Architectural influence on narrative content in cultural heritage projection mapping

Abstract

Projection mapping has been widely adopted in the cultural heritage sector as a medium for immersive storytelling and public engagement. However, its content design is often treated as an open-ended creative process, lacking empirical understanding of how the intrinsic properties of heritage architecture may shape visual narratives. This study presents a structured investigation into the influence of architectural attributes, both physical (e.g., scale, surface flatness) and cultural-historical (e.g., designation level, functional legacy) on projection content logic. A dataset of 36 cases was analyzed through content classification, spatial structure mapping, and regression modeling to detect consistent patterns in content selection. The findings reveal that specific architectural conditions systematically affect the representation of historical, mythical, and performative elements in projection design. By revealing the structural and symbolic constraints that shape PJM narratives, this research reframes PJM from a purely creative tool to a culturally grounded medium. It highlights the importance of aligning digital design practices with the spatial and historical logic of heritage sites, offering a more effective and respectful pathway for cultural communication through technology.

Introduction

Projection mapping (PJM), as a digital visualization technology that utilizes architectural surfaces as display media, has been widely applied in the exhibition, interpretation, and dissemination of cultural heritage, achieving significant economic and social impacts¹. Heritage sites, museums, and historical urban districts worldwide have actively adopted PJM to enhance their attractiveness, broaden public recognition, and stimulate rapid growth in cultural tourism. However, alongside this widespread enthusiasm, a critical issue has emerged: many PJM projects prioritize visual spectacle at the expense of meaningful cultural expression, often neglecting or misrepresenting the historical context, cultural significance, and spirit of place inherent to heritage sites^2,3. Unfortunately, some projects have even displayed significant cultural misalignments—such as projecting abstract patterns or historically inaccurate content onto structures of profound historical significance, like ancient city walls or palaces. Such practices not only undermine the cultural dignity and authenticity of heritage sites but also contradict the fundamental principles of respect and rigor that should characterize digital cultural interpretation.

Beyond purely visual outcomes, production-side documentation and public reports from internationally recognized PJM events have provided valuable insights into how creators consciously respond to architectural affordances. For instance, San Antonio, the Saga projected onto the facade of San Fernando Cathedral explicitly framed the city’s history through the geometry and sacred symbolism of the cathedral (https://www.expressnews.com). Similarly, Jeanne(s), Cathédrale de lumière in Rouen treated the Gothic cathedral’s verticality and rose windows as narrative anchors, demonstrating how architectural detail became a dramaturgical device (https://vimeo.com/70856471). In Paris, the Nuit aux Invalides light and sound show was reported to intentionally evoke Napoleonic grandeur by aligning projected sequences with the site’s monumental dome and axial plan (https://www.sortiraparis.com/nuit-aux-invalides-2022-paris). Travel reports on Rome’s Forum of Augustus projection highlight how the ruin’s material fragments were reactivated as narrative surfaces, embedding historical episodes directly into surviving architectural forms (https://johnhendersontravel.com/forum-of-augustus-rome-light-show).

Comparable tendencies are also documented in recent cases. The Facade Festival in Vancouver emphasized how projection artists tailored their designs to the Vancouver Art Gallery’s neoclassical facade, integrating columns and pediments into rhythmic narrative frames (https://www.vanartgallery.bc.ca/facade-festival). In the French Région des Lumières program, organizers described how projection concepts were developed in dialogue with local heritage buildings, aligning content themes with site-specific symbolic values (https://regiondeslumieres.auvergnerhonealpes.fr). Similarly, Reflections at the Guggenheim Museum Bilbao explicitly echoed the building’s metallic cladding and undulating curves, with feather motifs and light rhythms reinforcing architectural identity (https://www.guggenheim-bilbao.eus/en/exhibitions/reflections). Finally, documentation from the Battersea Power Station projection provides direct evidence of industrial features, such as chimneys and turbine halls being integrated into thematic sequences referencing the site’s coal-fired past and contemporary redevelopment (https://batterseapowerstation.co.uk/whats-on/event/light-festival).

In summary, such production-side accounts—including interviews, press releases, and institutional statements, consistently suggest that architectural context is not a neutral screen but a structuring force in PJM design. The coupling between facade attributes and projected narratives emerges not only as a matter of aesthetic fit but also as an intentional strategy of cultural translation, whereby material forms, symbolic hierarchies, and historical functions are mobilized to guide content creation.

To systematically address these theories, our research team previously conducted studies from two complementary perspectives: the designers and the visitors. In our first study, we developed an original analytical method named “timeline analysis” and conducted an in-depth investigation of 45 PJM case studies from heritage sites worldwide, introducing the concept of “information tendency”⁴. Interestingly, the findings revealed that designers frequently preferred visually impressive but culturally shallow content to avoid complexities associated with historical narratives and rigorous semantic logic. This tendency underscores systemic deficiencies within the content-generation process, highlighting a significant absence of cultural guidance mechanisms in design decisions.

In the second study, from a visitors’ perspective, we established an innovative evaluation framework centered on “visitors’ recall of cultural information,” empirically validated through field research conducted at “Tangcheng” heritage site in Xiangyang, China⁵. The results indicated that visitors demonstrated higher levels of comprehension and memory retention for projection content that was culturally coherent and historically structured. Conversely, abstract visual effects lacking explicit cultural relevance resulted in considerably weaker recall outcomes. These findings further emphasized that deficiencies in cultural expression within PJM are not merely design issues but compromise visitors’ genuine cultural experience and understanding.

The aforementioned studies have provided theoretical and methodological innovations from both the supply (designer) and reception (visitor) perspectives. However, the mediating mechanism, specifically how heritage architecture acts as an active mediator influencing content creation and visitor reception, remains largely unexplored^6,7,8.

During earlier phases of our research, scholars outside the field of digital cultural tourism have questioned our fundamental theoretical premise, arguing that design should inherently allow creative freedom and therefore should not exhibit systematic constraints or predictable patterns regarding PJM content at heritage sites^9,10,11,12. However, from the perspective of employing digital media technology to communicate heritage culture, we hold a fundamentally different view.

We argue that the design of PJM content at heritage sites is obviously influenced by the intrinsic attributes of the heritage structures themselves: whether architectural, historical, or symbolic^13,14.

Given PJM’s public accessibility and significant communicative power, the projected content critically shapes visitors’ understanding and perception of cultural authenticity. Unlike in purely commercial contexts, designers in heritage environments are inherently constrained by factors such as structural form, materials, spatial arrangements, historical functions, and symbolic meanings^{15,16,17,18,19,20}. To address these debates empirically, our study utilizes systematic data analysis to demonstrate the explicit and quantifiable relationships between heritage attributes and PJM content choices.

Furthermore, a review of existing literature reveals that current studies on PJM within the context of cultural heritage predominantly focus on technical enhancement, immersive visitor experiences, and interactive effects. Most research emphasizes improvements in projection accuracy, visual fidelity, and visitor engagement. For instance, studies highlight the benefits of interactive projection in boosting visitors’ sense of participation and satisfaction^21,22,23,24, while others underscore the positive emotional impacts associated with immersive digital experiences^25,26. Additionally, some scholars have examined the interaction between digital media and physical architecture, introducing concepts such as projection mapping’s capability to provide architectural surfaces with “transcending mediation,” thereby creating additional spaces for artistic interpretation^27,28,29,30. Although these studies have extensively explored technical applications and experiential outcomes, they rarely address the active role of the heritage architecture itself in shaping the cultural narrative presented by PJM. Specifically, there remains a significant theoretical and empirical gap regarding how architectural structure and historical attributes systematically guide or constrain PJM content selection.

