运用动画技术展现霾灾害的优势

霾作为一种近年来频发、危害性广的灾害性的天气现象,对于人体的危害不容忽视。如何普及霾的基本常识、提高人们在雾霾天气中的自我防护和保健能力,成为社会大众迫切需要。动画作为影视艺术的分支,它综合了文学、美术、摄影、影视、音乐、戏剧、表演等多种艺术形式,不仅有着电影所具有的基本特性,也有电影无法达到的优势。将霾等天气现象以动画形式展现,把复杂深奥的气象知识以形象逼真、幽默夸张的创作手法表现出来,并通过新兴传播媒介比如数字电视、卫星电视、手机短信、互联网等手段进行传播普及,是当今科普动画发展的主流。     

Scalar-field-guided adaptive shape deformation and animation

In this paper, we propose a novel scalar-field-guided adaptive shape deformation (SFD) technique founded on PDE-based flow constraints and scalar fields of implicit functions. Scalar fields are used as embedding spaces. Upon deformation of the scalar field, a corresponding displacement/velocity field will be generated accordingly, which results in a shape deformation of the embedded object. In our system, the scalar field creation, sketching, and manipulation are both natural and intuitive. The embedded model is further enhanced with self-optimization capability. During the deformation we can also enforce various constraints on embedded models. In addition, this technique can be used to ease the animation design. Our experiments demonstrate that the new SFD technique is powerful, efficient, versatile, and intuitive for shape modeling and animation. This revised version was published online in February 2004 due to typesetting mistakes in the author correction process.     

Physically-based facial modelling,analysis, and animation

We develop a new 3D hierarchical model of the human face. The model incorporates a physically-based approximation to facial tissue and a set of anatomically-motivated facial muscle actuators. Despite its sophistication, the model is efficient enough to produce facial animation at interactive rates on a high-end graphics workstation. A second contribution of this paper is a technique for estimating muscle contractions from video sequences of human faces performing expressive articulations. These estimates may be input as dynamic control parameters to the face model in order to produce realistic animation. Using an example, we demonstrate that our technique yields sufficiently accurate muscle contraction estimates for the model to reconstruct expressions from dynamic images of faces.     

Simulating the structure and dynamics of human hair: Modelling,rendering and animation

We develop and present a new approach to modelling the characteristics of human hair, considering not only its structure, but also the control of its motion and a technique for rendering it in a realistic form. The approach includes a system for interactively defining the global positioning of the strands of hair on the head. Special attention is paid to the self shadowing of the hair. A mass/spring/hinge system is used to control a single strand's position and orientation. We demonstrate that this approach results in a believable rendition of the hair and its dynamics.     

Flash动画设计与传统动画设计的特点比较研究

随着现如今的经济水平的不断提高和发展,人们对于生活品质当中的追求不仅仅停留在物质的层面上,更多地开始关注精神文化方面的享受。动画是人们精神世界中不可忽视的重要组成部分,传统动画凭借其细腻的风格,开辟了我国动画事业的第一战场,也推动了flash动画的发展,但二者之中存在着许多特点方面的差异性。     

A framework for interactive responsive animation

The availability of high‐performance 3D workstations has increased the range of application for interactive real‐time animation. In these applications the user can directly interact with the objects in the animation and direct the evolution of their motion, rather than simply watching a pre‐computed animation sequence. Interactive real‐time animation has fast‐growing applications in virtual reality, scientific visualization, medical training and distant learning. Traditional approaches to computer animation have been based on the animator having complete control over all aspects of the motion. In interactive animation the user can interact with any of the objects, which changes the current motion path or behaviour in real time. The objects in the animation must be capable of reacting to the user's actions and not simply replay a canned motion sequence. This paper presents a framework for interactive animation that allows the animator to specify the reactions of objects to events generated by other objects and the user. This framework is based on the concept of relations that describe how an object reacts to the influence of a dynamic environment. Each relation specifies one motion primitive triggered by either its enabling condition or the state of the environment. A collection of the relations is structured through several hierarchical layers to produce responsive behaviours and their variations. This framework is illustrated by several room‐based dancing examples that are modelled by relations. Copyright © 2000 John Wiley & Sons, Ltd.     

