Animating jellyfish through numerical simulation and symmetry exploitation

This thesis presents an automatic animation system for jellyfish that is based on a physical simulation of the organism and its surrounding fluid. Our goal is to explore the unusual style of locomotion, namely jet propulsion, which is utilized by jellyfish. The organism achieves this propulsion by contracting its body, expelling water, and propelling itself forward. The organism then expands again to refill itself with water for a subsequent stroke. We endeavor to model the thrust achieved by the jellyfish, and also the evolution of the organism's geometric configuration. We restrict our discussion of locomotion to fully grown adult jellyfish, and we restrict our study of locomotion to the resonant gait, which is the organism's most active mode of locomotion, and is characterized by a regular contraction rate that is near one of the creature's resonant frequencies. We also consider only species that are axially symmetric, and thus are able to reduce the dimensionality of our model. We can approximate the full 3D geometry of a jellyfish by simulating a 2D slice of the organism. This model reduction yields plausible results at a lower computational cost. From the 2D simulation, we extrapolate to a full 3D model. To prevent our extrapolated model from being artificially smooth, we give the final shape more variation by adding noise to the 3D geometry. This noise is inspired by empirical data of real jellyfish, and also by work with continuous noise functions from the graphics community. Our 2D simulations are done numerically with ideas from the field of computational fluid dynamics. Specifically, we simulate the elastic volume of the jellyfish with a spring-mass system, and we simulate the surrounding fluid using the semi-Lagrangian method. To couple the particle-based elastic representation with the grid-based fluid representation, we use the immersed boundary method. We find this combination of methods to be a very efficient means of simulating the 2D slice with a minimal compromise in physical accuracy

Computer-Assisted Interactive Documentary and Performance Arts in Illimitable Space

This major component of the research described in this thesis is 3D computer graphics, specifically the realistic physics-based softbody simulation and haptic responsive environments. Minor components include advanced human-computer interaction environments, non-linear documentary storytelling, and theatre performance. The journey of this research has been unusual because it requires a researcher with solid knowledge and background in multiple disciplines; who also has to be creative and sensitive in order to combine the possible areas into a new research direction. [...] It focuses on the advanced computer graphics and emerges from experimental cinematic works and theatrical artistic practices. Some development content and installations are completed to prove and evaluate the described concepts and to be convincing. [...] To summarize, the resulting work involves not only artistic creativity, but solving or combining technological hurdles in motion tracking, pattern recognition, force feedback control, etc., with the available documentary footage on film, video, or images, and text via a variety of devices [....] and programming, and installing all the needed interfaces such that it all works in real-time. Thus, the contribution to the knowledge advancement is in solving these interfacing problems and the real-time aspects of the interaction that have uses in film industry, fashion industry, new age interactive theatre, computer games, and web-based technologies and services for entertainment and education. It also includes building up on this experience to integrate Kinect- and haptic-based interaction, artistic scenery rendering, and other forms of control. This research work connects all the research disciplines, seemingly disjoint fields of research, such as computer graphics, documentary film, interactive media, and theatre performance together.Comment: PhD thesis copy; 272 pages, 83 figures, 6 algorithm

Virtual Ethology: Simulation of Aquatic Animal Heterogeneous Behaviours as Particle-Based Autonomous Agents

In the virtual world, the simulation of flocking behaviour has been actively investigated since the 1980 through the boid models. However, ethology is a niche study of animal behaviour from the biological perspective that is rarely instil in the interest of the younger learners nowadays. The keystone of the research is to be able to disseminate the study of animal behaviours through the boid model with the aid of technology. Through the simulation, complex movement of animal behaviours are reproduced based on the extension of basic behaviours of boid algorithm. The techniques here are to (i) Analyse a high-level behavioural framework of motion in the animal behaviours and (ii) Evolves particles to other animal representations to portray more real-time examples of steering behaviours. Although the generality of the results is limited by the number of case study, it also supports the hypothesis that interactive simulation system of virtual ethology can aid the improvement of animal studie

