A GENERATIVE MODEL FOR OBJECT DESIGN FROM LETTERS IN PLAYGROUND

Elif Günay

Istanbul Technical University, Institute of Science & Technology,

Architectural Design Computing Graduate Program, Istanbul, Turkey

Prof. Dr. Gülen ÇAGDAŞ Coordinator of Architectural Computing Master Program, Institute of Informatics, Istanbul Technical University, Istanbul, Turkey. e-mail:cagdas@itu.edu.tr

Abstract

In this paper, structure of a grammar model for design of a children’s playground, involving playground objects evolved from letters of alphabet, is introduced. In the project the main idea is to think the letters as the main shapes for the shape grammar model. This computer aided design model makes use of boxes and arcs only, in accordance with the three main rules which are limiting the number of shapes that can be used at most, the number of shapes that can be used at least and how the shapes should be oriented. Following the main three rules and making use of a custom script with AutoDesk 3D Studio Max version 9.0, twelve different template shapes derived from the shapes of letters, are generated. Before starting the study of the design process for the project, two major points taken into account regarding the selection of an appropriate alphabet to be employed in the design, are explained. First task executed for the selection process has been the search for alphabets that would be suitable for the design, i.e., alphabets consisting of letters which are of elastic and soft figures. After the selection of a group of letters, an analysis was carried out in order to divide each of them into their basic geometrical constituents. Second part of the preliminary work, was the development of two different custom scripts to be used for the generation of each shape and the Guide User Interface (GUI). The first script generates shapes in sequence, without any modification of the original shapes, by letting the user to define the number of objects in a sequence and the distance between the objects. The second script, on the other hand, generates shapes with some modifications by using ordinary commands like taper, bend, squeeze and scale. During the creation of this shape grammar model, needs of a children playground were taken into consideration, bearing in mind that playfulness is an important feature of children’s life. This generative model expresses how it can be possible to transfer the virtual world in a child’s mind into a reality through basic rules in computer programming.

1. Introduction

After the advance of computer programming languages, virtual worlds started to interfere in variety of areas, such as generative arts. Not only computer programmers but also designers are capable of developing scripts to create imaginable environments by making use of different programs that working on 2D and 3D. In recent years, people have a desire to see technological products everywhere, especially children who are started to become central objects in the market of industrial products. ‘As our design partners in developing new technologies, children can offer bluntly honest views of their world. They have their own likes, dislikes, and needs that are not the same as adults’ [1]. During the design process designers should be in collaboration with children in order to understand what playfulness means in their outdoor and indoor activities. Playfulness is the capacity to draw satisfaction from the immediate intellectual development of a topic, irrespective of any ulterior motive. [2] Playfulness is a source of amusement for children. All children, no matter where and in which conditions they live, are capable of creating a play area for themselves and during the play they can adopt a different identity.

What is the significance of play and playground and what are its effects on children? Researches shows that play have an important effect on a child’s development. For this reason, international organizations like UNICEF and IPA are also dealing with rights of play and playgrounds. The basic statement of both organization regarding the children’s play and playgrounds, is that children have the right to play and these rights must be guarantied by the adults.

Children should be provided with proper places where each element of the playground is designed and serviced in a different way to create sense of a space and to alert perception and motor improvement. Children must be in command of different concepts, such as in, on, under, outside, left, right, far, near, color and rapid of designs, to develop a sense of space. A playground enables the child to cognize, shapes, sizes, numbers, and relationships between pieces. In other words, playground is an educational environment which helps improvement of social, physical, sensual and cognitive behaviors of children. If children have this opportunity, they become more creative, and they can find more flexible solutions to problems, and also they can develop better and healthier relationships with other children.

To create design playground objects, shape grammar methods were examined and it was decided to use some alphabets resembling each other and consisting of not only letters but also symbols. As a consequence of a thorough research, alphabets of Russian, Greek and Sanskrit were chosen. One of the most important criteria in the choice of letters has been their possession of at least one common shape and their capability of being transformed into other shapes which are possessing elastic or soft forms. All letters which were selected to generate shapes are shown below. (Figure 1)

Ψ Ω β ф ю P O

Figure 1: Letters are chosen according to three different alphabets like Russian, Greek and Sanskrit.

Following the forms of those seven main letters, twelve shapes were generated. One of the letters was taken directly to generate forms for playground’s element as an initial shape, i.e., “Ψ” the other eleven are changed according to the base shapes and initial shapes.