Therefore, this study aims to clarify how the structural characteristics of heritage architecture influence the design of cultural content in PJM, and to establish a theoretical framework describing the coupling relationships among architectural structure, historical attributes, and PJM cultural content. Specifically, this study introduces the theoretical concept of heritage architecture as a “mediator” in cultural content production, hypothesizing that architectural form, historical function, and cultural semantics shape content selection and narrative approaches in PJM design^31,32,33. The findings of this study will provide a robust theoretical foundation for content design practices in digital heritage, thereby enhancing the precision, authenticity, and cultural depth of future PJM applications (Fig. 1).

Fig. 1: Relationship between the three phases of the study.

The three-phase research framework addresses (First) information tendency, (Second) information evaluation systems, and (Third) the relationship between information and architectural carriers. These theoretical components are arranged in a logical sequence, where each phase builds upon the preceding one to construct a coherent analytical process.

Methods

Defining the cultural content typology in architectural heritage PJMs

The first step of this study aims to update and define the types and tendencies of cultural information represented in PJM content at architectural heritage sites. This step serves as the foundational phase of the overall research framework, providing the essential empirical basis for subsequent analysis of the relationship between content types and architectural carriers, as well as the construction of a coupling model between physical heritage attributes and PJM narratives (Fig. 2). Clarifying what types of cultural content are presented, and understanding their distribution patterns and frequencies, is a prerequisite for the next step^4,5.

Fig. 2

Timeline analysis method legend.

To fulfill this aim, the study adopted and refined the previously developed Timeline Analysis Method, introducing improvements in both classification criteria and timeline construction procedures to enhance analytical stability and reproducibility. The timeline analysis method was designed to deconstruct PJM content and identify overall tendencies in the types of cultural information presented. By arranging different content segments in chronological order, this method provides a clear and structured way to interpret PJM narratives over time^34,35,36.

In terms of classification, this study adhered to the four-category system validated in earlier research: Macro-level narratives (history-related like war history, historical daily life scenes, historical backgrounds and origins, historical figures), architecture-related like structure and construction processes, historical appearances), Micro-level cultural content (folklore-related like mythical stories, folklore operas and artifact-related like cultural relics, paintings and patterns, traditional costumes), performative/artistic expression, and environmental/contextual content (Fig. 3).

Fig. 3

Color classification system for information.

Regarding the definition of “Macro/Micro” information, the primary duty of “Macro” is “the perspective of describing history”^37,38,39,40. The “Macro” information is determined based on “the span of historical timeline”, e.g., by displaying information on the structure and restoration process of a heritage building, the audience will be able to visualize and understand the historical events and the context of the period. When designers intend to describe “the origins,” “the construction and building process,” and “the status of the site in history” to visitors, it is necessary to introduce the historical context and cultural values of the heritage site in a historical flow perspective, with reference to a time span of decades to centuries (Fig. 4). Essentially, “Macro” information contained in a cultural heritage site but indirectly observable or experienceable. Visitors understand of the “Macro” require communication through various mediums (text, narration, panel, etc.).

Fig. 4

Definition of “Macro” and “Micro” information.

The “Micro” referred to the information as “Religion, the primary duty of “Micro” is “demonstrating the distinctive culture and aesthetic characteristics of the precise period”. The “Ornament and art” information is determined based on “representative historical points of time.” For instance, by displaying information on historical garments or artifacts from a specific era, the audience will understand the craftsmanship and textile technology that emerged at that historic point in time (Fig. 4). Compared with “Macro,” the essence of “Micro” is more inclined to “reflect the Historical flow history from small cultural elements”. When designers intend to be reflecting historical development through individual stories, it is necessary to introduce the cultural characteristics and conservation values from an ornament and art-historical perspective, referring to the stories of historical figures, costumes, motifs, etc. Furthermore, the definitional standards for each category of cultural information are explicitly articulated in this study^41,42,43,44.

• Historical backgrounds and origins: Content depicting the founding of a nation or civilization, often featuring iconic events such as royal rituals or flag-raising ceremonies.

• Historical daily life scenes: Scenes illustrating everyday life in historical settings, often derived from paintings or cultural records.

• War history: Content centered on historical warfare, typically including soldiers, weapons, and battlefield imagery.

• Historical figures: Visual representations or narrative references to significant historical individuals, including portraits and biographical episodes.

• Structure and construction processes: Information about the building’s construction techniques and architectural components, such as beams, roofs, and pillars.

• Building historical appearances: Reconstructions of a building’s physical changes over time, reflecting structural evolution and material transformations.

• Paintings and patterns: Traditional aesthetic expressions, including decorative motifs, totems, and artistic patterns.

• Traditional costumes: Cultural representations of clothing styles, often used to infer character identity, era, or function.

• Cultural relics: Visual emphasis on tangible heritage objects, typically shown in association with historical figures or scenes.

• Mythical stories: Depictions of myths, supernatural beings, or symbolic non-realistic imagery rooted in folklore.

• Folklore, Poetry, or Opera: Content focused on traditional music, dance, and theatrical performance, often linked with costume, pattern, or historical context.

This framework supports clear cultural stratification and facilitates reliable cross-case comparisons. Furthermore, the color-coding scheme for each content type has been standardized to improve visual clarity and ensure consistent representation of information across all case diagrams (Fig. 5).

Fig. 5: Procedure for creating timeline analysis charts.

The five-step procedure covers the entire process from defining the duration of each case (Step 1), through identifying the basic categories of information (Steps 2–3), to completing the final proportional statistics (Steps 4–5). The color classification of information strictly follows the standard introduced in Fig. 3, ensuring consistency and comparability across all cases.

This updated version represents the finalized form of the timeline analysis method, serving as its most complete and stable iteration for future research applications.

With regard to the analytical workflow, this study enhanced the timeline construction process by refining each stage: it conducted a full viewing of the PJM video, segmented the narrative units, identified the dominant cultural content per segment, applied standardized color codes and duration tracking, and finally generated structured timeline diagrams. These timelines represented the temporal distribution of cultural content types across the projection sequence. A total of 36 representative PJM cases were analyzed using this method, which resulted in a unified, structured annotation dataset that underpinned the subsequent stages of architectural type matching and multivariate coupling analysis.

Analyzing the relationship between architectural carrier types and PJM cultural content

The second step of this study aimed to examine whether there was a structural relationship between the type of architectural carrier and the cultural content presented in PJM, that is, whether the spatial form of the projection surface influenced the type of cultural narrative displayed. Within the overall research framework, this step served as an intermediary stage that identified potential correspondences between architectural features and content expression, laying the groundwork for the multivariate coupling analysis in the next phase.

Operationally, this step classified the architectural carriers of the 36 PJM cases from the previous phase into three groups based on structural and visual traits: Single large-scale construction (9 cases), City and historic walls (9 cases), Shrines/temples (9 cases) and composite constructions (9 cases). Each category displayed unique spatial features, visual prominence, and projection suitability that shaped PJM content choices. Using the Step 1 annotated dataset, the study measured the frequency and duration of each cultural content type across these categories to identify trends, e.g., flat facades often used for macro-historical narratives, while curved surfaces more for performative or atmospheric content.

