Bilgisayar Ortamında Tasarlanmış Planlar İçin Otomatik Olarak Cephe Üretilmesi

Abstract

AutoCAD ortamında çizilmiş bir bina planının ilk eskiz cephelerinin otomatik olarak çizdirilmesi hedeflenmektedir. AutoCAD üzerinde çalışabilen, AutoLİSP programalama dili kullanılarak yazılan, otomatik cephe çizimine yardımcı olabilecek bir program geliştirilmektedir. 1. Bölümde çalışmanın amaçları açıklandıktan sonra, konunun önemi ve BDT'nin (Bilgisayar Destekli Tasarım) kullanımı ile yapılabilecek işlemlerden kısaca sözedilmektedir. Bilgisayar kullanımının getireceği kolaylıklarda kısaca ele alınmıştır. Ayrıca program mantığı hakkında kısa bir açıklama yapılmaktadır. 2. Bölümde Bilgisayarın yapısı hakkında kısa bilgiler verilerek, Teknolojideki gelişmenin Bilgisayar Destekli Mimari tasarım üzerindeki etkileri anlatılmaya çalışılmıştır. 3. Bölümde Literatürde bilgisayarla bina cephelerinin tasarımdaki çalışmalar taranmış ve konu ile ilgili bulgular ve kullanılan teknikler anlatılmaya çalışılmıştır. 4. Bölümde programın yazılış sırasındaki kabuller, metodu ile ilgili bilgiler gerekli ve açıklayıcı olacak şekiller kullanılarak anlatılmaya çalışılmıştır. Burada Akış Diyagramı yardımı ile programın genel mantığı hakkında genel bir fikir verilmiştir. Programın kullanımı için gerekebilecek kullanım kılavuzu ve programın kullanımı için gerekli önerilerden bahsedilmiştir. Sonuçlar bölümünde ise programın kime yönelik olduğu ve geliştirilebilme yönleri konusunda bilgi verilmektedir.

