Abstract:
A configuration is presented that enables viewing a plurality of data objects situated in a virtual space as the visual field defined in the virtual space is changed smoothly; and that at the same time enables: supplemental information in connection with displayed data objects to be displayed; information in connection with displayed data objects to be displayed in more detail; means for dialogue with a user to be provided in situations where required; and application programs linked to the display of information and associated with that information to be executed. Included are: a step of accepting virtual-viewpoint position changes; a step of continuously changing visual field based on the virtual-viewpoint position changes, and uninterruptedly changing the display of a data object positioned within the visual field; a step of determining whether a data object positioned within the visual field satisfies predetermined geometric conditions for the visual field; and in respect of a data object that satisfies the predetermined geometric conditions, a step of executing a process preset in that data object.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
   The present application claims priority under 35 USC §119 from Japanese Patent Publication No. 2001-363240, filed Nov. 28, 2001, the disclosure of which is incorporated herein by reference. The present application is a continuation of U.S. application No. Ser. No. 10/083,540 filed Feb. 27, 2002 now U.S. Pat. No. 6,828,964, which has been allowed, the disclosure of which is incorporated herein by reference. 

   BACKGROUND OF THE INVENTION 
   1. Technical Field 
   The present invention relates to a display method and display control device for displaying, in accordance with a visual field from a set viewpoint, data objects situated in a three-dimensional virtual space. 
   2. Description of Related Art 
   Computers connected to networks, such as the Internet for example, are capable of retrieving massive amounts of diverse information. In addition, as the capacity of storage media increases, even stand-alone information machines have become able to utilize vast amounts of diverse information. 
   In order to make use of such large amounts of diverse information, GUIs (graphical user interfaces) that employ a desktop metaphor, such as Microsoft Windows™ are being used, as are web browsers such as Microsoft Internet Explorer™ and Netscape Navigator™. These applications display viewing target informational content arranged on a screen in a static and planar manner; and in order to view the informational-content items in turn, succeeding subject matter must be displayed by replacing the subject matter being displayed in the active window, or must be displayed by changing the active attribute of windows being displayed on the screen in an overlapping manner. 
   When a plurality of informational items is displayed by switching from one display to another, the sense of continuity on the screen is lost, leading to the problem of a 25 user having trouble understanding how the individual contents are related to each other. 
   In order to solve such problems, an information display method has been proposed (Japanese Pat. App. No. 2001-162322 [filed May 30, 2001]; Laid-Open No. 2000-172248) wherein concatenatedly linked data objects are arranged in a three-dimensional virtual space, and based on a visual field defined in the virtual space, the data objects are displayed on a display screen; and wherein information can be perused by following along links while the display screen is changed uninterruptedly by changing the visual field smoothly. 
   A conventional technique of this sort will be explained using  FIGS. 5 and 6 .  FIG. 5  is a conceptual view of a link structure of concatenatedly linked data objects, and  FIG. 6   10  is example displays of the concatenatedly linked data objects. 
   In  FIG. 5 , data objects  102  and  103  are represented within data object  101  as links  112  and  113 , respectively, and data objects  104  and  105  are represented within data object  102  as links  114  and  115 , respectively. Data object  106  is represented within data object  104  as link  116 . 
   In display example  301  at (A) in  FIG. 6 , data object  101  and data objects  102  and  103  linked to data object  101  are displayed. 
   When a shift-viewpoint instruction is accepted, the display range is changed according to the instruction, transitioning, for example, to the state shown in display example  302  at (B) in  FIG. 6 . In this display example  302 , data object  101 , data object  102  linked to data object  101 , and data objects  104  and  105  linked to data object  102  are displayed. 
   When a further shift-viewpoint instruction is accepted, the state shown in display example  303  at (C) in  FIG. 6  ensues. In this display example  303 , data object  102 , data object  104  linked to data object  102 , and data object  106  linked to data object  104  are displayed. 
   In display examples  301  through  304 , the data object that occupies the largest area within the display screen is displayed in detail, and the preceding/following relationships of the data objects are set in correspondence with the link modes and displayed. The fact that the display within the field of view always changes smoothly in response to the shift-viewpoint instructions enables a user to follow the links and view the data objects. 
