A Sangaku Revived

In this paper we give an account on our mathematical and visual explorations inspired by a sangaku. First we introduce sangakus – traditional Japanese mathematical tablets. Then we give four examples of our static contemporary variants. Finally, we discuss in detail how a fifth sangaku led us to simulate the growth of water lilies, as a means of visualizing the problem. This approach lead to the mathematical field of circle packing, and made it possible to experience the visually intriguing process with different settings of the algorithm

Interactive 3D Simulation of Escher-like Impossible Worlds

figures and impossible worlds. Many of his works illustrate mathematical and geometrical concepts such as perspective and limits. Works by Escher have motivated scientists over the years to discover the mathematical foundations of his work, ultimately leading to applications that are able to model and render scenes similar to the ones created by Escher. Presented is an application that is capable of displaying a special class of impossible worlds that have been created by the artist. The software displays worlds that appear physically correct, but are connected in an impossible manner, similar to Escher’s Another World II or Relativity. Portal rendering is employed to create real-time interactive visualizations of such scenes, which can be freely explored by the user

A Closer Look at Jamnitzer's Polyhedra

The Renaissance artist Wentzel Jamnitzer designed series of intriguing polyhedra in perspective in his book “Perspectiva Corporum Regularium”. In this paper we investigate the possible principles of the construction of the polyhedra and create 3D computer models of them. Comparing those to the originals, we get an idea of how successful he was in drawing the complex structures by imagination. Furthermore, we analyse Jamnitzer's use of linear perspective, an important key in creating such drawings

CharToon 2.1 extensions : expression repertoire and lip sync

CharToon is a modular system to design and animate 21/2D faces and other graphic al objects. This report contains the extensions made for version 2.1, effecting only the Animation Editor module. The new features allow the re-usage of a reper toire of expression snapshots and animations and automatic generation of lip-syn c from phoneme and/or viseme sequences

Measuring Behavior using Motion Capture

Motion capture systems, using optical, magnetic or mechanical sensors are now widely used to record\ud human motion. Motion capture provides us with precise measurements of human motion at a very high\ud recording frequency and accuracy, resulting in a massive amount of movement data on several joints of the\ud body or markers of the face. But how do we make sure that we record the right things? And how can we\ud correctly interpret the recorded data?\ud In this multi-disciplinary symposium, speakers from the field of biomechanics, computer animation, human\ud computer interaction and behavior science come together to discus their methods to both record motion and\ud to extract useful properties from the data. In these fields, the construction of human movement models from\ud motion capture data is the focal point, although the application of such models differs per field. Such\ud models can be used to generate and evaluate highly adaptable and believable animation on virtual\ud characters in computer animation, to explore the details of gesture interaction in Human Computer\ud Interaction applications, to identify patterns related to affective states or to find biomechanical properties of\ud human movement

Dialogues with a talking face for web-based services and transactions

In this paper we discuss our research on interactions in a virtual theatre that has been built using VRML and therefore can be accessed through Web pages. In\ud the virtual environment we employ several agents. The virtual theatre allows navigation input through keyboard and mouse, but there is also a navigation\ud agent which listens to typed input and spoken commands. Feedback of the system is given using speech synthesis. We also have an information agent which allows a natural language dialogue with the system where the input is keyboard-driven and the output is both with tables as with template driven natural language generation. In development are several talking faces for the different agents in the virtual world. At this moment an avatar with a cartoon-like talking face driven by a text-to-speech synthesizer can provide users with information about performances in the theatre