A QGIS3 Script tool preparing data for custom orthographic projections.
The script have been developed based on an algorithm from Juernjakob Dugge (2016).
In QGIS, some features may not be drawn properly on orthographic projections. For example, the picture below shows some misrepresentation on the west of the globe.
The misrepresentation on orthographic projections might be fixed by two approaches: disabling the QGIS automatic simplification and clipping the layer to hemisphere, where the centre is at the origin of the orthographic projection. The following picture shows the layer clipped by the tool projected on an orthographic projection.
This script has been tested on QGIS 3.4 only, however; this would probably work with QGIS 3.X
At the processing toolbox panel, click on the Script button --> Add Script to Toolbox.... Then browse to the ClipToHemisphereAlgorithm.py and add the script.
- select your vector layer as your 'Input'.
- specify centre 'latitude and longitude of centre of your hemisphere' as your orthographic projection origin
- you may need to specify 'Number of segments for approximating the hemisphere. Higher number can get finer results but require longer processing time.
- select your output directory and click run
0.1 - first version