The Conceptual Model Mediated by IVR and 3DP as a First Architectural Idea Generator

Abstract

The first ideas generation of the architectural project has traditionally been carried out through sketches. Even though in recent decades models have also gained importance, their use is still restricted due to the time required to make them and their difficulty of realization when it comes to complex forms. This research argues that the use of concept models mediated by two disruptive technologies such as Immersive Virtual Reality and 3D Printing can foster the cognitive process of the ideation and configuration of the first architectural ideas. To demonstrate the hypothesis, a pilot study was conducted with 32 architecture students; 17 students created models manually and 15 used IVR and 3DP. Two observation sheets were used to collect information. The results show that in the process of generating ideas, the group that used the two technologies developed three of the four characteristics of the cognitive process better, being an undecided and slow process, then fast and continuous, and finally perceptual for reinterpretation. Also, both technologies complemented each other and favored the development of an intense, tactile, and phenomenological experience. Finally, regarding the model as a product, a better result was found in 3D-printed models in terms of two of the three characteristics, three-dimensionality complexity and materiality. It is concluded that these two technologies ideally complement each other as mediating tools for three-dimensional architectural thinking, making it possible to use the conceptual models as the first generators of the architectural idea.

1. Introduction

The conception of the first architectural idea occurs in two successive phases, ideation and configuration. In the ideation phase, the first ideas are generated, and in the configuration phase, such ideas are concretized in architectural figurations [1]. This process has traditionally occurred through drawing. Models could also have been used as the first generators of the idea if their construction occurred with the same naturalness and ease with which sketches are made [2]. These special feature models are called concept models, and only in the last decades have they started to be used more frequently, becoming even a sign of professional or vanguard credentials of the most prestigious architectural firms [3]. However, when it concerns ideas involving complex forms, the construction of a model becomes a difficult task to execute, which may require the mastery of some special fabrication technique or simply require a lot of execution time. This research seeks to recognize the advantages and disadvantages of the use of a conceptual model mediated by Immersive Virtual Reality (IVR) and 3D Printing (3DP). For this purpose, an empirical study was designed with architecture students divided into two groups: one using traditional manual modeling techniques and the other using IVR and 3DP. Observation sheets were used to record the creative process and the characteristics of the final models to allow for a comprehensive comparative analysis between the two methodologies.

2. Literature Review

2.1. Architectural Idea Generation Using a Conceptual Model

Conceptual models, also known as conception models or sketch models, serve as sketches or conception drawings in the process of the ideation and configuration of the first ideas of the architectural project, so they are also known as three-dimensional sketches [4,5]. In this regard, the cognitive process of the creation of the first architectural idea through a model shares with the process of drawing the same phenomenological condition and its four characteristics [6]. It is important to recognize the condition and characteristics that have led the concept model to be an important competitor to conception drawing today. Understanding this will then allow for being critical of technological incursions that may affect the creative process.

2.1.1. The Phenomenological Condition

The creation of models has been shown to play a significant role in the construction of the experience of knowledge [7]. That experience in direct relation to the human body not only allows for understanding the three-dimensionality of the spaces in the model [8] but also creates a phenomenological experience [9]. The development of creativity from the experiential realm is achieved through the manual creation of models [4]. Modeling like drawing involves actions and reactions of highly subjective, sensitive, and emotional content that are sustained by the haptic relationship between the object and the subject. The hands complement the sense of sight and the rest of the senses to fill the material with authenticity [10] and create the phenomenological experience. Subtracting this condition from the creative process breaks the intuitive and emotional connection between the designer and the model, resulting in more generic and less sensible designs that lack the depth needed to create meaningful spaces.

2.1.2. Characteristic 1: Undecided and Slow Modeling

The ideation process at first is a slow and progressive process that is full of doubts and based on indecision [11]. Since the idea is not completely defined, its creation does not seek to arrive at a final answer but rather to make the modeled objects elements of creation and the organization of ideas [12]. Moreover, this process must eliminate the superfluous elements to show the idea in its pure and abstract state [13]. This abstraction effort in search of the guiding idea then becomes its goal [14]. As in drawing, deliberate or accidental indecision or indeterminacy allows for preserving alternatives while retaining a deliberate ambiguity [15]. Thus, the first moment of the cognitive process is slow and indecisive in the choice of forms and materials. In computational modeling processes this reflection is either eliminated or accelerated to the point where it results in the less in-depth exploration and evaluation of alternatives, resulting in less thoughtful and potentially less relevant ideas.