Modeling the relationship between architectural attributes and PJM content

The third step examined whether intrinsic architectural attributes significantly influence the type of cultural content presented in PJM. Building on the structured dataset from previous phases, architectural attributes were defined as independent variables, including^45,46,47:

• Structural form (flat, curved, vertical, composite);

• Historical function (e.g., military defense, religious ritual, royal administration, urban infrastructure);

• Cultural semantic significance, quantified from official heritage documents and nomination texts.

The dependent variables were the frequency and duration of each cultural content type identified in the timeline analysis. For ordinal responses (e.g., content occurrence levels Q9–Q20), Ordinal Logistic Regression models (proportional odds) were applied, using encoded scores of Q1–Q8 architectural attributes as predictors. Model parameters included estimated coefficients (log-odds), standard errors, p-values (Wald test), and McFadden’s pseudo-R², enabling evaluation of both effect size and model fit.

Significance testing identified which architectural attributes had statistically meaningful associations with specific PJM content categories. Positive coefficients indicated that higher attribute scores increased the likelihood of a content type appearing less frequently, while negative coefficients implied association with higher content frequency^48,49,50. This approach provided a statistically verifiable basis for the hypothesized coupling relationship between architectural structure and cultural expression, supporting the proposition that architectural carriers act as active mediators in PJM design.

Results

Case selection and information tendency overview

To systematically analyze the structure and characteristics of cultural content in PJM projects at architectural heritage sites, this study compiled and reviewed relevant cases from the period spanning 2013 to 2025. From our existing database of international PJM cases, we selected 36 representative projects based on clearly defined inclusion criteria:

• The cultural content presented in the PJM projects had a moderate to high degree of relevance to the historical and cultural significance of the heritage sites, explicitly conveying cultural values rather than focusing solely on visual effects;

• Each selected case provided comprehensive video documentation or detailed visual and textual materials, sufficient for rigorously conducting the timeline analysis method;

• The projection surfaces were identified as integral parts of architectural heritage structures (e.g., facades, roofs, towers, bridges), explicitly excluding stand-alone installations or stage-oriented projection projects.

These carefully selected 36 cases encompassed diverse architectural forms, cultural regions, and projection styles, thus providing a robust foundation for subsequent variable construction and comparative analysis. A detailed list of these selected cases is summarized in Table 1 (Video links of 36 cases: https://www.youtube.com/channel/UCtlOwB037KZpxkVstj0FFUQ/playlists; https://www.teamlab.art/zh-hans/; https://www.tamschick.com/projekte/atturaif-the-living-museum/; https://momentfactory.com/work/all/all/aura; https://www.maxin10sity.net/portfolionew; https://naked.co.jp/en/works). Utilizing the timeline analysis method, this study further classified the 36 PJM cases into three primary structural categories and two specialized sub-categories based on their most significant architectural features and spatial configurations:

Table 1 36 cases differentiated by structure

Primary categories (36 cases) (Table 1):

• Single large-scale construction (9 cases): Projects mainly involving projections onto large horizontal facades characterized by complex architectural elements, structural detailing, or intricate surface textures.

• City walls and other historic walls (9 cases): Projects featuring projection mapping primarily onto extensive, historically significant city walls, gates, or defensive structures, emphasizing their scale, linearity, and historical context.

• Shrine, temple (9 cases): Projects specifically using traditional large-scale Asian roof structures, such as East Asian temples, pagodas, or palaces, leveraging their distinctively curved roofs, decorative eaves, and symbolic architectural details.

• Composite construction (9 cases): Projects using both the horizontal and vertical carrier structures of the building, typically requiring unique content alignment due to their vertical format and symbolic prominence.

This structural categorization provides a structured basis for the subsequent analysis of relationships between architectural attributes and PJM content tendencies. In the subsequent analysis, each architectural category described above will be examined individually, with a particular emphasis on summarizing the overall information tendencies observed through the timeline analysis method. Rather than detailed case-by-case analyses, this stage aims to broadly characterize how each specific structural category tends to influence and shape the cultural narratives presented in PJM practices. Three representative examples from each primary and specialized category will be briefly highlighted to illustrate typical content patterns and reinforce the general conclusions regarding the impact of architectural features on PJM content selection and expression.

The first category is “Single large-scale construction.” Representative cases include the 2015 Osaka Castle 3D Mapping Super Illuminations, 2018 Discover Bulgaria (Municipality in the Italian capital), and the 2018 Bicentenary Projection at the Prado Museum. Based on color distribution and information layering observed in these cases, this category of PJM exhibits a clear preference for macro-level content, particularly historical backgrounds, narratives of war, and architectural construction details (Fig. 6) (Other 6 cases can refer to the Supplementary Figs. 1 and 2).

Fig. 6: Typical examples of single large-scale construction.

Representative projection mapping cases (a) Discover Bulgaria, (b) Prado Museum, c Osaka Castle. The color classification of information strictly follows the standard introduced in Fig. 3.

These projections typically demonstrate high visual complexity, characterized by a rich variety of overlaid content types, often exceeding six distinct categories per case. Moreover, macro- and micro-level information is frequently interwoven within the same sequence, allowing audiences to absorb a dense array of cultural references within a short viewing span. However, one notable drawback of this category lies in its tendency toward information fragmentation. Many of the cases fail to establish a coherent narrative structure; for instance, mythological scenes are often inserted abruptly during sequences depicting historical events. While such combinations may enhance visual impact, they risk confusing audiences or distorting the intended cultural message.

This fragmented content structure may be attributed to the spatial characteristics of buildings in this category. Their expansive facades and complex roofs provide designers with greater creative freedom. However, without a unifying interpretive framework, this flexibility can increase the risk of incoherent narratives.

The second category is “City walls and other historic walls.” Representative cases include the 2021 Tangcheng Building Surface Projection Mapping, 2018 Nagoya Castle: Night Castle Owari Edo Fantasia, and the 2022 Pingyao Ancient City Projection Mapping. Based on the distribution of visual elements and color layers, this category shows a strong preference for micro-level content, particularly the display of traditional costumes, cultural relics, particularly the display of traditional costumes, cultural relics, and most frequently, folk dance and staged performances costumes, cultural relics, and most frequently, folk dance and staged performances (Fig. 7). (Other 6 cases can refer to the Supplementary Figs. 3 and 4.)

Fig. 7: Typical examples of City walls and other historic walls.

Representative projection mapping cases (a) TANGCHENG, (b) Nagoya castle, (c) Pingyao ancient city. The color classification of information strictly follows the standard introduced in Fig. 3.

Unlike other categories, PJM projects in this group exhibit a notable tendency toward segmented content structure, in which micro- and macro-level information are rarely integrated within a single sequence. Instead, they are often presented in separated time intervals (Fig. 7). Although some cases feature brief combinations—such as traditional attire or patterns appearing within historical daily life scenes—these are fundamentally rooted in the reproduction of traditional painting esthetics, where “historical daily life scenes” serves more as a thematic subtext than a standalone narrative.

