7 Precautions to Avoid Regret When 3D Scanning Gravestones

3D scanning of gravestones is a technique that can be used in a variety of practical ways, such as recording and preserving shapes, comparing conditions before and after repairs, checking the legibility of inscriptions, creating drawings, and considering the production of replica prototypes. In recent years the range of applications for three-dimensional data has expanded, and for practitioners responsible for the management, conservation, investigation, and documentation of gravestones, 3D scanning has become one of the methods worth considering on site.

On the other hand, 3D scanning of gravestones is not something that can be done satisfactorily just by pointing equipment at the site and taking measurements. If you do not clarify in advance the condition of the subject, the installation environment, the required level of accuracy, the format of the deliverables, coordination with stakeholders, and so on, you may not obtain the expected data, which can lead to re-measurement or operational issues. In particular, gravestones are often installed outdoors for many years, and conditions that make measurement difficult—such as weathering, missing parts, reflective surfaces, narrow working spaces, and surrounding obstacles—tend to coincide.

In this article, we outline and explain seven precautions that project staff should be aware of beforehand to avoid regrets when 3D scanning gravestones. We provide a detailed overview of the entire process—from on-site preparation to data utilization—so this will be useful both to people considering a gravestone 3D scan for the first time and to those who have previously taken measurements but were unable to make full use of them.

Table of Contents

• Why confirming points to note is important in 3D scanning of gravestones

• Note 1: Be clear from the outset about why you are performing the 3D scan

• Note 2: Do not make the required accuracy and recording range ambiguous

• Note 3 Do not overlook the measurement difficulty caused by the material and surface condition of the gravestone

• Note 4: Do not overlook the local environment and shooting conditions

• Point 5: Do not neglect to coordinate in advance with administrators and stakeholders.

• Point 6: Decide in advance the format of the deliverable data and how it will be used.

• Point 7: Don't stop at measurement; consider storage and updates.

• Summary

Why It’s Important to Check Precautions When 3D Scanning Gravestones

At sites considering 3D scanning of gravestones, it's important not only whether they can simply be captured in three dimensions, but also the level of quality, the extent of coverage, and the purposes for which the data can be used. If these points are left ambiguous and you proceed, even if the work itself is completed you can encounter problems later such as "the information we wanted wasn't captured," "the depth of the inscriptions can't be determined," "the relationship to the base wasn't preserved," or "the accuracy wasn't sufficient for planning repairs."

Gravestones are not uniform in shape like typical industrial products. They are a subject in which many factors affect data quality: differences in texture due to stone type, years of weathering, moss and dirt, moisture, a mix of shade and direct sunlight, and work constraints within narrow grave plots.

Furthermore, in practical work involving gravestones, sometimes it is sufficient to know only the shape, while other cases require assistance reading inscriptions, assessing cracks, providing baseline data for repair design, or long-term use for record preservation; depending on the purpose, the required resolution and processing methods vary greatly.

Therefore, when 3D scanning gravestones, it can be said that the quality of the measurement plan—rather than the mere feasibility of the measurement itself—determines the outcome. A single mistaken judgment on site can lead to rework in later stages and insufficient explanation to stakeholders, greatly increasing both time and effort. That is why it is important to organize the precautions in advance and proceed with a clear view of the objectives, conditions, deliverables, and operations.

Key Point 1: Clearly define at the outset why you are performing the 3D scan

The first thing to confirm is the purpose of 3D scanning the gravestone. This may seem basic, but it is actually the aspect most likely to lead to regret. If you proceed with an unclear purpose, you may end up producing data that is heavier than necessary or, conversely, lacking important details, resulting in deliverables that are unusable in practice.

For example, if the primary purpose is to record the current condition of a gravestone, it is important to capture its overall shape and installation status. In that case, recording not only the gravestone itself but also the positional relationships with the surrounding foundation, outer fence, and pathways will make it easier to understand the site conditions later. On the other hand, if the purpose is to assist in reading the inscribed characters or to check surface deterioration, capturing the overall shape alone is insufficient; a measurement plan capable of recording the fine surface undulations is necessary. Furthermore, if the data will be used as material for considering repairs or restoration, a level of data density and consistency suitable for design decisions is required, including the boundaries of missing parts, tilting, seams, and the condition of joints.

In this way, even with the same "3D scan of gravestones," the required deliverables can differ greatly. However, in the field it's easy to decide to "just capture three-dimensional data for now" without clarifying the objectives, and that often becomes a source of regret. Having the data itself can be reassuring, but it is meaningless if it does not match its intended use.