2.1.3. Characteristic 2: Rapid and Continuous Modeling

After the first moment, the cognitive process itself opens up to many possibilities, which must be caught quickly in order to capture the rapid flashes of mental stimulation [16]. The process then becomes fast and continuous, and for that purpose, it uses the size and the elementary. The small size of the models not only allows for a fast modeling process but also allows for processing the visual image with maximum detail due to the visual field [15]. This means making models that may well fit in one hand [17] or are never larger than 15 × 15 cm [14]. On the other hand, elementary implies simple and experimental objects [18], and even if high three-dimensional complexity is required, one should look for unfinished and imprecise objects that can be changed and reshaped quickly [3,18]. Although the manual process of creating conceptual models itself often does not achieve the multiplication that allows new ideas to be captured and explored quickly for the continuous and dynamic development of the design, it is necessary to recognize its importance, as the prestigious Office of Metropolitan Architecture (OMA) does when they state that they start with a conceptual model of the building that can then easily grow to 30 or 50 models [19].

2.1.4. Characteristic 3: Perceptual Modeling

The process of modeling the idea, as with the act of drawing, at some point becomes a perceptual act that seeks to interpret new meanings based on what was previously created [20]. The importance of creating ideas with models lies in the degrees of imprecision, undefinition, and suggestive indeterminacy that allow for reflection, exploration, and inspiration towards alternative designs [21]. The perception of the material delimiting the emptiness and the effects of shadows and light can only be given by observing and touching the model [8,14,22]. The perception of the material itself with which they have been made allows for analyzing their physical characteristics [23] and their connotations or meanings that can give a new context to the architectural idea [14]. Subtracting this characteristic from the creative process could limit the ability to interpret and reinterpret the design, reducing the opportunity to discover new possibilities and contexts for the architectural idea.

2.1.5. Characteristic 4: Confrontational Modeling

At the end of a cycle of the cognitive process, it is necessary to finish configuring the idea to discuss it or take it up again at another time. Unlike the act of drawing, which configures through rudimentary representational drawings, the model has the advantage of representing the space in its three perceptible dimensions from the first volume created [18]. However, the final configuration that allows for self-confrontation and confrontation with others, supported with spoken discourse [24,25], is achieved by sharpening visual and tactile perception and making final readjustments of the position, relationship, and materiality. The confrontation will allow for revealing gaps in the idea and opening criticism and discussion. It will also allow for clarifying erroneous conclusions about the intention of a project [3]. All this will allow for continuing the cognitive process in the next cycle.

2.2. Characteristics of the Conceptual Model

Conceptual models, as opposed to presentation and working models [18], are important tools in the ideation and configuration phases of the first ideas of the architectural project. This allows for materializing in a tangible, three-dimensional, exploratory, and preliminary way the fundamental ideas and concepts underlying the architectural proposal to be evaluated, discussed, refined, and validated before continuing with the next phases of the creative process. As with the process, it is important to recognize their following characteristics as finished products to understand the advantages and disadvantages when compared to other manufacturing methods.

2.2.1. Representation of Three-Dimensionality

The main characteristic of any physical model is that it offers the unique possibility of representing space in its three perceivable dimensions. This in the conceptual model allows for a direct understanding of space, which is more relevant when dealing with complex shapes [26]. Because of its small size and easy handiness, it perceptually approaches axonometry, which allows for a dynamic perception of its views vistas [14,27] and the discovery of new possibilities and potentialities of architectural space [23]. Finally, in the perceptual process of its three-dimensionality, views and volumetric relationships emerge out of what is anticipated, promoting and developing a more intense creative process [28].

2.2.2. Representational and Experiential Materiality

Another characteristic that is as or more important than three-dimensionality is its material and volumetric sense, which gives rise to other senses such as touch and “physicality” [4,27]. This allows for a tactile and sensory understanding of the materialized idea that enables direct experiences because light is seen by perceiving shadow and emptiness is understood by detecting matter [22]. The qualities of materiality allow one to explore correlations between different forms, between forms and illumination, and between forms and emptiness [23]. Furthermore, the choice of material for its own connotations or meanings gives it abstract qualities [14] that transcend the merely visual qualities, allowing for a sensory and haptic experience that influences the conception.

