GB1382657A - Computer-aided graphics system - Google Patents

Abstract

1382657 Digital processors CHEVRON RESEARCH CO 13 April 1972 [15 April 1971 19 May 1971] 17090/72 Heading G4A An axonometric layout of a pipe-line is provided as the output of a system which determines the layout and provides lists of materials, &c., required for the construction of the pipeline. The system employs a digital computer which is supplied with data which is in the form of a series of "workpoints". The workpoints, set up by the designer, identify elements which are required in the pipe-line. A workpoint defines a particular position in three dimensions relative to an associated workpoint and the workpoints are paired into overlapping sets so that the position of each is defined relative to the previous one of the series. In use a workpoint calls up data from a store to establish graphic functions dependent on, for example, a change of direction or the structural characteristics of the element to which the workpoint relates. The workpoints may also cause other information to be generated automatically; for example, if a valve is specified then automatically the mating flange is specified and consequent-dimensions are generated, no further workpoint being required. Other data fed to the computer relates to the techniques and materials to be used in the design of the pipe-line, taking account of the fluid to be handled and its temperature and pressure. Further data concerns material items numbers each related to a particular element. In operation the computer generates signals relating to the selection of elements to be used in forming the pipe-line and the true three dimensional co-ordinates of a series of workpoints related to the elements. Similar signals relating to other workpoints which can be implied from the series of workpoints (as in the case of the valve referred to above) are also generated. The system output comprises signals indicating the two-dimensional co-ordinates necessary to develop the axonometric layout as a visible display, and a list of materials and draughtsman's notes. The computer may operate to develop the best view of the pipe-line by determining the horizontal and vertical extent of the pipe-line as seen from four separate points, the view providing the largest extents being selected for display.