chRistmas tRees

Year over year, in the last classes before Christmas I ask my students to create a Christmas tree in R.
Classes are about Techniques of data visualisation and usually, at this point, we are discussing interactive graphics and tools like rbokeh, ggiraph, vegalite, googleVis, D3, rCharts or plotly. I like this exercise because with most tools it is easy to create a barchart, but how good must be the tool and the craftsman to handle a christmas tree?

Here is what they did this year (having around 1 hour to finish the task). Knitr scripts.

Update: I am still getting new submissions, feel free to submit yours as well.