Agnes Daldegan

Bio: Agnes Daldegan is an academic researcher from University of Geneva. The author has contributed to research in topics: Software rendering & Texture mapping. The author has an hindex of 3, co-authored 3 publications receiving 178 citations.

An integrated system for modeling, animating and rendering hair

Abstract: There are basically four problems to solve in order to produce realistic animated synthetic actors with hair: hair modeling and creation, hair motion, collision detection and hair rendering. The authors describe a complete methodology to solve these basic four problems. They present how hair styles may be designed with a Hair Styler module. They survey the animation model and emphasize a method of collision processing. Finally, they explain how hair may be rendered using an extension of a standard ray-tracing program. Applications of synthetic actors with various hair styles and different styles of mustaches and beards are shown

Creating Virtual Fur and Hair Styles for Synthetic Actors

Abstract: In this paper, we discuss both the aesthetic and technical concerns involved in the creation of synthetic hair and fur using our Styler and Hair Rendering software. Both pieces of software described in this paper were originally conceived for creating any kind of hair and rendering images of natural-looking hair. Taking advantage of the impressive realism of these images, we present in this paper an exploration of the software’s capacity to improve the appearence and quality of hair in synthetic human images, one of our main research areas.

Super-helices for predicting the dynamics of natural hair

Abstract: Simulating human hair is recognized as one of the most difficult tasks in computer animation. In this paper, we show that the Kirchhoff equations for dynamic, inextensible elastic rods can be used for accurately predicting hair motion. These equations fully account for the nonlinear behavior of hair strands with respect to bending and twisting. We introduce a novel deformable model for solving them: each strand is represented by a Super-Helix, i.e., a piecewise helical rod which is animated using the principles of Lagrangian mechanics. This results in a realistic and stable simulation, allowing large time steps. Our second contribution is an in-depth validation of the Super-Helix model, carried out through a series of experiments based on the comparison of real and simulated hair motions. We show that our model efficiently handles a wide range of hair types with a high level of realism.

A Survey on Hair Modeling: Styling, Simulation, and Rendering

Abstract: Realistic hair modeling is a fundamental part of creating virtual humans in computer graphics. This paper surveys the state of the art in the major topics of hair modeling: hairstyling, hair simulation, and hair rendering. Because of the difficult, often unsolved problems that arise in alt these areas, a broad diversity of approaches is used, each with strengths that make it appropriate for particular applications. We discuss each of these major topics in turn, presenting the unique challenges facing each area and describing solutions that have been presented over the years to handle these complex issues. Finally, we outline some of the remaining computational challenges in hair modeling

Modeling Dynamic Hair as a Continuum

Abstract: In this paper we address the difficult problem of hair dynamics, particularly hair-hair and hair-air interactions. To model these interactions, we propose to consider hair volume as a continuum. Subsequently, we treat the interaction dynamics to be fluid dynamics. This proves to be a strong as well as viable approach for an otherwise very complex phenomenon. However, we retain the individual character of hair, which is vital to visually realistic rendering of hair animation. For that, we develop an elaborate model for stiffness and inertial dynamics of individual hair strand. Being a reduced coordinate formulation, the stiffness dynamics is numerically stable and fast. We then unify the continuum interaction dynamics and the individual hair’s stiffness dynamics.

An integrated system for modeling, animating and rendering hair

Abstract: There are basically four problems to solve in order to produce realistic animated synthetic actors with hair: hair modeling and creation, hair motion, collision detection and hair rendering. The authors describe a complete methodology to solve these basic four problems. They present how hair styles may be designed with a Hair Styler module. They survey the animation model and emphasize a method of collision processing. Finally, they explain how hair may be rendered using an extension of a standard ray-tracing program. Applications of synthetic actors with various hair styles and different styles of mustaches and beards are shown

Knotting/Unknotting Manipulation of Deformable Linear Objects

Abstract: Here, we propose a planning method for knotting/unknotting of deformable linear objects. First, we propose a topological description of the state of a linear object. Second, transitions between these states are defined by introducing four basic operations. Then, possible sequences of crossing state transitions, i.e. possible manipulation processes, can be generated once the initial and the objective states are given. Third, a method for determining grasping points and their directions of movement is proposed to realize derived manipulation processes. Our proposed method indicated that it is theoretically possible for any knotting manipulation of a linear object placed on a table to be realized by a one-handed robot with three translational DOF and one rotational DOF. Furthermore, criteria for evaluation of generated plans are introduced to reduce the candidates of manipulation plans. Fourth, a planning method for tying knots tightly is established because they fulfill their fixing function by tightening them. Finally, we report knotting/unknotting manipulation performed by a vision-guided system to demonstrate the usefulness of our approach.