Computer Animation '94., Proceedings of

We describe a method for modelling cartoon characters, so that the appearance of the character is separate from its movement. We introduce a conceptually simple primitive for modelling the appearance of a character. This primitive is based on NURBS. It is thus very general in what it can model. We also show that it is readily interpolated, for inbetweening. We discuss the interpolation method and ... View full abstract»

STORYBOARD is a scripting language for an interactive computer animation system. The language was designed to be simple in its use, to support various animation techniques provided by the animation environment, and to support procedural abstraction of animation. It is easily expandable and lends itself to the integration of interactive features of the system. Some of the important aspects of desig... View full abstract»

A constraint-based reasoning system is used for knowledge representation and reasoning in behavioural animation, specifically in the animation of sailing behaviour. The object-oriented ECHIDNA reasoning and constraint logic programming shell handles the constraints for formulation and execution of plans for intelligent entities. At higher levels of control, the observed motion of an object is a re... View full abstract»

Discretized representations of deformable objects, based upon simple dynamic point-mass systems, rely upon the propagation of forces between neighbouring elements to produce a global change in the shape of the surface. Attempting to make such a surface rigid produces stiff equations that are costly to evaluate with any numerical stability. This paper introduces a new multilevel approach for contro... View full abstract»

Computer animation of outdoor scenes is enhanced by realistic clouds. I discuss several different modelling and rendering schemes for clouds, and show how they evolved in my animation work. These include transparency-textured clouds on a 2D plane, smooth shaded or textured 3D cloud surfaces, and 3D volume rendering. For the volume rendering, I present various illumination schemes, including the de... View full abstract»

The scope of this paper is to propose a system for the automatic derivation of a human curved walking trajectory from the analysis provided by its synthetic vision module. The study context is a planar environment with still and sparse foothold locations. A general methodology associates the two low-level modules of vision and walking with a planification module which establishes the middle term p... View full abstract»

This paper presents a new image morphing technique using deformable surfaces. Drawbacks of previous techniques are overcome by a physically-based approach which provides an intuitive model for a warp. A warp is derived by two deformable surfaces which specify horizontal and vertical displacements of points on an image. This paper also considers the control of transition behavior in a metamorphosis... View full abstract»

We present a method to describe and visualize particle-systems using constructive solid geometry (CSG). Deformable objects simulations are easy to realize with coupled-particles. Motions are the results of time-integration of physical dynamics equations. In order to describe the physical objects, we add to the classic CSG-attributes, some that are not graphical. They allow the definition of physic... View full abstract»

The REALISM animation system encapsulates behavioural control mechanisms within the objects in a scene, offering a single interface to both modelling and animation. Libraries of actors allow creative skills to be focused on scene development and not individual object control. The progress of an animation sequence is defined by a controlling script. Individual object behaviour is defined by rules a... View full abstract»

High level tools to support the animation of multiple human figures make use of knowledge in a number of ways. Explicit knowledge, in the form of keyframes is supplied directly by the animator and procedural knowledge for repetitive movements like walking or grasping is built into the algorithms. However, the interaction of multiple figures in a complex environment requires a declarative knowledge... View full abstract»

A model for the dynamic simulation of flexible bodies subject to nonpenetration constraints is presented. Flexible bodies are described in terms of global deformations of a rest shape. The dynamical behavior of these bodies that most closely matches the behavior of ideal continuum bodies is derived, and subsumes the results of earlier Lagrangian dynamics-based models. The dynamics derived for the ... View full abstract»

The most important question that autonomous systems have to answer is how to remain viable in various and changing environments. This question is thus the same as how emerges the semiotic capacity to guess viable solutions, that is abduction. The aim of this paper is to sketch a theory both of sensorimotor autonomy and of the emergence of abductive capacities in the cases of reactive, hedonistic a... View full abstract»

A geometric and kinematic model for describing the global shape and the predominant motions of the human tongue, to be applied in computer animation, is discussed. The model consists of a spatial configuration of moving points that form the vertices of a mesh of 9 3-D triangles. These triangles are interpreted as charge centres (the so-called skeleton) for a potential field, and the surface of the... View full abstract»

Presents a method to reduce the time needed to render a sequence of ray traced images. We exploit the temporal and spatial coherence between consecutive frames. The algorithm does not only inspect the image plane in order to find regions with minor changes; the object space is analyzed by evaluating the so called ray history. With this method we obtain a speedup in the range of 1.2 to 2.8 almost w... View full abstract»

This paper is about ExTwAnPaSy, an Extensible Two-dimensional Animation/Paint System. ExTwAnPaSy is designed as a testbed for integrating various animation and painting techniques. Utilizing a uniform internal representation (and accompanying operations on it) for all geometric primitives, ExTwAnPaSy can integrate direct manipulation-, key-framing based-, as well as procedurally defined animation ... View full abstract»

We describe a real-time model of terrain traversal by simulated human agents. Agent navigation includes a variety of simulated sensors, terrain reasoning with behavioral constraints, and detailed simulation of a variety of locomotion techniques. The path through the terrain is incrementally computed by a behavioral reasoning system configuring a behavioral feedback network. A number of sensors acq... View full abstract»

While interpolating between successive postures of an articulated figure is not mathematically difficult, it is much more useful to provide postural transitions that are behaviorally reasonable and that avoid collisions with nearby objects. We describe such a posture interpolator which begins with a number of pre-defined static postures. A finite state machine controls the transitions from any pos... View full abstract»

This paper reviews various architectures or working principles that enable animals-i.e. simulated animals or animal-like robots-to display adaptive behaviors and that might be useful within the context of computer animation View full abstract»

This paper presents Langwidere, a facial animation system that integrates hierarchical spline modeling with simulated muscles based upon local area surface deformations. The multi-level shape representation of a hierarchical spline provides control over the extent of deformations, while at the same time reducing the amount of data needed to define the surface. The facial model is constructed from ... View full abstract»

We are interested in being able to take classic film characters, or video of current-day personalities, and produce computer models and animations of them by automatic analysis of the video or film footage. In this paper we survey our progress toward producing such automatic modeling and animation systems View full abstract»

Most of the earlier and existing computational models for facial animation consider only muscular expressions. We address and emphasize issues related to modeling of vascular expression. The proposed model enables visual characteristics such as skin color to change with time and provide visual clues for emotions like paleness and blushing. An emotion is defined as a function of two signals in time... View full abstract»

Austria is celebrating its millennium in 1996: although Austria is much older than 1000 years, the German name for Austria (Ostarici) is first found in a written document dated 996. For this celebration, one of the most ambitious networked multimedia presentations ever is currently being developed. For the name of the project, the acronym AEIOU has been chosen: one may read this as “Annotata... View full abstract»