網路式虛擬實境建立系統於二維圖集再利用之初步研究

Abstract

本研究主要目的乃在於建立一「網路式自動化虛擬實境建構系統(Web-based Automatic 2D-to-VR system, AutoVR)」，再利用建築營建工程中已繪製好的工程設計圖集，將這類平面二維的圖集自動化地解讀與辨識成為虛擬實境的電腦3D模型，以供建築專案設計團隊中不同領域的人員能夠輕易地藉由3D虛擬實境專案進行溝通與協調。 由於傳統二維的電腦輔助繪圖系統已無法滿足現今建築營建領域中複雜結構的需求，例如：二維圖集資料交換困難、難以利用分散式圖檔資訊進行溝通等等，許多新一代物件式的3D電腦繪圖系統便應運而生。然而，建立3D模型所花費的時間與資源以及所需要的技術往往為製作二維圖集的數倍，再加上現今的3D電腦繪圖軟體並不能再次利用二維圖集來建立新的模型，而必須重新建立其3D模型的資料庫，如此一來，建築營建公司或設計團隊所付出的成本除了軟體及技術費用之外，還有最珍貴的圖集資源。 因此，若二維圖集與3D模型之間不能建立起一個再利用的關聯，則設計團隊就可能會採取保守的態度，繼續使用二維製圖方式，使得資料難以交換、團隊中不同領域人員之間難以溝通的問題依舊存在。 針對上述之問題，本研究以PHP（PHP Hypertext Preprocessor）互動式網頁程式，利用3-Tier架構建立一網路式的虛擬實境建立系統，使用者上傳其結構工程的鋼結構設計圖集至系統後，系統會利用電腦圖層命名規範以及電腦製圖規範，將設計圖集的圖檔資料分類與解析並存入資料庫內，再利用PHP自動建立一VRML（Virtual Reality Modeling Language）架構的互動式建築虛擬實境專案。

The main objective of this research is to develop a “Web-based Automatic 2D-to-VR system,” denominated AutoVR. The AutoVR system can extract and analyze the information in two dimensional drawings of construction drawing sets. By reusing the construction drawings, the AutoVR system can automatically create a virtual reality (VR) construction project. This VR project provides a convenient environment for different fields of people in the design group and helps to communicate their thoughts and ideas about the project easily. Since there are some defects in the traditional 2D drawings while describing the sophisticated construction project, for example, difficult to exchange product information or to communicate by using 2D drawing set, many 3-D object-oriented computer-aided drawing systems are developed. However, there are still some serious problems in most 3-D drawing systems: They can’t reuse the information in traditional 2D drawings; establishing a 3D construction project usually takes more than twice as long to designer as it takes to draw a comparable amount of data using a traditional CAD system; the prices of using 3-D CAD system are not only the cost of software and technique but also the invaluable resources of construction drawing sets. Therefore, if the relation between 2D drawings and 3-D models can’t be established, the companies and design groups may keep using the traditional 2D CAD systems to build up their construction project. The product information will still be hard to exchange and the problems of communicating between different fields of people in design group remain unsolved. To avoid the aforementioned problems, this research develops the AutoVR system by PHP (PHP Hypertext Preprocessor), MySQL database and 3-Tier architecture. After the user uploading his construction drawing sets to the system, the system will analyze the drawings and extract the information which are organized by CAD drawings standards. Then the system will automatically store the information into the MySQL database and create a VR construction project in VRML (Virtual Reality Modeling Language) by PHP. The models in the created VR environment are object-liked and the environment is interactive with users.