   The information display method described above readily enables viewing by following concatenatedly linked information, and enables remedying the problem of losing sight of the interrelationships among the informational-content items. However, this method does not take into consideration such matters as: displaying supplemental information in connection with displayed data objects; displaying information in more detail in connection with displayed data objects; providing means for dialogue with a user in situations where required; or executing application programs linked to the display of information and associated with that information. 
   SUMMARY OF THE INVENTION 
   The present invention offers a configuration that enables viewing a plurality of data objects situated in a virtual space as the visual field defined in the virtual space is changed smoothly; and that at the same time enables: supplemental information in connection with displayed data objects to be displayed; information in connection with displayed data objects to be displayed in more detail; means for dialogue with a user to be provided in situations where required; and application programs linked to the display of information and associated with that information to be executed. 
   A first aspect of the present invention is a data-object display method for situating a plurality of data objects within a three-dimensional virtual space in which a visual field is defined and displaying, from a set virtual viewpoint, data objects located within the visual field. The data-object display method includes: a step of accepting virtual-viewpoint location changes; a step of continuously changing the visual field based on the virtual-viewpoint location changes, and uninterruptedly changing the display of a data object located within the visual field; a step of distinguishing whether a data object located within the visual field satisfies predetermined geometric conditions for the visual field; and a step of executing, in respect of a data object satisfying the predetermined geometric conditions, a process preset in the data object. 
   In a second aspect, the invention is the data-object display method according to the first aspect, wherein the process preset in the data object displays a display image different from a virtual-space display image located within the visual field. 
   A third aspect is the data-object display method according to the second aspect, wherein the a separate image is displayed situated in front of the data object located within the visual field in the virtual space. 
   In a fourth aspect, the invention is the data-object display method according to the second aspect, wherein a separate image is displayed within a window different from a window in which the data object located within the visual field in the virtual space is displayed. 
   A fifth aspect of the invention is the data-object display method according to the second aspect, wherein a separate image is displayed within a frame different from, in an identical window with, a frame in which the data object located within the visual field in the virtual space is displayed. 
   In a sixth aspect, the invention is according to the second aspect, wherein at least one from among a message, a modal dialogue, a modeless dialogue or information related to the data object is displayed. 
   A seventh aspect of the invention is the data-object display method according to  5  any of the foregoing aspects, wherein the process preset in the data object executes a preset application program. 
   An eighth aspect of the present invention is an information display device for situating a plurality of data objects within a three-dimensional virtual space in which a visual field is defined and displaying, from a set virtual viewpoint, data objects located within the visual field. The information display device in this aspect of the invention includes: visual-field-data updating means for accepting virtual-viewpoint location changes; object data processing means for continuously changing the visual field based on the virtual-viewpoint location changes, and uninterruptedly changing the display of a data object located within the visual field; process-execute-conditions judging means for distinguishing whether a data object located within the visual field satisfies predetermined geometric conditions for the visual field; and visual-field-shift-linked process-executing means for executing, in respect of a data object satisfying the predetermined geometric conditions, a process preset in the data object. 
   An ninth aspect of the present invention is an information display device for situating a plurality of data objects within a three-dimensional virtual space in which a visual field is defined and displaying on a display screen, from a set virtual viewpoint, data objects located within the visual field. The information display device herein includes: visual-field-data updating means for accepting virtual-viewpoint location changes; object data processing means for continuously changing the visual field based on the virtual-viewpoint location changes, and uninterruptedly changing the display of a data object located within the visual field; process-execute-conditions judging means for distinguishing whether or not there is a data object located in the display-screen center and occupying a proportion of the display screen that is a predetermined value or more; and visual-field-shift-linked process-executing means for executing a process preset in the data object, based on judgment results from said process-execute-conditions judging. 
   An tenth aspect of the present invention is an information display device for situating a plurality of data objects within a three-dimensional virtual space in which a visual field is defined and displaying, from a set virtual viewpoint, data objects located within the visual field. The information display device in the aspect of the present invention includes: visual-field-data updating means for accepting virtual-viewpoint location changes; object data processing means for continuously changing the visual field based on the virtual-viewpoint location changes, and uninterruptedly changing the display of a data object located within the visual field; and visual-field-shift-linked process-executing means for executing, if the distance of a data object located in the visual field from the virtual viewpoint becomes a predetermined value, a process preset in the data object. 
