Patent Publication Number: US-2022212097-A1

Title: Virtual image display program, virtual image display apparatus, and virtual image display method

Description:
CLAIM OF PRIORITY 
     This application claims priority from U.S. patent application Ser. No. 16/524,311, filed on Jul. 29, 2019, entitled “VIRTUAL IMAGE DISPLAY PROGRAM, VIRTUAL IMAGE DISPLAY APPARATUS, AND VIRTUAL IMAGE DISPLAY METHOD,” which in turn claims priority to U.S. patent application Ser. No. 15/196,410, now U.S. Pat. No. 10,406,432, filed on Jun. 29, 2016, which in turn claims priority to Japanese Patent Application Publication No. 2015-183379, filed on Sep. 16, 2015, the entire contents of which are hereby incorporated by reference. 
    
    
     FIELD 
     The present invention relates to a virtual image display program, a virtual image display apparatus, and a virtual image display method for displaying an image of virtual space on a display. 
     BACKGROUND 
     Virtual reality games played by displaying an image of virtual space on a head-mounted display (hereinafter referred to as “HMD”) worn on the head of a player are understood in the art (see Japanese Unexamined Patent Application Publication No. 7-200162, for example). An example HMD may include, in an example configuration, a gyro sensor, with which the movement of the head of the player is detectable. When the player moves his/her head, the HMD changes the image displayed on the display in order to follow the movement of the head of the player. When the game image follows the movement of the head of the player as mentioned here, the player may stay more immersed in the game, and may accordingly be able to concentrate more on the game. 
     Virtual reality games, like other games, may sometimes provide information to a user; for example, they may display hints on the progress of the game, or may display menu items. However, this is most often accomplished by displaying a button, such as a menu button, together with an image of virtual space, such that when the button is selected, information may be provided. However, this results in a significantly reduced sense of immersion in the virtual space. Such a problem is not limited to virtual reality games, and may be present in a variety of displays of images of virtual space. 
     SUMMARY 
     According to an exemplary embodiment, a virtual image display program, a virtual image display apparatus, and a virtual image display method capable of providing information while reducing the loss of a sense of immersion in virtual space may all be provided. 
     According to an embodiment of the present invention, there may be provided a virtual image display program for displaying an image of virtual space on a display that displays an image by using a virtual image display apparatus, a detector for identifying a position and direction of a certain body part of a player, and the display. The virtual image display apparatus may include a controller and a storage unit where an information providing condition and to-be-provided information may be recorded. The program may cause the controller to function as a space image output unit and an information provider. The space image output unit may display the image of the virtual space on the display in accordance with the position and direction of the certain body part of the player. The information provider may output the to-be-provided information when the information providing condition regarding the position and direction of the certain body part of the player is satisfied. Accordingly, the information provider may execute information provision on the condition that the information providing condition regarding the movement of the gaze position of the player is satisfied. According to such an embodiment, there may be no need to display a button for executing information provision on an image of the virtual space. In doing so, information can be provided while reducing the loss of a sense of immersion in the virtual space. 
     According to various exemplary embodiments, the virtual space may include a target object selectable by a gaze of the player, an area including the target object may be recorded in the storage unit, the information providing condition may include the fact that a gaze position identified from the position and direction of the certain body part of the player becomes outside the area, and the controller may output the to-be-provided information when the gaze position of the player becomes outside the area. Accordingly, information can be provided when selection of a target object is interrupted, such as when the player is not sure about how to progress the game. In doing so, information provision can be executed with the appropriate timing. 
     According to various exemplary embodiments, the virtual space may include a target object selectable by a gaze of the player, the information providing condition may include the fact that a gaze position identified from the position and direction of the certain body part of the player moves outside the target object before the player completes selecting the target object, and the controller may output the to-be-provided information when the gaze position of the player moves outside the target object before the player completes selecting the target object. Accordingly, information can be provided when the player fails in selecting a target object. In doing so, information provision can be executed with the appropriate timing. 
     According to various exemplary embodiments, a reference range regarding movement of the certain body part of the player may be recorded as the information providing condition in the storage unit, the information providing condition may include the fact that the movement of the certain body part of the player becomes outside the reference range, and the controller may output the to-be-provided information when the movement of the certain body part of the player becomes outside the reference range. Accordingly, the information providing condition may be satisfied when the movement range of the certain body part is too narrow or too wide. In doing so, information provision can be executed with the appropriate timing. 
     According to various exemplary embodiments, a predetermined movement of the certain body part of the player may be recorded in the storage unit, the information providing condition may include the fact that movement of the certain body part of the player corresponds to the predetermined movement recorded in the storage unit, and the controller may output the to-be-provided information when the movement of the certain body part of the player corresponds to the predetermined movement. Accordingly, the information providing condition may be satisfied when the movement range of the certain body part corresponds to the predetermined movement. In doing so, information provision can be executed with the appropriate timing. 
     According to an exemplary embodiment, the information provider may display the to-be-provided information on an object in the virtual space. Accordingly, information can be provided to the player in a natural form. 
