We live in a three-dimensional world. To design objects for everyday living, users must learn how to create in three dimensions. For precise modern designs that must conform to certain specifications and tolerances, we use computers to create a digital model first, and then pass that model on to a machine, such as a CNC router or 3D printer for fabrication. There are many software packages that are used to create digital models. One such package that is growing in popularity among designers, machinists, and architects is Rhinoceros 3D, or Rhino. Grasshopper is a visual scripting platform. It allows the user to write computer programs to build Rhino objects by simply dragging boxes around the screen and connecting them with wires. And the beauty is that no knowledge of programming is necessary! Modeling with Grasshopper adds the potential for infinite customization to the design process. This work provides an introduction to modeling objects with Grasshopper, and helps to teach readers how to organize their data, including geometric objects, modeling operations, and numerical data into lists and data trees.Emphasis is put on the way the Rhino components can be put together in Grasshopper script to create the readers' desired object(s).In Part I, Bachman offers a brief overview of scripting with Grasshopper, detailing specific components. In Part II, more complicated Grasshopper scripts are presented, showcasing the variety of objects readers can create and have at their disposal. All examples were carefully chosen to point back to Part I, so that readers can see how the concepts can be put together to create increasingly complex designs. Finally, Part III features a reference guide from Grasshopper's own help files containing descriptions of some of the most common Grasshopper components.