本篇論文提出創新的雙面2.5D圖畫，主要目標是在2.5D世界操縱傳統2D圖形時，以一些針對雙面卡通動畫物件的動畫特效處理技術，提供更多更豐富的視覺效果。將單面二維圖畫附加背面圖畫，就能創造出使用單面物件所無法達成的視覺效果。具體來說，我們輸入正反面形狀相同且文理貼圖豐富的圖畫，互相貼在各自的背面，然後藉由我們提供的特效技術包括滾動、扭轉、摺疊、形變，交互套用在雙面動畫物件上。藉由我們簡單易用的使用者操作介面，非製作動畫專家的初學者也能輕而易舉地控制雙面物件並且創造雙面動畫特效。

此外我們處理了單視圖建模和卡通頭髮動畫如此具有挑戰性的難題。我們的目標是將給定的卡通人物的頭髮給予建模，使它具有一致的層次感和遮蔽結果，使我們可以從只從單一圖像生產不同的視覺效果。我們提出了一個新的2.5D建模的方法來處理這樣的問題。輸入一張圖片，我們首先將卡通人物的頭髮進行切割成各自的區域。然後我們使用新穎的分層度量方法，它是基於格式塔心理學，自動優化頭髮之間的深度排序。在那之後，我們採用我們的頭髮修補方法，填補每塊頭髮被遮蔽的部分，創造卡通頭髮的2.5D模型。利用該模型，我們可以生產各種視覺效果，例如，我們開發了一個簡化的流體仿真運算製作風吹2.5D頭髮的動畫效果。為了進一步證明了該方法的適用性和通用性，我們的結果比較了真正的卡通的頭髮動畫，同時也運用我們的模型來產生各種各樣的頭髮造型，包括頭髮的編輯和頭髮編織。

在本文的最後，我們提出了一個平滑的循環變速且反覆的非對稱花紋的動畫模型，它是從幾何為基礎的流線來模擬正交推進波。它可以密集準確的視覺化現實世界上複雜的流場，藉由佈局優雅的流線動畫，產生視覺上享受的正交推進波。這個動畫模型首先沿著流線對速度做積分，算出亮度轉換函數。然後在流線間沿切線方向同步變換亮度。接著使用均勻間隔的色相差，在正交方向上構成切線方向條紋。此外提出了能量遞減策略，採用一種迭代尚未有效的程序，在HSL色空間中計算出每條流線的亮度和色調。然後我們更進一步在與向量場垂直的方向使用適應的交錯式明暗來增加流線條紋之間的對比。實驗結果顯示我們的動畫模型對於一些合成或是真實流場的視覺化都有幫助。

This dissertation introduces {em double-sided 2.5D graphics}, aiming at enriching the visual appearance when manipulating conventional 2D graphical objects in 2.5D worlds.
By attaching a back texture image on a single-sided 2D graphical object, we can enrich the surface and texture detail on 2D graphical objects and improve our visual experience when manipulating and animating them.
A family of novel operations on 2.5D graphics, including rolling, twisting, and folding, are proposed in this work, allowing users to efficiently create compelling 2.5D visual effects.
Very little effort is needed from the user's side.
In our experiment, various creative designs on double-sided graphics were worked out by the recruited participants including a professional artist, which show and demonstrate the feasibility and applicability of our proposed method.

Furthermore, we addresses a challenging single-view modeling and animation problem with cartoon images.
Our goal is to model the hairs in a given cartoon image with consistent layering and occlusion, so that we can produce various visual effects from just a single image.
We propose a novel 2.5D modeling approach to deal with this problem.
Given an input image, we first segment the hairs of the cartoon character into regions of hair strands.
Then, we apply our novel layering metric, which is derived from the Gestalt psychology, to automatically optimize the depth ordering among the hair strands.
After that, we employ our hair completion method to fill the occluded part of each hair strand, and create a 2.5D model of the cartoon hair.
By using this model, we can produce various visual effects, e.g., we develop a simplified fluid simulation model to produce wind blowing animations with the 2.5D hairs.
To further demonstrate the applicability and versatility of our method, we compare our results with real cartoon hair animations, and also apply our model to produce a wide variety of hair manipulation effects, including hair editing and hair braiding.

In the end, we present a smooth cyclic variable-speed Repeated Asymmetric Patterns (RAPs) animation model that emulates orthogonal advancing waves from a geometry-based flow representation. It enables dense accurate visualization of complex real world flows using animated streamlines of an elegant placement coupled with visually appealing orthogonal advancing waves. The animation model first performs velocity (magnitude) integral luminance transition on individual streamlines. Then, an inter-streamline synchronization in luminance varying along the tangential direction is imposed. Next, tangential flow streaks are constructed using evenly-spaced hue differing in the orthogonal direction. In addition, an energy-decreasing strategy is proposed that adopts an iterative yet efficient procedure for determining the luminance phase and hue of each streamline in HSL color space. To increase the contrast between flow streaks, an adaptive luminance interleaving in the direction perpendicular to the flow is further applied. We demonstrate the effectiveness of the animation model using some synthetic and real flows.

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