2. Generating Shapes

Stiney's formalization of the shape grammar provides a semantic model with a compressed representation of architectural form (Stiney 1978 and 80). The discipline of space syntax, developed by Hillier provides analysis of spatial configurations with empirical data that could be developed into fitness criteria (Hillier et al., 1984, 93 and 96). [3] In this shape grammar model, principal letter at the beginning of the design process was kept fixed and an analysis of each principal letter to its sub-components was carried out at the beginning of the design. Below, it is illustrated how they are divided into basic constituting figures such as, box and line in two dimensional space, and the composition of these two basic figures in three dimensional space in such a way that the composition obeys three main rules which are,

1. All shapes are built by using at least an arc and a box.

2. All shapes may contain a maximum of two arcs and two boxes.

3. All boxes must be placed in the middle of the arcs or at the edge of the arcs.

Following these three main rules, four different variations of composition were created.(Figure 2)

Ψ Ω β ф ю P O

2D …………………….

3D………………………

Figure 2; division of letters to the basic constituting figures and development of four different compositions for shapes.

2.1. Generating Sub-Shapes with using a custom script 1

Firstly, the initial letter was choosen and a custom script to generate the pieces of initial

Shape, i .e. box and arc, and guide user interface (GUI) was developed by using 3D Studio Max version 9.0. According to three main rules which is shown in Figure 2, script 1 produces both twelve shapes and GUI. During the generation phase, there are two important steps: one of them, is to determine the size of the shapes that will be created; the next step is to decide the position of the object and the way it is connected to the others. After creating the initial objects that were derived from those boxes and arcs; a capability of movement about x-axis, y-axis and z-axis, was ascribed to them. Making use of this movement capability and repeating of those objects, 12 different shapes were generated by using Script 1. The twelve different shape rules are listed in the following figure (Figure 3). User Guide Interface is a useful tool for generating shapes in the direction of user’s choices.(Figure 4).

Rule

Compenent - MODEL

Figure 3; is shown that generated 12 shapes. Figure 4; GUI is written as a custom script.

When a user chooses any rule on the GUI and clicks on “make” button the custom shapes are created automatically according to the initial shape of the rule in this shape grammar. The user can define the number of shapes and distance between each of them, also can change the color of shapes with using GUI. Every rule generates one shape and if user clicks on the “make” button more than once; shapes are created at the same position. When users choose some rules and click on them, cumulative alternatives can be created for designing elements of playgrounds (Figure 5).

Figure 4; indicates flowchart.

Figure 5; indicates flowchart.
2.1. a Generating Sub-Shapes 1(SS1)

All rules are generated in the same way. Units that are composing figures are be thought as consisting of two different components and the values for the movement and rotate are determined. The properties of the arc shape, for instance, are written in the script as follows:

Arc is named as “myArc” that is:"arc" radius:9 from:277 to:161 and extrude of arc is 5.0

and the properties of the box shape are written as follows;

Box is named as “myBox” that is height: 5.0 length: 1.055 width: 20.5.

For generating rule 1, one arc and one box are used and their position is determined in advance, to be at the origin. In the tables below, two main shapes of arc and box are considered as composed of two different components and the movement and rotation in and about each axis are shown;

Rule 1

Rotate

Move

Model

arc

box

x-ax.

y-ax.

x-ax.

y-ax.

z-ax.

-10

Table 1; explanation of the model rule 1

Rule 1 is thought to be the initial shape and represents the origin of the others. (Table 1)

Rule 2

Rotate

Move

Model

arc

box

x-ax.

y-ax.

x-ax.

y-ax.

z-ax.

-30

-5

xof-5

-5

Table 2; explanation of the model rule 2

Rule 2, is another version of Rule 1 (Table 2). It provides the production of playground elements with inclined angles, and as the angle changes it enables a variation in the activities such as jumping, passing through, swinging, etc. Taking the mirror of Rule 2, design of an element which allows swinging and passing through was realized (Figure 6). With the rotation of Rule 3 about y axis and mirroring that product a teeter totter is created (Figure 7).

Figure 6 Figure 7

Rule 3

Rotate

Move

Model

arc

box

x-ax.

y-ax.

x-ax.

y-ax.

z-ax.