A distinctive feature of this category is its consistent use of theatrical performance as a medium to convey micro-level information, with traditional clothing and artifact styles serving as focal points. This tendency is closely tied to the spatial characteristics of the architectural carriers themselves. City walls and gates often provide large, uninterrupted horizontal surfaces, which naturally lend themselves to stage-like projection formats. In essence, these PJM presentations function similarly to heritage-based stage design, where the architectural backdrop becomes an active part of a choreographed visual performance. The formal properties of these structures directly shape the way cultural information is organized and communicated in PJM content.

The third category is “Shrine, temple.” Representative cases include the 2025 Saiku Cultural Art Night, the 2020 Japan Expo at the Kashima Shrine Gate, and the 2024 Projection Mapping on the Mieido Hall of Senjuji Temple (a National Treasure). Based on the visual distribution of color-coded content in the timeline analysis, PJM projects in this category also exhibit a clear preference for micro-level information, particularly traditional patterns, decorative motifs, and clothing-related content. (Other 6 cases can refer to the Supplementary Figs. 5 and 6).

Unlike the “City walls and other historic walls” category, these cases frequently integrate macro-level content, especially the subtypes “Structure and construction processes” and “Building historical appearances”. In many instances, macro and micro content are presented without clear separation, forming hybrid sequences that blur informational boundaries (Fig. 8). A considerable number of examples in this category also include short descriptions or visuals of historical daily life scenes, particularly when illustrating architectural functions or ritual practices, thereby enhancing the cultural authenticity of the projection narrative.

Fig. 8: Typical examples of shrine, temple.

Representative projection mapping cases (a) Saiku, (b) Kashima shrine, (c) Senjuji. The color classification of information strictly follows the standard introduced in Fig. 3.

Notably, the narrative logic in this category tends to follow a small-stage performance format, rather than adhering to a chronological storyline or time-sequenced historical narration. This content delivery style is closely related to the structural properties of large, complex Asian roofs, which feature inclined surfaces, interlaced eaves, and decorative ridgelines. From a technical perspective, the complex geometry of these roofs increases the risk of calibration errors. Therefore, designers avoid long-form narrative content and instead favor mythical themes and decorative visuals that are less demanding.

The final category is “Composite construction” (Fig. 9). Representative cases include the 2018 Aachen Cathedral 40th anniversary of being awarded UNESCO World Heritage Site, 2020 San Fernando Cathedral-The Saga San Antonio, 2022 Hôtel des Invalides-La Nuit aux Invalides. (Other 6 cases can refer to the Supplementary Figs. 7 and 8.)

Fig. 9: Typical examples of composite construction.

Representative projection mapping cases (a) Aachen Cathedral, (b) San Fernando Cathedral, (c) Hôtel des Invalides. The color classification of information strictly follows the standard introduced in Fig. 3.

Compared with other groups, PJM productions in this category are generally of longer duration, with content sequences following a more linear narrative structure. Owing to their large building volumes and the absence of steep, segmented rooflines typical of East Asian architecture, these facades offer

designers broad, uninterrupted projection surfaces. This spatial advantage often translates into a strong emphasis on architectural history, both the structural evolution of the building and reconstructions of its historical appearance, forming the visual and narrative core of many works in this group. In most cases, the presentation of these architectural features is closely interwoven with the site’s historical or religious background, leading to a high frequency of content related to historical background and origin as well as war history. The result is a narrative mode that highlights the building’s chronological transformations and its role within broader historical events.

Based on a timeline content analysis approach, this study conducted a comparative evaluation of cultural information distribution across 36 representative PJM cases, categorizing them into four architectural carrier types: (1) horizontal surfaces with complex structures, (2) city or historic walls, (3) shrines/temples, and (4) composite constructions. To avoid bias in the statistical results, the overrepresented category “paintings and patterns” was excluded. To enhance interpretability, the analysis employed the average duration (in seconds) of each information category’s appearance as the statistical basis (Table 2).

Table 2 Information tendency of 36 cases (average duration in seconds)

The findings reveal systematic and statistically significant differences in content selection across architectural types. Composite constructions: primarily European castles and cathedrals, show a strong preference for macro-level narratives, especially historical backgrounds and war histories, with micro-level elements (e.g., mythical stories, cultural relics) used mainly to reinforce historical storytelling. Their regular facades facilitate projection alignment, enabling designers to leverage architectural geometry as a narrative framework and deliver precise, story-driven content.

In contrast, shrines and temples: mostly small-scale Asian heritage structures—exhibit a markedly different design logic. Limited projection surfaces and the sacred cultural context of these buildings tend to orient designers toward artistic-cultural displays rather than extended macro-historical storytelling. Content typically blends scenes of daily life, symbolic motifs, and traditional attire, resulting in modular, esthetically driven segments rather than strictly chronological narratives.

This contrast underscores the decisive role of architectural historical attributes and morphological features in shaping PJM content strategies. This logic further explains why “city or historic walls,” which are naturally suited to stage-like presentations, tend to feature large amounts of traditional dance and costume-related information, whereas “horizontal surfaces with complex structures” present a more balanced distribution of information types due to the diversity of carrier forms. Consequently, this stage of analysis supports the study’s core hypothesis: the historical characteristics and spatial structures of heritage architecture actively guide designers’ judgments in PJM content selection, sequencing, and integration.

Relationship between specific carrier and PJM content

Before discussing the relationship between specific architectural carriers and PJM content, this study must first address a foundational question often raised in early project planning: Is it necessary to apply projection mapping to cultural heritage architecture at all? Some experts have questioned whether such efforts differ meaningfully from projections on neutral surfaces like screens or temporary installations. In response to this concern, the present study begins by clarifying the distinctive value and functional advantages of PJM when applied to heritage sites, establishing the rationale for treating heritage structures not as passive surfaces, but as integral components of cultural expression^51,52.

PJM enables content output in more complex environments and vehicle surfaces (Fig. 10). Compared with ordinary animation and film output content on a smooth and stabilized 2D surface with explicit size limitations, the implementation of PJM demands the more precisely examination of vehicle shapes and materials. For instance, PJM on building surfaces solves the issue of reflections from metal/glass materials by applying holographic foils or eliminates the glare interference to the interior by providing an illuminant mask.

Fig. 10

Difference in projection methods.

Given PJM’s adaptability to complex surfaces, its content design often aligns with the structure of the projection carrier (building, bridge, wall, etc.), influencing the storytelling of historical events. Unlike flat-screen projection, building-surface PJM can integrate facade contours to depict the appearance and transformations of heritage architecture over time⁵³, helping visitors perceive reconstruction areas and scale within a realistic setting.

A representative example is the 2018 PJM show at Aachen Cathedral, marking its 40th anniversary as a UNESCO World Heritage Site (Fig. 11). The 20-min program matched the cathedral’s structure, narrating its construction sequence, damage from a historic fire, and restoration outcomes. Each change in appearance was linked to a corresponding historical event, using chronological lighting of different built sections to achieve effects beyond conventional animation. This case illustrates PJM’s advantage in combining structural integration with thematic storytelling.

Fig. 11

Displaying the history of architectural development.

While PJM accommodates more complex carriers than standard animation, it typically condenses a site’s cultural narrative into brief programs rather than providing exhaustive historical accounts.

Earlier in this study, PJM cases were classified by the structural characteristics of heritage buildings to identify content tendencies. However, prior analysis aggregated content at the case level, without isolating the contribution of specific architectural elements.

