Visualising Rally Route Stages (with help from rayshader and some ecologists…)

Inspired by some 3D map views generated using the rayshader and rgl R packages, I wondered how easy it would be to render some 3D maps of rally stages.

It didn’t take too long to get a quick example up and running but then I started wondering what else I could do with route and elevation data. And it turns out, quite a lot.

The result of my tinkerings to date is at rallydatajunkie.com/visualising-rally-stages. It concentrates soley on a "static analysis" of rally routes: no results, no telemetry, just the route.

Along the way, it covers the following topics:

• using R spatial (sp) and simple features (sf) packages to represent routes;
• using the leaflet, mapview and ggplot2 packages to render routes;
• annotating and splitting routes / linestrings;
• downloading elevation rasters using elevatr;
• using the raster package to work with elevation rasters;
• a review of map projections;
• exploring various ways of rendering rasters and annotating them with derived terrain features;
• rendering elevation rasters in 2D using rayshader;
• an aside on converting images to elevation rasters;
• rendering and cropping elevation rasters in 3D using rayshader;
• rendering shadows for particular datetimes at specific locations (suncalc);
• stage route analysis: using animal movement trajectory analysis tools (trajr, amt, rLFT) to characterise stage routes;
• stage elevation visualisation and analysis (including elevation analysis using slopes);
• adding OpenStreetMap data inclduing highways and buildings to maps (osmdata);
• steps towards creating a road book / tulip map using by mapping stage routes onto OSM road networks (sfnetworks, dodgr).

Along the way, I had to learn various knitr tricks, eg for rendering images, HTML and movies in the output document.

The book itself was written uisng Rmd and then published via bookdown and Github Pages. The source repo is on Github at RallyDataJunkie/visualising-rally-stages.