Abstract3D reconstruction methods can be used to obtain digital models by capturing the shape and appearance of real objects. Due to both scienti c and technological advances, low-cost 3D reconstruction is now widely used to reconstruct objects of reasonable geometric complexity using cheap acquisition hardware; however, it is unclear whether or not these devices produce suitable results to preserve cultural heritage artifacts. First, this paper goes over the general concept of 3D reconstruction and the main di erences between lowcost and general-purpose 3D reconstruction pipelines, these di erences are illustrated using a prototypical low-cost pipeline that has been used to reconstruct heritage artifacts. Then, we present the results of a survey conducted in order to investigate how existing low-cost 3D reconstruction approaches attempted to improve the results of their reconstructions, with an emphasis on the realistic rendering techniques they have used. Throughout the survey process, a categorization for low-cost 3D methodologies was proposed based on the scanning apparatus used by the approaches and other similarities between them. Finally, based on the surveyed studies and the results obtained with the prototypical pipeline, we conclude that it is possible to preserve heritage artifacts using low-cost approaches, granted that modern realism techniques are used to improve the appearance of the models.Key words: Low-cost 3D reconstruction; cultural heritage; digital heritage; survey. ResumoOs métodos de reconstrução 3D permitem a obtenção de modelos digitais através da captura da informação de forma e aparência dos objetos. Devido a avanços cientí cos e tecnológicos, técnicas de reconstrução 3D de baixo custo se tornaram amplamente utilizadas para reconstruir objetos com geometria razoavelmente complexa usando dispositivos de aquisição de baixo custo; no entanto, ainda é discutível a aplicabilidade desses dispositivos de baixo custo para preservação de artefatos culturais. Primeiramente, esse trabalho introduz a área de reconstrução 3D e discute as principais diferenças entre metodologias de reconstrução de baixo custo e metodologias de reconstrução de propósito geral, essas diferenças são ilustradas ao ser apresentado um protótipo de metodologia de baixo custo que foi utilizado para reconstrução de artefatos culturais. Posteriormente, são apresentados os resultados de um levantamento realizado a m de investigar como as propostas existentes de reconstrução de baixo custo visaram melhorar a qualidade das reconstruções geradas, com ênfase nas técnicas de renderização realista utilizadas. Ao longo da realização do levantamento, foi proposta uma categorização dos estudos investigados levando em consideração o aparato de escaneamento utilizado e outras similaridades. Ao m, com base nos estudos levantados e nos resultados obtidos usando a metodologia apresentada, conclui-se que é possível a utilização de metodologias de reconstrução de baixo custo para preservação de artefatos culturais, uma vez que sejam utilizad...

Poor data acquisition from low-cost cameras, such as low-resolution depth maps or high level of noise or point clouds generated with insufficient information from an object, limits the use of such cameras for heritage artifacts 3D reconstruction. This work proposes to improve this depth low-cost acquisition by using a new approach based on the Super-Resolution technique. The proposed approach has been applied to several artifacts of the Federal University of Bahia Museum of Archaeology and Ethnology (MAE/UFBA). As shown in the results, our approach improved the quality of point clouds generated from tested heritage artifacts. Results indicate that whenever artifact geometry is gained via our method there is actual reconstruction of detail or accuracy improvements, whereas a reduction in number of points of the clouds, if any, would indicate the removal of inconsistencies or noise from the input data without loss of detail.

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This work presents a new representation used as a rendering primitive of surfaces. Our representation is defined by an arbitrary cubic cell complex: a projection-based parameterization domain for surfaces where geometry and appearance information are stored as tile textures. This representation is used by our ray casting rendering algorithm called projection mapping, which can be used for rendering geometry and appearance details of surfaces from arbitrary viewpoints. The projection mapping algorithm uses a fragment shader based on linear and binary searches of the relief mapping algorithm. Instead of traditionally rendering the surface, only front faces of our rendering primitive (our arbitrary cubic cell complex) are drawn, and geometry and appearance details of the surface are rendered back by using projection mapping. Alternatively, another method is proposed for mapping appearance information on complex surfaces using our arbitrary cubic cell complexes. In this case, instead of reconstructing the geometry as in projection mapping, the original mesh of a surface is directly passed to the rendering algorithm. This algorithm is applied in the texture mapping of cultural heritage sculptures.