The aim of this work is to attain automatic drawing of preliminary sketches of facades from a building plan drawn using AutoCAD. This work has been performed to satisfy the need for automatically drawing for the facades of a plan. The basic goal is the minimising of the time and labor that are required by normal methods for creating the facades of any plan drawn using AutoCAD. The starting point was the idea that the user should not have to specify again the window and door places and the external contours of the building for drawing a facade after specifying these once in the plan. The facades created by the program will be the first preliminary sketches and the real facade will be formed by the interventions of the user to these preliminary sketches. AutoLISP has been chosen as the programming language. AutoLISP is a language formed by adding the AutoCAD commands to LISP, which is a list oriented language. Application programs running on AutoCAD can be written using this language, and these run free of problems. This work is an application program which can serve as an example to such applications. Some of the main reasons for choosing AutoLISP as the programming language are: -The program will produce facades in AutoCAD for plans created also with AutoCAD, -AutoCAD commands can be called from this language, -Dialogue boxes can be employed from within AutoLISP. Also, another facility of AutoCAD R12, DCL (Programmable dialogue boxes) has been employed. Using DCL was beneficial because data entry is very easy and correct, and the values assigned to variables are displayed on the screen. Through this facility, the user may make all modifications until the last moment and change the values assigned to the variables in anyway he/she desires. This operation is very important because the user sees the values entered simultaneously in the screen and can modify these up to the last moment. VI All data required by the program during the drawing is obtained from the plan, and during the drawing of the facade, from the user. The data obtained from the plan are the outer wall levels and door and window places. The user is prompted to enter other values that may be required during the drawing of the facade. Some of these are as below: - Text to be displayed below the facade belonging to the facade being drawn. - Which project does the facade belong to - The direction of the facade - How the text will be written - The text style to be used - The height of the text - The angle of the text - The floor name of the facade being drawn - Ground floor - Normal story -Roof - Whether there will be a roof over the last floor - Scale to determine the level of detail of the drawing: -1/50 - 1/100 - 1/200 - Number of stories (1 if the ground floor to be drawn) - Height of the story - Height of the parapet - Height of the window - If a normal floor is being drawn, the bottom elevation of the 1st Normal floor - The direction of the facade to be drawn -North - South -East -West - Data related to the windows in the facade - The thickness of window frame - The number of vertical window sections - The situation of the vertical sections in the windows (equal or differing intervals) - If applicable, opening leafs - Data relating to the roof - Roof parapet height (the default value is equalized to the window parapet height) VII - Roof eaves width - Bottom elevation of the roof parapet (not required if the roof is to be drawn with the floors) After the above values are collected from the user via dialogue boxes, the drawing for the specified direction will be displayed on the screen. As will be mentioned in subsequent literature review sections of this work, there are some techniques developed to allow the computer to perceive the drawn objects by recognition and to perform the desired operations using them. These techniques are: - Edge Detection - Contour Following - Form Recognition The method used in this work is similar to the "Contour Following" technique. But, the method used is not exactly the same. According to the new technique developed, objects which are walls are determined from the plan of the building. The obtained wall objects are screened through a second process leaving the wall objects belonging to the desired direction. In order to determine the outer contours, the outmost edges of the obtained wall objects were used. The middle points of the same object besides the two edges are used for the door and window places. The facade is created by combining window door levels extracted from the plan with all the data obtained from the user concerning the front. Hence, the chapters, subject titles and contents reviewed in this work is as below: In the 1st Chapter, a short comparison between the traditional methods and usage of computers is made and the possibilities the computer offers to the user during the production of a facade are discussed. Besides this some summary information is provided for the jobs to be performed with this work and the facilities it will offer the designer. The aim here is to further the automation of the drawing of facades which are currently drawn as a normal plan, and to provide a way for easily drawing the automatic facade of a plan already drawn and its alternatives and to satisfy the need for automatic drawing of facades. Even though a complete front cannot be drawn exactly in the manner contemplated, a VIII partial drawing is made automatically with the parametric values being entered by the user and others being extracted from the plan. In the 2nd Chapter, some information about the computer system is furnished. To achieve this the structure of the computer system was examined and the fundamental change in architectural applications due to the daily usage of CAD techniques were explained. The fact that many factors play a role in this operation was explained. Then, the subject of components of a computer system was considered and information about the components was supplied. The computers were defined as electronic tools that are able to store data in their internal memory and to use command series from these stored data known as programs to perform these operations. Some short explanations about some of the components of a computer system; hardware, central processor, data and software; were included. A typical computer hardware was illustrated and short explanations about the computer hardware were provided. It was explained that the whole system is controlled by a CPU directed by an arithmetical and logical unit. It was stated that any device which converts any type of data to electric signals; a punch card reader, a keyboard, a TV camera, a microphone or sensor or any other device; can be used as a computer input device and that programs are a series of commands written in a computer language. Simple and complicated programs were illustrated by figures. Finally in this chapter, the effect of technological development on the possibility of Computer Aided Architectural Design was discussed. In the 3rd Chapter, information about the existing literature concerning the design of building facades with a computer was provided and computer graphics in the definition of building facades were considered. It was stated that the role of computer graphics in CAD is a controversial subject, and that some people view computer graphics and CAD to be synonymous, others argue that advanced and encompassing research should be undertaken before computer graphics can be used for designing. It was explained that others claim even the simplest of computer graphics results in large savings in design costs. Also the subjects of syntax, object recognition, elevation studies, picture libraries and three dimensional graphics were reviewed under short headings. Some information was provided concerning to the subject of descriptive design under the heading of data-based building elevation formation efforts. Also the benefits of shape recognition were discussed, and edge detection, contour following and form recognition, which are some of these studies, were explained. IX In the 4th Chapter, the methodology, the user manual of the program and the flow charts were explained. The methodology section points out the aim of the work and the operations to be performed. Where and how the program obtains the data was explained. The operations to be performed with the running of the program were explained using figures and dialogue boxes. The data required for the program to run and the default values that will be used in the absence of these were listed step by step. After that, the subroutines used in the program were listed in the order they were used in the program. In the section explaining the user manual of the program, the steps necessary to load the program from AutoCAD and the operations required to run the program were specified. The usage of each variable in the dialogue box was explained, and the data type to be entered to ensure correct operation of these were pointed out. In the results chapter it was stated that the program will minimise the time and effort to be expanded by the designer for drawing during the preliminary sketch. Consequently, it is possible for the designer to utilise the time required for drawing instead for designing, to develop more alternative facades. Also, in this section it was stated that the structure of the program allows expansion, and additions would improve the program. It was explained that with the program all windows belonging to each area can be drawn in separate and differing forms, dimensions and shapes. The program can be used as an editor to make the necessary modifications to both the general contours of the facade and the window modules. It was explained that the program could be made to draw a roof in a facade using a roof plan of a project. In the appendices the source code of the program and the text of the dialogue box used in the program were included.