Graphics in Urban Design – Possibilities of Hand-Drawn Images and Computer Techniques

Urban design covers a wide range of visual presentations ranging from the scale of the region, city to zone scale and public spaces. All these measures require a special graphical approach. The elementary part of the documentation at each level is an overall masterplan with all the attachments. Graphic design at scale 1:1000 – 1:2000 is probably the most favoured among the urban studies design. The graphical form at this level balances between the diagramatical detail level of the whole city region, regional scale and the detailed solutions of the public spaces, which creates the ideal conditions for the application of special graphic expressions. One of the most distinctive zoning level scale attachments is the perspective view from the human level (Fig. 1). Both representations are able to express the urban design at varying scales, details, and impressions, and complement each other (Table 1).

Figure 1.

“Masterplan typically includes a series of themed drawings which together define the principal elements of a proposed development. These may include land use, built form, roads, communications, surface drainage, open space or landscape structure and construction phasing” [7]. The level of detail will depend on the purpose of the plan. Some are intended to stimulate development by presenting a vision, others are working documents that will guide successive stages of a commitment to development already made. Some masterplans are diagrams explaining key development principles, others are illustrative plans, as below, portraying the indicative layout of built forms and open space. How detailed the masterplan depends on its scale. In typical urban design student’s work, the scale is 1:1000, or 1:2000. “Although only general structural aspects about traffic, uses, building forms and open spaces can be recognized in an illustrative site plan 1:1000. It already allows aspects such as roofs forms, lot boundaries and basic statements about the design of outdoor spaces and public thoroughfares to be depicted” [8].

“The plans are normally oriented with north at the top, and shadows can enhance the sculptural effect of trees, topographical elements and buildings. Elements like vegetation and bodies of water are usually depicted in green or blue tones approximating their natural colours. Streets and squares should not be too dark because otherwise, they tend to visually shift to the foreground. Using different line thicknesses helps to establish a hierarchy of the elements of the design. The more important the item, the thicker its outline should be. If the light-dark contrast of all elements is insufficient and they merge together when viewed, the depiction must be revised” [9].

“The graphic representation of the plasticity of the urban structure, especially in typical urban scale 1: 2000 and 1:1000, has a wide range of expressions in integrated systems or styles or in partial combinations with the expression of each component alternatively. A well-thought-out match of all elements can feel harmoniously and in accordance with the concept of your own solution. The most important graphic means of expression are contour lines, water areas, greenery, architectural objects, pedestrian areas and trails, roads and parking, or tramway route. However, not all of these can be applied equally in a diverse urbanization environment with varying proportions of artificial and natural elements” [10].

In addition to considering the representation of individual components, it is equally important to consider the optimal way of graphic expression – processing technique. We currently have a wide range of hand and computer techniques to choose from. Each of them gives us the possibility to choose different colour interpretations. „Black-and-white drawings are sometimes more evocative than coloured plans, as more is left to the imagination. These images can inspire contemporary interpretations” [11].

Eye-level perspective is a typical vision of a space from the visitor’s view.

This type of perspective expression is being used most often “because it documents the actual space and massing effect of the displayed architecture” [12].

It shows mainly ambience, character of places and sense of scale between buildings. “Perspective drawings generally refer to the graphically demanding attachments of the documentation, and their utilitarian function in drawing documentation is often not appreciated” [13].

“Perspectives and visualizations provide help in reading and understanding the design, especially for laypeople. The pedestrian’s view illustrates the qualities of the open space, while the buildings remain relatively generic” [14]. “The format of the picture plane is important. Horizontal drawings with a ratio of 3:8 are generally best used to convey a landscape design. This shape, as well as being a dynamic proportion, tends to concentrate the mind on design by reducing the amount of paper dedicated to foreground and sky” [15].

