Organizing 8 Advantages and Limitations of Using Drone Point Clouds for 3D Recording of Cultural Properties

In the fields of preservation, repair, investigation, and public utilization of cultural properties, there is a strong desire to preserve the current condition as accurately as possible. Traditionally, information has been accumulated by combining photographs, measured surveys, drawings, and written records, but in recent years the use of point cloud data that can preserve shapes in three dimensions has spread, changing the very concept of recording. Among these methods, point cloud acquisition using drones has attracted attention as an efficient way to capture wide areas from above.

Cultural properties differ from ordinary buildings or civil engineering structures in many unique ways: preservation considerations, restricted access, complex shapes, the need to inspect roofs and high places, and the integrated understanding of surrounding terrain. For these reasons, drone point clouds, which can record widely from above, appear to be a promising option. On the other hand, the information required for cultural property records is not limited to the overall form. There is a lot of information—such as under-eaves areas and interiors, fine decorations, surface relief, and traces of aging—that is easier to grasp only from close proximity, so whether drone point clouds alone are sufficient requires careful consideration.

What matters in practice is not deciding whether to use drone point clouds based on intuition, but calmly organizing what they are good at and where their limits lie in the 3D recording of cultural properties. Understanding the basic fact that they are strong for wide-area recording and high-place understanding but weak for details and blind spots can greatly reduce mistakes in method selection. Conversely, introducing the technology based only on the impression that it produces visually attractive 3D data can lead to later problems with insufficient accuracy or missing records.

This article organizes the advantages and limitations of using drone point clouds for 3D recording of cultural properties into eight perspectives, to help practitioners make judgements. It explains from a field-oriented viewpoint so that cultural property managers, survey companies, measurement firms, and conservation and repair personnel can use it as a pre-introduction decision-making resource.

Table of Contents

• Why drone point clouds are gaining attention for 3D recording of cultural properties

• 1 Easy to record wide areas in a short time

• 2 Easy to grasp roof and high-place shapes

• 3 Easy to preserve surrounding terrain and spatial relationships together

• 4 Non-contact recording reduces site burden

• 5 Limits for fine shapes and unseen surfaces

• 6 Point cloud appearance does not equal required accuracy

• 7 Quality is easily affected by flight conditions and surroundings

• 8 Hard to be standalone; combination with other methods is often assumed

• How to make the most of drone point clouds in 3D recording of cultural properties

Why drone point clouds are gaining attention for 3D recording of cultural properties

Drone point clouds are gaining attention in 3D recording of cultural properties because they make it efficient to obtain spatial information that has been difficult to capture from the ground alone. Cultural properties include not only individual structures but also elements that become easier to understand from above: site elevation differences, stone walls and slopes, approach paths, gardens, surrounding terrain, and the arrangement of multiple buildings. By acquiring images from multiple directions from the air and using them to create three-dimensional data, cultural properties can be recorded as an entire space rather than as isolated objects.

In particular, roofs and high exterior parts of buildings are often difficult to grasp from ground-level photos or visual inspection alone. In cultural properties, roof shapes themselves can carry design value or structural characteristics, so the ability to record them is a significant advantage. Recordings that incorporate aerial viewpoints are also effective for situations where repeated capture of a certain area is needed, such as post-disaster condition assessment, pre- and post-repair comparison, and wide-area archaeological surveys.

However, being noteworthy does not mean drones are optimal for all cultural properties. 3D recording often requires both overall understanding and detailed recording, so it is necessary to delineate the areas where drone point clouds excel and where they do not. The important point is not to make a simple decision on whether to adopt the method, but to understand both advantages and limitations and to consider how the method fits into the overall recording strategy.

1 Easy to record wide areas in a short time

The most obvious advantage of drone point clouds is that they make it easy to record wide areas in a short time. In cultural property surveys, the targets are not always limited to a single building. There are situations where one needs to grasp the entire site, multiple structures, surrounding terrain, circulation routes, exterior features, stone steps, stone walls, and vegetation arrangements. In such cases, methods that can record from above all at once are a major strength.

Ground-based point-by-point recording methods are strong at capturing details but become time-consuming and labor-intensive over wide areas. Especially for cultural properties where it is necessary to piece together an overall picture from changing viewpoints, the ability to efficiently capture wide-area information can greatly affect the progress of the entire plan. Drone point clouds are valued for reducing on-site work time while leaving data in a form that makes it easy to review the overall composition afterward.