The program animation system PASTIS

The software animation system PASTIS (Program Animation System with Interactive Solutions) for program animation with emphasis on the visualization of the dynamic behaviour of algorithms and data structures is presented. Its main properties are unmodified source code of the visualized program, concurrent multiple views on algorithms and data structures, and interactive alterations of views during run time. PASTIS is distinguished by high modularity and strict separation of its components. This makes it particularly suitable for distributed computing environments. The interface between program and animation is a relational data model. Animations are directed by a single tuple, or sets of tuples, called relations, or sets of relations, called networks. Animations can be nested hierarchically. A prototype of PASTIS was implemented under Unix

1 Unix is a trademark of AT&T.

using the GNU source level debugger gdb and the X-window system.     

Physically‐based forehead animation including wrinkles

Physically‐based animation techniques enable more realistic and accurate animation to be created. We present a fully physically‐based approach for efficiently producing realistic‐looking animations of facial movement, including animation of expressive wrinkles. This involves simulation of detailed voxel‐based models using a graphics processing unit‐based total Lagrangian explicit dynamic finite element solver with an anatomical muscle contraction model, and advanced boundary conditions that can model the sliding of soft tissue over the skull. The flexibility of our approach enables detailed animations of gross and fine‐scale soft‐tissue movement to be easily produced with different muscle structures and material parameters, for example, to animate different aged skins. Although we focus on the forehead, our approach can be used to animate any multi‐layered soft body. © 2014 The Authors. Computer Animation and Virtual Worlds published by John Wiley & Sons, Ltd.     

Monolithic Friction and Contact Handling for Rigid Bodies and Fluids Using SPH

We propose a novel monolithic pure SPH formulation to simulate fluids strongly coupled with rigid bodies. This includes fluid incompressibility, fluid–rigid interface handling and rigid–rigid contact handling with a viable implicit particle-based dry friction formulation. The resulting global system is solved using a new accelerated solver implementation that outperforms existing fluid and coupled rigid–fluid simulation approaches. We compare results of our simulation method to analytical solutions, show performance evaluations of our solver and present a variety of new and challenging simulation scenarios.     

A dynamic animation engine for generic spline objects

This paper introduces an accurate and efficient engine whose purpose is the dynamic animation of curvilinear objects which are modelled as successions of splines. At each time step the object shape conforms to its spline definitions, thus ensuring that each property implied by the chosen spline models is verified. This is achieved by animating spline control points. However, these control points are not considered as material points but rather as the degrees of freedom of the continuous object. The chosen dynamic equations (Lagrangian formalism) reflect this modelling scheme and yield an exact and very proficient linear system. In the chosen formalism, forces are introduced by either their potential energy or their power ratings in the virtual movements instilled by the degrees of freedom. Both methods are carried out in three cases: gravity, viscosity and generic force. Suitable and classical methods for constraint handling and numerical resolution are briefly discussed. Finally, this animation engine is applied to knitted patterns. Copyright © 2000 John Wiley & Sons, Ltd.     

Solid spaces and inverse particle systems for controlling the animation of gases and fluids

This paper describes a new system for controlling the animation of gases, liquids, and volume density functions. This system is extremely powerful and flexible. It allows for the control of animation effects ranging from physically based motion of gases to the choreographed motion of gases. These techniques make extensive use of three-dimensional tables, including both flow vectors and motion functions for controlling gas animation. This new system uses aninverse particle system, where each point in three-dimensional screen space (image space discretized to pixel locations) is moved through a gas space to determine which portion of the gas occupies the current location in screen space.     

