Curve and surface framing for scientific visualization and domain dependent navigation

Thesis (Ph.D.) - Indiana University, Computer Science, 1996Curves and surfaces are two of the most fundamental types of objects in computer graphics. Most existing systems use only the 3D positions of the curves and surfaces, and the 3D normal directions of the surfaces, in the visualization process. In this dissertation, we attach moving coordinate frames to curves and surfaces, and explore several applications of these frames in computer graphics and scientific visualization. Curves in space are difficult to perceive and analyze, especially when they are densely clustered, as is typical in computational fluid dynamics and volume deformation applications. Coordinate frames are useful for exposing the similarities and differences between curves. They are also useful for constructing ribbons, tubes and smooth camera orientations along curves. In many 3D systems, users interactively move the camera around the objects with a mouse or other device. But all the camera control is done independently of the properties of the objects being viewed, as if the user is flying freely in space. This type of domain-independent navigation is frequently inappropriate in visualization applications and is sometimes quite difficult for the user to control. Another productive approach is to look at domain-specific constraints and thus to create a new class of navigation strategies. Based on attached frames on surfaces, we can constrain the camera gaze direction to be always parallel (or at a fixed angle) to the surface normal. Then users will get a feeling of driving on the object instead of flying through the space. The user's mental model of the environment being visualized can be greatly enhanced by the use of these constraints in the interactive interface. Many of our research ideas have been implemented in Mesh View, an interactive system for viewing and manipulating geometric objects. It contains a general purpose C++ library for nD geometry and supports a winged-edge based data structure. Dozens of examples of scientifically interesting surfaces have been constructed and included with the system

The Research and Development of a Multi-Resolution Geometry Modeler

With each generation of technology, computers become even more capable of rendering objects with an ever increasing number of polygons. As a result, the desire to add more details to a 3D model increases as well. Among the many tools provided by computer graphics software that an artist has at their disposal for adding detail to a 3D mesh is subdivision. Subdivision is the concept of subdividing one polygon into several more polygons, the consequence being that there are more data points on the mesh for the artist to manipulate. Computer graphics programs tend to use subdivision on whole areas of a mesh rather than single faces. This thesis will discuss the process and development of creating a program capable of subdividing individual faces on a given mesh, the idea being that the artist is in control of where they choose to subdivide in order to add more details to their 3D model. The goal of the project is to implement a software prototype that would make it easier for a user to efficiently manipulate mesh points and add details through subdivision. Essentially, a skilled artist could utilize the program to create something very complex out of something very simple

A Rigging Convention for Isosurface-Based Characters

This thesis presents a prototype system for generating animation control systems for isosurface-based characters that blurs the distinction between a skeletal rig and a particle system. Managing articulation and deformation set-up can be challenging for amorphous characters whose surface shape is defined at render time and can only be viewed as an approximation during the process of defining an animation performance. This prototype system utilizes conventional scripted techniques for defining animation control systems integrated with a graphical user interface that provides art directable control over surface contour, shape and silhouette for isosurface-based characters. Once animated, these characters can be rendered using Rendermans RIBlobby implementation and provide visual feedback of fluid motion tests. The prototype system fits naturally within common practices in digital character setup and provides the animator control over isosurface-based characters

EXTRACTING FLOW FEATURES USING BAG-OF-FEATURES AND SUPERVISED LEARNING TECHNIQUES

Measuring the similarity between two streamlines is fundamental to many important flow data analysis and visualization tasks such as feature detection, pattern querying and streamline clustering. This dissertation presents a novel streamline similarity measure inspired by the bag-of-features concept from computer vision. Different from other streamline similarity measures, the proposed one considers both the distribution of and the distances among features along a streamline. The proposed measure is tested in two common tasks in vector field exploration: streamline similarity query and streamline clustering. Compared with a recent streamline similarity measure, the proposed measure allows users to see the interesting features more clearly in a complicated vector field. In addition to focusing on similar streamlines through streamline similarity query or clustering, users sometimes want to group and see similar features from different streamlines. For example, it is useful to find all the spirals contained in different streamlines and present them to users. To this end, this dissertation proposes to segment each streamline into different features. This problem has not been studied extensively in flow visualization. For instance, many flow feature extraction techniques segment streamline based on simple heuristics such as accumulative curvature or arc length, and, as a result, the segments they found usually do not directly correspond to complete flow features. This dissertation proposes a machine learning-based streamline segmentation algorithm to segment each streamline into distinct features. It is shown that the proposed method can locate interesting features (e.g., a spiral in a streamline) more accurately than some other flow feature extraction methods. Since streamlines are space curves, the proposed method also serves as a general curve segmentation method and may be applied in other fields such as computer vision. Besides flow visualization, a pedagogical visualization tool DTEvisual for teaching access control is also discussed in this dissertation. Domain Type Enforcement (DTE) is a powerful abstraction for teaching students about modern models of access control in operating systems. With DTEvisual, students have an environment for visualizing a DTE-based policy using graphs, visually modifying the policy, and animating the common DTE queries in real time. A user study of DTEvisual suggests that the tool is helpful for students to understand DTE