   From the following detailed description in conjunction with the accompanying drawings, the foregoing and other objects, features, aspects and advantages of the present invention will become readily apparent to those skilled in the art. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a functional block diagram illustrating the configuration of one embodiment of the present invention; 
       FIG. 2  is a functional block diagram illustrating a portion of  FIG. 1  in greater detail; 
       FIG. 3  is a control flowchart; 
       FIG. 4  is an explanatory diagram illustrating the geometric relationship between a visual field and a data object in a three-dimensional virtual space; 
       FIG. 5  is an explanatory diagram illustrating one example of the link structure of a group of data objects; 
       FIG. 6  is explanatory diagrams illustrating the link structure of a group of data objects, according to conventional technology; 
       FIG. 7  is an explanatory diagram illustrating a link structure, as set out in the present invention, for data objects to be displayed; 
       FIG. 8  is explanatory diagrams illustrating examples of message display linked to visual-field shift; 
       FIG. 9  is explanatory diagrams illustrating examples of modal-dialogue display linked to visual-field shift; 
       FIG. 10  is explanatory diagrams illustrating examples of related-information display linked to visual-field shift; 
       FIG. 11  is explanatory diagrams illustrating examples of display, linked to visual-field shift, of related information into a separate window; 
       FIG. 12  is explanatory diagrams illustrating examples of display, linked to visual-field shift, of related information into a separate frame; 
       FIG. 13  is explanatory diagrams illustrating examples of modeless-dialogue display linked to visual-field shift; and 
       FIG. 14  is explanatory diagrams illustrating examples of application-execution display linked to visual-field shift. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     FIG. 1  is a control block diagram of an information-processing device employing a first embodiment of the present invention. 
   An information processing device  500 , which can be a personal computer, workstation or other type of computer, includes an input device  501 , which may be a keyboard, mouse or the like; an information storage device  502 , which may be a hard disk, CD-ROM or other information recording device; a network interface  503 , which is capable of connecting to the Internet, a LAN or the like; a program-storage unit  504 , which may be a ROM, hard disk or the like; a cache data storage unit  505 , comprising RAM or other memory; a display device  507 , which may be a cathode ray tube, liquid crystal display or the like; a frame memory  506 , which stores image data for images displayed on the display device  507 ; and a data processing unit  510 , which generates image data to be displayed on the display device  507 . 
   The data processing unit  510  comprises a CPU and memory, and includes: a process-control module  512 , a visual-field-data updating module  511 , an object-data processing module  514 , visual-field-shift-linked process-executing module  517 , and a display-image synthesizing module  519 , among other modules. The configuration may be made to have object-data processing modules  514  and visual-field-shift-linked process-executing modules  517  of a number of different kinds, to correspond to types of data objects or types of visual-field-shiftlinked processes; generally, these are realized in a form in which programs stored in the program-storage unit  504  are loaded onto memory and deployed. 
   Of the elements of the data processing unit  510 , the process-control module  512  controls overall processing. 
   The visual-field-data updating module  511  accepts instructions relating to visual field movement inputted from the input device  501 , moves a virtual viewpoint, and continuously shifts visual field data  513  within a virtual space seen from the virtual viewpoint. The display-image synthesizing module  519  synthesizes the partial display images generated by the object-data processing module  514  and visual-field-shift-linked process-executing module  517 , respectively, and generates an appropriate display image to be “displayed on the display device  507 . 
   Object data is stored in a data storage unit  530 . Object data is information acquired via the network interface  503  or information stored in the information storage device  502 , and is present as a plurality of items corresponding to data objects that are candidates for being placed in the virtual space and displayed. 
   As shown in  FIG. 2 , object data  531  stored in the data storage unit  530  includes: object placement data  532 , which defines information relating to placement of a data object in a virtual space; object display content data  533 , which defines display content for a data object; and visual-field-shift-linked process content-defining data  534 , which defines the content of a process that is executed in conjunction with shifting the visual field, and, for executing that process, conditions that pertain to the geometric relation between the visual field and the target object. 