2.2.3. Conceptual Abstraction

These models encapsulate the conceptual essence by concentrating on the visual representation of fundamental ideas without detailing specific elements. It reveals the essential and avoids the superfluous in order to focus on the only thing that is proper to the architect: reason, matter, and light [22]. Its small size facilitates this approach to abstraction, presenting itself as a synthesis and constituting the physical materialization of the architectural idea in its pure state [13]. Abstraction confers a certain formal autonomy inherent to sculptures that makes it a more or less a precious object [14]. This abstraction facilitates effective communication and allows for a more flexible interpretation of the conceptual vision, highlighting the importance of physical materialization in expression.

2.3. The Digital Model

The digital model is an accurate, detailed, and three-dimensional computerized representation of an architectural object created by 3D modeling software that allows for visualizing, analyzing, and modifying the object before its physical construction. Its visualization and modification are carried out through interfaces displayed on the computer screen and data entry via the keyboard and mouse. Its main advantage, which has led it to almost displace the presentation model completely, is its accurate and realistic representation of three-dimensionality and materials. Despite its wide range of qualities and advantages that continue to transform the practice of architecture, digital modeling is not yet an important possibility when it comes to constructing models at the conceptual level, i.e., at the first stage of the creative process, for the following reasons. Its lack of materiality [29] and tangibility [30], or, as others call it, physicality [27], detract from the phenomenological experience and the haptic and direct experience with materiality [10]. Although there are now software that offer a high degree of manual control over the modeling process, which is ideal for creative and artistic tasks, such as digital sculpture and 3D animation (Zbrush and Blender, among others), most of them offer a high degree of geometric control [29] and high mathematical precision [30], making digital modeling a deterministic process that operates in a limited solution space and with predefined options [21]. This added to its immediateness and contrasts it with the indecisive and slow reflective process needed to achieve effective abstraction [10,22]. While this immediacy allows for the easy duplication and modification of models, it is not the iteration that confers advantages in the intuitive, rapid, and continuous creation process [23,31]. Finally, the perception and confrontation of the three-dimensional idea through a computer screen is effective, but not as effective as the tactile perception of the physical model.

2.4. The Virtual Model

The virtual model is also a digital model, so it shares with it all its characteristics, with the following differences. The visualization and manipulation of the objects take place in an immersive environment, which allows for realistic immersive experiences of full-scale designs for a better perception of the three-dimensionality and interaction with the object. For this reason, most of the 3D modeling software for architecture (Autodesk VRED v2024, Iris VR Prospect v1.0, Enscape v3.5, and Graphisoft BIMx v2023, among others) have their version for IVR. However, these versions are mainly focused on visualization as the digital models are created in digital modeling software and exported to the virtual environment where they can be modified, but with very little possibility of creation. Although other software allow for the creation of volumes, they maintain the characteristics of high geometric control and mathematical accuracy. For these reasons, the choice of software is important [23]. Some studies have used more artistic than architectural software to explore its creative potential for the early stages of the architectural design process [32]. For example, software designed exclusively for creating in the immersive environment such as Tilt Brush, Gravity Sketch, MasterpieceVR, Quill, or Blocks (2023 versions) offer the advantages of the free creation of strokes and objects in direct relation to hand and body movement [32], where geometric control or mathematical accuracy is not required. These characteristics foster reflection through indecisive and slow modeling, leading to conceptual abstraction, and foster rapid and continuous modeling due to the ease of creation. Although it is true that a phenomenological experience cannot be fully given in the virtual environment, it comes very close thanks to the movement of the body and hands, with the haptic controls fulfilling that condition. Finally, despite not having physicality, which avoids the haptic experience of the material, the representation of materials that foster conceptual abstraction can be very useful.

