How to route through one or multiple buildings or floors is what this recipe is all about. This is, of course, the most complex situation involving complex data collection, preparation, and implementation processes. We cannot go into all the complex data details of collection and transformation from ACAD to PostGIS, for example; instead, the finished data is provided.

To create an indoor routing application, you need an already digitized routing network set of lines representing the areas where people can walk. Our data represents the first and second floor of a university building. The resulting indoor route, shown in the following screenshot, starts from the second floor and travels down the stairs to the first floor, all the way through the building, heading up the stairs again to the second floor, and finally reaching our destination.