Willem C. de Leeuw and Jarke J. van Wijk. A probe for local flow field visualization. In R.D. Bergeron G.M. Nielson, editor, IEEE Visualization '93, pages 39--45, Los Alamitos, CA, 1993. IEEE Computer Society Press.  Home/Search   Document Not in Database   Summary   Related Articles   Check

....and interesting to our own research and expertise are those by [19] on vector and tensor field visualization. Research on methods for visualizing 2 order tensor fields is actively being carried out by a very small group of people: Hesselink [7, 8, 18, 21] in the US, Post [19] and van Wijk [6] in the Netherlands, and Hagen [4, 14] in Germany. Yet scientists and engineers have to deal with these type of data sets almost on a daily basis. This research presents intuitive, deformation based tensor field visualization techniques to complement the limited set of current techniques. ....

....presented in a 3 x 3 panel layout, one for each of the 9 scalar components. The main drawback with this approach is the burden placed on the user to mentally integrate and interpret the 9 separate maps. Tensor glyphs This method relies on judicious design and placement of discrete tensor glyphs [12, 6, 26, 24]. Tensor glyphs encode tensor information from discrete locations within the field onto a geometric object. For example, mapping the three eigenvectors as principal axes of an ellipsoid, or including additional derived information such as shear, convergence divergence, curvature onto a flow probe. ....

Willem C. de Leeuw and Jarke J. van Wijk. A probe for local flow field visualization. In Proceedings of Visualization 93, pages 39--45. IEEE Computer Society Press, October 1993.

....functions such as understanding flow at a point, on a surface, or in a field. For in depth investigation of a particular flow area, point probes can be used. A simple velocity arrow is often used for this purpose. An expansion on this idea is a flow probe tool developed by de Leeuw and van Wijk[dLvW93] The tool is a complex icon with separate elements to display velocity, curvature, acceleration, rotation, shear, and convergence. Two dimensional flow visualization can be used in three dimensional flow to view cutting planes, body surfaces, or isosurfaces. A cutting plane can be swept through ....

Willem C. de Leeuw and Jarke J. van Wijk. A probe for local flow field visualization. In Gregory M. Nielson and Dan Bergeron, editors, IEEE Visualization '93, pages 39--45, Los Alamitos, California, October 1993. IEEE, IEEE Computer Society Press.

....matrix at fixed points is used for visualization. Globus et at. 8] developed a tool to identify topological elements within data which is specified on grids. Rumpf and Happe [24] as well as Post et al. 22] use icons for visualizing local flow characteristics, whereas de Leeuw and van Wijk [7] use glyphs to do so. More literature is reviewed by Levit [12] and Asimov [5] We now propose to combine both approaches: do analysis of flow topology first for researching the most important structures like fixed points. Next, use the results gained for visualization (location type of fixed ....

W. de Leeuw and J. van Wijk. A probe for local flow field visualization. In Proc. of IEEE Visualization '93, pages 39--45, 1993.

....higher level features are not well visualized due to glyph sparseness (or density) The technique is characterized by vector dimensionality, point domain, and elementary locality. Wind barbs, uncertainty glyphs [18] and other specialized glyphs are extensions of this basic idea. Flow probes [5] and tensor probes [17] are tools that present a complex iconic representation at single or multiple probe points in the field. Such glyphs can span a large feature space since the probe focuses on a single point or few points in the field. For example, Wijk et al. 17] demonstrate a tensor probe ....

Willem C. de Leeuw and Jarke J. van Wijk. A probe for local flow field visualization. In Proceedings of Visualization93, pages 39--45. IEEE Computer Society Press, October 1993.

....mapping data values to some of its graphical attributes. An interactively positioned glyph adapts its appearance according to the underlying data. Variables can be mapped to the length, shape, angle, color and transparency of the glyph. Examples of this kind of visualization are given in [13] and [14]. Icons Another visualization method uses icons as basic primitives. An icon is a generalization of a single pixel to higher dimensions having multiple perceivable features and attributes. The fact that shape and color are perceptually separable features is used for the display of color icons. ....

....example scalar) data is displayed in n space. The derived data has not to be a scalar, but can be of dimension m itself. The directional information at each point in n space may be projected to an m dimensional data object that describes some local features of the system. An example is given by [14], who use a glyph for displaying topological information of the flow such as convergence, shear, vorticity and curvature. 2. A direct global visualization of the flow can be done by starting short integral curves, so called trajectories, which follow the flow, at the nodes of an n dimensional ....

