ff_type: ff_polygon
FF polygon features represent closed area features and may be either 2D or 3D. The coordinate on the feature contains the location of the center. The IDs of the lines that make up the border of the polygon may be located in the appropriate attributes on these features.
Polygon features may have the following special attributes associated with them:
|
Attribute Name |
Description |
|---|---|
|
ff_up_cluster |
If this feature is linked to a cluster, this attribute will be present. Range: Yes |
|
ff_up_cluster_link |
If this feature is linked to a cluster, this attribute will contain the creation number of the parent cluster feature. Range: Integer |
|
ff_up_parent_link |
If this feature is an enclave—a hole with a centroid—within another polygon area, this attribute will be present. Also, if this feature is a member of a group, this attribute will be present. Range: Yes |
|
ff_up_parent |
If this feature is an enclave—a hole with a centroid—within another polygon area, this attribute will contain the creation number of the parent polygon feature. Otherwise, if this feature is a member of a group, this attribute will contain the creation number of the parent group feature. Range: Integer |
|
ff_down_point_link |
If this feature is linked to a centroid point, this attribute will be present. Range: Yes |
|
ff_down_point |
If this feature is linked to a centroid point, this attribute will contain the creation number of the centroid point. Range: Integer |
|
ff_down_poly_link |
If this feature is linked to edges of the polygon, this attribute will be present. Range: Yes |
|
ff_down_edge_ptr{} |
If this feature is linked to edges of the polygon, this list attribute will contain the creation numbers of the outer edges of the polygon. Range: Integer |
|
ff_down_hole_start_ |
If this feature is linked to edges of the polygon, this list of list attributes will contain the creation numbers of the edges of all the holes in the polygon. For example, the creation number for the third edge of the second hole would be found in the attribute ff_down_hole_start_ptr{1}.{2}. Range: Integer |
|
ff_down_enclave_link |
If this feature is linked to enclaves—polygons with centroids—within the polygon, this attribute will be present. Range: Yes |
|
ff_down_enclave_ptr{} |
If this feature is linked to enclaves—polygons with centroids—within the polygon, this list attribute will contain the creation numbers of the enclaves it contains. Range: Any real number |
|
ff_area_point_x ff_area_point_y ff_area_point_z |
These attributes do not appear on features read from FF files. If these attributes are on a feature when written to FF, they specify the location to use as the centroid of the polygon instead of automatically generating one. Range: Any real number |