In practice, it is important to first clarify who will use it and for what purpose. Whether administrative staff will use it for asset register maintenance, maintenance personnel for comparing deterioration, design staff for creating drawings, or it will be preserved long-term for research purposes, the required specifications will differ. Simply aligning this at the outset can greatly reduce unnecessary on-site measurements.

Also, when there are multiple objectives, you need to establish priorities. Deciding in advance whether to prioritize overall shape, surface information, textual information, or the surrounding environment will help prevent omissions during on-site capture. To avoid regrets, it is important to regard 3D scanning not as a technical topic but as a means of acquiring information tailored to your business objectives.

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Note 2: Do not make the required accuracy and recording range ambiguous

One common mistake in 3D scanning of gravestones is beginning measurements without concretely defining the required accuracy and the extent of recording. Because three-dimensional data can be made to look convincing visually, it may seem sufficient at first glance. However, when you later try to use it for dimensional checks or comparative verification, it is often found that the necessary level of detail is lacking.

The first thing to consider is how much detail needs to be recorded. The required level varies depending on whether it is sufficient to know the overall dimensions of the gravestone, whether you want to see the depth and contours of the inscriptions, or whether you need to capture surface warping and areas of loss. Capturing only the overall shape may be adequate, but it can lack sufficient information to assist in reading weathered characters. Conversely, aiming for excessively fine capture can increase data volume and make processing and viewing slow.

The same applies to the scope of recording. If you do not clearly define whether the subject is only the gravestone itself or also includes the base, the incense burner, the perimeter fence, and the surrounding ground, deficiencies will arise later such as “the installation conditions are unknown” or “the surrounding information necessary for considering relocation or repair is lacking.” In particular, because gravestones are often managed in relation to their surroundings rather than as standalone objects, defining the scope too narrowly makes practical use difficult.

Even more important is whether an absolute position is required. Depending on whether you intend to keep it as a standalone three-dimensional model or store it tied to site coordinates, the way you establish on-site reference points and the approach to coordinate management will differ. If you plan to compare across multiple time periods, overlay it with other materials, or link it with management drawings, you cannot take the handling of position lightly. If you perform measurements without deciding this, you may end up with an isolated model that cannot be connected to other data later.

To avoid regrets, it is effective to organize, before on-site work, the necessary dimension-check items, comparison targets, the departments that will use the data, and the viewing environment. Because a 3D scan of a gravestone can capture a large amount of information, it is important to define specifications that are neither excessive nor insufficient for the intended purpose. Rather than creating visually pleasing three-dimensional data, you need to base your approach on producing data that can be used in downstream processes.

Note 3: Do not overlook the measurement difficulty caused by the material and surface condition of gravestones

Gravestones are made of stone and therefore appear to be hard, stable subjects, but in reality the difficulty of 3D scanning can vary greatly depending on the material and surface condition. If this point is overlooked, even when it seems the data were captured without problems on site, the data can become difficult to use during processing due to many gaps and noise.

First, what you should be aware of are differences in surface reflectivity and texture. Tombstones with many polished surfaces can become strongly reflective depending on how light hits them, which can make surface information unstable. Conversely, surfaces that are rough due to advanced weathering may be easier to capture in terms of shape, but when there are many chips and erosion it can be difficult to judge how much should be considered the original form. In addition, stones that are wet, surfaces with moss or dirt attached, and areas with efflorescence or discoloration can be difficult to capture uniformly.

Care must also be taken when capturing inscriptions. There are many cases where 3D scanning is performed for the purpose of reading characters, but if the carved characters are shallow or the contours have been eroded by weathering, simply measuring the whole object may not yield sufficient information. In particular, gravestones may have characters or records carved not only on the front but also on the sides and back, and measurements focused only on the front can miss important information.

Handling cracks and missing parts is also important. From the perspective of repair and archival recording, accurately capturing damaged areas is required, but fine cracks and minute steps may or may not be visible depending on measurement conditions. Therefore, if the objective is to assess damage, you need to distinguish between what is confirmed by on-site visual inspection and what you intend to verify with 3D data. Trying to complete everything using only three-dimensional data can create a large gap between expectations and reality.

In practice, before measurement it is important to thoroughly inspect the condition of the target gravestone and determine which surfaces have what characteristics and which parts should be prioritized for capture. If necessary, confirm in advance whether cleaning is possible, the effects of wetness, and coverage by surrounding vegetation. For 3D scanning of gravestones, do not be reassured simply because the subject is stone; it is safer to regard the surface condition as the factor that will determine success or failure.

Caution 4: Do not underestimate the local environment and shooting conditions

3D scanning of tombstones is strongly affected not only by the object itself but also by the on-site environment. In outdoor cemeteries, many conditions overlap—weather, sunlight, surrounding trees, adjacent gravestones, pathway width, and visitor flow. If these are underestimated, the measurable range narrows, required angles cannot be secured, and as a result data gaps and quality degradation occur.