“By choosing viewpoint and scene, the author can deepen his or her architectural and urban design by drawing attention to the structural detail he/she considers to be the most characteristic and is not sufficiently defined in the 2D drawing of the masterplan. The urban design perspective principle is to remain its level of awareness of the issue that is documenting in order to depict the basic mass-space design solution in a simple cubic way. The range of detail and staffage is chosen to specify the scale and functional use of the environment. Sometimes it is appropriate to use the staffage more significantly in an effort to characterize particularly lively environment full of traffic, life and people” [16].

„When sketching perspectives, the standpoint must be chosen in a way to avoid the similar distortion of the surfaces, the same convergence of lines, to achieve enough contrast and space in the drawing to avoid accumulation and overlapping elements – clarity of the artwork. In the drawing, we move from overall to detail, and we select the level of detailing according to the scale of the displayed space. Usually, we are also interested in the environment, and therefore we enhance the perspective view with greenery, trees, grassy and water surfaces, human figures, transport means, and so on. The drawing must be simple to support the composition” [17].

“The hand-drawn perspective remains a very effective way of conveying the intended character and feel of places, yet to be designed in detail, as they might be experienced at street level. It is familiar to most audiences giving an understandable impression of what is intended without having to resolve the architectural and landscape detail. Computer generated wire-frames or photographs are often used as bases for the drawings” [18]. A Higher level of the hand-drawn sketch is an urban sketching. “Urban sketching is a raw and pure form of art that requires drawing from life, rather than from photographs or the imagination. Behind each drawing is a story of what is happening before our eyes” [19].

Nowadays, when computers have become an integral part of architectural and urban practice, the question of the use of hand based technique design remains alive. These two different ways of processing the documentation go into direct confrontation, each having its supporters and opponents, their pros and cons (Table 2).

At present, computer design is preferred by most practicing architects and planners in the final design process. “The media usually portray architectural design as consisting of fancy visualizations, and the sketch is marginalized” [20]. Even strong advocates of sketching recognize the benefits of computer technology. “The computer undoubtedly greatly accelerates most aspects of architectural work and, together with being a tool of accurate and fast drawing, it is being used for analysis, testing and 3D prototyping before construction of the project itself” [21]. The need to respond to modern trends also resonates on the academic ground. Uhrík and Špaček [22] are of the opinion that the aim of contemporary architectural education should adapt to today’s state of the technology, focusing on digital technology as a basic element, but they add that technology can not be separated from the creative process – human must be a creative element, computer should be an analytical element.

Although computers have become an integral part of architectural creation, “all practicing architects are forced to sketch, at a very least when on site or when dealing with a client, because it is faster to draw a detail using pen or marker than a computer” [23]. Therefore, care must be taken to prepare students for both forms of graphic processing. “For an architecture student, it is important to know how to sketch by hand and use digital programs and to know when to use them. These are not mutually exclusive, sketches are sketched in the beginning, and computer models are formed later. The benefits of digital artwork are the facts that when design changes, one does not have to rework the entire artwork and the software can work with the model and evaluate data such as shadows, lighting, structure, and so on. The drawbacks of digital artwork are its time consuming and treacherous difference in the scale between paper and computer screen” [24].

But it’s not just the speed of creation, or the perhaps better understandable drawing format that makes the sketch unique. The ability to be creative with the use of computer technology without prior experience with manual technique is questionable. “Denying the benefits of a computer would be a poorly educated and damaging opinion. … At the same time, despite the recognition of the computer and digital technologies, we need to identify ways in which they differ from previous design tools. We need to consider the limitations and problems that they may pose, for example, to the mental and sensual aspect of the work of the architect. … A hand with a charcoal pencil, pencil or pen creates a direct connection between the object, its expression and the designer’s mind. A hand-drawn sketch, a drawing, or a physical model are created by the same mass of physical weight as the proposed object they embody, while computer operations and imagination take place in a mathematical and abstract world” [25].

Hand based technique as a natural act of embodiment of the human imagination has been there for thousands of years, and we can assume that the development of this ability still has a major impact today on our imagination and creativity. As Pallasmaa states: “… each act of sketching and drawing creates three different sets of images: a drawing that appears on paper, a visual image recorded in the memory of the brain, and the memory of the drawing itself” [26]. The unsolved question remains whether equivalent interconnections between the brain, the mouse, and the computer itself are taking place when creating computer processed images.