2.5. The 3D-Printed Model

A 3D-printed model is a three-dimensional physical representation of an architectural object created by means of three-dimensional printing technologies that allow for a tangible interaction of the architectural structure and thus a better spatial understanding of it. Since every 3D-printed model has its origin in a digital model, it adopts the advantages and disadvantages of the digital modeling process described above. However, the main advantage of the model as a final physical product is its tangibility, which distances it from the digital and virtual models and puts it on a par with the hand-built model. In this way, the 3D-printed model fully meets the first two characteristics of the conceptual model: the representation of three-dimensionality and the representational and experiential materiality. However, this last feature does not yet take advantage of the technological development that allows for printing in translucent and color resins, in filaments with stone, metal, or wood-like finishes, or in materials that are on a par with translucent micas, balsa wood, or textured cardboards, which achieve such good results in the execution of manual conceptual models. Another important advantage is the ease of materializing complex shapes that are very difficult to create manually. This 3D printing capability allows designers to move forward with any idea regardless of its complexity [26], removing the limitations imposed by traditional manual modeling techniques. With 3D printing, architects can explore intricate geometries and precise details that would otherwise be too laborious or even impossible to build by hand. Finally, conceptual abstraction, which is the third characteristic, is not fed by a reflection process when it is created digitally; therefore, 3D printing does not improve it either [21] because the manufacturing process is completely detached from the hands and time of the creator. This can end up producing fascinating objects that have “escaped” from the computer screen without any concept to support them [29]. In addition to this disadvantage, there is an attitude of visualizing the printed models as a final product, and there is a lack of a sense of scale as a conceptual resource [30].

3. Hypothesis

The weaknesses and strengths offered by digital technologies such as digital models, virtual models, and 3D-printed models compared to those of the traditional physical model are summarized in Figure 1.

This research argues that the cognitive process of the ideation and configuration of the first idea of an architectural project through a conceptual model can be fostered with the incorporation of two disruptive technologies that complement each other to obtain all the advantages of manual modeling and models (see the green route in Figure 1). The first technology is Immersive Virtual Reality (IVR), which, in addition to fostering the quick and easy creation of strokes and volumes with the simple movement of hands equipped with haptic controls, allows such creation to be a phenomenological experience. Furthermore, it fosters the perception and understanding of the shapes and spaces created by allowing the immersive environment to easily change scale, which allows for immediate reinterpretations. The second technology is FDM 3D printing, which is low-cost, very precise, and fundamentally very versatile for manufacturing objects of complex geometries. This technology, among other advantages, fosters and creates the haptic link with the materiality of the object, a major disadvantage of all digital models including the virtual one. Moreover, by allowing the physical and three-dimensional materialization of the idea, it provides it with all the advantages of the manually manufactured model. The following hypotheses are proposed:

H1: 

The integration of the IVR in the process of the ideation and configuration of the first architectural idea through a virtual conceptual model not only shows similar characteristics and conditions as the same traditional process with physical conceptual models but also favors the quick and easy creation and modification of multiple forms and volumes, making such creation a phenomenological experience. Students using IVR are expected to have a higher number of iterations and modifications to their conceptual models due to the ease of virtual manipulation through hand and body movement compared to students using manual techniques.

H2: 

The integration of 3DP in the materialization of the first architectural idea not only helps to produce physical models with similar characteristics as the manually produced conceptual models but also favors the more accurate creation of three-dimensionally complex forms. 3D-printed models are expected to exhibit greater three-dimensional complexity, allowing for a better spatial and tactile understanding of architectural ideas compared to hand models.

4. Methodology

The pilot study was carried out with students of the Architecture course at the Universidad Nacional de San Agustín de Arequipa in Peru. It has been focused on the analysis of the phases of the ideation and configuration of the first idea of a small architectural project within the subject “Architectural Design Workshop 1”. The students were divided into two groups: one using traditional manual modeling techniques and the other using IVR and 3DP. Each group developed conceptual models from an initial architectural idea. Observation sheets were used to record the ideation and configuration process and to evaluate the characteristics of the final models. The evaluation criteria considered four process characteristics and one phenomenological condition, and the final model evaluation criteria considered three characteristics.

4.1. Participants

For the experimentation, the 33 students in group B of the subject were divided into two subgroups. The division was random but maintained equity in terms of their academic performance, as reflected in their grades in the first part of the subject. This ensured that the inequality of prior learning did not distort the results of the experiment. For the final selection, Google Forms was used to determine who met the following archetype: students who were taking the subject for the first time, who had not used virtual reality glasses before, who did not suffer from color blindness, who did not suffer from migraines, and who did not have an easy tendency to dizziness. With this information, the experimental group consisted of 15 students, made up of 7 females and 8 males, with an average age of 17.8 years. The control group consisted of 18 students, made up of 13 women and 5 men, with an average age of 18.1 years. For their participation, the students signed a consent form endorsed by the Ethics Committee of the university.