-140

-5

xof-5

-5

Table 3; explanation of the model rule 3

Applying the mirror command to Rule 3 (Table 3) which was derived from Rule 1, it is possible to create an element that allows children to pass through a hole and to sit inside that

vacancy and also it is possible to create a tunnel by repeating the element (Figure 8). Besides, when it is rotated 180 degrees closed/semi closed units serving for the same function can be developed (Figure 9).

Figure 8 Figure 9

Rule 4

Rotate

Move

Model

arc

box

x-ax.

y-ax.

x-ax.

y-ax.

z-ax.

12.8

0.2

29.5

Table 4; explanation of the model rule 4

Rule 4, is already stable without any distortion (Table 4). When used as a single component, it provides a passage and partition. By applying the mirror command to Rule 4 about z axis and repeating that product a tunnel and a bridge are generated below and above respectively (Figure 10).

Figure 10

Rule 5

Rotate

Move

Model

arc

box

x-ax.

y-ax.

x-ax.

y-ax.

z-ax.

xof-9

-3

Table 5; explanation of the model rule 5

Rule 5, serves as a door when used alone (Table 5). By applying the mirror command to Rule 5 about y axis and repeating the product curved passages providing connection between elements (Figure 11).

Figure 11

Rule 6

Rotate

Move

Model

arc

box

x-ax.

y-ax.

x-ax.

y-ax.

z-ax.

140

xf-10 xf-10

-2.5

Table 6; explanation of the model rule 6

The most important feature of Rule 6, basically a semi-open shape, is its richness in providing alternatives by using two boxes and one arc (Table 6). Combining Rule 6 and Rule 5, rotating this combination 90 degrees about z axis and ultimately mirroring it about several axis, multifunctional elements, enabling such activities as climbing, jumping, passing over, are formed (Figure 12).

Figure 12

Rule 7

Rotate

Move

Model

arc

box

x-ax.

y-ax.

x-ax.

y-ax.

z-ax.

-0

-90

xf-10

Table 7; explanation of the model rule 7

Rule 7 is highly suitable to be combined with other rules (Table 7). Even the circle, which is one of the components of the whole body and standing on the ground, itself, is a very commodious playground element. When repeated, it allows running through itself. Combining Rule 7 and Rule 1 and repeating the same application, a playground element with holes that make it possible for children to run through, is obtained (Figure 13). When Rule 7 is combined with Rule 1, Rule 5 and Rule 8, elements for climbing, jumping, and passing through area created (Figure 14). Rule 7, is very helpful for the design of many elements for many different purposes.

Figure 13 Figure 14

Rule 8

Rotate

Move

Model

arc

box

x-ax.

y-ax.

x-ax.

y-ax.

z-ax.

-90

-9

xf-10

Table 8; explanation of the model rule 8

Rule 8 is a hollow unit itself and provides connection between a variety of elements. It generates many other alternatives with other rules.

Rule 9

Rotate

Move

Model

arc

box

x-ax.

y-ax.

x-ax.

y-ax.

z-ax.

180

-90

-10

Table 9; explanation of the model rule 9

Rule 9, shows the properties of a teeter totter (Table 9). However, when repeated in y and z axes, it forms a climbing element. Combination of Rule 9 with other rules; also, provide creation of a diversity of playground elements (Figure 15).

Figure 15

Rule 10

Rotate

Move

Model

arc

box

x-ax.

y-ax.

x-ax.

y-ax.

z-ax.

-14

-12

-18

Table 10; explanation of the model rule 10

Rule 10, provides a passage itself and generates spaces suitable for hiding.

Rule 11

Rotate

Move

Model

arc

box

x-ax.

y-ax.

x-ax.

y-ax.

z-ax.

270

-12

-18

Table 11; explanation of the model rule 11

Rule 11, is symmetrical to Rule 10 and provides bridge function (Table 11).

Rule 12

Rotate

Move

Model

arc

box

x-ax.

y-ax.

x-ax.

y-ax.

z-ax.

-12

xf-10

Table 12; explanation of the model rule 12

Rule 12, is designed as an element (Table 12) which provides several functions i.e., swinging, climbing, and supporting other elements, by making use of three shapes it possesses.

In Figure 16, some example shapes which were generated by using the first script are shown that can be used as objects in a playground and with the combinations of these rules it is possible to produce infinitely many .