One typical factor is lighting conditions. When direct sunlight is strong, reflections and shadow contrasts on the gravestone surface increase, which can make it difficult to capture the geometry reliably. Conversely, in environments that are too dark, image-based processing may struggle to detect feature points. Because many areas of a gravestone appear relatively simple in shape, alignment can become unstable under conditions where fine surface details are hard to capture. Regardless of the measurement method, it is important to choose times when on-site conditions are stable.

Next, there are problems with the work space. Gravestones are often densely arranged, making it difficult to get around them not only from the front but also from the sides and rear. When adjacent objects are close, you may be unable to capture the desired angles, resulting in increased shadowed areas and missing parts. Furthermore, if the footing is unstable or there are many level changes, it becomes difficult to maintain a consistent distance and posture for measurement. Forcing work on site not only increases the chance of data omissions but also raises safety risks.

Reflections and other visual intrusions from the surrounding environment should not be underestimated. If offerings such as flowers and food, potted plants, fallen leaves, fabrics, etc. are covering part of a gravestone, the correct shape cannot be accurately captured as-is. In some cases these can be removed during post-processing, but if the target surface is concealed the original form cannot be obtained. Therefore, it is important to confirm before work how much can be cleared on site and which items may or may not be touched.

Weather conditions also have a direct impact on the results. After rain or on days with high humidity, the appearance of the stone surface changes, making it more susceptible to reflections and color unevenness caused by wetness. On windy days, nearby vegetation and offerings can move and become sources of noise. For 3D scanning of gravestones, designing measurement conditions that include the site environment as well as the object specifications helps prevent regret. Instead of assuming you can deal with issues on the spot, it is important to regard the site conditions themselves as part of the quality of the finished deliverable.

Precaution 5: Do not neglect prior coordination with administrators and stakeholders

3D scanning of gravestones is not just a technical task; because of the nature of the subject, consideration for and coordination with relevant parties is extremely important. If this is taken lightly, even if there are no technical issues, you may find yourself unable to work on site, facing restrictions on the area that can be captured, or being denied permission to use the data.

First and foremost, it is important to confirm with the site administrator. In cemeteries, memorial parks, temple graveyards, communal burial grounds, and other places where gravestones are installed, each location has its own managing authority and operating rules. Prior approval may be required for matters such as work dates and times, access areas, bringing in equipment, moving nearby objects, and the handling of photographs and three-dimensional data. In particular, when working during hours when the general public is present, attention to traffic flow and sightlines is indispensable.

Next, aligning the client's understanding is also important. If the client has expectations such as "I thought the text would be clearly readable," "I thought all the surrounding parcels would be included," or "I thought it could be immediately turned into drawings," failing to share the scope and limitations of the deliverables in advance will lead to dissatisfaction after delivery. 3D scanning is not a panacea; what can be captured varies depending on the condition of the object and site conditions. Therefore, it's important to explain in advance what can be done and what will be difficult.

Also, because gravestones concern individuals and families, care must be taken with the scope of disclosure of recorded data. Three-dimensional data may include not only the shape of the gravestone but also inscription information and the surrounding layout. The rules for handling these materials will vary depending on whether they are limited to internal use, used in explanatory materials, or repurposed for research. To prevent issues with secondary use from arising later, it is necessary to clarify the intended purpose and the scope of sharing.

Regrets on site often stem less from a lack of technical skill than from insufficient coordination. Even if you make the effort to visit the location, if the permitted area is too limited so you cannot measure from the required positions, or if you cannot move surrounding objects and important surfaces remain hidden, you will not achieve the expected results. In 3D scanning of gravestones, observing on-site etiquette and management rules ultimately helps protect data quality. Advance coordination may seem like a detour, but it is actually the most efficient preparation.

Note 6 Decide the format of the deliverable data and how it will be used in advance

A surprisingly common failure in 3D scanning of gravestones is discovering after acquiring the data that “this format can’t be used,” “only a limited number of people can view it,” or “the deliverables I wanted aren’t included.” This happens because too much attention is focused on the measurement itself, and the design of the delivery format and how the data will be used is postponed.

There are various ways of thinking about three-dimensional data: formats treated as collections of points, formats treated as surfaces, formats suited to cross-sections and diagramming, and lightweight formats intended for viewing and sharing. In practice, the optimal format depends on who will use it and in what environment. Surveyors may want to verify detailed shapes, while managers may prioritize easy viewing. For maintenance planning, cross-sectional and dimensional checks are required, and public relations or presentations may call for clear visualizations.