W. C. de Leeuw, J. J. van Wijk, A Probe for Local Flow Field Visualization, IEEE Visualization '93 Proceedings, pages 39-- 45, 1993.

....to volume render both a vector and a scalar field in the same image. More recently, Max et al. used a volumetric equivalent of stream lines to volume render vector fields[MBC93] Leeuw and van Wijk map scalar, vector and tensor values to a 3 D probe for interactive local flow field visualization[dLvW93] Van Wijk also used implicit surface representation to construct implicit stream surfaces of flow fields[vW93] Crawfis and Max extended the splatting technique to include textures for vector field visualization [CM93] Cabral and Leedom introduced a novel technique which uses linear and ....

Willem C. de Leeuw and Jarke J. van Wijk. A probe for local flow field visualization. In Proceedings: Visualization '93, pages 39 -- 45. IEEE Computer Society, 1993.

....[14] The work by van Leeuw et al. takes this method one step further by using visual probes that consist of a set of geometric primitives. Multiple characteristics of a small area in a flow field transform the geometric primitives in the probe to visualize velocity and local change of velocity [6]. Although these visual probes provide excellent means for exploring local properties of a dataset, they are often used for localized visualization only, and not for obtaining quantitative measurements. The work by Brady et al. shows a CAVE application for the visualization of biomedical images ....

Willem C. de Leeuw and Jarke J. van Wijk. A probe for local flow field visualization. In R.D. Bergeron G.M. Nielson, editor, IEEE Visualization '93, pages 39--45, Los Alamitos, CA, 1993. IEEE Computer Society Press.

....The coordinates correspond to the amount of linear, planar and spherical anisotropy in the tensor. The lack of clustering suggests considerable partial voluming is taking place within the volume. 2. 2 Previous Work Traditional methods for visualizing tensor data include brush strokes [8] glyphs [2, 5, 10], ellipsoids [6, 13, 14] stream polygons [12] and hyperstreamlines [3, 4] Using a 2D approach, Laidlaw [8] uses brush strokes to represent the diffusion tensor data through various stroke shape, color and texture cues. This method works well in 2D, but it is not clear how it can be effectively ....

W.C. de Leeuw and J.J. van Wijk. A probe for local flow field visualization. In IEEE Visualization 93 Proceedings, pages 39--45, 1993.

....3D LIC volume interactively during rasterization. 1 Introduction 3D flow visualization is an important topic of research. A number of different techniques have been evolved to visualize vector fields. Traditionally, vector data are visualized by simple arrow plots. More advanced methods use icons [6] that show some more parameters of the field. However, these icons are sometimes difficult to interpret. Sophisticated approaches to depict properties of vector fields include methods like stream lines, stream surfaces [10] volume flows [16] and various particle tracing techniques. These ....

W. C. de Leeuw and J. J. van Wijk. A Probe for Local Flow Field Visualization. In G. M. Nielson and Bergeron D., editors, Visualization '93, pages 39--45, Los Alamitos, CA, 1993. IEEE Computer Society, IEEE Computer Society Press.

....systems only provide instantaneous visualization of the flow data. For example, instantaneous streamlines, isosurfaces, and slicing planes. Several effective techniques were recently developed for interactive interrogation of instantaneous flow fields. Some of these techniques are described in [6,8,11]. To date, there are very few particle tracing systems that can generate streaklines using a large number of time steps from unsteady flow fields. Two of these are Virtual Wind Tunnel (VWT) 3] and pV3 [7] VWT provides interactive visualization of particle traces in a virtual environment using a ....

de Leeuw, W. and van Wijk, J., A Probe for Local Flow Field Visualization, in: G. Nielson and D. Bergeron, eds., Proceedings of Visualization '93, San Jose, California, October 1993, pp. 39-45.

....local flow characteristics near fixed points of the system. Overviews of work in this area are given by Levit in 1992 [11] and Asimov et al. in 1995 [6] Several other approaches to flow visualization are related to the visualization of vector field topology. The visualization of local properties [7, 13, 14, 16], for example, is an extension to the approach of visually encoding the Jacobian matrix. The visualization of tensor field topology [8] is also strongly related to this topic. 2 Visualizing the vicinity of critical points In the following sections we describe two techniques to visualize the ....

