傳統的二維地理資訊，無法貼切描述真實世界概況，加入資料空間屬性，以三維虛擬空間展示資訊，可增加資訊管理的效率並提升使用資料的便利度。利用電腦構建相仿於真實世界之虛擬空間，讓使用者感受置身於實境，進行動態瀏覽與查詢，已成為時下熱門的研究主題之一。 當下已有許多研究參與三維房屋模型建置過程，其技術已達成熟階段。下個階段，主要為紋理的產生與敷貼。大部分現有商業軟體支援面狀紋理敷貼主要是以多邊形的方式快速將紋理敷貼至對應的模型面，為重建三維房屋模型之方便工具。完整的紋理影像往往無法從單張影像中取得，故本研究利用多張影像進行鑲嵌，得到完整的紋理影像。首先利用人工圈選興趣區域 (Area of Interest, AOI)，使遮蔽區紋理不進入鑲嵌程序，接著選取足量的影像共軛點，建立工作座標系，並找出影像重疊區。透過邊界條件與權重條件產生數學調校模式，調整影像重疊區光影效應，產生幾何性良好與光影連續之鑲嵌影像。透過線性與參數式的轉換，將紋理影像敷貼到正確的空間座標上，最後在三維虛擬空間中展示敷貼成果。 Three dimensional geo-information is a fast developing topic in remote sensing and Geographic Information Systems. Using the technology of remote sensing, 3D building models could be constructed to resemble real buildings. However, currently, most building models do not have sufficient texture characteristics. The lack of texture not only makes 3D building models less realistic, it also fails to provide needed information, especially for complex applications such as cyber city implementation. The purpose of this study was to produce accurate texture mapping on building models. The textures were generated from mosaic of digital pictures taken from different angles and distances. Because of different picture-taking conditions, individual pictures might have different brightness, shadings, and other properties. All of them needed to be addressed before the mosaiced pictures can be mapped onto building models. This study developed a procedure to integrate digital pictures and correctly mapped them to corresponding objects in building models. The procedure first excluded shadows in the pictures. Then, overlapped regions were identified using tie points to develop mathematical relationship of the target objects across pictures. The developed mathematical models were then used to merge the pictures to generate a smooth and seamless image of the target object. Finally, the mosaic images were mapped to correct building facets (walls) using linear transformation and parametric transformation. The resultant building models should have a more accurate texture and improve the reality and practicality of cyber city implementation.