     According to an exemplary embodiment, the information provider may display the to-be-provided information in a direction in which a moving body moves, the moving body being an object in the virtual space and moving in the virtual space. In doing so, information can be provided without reducing a sense of immersion in the virtual space. 
     Therefore, according to the virtual image display program, the virtual image display apparatus, and the virtual image display method according to the embodiments of the present invention, information can be provided while reducing the loss of a sense of immersion in a virtual space. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Exemplary  FIG. 1  is a schematic diagram describing an exemplary embodiment of a virtual image display system. 
       Exemplary  FIG. 2  is a conceptual diagram illustrating an exemplary embodiment of a gameable area in virtual space. 
       Exemplary  FIG. 3  is a flowchart illustrating an exemplary embodiment of the procedure of a game progressing process. 
       Exemplary  FIG. 4  is a flowchart illustrating an exemplary embodiment of the procedure of an information providing process. 
       Exemplary  FIG. 5  is a schematic diagram illustrating an exemplary embodiment of an image that may be displayed on a virtual image display. 
       Exemplary  FIG. 6  is a schematic diagram illustrating an exemplary embodiment of an image that may be displayed on a virtual image display, wherein a hint is displayed. 
       Exemplary  FIG. 7A  is a diagram illustrating an exemplary embodiment of an image that may be displayed on a virtual image display, in a state where attention is being paid to a target object. 
       Exemplary  FIG. 7B  is a diagram illustrating an exemplary embodiment of an image that may be displayed on a virtual image display, in a state where a hint is displayed. 
     
    
    
     DETAILED DESCRIPTION 
     Hereinafter, a virtual image display program, a virtual image display apparatus, and a virtual image display method according to a first exemplary embodiment will be described. According to an exemplary embodiment, the virtual image display apparatus may be implemented as a game processing apparatus that progresses a game while displaying an image of virtual space. The gameplay of this game may progress according to the assumption that the player will wear a head-mounted display (HMD) on his/her head. 
     Referring to  FIG. 1 , the configuration of a system including an HMD  10  and a game processing apparatus  20  will be described. At first, the configuration of the HMD  10  connected to the game processing apparatus  20  will be described. The HMD  10  may include an HMD controller  11 , a sensor  12  serving as a detector, and an input/output interface unit (I/F unit)  13 . The HMD controller  11  may output various types of information to the game processing apparatus  20  and may receive various types of information from the game processing apparatus  20  via the input/output I/F unit  13 . The sensor  12  may be or may include a detector for identifying the position and direction of the head of the player. According to an exemplary embodiment, the sensor  12  may include at least one of a gyro sensor, an acceleration sensor, and a geomagnetic sensor, and may detect the movement of the head of the player. Alternatively, a device that directly detects the movement of the eyeballs of the player, such as a line-of-sight detecting sensor that emits near-infrared light into the iris and detects its reflected light, may be used as the sensor  12 . According to an exemplary embodiment, the head of the player may be the certain body part of a player that has its position and direction identified and tracked. 
     The HMD  10  may include a display  14  that displays an image, and a loudspeaker  15  that outputs sound. For example, according to an exemplary embodiment, the display  14  may display an image to be visually recognized by the left eye and an image to be visually recognized by the right eye with a parallax. This may allow the player to visually recognize a stereoscopic image while perceiving a sense of depth. The HMD controller  11  may display on the display  14  an image in accordance with an image signal received from the game processing apparatus  20  via the input/output I/F unit  13 . According to an exemplary embodiment, the loudspeaker  15  may be, for example, a headphone, and may be used to, for example, output sound effects and sound that describe the progress of the game. 
     Next, the configuration of the game processing apparatus  20  will be described. The game processing apparatus  20  may include a controller  21 , a storage unit  22 , and an input/output unit  23 . The controller  21  may include hardware elements including a central processing unit (CPU), random-access memory (RAM), and read-only memory (ROM). The controller  21  may include a gaze position identifying unit  24 , a game manager  25 , a space image output unit  26 , and an information provider  27 . According to an exemplary embodiment, the controller  21  may cause the hardware elements to execute the virtual image display program to function as the gaze position identifying unit  24 , game manager  25 , space image output unit  26 , and information provider  27 . 
     According to an exemplary embodiment, the storage unit  22  may store virtual space image information  30 , object information  31 , provision condition information  32 , gaze position information  33 , gaze time information  34 , and to-be-provided information  35 . 
     According to an exemplary embodiment, the virtual space image information  30  may be data for rendering an image of the virtual space background and objects. The objects may include target objects, which are selectable, and non-selectable objects. In an exemplary embodiment, the player may be able to select a target object by continuously gazing at the target object for a certain period of time. 
     According to an exemplary embodiment, the object information  31  may be information that indicates each object&#39;s attributes. Specifically, the object information  31  may include each object&#39;s identifier, coordinates in the virtual space, type, and selection state. The object&#39;s type may be, for example, information that indicates whether the object is a target object or an object other than a target object. The object&#39;s selection state may be information that indicates, when the object is a target object, whether the object is selected or not. 
