surface_plot: Make an interactive plotly plot of a function of two variables
Description
An interactive plot lets you interrogate the plot to get
numerical values at each point. When type = "surface", the
plot can be rotated to see the "shape" of the function from
various perspectives. Using the interactive controls, you
can save the plot as a PNG file. But it's not possible to overlay
plots the way you can with contourPlot().