結論 - 三維電腦遊戲引擎之中國水墨風格人物白描技法模擬

本篇論文中，我們參考 Weng [35]的水墨模組，將毛筆模組的模擬機制應用於三維電腦遊戲引擎中，以電腦自動找出輪廓線與特徵線的方法，並綜合 Northup 等人[20,22]

提出的方法來繪製 ID 參考影像及處理場景中物體遮蔽問題，最後將可見的線段連接成 較長的線段，產生 Cardinal Spline 的毛筆移動軌跡，以呈現中國水墨人物白描技法的效 果，我們根據線條的變化與否分別模擬了五種的技法分別是：柳葉描、減筆描、竹葉描、

琴弦描、棗核描及最後的綜合模擬。我們知道畫家作畫時是隨性的寫意，然而在電腦繪圖的領域仍然受到許多的限制，比如說模型的精細度、傳統的繪圖機制限制以及需遵循規律的邏輯運算等等，都影響著結果。

在電腦繪圖上為使繪圖速度加快，通常會以降低場景的三角面總數量為考量因素之一，因為過多的三角面數量會增加 CPU 的計算量而降低繪圖的速度，尤其在 NPR 的繪圖上。在繪圖的速度上我們提出了繪圖狀態機，將傳統的繪圖機制拆成四個狀態分別是：全部繪製（已儲存影像）、先繪靜態部份（並儲存影像與深度值）再繪動畫物件、

回存靜態部份深度值再繪動畫物件與將儲存影像直接輸出至螢幕等四個狀態，系統再依照目前所處的狀態及其變化情形，以邏輯推算選擇下一個繪圖狀態來繪圖，用於提昇三維電腦遊戲引擎對輸出入裝置之反應速度，使畫面顯示與遊戲之操作更符合電腦遊戲軟體的需求。在 4.3 節中我們談到，在我們模擬水墨風格的例子上，對動態狀態機中的 C

狀態的繪圖速度幫助不大，但仍可藉由系統經常會到 D 狀態的優勢來提升系統的整體速度，使動態場景平均速率大於 11FPS、靜態場景平均速率大於 20FPS，以符合速度的要求。而我們提出的方法亦可應用於複雜的 PR 場景繪圖中。

未來我們可參考 Yeh[36]提出的方法將白描的模型內部加以上色，使之呈現更豐富的色彩效果，對碰撞部分加以處理使顯示完整的棋子移動過程，在速度方面找尋其他加速的方法譬如 LOD 與 Pre-process 的方法，使 NPR 水墨的效果更能夠應用於三維電腦遊戲引擎及虛擬實境中。

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