   The object-data processing module  514  carries out processes relating to a specified type of data object, and includes an object display image generation function unit  515  and a visual-field-shift-linked processing module  516 . 
   In the object-data processing module  514 , the object display image generation function unit  515  generates a data object display image based on the current visual field data  513  for a virtual space in which a plurality of data objects are placed. The object display image generation function unit  515 , each time a new display image frame is generated, generates a display image for a data object that is to be displayed, based on the visual field data  513 , object placement data  532 , and object display content data  533 , and writes this display image to the frame memory  506  via the display-image synthesizing module  519 . 
   The visual-field-shift-linked processing module  516  refers to the visual field data  513 , object placement data  532 , and visual-field-shift-linked process content-defining data  534  to control execution of pre-set processes in conjunction with shifting the visual field. This visual-fieldshift-linked processing module  516  includes a process-execute-conditions judging module  521 , which based on the visual field data  513 , object placement data  532 , and visual-field-shiftlinked process content-defining data  534 , judges from the geometric relation between visual field and data object whether conditions have been met for executing preset processes in conjunction with visual field movement. The visual-field-shift-linked processing module  516  controls the processes of the visual-field-shift-linked process-executing module  517  based on the determination results of the process-execute-conditions judging module  521 . 
   The visual-field-shift-linked process-executing module  517 , in conformance with control functions of the visual-field-shift-linked processing module  516 , executes processes designated in the visual-field-shift-linked process content-defining data  534 . The visual-field-shift-linked process-executing module  517  includes a visual-field-shift-linked information displaying module  518 ; and of the processes designated in the visual-field-shift-linked process content-defining data  534 , this visual-field-shift-linked information displaying module  518  generates display content for the display device  507 , which it writes to the frame memory  506  via the display-image synthesizing module  519 . 
   The configuration as described above enables the display of data objects while smoothly changing the display range by continuously shifting the visual field, in a virtual space in which a plurality of data objects are situated, and enables the execution of information display and like processes when predetermined geometric conditions between the visual field, the data objects in which they are pre-established, are met. 
   Process Flowchart 
   The flowchart shown in  FIG. 3  will be used to explain the operations of the above-described information processing device  500 . 
   When processing commences in Step  5401 , visual field data is updated in Step  5402 . Specifically, the visual field data  513  is updated by the visual-field-data updating module  511  based on instructions relating to visual field movement inputted from the input device  501 . 
   In Step S 403  a frame memory region ( 506 ) for depicting a data object based on the visual field in a virtual space is initialized. 
   In Step S 404 , based on visual field data and object data, the data object to be displayed is decided. Specifically, based on the current visual field data  513  and object data  531 , and giving consideration to distance from viewpoint and link relation with other data objects, a data object that is present within the visual field is selected as the data object to be displayed. A plurality of data objects to be displayed can be selected. 
   In Step S 405 , determination is made of whether there are any data objects to be displayed that have not been displayed. If it is determined that there are data objects that have not yet been displayed, control proceeds to Step S 406 ; if it is determined that there are no data objects that have not been displayed, control proceeds to Step  5409 . 
   In Step S 406 , one data object is selected from among the data objects that have not yet been displayed; based on visual field data  513  and object data  531 , a display image of that data object is generated and depicted on the corresponding region of the frame memory  506  via the display-image synthesizing module  519 . 
   In Step S 407 , it is determined whether the data object selected in Step S 406  fulfills the conditions for execution of a visual-field-shift-linked process defined in the visual-field-shift-linked process content-defining data  534 . For example, if the data “object is present on an axial line that passes through the center of the display screen, and it appears in a size that is at least one-third of the display screen, it is determined that the conditions for executing the visual-field-shift-linked process are met, and control proceeds to Step S 408 ; if the conditions are not met, control returns to Step S 405 . 
   In Step S 408 , based on the visual field data  513 , object placement data  532  and visual-field-shift-linked process content-defining data  534 , the visual-field-shift-linked to process is executed. If in the visual-field-shift-linked process content data, there are instructions for information display on the display screen, display content is prepared by the visual-field-shift-linked information displaying module  518  and depicted on the corresponding region in the frame memory  506  via the display-image synthesizing module  519 . Thereafter, control proceeds to Step S 405 . 