Figure 16

2.1. Generating Sub-Shapes with using a custom script 2

All rules are generated in the same way. Script 2 is created by adding some transformation properties over he rules generated in Script 1. First script is taken without any change but some limitations are introduces for each rule. Here, already exist some limitations determined in advance- keeping in mind the needs for height, length, etc. - besides the features that are assigned by the computer randomly. 2nd script is a bit more advanced when compared with the 1st script, and can make use of transformations such as scale, squeeze, taper, etc.

R1 +

By the addition of Rule 1 in SS1, Twist modifier and Scale modifier are attached and some examples are generated (Figure 17). Some of them are used as semi- open spaces mixing the inner and outer space concepts, which are allowing to hide and slide together, also creating the idea of house-tent.

Figure 17

R2 +

By the addition of Rule 2 in SS1,Twist modifier and Scale modifier are attached and some examples are generated (Figure 18).These elements for playground design can be used as objects creating space-.... concept; tunnels can be built up by the repetition of the object, or may be used as a teeter totter or just as a seat.

Figure 18

R3 +

By the addition of Rule 3 in SS1, Twist modifier and Bend modifier are attached and some examples are generated (Figure 19). It is aimed to create objects for children to sit in different levels, climb up and while climbing to recognize and understand different geometric shapes and to manage with their relation.

Figure 19

R4 +

By the addition of Rule 4 in SS1, Twist modifier and Mirror modifier are attached and some examples are generated (Figure 20). This is again an object for climbing. When applied in y axis, a climbing element with a seating unit below is obtained. When applied in x axis only a seating unit is obtained.

Figure 20

R5 +

By the addition of Rule 5 in SS1, Stretch modifier and Mirror modifier are attached and some examples are generated (Figure 21). The designs obtained can be used as seating units for adults, and teeter totter and slide for children. There will be enough space left for hanging the swing.

Figure 20

Figure 21

R6+

By the addition of Rule 6 in SS1, Twist modifier and Mirror modifier are attached and some examples are generated (Figure 22). Seating units, slides and elements for hiding can be produced.

Figure 22

R7+

By the addition of Rule 7 in SS1, Stretch modifier, Ripple modifier and Taper modifier are attached and some examples are generated (Figure 23). It provides the production of a mini-amphi and a sand pool for children. At the same time, together with necessary additions, it is possible to create swing or cradle.

Figure 23

R8+

By the addition of Rule 8 in SS1, Stretch modifier and Ripple modifier are attached and some examples are generated (Figure 24). This is the rule for the creation of small lodges to be shared between children. It produces playground objects which favors adults to involve in children plays and provides elements for hanging.

Figure 24

R9+

By the addition of Rule 9 in SS1, Stretch modifier and Ripple modifier are attached and some examples are generated (Figure 25). It realizes objects that provide children to understand curved surfaces, enables them to swing and pass through and to sit in different elevations.

Figure 25

R10+

By the addition of Rule 1 in SS1, Twist modifier and Mirror modifier are attached and some examples are generated (Figure 26).An element which can be shared between children and adults. It serves as a seat for adults while providing passage for children. It can also be used as a teeter totter.

Figure 26

R11+

By the addition of Rule 11 in SS1,Stretch modifier, Ripple modifier and Twist modifier are attached and some examples are generated (Figure 27). It creates elements for climbing for children and creates seats for adults.

Figure 27

R12+

By the addition of Rule 12 in SS1, Stretch modifier and Mirror modifier are attached and some examples are generated (Figure 28). It creates elements which introduce organic forms to children while providing a tool to swing, climb and pass through all together.

Figure 28

3. Conclusion

One of the most important problems in the design of children’s playground elements is the fact that design process disregards the richness of the children’s world. However, children who are at the very center of technological development prefer different designs which excite them. Colors are also highly effective, as the design itself, in the perception of space for children. Since the knowledge obtained through observing and experiencing the environment are direct and without any dictating agent, are much more long-lasting.

In this project, the main idea is to create elements to satisfy many demands of children at the same time and the basic figures are chosen to be with soft edges in order to prevent the injuries.

Regardless of which script is chosen during design process, the end products, the custom shapes themselves, have common specifications. They can all be useful and suitable objects if used in a playground.

To conclude, the program, built up with a simple and user friendly GUI and two custom scripts, offers a creative and funny way for generating custom shapes which can be used as objects in a playground, by using just letters as the origin.

References

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