As mentioned above, a configuration file, called S57Styles.txt, is available to indicate the style to represent each map feature, based on its S57 code. For example:

Each line of this file describes how to represent a particular S57 feature according to its coding attribute. Each line contains comma-separated fields, and has the following structure:

Where the possible stroke styles are:

You can modify this file (S57Styles.txt) which is located in <$ILVHOME>/data/maps/s57. You can also create your own version of S57Styles.txt in another directory specified by the environment variable ILVMAPSS57STYLES. However if you use this last method, the new directory must contain all necessary bitmaps which are defined in the S57Styles.txt. For the syntax, see the original file or above.

As you can see, this configuration file allows you to easily customize global rendering settings with a simple and flexible syntax. Advanced configuration is also possible by defining your own rendering strategy. In this case, you need to create your own Renderer, that can be derived from the standard S57 Renderer ( IlvS57Renderer class), and implement your own logic for turning S57 information into appropriate graphics. For example you could decide to group some S57 features together on particular map layers, or you could implement advanced rendering based on other visual standards.