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Item HyperStreamball Visualization for Symmetric Second Order Tensor Fields(The Eurographics Association, 2006) Liu, J.; Turner, M.; Hewitt, W. T.; Perrin, J. S.; Louise M. Lever and Mary McDerbyThis paper proposes a new 3D tensor glyph called a hyperstreamball that extends streamball visualization used within fluid flow fields to applications within second order tensor fields. The hyperstreamball is a hybrid of the ellipsoid, hyperstreamline and hyperstreamsurface. With the proposed system a user can easily interactively change the visualization. First, we define the distance of the influence function which contributes a potential field that can be designed to highlight the three eigenvectors and eigenvalues of a real symmetric tensor at any sample point. Second, we discuss the choice of source position and how the user can control the parameter mapping between the field data and the implicit function. Finally, we test our results using both synthetic and real data that shows the hyperstreamball's two main advantages: one is that hyperstreamballs blend and split with each other automatically depending on the tensor data, and the other advantage is that the user can achieve both discrete and continuous representation of the data based on a single geometrical description.Item A Lemon is not a Monstar: Visualization of Singularities of Symmetric Second Rank Tensor Fields in the Plane(The Eurographics Association, 2008) Liu, J.; Hewitt, W. T.; Lionheart, W. R. B.; Montaldi, J.; Turner, M.; Ik Soo Lim and Wen TangIn the visualization of the topology of second rank symmetric tensor fields in the plane one can extract some key points (degenerate points), and curves (separatrices) that characterize the qualitative behaviour of the whole tensor field. This can provide a global structure of the whole tensor field, and effectively reduce the complexity of the original data. To construct this global structure it is important to classify those degenerate points accurately. However, in existing visualization techniques, a degenerate point is only classified into two types: trisector and wedge types. In this work, we will apply the theory from the analysis of binary differential equations and demonstrate that, topologically, a simple degenerate point should be classified into three types: star (trisector), lemon and monstar. The later two types were mistakenly regarded as a single type in the existing visualization techniques.Item Visual Analysis of Packing Process for 3D Container(The Eurographics Association, 2006) Yue, Y.; Middleton, M.; Liu, J.; Louise M. Lever and Mary McDerbyThe cutting and packing problem has been encountered in many industrial sectors, and become a research focus in operations research. Because of its nature, it is a commendable goal to visualise the process of cutting and packing for analysis and validation of the algorithms. This is even more desirable when working in a 3- dimensional environment. There have been some visualisation packages for which the working algorithms are hidden behind the screen. Furthermore, their effectiveness and flexibility are limited in some sense. This research presents a visual analysis tool for 3-dimensional container loading. A new loading and display algorithm is devised to suit requirements for container loading. Test results are given with recommendations for further effort.