Contour81 This is an Educational Game Mactivity's CD-ROM nr 10 advice: This application did run on a b/w 68030 processor under System 7.1, but the behaviour on a ColorScreen of a PowerMacintosh running System 7.1.2 was not satisfying. Our advice: use only on 68030 processors, or try with caution on a 68040 processor Contour81 is an application that creates contour maps and pictures from lists of three-dimensional data. A contour map is a two-dimensional picture of a surface defined by a set of data points. The points would usually be elevations of a physical location, such as a planned construction site. A survey crew would go to the site and essentially return with (among other things) a list of "points". Each one of these points would specify the elevation of some location at the site. Then, an engineer or draftsperson would have to plot the points and draw contour lines according to general rules of thumb. These contour lines would then represent locations at which the elevation was constant. A person could walk along the line and not move up or down with respect to a reference elevation at all. The site engineer can look at this contour map and calculate the volumes of various areas defined by the contour lines. In the case of site development, this tells him or her how much earth must be moved from one place to another in order to change the topography of the location into an acceptable form. A hydrologic engineer could look at the map and tell where flood areas would occur and the way that water would move around the site in a rainstorm. For example, water always seeks the lowest level as quickly as possible. Therefore it would flow perpendicular to the contour lines (the gradient), because that is the quickest way for it to change its elevation. Another type of contour map might be a scientist's plot of the electric potential (voltage) in an area of space. Then the contour lines would define equipotentials, a loose definition of these being lines that a charged particle could move on without changing its energy. In this example, if we draw lines perpendicular to the contour lines, these represent the electric field. In case you haven't guessed already, the process of drawing these contour maps by hand can be extremely tedious and time-consuming. Until the relatively recent advent of low-cost microcomputers, however, this was (and still is) the only way available to some technical people. This program provides the necessary mathematical and graphic power in an simple, low-cost application that adheres to the Macintosh(TM) User Interface Guidelines. We must assume that you are familiar with basic Macintosh operation and are knowledgeable about the meaning of your three-dimensional data and its analysis. You do not have to understand any of the mathematics behind the program if you do not wish to, but a full explanation of the process is provided for those who are interested. Please also note that the generation of hard copy from this program also requires the use of MacDraw(TM), AutoCAD(TM) or another program that can read and work with PICT or DXF(TM) files. Back to the Computer Games Index