     According to an exemplary embodiment, the provision condition information  32  may be information that defines an information providing condition, which may be defined as a condition for providing information to the player. According to an exemplary embodiment, the provision condition information  32  may be information that defines, when the time elapsed since the start of the game is a certain time or longer, the gaze position of the player is outside a gameable area set in the virtual space. The gameable area may be an area where the player can select a target object by gazing at that object, and may include all target objects. For example, the provision condition information  32  may include coordinate information of the gameable area. When the information providing condition is satisfied, the player may be given a hint on the progress of the game. 
     According to an exemplary embodiment, the gaze position information  33  may be information that indicates the identified gaze position of the player, in terms of coordinates, in the virtual space. The gaze time information  34  may be information that indicates a period of time in which the player continuously gazes at a target object. The to-be-provided information  35  may include information that indicates the details of a hint for accomplishing a mission of the game. 
     According to an exemplary embodiment, the gaze position identifying unit  24  may receive a detection signal obtained by the sensor  12 , from the HMD controller  11  of the HMD  10 , worn on the player, via the input/output unit  23 . The gaze position identifying unit  24  may identify the gaze position, in terms of coordinates, in the virtual space in accordance with the received detection signal, and may update the gaze position information  33  with the identified gaze position. 
     The game manager  25  may compare the gaze position information  33  with the object information  31  and may determine whether the gaze position is on a target object. When the game manager  25  determines that the gaze position is on a target object, the game manager  25  may measure a time (gaze time) in which the player continuously gazes at the target object, and may update the gaze time information  34  with the gaze time. The game manager  25  may also determine whether the gaze time, indicated by the gaze time information  34 , has reached a certain predetermined time (such as, for example, three seconds). When the gaze time information  34  has reached the certain predetermined time, the game manager  25  may determine that selection of the target object is completed. 
     The game manager  25  also determines whether a mission of the game has been completed. For example, according to an exemplary embodiment, the game manager  25  may determine that a mission has been accomplished once there are a certain number of objects that have been completely selected within a limit time. However, when the time that has elapsed since the start of the game reaches a limit time while the number of target objects that have been completely selected is less than the target score, the game manager  25  may determine that the game is over. 
     According to an exemplary embodiment, the game manager  25  may further determine whether the information providing condition is satisfied on the basis of the provision condition information  32 . An example information providing condition may be a condition where the time that has elapsed since the start of the game exceeds a certain predetermined time, and the gaze position of the player is outside the gameable area. The certain predetermined time may be set as, for example, a time at which there is very little remaining time until the limit time, or an average time required for the player to accomplish the mission. When the game manager  25  determines that the information providing condition is satisfied, the game manager  25  may output to the information provider  27  a request for outputting the to-be-provided information  35 . 
     The game manager  25  may also extract audio information such as sound effects and sound that describes the progress of the game from an audio information storage unit (not illustrated), and may transmit the audio information to the HMD  10  via the input/output unit  23 . 
     The space image output unit  26  may extract the virtual space image information  30  within a field-of-view range around the coordinates indicated by the gaze position information  33 , and may transmit the extracted virtual space image information  30  as an image signal to the HMD  10 . The space image output unit  26  may also display a character corresponding to the player in the virtual space. When the game manager  25  determines that selection of a target object is completed, the space image output unit  26  may change the display form of the target object, which has been completely selected. 
     According to an exemplary embodiment, upon receipt of a request for displaying a hint, which may be output from the game manager  25 , the information provider  27  may read the to-be-provided information  35 . The information provider  27  may output a display corresponding to the to-be-provided information  35  to the display  14 , and may display the output display on a virtual space image. 
     Referring next to  FIG. 2 , an object selecting function performed by the game processing apparatus  20  will be described. 
     The gaze position identifying unit  24  may receive, from the HMD  10 , a detection signal obtained by the sensor  12 , and may identify the position and direction of the head of a player  101  in accordance with the detection signal. Specifically, the gaze position identifying unit  24  may calculate the position and direction of the head as a position in three-axis directions and an angle around each axis. This may include, for example, determining the position of the head along the X-axis along a horizontal direction and a pitch Op of the head indicating a rotation direction around the X-axis, determining the position of the head along the Y-axis along a vertical direction and a yaw Oy of the head indicating a rotation direction around the Y-axis, and determining the position of the head along the Z-axis along a depth direction and a roll Or of the head indicating a rotation direction around the Z-axis. 
     According to an exemplary embodiment, the gaze position identifying unit  24  may identify a gaze position P 1  of the player  101  in the virtual space, on the basis of the calculated position and direction of the head. A method of the related art may be used as a method of identifying the gaze position. For example, the gaze position identifying unit  24  may virtually set a straight line connecting the left eye position and the right eye position, and may set, as a line-of-sight direction D 1 , a direction that extends in a direction orthogonal to the straight line and that crosses the midpoint of the left eye position and the right eye position. The gaze position identifying unit  24  may further identify the intersection between the line-of-sight direction D 1  and an object  102  (or background) as the gaze position P 1 . When a device that detects the eyeball movement or light reflected from the interior of the iris is used as the sensor  12 , the line-of-sight direction may be identified on the basis of the eyeball movement or the reflected light. 