To address this, we developed a schematic vector diagram mapping the most frequently activated projection zones, using color codes for primary (blue), secondary (aqua), and non-projection (gray) areas. By examining the primary and secondary projection areas across cases, this study identifies four frequently occurring architectural carrier types for in-depth analysis: Horizontal surface with complicated structure, Smooth continuous walls, Large Asian building roofs, and Vertical planes like towers. These carrier types either co-exist within a single PJM case, often with a clear hierarchy in content emphasis, or serve as the sole structural basis for an entire projection event (Fig. 12)^54,55,56,57.

• Horizontal surface with complicated structure refers to large-scale facades composed of intricate geometries, such as cornices, segmented planes, or ornamented bases, which allow for layered and visually segmented content distribution.

• Smooth continuous walls are characterized by uninterrupted, linear surfaces such as fortification walls or outer curtain walls, which often serve as panoramic storytelling platforms and support horizontal narrative flows.

• Large Asian building roofs typically feature sloped planes, multi-tiered eaves, and intersecting ridges, presenting projection challenges but also unique opportunities for symbolic and modular content composition.

• Vertical planes like towers include slender or centralized vertical structures (e.g., bell towers, minarets, or clock towers), which are often utilized to represent temporal or hierarchical historical sequences through vertical stacking of visual information.

Fig. 12

Main carrier types for PJM in cultural heritage sites.

In the following section, PJM cases are categorized by the presence and combination of carrier types, cross-referenced with timeline analysis results to assess how carriers influence content tendencies and functional roles. This approach clarifies each structural element’s contribution to the narrative and visual logic of projection mapping in heritage contexts. By linking architectural structure types with projection carriers, several patterns emerge (Table 3):

• Heritage sites typically employ two carrier types, often pairing horizontally complex surfaces with large Asian roofs or with vertical planes like towers.

• Horizontally complex surfaces are the most common carrier, serving as the primary projection zone in most cases and supported by secondary carriers for content richness and spatial depth.

• Although large Asian roofs pose technical challenges due to their geometry, designers increasingly use them effectively. In many cases, roofs not only complement flat surfaces but also serve as key narrative zones in PJM composition.

Table 3 Carrier types possessed in various structures of the building

In order to further refine the relationship between different architectural carriers and PJM content distribution, this study adopted a new quantitative analysis approach. Specifically, for each category of cultural information, we calculated the proportion of its occurrence on a specific carrier relative to its total occurrence across all cases, using the formula: (duration of information on the carrier)/(total duration of information across all cases) × 100%. This percentage reflects the relative concentration of specific cultural information on different carrier types, providing a basis for examining how architectural structures influence content organization within PJM narratives (Table 4). Based on this approach, we generated a visualized mapping of information tendencies and conducted detailed analyses for four major carrier types as follows (Fig. 13).

Fig. 13: PJM features of displaying information on various surfaces.

The statistical basis for this section is derived from the timeline analysis method and the authors’ manual coding.

Table 4 Expert information to assist in case judgment

Across the examined cases, clear tendencies emerged in the way different architectural carriers influenced the thematic organization of PJM content, with implications that extend beyond descriptive categorization. Horizontally complex surfaces, such as palace facades or cathedral exteriors, most frequently served as primary projection zones, naturally supporting multi-threaded historical narratives that capitalized on their spatial depth and morphological diversity. Smooth, continuous walls, by contrast, encouraged modular and self-contained cultural units: performances, costume depictions, and other easily legible segments, that enhanced thematic clarity but often resisted integration into broader narrative arcs. Large East Asian roofs presented a hybrid logic, fusing macro-historical context with micro-symbolic detail, using modular narrative units to reconcile structural complexity with symbolic density. Vertical carriers, such as towers or spires, constrained by their narrow projection fields, consistently prioritized linear, structure-centered narratives that reinforced temporal depth and commemorative significance over expansive cultural storytelling.

Viewed through a design-thinking lens, these patterns suggest that PJM narrative composition should not be conceived as a purely content-driven process but as a negotiation with the morphological and symbolic affordances of the projection carrier itself. Expansive, articulated surfaces invite layered, historically anchored storytelling that benefits from thematic branching and symbolic interplay, while smooth planar walls reward strategies prioritizing clarity, segmentation, and rhythm. Roofs offer the possibility of synthesizing macro and micro scales into a single coherent visual framework, but require careful spatial choreography to avoid visual overload. Vertical forms, though less accommodating to diverse content, can be leveraged as mnemonic and commemorative anchors when their spatial constraints are recognized as design assets rather than limitations. In this sense, the typology of the architectural carrier becomes an active co-author of the narrative, shaping not only what cultural information can be shown but how it can be understood, thereby reinforcing the role of heritage architecture as a generative framework for content strategy in projection mapping design.

Design of “Case personification” analysis

Following the analysis of how physical structural characteristics influence PJM content selection, this study extends the inquiry to examine how architectural history and functional attributes condition projection strategies. Beyond the aggregated tendencies observed across carriers, an individualized perspective was introduced through case personification analysis, allowing for a more nuanced understanding of how specific buildings inform cultural expression. While spatial form directly constrains the projection surface and determines the technical feasibility of content placement, deeper historical, functional, and symbolic attributes systematically shape narrative choices. Such non-physical attributes: including original functions, cultural status, historical evolution, and associated myths, create interpretive frameworks that guide the prioritization of certain types of cultural information in PJM presentations.

This study innovatively proposes a “case-personification” analytical method. This methodology treats each architectural heritage site and its corresponding PJM event as an individual “research subject,” systematically recording their physical attributes, historical-cultural characteristics, and PJM content distribution through a structured questionnaire. Such an approach enables consistent and organized data collection, facilitating subsequent statistical analysis and modeling (Table 5).

Table 5 “Case-personification” analytical method

To assist the authors in more accurately identifying and verifying the information associated with each case, five experts were invited to participate in the content verification process (Table 4). An expert panel of five professionals was convened to evaluate projection mapping content in 36 heritage architecture case studies. The panel was deliberately interdisciplinary, including members from academia, cultural heritage management, and digital media practice. Each expert was selected for a complementary area of expertise—for instance, cultural heritage studies, architectural history, digital humanities, and visual storytelling, ensuring broad domain coverage All panel members have advanced qualifications (e.g., professor, curator, or researcher) and extensive experience in their respective fields. This diverse composition aligns with best practices for comprehensive, multi-faceted analysis, lending rigor and balance to the evaluation process.

Specifically, this research designed a comprehensive questionnaire comprising three main dimensions: architectural physical attributes, historical-cultural attributes, and the distribution of cultural information in PJM content. The physical attributes include building scale, exterior material style, surface flatness, and spatial arrangement; historical-cultural attributes encompass heritage classification, historical era, original functions, and preservation state of historical facades and materials. The PJM content dimension quantitatively records the relative proportions of various cultural information types identified from the timeline analysis results. This structured data framework effectively converts traditionally qualitative and abstract historical-cultural attributes into quantifiable variables, providing robust empirical support for statistical modeling.

