Feature Representation (VPF Reader)

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 VPF reader produces FME features for VPF feature class features as well as VPF metadata table entries when a reader is invoked in database mode (VPF_DB).

There are many types of FME features produced for metadata at every level of a VPF database.

At the root level of the database, FME features are produced for:

  • Database Header Table (DHT)
  • Library Attribute Table (LAT)
  • Data Quality Table (DQT) (if it exists)

At the library level of the database, FME features are produced for:

  • Coverage Attribute Table (CAT)
  • Library Header Table (LHT)
  • Geographic Reference Table (GRT)
  • Data Quality(DQT) and Lineage Document (LINEAGE.DOC) Tables (if they exist)

At the coverage level of the database, FME features are produced for:

  • Character and Integer Value Description Tables (CHAR.VDT, INT.VDT)
  • Symbol and Notes Related Attribute Tables (SYMBOL.RAT, NOTES.RAT)
  • Feature Class Attribute and Schema Tables (FCA) and (FCS)
  • Data Quality Table (DQT)
  • coverage document table (<coverage name>.DOC)
  • feature class document tables (<feature class name>.DOC)

With the exception of the feature class schema table (FCS), all coverage metadata tables are optional and FME features are only produced for metatables that exist.

An FME feature is produced for each row in each metadata table that is processed. For each column in a metadata table, there is one attribute in an FME feature with the same name and type as the column. The value of each attribute will be the same as the row from which the feature was produced. No geometric information is attached to features that are produced from metadata tables.

The other type of FME features that this reader produces result from VPF feature class features. This type of feature can have zero or more geometries attached to it. For this reason, all of the FME features produced for these VPF features contain an aggregate of geometries. For most feature class geometry types, all geometries in the resulting features are the same type—the type of the table. For complex feature classes, a single feature can contain any mixture of text, point, line, and area features.

The attributes for each geometry are given by the attribute component{<n>}.<attrName>, where n is the position of the geometry in question with the first one being at position 0, and <attrName> is the geometry-specific attribute in question.

The attributes defined for each geometry are totaled in the following table.

Name

Description

Defined On

vpf_type

The type of this specific geometry. This has one of the following values:

vpf_area

vpf_line

vpf_point

vpf_text

All geometries

vpf_database_name

The name of the database to which the feature belongs.

 

vpf_library_name

The name of the library to which the feature belongs.

 

vpf_coverage_name

The name of the coverage to which the feature belongs.

 

vpf_feature_class

The name of the feature class to which the feature belongs.

 

vpf_tile_name

The name of the tile in which the feature lies.

The tile_name also depicts relative tile path.

 

vpf_containing_face

This attribute is present for entity nodes for level 3 topology.

It contains the face_id of the area containing the node.

 

vpf_first_edge

This attribute contains the edge_id of the first_edge of a connected node.

This attribute will be present for level 1 and higher topology.

 

component{#}.attributeName

 

e.g.,

component{#}.vpf_type

List attributes of the parts of the geometry and defines the geometry-specific attributes on the feature. For example,

component{0}.vpf_typemeans the vpf_type of the first component of the feature.

 

vpf_text_string

The string to be displayed for a vpf_text geometry.

vpf_text

vpf_text_height

The height of a vpf_text geometry.

This is automatically extracted from the SYMBOL_RAT{0}.SIZE attribute. Although the VPF standard does nto explicitly specify this attribute it is used to preserve the point size of the text feature when specified. It s used in combination with vpf_text_scale to calculate the text height in ground units stored in fme_text_size attribute will be automatically deleted in case the fme_text_sizeis modified. (See the information under the heading Special Attribute Handling.)

vpf_text

vpf_text_font

The font used to display vpf_text geometry.

This is automatically extracted from the SYMBOL_RAT{0}.FONT or SYMBOL_RAT{0}.FON attribute.

See Special Attribute Handling.

vpf_text

vpf_text_color

The color used to display vpf_text geometry.

This is automatically extracted from the SYMBOL_RAT{0}.COLOR or SYMBOL_RAT{0}.COL attribute.

See Special Attribute Handling.

vpf_text

vpf_text_style

The style used to display vpf_text geometry. This is automatically extracted from the SYMBOL_RAT{0}.STYLE or SYMBOL_RAT{0}.STY attribute.

See Special Attribute Handling.

vpf_text

vpf_rotation

The rotation at which the text is to be displayed.

This is calculated from the lower left and lower right coordinates of the text line, and is expressed in degrees counterclockwise from due east. It defaults to 0.0 if the text geometry has only one coordinate in the VPF data.

vpf_text

vpf_text_scale

The scale read from the Library Header Table (LHT) in the library containing the feature.

A default scale of 0, 1000000 will be used if no scale is specified. Scale is used in combination with vpf_text_height to calculate the fme_text_size.

vpf_text

vpf_original_geometry

Optional

The original geometry as read by the VPF Reader in the Well Known Text (WKT) format for when text geometries are not a simple single point. Used to preserve the original text geometry. This attribute will be deleted if fme_rotation is modified.

This attribute is only present if the shape line contains more than one coordinate pair.

The order of coordinate pairs follows the specs found in VPF: the first coordinate pair represents the lower left coordinate, and the second coordinate pair defines the lower right of the string. Third and subsequent coordinate pairs define control points in a shape line, i.e the points in between the first and second pairs.

vpf_text

vpf_sequenced_geometry

Optional

It is similar to vpf_original_geometry except for the order of the coordinate pairs. The list of coordinate pairs in this attribute is sequenced, i.e., the second coordinate pair in vpf_original_geometry is moved to the end of the list in vpf_sequenced_geometry.

This attribute is only present if the shape line contains more than one coordinate pair.

vpf_text