W. C. de Leeuw and J. J. van Wijk. A probe for local flow field visualization. In Proceedings of IEEE Visualization '93, pages 39--45, 1993.

....visualization extent (second column) We have not seen any visualization methods designed for presenting uncertainty information for vector or tensor data. However, some existing vector and tensor visualization methods can be modified to include uncertainty information. For example, tensor probes [dLvW93] with discrete visualization extents can be easily modified to incorporate uncertainty information. For continuous visualization extents, line integral convolution (LIC) FC95] can use the uncertainty information to modulate the texture. Likewise, adding more variables into existing flow ....

Willem C. de Leeuw and Jarke J. van Wijk. A probe for local flow field visualization. In Proceedings of Visualization 93, pages 39--45. IEEE Computer Society Press, October 1993.

....the following sections four classes of techniques in this field of visualization are presented. As one approach (section 2.1) visualization is intended to represent local properties at some point (state) of the system. Glyphs are a prominent example for visualization techniques of this kind [1] 6][7][12] Another approach (section 2.2) is to represent the topology of behavior of a dynamical system. The visualization of characteristic subsets, e.g. attractors, helps to understand the global behavior induced by the corresponding system [3] Other techniques try to directly visualize the ....

....2, no. 4, 1993, pp. H. Loffelmann, E. Groller, R. Wegenkittl, W. Purgathofer 3 divergence. A vortex or a point near an obstacle may be such a point of special interest. Thus visualization techniques were developed that help to investigate these local flow properties. Fig. 2. de Leeuw, van Wijk [7]: a glyph visualizing local properties De Leeuw and van Wijk use a glyph to visualize local flow behavior [7] They decompose the velocity gradient tensor into components parallel and perpendicular to the flow. This is done after the system is transformed it into a local coordinate system. ....

[Article contains additional citation context not shown here]

W. C. de Leeuw and J. J. van Wijk. A probe for local flow field visualization. In Proceedings Visualization '93, pages 117--123, October 1994.

....visualization of three dimensional (3 D) vector fields, such as electromagnetic fields, has been accomplished with a number of techniques [2] The simplest of these is to place an icon within the data field to express local characteristics of the field. The icon can be an arrow plot or probe [4]. An arrow is a line segment whose length is proportional to the magnitude of the vector and whose orientation depicts the vector s direction. A probe is a set of graphic primitives expressing a number of local characteristics such as curvature and torsion. Global characteristics of the 3 D vector ....

W. de Leeuw and J. van Wijk. A probe for local flow field visualization. In IEEE Visualization '93 Conference Proceedings, pages 39--45, 1993.

....workstation. Some alternative representations are shown in Figure 2. The simpler symbols are built of simple line and point primitives only. Usually these primitives are colored, but no shading is applied. A straight forward extensions of a simple arrow has been proposed by de Leeuw and van Wijk [8]. Their vector field probe or icon not only indicates field magnitude and direction, but also properties obtained from a first order field expansion. At a particular point all first order derivatives are computed, yielding the field s Jacobian matrix. This matrix is decomposed into characteristic ....

W.C. de Leeuw, J.J. van Wijk, A probe for local flow field visualization, Proceedings of Visualization '93, Nielson and Bergeron, Eds., IEEE Computer Society Press, 1993, 39-45.

....data values to some of its graphical attributes. An interactive positioned glyph adapts its appearance according to the underlying data. Variables can be mapped to the length, shape, angle, color and transparency of the glyph. Examples for a this kind of visualization are given in [Kerl90] and [LeWi93]. Icons Another visualization method uses icons as basic primitives. An icon is a generalization of a single pixel to higher dimensions having multiple perceivable features and attributes. The fact that shape and color are perceptually separable features is used for the displaying of color Icons. ....

....(for example scalar) data is displayed in n space. The derived data has not to be a scalar, but can be of dimension m itself, but now the directional information at each point in n space is projected to an m dimensional data that describes some local features of the system. An example is given by [LeWi93], who use a glyph for displaying topological information of the flow such as convergence, shear, vorticity and curvature. 2. A direct global visualization of the flow can be done by starting at an n dimensional regular grid short integral curves, so called trajectories, which follow the flow. The ....

