摘要
In recent years, development of computer graphics is incredibly fast from 2D graph to high quality of 3D environment. Applications of industrial design, animation and computer games are often seen to make progress; the analyzing of cost efficiency and quality standard are priorities of developing. To research for new methods of quickly displaying large numbers of data set, and massive scientific simulation is the trend of unceasing development. In the procedure of industrial design, it is almost impossible for one person from initial idea conception to 3D realization. Designers sketch for conceiving concept and digital modelers have to operate CAD software to reconstruct 3D shapes of sketch. We could quickly sketch for idea conception without considering the precision. But it takes us lots of time to get familiar with massive commands and relevant knowledge of background. So we propose a real-time system of combining advantages of sketching and user interface for novice users which could intuitively do idea conception to reconstruct 3D objects as their wish at once. First of all, users need use mouse or optical pen to input the plane information to provide the reference of 2D to 3D coordinate transformation. In the 3D coordination, sketch is processing in 2D virtual canvas and interactively calculating with system in real-time. Our system brings up a new idea of differential sketch sequence for displaying crabwise segment property. Because of providing the environment with less restriction, it could show variety of composition of segments. Surface boundary tracing algorithm is used for drafted segments to extract surface boundaries successfully, and then reconstructing for 3D object. The experimental results are separated into two parts; stroke and surface performance. The stroke part could compose of complex segments for idea conception, and the surface part is also successfully reconstructing 3D objects designed by users to perform real 3D reception.
並列摘要
近十年來，計算機圖學(Computer Graphics)發展地異常迅速，從二維(2D)圖形進步到複雜的高品質的三維(3D)環境。而較常見則為工業設計以及動畫電玩類的應用發展，其發展之考量重點為成本效應分析與品質追求。研究新的方法，以快速地顯示大量數據集合和大規模科學仿真結果是不間斷的發展趨勢。工業設計流程中，從初期概念到三維實現幾乎不可為一人能力所涵蓋。設計師利用徒手草繪來傳達觀念，數位模型師必須將其手繪利用CAD軟體將其還原重建。而概念發想過程其實不需要考量精確度，利用手繪即可以快速實現。但是學習CAD軟體必須花費大量時間去熟悉複雜的指令以及相關的背景知識。 本論文提出一個結合了手繪以及CAD中互動介面的優點的即時系統，讓非專業的使用者可以直觀的做概念的發想，進而快速的重建出所欲表達之三維形體。 使用者首先利用滑鼠 / 光學筆輸入平面座標資訊，提供後續二維與三維座標轉換的參考資訊依據。在三維座標環境中，手繪動作於二維虛擬畫布中執行且與系統即時交互計算，進而取得所欲表達之筆觸線段資訊。本系統亦提出新的概念，利用繪畫順序差異表現出橫向線段的延伸特性。因為提供較不受限的使用環境，故可以表現出較為多樣性的線段組合。而繪畫線段經由曲面邊界追蹤演算法(Surface Boundary Tracing Algorithm)，可以成功的分類出面向邊界資訊，進而得以重建還原三維形體。 實驗結果分兩部分陳述;為線段與曲面呈現。線段部分得以複雜線段的組合表現出使用者的概念性思維。曲面部份亦成功重建出使用者所設計的三維形體，表現出真實的立體感受。