4D(Four-dimensional)models ,將工程量體(3D Model)與工程排程(Construction schedule)相結合,以視覺化(Visualization)方式呈現並模擬(Simulate)工程的進行。運用在實際的工程管理上,可以提早發現各種時間與空間的衝突問題並預先解決。亦可以作為分析的工具,找出工程資源、場址運用及工安設施配置的最佳規劃,進而達到整體工程最安全、最經濟、最快速的管理目的。 本研究發展一套4D模擬系統雛型,名為「A4D模擬系統」,利用X3D產生的虛擬實境展示來模擬鋼結構工程現場的3D models,並利用了X3D中的SAI(Scene Access Interface)介面操控虛擬實境場景,及透過這個介面與外部資料溝通,達成工程量體與工程排程相結合的4D模擬目的。 本研究亦發展出一套4D models檔案格式,名為「A4D」,用來作為A4D模擬系統的資料格式。A4D利用XML(eXtensible Markup Language)語言結合X3D(虛擬實境語言)格式及Microsoft Project(商用排程管理軟體)格式,在不破壞各套裝軟體原始檔案格式的前提下,達到兼具相容性及擴充性的目的。
4D (Four-Dimensional) simulation combine 3D (Three-Dimensional) models and building construction schedules to visually simulate the construction process of building. Through 4D simulation in engineering project management, the conflicts of space and schedule can be detected in advance. 4D simulation could also serve as an analytical tool, helping project managers to optimize project resource utilization, site logistics and safety plans. In this thesis, we have developed a prototype 4D simulation system, named the A4D system, for steel structure construction. The system presents 3D models of steel structures in the Virtual Reality environment using the X3D (eXtensible 3D) standard. In this X3D-based Virtual Reality, 3D objects communicate with outside temporal data through SAI (Scene Access Interface) to archive the integration of 3D models and construction schedules. In addition, a data file format, called A4D, that combined the X3D format and the Microsoft Project XML file format, has been developed in this work promote the sharing and exchange of 4D simulation information.