Practical GIS

Styling vector data

Unlike raster data, which can be styled by their individual raster values, vector data can be styled statically, or by their attributes. Basic styling includes a simple style for a layer. For polygons, it is a simple fill with an outline, a simple line for lines, while for points, it is a scale independent circle with an outline. If we open the Properties window of a vector layer, and navigate to the Style tab, we can see the Single symbol method applied to the layer.

These are cascading styles, starting in a parent class, which is predefined for the geometry type and is unchangeable. These styles are truly cascading, therefore, if we change a global attribute, like the color on any member, the whole structure conforms. ...