     According to an exemplary embodiment, a gameable area  105  may be provided in the virtual space. The gameable area  105  may be set around a character corresponding to the player. Since the gameable area  105  may include all target objects  103 , the gaze position P 1  may be located in the gameable area  105  when the player gazes at one of the target objects  103  to select that target object  103 . 
     According to an exemplary embodiment, the space image output unit  26  may extract the virtual space image information  30  within a field-of-view range around the gaze position P 1 , and may transmit the extracted virtual space image information  30  as an image signal to the HMD controller  11 . The HMD controller  11  may output an image in accordance with the received virtual space image information  30  to the display  14 . 
     Referring next to  FIG. 3 , a process by which a game may progress will be described. According to an exemplary embodiment, a condition for ending the process may be one of the following: the satisfaction of the mission accomplishing condition, and the elapsed time since the start of the game reaching the limit time. The process may be repeated until this ending condition is satisfied. The elapsed time may be measured by the game manager  25  until the game ends, and may be measured on the basis of a system time (for example, using a clock signal of the CPU). 
     When the game starts, the controller  21  may identify the gaze position of the player (step S 1 ). Specifically, the gaze position identifying unit  24  in the controller  21  may identify the gaze position of the player using the above-mentioned method, and may update the gaze position information  33  with the identified gaze position. 
     Using the gaze position information  33 , the controller  21  may determine whether selection of a target object is completed (step S 2 ). Specifically, the game manager  25  in the controller  21  may read the object information  31  of a target object and the gaze position information  33  from the storage unit  22 , may compare the coordinates of the target object with the gaze position, and may determine whether the gaze position is on the target object. 
     When the gaze position is on the target object, the game manager  25  may measure the gaze time using the system time or the like, and may update the gaze time information  34  with the measured gaze time. When the gaze time reaches a certain predetermined time interval, the game manager  25  may determine that selection is completed. 
     According to an exemplary embodiment, when the gaze position becomes outside the target object while the gaze time has not yet met the appropriate predetermined time interval, the game manager  25  may determine that selection of the target object has not been completed (“NO” in step S 2 ), and may reset the gaze time and return to step S 1 . 
     When the game manager  25  determines that selection of the target object is completed (“YES” in step S 2 ), the game manager  25  may update the selection status of the object information  31  to “selection completed”, and may proceed to step S 3 . At this time, the space image output unit  26  may change the display form of the target object, to reflect that it has been completely selected. 
     When selection of the target object is completed, the controller  21  may determine whether the mission accomplishing condition has been satisfied (step S 3 ). Specifically, the game manager  25  in the controller  21  may refer to the selection status included in the object information  31 , and may determine whether there are a certain number of target objects that have been completely selected within the limit time of the game. This number may be called a “target object target score.” 
     When the number of target objects that have been completely selected is at least the target object target score, the controller  21  may determine that the mission accomplishing condition has been satisfied (“YES” in step S 3 ). This may satisfy the condition for ending the game progressing process, and the game thus may be caused to end. 
     When the number of target objects that have been completely selected is less than the target object target score, the controller  21  may determine that the mission accomplishing condition is not satisfied (“NO” in step S 3 ), and may return to step S 1 . Specifically, when the game manager  25  in the controller  21  determines that the mission accomplishing condition is not satisfied, the game manager  25  may identify the gaze position in step S 1 . 
     Referring next to  FIG. 4 , an exemplary procedure of an information providing process will be described. According to an exemplary embodiment, the process may be a process executed independently and in parallel with the game progressing process. 
     According to an exemplary embodiment, a condition for ending the process may be one of the following: the satisfaction of the mission accomplishing condition, and the time elapsed since the start of the game reaching the limit time before the mission is accomplished. The process may be repeated until this ending condition is satisfied. 
     The controller  21  in the game processing apparatus  20  may determine whether the information providing condition has been satisfied (step S 10 ). Specifically, the game manager  25  in the controller  21  may determine whether the elapsed time has reached a predetermined time interval and the gaze position is outside the gameable area. 
     To do so, the game manager  25  may obtain the amount of elapsed time, and may determine whether the elapsed time has reached a predetermined time interval. When it is determined that the elapsed time has reached the predetermined time interval, the game manager  25  may read the gaze position information  33  and the provision condition information  32  from the storage unit  22 , and may determine whether the gaze position is outside the gameable area. When it is determined that the gaze position is outside the gameable area, the game manager  25  may determine that the information providing condition has been satisfied. 
     When it is determined that the information providing condition has been satisfied (“YES” in step S 10 ), the controller  21  may execute the information provision (step S 11 ). Specifically, according to an exemplary embodiment, the game manager  25  in the controller  21  may output an information provision request to the information provider  27 . Upon receipt of the information provision request, the information provider  27  may read the to-be-provided information  35  from the storage unit  22 , and may output the to-be-provided information  35  to the HMD  10 . 
