The impact of normal mapping on the appearance of geometrically simplified archaeological 3D models

A great challenge in 3D digitization and modelling lies in striking a balance between surface detail and model size, while accommodating the geometric information representation requirements of diverse archaeological practices. 3D meshes that contain a high polygon count severely impact storage requirements, data transmission, and 3D rendering. It is therefore typical for high-resolution digitized objects and modelled assets alike to be sub-sampled and simplified into levels of detail (LODs) to match the requirements of the intended applications. By doing so, however, geometric detail is lost, negatively affecting the model’s visual fidelity during 3D visualization. Normal mapping offers a reliable and practical solution to this challenge by transferring surface orientation data from the original, detailed models into simplified versions. This approach preserves the key visual characteristics present on the surface of a high-detail model, without reintroducing geometric complexity into the simplified structure. In archaeological contexts, where both accuracy and accessibility are important, normal mapping enables lightweight models to maintain the perceptual qualities of high-resolution originals, while supporting diverse visualization applications, from analytical inspection to public dissemination. In this paper, our proposed methodology explores the robustness of detail transfer through normal mapping on simplified archaeological models, highlighting its effectiveness as a tool for efficient cultural heritage visualization and immersive applications. The study claims that normal-mapped models can effectively stand in for the original high-detail scans in a variety of scenarios, thus offering a viable and efficient alternative to the demanding storage and transmission of high-fidelity 3D models.