2 5D Cartoon Animation and Animating Streamlines

Abstract

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

Date of Award	2015 Feb 12
Original language	English
Supervisor	Tong-Yee Lee (Supervisor)