Upon completion of data collection for all 36 cases, each architectural heritage site was defined as a distinct analytical entity, characterized by specific physical attributes, cultural-historical features, and PJM content composition. These standardized case profiles were then compiled into a structured dataset suitable for statistical evaluation. To enable controlled examination of the relationships between these variables, a synthetic dataset of 36 cases (corresponding to 36 projection mapping events) was generated, preserving the rank-correlation structure of the original Spearman matrix. In this dataset, variables Q1–Q4 represent the physical attributes of the building (e.g., scale, exterior style), Q5–Q8 denote the site’s cultural and historical attributes (e.g., heritage designation level, construction era), and Q9–Q20 are ordinal outcome variables quantifying the presence of specific cultural content types within the PJM presentations. Q9–Q19 were measured on a five-point ordinal scale (1 = “Plenty (≥45% content)” to 5 = “None”), while Q20 records the proportion of non-informational filler content, also coded on a five-point scale from “Plenty” to “None.” This integrated dataset provides the empirical basis for applying ordinal logistic regression and correlation analyses to examine the relationships between architectural attributes and PJM content tendencies, and to identify the distinct effects of physical and cultural-historical features on design choices.

In the forthcoming data analysis section, this study aims to address the following core questions:

• To what extent do the basic architectural attributes (Questions 1–8) influence the types of PJM cultural content presented (Questions 9–20)?

• Between architectural physical attributes (Questions 1–4) and cultural-historical attributes (Questions 5–8), which exerts a more significant impact on PJM content design, or do they affect different content types in distinct ways?

• What is the relationship between the physical characteristics of architecture (Questions 1–4) and the proportion of non-informational PJM content (Question 10)?

• Correlations between various information internally, e.g., which information tends to appear bound, which information is presented in conflict with each other, etc.

Relationship between architectural history and functional attributes and PJM content

Reliability and validity tests were conducted on the coded data of 12 information content categories from 36 architectural projection mapping cases to ensure measurement reliability and structural validity. Cronbach’s α was used to assess internal consistency, yielding an overall α of 0.874, above the 0.80 benchmark, indicating high reliability. Dimension-specific α values ranged from 0.812 to 0.889, confirming strong internal consistency across categories.

For validity, the Kaiser–Meyer–Olkin (KMO) measure of sampling adequacy and Bartlett’s test of sphericity were applied. The KMO value was 0.846, surpassing the preferred threshold of 0.80, suggesting that the data were suitable for factor analysis. The result of Bartlett’s test was statistically significant (χ² = 512.37, df = 66, p < 0.001), further confirming that the correlations among variables were sufficient to support subsequent modeling analyses (Table 6). These results indicate that the “case-personification”-based content coding system adopted in this study demonstrates strong internal consistency and structural validity, providing a reliable measurement foundation for the following descriptive statistics and regression analyses.

Table 6 Reliability and validity test results

Since the earlier stage of this study has already employed the timeline analysis method to comprehensively deconstruct the information tendencies of PJM cases and to conduct detailed quantitative statistics for each information type, the descriptive analysis and the contents of the Spearman correlation matrix will not be reiterated here. Readers may refer to the Supplementary information for these details. (Descriptive statistics and Spearman correlation matrix refer to the Supplementary Tables 1 and 2).

The following section presents the significance analysis of correlations. In this study, a Spearman rank-correlation analysis was conducted between 11 cultural content indicators and 8 architectural attribute variables (Q1–Q8) across 36 architectural projection mapping cases, aiming to examine the statistical associations between different architectural characteristics and the presentation of projection content. The results indicate that multiple variable pairs exhibited correlation coefficients reaching statistical significance (p < 0.05), with the top ten absolute correlation coefficients ranging from 0.412 to 0.593 (Table 7).

Table 7 Top 10 pairs of variables with significant correlation

We will interpret the correlation results and provide a brief analysis of their underlying causes:

• Architectural structural complexity × “Structure and construction”: Q2 showed the strongest correlation (ρ = 0.593, p = 0.001), indicating that more complex structures tend to highlight construction details, structural features, and craftsmanship in PJM narratives. Complex forms provide more surfaces for layered visual storytelling.

• Historical importance × “Historical background and origin”: Q4 was strongly and positively correlated (ρ = 0.561), suggesting that historically significant buildings often present their origins and development, enriching cultural depth and fostering educational value.

• Religious/ceremonial function × “Mythical stories”: Q6 correlated positively (ρ = 0.548), showing that such buildings frequently integrate symbolic myths to reinforce spiritual atmosphere, though care is needed to balance symbolism with historical accuracy.

• Structural complexity × “Paintings and patterns” Q2 showed a positive link (ρ = 0.523), indicating that intricate structures accommodate complex decorative patterns without overcrowding, enhancing depth.

• Building scale × “War history”: Q3 had a moderate positive correlation (ρ = 0.506), reflecting that larger-scale heritage sites, such as castles and fortresses, often emphasize warfare and defense narratives, aligned with their historic military roles.

• Regional folk activity level × “Folklore, poetry or operas”: Q7 correlated positively (ρ = 0.494), suggesting that sites in active folk regions incorporate more local stories and performance elements.

• Building type × “Traditional costumes”: Q1 was positively correlated (ρ = 0.478), indicating certain building types (e.g., palaces, opera houses) are well-suited for costume culture displays, though without coherent scene logic, such content risks becoming mere visual ornamentation.

• Conservation status × “Historical figures”: Q5 correlated positively (ρ = 0.466), suggesting that well-preserved sites are more conducive to depicting historical characters with vividness and accuracy.

• Historical importance × “Cultural relics”: Q4 showed a positive link (ρ = 0.445), confirming that historically important sites are often used to showcase cultural relics.

• Religious function × “Historical daily life scene”: Q6 had a moderate positive correlation (ρ = 0.412), possibly reflecting the historical role of religious buildings as both community and living spaces.

To provide a more intuitive depiction of the interrelationships among variables, a Spearman correlation coefficient heatmap was generated to facilitate a data-driven and well-founded synthesis at this stage.

As shown in Table 7 and Fig. 14, multiple cultural content categories exhibit strong and statistically significant correlations:

• Dual driving roles of architectural attributes and design strategies: The heatmap and correlation analysis show that the physical attributes of architecture (Questions 1–4) and its cultural–historical attributes (Questions 5–8) exert differentiated yet complementary influences on PJM content design. Physical attributes primarily affect media adaptability and visual performance potential, as seen in strong correlations between structural complexity and both “Structure and construction” (ρ = 0.593) and “Paintings and patterns” (ρ = 0.523). This suggests complex structures are often used for layered narratives and ornamental presentation, leveraging their three-dimensional surfaces and intricate details. These tendencies reflect both technical affordances and designers’ recognition of narrative opportunities in complex geometries. Cultural–historical attributes more strongly shape narrative themes and cultural depth: historical significance correlates with “Historical background and origin” (ρ = 0.561), and religious function with “Mythical stories” (ρ = 0.548), showing that designers actively translate cultural context into narrative anchors. Physical and cultural attributes thus interact to balance technical feasibility with storytelling value.

• Patterns of co-occurrence and exclusivity in narrative construction: High correlations between certain content categories reveal thematic clustering in PJM narratives. For example, “Paintings and patterns” and “Historical background and origin” have the highest positive correlation (r = 0.72), while “Mythical stories” is linked with “Traditional costumes” (r = 0.57) and “Historical appearance” (r = 0.55). These combinations are intentionally bundled to provide both visual richness and cultural depth, enhancing immersion and aiding cultural memory. By contrast, “Historical daily life scenes” shows lower correlations with other categories, likely due to dependence on specific socio-cultural contexts or building functions, limiting reuse across scenarios. From a design strategy perspective, heritage sites with substantial historical weight may benefit from multi-dimensional narrative clustering, whereas sites with singular functions or highly specific contexts may be better suited to deep exploration of a single theme.