A RULE-BASED APPROACH TO ANIMATING MULTI-AGENT ENVIRONMENTS

This dissertation describes ESCAPE (Expert Systems in Computer Animation Production Environments), a multi-agent animation system for building domain-oriented, rule-based visual programming environments. Much recent work in computer graphics has been concerned with producing behavioural animations of artificial life-forms mainly based on algorithmic approaches. This research indicates how, by adding an inference engine and rules that describe such behaviour, traditional computer animation environments can be enhanced. The comparison between using algorithmic approaches and using a rule-based approach for representing multi-agent worlds is not based upon their respective claims to completeness, but rather on the ease with which end users may express their knowledge and control their animations with a minimum of technical knowledge. An environment for the design of computer animations incorporating an expert system approach is described. In addition to direct manipulation of objects on the screen, the environment allows users to describe behavioural rules based upon both the physical and non-physical attributes of objects. These rules can be interpreted to suggest the transition from stage to stage or to automatically produce a longer animation. The output from the system can be integrated into a commercially available 3D modelling and rendering package. Experience indicates that a hybrid environment, mixing algorithmic and rule-based approaches, would be very promising and offer benefits in application areas such as creating realistic background scenes and modelling human beings or animals either singly or in groups. A prototype evaluation system and three different domains are described and illustrated with preliminary animated images

Magnetic-field-induced propulsion of jellyfish-inspired soft robotic swimmers

The multifaceted appearance of soft robots in the form of swimmers, catheters, surgical devices, and drug-carrier vehicles in biomedical and microfluidic applications is ubiquitous today. Jellyfish-inspired soft robotic swimmers (jellyfishbots) have been fabricated and experimentally characterized by several researchers that reported their swimming kinematics and multimodal locomotion. However, the underlying physical mechanisms that govern magnetic-field-induced propulsion are not yet fully understood. Here, we use a robust and efficient computational framework to study the jellyfishbot swimming kinematics and the induced flow field dynamics through numerical simulation. We consider a two-dimensional model jellyfishbot that has flexible lappets, which are symmetric about the jellyfishbot center. These lappets exhibit flexural deformation when subjected to external magnetic fields to displace the surrounding fluid, thereby generating the thrust required for propulsion. We perform a parametric sweep to explore the jellyfishbot kinematic performance for different system parameters—structural, fluidic, and magnetic. In jellyfishbots, the soft magnetic composite elastomeric lappets exhibit temporal and spatial asymmetries when subjected to unsteady external magnetic fields. The average speed is observed to be dependent on both these asymmetries, quantified by the glide magnitude and the net area swept by the lappet tips per swimming cycle, respectively. We observe that a judicious choice of the applied magnetic field and remnant magnetization profile in the jellyfishbot lappets enhances both these asymmetries. Furthermore, the dependence of the jellyfishbot swimming speed upon the net area swept (spatial asymmetry) is twice as high as the dependence of speed on the glide ratio (temporal asymmetry). Finally, functional relationships between the swimming speed and different kinematic parameters and nondimensional numbers are developed. Our results provide guidelines for the design of improved jellyfish-inspired magnetic soft robotic swimmers

From Single Neurons to Behavior in the Jellyfish Aurelia aurita

Jellyfish nerve nets provide insight into the origins of nervous systems, as both their taxonomic position and their evolutionary age imply that jellyfish resemble some of the earliest neuron-bearing, actively-swimming animals. Here we develop the first neuronal network model for the nerve nets of jellyfish. Specifically, we focus on the moon jelly Aurelia aurita and the control of its energy-efficient swimming motion. The proposed single neuron model disentangles the contributions of different currents to a spike. The network model identifies factors ensuring non-pathological activity and suggests an optimization for the transmission of signals. After modeling the jellyfish's muscle system and its bell in a hydrodynamic environment, we explore the swimming elicited by neural activity. We find that different delays between nerve net activations lead to well-controlled, differently directed movements. Our model bridges the scales from single neurons to behavior, allowing for a comprehensive understanding of jellyfish neural control

NASA CORE: Central Operation of Resources for Educators-Educational Materials Catalog

The NASA Central Operation of Resources for Educators (CORE), established in cooperation with Lorain County Joint Vocational School, serves as the worldwide distribution center for NASA-produced educational materials. For a minimal charge, CORE will provide a valuable service to educators unable to visit one of the NASA Educator Resource Centers by making NASA educational audiovisual materials available through its mail order service. Through CORE's distribution network, the public has access to more than 200 videocassette, slide, and CD-ROM programs, chronicling NASA!s state-of-the-art research and technology. Through the use of these curriculum supplement materials, teachers can provide their students with the latest in aerospace information. NASAs educational materials on aeronautics and space provide a springboard for classroom discussion of life science, physical science, astronomy, energy, Earth resources, environment, mathematics, and career education