Animating Film Theory

Animating Film Theory provides an enriched understanding of the relationship between two of the most unwieldy and unstable organizing concepts in cinema and media studies: animation and film theory. For the most part, animation has been excluded from the purview of film theory. The contributors to this collection consider the reasons for this marginalization while also bringing attention to key historical contributions across a wide range of animation practices, geographic and linguistic terrains, and historical periods. They delve deep into questions of how animation might best be understood, as well as how it relates to concepts such as the still, the moving image, the frame, animism, and utopia. The contributors take on the kinds of theoretical questions that have remained underexplored because, as Karen Beckman argues, scholars of cinema and media studies have allowed themselves to be constrained by too narrow a sense of what cinema is. This collection reanimates and expands film studies by taking the concept of animation seriously. Contributors. Karen Beckman, Suzanne Buchan, Scott Bukatman, Alan Cholodenko, Yuriko Furuhata, Alexander R. Galloway, Oliver Gaycken, Bishnupriya Ghosh, Tom Gunning, Andrew R. Johnston, Hervé Joubert-Laurencin, Gertrud Koch, Thomas LaMarre, Christopher P. Lehman, Esther Leslie, John MacKay, Mihaela Mihailova, Marc Steinberg, Tess Takahash

Animating Film Theory

Animating Film Theory provides an enriched understanding of the relationship between two of the most unwieldy and unstable organizing concepts in cinema and media studies: animation and film theory. For the most part, animation has been excluded from the purview of film theory. The contributors to this collection consider the reasons for this marginalization while also bringing attention to key historical contributions across a wide range of animation practices, geographic and linguistic terrains, and historical periods. They delve deep into questions of how animation might best be understood, as well as how it relates to concepts such as the still, the moving image, the frame, animism, and utopia. The contributors take on the kinds of theoretical questions that have remained underexplored because, as Karen Beckman argues, scholars of cinema and media studies have allowed themselves to be constrained by too narrow a sense of what cinema is. This collection reanimates and expands film studies by taking the concept of animation seriously. Contributors. Karen Beckman, Suzanne Buchan, Scott Bukatman, Alan Cholodenko, Yuriko Furuhata, Alexander R. Galloway, Oliver Gaycken, Bishnupriya Ghosh, Tom Gunning, Andrew R. Johnston, Hervé Joubert-Laurencin, Gertrud Koch, Thomas LaMarre, Christopher P. Lehman, Esther Leslie, John MacKay, Mihaela Mihailova, Marc Steinberg, Tess Takahash

