IID
SHAPE entities, and the tag or
field all belong to the same block insert.
item name for ATTRIB and
To find the nearest water line to the block insert point
ATTDEF entities.
features, use the ARC/INFO NEAR command. Figure
DXF-TEXT
Stores the item value for ATTRIB
8 details the command syntax used for the example.
and ATTDEF entities.
Note in the figure that no polygon features are actually
DXF-ATTRIB
Blank for text and point entities.
created at the time of conversion, rather, they are cre-
DXF-IID
Used to link attributes to the
ated by subsequent use of the ARC/INFO CLEAN com-
corresponding INSERT entity.
mand. As discussed above, as long as the geometry of
Each INSERT entity can have
the arcs is created correctly, correct polygon topology
multiple attribute entities. IN-
will follow.
SERT entities are converted to
Figure 9 shows the converted data, and Figure 10
point features with a unique user
summarizes the entire conversion process as a flow-
ID. This user ID is stored in a
chart.
10
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