GB2169779A

GB2169779A - Depicting a three-dimensional object

Info

Publication number: GB2169779A
Application number: GB08600085A
Authority: GB
Inventors: Ari Elo
Original assignee: CADMATIC COMPUTER SERVICES KY
Current assignee: CADMATIC COMPUTER SERVICES KY
Priority date: 1985-01-14
Filing date: 1986-01-03
Publication date: 1986-07-16
Also published as: GB8600085D0; SE461062B; FI850147A0; FI850147L; FI72001B; DE3544789A1; SE8506040L; SE8506040D0; GB2169779B; JPS61190668A; FI72001C; NO855243L

Abstract

The apparatus depicts the three- dimensional object (1 Fig. 1) as plane projections (I, II, III) from three or more different directions (A,B,C) by means of coordinate data fed into the memory of a computer. The apparatus includes a picture screens 4',4'',4''' connected to a graphic processor 6, as well as control unit 5 for changing the location of the partial projection. A different projection of the object is depicted on each screen. Each screen is provided with its own image memory, each image memory storing a projection of the whole object in its respective plane. An altered location, of each component projection a,b,c can be depicted by means of its own picture screen 4',4'',4''' immediately on the basis of the data stored in the memory corresponding to the picture screen concerned. <IMAGE>

Description

SPECIFICATION Apparatus for depicting a three-dimensional object The present invention is concerned with an apparatus for depicting a three-dimensional object as plane projections from several directions by means of coordinate data fed into the memory of a computer, which said apparatus includes a picture screen connected to a separate graphic processor, which is in line connection with the computer, as well as control units for changing the location of the partial projection depicted of the object on the projection plane, whereby the picture screen consists of several portions, a different projection of the object being depicted in each portion.

The use of CAD systems has become common in various designing duties. In these systems, a threedimensional object is depicted on the image face of the picture screen by means of coordinate data fed into the memory of a computer. When necessary, different images can be produced by means of a plotter. When complicated volume models are dealt with by means of a computer, a major problem is the insufficient size of the picture screen. For an understanding of the geometry of a complicated object, it is necessary to see the object, as a rule, from at least three directions at the same time. By means of the present equipment, this is possible so that the picture screen of the display tube of the computer is divided into areas on which pictures are processed of the object from different directions.

If the object is large, panoraming and zooming must be used in the examination, both of which said operations require processing of the computer to such an extent that the operation becomes slow.

The apparatus in accordance with the present invention is characterized in that the portions of the picture screen consist of three or more separate picture screens, which are connected to a common graphic processor and each of which is provided with an image memory of its own, whereby, in each image memory, the data are stored on the projection of the whole object in the plane concerned, and that an altered location, in its own projection plane, of each component projection to be depicted of the object can be depicted by means of its own picture screen immediately by processing the data stored in the memory corresponding to the picture screen concerned, or in a part of the memory, by means of the graphic processor, without major processing of the computer. A three-dimensional object can be examined from three or even more different directions at the same time.

The image of each picture screen can be displaced on a larger background picture area without considerable and time-consuming computer processing. The image is already processed in advance in the image memory provided for each picture screen. The displacement of the image on each picture tube can be performed synchronously.

The apparatus in accordance with the invention can be used as a part in a larger system.

By means of the system, it is possible to perform, e.g., location and piping planning of complicated machinery rooms. Objects may be, e.g., the following: engine rooms of ships, off shore equipment, chemical factories, power plants, etc. In the system, the planning of the disposal of pipings takes place by constructing a data model which is fully equal to the traditional planning model. The geometry of individual pipes can be unpacked from the data model so as to prepare work drawings of pipe packages, isometry drawings, component drawings required by prefabrication of the pipes, and numeric control information.

The apparatus in accordance with the invention permits presentation of plane and sectional views of the data model on the picture screen.

The invention and its details will be described in more detail in the following with reference to the accompanying drawings, wherein Figure 1 is a schematical illustration of the depicting of an object by means of an apparatus in accordance with the invention, and Figure 2 illustrates one embodiment of the apparatus in accordance with the invention.

In Fig. 1, the object to be depicted is a space contained in a cube 1, which said space is examined from three different directions A, B and C as plane projections on three faces I, II and III of the cube 1. The parts that are being examined at one time are the portions a, b and c of three faces of the cube, which said portions can be imagined as three different projections of the small cube 2 placed inside the large cube 1. It should, however, be noticed that the cube 2 in itself is not depicted as a section. If there is something in the space of the cube 1 between the side of the cube 2 and the planes I, II or Ill, this something is projected in the planes I, II and Ill. The portions of faces are shown as three different projections, sections A-A, B-B and C-C in the planes I, II and Ill.Moreover, on the faces a, b and c, projections of a point 3 placed in the cube 2 are shown. If desired, the cube 2 may be displaced relative the cube 1, whereat the projections a, b and c of the cube 2 are displaced accordingly in the planes I, it and Ill.