     In contrast, when the information providing condition has not yet been determined to be satisfied (“NO” in step S 10 ), the controller  21  may repeatedly determine whether the information providing condition has been satisfied (step S 10 ). 
     According to an exemplary embodiment, a process used to provide information may be linked with a process used to progress the game. For example, when selection of a target object is completed in the game progressing process (“YES” in step S 2 ), or when it is determined that the mission accomplishing condition has been satisfied (“YES” in step S 3 ), the elapsed time which is measured in order to determine when information may be provided may be reset. Alternatively, on the basis of the determination that selection of a target object is completed in the information providing process (step S 2 ), the time in which no target object is selected at all after the start of the game may be used as an “elapsed time” value for purposes of determining when information may be provided, rather than the amount of time that has elapsed since the start of the game. The time in which no target object has been selected at all after the start of the game reaching a certain time, and the gaze position being outside the gameable area may serve as the information providing condition. 
     Referring next to  FIGS. 5 and 6 , an image displayed on the display  14  of the HMD  10  during the progress of the game will be described. According to an exemplary embodiment, virtual space images illustrated in  FIGS. 5 and 6  may be schematically illustrated independently of the field-of-view range of the HMD  10 . 
     As illustrated in  FIG. 5 , according to an exemplary embodiment, a virtual space image  110  that is an image based on the virtual space image information  30  and that is around the gaze position may be displayed on the display  14  of the HMD  10 . In the virtual space image  110 , target objects  103  may be displayed in the gameable area  105 . Objects  106  other than the target objects  103  may be displayed in the gameable area  105 . 
     As illustrated in  FIG. 6 , according to an exemplary embodiment, when the gaze position is moved to a position outside the gameable area  105 , an information provision display  111  may be output, which may overlap the virtual space image  110  outside the gameable area  105 . The information provision display  111  may display the details of a hint based on the to-be-provided information  35 . Since the information provision display  111  may be displayed overlapping the virtual space image  110  outside the gameable area  105 , the information provision display  111  may not overlap the target objects  103 . According to an exemplary embodiment wherein the information provision display  111  does not overlap the target objects  103 , information can be provided without obstructing the player in selecting one of the target objects  103 . According to an exemplary embodiment wherein the information provision display  111  is not displayed until the elapsed time exceeds the certain time, the player may not be bothered by frequent information provision. 
     Referring to  FIG. 6 , according to an exemplary embodiment, a moving body  112 , which may appear as a bird moving outside the gameable area  105 , is displayed holding the information provision display  111  where the hint is described. That is, the information provision display  111  may move in accordance with the speed and direction in which the moving body  112  moves. The moving body  112  and the information provision display  111  may be rendered as objects in the virtual space such that their image attributes, such as their lightness and tone, fit the virtual space image  110 . According to such an exemplary embodiment, by having an object in the virtual space hold the information provision display  111 , information can be provided without reducing the loss of a sense of immersion in the virtual space. 
     According to an exemplary embodiment, when the gaze position becomes outside the gameable area like the above case, it may be determined that selection of a target object has not been smoothly performed, and the information provision display  111  may be displayed. In doing so, information can be provided with the appropriate timing for the player. According to an exemplary embodiment, by providing information on the basis of the movement of the gaze position like the above case, potentially immersion-breaking structures, such as, for example, a button for executing information provision, can be omitted. This can reduce the extent to which a sense of immersion in the virtual space may be lost. 
     As has been described above, according to an exemplary embodiment, the following advantageous effects may be obtained: 
     First, since information provision is executed based on the condition that the movement of the gaze position of the player matches the information providing condition, there may be no need to display a button for executing information provision on an image of the virtual space. In doing so, information can be provided while reducing the loss of a sense of immersion in the virtual space. 
     Second, in the above-described first embodiment, information provision may be executed when the gaze position of the player becomes outside the gameable area that includes all target objects. That is, information can be provided when selection of a target object is interrupted, such as when the player is not sure about how to progress the game. In doing so, information provision can be executed with the appropriate timing. 
     Third, according to an exemplary embodiment, the hint may be displayed on the object (moving body) moving in the virtual space described above. Since the player pays attention to a moving thing, attention from the player can be naturally drawn to the hint. 
     Referring next to  FIGS. 4 to 7 , another exemplary embodiment of a virtual image display program, a virtual image display apparatus, and a virtual image display method may be described. 
     According to an exemplary embodiment, an information providing condition may alternatively be that the player has stopped gazing at a target object before completely selecting that target object, and/or may be that the gaze position after the player stops gazing has moved to outside the gameable area. 
     Referring to  FIG. 4 , according to an exemplary embodiment, an information providing process may be described. A condition for ending the process may be that one of the following is satisfied: that the satisfaction of the mission accomplishing condition, and the time elapsed since the start of the game reaching the limit time before the mission is accomplished. The process is repeated until this ending condition is satisfied. 
