The scatter3D function draws the scatterplot, and we have an interesting set of options for it. We can turn the color key on/off using the colkey parameter. phi and theta control the angles that will be used to show the plot. The color key is quite useful as it helps to highlight the observations that have higher Z values. This is useful because in 3-D plots it is sometimes difficult to understand a single image without rotating it. We are also using the text3D function to print the values for Z for each point. This step could certainly be omitted, but it is generally useful for isolating individual observations.