An Approach To Painterly Rendering

An often overlooked key component of 3D animations is the rendering engine. However, some rendering techniques are hard to implement or are too restrictive in terms of the imagery they can produce. The goal of this thesis is to make easy-to-use software that artists can use to create stylistic animations and that also minimizes technical constraints placed on the art. For this project, I present a tool that allows artists to create temporally coherent, painterly animations using Autodesk Maya and Corel Painter. I then use that tool to create proof of concept animations. This new rendering technique offers artists a different avenue through which they can showcase their art and also offers certain freedoms that current computer graphics techniques lack. Accompanying this paper are some animations demonstrating possible outcomes, and they are located on the Texas A&M online library catalog system. The painting system used for this project expands upon an algorithm designed by Barbara Meier of the Disney Research Group that involves spreading particles across a surface and using those particles to define brush strokes. The first step is to infer the general syntax of Painter’s commands by using Painter and its ability to record a painting made by an artist. The next step is to use the commands and syntax that Painter uses in the automated creation of scripts to generate paintings used for the animation. As this thesis is designed to showcase a rendering technique, I found animations made by fellow candidates for the Master of Science and Master of Fine Arts degrees in Visualization bearing qualities accented by a painterly treatment and rendered them using this technique

Towards a Phenomenological Theory of the Visceral in the Interactive Arts

This is a digitised version of a thesis that was deposited in the University Library. If you are the author and you have a query about this item please contact PEARL Admin ([email protected])Metadata merged with duplicate record (http://hdl.handle.net/10026.1/2319) on 20.12.2016 by CS (TIS).This thesis explores the ways in which certain forms of interactive art may and do elicit visceral responses. The term "visceral" refers to the cardiovascular, respiratory, uro-genital and especially excretory systems that affect mind and body on a continuum of awareness. The "visceral" is mentioned in the field of interactive arts, but it remains systematically unexplored and undefined. Further, interactive artworks predominantly focus on the exteroceptive (stimuli from outside) rather than the interoceptive (stimuli arising within the body, especially the viscera) senses. The existentialist phenomenology of Maurice Merleau-Ponty forms the basis for explorations of the visceral dimension of mind/body. New approaches to understanding interactive art, design and the mind/body include: attunements to the world; intertwinings of mind/body, technology and world; and of being in the world. Each artwork within utilizes a variation of the phenomenological methods derived from Merl eau-Ponty's; these are discussed primarily in Chapters One and Three. Because subjective, first-person, experiences are a major aspect of a phenomenological approach, the academic writing is interspersed with subjective experiences of the author and others. This thesis balances facets of knowledge from diverse disciplines that account for visceral phenomena and subjective experience. Along with the textual exegesis, one major work of design and two major works of art were created. These are documented on the compact disc (CDROM) bound within. As an essential component of each artwork, new technological systems were created or co-created by the author. User surveys comprise Appendices Two, Three and Four, and are also online at: www. sfu. ca/-dgromala/thesis. To access the URL: login as , and use the password . Numerous talks, exhibitions and publications that directly relate to the thesis work is in Appendix One. This work begins with an introduction to Merleau-Ponty's ideas of flesh and reversibility. Chapter Two is the review of the literature, while Chapter Three is an explication of the hypothesis, an overview of the field, and a framing of the problem. Discussions of each artwork are in Chapter Four (The Meditation Chamber), Chapter Five (BioMorphic Typography) and Chapter Six (The MeatBook). Chapter Seven forms the conclusion. References to the documentation on the CD are found throughout the thesis, and italicized paragraphs provide an artistic context for each chapter

Vector offset operators for deformable organic objects.

Many natural materials and most of living tissues exhibit complex deformable behaviours that may be characteriseda s organic. In computer animation, deformable organic material behaviour is needed for the development of characters and scenes based on living creatures and natural phenomena. This study addresses the problem of deformable organic material behaviour in computer animated objects. The focus of this study is concentrated on problems inherent in geometry based deformation techniques, such as non-intuitive interaction and difficulty in achieving realism. Further, the focus is concentrated on problems inherent in physically based deformation techniques, such as inefficiency and difficulty in enforcing spatial and temporal constraints. The main objective in this study is to find a general and efficient solution to interaction and animation of deformable 3D objects with natural organic material properties and constrainable behaviour. The solution must provide an interaction and animation framework suitable for the creation of animated deformable characters. An implementation of physical organic material properties such as plasticity, elasticity and iscoelasticity can provide the basis for an organic deformation model. An efficient approach to stress and strain control is introduced with a deformation tool named Vector Offset Operator. Stress / strain graphs control the elastoplastic behaviour of the model. Strain creep, stress relaxation and hysteresis graphs control the viscoelastic behaviour of the model. External forces may be applied using motion paths equipped with momentum / time graphs. Finally, spatial and temporal constraints are applied directly on vector operators. The suggested generic deformation tool introduces an intermediate layer between user interaction, deformation, elastoplastic and viscoelastic material behaviour and spatial and temporal constraints. This results in an efficient approach to deformation, frees object representation from deformation, facilitates the application of constraints and enables further development