Surveyors from BUT save cultural monuments
Precise measurements, laser scanning, information modelling and visualisation using the tools of a game development environment will enable the gentle reconstruction of the listed Maxmilian Court in the Podzámecká Garden in Kroměříž. Modern methods solve the problem of insufficient or completely missing documentation of historical buildings, which is known to all builders.
There are more than forty thousand immovable cultural monuments in the Czech Republic, over seven hundred of them are on the endangered list. Researching old buildings is an important part of understanding the life and thinking of our ancestors and the maturity of society. Digitisation and advanced technologies are making the work of conservationists easier and faster.
Producing documentation of listed buildings in a comprehensive digital form is an important step in the process of preserving cultural heritage, and enables as much information as possible about immovable cultural monuments to be preserved for future generations. The creation of a Building Information Model (BIM) begins with precise data collection. The BIM then serves as the basis for drawing up the project documentation for the individual building professions during the reconstruction of the building.
The documentation of monuments is complicated not only by the lack of original drawings, but also by the characteristic elements of particular historical styles that are not easily documented in a standard way. Ancient buildings are characterised by specific constructions such as vaulted ceilings, non-vertical walls in the sense of, for example, a tapering thickness of masonry with increasing storey and generally less subtle finishes of surfaces, where, for example, it is not possible to speak of the flatness of earthen floors or stonework with regard to current standards.
"Accuracy of measurement is crucial for historic buildings, as their form structure is much more varied than that of modern buildings. The object is geometrically oriented by laser scanning and then processed into a so-called point cloud. We relate this to a binding coordinate and height system. Using information modelling methods, we create a model of the object and fine-tune the visualisations in the tools of a game development environment," explains the measurement and recording procedure, Michal Kuruc, a surveyor from the Faculty of Civil Engineering at Brno University of Technology. Surveyors are responsible for collecting accurate data.
The research team used a so-called total station, which simultaneously measures angles, lengths and elevations, satellite equipment for determining the spatial position of points and a laser scanner to measure the Maxmilian Court. Using the point cloud, they then generated a spatial model that describes the geometric shape and layout of the building in question (walls, floors, windows, doors, staircase, roof, roof, etc.) and the individual elements of the building's technical equipment (sanitary facilities, lighting fixtures, heating, fire extinguishers, etc.).
Gaming for designers
The digital modelling of old buildings also requires the enrichment of the non-geometric properties of the elements that make up the model. It is also necessary to take into account the often unique details of complicated shapes and surfaces. Professionals therefore have to create these special features for complex BIM, as none of the commonly used software includes them in their libraries.
"Characteristic decorative elements that are also very non-standard are the cow sculptures on the building. To record them accurately and preserve their historical value, we decided to create a detailed mesh model (triangular mesh) for each statue from a point cloud," Kuruc points out one of the biggest pitfalls in modelling.
The BUT surveyors used the Unreal Engine environment for the final modelling and BIM validation. Gaming tools allow for greater interaction with the digital world (in our case, the BIM model), namely more realistic visualizations compared to technical CAD/BIM applications, such as a fly-through or walk-through of a building, displaying information about elements, adding realistic materials or artificial lighting. The output from a game development environment does not have to be just visualisation in the form of images, it can also be a video sequence or a desktop application, or an application for virtual reality glasses. The documentation of the actual construction is followed by the visualisation of the model, which makes the historical value of the Maximilian Court building stand out. The researchers created a scene with a custom BIM model and surroundings, including surfaces and vegetation, as well as realistic materials and impressions of defects on the facades and columns to ensure that the final appearance matches the actual condition of the building.
Modern technology and its rapid development are opening up new possibilities even in fields where this was previously almost unimaginable. Experts from the Faculty of Civil Engineering now want to focus on the implementation of discipline-specific data structures to make the gaming environment more usable not only for gaming but also for technical applications.
Maximilian's Courtyard (or Hubertcentrum) forms part of the famous Podzámecká Garden in Kroměříž. It was built in 1844 and 1845 by Archbishop Maximilian Josef Sommerau-Beckh according to a design by the architect Antonín Arche as a model farm building for the needs of the archbishopric. It was a modern dairy and cowshed, but in the sense of an English ornamental farm or a French ferme ornée, combining beauty with purpose, aesthetic function with economic function. Over time, the site was extended to include two pavilions at the corners of the courtyard, creating a cour d'honneur and giving the building a more noble character.
|Mgr. Almíra Pitronová