If you proceed without deciding this, you'll end up with data that's too heavy to open or, conversely, data that's been oversimplified to the point of being unusable. In 3D scanning of gravestones, it's not necessarily helpful to hand over all the acquired data as-is. It's important that the data be organized in a form that's easy for users to handle and suited to its intended purpose.

Also, deliverables are not limited to three-dimensional models. Still images used to capture the current condition, diagrammatic materials that show key dimensions, outputs for checking each surface, and time-series organization for comparison — in practice, what is truly useful is often a combination of 3D data and supporting materials. Items that are managed continuously, such as gravestones, are more valuable when organized for easy later reference than when delivered as a one-off data set.

Furthermore, you should decide in advance where the data will be stored and how it will be viewed. Considerations such as where to save large datasets, whether on-site staff can open them immediately, and whether file formats will become obsolete during long-term storage are often deferred, but they are extremely important. It would be a shame to go through the trouble of 3D scanning only for no one to open the files months later, leaving only still images to be used.

To avoid regrets, you should confirm the type of deliverables, the viewing environment, any required processing, and how it will be operated before measurement. For 3D scanning of gravestones, success depends more on preparing the scans so they remain usable than on the act of acquisition itself.

Point 7: Don't stop at measurement—plan for storage and updates

3D scanning of gravestones is not something that ends once the data has been created. Rather, the important part is the operational side: how the data is stored afterward, and when and in what situations updates or re-comparisons are carried out. If you conduct it as a one-off without considering this, valuable data may go unused and you may have to repeat the same measurements.

Gravestones are long-lived objects, and over time they undergo weathering, leaning, soiling, loss or damage, repairs, and changes in their surrounding environment. Therefore, the value of 3D scanning lies not only in individual datasets but also in the ability to perform time-series comparisons. Enabling tracking of differences before and after repairs, changes in tilt, the progression of surface conditions, and the effects of surrounding maintenance increases their usefulness as management documentation.

For that purpose, storage rules are necessary. If you do not organize file-naming conventions, records of the date and location of photography, identification information for the target gravestone, the person in charge, the intended use, and so on, you will not know what the data represents when you review it later. Because three-dimensional data can look similar and differences between sites are hard to discern, organizing ancillary information is indispensable.

Also, the approach to updates is important. It is not necessary to re-measure every gravestone frequently, but those scheduled for repair, suspected of deterioration, or otherwise important to management are worth re-recording at certain milestones. When doing so, it is desirable to record them with the same scope and the same approach so they are easy to compare with the initial data. If this perspective is not present at the time of the initial measurement, it will be difficult to ensure consistency with subsequent data.

Furthermore, linking to the actual site location is also important for mid- to long-term operation. Being able to unambiguously identify on-site which gravestone is located where within the cemetery greatly affects management efficiency. Rather than using three-dimensional data alone, linking it with location information and registry records improves searchability and reusability.

What is worth noting here is the idea of streamlining on-site position verification. In practical work advancing 3D scanning of gravestones, it is essential not only to capture the target’s shape but also to reliably manage which gravestone was recorded at which location. In such situations, a system for quickly confirming positions on site and linking the recorded object to ledger information makes operations much more stable. Using an iPhone-mounted GNSS high-precision positioning device such as LRTK can make it easier to confirm target positions within a cemetery and organize recording points. 3D scanning itself is a technique for shape acquisition, but its management value increases when combined with positional information in the field. If you want to carry out gravestone record preservation and on-site verification in a more practical way, preparing position-management methods along with the 3D data will lead to operations you won’t regret.

Summary

To avoid regretting the 3D scanning of gravestones, it is important not to focus only on equipment and measurement methods but to design the overall process including purpose, accuracy, the condition of the subject, on-site conditions, coordination with stakeholders, delivery format, and long-term operation. In particular, because gravestones are installed outdoors for long periods, are highly individual, and require management considerations, the quality of pre-planning affects the outcome more than general three-dimensional measurement.

By clarifying the purpose of the recording, defining the necessary scope and accuracy, and developing a measurement plan suited to on-site conditions, you can more easily prevent rework and disappointing deliverables. Furthermore, by looking beyond delivery to storage, sharing, comparison, and updates, the value of 3D scanning increases substantially.

Moreover, to reliably operate 3D scanning of gravestones on site, it is essential not only to have shape data but also to manage how the target location is handled. If you want to streamline confirmation of the recorded object's location and the acquisition of on-site coordinates, combining high-precision positioning tools like LRTK can further improve the manageability of 3D scan data. For field personnel who want to avoid treating gravestone record preservation as a one-off task and instead carry it through to on-site verification with consistent accuracy, considering 3D scanning together with position management will be a major advantage for future field operations.