Fig. 14

Heatmap of correlations between PJM cultural content categories.

The correlation analysis indicated significant associations between multiple architectural attributes and PJM cultural content; however, these results could not simultaneously capture the interactions among variables or quantify the independent effect of each attribute. Accordingly, while preserving the original rank-correlation structure, a Gaussian copula method was employed to generate simulated data, followed by the application of ordinal logistic regression for multivariate analysis. This approach aimed to further verify whether the identified structure–content relationships remained significant after controlling for other factors, and to evaluate the direction and magnitude of each building feature’s influence on the presentation of different content types.

In the regression modeling, Q9–Q20 were treated as ordinal dependent variables, and Q1–Q8 served as independent variables, with separate proportional odds models established for each. This method evaluated how the physical and cultural attributes of architecture affect the likelihood of different PJM content types appearing. All predictors were coded as ordinal/numeric variables under the proportional odds assumption, with model outputs including estimated coefficients (log-odds), standard errors, and p-values (Wald tests). McFadden’s pseudo R² was calculated to assess model fit, and likelihood-ratio chi-square (LR χ²) tests were performed to evaluate the overall statistical significance of each model.

Tables 8–10 present the regression results for each content type outcome (Q9–Q20), organized by thematic group. Each table lists the predictor variables (Q1–Q8) along with their estimated coefficients, standard errors (SE), and p-values. Threshold (cut-point) estimates for the ordinal logit models are omitted for brevity, as the focus is placed on the relationships between predictors and outcomes. Significance levels are indicated in the tables using asterisks (*p < 0.05, **p < 0.01, ***p < 0.001). Pseudo R² and model fit statistics are reported beneath each table.

Table 8 Ordinal logit results for historical content (Q9–Q12)

Table 9 Ordinal logit results for architecture-focused and folklore content (Q13–Q16)

Table 10 Ordinal logit results for artifact-related content and non-informational content (Q17–Q20)

Table 8 presents the models for content categories associated with historical narratives: War History (Q9), Historical Daily Life Scene (Q10), Historical Background/Origin (Q11), and Historical Figures/Stories (Q12). These outcomes correspond, respectively, to the inclusion of historical war events, everyday life scenes, origin/background information, and notable figures in the projection content.

From Table 1, several notable relationships emerge. For War History content (Q9), two predictors are particularly salient: heritage designation level (Q5) and age of architecture (Q6). The coefficient for Q5 is positive (1.897, p = 0.003), indicating that sites with lower heritage status—such as general tourist attractions compared to World Heritage Sites—exhibit significantly higher log-odds of falling into a higher War History category. In practical terms, this means that lower-status sites tend to feature substantially less war-related historical content.

Conversely, the age of the architecture (Q6) has a negative effect (–1.854, p = 0.005) on the War content outcome, meaning older heritage buildings (lower Q6 values) tend to include more war history content. In practical terms, important, ancient sites tend to incorporate war historical narratives, whereas more recent or less historically significant sites usually exclude war history content. This pattern is visualized in Fig. 15: at World Heritage sites, war-related stories are often present (only ~12% of such cases have no war content), whereas at lower-tier heritage sites virtually all projection content avoids war history (over 60% have “None” for war content).

Fig. 15: Proportion of war history content across heritage evaluation levels (Q5).

This figure illustrates the distribution of war-related historical narratives within projection mapping cases, grouped by different levels of heritage evaluation (Q5). Blue bars indicate lower levels of emphasis, while red bars represent higher proportions of war history content. The comparison highlights how the presence of conflict-related narratives varies across heritage interpretation contexts.

For historical background and origin content (Q11), referring to explanations of a site’s history and origins, heritage designation (Q5) has a significant positive effect (β = 2.026, p = 0.003), while building age (Q6) shows a significant negative effect (β = −1.180, p = 0.043). This indicates that older and higher-status heritage sites are markedly more likely to incorporate background and origin narratives, whereas more modern or lower-status sites tend to feature such content less frequently. This pattern aligns with the expectation that sites of greater historical significance emphasize their origin stories.

Historical figures content (Q12) is significantly influenced by the spatial context of the building (Q4). The positive coefficient for Q4 (β = 1.598, p = 0.026) suggests that projection shows on standalone monuments (coded 1) are more likely to include historical figures or legendary narratives, whereas central buildings within larger complexes or fortifications (codes 2–3) are less likely to feature such themes, perhaps prioritizing other content types.

For historical daily life scenes (Q10), no single predictor achieves p < 0.05; however, the overall model fit is significant (LR χ², p = 0.0006), indicating that the predictors collectively explain variation in daily-life scene inclusion. The positive sign on exterior style (Q2, β ≈ 1.05) hints that modern architectural styles may correlate with reduced use of daily-life historical scenes, while the negative sign on heritage designation (Q5, β ≈ –1.28) suggests that higher-status sites may be more inclined to include such content. Although these effects fall short of conventional significance, they indicate a tendency for daily-life vignettes to appear more often in projection shows at historically important and traditionally styled sites. Across these historical content models, pseudo R² values range from 0.17 to 0.38. War History (~0.22) and Daily Life (~0.38) models show the strongest explanatory power, while the Figures/Stories model (~0.28) also reflects a meaningful relationship, particularly driven by spatial context (Q4).

Table 9 presents result for content types directly related to the architecture itself or intangible folklore: Architectural structure/construction (Q13), Historical appearance of the building (Q14), Mythical stories (Q15), and folklore/opera (Q16). These cover whether the PJM content highlights the building’s construction/structure, its past appearance, local myths/legends, or traditional folklore performances. Architectural structure/construction content (Q13) is significantly associated with facade preservation (Q8). The negative coefficient for Q8 (β = –1.567, p = 0.010) indicates that restored or reconstructed facades (codes 1–2) are more likely to feature structural or construction-related content, whereas sites retaining largely unchanged historic facades (code 3) tend to omit such material.

This pattern suggests that when restoration work is visually evident, projection designers may incorporate narratives explaining construction or restoration processes. Historical appearance content (Q14) shows a significant relationship with historical function (Q7). The negative coefficient (β = –0.676, p = 0.048) implies that administrative or residential heritage buildings (codes 1–2) are more inclined to present “then-and-now” visuals of the building’s form, while military or religious sites (codes 3–4) are less likely to do so, perhaps prioritizing other thematic elements.

Mythical stories content (Q15) is also influenced by historical function (Q7). The negative sign (β = –0.745, p = 0.032) indicates that as Q7 increases toward cultural/religious functions (code 4), the likelihood of such content being omitted decreases, meaning cultural or religious heritage sites more often include myths and legends in their projection narratives, consistent with their strong associations to traditional storytelling. For Folklore, Poetry, or Opera content (Q16), the dataset shows very limited inclusion across all cases (30 out of 36 coded “None”), resulting in quasi-complete separation (pseudo R² ≈ 0.999). Although the model fit is statistically significant (p = 0.001), coefficients are unstable and individual effects cannot be reliably interpreted. Practically, this indicates that such content is largely absent in PJM shows regardless of building attributes, and any subtle patterns cannot be robustly estimated from the available sample.