Hand based creativity also appears to be a necessary prerequisite for mastering and understanding the scale and the abstraction in computer based graphical processing. “The drawing is a code that can be understood, read and used by those concerned. Simulation, coding, scale and abstraction demand the selection of information to be included in the sketch drawing. Only the essence can be shown. The drawing constitutes a composition of a designed and reduced reality” [27]. Ability to draw, similarly to other skills, requires long training. Although the hand is not perfect, it fulfils an important role of uncertainty, which is completely neglected in today’s pedagogical philosophies and methods. The relation between the whole and the parts – in hand drawing or modelling, there is a two-way relationship and a dialectical continuum, on the other hand, the PC in its perfection tend to create the impression of fragmentation and discontinuity [28].

Hand based creativity and design are undoubtedly of a fundamental educational nature and its full acquisition should precede the acquisition of computer-based design experience. Perhaps the ignorance of this requirement may cause a gradual degradation of the graphical expression, which now takes the form of over-detailed photorealistic processing on one hand and often primitive diagrammatical views on the other. “In our modern society we become less and less critical of architectural drawings, taking computer-generated perspectives for granted as the default method of architectural illustrations. Too often these images do not stand up to scrutiny, and are constructed with insufficient attention paid to vanishing points and sightlines. Continuing development of computer software has changed method of sketching skill, and it is now relatively easy to create perspectives, or plans, of a scheme” [29]. But an important communication role remains for perspectives drawn by the architect, where the benefits of being able to produce a freehand perspective should not be underestimated. It is intellectually dynamic to watch an idea drawn up quickly in 3 dimensions, and semi-realistic views often help steer the concept at a fast pace in the early stages of a project when ideas under formation are fragile and can be subject to misunderstanding.

Insufficient learning of hand-made work is also felt by students: “Being the head of fine arts institution gives me the chance to see student’s drawings all the way from their entrance exams up to graduation, and when I asked architects, teachers and students what students of architecture lacked most of all, the unanimous answer was: the ability to create a quick sketch, to formulate basic ideas through a drawing, to formulate space, floor plans, details, etc. in a clear and simple manner” [30]. “Working sketches and sketches of building details are often incomprehensible to a person other than the author himself, and therefore they do not appear in publications and the authors themselves have no reason to hide and publish them. It is also obvious that the sketches answer the habits of the work of each architect. The sketch is a very personal tool and the handling of it corresponds to that. Some architects like to present their sketches, others keep it hidden for themselves from the world” [31].

Some authors feel the computer era crisis so intense that they even tend to think that sketch should not be replaced by a computer at all. The perspective sketch is an established way of depicting one’s vision of spatial dimensions, which should not be deformed or replaced by mechanical axonometry.

At this level, the averaged values of 3 evaluators for the masterplan as well as for the urban perspective from the human horizon were compared. The range of rating was chosen from 1 to 5 (5 is the best). Based on the comparison of averaged ratings, the categories with the best and worst ratings were selected as well as the highest differences between hand and computer based processing techniques. When assessing the fundamental differences in the results, we took into account those results where the point of difference was at least 0.5 (highlighted in the table by pictogram).

In order to better understand the relationships between the different categories, the relationships between them were evaluated in the second step using the statistical method of the correlation analysis. For this purpose, Pearson’s correlation coefficient, which was calculated using Microsoft Excel 2010 using the (fx CORREL) function, was evaluated. Interpretation of correlation coefficients (R) was evaluated on the basis of Cohen [34]. Only statistically significant results with a correlation coefficient ranging from R = 0.5 to R = 1, and from R = -0.5 to R= -1 were taken into account. In the work, the most relevant results are described in more detail from the point of view of the authors, ie those in which logical interpretation was possible, mainly because the further verification of results by means of other methods was not carried out.

Most of the correlation results were similar for both types of graphical presentation of the masterplan – hand and computer based techniques.

