QuadGrid: fast spatial data generalization for the best LoD

There’s a bunch of different ways to generate contour lines [1] from scatter data, each of them based on different interpolation algorithms. Like KNN [2], IDW [3] or kriging-flavoured methods [4]. (image from Wikipedia)

0. What’s this and what’s not

First of all, what is an isovist? It’s simply the same as a viewshed… and what the heck is a viewshed? Let’s go to the Wikipedia:

To write te article Spies in the sky, the authors needed a multi-step analysis, explained here

If you want to work with official buildings data in Spain, you can go to Sede Electrónica del Catastro and download the public available vector there. Within the data package, you’ll find a CONSTRU dataset with building information.