Chapter Three. What s In A Freehand Drawing that the Modeling Tool Should Recognize

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1 30 Chapter Three What s In A Freehand Drawing that the Modeling Tool Should Recognize This chapter discusses what features of a 2-D freehand drawing that a 3-D computer modeling tool should recognize and how it should use these features to generate a 3-D model according to the recognition. This chapter is divided into three sections. Section 3.1. describes the role of drawings in the early design process. Section 3.2. looks at several fundamental features in a freehand drawing. Section 3.3. discusses the use of symbols in freehand drawings The Role of Drawings in Early Design Process In the early phase of a design process, architects draw what are commonly referred to as preliminary, initial, rough or conceptual sketches. These sketches may be of any drawing type (e.g. plan, section, elevation, or perspective), although the plan is most commonly used at this stage. Designers usually make preliminary drawings, which are invariably abstract diagrammatic, and highly conceptual, while some designers begin with more concrete but still loose studies of building forms, shapes, and appearances. Drawings in the early phase of design help designers communicate with themselves and clarify the thoughts in their mind. By constantly modifying, enhancing and refining images, designers transform a rough concept into a relatively developed proposal. Through handmade drawings, diverse concepts and relationships can be easily recorded, analyzed and refined.

2 The use of preliminary design drawings in the early phase of designing allows architects to quickly trace a number of initial design ideas they have in mind. These initial ideas can then be compared with one another or filed for further reference and modification. Early conceptual drawings offer intimate views into the designer s first thoughts during the design process. In addition, freehand drawings used in early design are usually deliberately experimental. They help document and give form to the initial process of inquiry. They are used to generate variations on themes and to produce series of alternatives that in the next phase of design will be examined and developed more thoroughly Fundamental Features in a Freehand Drawing The initial freehand drawings in a design process tend to be simple, experimental, and conceptual. Typically, those hand-made drawings only consist of some simple elements such as lines, simple geometric polygons (usually ovals or rectangles), and some text for labeling different functional spaces (Do, 1998). When designers start exploring the alternatives of spatial configuration according to the building program and the surrounding site condition, they usually decide the exterior building boundary first, and then arrange the interior spaces inside the boundary 1. Typically, designers draw lines in a floor plan drawing, encircling an area in order to identify the building boundary between the exterior and the interior. After the boundary has been defined, designers then use simple elements such as lines or bubbles to further partition the entire floor into individual rooms in order to locate the interior spaces and to match the requirement of building program 2. By assembling those basic elements lines and bubbles, architects 1 In the first design studio of the three-year Master of Architecture program in the University of Washington, students are asked to explore the idea of the boundary between the artificial and natural world by photographing for their first assignment. Students are allowed to choose any subject and arrange photos as a collage in order to present their thoughts about the boundary. 2 According to a video transcript of a participant s design session in a design drawing experiment, the participant started to arrange the spatial layout by enclosing the site boundary, which actually means the exterior boundary of the building. The participant then drew lines to partition the entire building into several individual rooms according to the program requirement (Ellen Do, 1999)

3 compose the drawings and explore the ideas of spatial layouts. In addition, designers may identify different spaces in terms of their functions by labeling their functions with different symbols such as letters or abstract drawings of furniture. Figure 3.1 shows that lines and bubbles are commonly used in a sketch floor plan for designers arranging the spatial configuration. 32 Figure 3.1, lines and bubbles are commonly used in a sketch floor plan for designers arranging the spatial configuration. Source: Ellen Do, 1998 Freehand floor-plan drawings can be conceived as a kind of flexible representation of designer s thoughts about design. Those floor-plan drawings abstractly show the alternatives of relationships among architectural spaces without specifying their detail structure. In a floor-plan drawing, designers use a line to represent a wall and use a bubble to represent an individual space and further assemble lines and bubbles to create a floor plan that actually represents a building. Furthermore, the use of simple lines or geometric polygons in the early conceptual drawings can be seen as a key clue for creating a 3-D modeling tool used in the early stage of designing. Because designers draw lines and bubbles to explore spatial configurations, a modeling tool should be able to recognize those lines and bubbles and generate a model of the space that the designer s drawing represents. Figure 3.2 shows how a computer modeling tool converts a designer s freehand drawings into a 3-D model