The First Impression category correlates with the Differentiation of Lines of Terrain and Surfaces (R = 0.53), Hierarchy of the Spaces (R = 0.61) and Overall Rating (R = 0.65). Interesting and logical in particular is the relationship between the Hierarchy of the Spaces and the First Impression. It suggests that the graphical presentation of the Hierarchy of Spaces showing the diversity and clear relationships between zones, has a major impact on the first impression of the masterplan. This relationship also favours the correlation between First Impression and Differentiation of Lines of Terrain and Surfaces, as well as the need to clearly distinguish spaces of a different program. The importance of these relationships underlines the relationship between First Impression and Overall Result.

The Differentiation of Lines of Terrain and Surfaces category, except for the above-mentioned correlation with First Impression, also related to the Overall Rating (R = 0.61). The Hierarchy of the spaces category (R = 0.56) also correlated the Overall Rating, confirming the considerable impact of these categories not only on the First Impression but also on the overall result.

In addition to the above-mentioned correlations, the Hierarchy of Spaces was also related to Clarity category (R = 0.51). The relationship between categories of Hierarchy of Space and Clarity, is an expected positive finding, confirming the important role of reading spaces and their program easily in order to understand the design as well.

Category Static Traffic was related to a Small Architecture category (R = 0.55) and to Overall Result (R = 0.58). It can be assumed that the observed dependence on Small Architecture was related to the understanding of the scale in the space. Thus, a detailed rendering of Static Traffic, as well as a Small Architecture, reflects a better understanding of the scale and the need to capture appropriate details.

The category of the Differentiation of Greenery was related to the Overall Rating (R = 0.65).

In addition to the already mentioned dependence on Static Traffic, the Small Architecture category also had a relationship with the Overall Rating (R = 0.71), indicating that the detailed rendering of small objects has a positive effect on the overall impression and understanding of the design.

In the computer processed masterplan, the 3D Effect category correlated with the Hierarchy of Spaces (R = 0.53) and Overall Rating (R = 0.74). It indicates that there is greater variability in masterplan processing and better possibilities of working with shadows or morphology of the terrain.

In general, for both the graphical processing of the masterplan, the Clarity Category, in addition to the Hierarchy of Spaces, was also related to the Overall Rating (R = 0.49). The most significant connection to the Overall Rating had the 3D Effect category (R = 0.74), Small Architecture (R = 0.71), Differentiation of Greenery (R = 0.65), First Impression (R = 0.65) and Differentiation of Lines of Terrain and Surfaces (R = 0.61). With the exception of the First Impression, these are the categories that affect the detailing of the masterplan, so it can be said that adequate detailing has a major impact on the Overall Rating of the masterplan.

Probably due to the relatively low number of categories for perspectives, the correlation analysis showed a correlation between all of them. On the other hand, some relationships have proved to be stronger than others. An example is a category of Clarity that has a high impact on the First Impression (R = 0.72) as well as the Space and Massing (R = 0.78) and the Overall Rating (R = 0.81). This finding shows the need for a clear presentation of the perspective for an independent observer that easily understands where the perspective standpoint is located in the project. At the same time, it confirms that the need to think carefully about the entire scene and appropriate choice of the view into the main composition spaces are crucial in perspective views. Further results have confirmed that the characteristics of objects and surfaces are the domain of hand based techniques. The hand can freely and quickly illustrate floors and windows of objects or hatching the surfaces and pavements. Correlation has shown that in digital visualizations the detail is focused on the staffage such as people, cars or greenery and miss the object and surface finishing and details.

An interesting observation is a link between the Differentiation of Greenery in the masterplan and the categories of perspective views – First Impression (R = 0.53), Clarity (R = 0.52) and Overall Rating (R = 0.57). These dependencies are probably related to a sense of detail, on which the comprehensible rendering of the nature of the greenery is quite dependent. It is therefore assumed that a student able to distinguish relatively subtle differences between formal (alleys and tree lines), natural (wild and varied greenery), park, protective or special types of greenery, has a prerequisite for a better graphic presentation of the perspective view.