Badler, Norman I

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Now showing 1 - 10 of 184
  • Publication
    Structure-Based Animation of the Human Face
    (1991-02-01) Platt, Stephen M; Smith, Aaron T; Azuola, Francisco; Badler, Norman I; Pelachaud, Catherine
    The face is an interesting object to animate for several reasons: it is an important channel of communication and therefore important to any human body animation, and it is a complex object in that it is composed of many nonrigid interacting nonarticulated regions. In this paper, we examine the face, and present it as as a hierarchically structured regionally defined object. Based on this regional decomposition, and a set of primitive actions, we describe an encoding of a large set of high level facial action descriptors. We also present an application which studies the interaction between intonation and facial expressions for a given emotion. It offers a higher level of representation of the action units by grouping them into specialized functions (lips shape for phonemes, eyebrow movements). An animation system linked to facial motion property is also presented.
  • Publication
    Anthropometry for Computer Graphics Human Figures
    (1989) Grosso, Marc R; Quach, Richard D.; Otani, Ernest; Zhao, Jianmin; Wei, Susanna; Ho, Pei-Hwa; Lu, Jiahe; Badler, Norman I
    Anthropometry as it applies to Computer Graphics is examined in this report which documents the Anthropometry work done in the Computer Graphics Research Laboratory at the University of Pennsylvania from 1986 to 1988. A detailed description of the basis for this work is given along with examples of the variability of computer graphics human figures resulting from this work. Also discussed is the unique and versatile user interface developed to allow easy manipulation of the data used to describe the anthropometric parameters required to define human figure models. The many appendices contain the specifics of our models as well as much of the data used to define the models.
  • Publication
    Interactive Behaviors for Bipedal Articulated Figures
    (1991) Phillips, Cary B.; Badler, Norman I
    We describe techniques for interactively controlling bipedal articulated figures through kinematic constraints. These constraints model certain behavioral tendencies which capture some of the characteristics of human-like movement, and give us control over such elements as the figures' balance and stability. They operate in near real-time, so provide behavioral control for interactive manipulation. These constraints form the basis of an interactive motion-generation system that allows the active movement elements to be layered on top of the passive behavioral constraints.
  • Publication
    A Gathering and Shooting Progressive Refinement Radiosity Method
    (1993) Shao, Min-Zhi; Badler, Norman I
    This paper presents a gathering and shooting progressive refinement radiosity method. Our method integrates the iterative process of light energy gathering used in the standard full matrix method and the iterative process of light energy shooting used in the conventional progressive refinement method. As usual, in each iteration, the algorithm first selects the patch which holds the maximum unprocessed light energy in the environment as the shooting patch. But before the shooting process is activated, a light energy gathering process takes place. In this gathering process, the amount of the unprocessed light energy which is supposed to be shot to the current shooting patch from the rest of the environment in later iterations is pre-accumulated. In general, this extra amount of gathered light energy is far from trivial since it comes from every patch in the environment from which the current shooting patch can be seen. However, with the reciprocity relationship for form-factors, still only one hemi-cube of the form-factors is needed in each iteration step. Based on a concise record of the history of the unprocessed light energy distribution in the environment, a new progressive refinement algorithm with revised gathering and shooting procedures is then proposed. With little additional computation and memory usage compared to the conventional progressive refinement radiosity method, a solid convergence speedup is achieved. This gathering and shooting approach extends the capability of the radiosity method in accurate and efficient simulation of the global illuminations of complex environments.
  • Publication
    Issues in Facial Animation
    (1990-11-01) Pelachaud, Catherine; Badler, Norman I; Steedman, Mark
    Our goal is to build a system of 3-D animation of facial expressions of emotion correlated with the intonation of the voice. Up till now, the existing systems did not take into account the link between these two features. Many linguists and psychologists have noted the importance of spoken intonation for conveying different emotions associated with speakers' messages. Moreover, some psychologists have found some universal facial expressions linked to emotions and attitudes. We will look at the rules that control these relations (intonation/emotions and facial expressions/emotions) as well as the coordination of these various modes of expressions. Given an utterance, we consider how the message (what is new/old information in the given context) transmitted through the choice of accents and their placement, are conveyed through the face. The facial model integrates the action of each muscle or group of muscles as well as the propagation of the muscles' movement. It is also adapted to the FACS notation (Facial Action Coding System) created by P. Ekman and W. Friesen to describe facial expressions. Our first step will be to enumerate and to differentiate facial movements linked to emotions from the ones linked to conversation. Then, we will examine what the rules are that drive them and how their different actions interact.