   In Step S 409 , the contents of the frame memory  506  are outputted to the display device  507 . 
   In Step S 410 , it is determined whether or not to conduct a process for the next display-image frame. If the process for the next display-image frame is to be conducted, control proceeds to Step S 402 ; if not, control proceeds to Step S 411  and the processends. 
   The geometric relation between a visual field and data object in a three-dimensional virtual space can be represented, for example, as in  FIG. 4 . 
   A data object  605  placed within a three-dimensional virtual space will have its display conditions changed based on its relationship with a current viewpoint  601 . As shown in the figure, the region within a pyramid having the viewpoint  601  as apex is the visual field displayed on the display screen. When the visual field changes because of shift of the viewpoint  601  and changes in the angle of elevation, the position of data object  605  relative to the visual field changes, avid the display screen changes smoothly. 
   The determination of whether condition have been met for execution of the visual-field-shift-linked process, said determination to be made in the process-execute conditions judging module  521 , can be determination of whether the relationship between visual field coordinate system  603  having viewpoint  601  as its origin and local coordinate system  604  having as its origin the central point of data object  605  meets specific conditions. 
   Data Object Link Structure 
   One example of the link structure of data objects to be displayed will be explained using the schematic diagram of  FIG. 7 . 
   Visual-field-shift-linked processes  221  through  226  are attendant on data objects  201  through  206  concatenatedly linked by links  212  through  216 . 
   In the example shown, links  212  and  213  for data objects  202  and  203  are provided in data object  201 , attendant on which is a visual-field-shift-linked process  221  for displaying a message. Links  214  and  215  for objects  204  and  205  are provided in data object  202 , attendant on which is a visual-field-shift-linked process  222  for displaying a modal dialogue. 
   A visual-field-shift-linked process  223  for activating application X is attendant on data object  203 . A link  216  for data object  207  is provided in data object  204 , attendant on which is a visual-field-shift-linked process  224  for displaying document A in a different window. 
   A visual-field-shift-linked process  225  for displaying a modeless dialogue is attendant on data object  205 . A visual-field-shift-linked process  226  for displaying  25  document B in a different window is attendant on data object  206 . 
   When data objects  201  through  206 , which are to be displayed, meet predefined conditions for execution of visual-field-shift-linked processes  221  through  226 , these visual-field-shift-linked processes  221  through  226  are executed. 
     FIGS. 8 through 14  show examples of display screens for cases where viewpoint is shifted with regard to a group of data objects to be displayed, causing the visual field to shift. 
     FIG. 8  shows a case where display of a message is linked to movement of the visual field. 
   In display example  311  at (A) in  FIG. 8 , data objects  201 ,  202  and  203  are displayed. In this state, none of the data objects  201  through  203  have met the conditions for executing their respective visual-field-shift-linked processes. 
   Display example  312  at (B) in  FIG. 8  shows a state where the viewpoint has been moved forward, causing the entire visual field to advance, and the data objects  201  through  203  are displayed larger than in display example  311 . At such time, the conditions for executing visual-field-shift-linked process  221  attendant on data object  201  have been met, and so a message  231  is displayed. 
   Display example  313  at (C) in  FIG. 8  shows a state where the viewpoint has been moved further forward from display example  312 ; the data objects  201  through  203  are displayed even larger than in the display example  312 . At this time, the conditions for executing visual-field-shift-linked process  221  attendant on data object  201  are no longer met, and so the message ceases to be displayed. 
     FIG. 9  shows a case where display of a modal dialogue is linked to movement of visual field. As used herein, a modal dialogue is a dialogue that, while it is being displayed, accepts no operations other than operations relating to the dialogue. 
   Display example  321  at (A) in  FIG. 9  shows a state that is the same as in (C) in  FIG. 8 ; data object  202  is displayed in the center foreground. Data objects  204  and  205  are linked to this data object  202 ; however, these are not yet displayed in this display example  321 . 
