Novel Techniques for Three-Dimensional Data Display

摘要

Three interactive programs for three-dimensional point or surface representation have been developed providing the user with a broad variety of easily controlled plotting options: projections, gridding, color, least squares data fitting, class distinctions, viewing perspective. These programs, written in FORTRAN for the CDC-7600, use DISSPLA for the three-dimensional graphics. The user may examine the plots in real time, simply change most of the program control parameters, producing new plots, iteratively. These may be edited in real time to yield a variety of graphical outputs. With these programs, the generation of stereo pairs for truly three-dimensional viewing is very simple. A second tool, termed sectioning, has also been implemented. Here, the user specifies a plane through which a set of points in three dimensions is viewed. Along the axis perpendicular to this plane, the points located in a series of user-specified sections are plotted as separate two-dimensional plots. These 2D views can be easily converted into transparent viewgraphs which can then be suspended from a simple wire frame. The assembly produces a very effective poor man's hologram of the original data set. A third program generates a combined surface/contour presentation as seen from any user viewpoint. Here again, under simple user control, a variety of options may be exercised interactively, producing three-dimensional plots with a surface sheet suspended above the corresponding contours drawn below.