  • Publication
    Intermittent Non-Rhythmic Human Stepping and Locomotion
    (1993-05-01) Ko, Hyeongseok; Badler, Norman I
    When humans need to get from one location to another, there are many occasions where non-rhythmic stepping (NRS) is more desirable than normal walking. This can be observed in performing tasks in a constricted work space. For this purpose NRS is considered as a variation of curved path walking. Four types of local adjustment are dealt with: forward, backward, lateral stepping, and turnaround. Combined with curved path walking, NRS provides a very useful tool for animating human locomotion behaviors. In the lower body motion, the trajectory of the hip, angular trajectory of the feet, and the trajectory of the swing ankle during the swing phase determine the basic outline of an NRS. These trajectories are precomputed at the start of each step. The stepping process is called with a normalized time to generate the actual pose of the NRS at that moment. the normalized time is a logical time, covering zero to one during a complete step.
  • Publication
    A Low Cost Tactor Suit for Vibrotactile Feedback
    (2003-01-01) Bloomfield, Aaron; Badler, Norman I
    We constructed low cost tactors for vibrotactile feedback across the human arm for the purpose of providing a physical sensation surrogate for virtual objects. The tactors were built from readily available commercial parts, and provide low amplitude vibration for tactile feedback. The tactors are Velcro mounted on a custom suit designed to ensure localized sensations of each tactor. The suit is designed to be compatible with standard motion capture devices. Our suit provides 24 vibratory tactors in a tactor array on the user’s right arm and hand, and can easily be expanded to include the entire torso and body.
  • Publication
    Efforts in Preparation for Jack Validation
    (1997-12-01) Badler, Norman I; Azuola, Francisco; Huh, Suejung; Ho, Pei-Hwa; Kokkevis, Evangelos; Ting, Bond-Jay
    This document presents a detailed record of the methodologies, assumptions, limitations, and references used in creating the human figure model in Jack, a program that displays and manipulates articulated geometric figures. This report reflects current efforts to develop and refine Jack software to enable its validation and verification as a tool for performing human engineering analysis. These efforts include human figure model improvements, statistical anthropometric data processing methods, enhanced human figure model construction and measuring methods, and automated accomodation analysis. This report discusses basic details of building human models, model anthropometry, scaling, Jack anthropometry-based human models, statistical data processing, figure generation tools, anthropometric errors, inverse dynamics, smooth skin implementation, guidelines used in estimating landmark locations on the model, and recommendations for validating and verifying the Jack human figure model.
  • Publication
  • Publication
    Design Concepts for Automating Maintenance Instructions
    (2000-02-01) Badler, Norman I; Erignac, Charles A; McDonald, Patrick Vincent; Sanchez, Edgar; Boyle, Edward S
    This research task was performed under the Technology for Readiness and Sustainment (TRS) contract (F33615-99-D-6001) for the Air Force Research Laboratory (AFRL), Sustainment Logistics Branch (HESS) at Wright-Patterson AFB, OH. The period of performance spanned one year starting 29 January 1999. The objective of this task was to develop and demonstrate a framework that can support the automated validation and verification of aircraft maintenance Technical Orders (TOs). The research team examined all stages ofTO generation to determine which tasks most warranted further research. From that investigation, validation and verification of appropriate, safe, and correct procedure steps emerged as the primary research target. This process would be based on available computer-aided design (CAD) data, procedure step ordering from existing sources, and human models. This determination was based on which tasks could yield the greatest impact on the authoring process and offer the greatest potential economic benefits. The team then developed a research roadmap and outlined specific technologies to be addressed in possible subsequent Air Force research tasks. To focus on the potential technology integration of the validation and verification component into existing or future TO generation procedures, we defined a demonstration scenario. Using the Front Uplock Hook assembly from an F/A-18 as the subject, we examined task procedure steps and failures that could be exposed by automated validation tools. These included hazards to personnel, damage to equipment, and incorrect disassembly order. Using the Parameterized Action Representation (PAR) developed on previous projects for actions and equipment behaviors, we characterized procedure steps and their positive and negative consequences. Finally, we illustrated a hypothetical user interface extension to a typical Interactive Electronic Technical Manual (IETM) authoring system to demonstrate how this process might appear to the TO author.