Introduction

The VPF filter that was provided with MapLink Pro 3 has been superseded by a new filter that provides a higher level of flexibility and configurability when processing VPF data, as well as support for VPF datasets that were not handled within MapLink Pro 3. For users familiar with the MapLink Pro 3 VPF filter, the following points should be noted:

• The two-stage process involving the user of the VPF Query Tool to generate a set of intermediate .VPF files has been replaced with a single stage process. As a result, the VPF Query Tool is no longer used.
• The feature configuration is now fully definable by the user, instead of being controlled by the contents of a separate configuration file. As a result, the VPFFIELD.INI configuration file is no longer used.
• Text generated from feature attribute information is no longer created with separate feature codes, but with the same feature code as the corresponding geometric primitive. This approach is in line with the behaviour of the other MapLink filters.
• In MapLink 3 the FACC field was used as the basis for each separate feature code. In MapLink 4 a more generic approach, which is better suited to use in other VPF datasets, is used. As a result, the basis of each feature code is the Feature Class. Equivalents to the MapLink 3 feature codes for VMAP0 data can be created by using the FACC as the attribute for the first level of feature subclassing.

Existing MapLink projects that have been created using MapLink 3 will still use the MapLink 3 version of the VPF filter for existing VPF datasets when they are opened using MapLink 4. However, any new VPF datasets that are added will use the new VPF filter.

If necessary, you can still add MapLink 3 VPF datasets to a MapLink 4 project, by following the procedure defined below.

To add a MapLink 3 VPF dataset to a MapLink 4 project

• Close MapLink Pro Studio.
• Open the file mapl.ini (which is to be found in the MapLink \config directory) using any text editor.
• Search for the [VPF-MAPLINK3] section of the INI file.
• Within this section, change the line "FILTERDEF=0" to "FILTERDEF=1".
• Save the INI file.
• Run MapLink Pro Studio and either open an existing project or create a new project.
• Select Layer | Add Dataset The Dataset Type list will now include an entry for [VPF-MAPLINK3].
• Select this entry, together with an appropriate Feature Book section, and press OK. The MapLink 3 VPF dataset will be added to the project.

Note that the VPF Query Tool that was supplied with MapLink 3 is no longer accessible from the main menu of MapLink Pro Studio, because it is not used in the MapLink 4 VPF filter. However the tool is still shipped, and can be found in the MapLink \bin directory.