4.2. Instruments and Materials

Two observation forms were created for data collection. Observation Sheet 1 was designed to observe the behavior of the students during the process of generating the architectural idea through the construction of a conceptual model. The experimental group was observed in the virtual environment, and the control group was observed during the manual construction of the models. The five aspects observed and shown in Figure 2 are directly linked to the single condition and the four characteristics explained in Section 2. The evaluation was carried out through a five-level Likert scale.

Observation Sheet 2 was designed to observe and evaluate the presentation of the model as a final product in both groups. The three aspects referred to the three characteristics of the conception model explained in Section 3 (Figure 2). The evaluation was also carried out with a five-level Likert scale.

The IVR equipment consisted of two HTC Vive Head-Mounted Displays (HMD) along with their haptic controls, which are controls that allow for tactile interaction with the virtual environment. This hardware is complemented by two Intel Core i7 PCs with a NVIDIA GeForce RTX 3080 graphics card and 32 GB RAM and two 65” TV screens. All the IVR equipment is installed in two rooms of 7 m² each exclusively for IVR experiments. The software for the 3D modeling was Google Blocks. This application was chosen because it was created exclusively for freehand modeling using haptic controls with moderate geometric control and mathematical precision. While its modular nature might limit creative freedom, two other aspects influenced its choice. First, it is a tool with a relatively low learning curve, which facilitates its integration in a short experimentation. Second, unlike other applications such as Tilt Brush, Gravity Sketch, or Quill, the models exported from Blocks are accepted by 3D-printing applications. Finally, for 3D printing, four Creality filament printers and the Ultimaker Cura software (v 5.3.0) were used to set up the print. For the work with the control group, the workshop classroom was used for the development of the subject.

4.3. Experimental Design

The experimentation consisted of the materialization of the first idea for a tourist pier and viewpoint on the banks of the Chili River in the city of Arequipa through a conceptual model. The 33 students, after the analysis or pre-design phase, proposed the first idea of the project in a workshop. This idea was executed through freehand drawings on an A3 sheet of paper. Once the teachers’ feedback was finished, they were called together three days later to finish the ideation and configuration of the first idea through a conceptual model. The specific task was to build a conceptual model of the tourist pier and viewpoint without a specific scale on the ground model measuring 20 × 20 cm. This conceptual idea had to consider three spaces: the reception, the viewpoint, and the pier. The model was to be white on the brown ground. To carry out this specific task, the experimental group worked separately in two sessions as follows.

In the first session, the experimental group underwent training in the use of the HTC Vive HMDs with haptic controllers and the “Google Blocks” software (v 1.0) within the Digital Design and Fabrication Lab. The students learned how to create 3D objects in a virtual environment using only the six available tools of the software: Shape, Stroke, Eraser, Grab, Paint, and Modify. With the shape tool, they created various types of polyhedral and curved surfaces such as cones, cylinders, and spheres. With the stroke tool, they created freehand strokes, and with the modify tool, they transformed the constructed objects. This application is very simple, with no texture effects or special lighting, but it is sufficient for the purposes of the experimentation. Each student used the HMD and software for 20 min, which ensured the mastery of the tool.

In the second session, which took place in the virtual environment, the students were reminded of the task to be carried out, which had been explained two days before. Each student used the hardware and software (as shown in Figure 3) for 60 min, with a 5 min break in between. Since the location of the pier was on the banks of the river, it was pertinent to have the terrain modeled schematically and introduced into the virtual environment so that each student could take it into consideration when generating the idea. The indication for the first part of the session was to start with the exploration of three-dimensional shapes considering the modeled terrain. It was also indicated to leave a record of the whole process and not to erase the initial strokes or shapes. Figure 4 shows four examples of the different alternatives generated in the creative process by the students on the brown terrain. After 25 min, there was a five-minute break. After that, the indication for the second part of the session was to recognize and observe the previously created shapes, use the scale tool, and then correct, increase, or eliminate the shapes and finalize the best idea. During this session, the Principal Investigator applied Observation Sheet 1 for 60 min.

Finally, the recorded file of the virtual model with the extension “obj” was imported to the Ultimaker Cura software to configure the 3D printing in the four Creality filament printers in the laboratory. The average printing time for each file was 2 h, which took 7 h in total. Figure 5 shows some recently printed parts.

