具檢驗手繪兩點透視立方體功能之電腦輔助教學系統研發

Developing a Software System to Examine Cubes Drawn Via Two-Point Perspective Approach

產品設計程序之前期階段中，手繪圖稿是許多設計師發展構想之主要媒介。目前表現技法教育多未針對建構空間概念之基本單位－－正立方體－－的繪製加強訓練，易使手繪透視草圖因比例失調而無法正確符合視覺經驗，進而減緩構想發展速度；此外，尺寸概念薄弱所引發之相關問題，亦常在透視圖形轉換為工程尺寸描述之過程中，出現偏離原設計想像的情況。為改善此些問題，本研究以正立方體為練習標的、傳統紙筆配合數位繪圖板為輸入介面，根據兩點透視足點法發展逆向圖法，建構一個可供學習者初階手繪概念練習與進階自我修正的電腦輔助教學系統，即時針對每一手繪立方體推算正確圖形供比對修正，可提升學習成效並增加學習資源。經查，無相類似功能之系統，具首創性；教學實驗指出，系統之使用性良好，具實用性；受測者於立方體草圖繪製上之正確率提升近二成，具有效性。

Freehand sketch is a central medium employed by designers during early stages of product design. Due to the lack of sketching practices on the fundamental spatial conception construction unit - cube, freehand sketches were usually unproportionally drawn which do not match visual experience and slow down the concept development process. Furthermore, weak spatial conception leads to appearance design deviation when converting perspective drawings into orthographic drawings. To ease this problem, a computer-aided 2-point perspective cube sketching software is developed based on a reversed 2-point station-point approach proposed by the authors. It can be used to analyze the user's drawings and provide correction instruction feedbacks, serving as the first system with these functions and an interactive learning tool for novices in product design to enhance learning effect. Its usability was validated through a series of experiments done in real classroom setting. As a result, an average of 19.5% increase in drawing accuracy was shown in test subjects trained with the proposed system.