   The display example  322  at (B) in  FIG. 9  shows a state where the viewpoint has been moved slightly forward from the state in the display example  321 ; the conditions are met for execution of visual-field-shift-linked process  222  attendant on data object  202 , and a modal dialogue  232  is displayed. The modal dialogue in this example displays a box for inputting a password, an OK function button and a cancel function button. In this state, visual-field-shift-linked process-executing module  517  is constituted to block any instructions relating to movement of visual field, and no operations are accepted other than inputting a determined password in the password input box and clicking on the OK function button; or clicking on the cancel function button. 
   When the proper password is inputted in the modal dialogue  232  of the display example  322  and the OK function button is clicked, visual-field-shift-linked process-executing module  517  ceases to block visual field movement instructions, and movement of visual field becomes possible again, and data objects  204  and  205  linked from data object  202  can now be displayed. This brings about the state shown in display example  323  at (C) in  FIG. 9 . 
     FIG. 10  shows a case where the display of information relating to a data object is linked with movement of visual field. As used herein, information relating to a data object is, for example, a web page relating to a data object to be displayed. In this example, information relating to a data object is displayed in a document display window  233  opened in front of a data object display image in the visual field of a virtual space on a display screen. 
   In display example  331  at (A) in  FIG. 10 , the visual field has been advanced even further than in display example  323  at (C) in  FIG. 9 , and the data objects  202  and  204  are displayed. 
   The display example  332  at (B) in  FIG. 10  shows a state where the visual field has been moved slightly forward in comparison to display example  331 ; data object  204  is displayed large, and data object  206  linked with data object  204  is also displayed. In addition the conditions have been met for execution of visual-field-shift-linked process  224  attendant on data object  204 ; a document display window  233  is displayed in the foreground, and document A is displayed in this window. 
   The display example  333  at (C) in  FIG. 10  shows a state where the visual field has been moved slightly forward in comparison to display example  332 ; the data objects  204  and  206  are displayed slightly larger. At this time, because the conditions for execution of visual-field-shift-linked process  224  have remained met, document A of the document display window  233  continues to be displayed. The document display window  233 , the display position and size of which are not linked to visual field and thus do not change, is displayed in a fixed position on the display screen. The document display window  233  may be constituted so that the position thereof changes according to the display position of an important data object to be displayed, so as to avoid the area where such data object is being displayed. 
   The display example  334  at (D) in  FIG. 10  shows a state where the visual field has been moved slightly forward in comparison to display example  333 ; data object  206  is displayed large. At this time, the conditions are met for execution of visual-field-shift-linked process  226  attendant on data object  206 , and in place of document A document B is displayed in the document window  233 . 
     FIG. 11  shows a case where a display image of a data object based on the visual field within a virtual space is displayed in a data object display window  234 ; in this figure, data object-related information linked to the movement of visual field is displayed, as in  FIG. 10 . 
   In the display example  341  at (A) in  FIG. 11 , data object  202  to be displayed is displayed in the data object display window  234 . When the visual field of the data object display window  234  in display example  341  is moved forward so that the conditions are met for execution of visual-field-shift-linked process  224  attendant on data object  204 , the document display window  233  pops up and the document A is displayed, as shown in display example  342  at (B) in  FIG. 11 . Similarly, when the conditions are met for execution of visual-field-shift-linked process  226  attendant on data object  206 , document B is displayed within the document display window  233 , as shown in display example  343  at (C) in  FIG. 11 . 
     FIG. 12  shows an example of display image and related information of a data object based on the visual field in a virtual space being displayed in a separate frame within a browser window  235  on the display screen. In this case, too, as with  FIG. 10  and  FIG. 11 , a case is shown where data object-related information linked to visual field movement is displayed. 
   In display example  351  at (A) in  FIG. 12 , a web browser such as Microsoft Internet Explorer™ is used, and document S is displayed within the browser window  235 . 
   The display example  352  at (B) in  FIG. 12  shows a state where in the document S displayed in display example  351 , a link that calls up the next display has been clicked. Specifically, data object display frame  236  and document display frame  237  are displayed within the browser window  235 ; and data object  202  and others are displayed based on a visual field defined within a virtual space, and document T is displayed within the document display frame  237 . 