     The controller  21  in the game processing apparatus  20  may determine whether the information providing condition has been satisfied (step S 10 ). Specifically, the game manager  25  in the controller  21  may read the gaze position information  33  and the object information  31  from the storage unit  22 , and may determine whether the gaze position is on a target object. When the gaze position is not on a target object, the game manager  25  may determine that the information providing condition is not satisfied (“NO” in step S 10 ), and may repeat the determination in step S 10 . 
     When it is determined that the player has gazed at a target object, the game manager  25  may obtain the gaze time, and may determine whether the gaze position has been set to a position outside the gameable area before the gaze time reaches the required time for selecting a target object. When the gaze position is on the target object, the game manager  25  may determine that the information providing condition is not satisfied (“NO” in step S 10 ), and may repeat the determination in step S 10 . 
     However, according to an exemplary embodiment, when the gaze position is moved to outside the gameable area before the gaze time in which the player has continuously gazed at the target object reaches the required time to select the target object, the game manager  25  may provide information (step S 11 ). 
     Referring to  FIGS. 7A and 7B , according to an exemplary embodiment, certain images as may be described may be displayed on the display  14  of the HMD  10  during the progress of the game. Virtual space images illustrated in  FIG. 7  may be schematically illustrated independently of the field-of-view range of the HMD  10 . 
     As illustrated in  FIG. 7A , when the player gazes at a target object  103  displayed on the virtual space image  110 , the space image output unit  26  may display a gauge  120  overlapping the target object  103 . The gauge  120  may display the time elapsed from when the player starts gazing to when the gaze time reaches the certain time. 
     Now, as illustrated in  FIG. 7B , when the gaze position on the target object  103  is moved to outside the gameable area  105 , the information provision display  111  may be output. 
     In  FIG. 7B , according to an exemplary embodiment, the information provision display  111  may be displayed in a direction in which the moving body  112 , which may be, for example, a bird, may move or may be moved. Typical players may tend to pay more attention to the moving body  112  than to a still object. Therefore, according to an exemplary embodiment, displaying the information provision display  111  ahead of the moving body and in the direction in which the moving body  112  is moving may make it easier for the player to recognize the information provision display  111 . According to an exemplary embodiment, the information provision display  111  may be displayed in a still state, which may allow the player to easily recognize the details of the information provision display  111 . 
     As has been described above, according to an exemplary embodiment, a plurality of movements of the player may be defined, which may include, for example, a player stopping gazing at a target object before completely selecting that target object, and the gaze position of the player after the player stops gazing being moved to outside the gameable area. In doing so, the player&#39;s circumstance can be more accurately determined by taking into consideration these multiple movements. 
     According to an exemplary embodiment, the following advantageous effects may be obtained: 
     First, the information providing condition may be that, before the player completes selecting a target object, the gaze position of the player is moved to a position outside the target object and outside the gameable area. Accordingly, information can be provided when the player fails in selecting a target object. In doing so, information provision can be executed with the appropriate timing. 
     Second, according to an exemplary embodiment, the information provision display  111  may be displayed in a direction in which the moving body  112 , which is an object moving in the virtual space, such as a bird, moves. In doing so, information provision can be output without reducing a sense of immersion in the virtual space. 
     Referring next to  FIG. 4 , according to an alternative exemplary embodiment, a virtual image display program, a virtual image display apparatus, and a virtual image display method may be described. 
     According to an exemplary embodiment, the information providing condition may be that, before the player accomplishes the mission, the movement range of a certain body part of the player is moved to outside the reference movement range of the certain body part for selecting a target object. For example, the certain body part of the player may be the head. The reference movement range of the head for selecting a target object may be determined in advance. According to an exemplary embodiment, this may enable the playing of the game without requiring a gameable area to be set. 
     The movement range of the head of the player may indicate the movement range of the head since the start of the game. The movement range of the head of the player may be defined as, for example, the range of pitch θp, yaw θy, and roll θr indicating angular coordinates. The predetermined movement range of the head may be recorded as, for example, part of the provision condition information  32  in the storage unit  22 . 
     When the movement range of the head of the player is narrower than the predetermined reference range for the head of the player, there is a possibility that the range where the player is gazing is too narrow. In contrast, when the movement range of the head of the player is wider than the predetermined reference range, this may indicate that the player has not been able to accomplish the mission, even though the range where the player is gazing is wide enough. This may thus indicate the possibility that the player is not sure about the mission accomplishing condition or the operation method, or that the player has been unable to find a target object. In such a case where the movement range of the head of the player is too narrow or too wide, a hint on the progress of the game may be provided, thereby helping the player to accomplish the mission. 
     Referring to  FIG. 4 , an exemplary embodiment of the information providing process will be described. A condition for ending the process may be one of the following: the satisfaction of the mission accomplishing condition, and the time elapsed since the start of the game reaching the limit time before the mission is accomplished. The process may be repeated until this ending condition is satisfied. 
     The controller  21  in the game processing apparatus  20  may determine whether the information providing condition has been satisfied (step S 10 ). Specifically, the game manager  25  in the controller  21  may calculate the movement range of the head of the player. According to an exemplary embodiment, the history of the movement of the head of the player since the start of the game may be accumulated. The game manager  25  may read the provision condition information  32 , and may determine whether the movement range of the head of the player is within the reference range included in the provision condition information  32 . For example, according to an exemplary embodiment, a range defined for the above-mentioned three rotation directions may be used as the reference range included in the provision condition information  32 . 
