The aim of this work is to identify an efficient pipeline in order to build HBIM (heritage building information modelling) and create digital models to be used in structural analysis. To build accurate 3D models it is first necessary to perform a geomatics survey. This means performing a survey with active or passive sensors and, subsequently, accomplishing adequate post-processing of the data. In this way, it is possible to obtain a 3D point cloud of the structure under investigation. The next step, known as “scan-to-BIM (building information modelling)”, has led to the creation of an appropriate methodology that involved the use of Rhinoceros software and a few tools developed within this environment. Once the 3D model is obtained, the last step is the implementation of the structure in FEM (finite element method) and/or in HBIM software. In this paper, two case studies involving structures belonging to the cultural heritage (CH) environment are analysed: a historical church and a masonry bridge. In particular, for both case studies, the different phases were described involving the construction of the point cloud and, subsequently, the construction of a 3D model. This model is suitable both for structural analysis and for the parameterization of rheological and geometric information of each single element of the structure.

The aim of this study is to evaluate the degradation of the accuracy and quality of the images in relation to the TIFF format and the different compression level of the JPEG format compared to the raw images acquired by UAV platform. Experiments were carried out using DJI Mavic 2 Pro and Hasselblad L1D-20c camera on three test sites. Post-processing of images was performed using software based on structure from motion and multi-view stereo approaches. The results show a slight influence of image format and compression levels in flat or slightly flat surfaces; in the case of a complex 3D model, instead, the choice of a format became important. Across all tests, processing times were found to also play a key role, especially in point cloud generation. The qualitative and quantitative analysis, carried out on the different orthophotos, allowed to highlight a modest impact in the use of the TIFF format and a strong influence as the JPEG compression level increases.

Remote-pilot aircraft are developing very rapidly and their potential in the various fields is often still to be fully investigated. The possibility to fly over the areas to be surveyed without the need to access the areas themselves makes the use of UAVs in some cases certainly preferable for safety reasons, as has already been tested for the management of postdisaster areas. Waste landfills are small sites where contact with waste itself must be limited and scientific experimentation on surveying this specific type of site is currently limited. The results obtained in other types of sites or infrastructures are not automatically applied to waste landfills due to the specific geometrical characteristics and texture of the images that can be obtained at sites like these. In this work, a test on an exhausted landfill has been carried out with attention to the accurate survey of a large number of control points necessary for a correct assessment of the final geometric accuracy. The use of ground control points and checkpoints has allowed the separate evaluation of precision and accuracy, which are very close to those obtained with the most common methods for these sites, such as laser scanning and total stations.

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The management of Cultural Heritage (CH) requires increasingly efficient, simple and shareable tools, methods and knowledge. In this environment, a suitable procedure was developed to transform the point cloud, generated by geomatics surveys, into parameterized objects. In order to obtain an object with precise geometric and physical characteristics, a three-dimensional modelling software (Rhinoceros) was used. This software, using the tools and specific plugins, has allowed the parameterization of objects. In particular, the use of the Grasshopper plugin allowed a two-way transformation of the objects between the modelling software and the BIM software (Revit). As a result, any changes to the model made in Rhinoceros were automatically made in Revit and vice versa. The paper shows the potentiality, simplicity and efficiency of the developed method in order to perform the scan-to-HBIM process. This approach was applied to a religious building, located in Italy, belonging to the Cultural Heritage.