W. C. de Leeuw, J. J. van Wijk, A Probe for Local Flow Field Visualization, Proceedings of IEEE Visualization '93, Boston, 1993, pp. 39--45

....to generate time surfaces is speed, making it difficult to obtain real time animations. We classify these techniques as of the second kind, as they try to convey global information of the vector field. Some other techniques also try to visualize tensor data. For instance, de Leeuw and van Wijk [dLvW93] developed an interesting gadget for local flow field visualization. Their method basically transforms the vector field to a local coordinate frame, then decomposes the tensor into information parallel to the flow (acceleration, shear, curvature) and perpendicular to the flow (torsion, ....

W. C. de Leeuw and J. J. van Wijk. A probe for local flow field visualization. In Proc. Visualization '93, pages 39--45, 1993.

....visualized. Some attempts into this direction are illuminated stream lines [19] and volume rendered 3D flow [7] In addition of the visualization of characteristic elements and direct visualization, a third class of techniques deals with the representation of local properties [12] Glyphs [6] represent certain quantities derived from the Jacobian matrix (local lineariztion of the flow) as, e.g. acceleration, rotation, or divergence. Another approach [17] transforms a polygon positioned perpendicular to a trajectory to represent local information. In this paper we present a technique ....

W. C. de Leeuw and J. J. van Wijk. A probe for local flow field visualization. In Proceedings of IEEE Visualization '93, pages 117--123, October 1994.

.... have been used to represent univariate data [Tuk84, Tuf83] Different types of glyphs such as stars, Chernoff faces, boxes, profiles, Kleiner Hartigan tress and Andrew s plots have been used to represent multivariate data [CBB91] Glyphs for representing vector and tensor fields are shown in [dLvW93] Texture mapping has been used in scientific visualization [vW91] Displacement mapping and bump mapping are also standard techniques in computer graphics. In addition to the techniques mentioned above, most of the work in visualization of uncertainty has been in the field of Geographic ....

Willem C. de Leeuw and Jarke J. van Wijk. A probe for local flow field visualization. In Proceedings of Visualization 93, pages 39-- 45. IEEE Computer Society Press, October 1993.

....the user to release particles at interesting locations. Multivariate techniques generally use some kind of glyph to encode different variables as features of the glyph [17] The size of most glyphs is such that they are useful for scattered data, or gridded data that has been sparsely sampled [21]. However, the Pickett icon has been used effectively to portray a collection of gridded variables, producing various texture patterns across the image [51] Interactive widgets, such as small cutting planes, particle emitters or rakes, are used, either alone or in conjunction with these various ....

Willem C. de Leeuw and Jarke J. van Wijk. A probe for local flow field visualization. In Proceedings of Visualization '93, pages 39--45, 1993.

No context found.

Willem C. de Leeuw and Jarke J. van Wijk. A probe for local flow field visualization. In R.D. Bergeron G.M. Nielson, editor, IEEE Visualization '93, pages 39--45, Los Alamitos, CA, 1993. IEEE Computer Society Press.

No context found.

Willem C. de Leeuw and Jarke J. van Wijk. A probe for local flow field visualization. In Proceedings of Visualization 93, pages 39--45. IEEE Computer Society Press, October 1993.

No context found.

Willem de Leeuw and Jarke van Wijk. A probe for local flow field visualization. In Nielson and Bergeron, 77 pages 39--45.

No context found.

Willem C. de Leeuw and Jarke J. van Wijk. A probe for local flow field visualization. In Proceedings: Visualization '93, pages 39 -- 45. IEEE Computer Society, 1993.

No context found.

W. C. de Leeuw and J. J. van Wijk, "A probe for local flow field visualization," Proceedings IEEE Visualization '93 , pp. 117--123, October 1993.

No context found.

W. C. de Leeuw and J. J. van Wijk, "A probe for local flow field visualization," Proceedings IEEE Visualization '93 , pp. 117--123, October 1993.

No context found.

Willem C. de Leeuw and Jarke J. van Wijk. A probe for local flow field visualization. In Proceedings of Visualization 93, pages 39--45. IEEE Computer Society Press, October 1993.

Online articles have much greater impact   More about CiteSeer.IST   Add search form to your site   Submit documents   Feedback  

CiteSeer.IST - Copyright Penn State and NEC