There are also circumstances in cultural properties that make it desirable to minimize on-site presence. At publicly open facilities, religious sites, sites with many visitors, or areas requiring consideration for nearby residents, prolonged work can increase the burden on the site. The ability to acquire wide coverage in a short time is not just an efficiency gain but also an operational advantage.

However, it is important not to confuse the fact that data can be acquired quickly with the fact that all necessary information will be captured. Being able to capture wide areas quickly is certainly a benefit, but if there are blind spots or recording omissions within that range, additional work will be required later. Therefore, this advantage should be understood as being particularly effective for the purpose of capturing the overall, large-scale picture.

2 Easy to grasp roof and high-place shapes

One reason drone point clouds are highly regarded in 3D recording of cultural properties is that they make it relatively easy to capture the shapes of roofs and high places. For cultural property structures, roof pitch, curvature, ridge alignment, upper composition, and exterior aspects that are difficult to see from surrounding viewpoints can be important information. These are areas where ground observation alone often has limitations; high-place work or distant viewpoints are required, increasing the barriers to recording.

With drone point clouds, multiple viewpoints at heights close to the subject can be secured from the air, making it easier to capture surfaces that are difficult to record from the ground. This advantage is particularly pronounced for buildings where the roof is a key part of the cultural value or for subjects with distinctive high-place ornamentation. Combining top views with oblique viewpoints also helps in grasping the overall three-dimensionality.

Roof and high-place information is also useful for initial decisions in preservation, repair, and maintenance. It makes it easier to visually assess where deformations or irregularities occur and how the overall fitment looks. For cultural properties where direct on-site inspection of upper parts is difficult, aerial recording is valuable as a means to first understand the overall composition.

That said, this advantage does not fully solve all roof and high-place recording issues. Deep under-eave interiors, overlaps of members, intricate ornaments, and shadowed areas may not be sufficiently visible even from the air. In other words, while drones are strong for capturing roofs and high places, it should be understood that this strength applies to the externally visible areas; detailed joinery and unseen backsides require other measures.

3 Easy to preserve surrounding terrain and spatial relationships together

The third advantage of drone point clouds is that they make it easy to record surrounding terrain and spatial relationships as a single entity. The value of cultural properties often lies not only in standalone buildings or remains but in the entire space where they are situated. This characteristic is very important in cultural property recording.

For example, in shrine and temple architecture, it may be significant to record not just the main hall but also the approach, stone steps, gate, site topography, and relationships with surrounding woodlands. For historic sites, the undulation of landforms, slope faces, traces of moat-like features, and positional relationships with surrounding facilities can be more important than individual remains. In gardens or groups of stone structures, recording the distances and elevation differences relative to the surroundings can make the spatial value of the cultural property more apparent.

Ground-based recording alone can make it difficult to grasp these spatial connections. Even if you obtain individual photographs or localized point clouds, additional work is needed to understand them from a bird’s-eye perspective. Drone point clouds capture wide areas as a continuous whole from the start, making it easier to record cultural properties without separating them from their surroundings.

This feature is also suitable for explanatory materials and stakeholder sharing. Those involved in conservation and repair, managers, administrative staff, and researchers can more easily understand the relationships between the subject and its surroundings without visiting the site. Because cultural properties often involve people in different roles, the practical value of being able to share the overall picture is high.

However, being able to capture wide surroundings does not mean that all values are fully recorded. Parts hidden by vegetation, shaded steep slopes, backsides of structures, and connections to interior spaces may be insufficiently recorded solely from above. Therefore, this advantage should be understood as meaning that drone point clouds are strong for recording cultural properties in a broad contextual sense.

4 Non-contact recording reduces site burden

In cultural property recording, minimizing the burden on the subject is important. The fourth advantage is that drone point clouds are easy to acquire non-contact and thus can reduce on-site burden. Cultural properties are often aged, and proximity, installation, or use of scaffolding can be constrained. For that reason, the ability to acquire wide coverage without directly touching the subject is a major benefit.