   The display example  353  at (C) in  FIG. 12  shows a state where the visual field is moved slightly forward from the state in the data object display frame  236  of the display example  352 ; data object  204  is displayed large, and the conditions are met for execution of visual-field-shift-linked process  224  attendant on data object  204 , and document T in the document display frame  237  is replaced by document A. 
   The display example  354  at (D) in  FIG. 12  shows a state where the visual field is moved slightly forward from the state in the data object display frame  236  of the display example  353 ; data object  206  is displayed large, and the conditions are met for execution of visual-field-shift-linked process  226  attendant on data object  206 , causing document A in the document display frame  237  to be replaced by document B. 
     FIG. 13  shows an example of display of modeless dialogue being linked to visual field movement. As used here, modeless dialogue is a dialogue such that operations not related to the dialogue are permitted even when the dialogue is displayed. 
   In the display example  361  at (A) in  FIG. 13 , the data objects  202 ,  204  and  205  are displayed. 
   The display example  362  at (B) in  FIG. 13  shows a state where the visual field is moved slightly forward from the state in display example  361 ; data object  205  is displayed large, and the sample video image included in data object  205  is a still image. In this case the conditions are met for execution of visual-field-shift-linked process  225  attendant on data object  205 , and so a modeless dialogue  238  is displayed. The modeless dialogue  238  in this example has a play button for giving instructions to play the video, making possible the playing of the video, a sample of which is displayed as a still image. The state where this modeless dialogue  238  is displayed differs from the state where a modal dialogue is displayed, as it is possible to move the visual field in this state. 
   The display example  363  at (C) in  FIG. 13  shows the image displayed when the play button of the modeless dialogue  238  in the display example  362  has been clicked, and a video image is played on data object  205 . In addition, as shown in the figure, while the video image is being played, there is display of a modeless dialogue having a stop button for stopping the video image. 
   The display example  364  at (D) in  FIG. 13  shows a state where the visual field has been moved slightly forward from display example  363 ; data object  205  is displayed  10  slightly larger, and the play of the video image continues. 
     FIG. 14  shows an example of the execution of an application linked to visual field movement. 
   In the display example  371  at (A) in  FIG. 14 , the data objects  201 ,  202  and  203  are displayed. 
   The display example  372  at (B) in  FIG. 14  shows a state where the visual field has been moved slightly forward from the display example  371 ; data object  203  is displayed large, and the conditions are met for execution of the  223  attached to data object  203 , causing the display of the modeless dialogue  239  for confirming whether to activate the application. This modeless dialogue  239  has an OK function button for activating the application and a cancel button; when the OK function button is clicked, the application is activated. 
   As shown at (C) in  FIG. 14 , when the OK function button is clicked, the modeless dialogue  239  is no longer displayed; in its place the application window  240  appears, and it is now possible to use the application. 
   OTHER EMBODIMENTS  
   In the above-described embodiments, determination of whether conditions for execution of the visual-field-shift-linked processes have been met is based on the geometric relationship between the visual field and the various data objects; other conditions, however, may be used. For example, priority values may be computed for all data objects to be displayed, the data object with the highest priority value is deemed the representative object, and determination of whether execution conditions have been met for the visual-field-shift-linked processes is made only for the representative object. Alternatively, conditions may be set that are unrelated to visual field movement. 
   For example, when a data object is positioned in the middle of the screen, and the size at which it appears is at least a predetermined proportion of the screen width (for example, at least one third), the visual-field-shift-linked process is executed. In such a case, if there are a plurality of data objects that meet execution conditions, priority in execution can be given starting those data objects that have a low order in the link relationship. 
   The present invention allows the viewing of multiple data objects placed in a virtual space as a visual field defined in that virtual space is fluidly shifted; the present invention also allows the display of additional information relating to a data object to be displayed, provides means for when dialogue with a user is required, and allows for the execution of application programs linked to data objects and related thereto. 
   Only selected embodiments have been chosen to illustrate the present invention. To those skilled in the art, however, it will be apparent from the foregoing disclosure that various changes and modifications can be made herein without departing from the scope of the invention as defined, in the appended claims. Furthermore, the foregoing description of the embodiments according to the present invention is provided for illustration only, and not for limiting the invention as defined by the appended claims and their equivalents.