Book Image

QGIS Python Programming Cookbook, Second Edition - Second Edition

By : Joel Lawhead
Book Image

QGIS Python Programming Cookbook, Second Edition - Second Edition

By: Joel Lawhead

Overview of this book

QGIS is a desktop geographic information system that facilitates data viewing, editing, and analysis. Paired with the most efficient scripting language—Python, we can write effective scripts that extend the core functionality of QGIS. Based on version QGIS 2.18, this book will teach you how to write Python code that works with spatial data to automate geoprocessing tasks in QGIS. It will cover topics such as querying and editing vector data and using raster data. You will also learn to create, edit, and optimize a vector layer for faster queries, reproject a vector layer, reduce the number of vertices in a vector layer without losing critical data, and convert a raster to a vector. Following this, you will work through recipes that will help you compose static maps, create heavily customized maps, and add specialized labels and annotations. As well as this, we’ll also share a few tips and tricks based on different aspects of QGIS.
Table of Contents (16 chapters)
QGIS Python Programming Cookbook - Second Edition
About the Author
About the Reviewer
Customer Feedback

Visualizing data in 3D with WebGL

QGIS displays data in a two dimensions even if the data is three dimensional. However, most modern browsers can display 3D data using the WebGL standard. In this recipe, we'll use the Qgis2threejs plugin to display QGIS data in 3D in a browser.

Getting ready

You will need to download some raster elevation data in the following zipped directory and place it in your qgis_data directory:

You will also need to install the Qgis2threejs plugin using the QGIS plugin manager.

How to do it...

We will set up a color ramp for a DEM draped over a hillshade image and use the plugin to create a WebGL page to display the data:

  1. First, we will need to import the relevant libraries and the plugin:

            from PyQt4.QtCore import QSize 
            from qgis.core import QgsCoordinateReferenceSystem,
                                  QgsCoordinateTransform, QgsPoint 
            from Qgis2threejs.api import Exporter...