컴퓨터를 활용한 여러 사람의 동작 연출

학위논문 (박사)-- 서울대학교 대학원 공과대학 전기·컴퓨터공학부, 2017. 8. 이제희.Choreographing motion is the process of converting written stories or messages into the real movement of actors. In performances or movie, directors spend a consid-erable time and effort because it is the primary factor that audiences concentrate. If multiple actors exist in the scene, choreography becomes more challenging. The fundamental difficulty is that the coordination between actors should precisely be ad-justed. Spatio-temporal coordination is the first requirement that must be satisfied, and causality/mood are also another important coordinations. Directors use several assistant tools such as storyboards or roughly crafted 3D animations, which can visu-alize the flow of movements, to organize ideas or to explain them to actors. However, it is difficult to use the tools because artistry and considerable training effort are required. It also doesnt have ability to give any suggestions or feedbacks. Finally, the amount of manual labor increases exponentially as the number of actor increases. In this thesis, we propose computational approaches on choreographing multiple actor motion. The ultimate goal is to enable novice users easily to generate motions of multiple actors without substantial effort. We first show an approach to generate motions for shadow theatre, where actors should carefully collaborate to achieve the same goal. The results are comparable to ones that are made by professional ac-tors. In the next, we present an interactive animation system for pre-visualization, where users exploits an intuitive graphical interface for scene description. Given a de-scription, the system can generate motions for the characters in the scene that match the description. Finally, we propose two controller designs (combining regression with trajectory optimization, evolutionary deep reinforcement learning) for physically sim-ulated actors, which guarantee physical validity of the resultant motions.Chapter 1 Introduction 1 Chapter 2 Background 8 2.1 Motion Generation Technique 9 2.1.1 Motion Editing and Synthesis for Single-Character 9 2.1.2 Motion Editing and Synthesis for Multi-Character 9 2.1.3 Motion Planning 10 2.1.4 Motion Control by Reinforcement Learning 11 2.1.5 Pose/Motion Estimation from Incomplete Information 11 2.1.6 Diversity on Resultant Motions 12 2.2 Authoring System 12 2.2.1 System using High-level Input 12 2.2.2 User-interactive System 13 2.3 Shadow Theatre 14 2.3.1 Shadow Generation 14 2.3.2 Shadow for Artistic Purpose 14 2.3.3 Viewing Shadow Theatre as Collages/Mosaics of People 15 2.4 Physics-based Controller Design 15 2.4.1 Controllers for Various Characters 15 2.4.2 Trajectory Optimization 15 2.4.3 Sampling-based Optimization 16 2.4.4 Model-Based Controller Design 16 2.4.5 Direct Policy Learning 17 2.4.6 Deep Reinforcement Learning for Control 17 Chapter 3 Motion Generation for Shadow Theatre 19 3.1 Overview 19 3.2 Shadow Theatre Problem 21 3.2.1 Problem Definition 21 3.2.2 Approaches of Professional Actors 22 3.3 Discovery of Principal Poses 24 3.3.1 Optimization Formulation 24 3.3.2 Optimization Algorithm 27 3.4 Animating Principal Poses 29 3.4.1 Initial Configuration 29 3.4.2 Optimization for Motion Generation 30 3.5 Experimental Results 32 3.5.1 Implementation Details 33 3.5.2 Animation 34 3.5.3 3D Fabrication 34 3.6 Discussion 37 Chapter 4 Interactive Animation System for Pre-visualization 40 4.1 Overview 40 4.2 Graphical Scene Description 42 4.3 Candidate Scene Generation 45 4.3.1 Connecting Paths 47 4.3.2 Motion Cascade 47 4.3.3 Motion Selection For Each Cycle 49 4.3.4 Cycle Ordering 51 4.3.5 Generalized Paths and Cycles 52 4.3.6 Motion Editing 54 4.4 Scene Ranking 54 4.4.1 Ranking Criteria 54 4.4.2 Scene Ranking Measures 57 4.5 Scene Refinement 58 4.6 Experimental Results 62 4.7 Discussion 65 Chapter 5 Physics-based Design and Control 69 5.1 Overview 69 5.2 Combining Regression with Trajectory Optimization 70 5.2.1 Simulation and Motor Skills 71 5.2.2 Control Adaptation 75 5.2.3 Control Parameterization 79 5.2.4 Efficient Construction 81 5.2.5 Experimental Results 84 5.2.6 Discussion 89 5.3 Example-Guided Control by Deep Reinforcement Learning 91 5.3.1 System Overview 92 5.3.2 Initial Policy Construction 95 5.3.3 Evolutionary Deep Q-Learning 100 5.3.4 Experimental Results 107 5.3.5 Discussion 114 Chapter 6 Conclusion 119 6.1 Contribution 119 6.2 Future Work 120 요약 135Docto

Parting A Read Sea Of Images: An Exploration Of Field Dependent-Independent Responses To Minimalist, Pictographic And Infographic Data Displays

ABSTRACT Western society reflects an âeikoncentric eraâ when contemporary instruction has become image -centered. Textbooks, journals, popular media as well as computer-based and web- based instructional media are filled by pictures that are intended to accomplish learning. Imagery is widely believed to represent an efficient, understandable method for relaying information and clarifying instruction for nearly all learners. However, those who subscribe to the adage âa picture is worth a thousand wordsâ often fail to acknowledge individual differences in visual comprehension and cognition. The field dependent-independent (FDI) cognitive style describes individual learner differences that can thwart visual learning. Information graphics are among the frequently used types of imagery that portray data. There is little empirical evidence to guide their design, and their creation is often based on intuition or opinion. This study researched the ways FDI learners comprehend and aesthetically assess minimalist information graphics, pictograms and infographics. Those participants who represented the most extreme field-dependent or field-independent learners were invited to participate in a two-part study. An instrument named the Comparative Information Graphic Test (CIG-T) was developed for testing comprehension of and perceived aesthetic efficacy, value and preference for minimalist information graphics, pictograms and infographics by FDI learner