Feature Representation

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

GeoMedia features consist of geometric shapes which have their associated attributes as part of their definition. All GeoMedia features contain an fm0_type attribute, which identifies the geometric type. The feature contains additional attributes specific to its geometric type.

The common attributes of all GeoMedia features are shown in the following table. The table name is used as the feature type.

Attribute Name

Contents

fm0_type

The GeoMedia geometric type of this entity.

Range:

fm0_point

fm0_line

fm0_arc

fm0_area

fm0_text

fm0_collection

fm0_none

Default: No default

The blob breakdowns for the composite (aggregate), boundary (donut) and collection (aggregate) features are not mentioned below with the simple features, each of which has its corresponding attributes and blob data parsed.

Note: Geometries from FME do not map exactly to GeoMedia geometries. Usually, however, this is not an issue because although some of the internals of the geometries may be changed, their appearance in GeoMedia is still the same.

Additional attributes are described below.

Points

Closedfm0_type: fm0_point

GeoMedia point features specify a single set of coordinates, which is converted, and are devoid of any additional geometric attributes.

fm0_type: fm0_oriented_point

GeoMedia-oriented point features specify a single set of coordinates along with a rotation vector. This rotation attribute is stored as a rotation angle by the reader. Either a rotation angle or the individual components of a rotation vector may be passed to the writer.

Attribute Name

Contents

fm0_rotation

This attribute specifies an optional rotation for the shape where the clockwise direction is positive.

Range: -360 to 360 degrees

Default: 0

fm0_orientation_i

fm0_orientation_j

fm0_orientation_k

These attributes specify the components of the optional 3D rotation vector for a point. They may be used as a preferential alternative to the fm0_rotation attribute.

The vector components are written directly to GeoMedia and typically form a unit length vector.

Lines

Closedfm0_type:fm0_line

GeoMedia line features consist of a list of two or more points. No additional attributes are required to control GeoMedia lines.

Arcs

Closedfm0_type: fm0_arc

GeoMedia arcs consist of a start and end point as well as a normal vector and radius. From these points and their values, the center point of an arc, as well as the start and sweep angles, can be calculated and used to render the arc in FME format.

Note that the normal vector serves to identify an arc as being drawn either clockwise or counterclockwise. Similarly, a positive radius indicates an arc of greater than 180 degrees, while a negative radius indicates an arc of less than 180 degrees.

Areas

Closedfm0_type:fm0_area

GeoMedia area features specify various polygon features. An area is simply a closed line and can be an individual area, a donut, or an aggregate of areas. As with lines, there are no additional attributes for area features.

Text

Closedfm0_type: fm0_text

GeoMedia text is simple and straightforward, offering no font, color or style attributes. Text attributes include the string to be written, a rotation and a possible size.

Note: Although the reader attempts to provide a reasonable value for the text size, it may be necessary to adjust the text size during a Workbench or mapping file translation. Similarly, when writing, the result may have to be adjusted through the GeoMedia product for better results.

Attribute Name

Contents

fm0_justification

The alignment of the text around the origin

(not present in Reader)

Range: 0..2, 4..6, 8..10

0 centered vertically, centered horizontally

1 centered vertically, left of the origin

2 centered vertically, right of the origin

4 above the origin, centered horizontally

5 above the origin, left of the origin

6 above the origin, right of the origin

8 below the origin, centered horizontally

9 below the origin, left of the origin

10 below the origin, right of the origin

Default: 9

fm0_rtf_text_string

This attribute is used in both the reader and writer. If this attribute is set when reading, the original RTF text string from the source dataset will be included. If this attribute is set when writing, the RTF text string will be written. In this case, the keyword PLAIN_TEXT will be overridden by this attribute.

This option is provided for two main reasons:

  • When translating from GeoMedia to GeoMedia if the source dataset contains RTF text strings, then they will be translated without any loss of formatting information.
  • It gives the user the ability to supply custom formatted RTF text strings per feature, written out to the destination dataset.

Range: Any RTF character string. (No syntax verification done by the writer)

Default: None

None

Closedfm0_type:fm0_none

Features with no coordinates are tagged with this type when reading or writing to or from GeoMedia.

<ReaderKeyword>_DEF <tableName> \
[SQL_STATEMENT <sqlStatement>]	\
	FM0_GEOMETRY fm0_point|fm0_arc|fm0_line|fm0_area|	
	fm0_text|fm0_none	\
	[<attrName> <attrType>]+

Collections

Closedfm0_type: fm0_collection 

These are GeoMedia features that are heterogeneous aggregates of simple types.

For example, an aggregate of points, lines, and polygons can comprise a collection. There are no additional attributes required for collections.