In this chapter, we examined several techniques of creating complex shapes using D3.js path data generators. We started with examples of common generators, including line, area, circles, donuts, arcs, and diagonals. These are extremely powerful tools and enhance your ability to create complex visualizations easily.

We finished the chapter with an examination of line interpolators, a means of informing the line path generator of how to fit lines between data points. These interpolations, including the default linear interpolation, are for the basis of efficiently creating complex line graphs and curved shapes that fit data.

In the next chapter on layouts, we will move a little higher up the visual stack of D3.js to examine layouts, which are essentially generators for complex data visualizations.