On the third day, the students in the control group were called to create their conceptual model, but in the traditional way using cardboard, sticks, micas, etc. They performed the task for 90 min, and the Principal Investigator applied Observation Sheet 1. After that, the students of the experimental group joined the control group to give them the 3D-printed pieces. At this point, both groups were instructed to finish and present the models in an additional 30 min. During this time, the experimental group was asked to arrange and fix the 3D-printed pieces on the terrain model that was previously laser-cut on cardboard. Figure 6 shows three examples of 3D printed models placed in the terrain. Finally, for the evaluation of the conceptual models, each student was asked to present their conceptual idea for 3 min. For this, they had to use the final physical model (hand-made or 3D printed) to help explain the reasons for the choice of forms and location. During the presentations of the students from both groups, the first-year architect teacher, an expert in architectural design, applied Observation Sheet 2. Figure 7 shows the manually created and 3D printed models before the presentation.

A synthesis of the process using IVR and 3DP is shown in Figure 8. First the model created in IVR is shown, then exported and opened in .obj format, subsequently configured for 3D printing. Finally, the 3D printed parts and the finished models are shown and presented to be photographed.

5. Results

Observation Sheet 1 gave the results shown in Figure 9. Regarding the observation of the intense movement of the hands, arm, and body during the creation of the model, a very high level was found in the experimental group (4.8) compared to the control group, which was only moderate (2.9). The second observation that focused on the creation of shapes and volumes only with the intention of inquiry resulted in a very high level (4.7) in the experimental group, while in the control group, it was only high (3.3). As for the third observation for determining the easy creation of multiple shapes and volumes, the most outstanding difference between the two groups was found. The experimental group has accomplished this at a very high level (4.8) compared to the moderate level (2.7) of the control group. The category that was related to observing and perceiving what was initially created to reorganize and make accommodations showed 4.9 points compared to the 2.9 rating of the control group. Finally, the last category that observed the use of the model to verbally confront the professor with the conceptual idea has given very similar values in both groups (4.2 vs. 4.0).

The results of Observation Sheet 2, which focused on the final model as a product, can be seen in Figure 10. Regarding the three-dimensional complexity of the model that needs to be understood by moving and observing the object, it has been found that the printed models have been more complex, which required more manipulation and observation (4.7) compared to the manual models that have been simpler (3.5). As for the materiality of the model, those of the experimental group have induced a little more to be touched and to be observed with lights and shadows than those of the control group (4.5 vs. 4.1). Finally, the printed models ended up exhibiting greater abstraction and beauty as autonomous objects (4.3) than the hand models (3.9).

6. Discussion

Regarding the results obtained, this research validates the first hypothesis proposed. That is to say, the incorporation of the IVR in the process of the ideation and configuration of the first architectural idea through the modeling of a virtual conceptual model has shown not only similar characteristics and conditions as the same traditional process of building physical conceptual models but has also shown some important advantages.

In terms of the phenomenological condition, that is, the intense bodily experience that occurs throughout the creative process, it is in the virtual environment that a greater linkage of the creative process with bodily experience and movement has been generated. This assertion aligns with those who argue that this environment generates meaningful experiences [33] that challenge the phenomenological idea that the sense of bodily presence is anchored only to the physical body [34]. It should be pointed out that only body movement was recorded on the observation sheet; however, despite the fact that this was not a previously established variable, gestures and body expressions of astonishment and admiration, but also of reflection, judgement, and satisfaction, were observed with great incidence in the experimental group. This leads us to think about future research with brain–computer interface devices or others that allow data collection to be translated into more objective data. On the other hand, the complementation of the use of 3DP in the experimental group has completed the intense and corporal experience when they received their 3D-printed pieces to make the final adjustment, arrange them on the field, and take photographs under the sun. All this has generated a haptic link between the body and the hand with the created object [22], making the whole process a phenomenological experience.