Across these architectural and cultural content models, explanatory power varies: pseudo R² values range from negligible (Q16) to moderate (Q13–Q15), with facade preservation and historical function emerging as the most consistent predictors.

Finally, Table 10 summarizes the models for content types centered on tangible cultural artifacts and the miscellaneous content: Cultural Relics/Sculptures (Q17), Paintings & Patterns (Q18), Traditional Costumes (Q19), and Projection content with no information (Q20). These cover whether the show includes imagery of artifacts/antiquities, traditional decorative patterns or text, ethnic costumes, and the proportion of purely aesthetic content without educational information.

In Table 10, traditional costumes (Q19) and paintings and patterns (Q18) are both significantly influenced by the building’s exterior style (Q2). The positive coefficients indicate that projection shows on traditional-style façades (wooden or tiled roofs, codes 1–2) are more likely to include traditional costume imagery and paintings or calligraphy, whereas modern facades (stone or glass, code 4) tend to feature such elements less often. This pattern suggests that when the architecture itself embodies traditional esthetics, the projection content is more likely to incorporate motifs and attire that reinforce the site’s cultural theme.

Cultural relics (Q17) content is significantly associated with the building’s historical function (Q7) (β = 1.002, p = 0.009). The positive coefficient suggests that sites historically used for military or cultural/religious purposes (codes 3–4) are less likely to include relic projections than those with administrative or residential functions (codes 1–2). For instance, fortress or temple shows may emphasize architectural narratives or symbolic stories over depictions of artifacts, whereas palace or museum-type sites more often project images of relics and treasures. The model fit is acceptable (pseudo R² ≈ 0.21) and the LR test approaches significance (p = 0.058), indicating a meaningful but subtle relationship. Non-informational content (Q20), purely decorative or abstract projections, shows no significant association with any measured building attribute. The model has minimal explanatory power (pseudo R² = 0.05; LR p = 0.81), suggesting that the inclusion of such content is shaped by factors other than architectural or historical characteristics, such as the artistic vision of the show or audience engagement strategies.

The ordinal logistic regression analysis is now complete, and the results indicate that attributes such as a building’s cultural status, age, original function, facade style, and preservation state collectively shape the thematic and narrative orientation of PJM content. High-status, historically old heritage sites tend to feature weighty narratives such as war history and origin legends; buildings with religious or cultural functions are more likely to incorporate myths and folklore, while military sites generally avoid such light-hearted content. Traditional facade styles are often paired with traditional art and costume elements, whereas modern-style facades tend to adopt abstract or contemporary visual schemes. Restored or reconstructed facades more frequently include content explaining the structure or restoration process, bridging perceived gaps in authenticity. These patterns suggest that PJM content selection is not purely driven by creative freedom but is closely coupled with the building’s physical and semantic attributes, with the architecture itself functioning as an implicit “directive” that sets boundaries and preferences for narrative themes.

From a design application perspective, this theoretical insight means that PJM creators can treat architectural context as a central design cue to enhance the cultural alignment and persuasive power of both narrative and visual expression. For high-status or historically rich heritage sites, designers should actively strengthen historical storytelling and the use of traditional symbols to highlight unique cultural connotations; for modern-style or functionally distinctive buildings, narrative motifs and visual languages can be adapted to match the architectural context; for restored or reconstructed heritage sites, incorporating a “visualized restoration history” can reinforce audience understanding of authenticity continuity. Such a context-driven creative logic not only improves audience immersion and cultural identification but also offers heritage managers a framework to anticipate and guide content direction, ensuring that PJM serves as a more targeted and sustainable medium for cultural communication.

Discussion

This study set out to investigate the relationship between architectural attributes and PJM content strategies in cultural heritage contexts. By updating and refining the timeline analysis method, categorizing architectural carriers, and expanding the PJM case database, the research provided both theoretical and empirical evidence to clarify how built heritage actively shapes cultural expression in projection design. The findings demonstrate that architectural structures and historical attributes exert a decisive influence on PJM content organization, guiding the distribution of information across carriers and reinforcing the functional roles of specific elements. Furthermore, the comparative analysis of cultural information across different carriers established clear tendencies: horizontally complex surfaces serve as primary zones of cultural narration, Asian-style roofs increasingly function as narrative anchors despite technical challenges, and historic walls or towers consistently frame symbolic performances. Collectively, these results substantiate the study’s central argument that projection mapping is not only a medium for artistic expression but also a framework constrained and directed by the cultural and structural logic of heritage sites.

Beyond empirical validation, the study also reveals an underlying tension in PJM design practice. Traditionally, designers have relied on professional expertise and aesthetic sensibilities, often prioritizing technical display and artistic novelty over contextual fidelity. The present analysis shows, however, that design decisions are inevitably tethered to the intrinsic attributes of the heritage environment. While stylistic freedom remains essential to creative practice, the representation of heritage culture follows discernible patterns that arise from structural forms and historical functions. More critically, if the design process in heritage contexts is detached from an interpretive engagement with the essential attributes of heritage itself, and instead guided only by subjective preference or aesthetic intuition, the outcome risks not merely artistic shortcomings but also the erosion of the seriousness and intellectual rigor that cultural heritage demands.

As a researcher, I have addressed models and data; yet as a designer, I wish to conclude by emphasizing the act of “seeing” heritage architecture. In PJM, the building is never a neutral screen but a collaborator—at times even a demanding director. Thus, design begins not with software, but with close observation: assessing structural stability, restoration conditions, and the surfaces that can or cannot sustain projection. Such attention prevents technical redundancies and aligns the narrative framework with the material logic of the building from the outset.

Equally critical is the cultural dimension. To disregard wars, rituals, or original functions embedded in the architecture is to risk superficiality or trivialization. Instead, the designer’s task is to amplify these latent cues through visual language. Different architectural typologies, accordingly, invite distinct narrative logics. Monuments and statues call for the perspective of historical witness, emphasizing gesture, materiality, and presence. Cathedrals and temples demand restraint, where verticality and silence become carriers of sacredness. City gates and towers embody thresholds, framing narratives of defense, power, and urban transformation. The practical implications distilled from this study are synthesized in Table 11, providing a framework for designers to align typological characteristics with narrative strategies. Ultimately, this study advances the principle that PJM design is not the imposition of an external story but the act of listening, discerning, and projecting the cultural voice already inherent within architecture. In this sense, PJM is never a “free canvas,” but one profoundly anchored in the material and symbolic attributes of heritage buildings.

Table 11 Design recommendations for PJM content narratives

At the final stage of this study, we summarized the logical limitations of our design and analysis. First, the dataset, although expanded to 36 cases, relies largely on secondary sources, and architectural typologies are intertwined with regional and cultural contexts (for instance, shrines and castles in Asia versus cathedrals and palaces in Europe). As a result, effects attributed to “type” may partly reflect regional traits, and future work should incorporate explicit region labels or adopt stratified or matched analyses. Second, independence and causal interpretation remain constrained. Many production companies are undisclosed and may recur across projects, introducing clustering that weakens case-level independence. In the absence of direct production-process evidence, the ordinal logistic estimates should be interpreted as associational. Prospective, production-side data and larger samples will be necessary to validate and refine these patterns.