For example, even when checking high places, it may not be necessary to prepare large-scale equipment each time. In places where access is restricted, on terrains where scaffolding is difficult to set up, or for subjects where proximity poses risks, it is possible to record while keeping a certain distance. This aligns well with cultural property protection principles, and is particularly meaningful at sites that require cautious preservation approaches.

It also reduces the burden on workers. Trying to confirm high places or grasp wide areas from the ground can be time-consuming and physically demanding. In cultural property environments with severe on-site conditions, being able to obtain necessary information while reducing physical and time burdens is important not only for measurement quality but also for continuity of work. This non-contact nature and mobility are a significant advantage, particularly when multiple locations must be recorded in a short time.

However, being non-contact is not万能. The trade-off for not touching the subject is that you can only capture what is visible. Cultural properties often have surface conditions, joints, backsides, interiors, and deep shadows that are difficult to confirm without close proximity. Therefore, while the ability to capture wide areas non-contact is a major advantage, complementary methods may be required depending on the types of information needed.

5 Limits for fine shapes and unseen surfaces

Now turning to limitations. The fifth point is that drone point clouds have limits in recording fine shapes and unseen surfaces. In 3D recording of cultural properties, not only the overall shape but also surface relief, fine decorations, cracks and defects, joints, under-eaves, interiors, and backsides—information that is difficult to grasp without close-range observation—can be important.

Drone point clouds excel at capturing areas visible from above or around the exterior, but parts that are not visible are fundamentally difficult to obtain. Deep under-eave interiors, depths behind overlapping members, shadows cast by trees or walls, indoor spaces, and the backs of narrow passageways cannot be adequately captured from aerial viewpoints alone. Because cultural properties often have complex configurations and unseen surfaces with value, this weakness cannot be overlooked.

There are also limits from the perspective of recording fine detail. Cultural property investigations often target minute undulations of ornamentation, tool marks, wear, cracks, and slight deformations, which overall-oriented drone point clouds may fail to capture. Even if a three-dimensional model is visually created, if the necessary fine-detail information is lacking, it will be insufficient for practical tasks like investigation or repair.

If one adopts drone point clouds without understanding these limits, it is easy to be misled into thinking that having an overall point cloud is sufficient for cultural property recording. In reality, overall grasp and detailed recording are separate challenges. Drone point clouds are strong in the former and require additional measures for the latter. That means for projects needing full-detail recording, drone point clouds should not be used alone but planned in combination with close-range ground recording or other measurement methods.

6 Point cloud appearance does not equal required accuracy

The sixth point is that the visual quality of a point cloud and whether it meets the accuracy required for practical use are not the same. This applies to 3D recording in general, not only to drone point clouds, but it is especially important for cultural properties. This is because the meaning of required accuracy varies by purpose in cultural property recording—drawing production, condition comparison, preservation and repair planning, research, explanatory materials, etc., each demand different levels of precision.

Even a point cloud that appears dense and well-formed does not necessarily have sufficient reliability for dimensional confirmation. Conversely, if the purpose is overall understanding, somewhat coarse detail may still be useful. In other words, the value of a point cloud should be judged on whether it provides the reproducibility needed for the intended use, not on its visual appeal.

Conditions also differ by component within cultural properties. Roof surfaces may be captured relatively well while some parts of façades become unstable due to shading, areas near trees produce a lot of noise, and monotonous walls reduce shape reliability. Even if overall three-dimensionalization is achieved, important parts alone may lack sufficient accuracy. These differences are hard to judge by appearance alone, so checks according to intended use are indispensable.

Furthermore, required accuracy in cultural property surveys is not uniform. The level demanded for grasping the whole site and for producing detailed drawings of specific parts differs. Therefore, when evaluating drone point clouds, do not apply a single standard to the whole dataset; organize what uses the data can withstand. It is important to decide based on whether the data is sufficient for the intended application, not merely on how pleasing it looks.

7 Quality is easily affected by flight conditions and surroundings

The seventh point is that the quality of drone point clouds is heavily influenced by flight conditions and the surrounding environment. Cultural property sites are not always open, easy-to-shoot environments. They are often located in varied and complex conditions—at the base of mountains, in forests, in residential areas, within religious precincts, along tourist routes, or on narrow streets. These differing site conditions directly affect point cloud quality and acquisition feasibility.

