Path: utzoo!utgpu!jarvis.csri.toronto.edu!qucis!bradshaw From: bradshaw@qucis.queensu.CA (Tom Bradshaw) Newsgroups: comp.graphics Subject: Looking for Scientific Visualization tools Keywords: SPARC Visualization tools Message-ID: <305@qusunm.queensu.CA> Date: 9 Nov 89 17:11:03 GMT Organization: Queen's University, Kingston, Ontario, Canada Lines: 84 The following is a note I am forwarding for a friend. Please reply to GALLERC%ALCANKTN.bitnet@ugw.utcs.utoronto.ca . They are looking for Visualization tools for machines like the SPARC station. ------------------------------------------------------------------------ The following is a description of the functions we are searching for in a "Scientific Visualization" tool. Primarily we wish to be able to take scientific data generated by, for example, a finite element analysis program and allow the user to interact with it. (i.e. the data could be regular or irregular gridded nodes.) The display would consist of polygonal data and the user would be able to orient a cutting plane through objects. The area outside of the cutting plane can be rendered in wire frame but where alpha blending is available we would prefer that the area be optionally displayed as transparent or semi-transparent. The data will have additional scalar information associated with it such as stress, temperature, turbulence or field intensity inside the object. This scalar data should be representable by different colours. It should be possible to animate both the object itself as well as displacements and the scalar values at each node in real time. (i.e. time steps of data will be pre-computed and the visualization tool would be asked to interpolate between these.) One feature we are very interested in in the capability to interactively select and display iso-contour surfaces. An iso-contour surface is a surface inside the data where all of the stresses or field strengths are the same. Some examples are attached (Figures 1 & 2). Other features such as ability to display more than one model (object) at a time (for comparison purposes), legends for stress (colour) values, titles and notes, as well as hardcopy capability for interactively selected views. It would be useful to be able to set the cutting plane at a precise location in the object in order to examine specific 2D planes in isolation (Figure 4). Another area of interest is the visualization of flow fields (vector data). Here animated particle as well as front movement is required. Changing the vector's colour, width, etc., depending on other scalar properties at that point, should be possible. Description of Attached Figures: The figures were produced on a Tektronics 4693A thermal wax printer. They are representative of the type of thing we have in mind but are not as "pleasing" as the original workstation version, particularly with respect to the appearence of the transparent regions. Figure 1. Here we show 2 models (2 graphical objects slightly displaced) whose outer surfaces have been rendered in wire frame but inner surfaces (electric field values) are shown as 3D iso-contour lines. The cutting plane is visible but not in use (offset from data). The user is able to interactively and in real time select which inner surface is being displayed. Figure 2. Same data set as in figure 1. Here the cutting plane is in use. Object parts behind the plane are rendered as a shaded silver material, with the cut plane showing scalar colour values. In front of the cutting plane the objects are wire frame and translucent iso-contour surfaces are displayed. Figure 3. Same as figure 2 except that in the upper object transparency rather than wire frame is used in front of the cutting plane. In the lower object the parts behind the cutting plane are rendered to show the scalar values at the exposed surfaces. In both objects the iso-contour surfaces are shown in front of the cutting plane. Figure 4. 2D image of a single plane of interest, in this case a slice near the bottom of the lower object seen in figures 1,2 & 3.