a new record of pre-columbian engravings in urubici (sc), brazil using polynomial texture mapping

In this article we evaluate the application of Polynomial Texture Mapping (PTM), a technique within Reflectance Transformation Imaging (RTI), to a group of pre-Columbian rock art panels in southern Brazil. Our case study, the Avencal 1 rock art site (Urubici, Santa Catarina state), is one of the largest and most recognised sites in the southern Brazilian highlands. This study is the first detailed analysis of the site since it was recorded five decades ago. The record produced with PTM is more complete when compared with preceding sketches. Furthermore, its utility as a prospection tool is underscored by revealing for the first time the existence of multiple eroded motifs. Interpreting the PTM data, we recognise several new aspects of the panels that have gone unnoticed. Discrepancies between the published plans and the panels are illustrated, as are hypothesised sequences of production for specific panels and multiple techniques of engraving used at Avencal 1. Following our study, it is clear that PTM has applications for both analysis and conservation of pre-Columbian rock art and beyond. This article is accompanied by the dataset produced from our project in Urubici, which is referred to extensively. The data files are hosted by the Archaeology Data Service.