     When the movement range of the head of the player has been outside the reference range for at least one rotation direction, the game manager  25  may make a determination that the movement range of the head of the player is outside the reference range. 
     According to an exemplary embodiment, when it is determined that the information providing condition is not satisfied (“NO” in step S 10 ), the controller  21  may repeat the determination about whether the information providing condition has been satisfied (step S 10 ). Specifically, the game manager  25  in the controller  21  may determine that the information providing condition is not satisfied when the movement range of the head of the player becomes outside the reference range for at least one rotation direction, and may repeat the determination in step S 10 . 
     According to an exemplary embodiment, when it is determined that the information providing condition has been satisfied (“YES” in step S 10 ), the controller  21  may execute information provision (step S 11 ). Specifically, the game manager  25  may determine that the information providing condition has been satisfied when the movement range of the head of the player is within the reference range for all the rotation directions, and may then execute information provision. 
     According to an exemplary embodiment, the following advantageous effects may be obtained: 
     According to an exemplary embodiment, the information providing condition may be that the movement range of the head of the player has become a range outside the predetermined reference range. Accordingly, the information providing condition may be satisfied when the range in which the player gazes is too wide, or alternatively when the range in which the player gazes is too narrow. This may ensure that information provision can be executed with the appropriate timing. 
     Referring next to  FIG. 4 , another exemplary embodiment of a virtual image display program, a virtual image display apparatus, and a virtual image display method will be described. 
     According to an exemplary embodiment, an information providing condition may be that the movement of the certain body part of the player corresponds to a predetermined movement. For example, the certain body part of the player may be the head. For example, according to an exemplary embodiment, a predetermined movement of the head that may act as an information providing condition may be an unstable and peculiar movement different from the normal movement of the head of the player when the player is selecting a target object. Examples of the predetermined movement may include movements that indicate that the player is nervous or in a hurry. 
     The movement of the head of the player may be represented by, for example, the average movement speed of the head of the player, the maximum or minimum movement speed of the head of the player, the number of conversions in the movement direction per unit time, or the like. The movement speed of the head of the player may be calculated by the controller  21  in the game processing apparatus  20  from the identified position and direction of the head of the player. The provision condition information  32  may include a predetermined movement of the head of the player, which may be determined in advance. Specifically, the provision condition information  32  may include a predetermined peculiar movement of the head, which may be different from the movement for selecting a target object. 
     Referring to  FIG. 4 , an exemplary embodiment of the information providing process may be described. A condition for ending the process may be one of the following: the satisfaction of the mission accomplishing condition, and the time elapsed since the start of the game reaching the limit time before the mission is accomplished. The process may be repeated until this ending condition is satisfied. 
     The controller  21  in the game processing apparatus  20  may determine whether the information providing condition has been satisfied (step S 10 ). Specifically, the game manager  25  in the controller  21  may calculate the movement of the head of the player, such as the average movement speed of the head of the player, using the position and direction of the head of the player, which may be calculated in accordance with a detection signal received from the sensor  12 . The game manager  25  may read the provision condition information  32 , and may determine whether the calculated movement of the head of the player corresponds to the predetermined movement of the head of the player, which may be included in the provision condition information  32 . 
     According to an exemplary embodiment, when it is determined that the information providing condition has not been satisfied (“NO” in step S 10 ), the controller  21  may repeat the determination of whether the information providing condition has been satisfied (step S 10 ). Specifically, the game manager  25  in the controller  21  may determine that the information providing condition is not satisfied when the movement of the head of the player does not correspond to the predetermined movement included in the provision condition information  32 , and may repeat the determination in step S 10 . 
     In contrast, when it is determined that the information providing condition has been satisfied (“YES” in step S 10 ), the controller  21  may execute information provision (step S 11 ). Specifically, the game manager  25  in the controller  21  may determine that the information providing condition is satisfied when the movement of the head of the player corresponds to the predetermined movement included in the provision condition information  32 , and may then execute information provision. 
     As has been described above, according to an exemplary embodiment, the following advantageous effects may be obtained: 
     According to an exemplary embodiment, the information providing condition may be that the movement of the head of the player corresponds to a predetermined movement recorded in the storage unit  22 . Accordingly, the information providing condition may be satisfied when the player makes such a movement, for example, as if the player is not sure about how to progress the game. According to such an embodiment, information provision can be executed with the appropriate timing. 
     Further exemplary embodiments of the invention may also be understood. For example, in some embodiments, the gameable area may be an area that includes all target objects. However, in other exemplary embodiments, it may only be necessary for the gameable area to be an area that at least includes a certain number of target objects for accomplishing the mission. 
     According to some exemplary embodiments, the set of displayed objects may include target objects that are selectable and objects that are not selectable. However, according to other exemplary embodiments, all objects displayed in the virtual space may be selectable objects. 
