Reference:
https://stackoverflow.com/questions/35087728/plot-3d-graphs-in-r-studio/35088125
https://www.r-bloggers.com/3d-plots-in-r/
http://www.sthda.com/english/wiki/impressive-package-for-3d-and-4d-graph-r-software-and-data-visualization
https://www.dummies.com/programming/r/how-to-install-load-and-unload-packages-in-r/
https://stackoverflow.com/questions/36125313/3d-plot-of-normal-distribution-in-r-around-a-x-y-point