Regarding the characteristics of the idea generation process, the interpretations are as follows. The first characteristic refers to the fact that modeling should be indecisive and slow, exploring, inquiring, and reflecting on the shapes. In the virtual environment, it has been easy to create free strokes and geometric shapes following the movement of the hands, and it has also been easy to modify them. Therefore, this inquiry and exploration have been very productive compared to those carried out manually because the construction demanded more time or became difficult when it came to complex shapes. Something similar happened with the second characteristic, which refers to the second moment in which, once the shapes have been explored, multiple variants begin to be created quickly. The virtual environment has fostered the easy copying, derivation, and modification of alternatives compared to the few manually generated alternatives. These two characteristics demonstrate that the limitations of design media can restrict thinking by influencing the way problems are explored and answered [27]. Regarding the third characteristic referring to the perception of the objects created to advance in the process of the materialization of the idea, a significant difference has been found. The virtual environment allows for scaling the objects so as to perceive them as a small sculptural object or as a very large building with the possibility of walking through it and even feeling spatial sensations [35]. This important quality allowed for a rapid readjustment of the objects, triggering a process of instantaneous reflection and feedback [22] that did not occur as intensely in the control group. Finally, the fourth characteristic that refers to the final modeling that allows for confronting the three-dimensional idea with others—in this case, the professor—has not shown significant differences. Despite this, the greater three-dimensional complexity of the virtual models has meant that the students use the model much more, moving it and rotating it to explain the conceptual ideas, as opposed to the manual models that, due to their three-dimensional simplicity, have not been manipulated much in the confrontation.

An important finding not initially anticipated relates to the length of time the creative process took. When the members of the control group were assigned the same time as the experimental group (60 min) to create the model, they had to be assigned 30 min more to finish the task because the models were very unfinished. Since the experimental group had completed the task the day before, it was no longer possible to equalize the times.

As for the second hypothesis, this research also validates it. The incorporation of 3DP in the materialization of the first architectural idea has helped to produce physical models that not only have similar characteristics as the manually produced conceptual models but are also superior in some respects. Regarding the finished and presented model, a better result was found in the three evaluated criteria in the models created in IVR and printed in 3D. In terms of the three-dimensionality and complexity of the shapes of the models, the models of the experimental group showed superiority over those of the control group due to the easy modeling of almost any form in IVR and their easy materialization with 3DP. In terms of materiality, it has been observed that the materiality of the white filament used has not been surprising in the printed models, but it has been enough to induce touch and manipulation to have a haptic experience superior to the models made with white cardboard. The use of other materials such as translucent resins for 3D printing or filaments finished with various materials remains to be explored. Finally, conceptual abstraction has behaved very similarly in both groups, but the better completion of the printed models, their complexity, and their materiality have conferred a status of a small conceptual sculpture over the manual modeling.

Two unanticipated findings were found in the analysis of the completed models. The first is related to the terrain models. Since the immediate context allows us to understand the spatial relationships of the designed object [36], the experimental group, having the terrain model present all the time, modeled on the basis of it and obtained more relevant proposals. This was not the case with the control group, which made little use of the terrain model in the modeling process, obtaining mostly models superimposed on the intervention terrain. The second is related to the quality of the models produced. It was found that the 3D-printed models of the experimental group showed greater accuracy and detail in complex three-dimensional shapes compared to the manual models of the control group. This was mainly due to the ability of the 3D-printing technology to handle complex geometries with high precision.

The weaknesses of the modeling process in IVR are as follows. First, there is the partial availability of hardware and software that is not available in every university or office. Unequal accessibility to these technologies can create a gap in professional training and practice, and these ethical concerns must be addressed to integrate these technologies in a sustainable and equitable manner. There is also the cybersickness, which involves symptoms similar to motion sickness, with nausea and light-headedness as a result of prolonged use [37]. Finally, there is a lack of the software for creating materials and textures (only colors can be assigned), as with other software such as Tilt Brush. This limits the conceptual ideas based on materiality.

The weaknesses of 3D-printed models are their difficulty to be modified and transformed after printing compared to models built with cardboard. This affects thedisposable and modifiable quality of conceptual models arriving, after many iterations, at a final answer. A second weakness is the choice of material to make the model. The impossibility of using any material other than the printing filaments limits the choice of materials that, by their connotations or meanings, can better express a conceptual idea [14]. The time demanded by 3D printing is time subtracted from the designer for reflection [22], but it is also a useful time for reflection on other aspects of design. Finally, as an emerging technology such as IVR, there is the ethical consideration of unequal accessibility to these technologies. This, in developing countries, may further widen the gap in professional training and practice.

The research was conducted with a relatively small group of students, which limits the generalizability of the results. A larger sample size could provide more robust and representative results. Another important limitation is that the assessment of the creative process and the final models was conducted using Likert scales, which may be subject to the subjectivity of the observers. This potential observer bias may have affected the assessments and thus the conclusions. To mitigate this bias, future studies will implement more objective assessment methods, such as additional quantitative and qualitative analyses, and the use of a wider range of measurement tools. Finally, the research was conducted over a relatively short period of time, which may not be sufficient to capture all aspects of the impact of IVR and 3DP on the creative process in the long term.

