The Virtual Goniometer: A new method for measuring angles on 3D models of fragmentary bone and lithics

TL;DR

The paper introduces a virtual goniometer tool for measuring angles on 3D models, offering increased speed, consistency, and access to otherwise unreachable angles compared to traditional contact goniometers.

Contribution

It presents a novel virtual goniometer method integrated into open source 3D mesh software, improving measurement reliability and accessibility in archaeological and anthropological research.

Findings

Virtual goniometer is more consistent than manual methods.

It enables rapid and precise angle measurements.

Accessible as a plugin in Meshlab and Blender.

Abstract

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.