3D object graphics display device, 3D object graphics display method, and manipulator for 3D object graphics display

• US 5,818,420 A
• Filed: 10/18/1996
• Issued: 10/06/1998
• Est. Priority Date: 07/31/1996
• Status: Expired due to Fees

• Current Assignee: NHK Engineering Services Incorporated, Nippon Hoso Kyokai, Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Original Assignee: NHK Engineering Services Incorporated, Nippon Hoso Kyokai, Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: Noguchi, Hideo, Fujiwara, Masao, Ninomiya, Yuichi, Hontani, Kunihiko, Enami, Kazumasa, Kato, Tadoru, Mitsumine, Hideki, Inoue, Seiki
• Primary Examiner(s): Saras, Steven
• Assistant Examiner(s): Kovalick, Vincent E.
• Application Number:
  US08/733,599
• Time in Patent Office: 718 Days
• Field of Search: 345/31, 345/156, 345/158, 345/202, 345/173, 345/161, 345/167, 345/126, 345/133, 395/119, 395/121, 395/125, 395/130, 395/133-139
• US Class Current: 345/156
• CPC Class Codes: G06T 17/00 Three dimensional [3D] modelling, e.g. data description of 3D objects

Abstract

A 3D object graphics display device for storing information about 3D objects such as works of art or buildings, and for displaying them on a 2D display. The "3D shape data" and "texture data" of a 3D object is stored in a memory in advance. When an operator operates a manipulator, a 2D image is generated, which would be acquired when the 3D object is seen from a viewpoint indicated by the manipulator, by using the 3D shape data and the texture data in every 1/60 sec or less interval (that is, a minimum display interval of the display device). The 2D image is shown on the display, giving the operator a virtual-reality-like feeling as if he was actually holding the 3D object.

Claims

1. A 3D (three-dimensional) object graphics display device for displaying a 2D (two-dimensional) graphics image by performing image processing on prestored 3D object image data, said 3D objects graphics display device comprising:

a manipulator for outputting position information, said manipulator having at least two degrees of freedom and allowing free rotation; and

calculation processing means for generating, when said manipulator indicates a reference position, a 2D image of a 3D object seen from a particular viewpoint, and for generating, when said manipulator points to a position apart from said reference position by a displacement amount, a 2D image of said 3D object seen from a viewpoint shifted by an amount corresponding to said displacement amount, said generating being carried out on the basis of 3D shape data and texture data of said 3D object, which are prestored in a storage as said 3D object image data, said calculation processing means iterating said image generating at a minimum display interval of every 1/60 of a second and completing a 2D display within 1/60 of a second from a beginning of said image generating.

2. The 3D object graphics display device as claimed in claim 1, wherein said manipulator comprises:

a fixed portion;

a positioning operation portion mounted on said fixed portion, said positioning operation portion having two or more degrees of freedom, and being displaced by an external force; and

two or more converters each provided in correspondence with each one of said degrees of freedom, for converting displacement amounts on respective axes corresponding to said degrees of freedom into displacement amounts in terms of length or angle, and for outputting said displacement amounts in a form of electric signals.

3. A 3D (three-dimensional) object graphics display method for displaying an image on a 2D (two-dimensional) display by performing image processing on image data prestored in a storage, said 3D object graphics display method comprising the steps of:

generating, when a manipulator indicates a reference position, a 2D image of a 3D object seen from a particular viewpoint, and for generating, when said manipulator points to a position apart from said reference position by a displacement amount, a 2D image of said 3D object seen from a viewpoint shifted by an amount corresponding to said displacement amount, said generating being carried out by using 3D shape data and texture data of said 3D object, which are prestored in said storage as said 3D object image data, said manipulator including a positioning operation portion mounted on a fixed portion, and two or more converters, said positioning operation portion having two or more degrees of freedom, and being displaced by an external force, and said two or more converters being each provided in correspondence with each one of said degrees of freedom, for converting displacement amounts on respective axes corresponding to said degrees of freedom into displacement amounts in terms of length or angle to be output in a form of electric signals;

iterating said image generating in response to position information of said positioning operation portion at every 1/60 sec; and

completing display on said 2D display within 1/60 sec from a beginning of said image generating.

4. A manipulator including a positioning operation portion which is mounted on a fixed portion, is displaced by external force, and has two or more degrees of freedom, said manipulator further including two or more converters each provided in correspondence with each one of said degrees of freedom, for converting displacement amounts on respective axes corresponding to said degrees of freedom into displacement amounts in terms of length or angle, and for outputting said displacement amounts in a form of electric signals, said manipulator comprising:

comparing means for comparing a predetermined range with a position indicated by said positioning operation portion, said predetermined range being set in advance within a physically operable range of said positioning operation portion, and said position indicated by said positioning operation portion being calculated from said electric signals representative of said displacement amounts;

a plurality of electromagnetic brakes for limiting an operable range of said positioning operation portion to within said predetermined range in response to an output of said comparing means;

external force detecting means for detecting a direction of said external force exerted on said positioning operation portion when said electromagnetic brakes are locked; and

a electromagnetic brake controller for electrically locking said electromagnetic brakes at least on a border of said predetermined range, and for releasing the lock of said electromagnetic brakes when said external force exerted on said positioning operation portion is directed towards an inside of said predetermined range.

5. The manipulator as claimed in claim 4, wherein said positioning operation portion is connected to said converters, and is coupled with said electromagnetic brakes with a backlash being provided at coupling portions, said backlash being equal to or greater than resolution of said converters.

6. The manipulator as claimed in claim 5, wherein said electromagnetic brake controller comprises control means for causing said electromagnetic brakes to generate at least a fixed braking force over an entire region of said predetermined range.

7. The manipulator as claimed in claim 6, wherein said positioning operation portion comprises a spherical shape which rotates about a center of a sphere of 10-30 cm in diameter.

8. The manipulator as claimed in claim 5, wherein said electromagnetic brake controller comprises control means for causing said electromagnetic brakes to generate braking force in inverse proportion to an acceleration of said positioning operation portion, said acceleration being calculated from said electric signals representing displacement amounts in terms of a length or angle within the entire region of said predetermined range.

9. The manipulator as claimed in claim 8, wherein said positioning operation portion comprises a spherical shape which rotates about a center of a sphere of 10-30 cm in diameter.

10. The manipulator as claimed in claim 4, wherein said electromagnetic brake controller comprises control means for increasing braking force of said electromagnetic brakes as the position indicated by said positioning operation portion approaches said border of said predetermined range, within a fixed range near said border, and for locking said electromagnetic brakes electrically on said border of said predetermined range.

11. The manipulator as claimed in claim 10, wherein said electromagnetic brake controller comprises control means for causing said electromagnetic brakes to generate at least a fixed braking force over an entire region of said predetermined range.

12. The manipulator as claimed in claim 11, wherein said positioning operation portion comprises a spherical shape which rotates about a center of a sphere of 10-30 cm in diameter.

13. The manipulator as claimed in claim 10, wherein said electromagnetic brake controller comprises control means for causing said electromagnetic brakes to generate braking force in inverse proportion to an acceleration of said positioning operation portion, said acceleration being calculated from said electric signals representing displacement amounts in terms of a length or angle within the entire region of said predetermined range.

14. The manipulator as claimed in claim 13, wherein said positioning operation portion comprises a spherical shape which rotates about a center of a sphere of 10-30 cm in diameter.