The track seen with Polycam”: a comparative study of SfM-based 3D documentation applied to architectural structures and decorative motifs at the Holy Sepulchre (Jerusalem)

This paper presents a comparative analysis of two Structure from Motion (SfM) photogrammetry tools — Agisoft Metashape (desktop) and Polycam (mobile) — applied to the 3D documentation of architectural features and decorative elements at the Church of the Holy Sepulchre in Jerusalem. Conducted within an ongoing archaeological investigation by Sapienza University of Rome, this study evaluates the effectiveness, accuracy, and workflow adaptability of both platforms in field conditions. Two wall sections (LW J32 and LW J76) and a decorated marble base (G72) were selected for detailed modeling using both tools. Results show that Metashape delivers high-resolution meshes suitable for advanced archaeological analysis, particularly under controlled lighting and with DSLR image sets. In contrast, Polycam enables rapid, on-site documentation in spatially constrained areas, producing geometrically accurate models with acceptable visual quality. The integration of Polycam and Metashape workflows also demonstrated potential for hybrid strategies, where mobile scanning complements high-end processing. This approach proved especially effective in documenting partially obstructed or hard-to-access features. The study confirms the value of using both tools in a complementary manner to enhance archaeological recording, visualization, and interpretation workflows in complex excavation settings.