A movement of the projection a in the plane I, e.g., to the left in Fig. 1, corresponds to an equally large movement of the projection c, likewise to the left, in the plane Ill. The plane II is perpendicular to the planes I and Ill, and it does not include the direction of movement of the said projections a and c, so that the projection b remains stationary in the plane 11.

On the contrary, if the projection c moves in the plane Ill, e.g., upwards, the projection b moves correspondingly upwards in the plane II. Thereat the projection a remains immobile.

Thus, all the projections always move in the same direction relative each other, provided that a component of the direction of movement concerned is included in the plane of the projection concerned.

Figure 2 shows a work station in which the invention is put into practice. The work station has three separate display tubes 4, 4" and 4"'. In each display tube, the parts a, b and c of the sections A-A, B-B and C-C are shown separately, which can therefore be seen simultaneously. In the memory of each picture screen, one of the sections A-A, B-B or C-C has been computed ready as a whole.

Thus, it has been possible to enlarge the image area to be processed at a time so that the image a, b, c shown by each picture tube is just a part of a larger background area, i.e.

the faces I, II and Ill of the cube 1. On the faces of the cube 1, it is possible to move almost in real time, and the displacement no longer requires processing. By means of a tablet 5, it is possible to control the locations of the faces a, b and c to be depicted on the faces I, II and Ill. By means of the same tablet, it is also possible to control the pointer or cursor seen on the face of the picture screen, moving synchronously in all the projections so that it is easy to point at a desired place in the space, i.e. at the point 3 shown in Fig. 1.

By means of the tablet, it is possible to point at a desired place in the space, i.e. at the point 3 shown in Fig. 1. In stead of a tablet, it is, of course, also possible to use, e.g., a "mouse" or the keyboard for controlling the coordinates. In Fig. 2, the graphic processor 6 with its memory, connected to the apparatus, is illustrated schematically only.

A work station in accordance with the invention can be used as a part of a larger system. The system includes a basic program which takes care of all the data control required by the system and permits connections with other computer systems. The data of the equipment to be located in the space to be planned are fed into the system. The input operations can be decentralized, and they may be carried out by using the same terminals as are used for :he oL-pJ't.

A second sub-program belonging to the system prepares a model of the object that is being planned, which said model can be visualized by looking at several sections A-A, B-B and C-C taken of the same object. On the sections, only the direction of viewing, location of section plane, depth, and the scale are given. The delta model produced is stored, by the intermediate of shebas, PrJS8ZmT r the common database, either to als f adåitions to be made later or to be ptoauced as an output in the form of drawings as uilell as as part lists. Depending on the capacity of the central computer, this program can be run either in it or in a separate central unit associated with a smaller disc storage of its own and having a sufficiently high processing speed.

The system may further include a program for the preparation of part lists as well as a drawing program, which produces the output in the form of bi-dimensional drawings as plane and sectional views.

The system can be connected to so-called general CAD systems.

Claims

1. Apparatus for depicting a three-dimensional object (1) as plane projections from several different directions (A,B,C) by means of coordinate data fed into the memory of a computer, which said apparatus includes a picture screen connected to a separate graphic processor (6), which is in line connection with the computer, as well as control units (5) for changing the location of the partial projection (a,b,c) depicted of the object on the projection plane (1,11,111), whereby the picture screen consists of several portions (4',4",4"'), a different projection of the object being depicted in each portion, characterized in that the portions of the picture screen consist of three or more separate picture screens (4',4",4"'), which are connected to a common graphic processor (6) and each of which is provided with an image memory of its own, whereby, in each image memory, the data are stored on the projection of the whole object in the plane (1,11, Ill) concerned, and that an altered location, in its own projection plane (1,11,111), of each component projection (a,b,c) to be depicted of the object can be depicted by means of its own picture screen (4',4",4"') immediately by processing the data stored in the memory corresponding to the picture screen concerned, or in a part of the memory, by means of the graphic processor, without major processing of the computer.

2. Apparatus as claimed in claim 1, characterized in that the object (1) to be depicted is depicted from three directions (A, B, C) perpendicular to each other.

3. Apparatus as claimed in claim 1 or 2, which is provided with means (5) for pointing at a certain point (3) in the projection shown in the picture screen, characterized in that the location of the pointer is changed synchronously in each projection (a, b, c) to the point corresponding to the location of the point (3).

4. Apparatus for depicting a three-dimensional object, the apparatus comprising computer means for deriving, from data representing the configuration of the object, image data representing the image of the object when viewed from respective direct;cns, and a plu paltry of separately-addressable memories each for storing the image data associated with a respective viewing direction, the apparatus further comprising means for graphically displaying the image data.

5. Apparatus as claimed in claim 4, wherein said displaying means comprises separate screens each for graphically displaying the image data of a respective one of the memories.