  The contact goniometer is a commonly used tool in lithic and
zooarchaeological analysis, despite suffering from a number of shortcomings due
to the physical interaction between the measuring implement, the object being
measured, and the individual taking the measurements. However, lacking a simple
and efficient alternative, researchers in a variety of fields continue to use
the contact goniometer to this day. In this paper, we present a new goniometric
method that we call the virtual goniometer, which takes angle measurements
virtually on a 3D model of an object. The virtual goniometer allows for rapid
data collection, and for the measurement of many angles that cannot be
physically accessed by a manual goniometer. We compare the intra-observer
variability of the manual and virtual goniometers, and find that the virtual
goniometer is far more consistent and reliable. Furthermore, the virtual
goniometer allows for precise replication of angle measurements, even among
multiple users, which is important for reproducibility of goniometric-based
research. The virtual goniometer is available as a plug-in in the open source
mesh processing packages Meshlab and Blender, making it easily accessible to
researchers exploring the potential for goniometry to improve archaeological
methods and address anthropological questions.
