Scott A. King

Swirling-sweepers: constant volume modeling

Swirling-sweepers is a new method for modeling shapes while preserving volume. The artist describes a deformation by dragging a point along a path. The method is independent of the geometric representation of the shape. It preserves volume and avoids self-intersections, both local and global. It is capable of unlimited stretching and the deformation can be constrained to affect only apart of the model. We argue that all of these properties are necessary for interactive modeling if the user is to have the impression that he or she is shaping a real material. Our method is the first to implement all five.

Creating speech-synchronized animation

We present a facial model designed primarily to support animated speech. Our facial model takes facial geometry as input and transforms it into a parametric deformable model. The facial model uses a muscle-based parameterization, allowing for easier integration between speech synchrony and facial expressions. Our facial model has a highly deformable lip model that is grafted onto the input facial geometry to provide the necessary geometric complexity needed for creating lip shapes and high-quality renderings. Our facial model also includes a highly deformable tongue model that can represent the shapes the tongue undergoes during speech. We add teeth, gums, and upper palate geometry to complete the inner mouth. To decrease the processing time, we hierarchically deform the facial surface. We also present a method to animate the facial model over time to create animated speech using a model of coarticulation that blends visemes together using dominance functions. We treat visemes as a dynamic shaping of the vocal tract by describing visemes as curves instead of keyframes. We show the utility of the techniques described in this paper by implementing them in a text-to-audiovisual-speech system that creates animation of speech from unrestricted text. The facial and coarticulation models must first be interactively initialized. The system then automatically creates accurate real-time animated speech from the input text. It is capable of cheaply producing tremendous amounts of animated speech with very low resource requirements.

Swirling-sweepers: constant-volume modeling

Swirling-sweepers is a new method for modeling shapes while preserving volume. The artist describes a deformation by dragging a point along a path. The method is independent of the geometric representation of the shape. It preserves volume and avoids self-intersections, both local and global. It is capable of unlimited stretching and the deformation can be constrained to affect only apart of the model. We argue that all of these properties are necessary for interactive modeling if the user is to have the impression that he or she is shaping a real material. Our method is the first to implement all five.

A 3D parametric tongue model for animated speech

We present a tongue model for use in computer-animated speech. The model is capable of representing tongue shapes during the production of English vowels and consonants as well as general motion of the tongue. Geometrically, the model is composed of a B-spline surface with 60 control points and an 8r13 grid of bi-cubic patches. We also present a parameterization of the model that requires only six parameters for use during speech production. This parameterization can also be used to define the deformation of other tongue models. Copyright # 2001 John Wiley & Sons, Ltd.

Fast Volume Rendering and Animation of Amorphous Phenomena

Virtual environment technology, such as flight simulators, medical simulators and games, is making vast steps in realism and speed. For convincing interactive environments, gaseous effects, such as fire, dust and smoke, are needed. To achieve this realism, we have several design goals we wish to meet: Animation must support real-time applications; The method should be able to represent a variety of phenomena; The effect must occupy three-dimensional space; Other objects in the environment must be able to interact with the effect; A variety of shapes should be supported; The basic shape should allow for easy deformations or propagation.

Language-driven nonverbal communication in a bilingual conversational agent

This paper describes an animated conversational agent called Kare which integrates a talking head interface with a linguistically motivated human-machine dialogue system. The agent has a range of nonverbal behaviors, which involve a mixture of machine vision, computer animation and natural language processing techniques. The systems architecture couples the agents nonverbal communicative processes very tightly to its model of verbal interaction. We discuss several consequences of this architecture, in particular the ability to use different nonverbal dialogue management signals when speaking different languages.

Issues with lip sync animation: can you read my lips?

Lip-sync animation is complex and challenging. It promises to be important in natural human-computer interfaces and entertainment as well as aid in the education of the deaf. It is an important component in creating a realistic human figure. Speech is based on principles from anatomy, physics, and psychophysiology. We discuss some of the issues that make speech so complex to model visually.

Multisensory platform for surgical simulation

Advanced display technologies have made the virtual exploration of relatively complex models feasible in many applications. Unfortunately, only a few human interfaces allow natural interaction with the environment. Moreover in surgical applications, such realistic interaction requires real time rendering of volumetric data-placing an overwhelming performance burden on the system. We report on a collaboration of a unique interdisciplinary group developing a virtual reality system that provides intuitive interaction with complex volume data by employing real time realistic volume rendering and convincing force feedback (haptic) sensations. We describe our rendering methods and the haptic devices in detail and demonstrate the utilization of this system in the real world application of Endoscopic Sinus Surgery (ESS) simulation.

Simulating tree growth based on internal and environmental factors

This paper describes a method using L-systems that models tree growth based on the interaction of the trees internal attributes with themselves and with environmental conditions. Modeled components include chemical flow and water distribution within the tree, phototropism, space tropism, energy generation and usage, weight support, and self-pruning.Our system is described and many results are presented which show how the individual factors affect tree growth, and also how they interact with each other.

A system for real-time watercolour rendering

We present a system for the real-time rendering of scenes to produce images like watercolour paintings. Our system uses a hybrid of object space rendering techniques and image plane post processing to attain extremely good results very quickly. We achieve this through graphics processing unit (GPU) programming, hardware accelerated shadow volumes, and the use of noise for various different tasks. We manage to circumvent problems found in both previous image space and object space methods by combining the two.