4 by recognizing and translating drawn elements (lines and bubbles) into architectural components (walls). 33 Figure 3.2, A computer modeling tool converts a designer s freehand drawings into a 3-D model by recognizing and translating drawn elements as architectural components 3.3. Use of Symbols in Freehand Drawings Designers usually use different drawing conventions in their drawings in order to identify different design concerns. According to several empirical studies, conducted by Ellen Do, about the use of drawing conventions in early conceptual freehand drawings, designers do use different symbols in a conventional way in their drawings when thinking about different concerns (Figure 3.3). For example, designers draw furniture with simple shapes in plan drawings when exploring the issue of functionality of space. Lines with arrows usually are used to indicate either movement of circulation in plan or sunlight directions in section (Figure 3.4). Figure 3.3, Conventional symbols for different architectural concepts in freehand drawings. Source: Ellen Do, 1998

5 34 Figures 3.4, Lines with arrows usually are used to indicate either (a) sunlight directions in section or (b) movements of circulation in plan. Source: Ellen Do, 1998 In addition, designers also use text labels to identify architectural concepts in terms of functions. Typically, in order to identify the proposed function of a certain space, labels are written inside a containing shape (usually ovals or rectangles), which is referred to an enclosed space. Figure 3.5 shows how a designer has labeled certain spaces with text to identify their functional uses. Figures 3.5, Labels of functional space are written inside a containing shape. Source: Ellen Do, 1998 Drawing conventions also can be found in Louis Kahn and Le Corbusier s freehand drawings. In Figure 3.6 (a), several drawing symbols can be identified in Kahn's sketches, such as a piano, several rectangular blocks representing furniture, texts indicating architectural functions (including single letter, such as K, L, S, and words, "guest room", "laundry"), two circular bubbles representing trees. In Le Corbusier's drawings (Figure 3.6 (b)), text labels also can be identified. In addition, short curve line segments with

6 arrows representing the direction of door swing and symbols indicating stairs also can be found. 35 Figure 3.6, Drawing conventions can be found in Kahn and Corbusier's drawings. (a) Kahn's sketches of a house project, (b) Corbusier's freehand sketches. Source: Brooks, 1991 & Scully, 1987

7 Space is enclosed by defining elements such as walls and columns 3. Different spaces have different spatial configurations of elements. When arranging spatial layouts through making drawings, designers may also start to explore the alternatives of spatial configurations of architectural elements. When a designer labels each space with a symbol, not only does he identify the function of the space but also he reminds himself of the proposed configuration of architectural elements. For example, a designer labels a sketch bubble with text BR to indicate the function of a bedroom in a drawing. He may also keep a conceptual scheme of the spatial configuration of elements in his mind. The label can be conceived as a representation of the spatial configuration in designer s mind. Figure 3.7 shows that designers may label different types of spaces with different text in order to identify different functions and spatial configurations. By applying symbols into drawings, designers assign meanings, give characteristics, and imply spatial configurations to every space. 36 Figure 3.7, By categorizing spaces according to their functions, designers can label different spaces with different texts to indicate different configuration The fact that using symbols is a way people compose 2-D drawings in order to explore different design concepts is one of the general notions for the thesis. However, this thesis mainly focuses on designers labeling interior spaces in floor-plan drawings with symbols 3 A space is defined by an enclosure that is actually a set of elements with a kind of configuration. Generally, elements can be categorized into two main categories: horizontal elements and vertical elements (as Ching suggests in his book Architecture: Form, Space & Order). The horizontal elements in architecture are mainly planar, including the base plane and the overhead plane. The level change of both the base and overhead plane and the distance change between two planes both affect the characteristics of a space. On the other hand, the vertical elements, which generally include linear elements (columns) and planar elements (walls), are more active in people s visual field than horizontal planes, because vertical elements form the vertical boundaries of a space. The vertical elements are instrumental in defining a volume of space and providing a strong sense of enclosure for those within it. (Ching, F.1979)

8 (usually text) in order to identify their functions and also indicate proposed spatial configurations of architectural elements. Furthermore, those labels in a sketch floor plan can make it easier to generate 3-D models. As discussed above, designers may label spaces with symbols to imply spatial configurations. Therefore, instead of drawing architectural elements to generate spaces, designers can simply use labels in a sketch floor plan and train the computer modeling program to recognize the spatial configurations that those labels represent, and then have the program create the appropriate architectural elements to enclose the space. Figure 3.8 shows a modeling tool creating a 3-D model according to the spatial configuration that the drawing symbol represents. 37 Figure 3.8, A modeling tool creates a 3-D model according to the spatial configuration that the drawing symbol represents The computational implementation of the SpaceMaker is mainly based on the studies of the fundamental characteristics of freehand drawings and the role of drawing symbols in freehand sketches described in this chapter. The SpaceMaker makes space models by recognizing the fundamental features and symbols in designer's freehand sketches. The following chapter will address its implementation.