## 2 Materials and Methods
### Data  
This study utilized data made accessible as part of the national surveying and cartographic resource, encompassing orthophotos and comprehensive information on the geometry of buildings. In alignment with the openness policy adopted by the GUGiK, these data are publicly available and free of charge for acquisition [34].  
The data may be accessed and extracted via the web-based National Geoportal application [35], which allows for straightforward access for both individual and institutional users. Alternatively, the data may be extracted via an automated method using web services that comply with international standards, such as WFS, which is designed to provide vector data, and WCS, which allows raster data to be downloaded. The utilization of open standards, such as WFS and WCS, endows the system with a substantial degree of flexibility, thereby facilitating seamless integration with a diverse array of spatial data sources, irrespective of geographical location or technological heterogeneity across different regions. The implementation of these open standards ensures compatibility with a comprehensive spectrum of geospatial databases, encompassing both national and international databases. This integration enhances the system's potential, facilitating easy adaptation to different regional specifications and requirements, which is crucial in a global context.  
The geometric data of buildings included in the Land and Building Register database are recorded on the basis of land surveys. These measurements are taken along the contours of the buildings, at their point of contact with the ground. It should be noted that the dataset does not include information on the geometric roof details, which often extend beyond the building outline. The orthophotos used are studies with a high fixed spatial  
Figure 1: Study area in Głusk Community, Lublin Poviat, Lubelskie Voivodeship, Poland (source: author’s own elaboration).  
resolution (pixel value of 0.05 m), providing precise spatial information about the actual land use. The use of an orthophotomap at this resolution facilitates the detection of roof details, including edges, chimneys, and skylights, with a high degree of precision. The georeferenced accuracy of such maps is generally 10-20 cm, enabling the precise rendering of roofs. The spatial data acquired are compiled in the CS92 system (EPSG: 2180).  
It is imperative to underscore the limitations of orthophotos, which provide rudimentary information about roof geometry. Primarily, their two-dimensional nature hinders the accurate representation and recognition of complex roof forms. Secondly, the use of orthophotos as a reliable source for roof recognition is questionable. Future research should focus on integrating these data with more advanced sources to enhance their accuracy and utility. The integration of ALS LiDAR data will facilitate the creation of precise 3D models of roofs and enhance the discernment of intricacies. The utilization of oblique images will enable the observation of roofs from an alternative perspective, thereby supporting the precise identification of shapes, details, and proportions.