Automatic Overview Layer Generation

When creating a map that uses a large amount of data it is necessary to insert a set of additional detail layers using less detailed data into the map in order to control the amount of memory required to view large areas of the map. If no suitable data is available for use in creating manual overview layers then MapLink Pro Studio can generate suitable layers during map creation using the other detail layers in the map.

When enabled MapLink Pro Studio will determine the necessary number of additional detail layers that need to be created based on the contents of the current project and create them automatically when the map is generated. These additional layers are rasterised versions of the least detailed layer of the map. MapLink Pro Studio will determine an appropriate raster format by examining therequested raster format for the data files in the least detailed map layer. If this layer does not contain any rasters, then the default raster format will be used.

While the default settings for layer generation should be reasonable for most situations, there are several additional options to allow for finer control over the generation process. These are:

• The Overview layer base name. This controls the name of the additional detail layers that will be inserted into the generated map. A number is appended to this name for each overview layer inserted.
• The layer resolution percentage. This value defines the size of each overview layer generated as a percentage of the layer it was generated from. For example, a value of 25% means that the initial overview layer will be 25% of the resolution of the least detailed detail layer in the project file. The next overview layer will be 25% of the resolution of the initial overview layer, and so on.
• The initial layer fixed resolution. This value allows the resolution of the initial overview layer to be set independently of any detail layers in the project. This can be useful when creating overview layers for purely vector maps if MapLink Pro Studio does not insert the initial overview layer at the desired resolution automatically.

To enable overview layer generation

• From the Map menu, select Properties.
• Select the 'Raster Overview' tab.
  
• Tick the 'Enable automatic raster overview generation' checkbox.
• Press OK.