基于ActionScript 3.0的Flash动画设计与制作

Flash动画以其强大的表现力和小巧的体积成为网络动画的首选软件。特别是脚本语言ActionScript 3.0版本功能的增强,使Flash表现出了强大的交互性,用户由单纯的观看欣赏动画逐步过渡到体验动画中。可以借助设计环境制作绚丽的动画效果,也可以改制成一个完整的Web站点,甚至完成一个丰富网络应用(Rich Internet Application,RIA)项目。本文以ActionScript 3.0脚本为切入点,介绍其在Flash动画设计与制作带来的巨大优势,并引入具体案例来加以说明其区别于传统Flash动画之处,领略其独特魅力。     

基于Maya的人物动画研究

为了对二维图像实现人物动画,对人物图像进行轮廓提取、贴图,给模型添加骨骼并进行骨骼绑定,最后进行人物动画模拟。实验结果表明,基于Maya的人物动画能够以较高真实度生成人物动画。     

汉语语音同步的三维口型动画研究

针对汉语的发音习惯以及语音可视化技术中对口型动画自然、连续的要求,提出了一种基于肌肉模型与协同发音模型的与语音保持同步的口型动画的方法.首先,根据汉语发音时的口型视位特征将声、韵母音素归类,并用数据映射的方式合成与之对应的口型关键帧.通过分析输入的文本信息,合成与语音保持同步的三维人脸口型动画.为了解决汉语发音习惯的问题,设计了一种基于微分几何学描述的协同发音建模的方法,该方法通过分析相邻音子间视素的影响权重,可以产生符合汉语发音习惯的口型动画.最后,通过实验对比和分析,该方法产生的口型动画更为逼真,且符合汉语发音的习惯.     

An embodied approach to arthropod animation

We describe a system for dynamically animating the locomotive behaviour of arthropods (insects, spiders and numerous other species) in real‐time, facilitating realistic and autonomous traversal across an arbitrary environment. By combining a decentralised reactive behavioural model with a hybrid approach to motion that utilises the comparative advantages of physical simulation and kinematic control, our system is capable of automatically generating complex organic motion over a wide range of surface features, independent of structural complexity. The reactive embodiment of the creature, combined with the physical simulation of the virtual world enables the formation of emergent behaviours that are entirely based on circumstance, including rigid‐body interaction, grip recovery and adaptive wall climbing. Copyright © 2012 John Wiley & Sons, Ltd.     

Facial animation based on context-dependent visemes

This paper presents a novel approach for the generation of realistic speech synchronized 3D facial animation that copes with anticipatory and perseveratory coarticulation. The methodology is based on the measurement of 3D trajectories of fiduciary points marked on the face of a real speaker during the speech production of CVCV non-sense words. The trajectories are measured from standard video sequences using stereo vision photogrammetric techniques. The first stationary point of each trajectory associated with a phonetic segment is selected as its articulatory target. By clustering according to geometric similarity all articulatory targets of a same segment in different phonetic contexts, a set of phonetic context-dependent visemes accounting for coarticulation is identified. These visemes are then used to drive a set of geometric transformation/deformation models that reproduce the rotation and translation of the temporomandibular joint on the 3D virtual face, as well as the behavior of the lips, such as protrusion, and opening width and height of the natural articulation. This approach is being used to generate 3D speech synchronized animation from both natural and synthetic speech generated by a text-to-speech synthesizer.     

Facial animation retargeting and control based on a human appearance space

Expressive facial animations are essential to enhance the realism and the credibility of virtual characters. Parameter‐based animation methods offer a precise control over facial configurations while performance‐based animation benefits from the naturalness of captured human motion. In this paper, we propose an animation system that gathers the advantages of both approaches. By analyzing a database of facial motion, we create the human appearance space. The appearance space provides a coherent and continuous parameterization of human facial movements, while encapsulating the coherence of real facial deformations. We present a method to optimally construct an analogous appearance face for a synthetic character. The link between both appearance spaces makes it possible to retarget facial animation on a synthetic face from a video source. Moreover, the topological characteristics of the appearance space allow us to detect the principal variation patterns of a face and automatically reorganize them on a low‐dimensional control space. The control space acts as an interactive user‐interface to manipulate the facial expressions of any synthetic face. This interface makes it simple and intuitive to generate still facial configurations for keyframe animation, as well as complete temporal sequences of facial movements. The resulting animations combine the flexibility of a parameter‐based system and the realism of real human motion. Copyright © 2010 John Wiley & Sons, Ltd.