The findings are in line with existing literature suggesting that digital technologies such as IVR and 3DP can significantly improve the architectural design process [7,38]. The integration of these technologies not only facilitates the rapid creation and modification of conceptual models but also improves the spatial and tactile understanding of architectural ideas. The implications for the teaching and practice of architecture are significant. Incorporating IVR and 3DP into academic curricula can enrich the educational experience for students, providing them with advanced skills and a greater connection to the creative process. For professionals, the adoption of these technologies could significantly improve the efficiency and quality of architectural projects.

Despite the multiple advantages and the few disadvantages found, an integration of traditional techniques with digital tools that allow for broader, versatile, fluid, and creative processes is considered as the best alternative [39]. Regardless of the technological means used, the cognitive processes that have throughout history generated brilliant architectural ideas should never be altered.

7. Conclusions

The results of the comparison of two groups of architecture students ideating and configuring their first ideas of a small architectural project through conceptual models allow for concluding that the incorporation and complementation of the IVR and 3DP in that cognitive process have not only not affected it but have favored it over its similar one using manual models both in the process and in the final result.

First, the intense phenomenological experience generated in the virtual environment, reflected in the students’ body movement and expression, highlights a deeper connection to the creative process, including a greater connection to the creative process compared to students who did not use technologies. Furthermore, in the second moment, the haptic link with the 3D-printed object becomes tangible and direct since the pieces are taken by hand to assemble the model, place it on the cardboard terrain, and make the study for taking pictures under the sunlight. Both moments complement each other and constitute a phenomenological experience essential to generating architectural ideas that match or surpass the experience of the traditional process.

Regarding the four characteristics of the creative process of idea generation, it is concluded that in the first three, the use of IVR has fostered the cognitive process with respect to the group that materialized their ideas by building models manually. That is to say, the inquiry and reflection of shapes, the multiplication of alternatives and variants, and the perception of the shapes created to make derivations or corrections have been better developed in the virtual environment. In terms of the last characteristic, the difference has been irrelevant. The confrontation of the idea in front of the professor and using the physical modeling have been very similar.

Regarding the evaluation of the final models, it is concluded that due to the easy physical materialization of the models created in IVR, the models of the experimental group have stood out in their three-dimensional complexity, which has led to their more detailed observation. As for the representation of the materiality of the object, they have been very similar since they all used only white cardboard or filament. Despite this, the texture and the finishing of the 3D printing have led to a more direct manipulation and tactile experience. Finally, the conceptual abstraction has also been very similar, with the small difference that the models printed because of their complexity have stood out as small sculptural objects.

The implications of this research are significant for the field of architectural education and professional practice. The validation of IVR and 3DP as effective tools in the architectural ideation and configuration process suggests that their integration into academic curricula could enrich students’ educational experience, providing them with advanced skills and a greater connection to the creative process and spatial compression. The ease of exploring and materializing complex ideas in a virtual environment, followed by their physical realization through 3D printing, can foster greater innovation and creativity in architectural design. For professionals, the adoption of these technologies could significantly improve the efficiency and quality of architectural projects. However, a balanced combination of traditional and digital techniques is recommended to ensure a holistic creative process that does not rely exclusively on technologies but uses them as complementary tools that enhance the skills and knowledge acquired.

Future research could explore the long-term impact of these technologies on the architectural design process and their application in wider professional contexts. In addition, studies could be developed to evaluate the effectiveness of both technologies complemented at other, more advanced stages of the architectural design process, with larger samples and with groups with greater age and experience in both design and IVR use to determine whether age and experience influence the use of these new digital tools. And given the incursion of artificial intelligence (AI) as a powerful tool in architectural design capable of autonomously generating images and three-dimensional models, the combination of IVR, 3DP, and AI could further revolutionize the field, allowing architects to explore a wider range of innovative ideas and solutions. Future studies should investigate how the integration of these technologies can optimize the architectural design process and their practical applications in education and the professional field.

The integration and complementarity of IVR and 3DP have proven to influence the way design problems are explored and the way architectural thinking is realized. Their complementarity with traditional analogue procedures can turn the design process into a complete cycle that encourages the generative generation of architectural ideas with the potential to transform the way architects design.