For example, in areas with unstable wind, stable flight becomes difficult and image quality suffers. Strong backlighting, deep shadows, or dappled sunlight can make surface information unstable. Sites with many trees, power lines, or surrounding structures may prevent shooting from necessary angles, complicate flight path planning, and increase blind spots. Because cultural properties frequently sit in such constrained sites rather than open spaces, more cautious decisions are required than for general aerial photography.

High visitor traffic is another cultural property-specific condition. Consideration for worshippers, sightseers, managers, and nearby residents is necessary; flight timing, route control, and site operation all affect quality. Trying to rush to finish quickly may leave necessary viewpoints lacking or insufficient confirmation. Conversely, a well-planned schedule with adequate time tends to stabilize both safety and quality.

In short, drone point cloud results are not determined solely by equipment and processing skills. How accurately one reads the site conditions and designs a feasible flight and acquisition plan has a major impact. Since both the value of the subject and the surrounding environment often make acquisition conditions difficult at cultural properties, it is necessary to plan with these limits in mind.

8 Hard to be standalone; combination with other methods is often assumed

The eighth point is that drone point clouds are difficult to use as a standalone solution in 3D recording of cultural properties; combination with other methods is often the premise. This is both a limitation and an important indicator of correct usage.

Drone point clouds are strong at capturing overall shape, roofs, high places, site composition, and surrounding terrain, but weak at fine details, interiors, blind spots, and parts needing close-range confirmation. Cultural properties require both types of information. In practice, it is natural to combine aerial overall recording with ground-based detailed recording. The usual approach is to capture the overall framework with drone point clouds and supplement missing parts with ground-side methods—this is realistic for many field situations.

Failing to understand this premise of combination can lead to excessive expectations of drone point clouds. If people assume that because the whole is captured, the details are sufficient, deficiencies will emerge at the repair planning or detailed investigation stage. Conversely, if roles are defined from the start, it becomes clear which parts will be taken by drones and which will be supplemented by other methods. This reduces duplication and omissions on site.

Also, creating positional references is important in cultural property recording. To reuse an overall point cloud later, it is desirable to clearly understand the correspondence with the actual site. Considering not only aerial point clouds but also on-site positional verification and continuous coordinate management increases the value of the records. In other words, treat drone point clouds not as a finished standalone product but as one layer within the overall cultural property recording.

In this sense, the limitations of drone point clouds are less defects than signs of appropriate application. Instead of trying to do everything with a single method, using drones as a method strong in overall recording makes 3D recording of cultural properties more stable.

How to make the most of drone point clouds in 3D recording of cultural properties

As we have summarized, the advantages of using drone point clouds for 3D recording of cultural properties lie in their ease of recording wide areas quickly, capturing roof and high-place shapes, preserving surrounding terrain and spatial relationships together, and reducing on-site burden through non-contact acquisition. These are major advantages for viewing cultural properties as spatial entities. Drone point clouds are a powerful option, especially for overall grasp and wide-area recording.

At the same time, the limitations are clear. They are weak at capturing fine shapes and unseen surfaces, visual quality does not guarantee the required accuracy, and the results are heavily influenced by flight conditions and surrounding environments. Moreover, cultural property recording rarely concludes with a single method: combining drone point clouds with ground-side recording and positional reference frameworks usually produces records that are practical for real-world use. In short, drone point clouds are not a万能 answer but a method that should be used with a clear role within the overall recording strategy.

To avoid practical failures, first clarify what you want to preserve. The value of drone point clouds varies depending on whether you aim to record overall layout, roof shapes, surrounding terrain, or repair comparisons. Actively use drones for projects suited to overall recording, and position them as supplementary tools where details and blind spots are important. If you can make this distinction, method selection will be more accurate.

Also, to make 3D records of cultural properties more practical, consider not only the point cloud itself but how to handle on-site positional information. For surveys covering large sites or multiple targets, being able to accurately identify where each record was made contributes to ease of continued management and re-survey. If you want to operate a drone-based wide-area 3D recording system along with on-site positional checks and continuous coordinate management, combining technologies such as iPhone-mounted GNSS high-accuracy positioning devices like LRTK can be effective. If you do not want drone-based wide-area 3D records to end as one-off deliverables but rather want to build a recording foundation that supports future comparisons and maintenance, consider designing the overall system to include such positional information mechanisms to make the records more reusable and practical.