In sketching, what is the function of a hidden line?

In sketching, a hidden line serves the crucial function of depicting edges that are not visible from the current viewpoint. These lines are represented as dashed or dotted lines, which enable the viewer to understand the shape and complexity of an object by conveying information about features that are behind or inside the visible surfaces. This visual addition helps in providing a more comprehensive understanding of the three-dimensional form of the object, allowing for better interpretation during design discussions or evaluations.

By employing hidden lines, designers can communicate important details without obscuring the overall representation of the object, ensuring clarity and completeness in the drawing. This is essential in engineering design, where visual accuracy is key to effective communication of ideas and specifications.