Observations with spacecraft-mounted instruments are usually limited by their field-of-view and are often affected by the spacecraft's shadow or wake. Their extent though can be derived from the spacecraft's geometry. In this work we present a robust method for calculating the field-of-view as well as the extent of a spacecraft shadow and wake from readily available spacecraft CAD models. We demonstrate these principles on Cassini, where we give examples of vector-spacecraft intersection for the Cassini Langmuir Probe, as well the field-of-view of the Langmuir Probe and the Cassini Plasma Spectrometer.