High-precision 3D heritage capture in challenging environments

A remarkable digital heritage initiative recently took shape in the Romanian city of Cluj-Napoca: the high-precision 3D documentation of the Casino, a sophisticated early-twentieth-century landmark that embodies the city’s prosperity and cosmopolitan spirit. The project, executed by SkyGrid in collaboration with CHCNav, demonstrates how mobile laser scanning workflows can streamline heritage capture in complex environments without compromising on geospatial accuracy or architectural detail, according to GIM International.

In the Romanian city of Cluj-Napoca, the cultural heart of Transylvania, centuries of architectural identity blend seamlessly with a thriving innovation economy. Shaped by Roman foundations, mediaeval growth and Austro-Hungarian refinement, the historic centre remains a focal point of civic life and a defining backdrop for residents and visitors. As development accelerates, preserving this architectural character has become a growing priority.

SkyGrid, a Romanian surveying solutions provider with long-standing technical expertise, initiated a project to demonstrate how handheld laser scanners – in this case CHCNAV’s RS10 system – can be applied in a real-world heritage setting, and which benefits they offer. In Cluj-Napoca’s central park, the Casino and its surrounding architectural features, including a fountain and ornamental façades, offered the ideal test environment. The combination of rich ornamentation and height differences created the level of surveying challenge required to showcase the system’s strengths.

The Casino’s presence within a vibrant city park added an additional layer of operational complexity. Data collection had to respect the ongoing activities of visitors, sports enthusiasts and cultural event organizers. Moreover, the site featured areas where tall trees, archways and covered terraces obstruct GNSS reception. Such environments often significantly slow down traditional survey methods or require additional instruments and time-consuming alignment procedures. In contrast, the goal of this project was to demonstrate a seamless workflow: capturing a culturally significant building quickly, unobtrusively and completely, while maintaining consistent positional accuracy from start to finish.

A technology shift is underway

For generations, the capture of built heritage has relied on static terrestrial laser scanning. While extremely precise, that methodology requires repeated instrument setup, strong line-of-sight conditions and extensive post-registration. In public urban spaces, this translates into lengthy acquisition schedules and the risk of disruptions to everyday activity.

The RS10 represents a shift away from the paradigm as described above, offering a different choice for projects of this nature. It integrates GNSS RTK, visual SLAM and Lidar into a single, handheld platform. The result is a single, unified coordinate reference that extends across indoor and outdoor environments without the need for additional control points, loop closures or manually merged datasets.

Efficiency redefined

In the Romanian project, GNSS RTK provided sub-5cm positioning accuracy outdoors, directly anchored in the country’s national coordinate system. In areas where the satellite visibility dropped, such as beneath terrace roofs or near mature trees, the device relied on visual SLAM to maintain a stable trajectory. This proved to be very successful. Throughout, high-density Lidar acquisition ensured that even the finest ornamentation was recorded at high resolution. For the operator, this meant simply walking preplanned routes while the device continuously georeferenced and recorded the geometry of façades, arcades and interior details.

The operational benefits became immediately apparent in the field. A typical survey day followed a short and highly efficient workflow: a rapid initialization and connection to the local GNSS RTK network, followed by route planning based on expected transitions between open-sky and signal-compromised environments. The scanning itself required no stoppages, no blocked-off zones and no tripod relocations, reducing inconvenience for park visitors and ensuring a discreet presence in a public space. The mobile scanning approach contributed to the urban atmosphere rather than being a visual disturbance.

Ready-to-use results

What traditionally might well have taken multiple days using static equipment was completed in hours. A particularly revealing test involved the portion beneath the terrace roof: a narrow, low-visibility zone that normally demands careful scanner stationing and poses a risk of shadowed geometry. Here, the operator just walked beneath the structure while the system autonomously recorded and localized the scan. This efficiency did not come at the expense of completeness; the complex ornamental details of this structure were captured with remarkable consistency from top to bottom.

The project produced a dense, colourized and fully georeferenced point cloud that could immediately serve as the authoritative dataset. On top of this, the team developed detailed three-dimensional models for visualization and volumetric studies, along with orthophotos, plans, sections and façade drawings to support architectural analysis.

Aligning with a European trend

Across the whole of Europe, the digital documentation of built heritage is accelerating. Climate stress, increasing tourism pressures and the need for informed restoration workflows are driving new expectations for precise, accessible records of historical assets. A shift is also taking place from reactive documentation to proactive conservation. Instead of scanning only after a visible problem emerges, high-frequency digital inventories enable continuous assessment. Digital twins, created efficiently and with topographic accuracy, are allowing urban planners and conservation authorities to make data-informed decisions about preservation, reuse and adaptation.

The future of heritage surveying in Europe lies in scaling precision. Projects that once seemed too costly or time-consuming become feasible when mobility and absolute accuracy are combined in a single workflow. That opens the door to broader regional programmes that ensure culturally important structures are documented before their condition changes irreversibly. Romania, with its wealth of castles, fortifications and architectural landmarks, stands to benefit significantly from scalable technologies that reduce the cost and time needed to capture complex structures.

Although municipal authorities were not directly involved in the planning phase, all deliverables from the Cluj-Napoca project have been made available for future restoration work or urban planning studies. The Casino building is not only an architectural treasure but also a cultural venue that regularly hosts exhibitions, performances and public gatherings. A precise digital representation supports that role. Restoration architects can evaluate existing conditions with confidence, and heritage authorities gain a baseline for long-term monitoring. In addition, the data is well suited to educational initiatives or virtual tourism experiences that promote local identity.

Technology that extends far beyond heritage

The applicability of this workflow extends well beyond cultural projects. The same reality capture capabilities that proved valuable in Cluj-Napoca’s central park are being explored for infrastructure inspection, as-built verification in construction, and environmental applications such as vegetation mapping or biomass analysis. As more industries adopt spatially aware asset management, the demand for fast and accurate 3D information will only continue to grow.

Crucially, the method demonstrated in Cluj-Napoca integrates smoothly into multidisciplinary workflows. The dataset is ready for architects, engineers, GIS analysts and decision-makers without time-consuming transformation or alignment. That interoperability bridges the gap between the surveying domain and a wider user base.

The Cluj-Napoca Casino project demonstrates that high-precision heritage documentation no longer requires long field days, complex setups and extensive registration workflows. By merging the strengths of GNSS RTK, visual SLAM and Lidar into a unified solution, the RS10 allowed SkyGrid’s surveyors to create a complete and georeferenced model of a complex structure rapidly and with confidence.

In a city in where history and innovation increasingly converge, reality capture technologies are helping to ensure that cultural heritage remains accurately documented, easily accessible and ready for future analysis. As urban modernization continues, the capacity to record and understand the architecture that is shaping local identity will remain essential. Thanks to this demonstration project, Cluj-Napoca now has a detailed digital representation of one of its iconic landmarks, strengthening the foundation for future preservation efforts and supporting the continued appreciation of the city’s rich architectural legacy. Moreover, as Cluj-Napoca continues to grow, the accurate representation of its iconic architecture can play a role not only in conservation, but also in shaping urban policy and planning decisions.

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