     According to some exemplary embodiments, the mission accomplishing condition of the game may be that there are a certain number of target objects that are completely selected within the limit time of the game. Alternatively, the mission accomplishing condition may be another condition or multiple other conditions. For example, the mission accomplishing condition may be satisfied when the timing for selecting a target object matches preset timing, or may be satisfied when the same target object is selected a certain number of times. 
     According to an exemplary embodiment, the information provision display  111  may be displayed as paper held by a bird which is a moving body, and this paper may also be moved in accordance with the moving body. Alternatively, the information provision display  111  may be a moving body other than a bird, such as a vehicle including an air plane, a creature such as a butterfly, or a fallen leaf, which may move in the virtual space. Alternatively, hints on the progress of the game may be written on these moving bodies, or these moving bodies may hold the information provision display  111 . Alternatively, paper falling in the virtual space may be a moving body, and a hint may be displayed on that paper. 
     According to an exemplary embodiment, the information provision display  111  may not be displayed unless the elapsed time exceeds the certain time. Alternatively, the information provision display  111  may be displayed simply when the gaze position is moved to outside the gameable area. 
     According to an exemplary embodiment, the information provision display  111  may be displayed on condition that the gaze position of the player moves outside the gameable area before the player completes selecting a target object. Alternatively, the information provision display  111  may be displayed when the gaze position of the player, which is within the gameable area, is shifted to being outside a target object before the player completes selecting the target object. 
     According to an exemplary embodiment, the movement range of the head may be represented by three rotation directions. However, according to other exemplary embodiments, the movement range of the head may be represented by variables other than these mentioned above. For example, the movement range of the head may be represented as, for example, “90 degrees to the left and 90 degrees to the right” and “30 degrees to the top and 30 degrees to the bottom” with reference the position and direction of the head of the player facing horizontally. 
     According to an exemplary embodiment, when the movement range of the head of the player becomes shifted to outside the reference range in at least one rotation direction, it may be determined that the movement range of the head of the player is outside the reference range. Alternatively, it may be determined that the movement range of the head of the player is outside the reference range when the movement range of the head of the player becomes outside the reference range for all rotation directions. 
     According to an exemplary embodiment, the information providing condition may be that the movement range of the head of the player has become shifted to outside the reference movement range of the head for selecting a target object. According to another exemplary embodiment, the information providing condition may be that the movement of the head of the player corresponds to a particular predetermined movement. The term “movement of the head” in these information providing conditions may be replaced with the term “gaze position”. That is, according to an exemplary embodiment, the information providing condition may be that the movement range of the gaze position of the player has become outside the reference movement range of the gaze position for selecting a target object. According to another exemplary embodiment, the information providing condition may be that the movement of the gaze position of the player corresponds to a particular predetermined movement. 
     According to an exemplary embodiment, a hint on the progress of the game may be displayed as information provision. However, according to other exemplary embodiments, other types of information may be provided. For example, information such as menu items, score, the character&#39;s status, the time left for continuing the game, the progression stage of the game, or the like may be provided. 
     According to an exemplary embodiment, the information providing condition may include multiple information providing conditions described above. For example, an information providing condition may be either of the following conditions: “when the time elapsed since the start of the game is at least some predetermined time value, the gaze position of the player is outside a gameable area set in the virtual space” and “a range including the head movement becomes outside the reference range before the player accomplishes the mission”. Alternatively, the information providing condition may include the condition of “the head movement corresponds to the certain movement”. Other combinations of information providing conditions may also be understood. Even in doing so, information can be provided while reducing the loss of a sense of immersion in the virtual space. 
     According to some exemplary embodiments, information may be provided by outputting the information provision display  111  to the display  14 . Alternatively, information may be provided when the information providing condition is satisfied by outputting sound regarding the details of a hint or by outputting a warning sound. 
     According to an exemplary embodiment, the HMD controller  11  may calculate the position and direction of the head on the basis of a detection signal obtained by the sensor  12 . According to another exemplary embodiment, the HMD  10  may additionally perform some of the functions of the game processing apparatus  20 . 
     In some exemplary embodiments, the gaze position of the player may be calculated on the basis of the position and direction of the head of the player. In other exemplary embodiments, the line-of-sight direction may be calculated on the basis of the positions of the pupils, and the gaze position may be identified from the line-of-sight direction. Alternatively, the line-of-sight direction may be calculated on the basis of the position and direction of the nose or the position and direction of the mouth, for example, and the gaze position may be identified from the line-of-sight direction. The direction of the nose or mouth may be defined as a direction from the back of the head to the nose or mouth, for example. 
     In some exemplary embodiments, the virtual image display apparatus may be implemented as a game processing apparatus. In other exemplary embodiments, the virtual image display apparatus may be applied to virtual reality systems for other applications. For example, the virtual image display apparatus may be applied to various types of simulations for driving, job training, or the like, trainings in medical fields, monitoring products, and movie or music appreciation. Even when the virtual image display apparatus is applied to virtual reality systems for applications other than games, information can be provided while reducing the loss of the player&#39;s (user&#39;s) sense of immersion in the virtual space.