ビジュアルプログラミングによる斗栱部の部品・部位表現に関する研究

伝統木造構法のコンピュータ言語による記述

抄録

 Visual programming has quickly become widely used tool for algorithmic design in the past several years. Because the contents of visual programming are easy to understand and intuitive, it is also leveraged for describing design process.
 On the other hand, the authors studied 3D based knowledge representation for traditional wooden architecture or wooden skeleton structures houses. In previous studies, detailed 3D models could be created using parametric part classes which were defined with text programming; however, contents in the part classes were complicated and unsuitable for sharing as knowledge, challenging the requirement that the part classes and parts structure should be represented clearly.
 In this paper, the authors attempt the executable graphical representation of building system for traditional tokyo-bu by using visual programming. Through the development of a visual programming system, multiple ways of representation are considered. Representation methods with visual programming are studied based on two themes: part class including design method and parts structure.
 In the study of design method, eight types of components are defined: parameter, variable, vertex, segment, plane, solid, process and func. The components are similar to a craftsman's work. Process components include sawing and chiseling by subtracting solids from a solid. Func components imply drawing practices such as drawing perpendicular bisector or solving intersection of two lines. By using the components and directed connectors which have an entry sequence, the design method for masu and hijiki are descripted graphically. The design method has some inputs for parametric forming. To represent systematized proportionality relations which are typified as kiwari, a base of part class comprises two kinds of information, design method, and its inputs, which are described with parameters and variables. By this composition, part classes for masu, which are based some traditional drafting rules, are represented as organized diagrams. A base of part classes for hijiki, which are based on traditional rules called kansatsu, is also represented.
 Parts structure based on part classes in the preceding section results in a complex diagram. Many components and connecters are employed for describing the location of each part. It is shown that mistakable redundant description, such as a redefinition of a variable. To solve this issue, the authors incorporate a technique called scene graph. Scene graph is a technique for creating a tree-structured 3D scene. The technique establishes a Parent-child relation, which makes a tree-structure containing relative attitudes and the locations of each part that are calculated by pursuing relations. Relative attitudes to connectible parts type are added to the description of the part classes. Finally, the part class is represented with three kinds of information, design method, its inputs, and contestability. The behavior of a part will be represented by the part class. With these part classes, part structures of tokyo-bu are represented clearly. The representation shows a formal order for dimensions of parts. Connections of each part also illustrate its assembly.
 Processing systems for visual programming are also shown. It makes the graphical representation executable. The system consists of a visual programming editor, database, for managing components and connectors in editor, and interpreter to convert visual programming into executable scripts.
 The authors conclude that the part class, including the design method, and the parts structure is clearly represented through visual programming. Executable graphical description with visual programming could be used for knowledge representation for building system.