CROSEC, A Fortran IV-APT Program to Give Orthographic, Section, and Definable Perspective Views of a Planar-Curved Surface

A Fortran IV program, CROSEC (MOD 2.0) has been written to operate in the environment of NRL's APT system on the CDC 3800 Computer. This program enables the part programmer for numerically controlled tooling systems to obtain plots of the intersections between a specially designated plane (called the HOPE plane) and certain defined forms in his APT part program. The forms with which intersections can be obtained are lines, planes, circles, cylinders, and spheres. When the HOPE plane corresponds to a coordinate plane (XY, XZ, and YZ), an orthographic projection pattern is obtained corresponding to engineering drawings's top, front, and end views, respectively. When the HOPE plane cuts through the volume of the part surface and the plotting limits are the part's minimum and maximum dimensions, a true view of the cross section is obtained. When the HOPE plane lies outside the volume of the part and is skewed with respect to the coordinate planes, an abstract pattern is obtained because the planes and cylinders are not bounded. Such an abstract pattern, when composed only of plane intersections, through an unprogrammed process, can be interpreted as a perspective view of the part. When the plotting limits extend beyond the dimensions of the part and the HOPE plane cuts its volume, a combination of true view and interpretable perspective view is obtained. (Author)