Patent Publication Number: US-9833705-B2

Title: Storage medium storing information processing program, information processing apparatus and information processing method

Description:
CROSS REFERENCE OF RELATED APPLICATION 
     The disclosure of Japanese Patent Application No. 2009-112465 is incorporated herein by reference. 
     BACKGROUND OF THE INVENTION 
     Field of the Invention 
     The present invention relates to a storage medium storing an information processing program, an information processing apparatus, and an information processing method. More specifically, the present invention relates to a storage medium storing an information processing program, an information processing apparatus, and an information processing method which performs an operation by utilizing a load value indicating a load of a user. 
     Description of the Related Art 
     One example of the related art is disclosed in a Japanese Patent Application Laid-Open No. 2008-264195 [A63F 13/04, A63F 13/00] (Document 1) laid-open on Nov. 6, 2008. In the game apparatus of the Document 1, a player rides the legs on a support plate of a game controller which includes four load sensors, and a load value detected by the four load sensors is input as operation data. Accordingly, in the game apparatus, the game processing is executed on the basis of the load value input as operation data. 
     However, in the game apparatus shown in the Document 1, the game processing is executed only on the basis of the variation of the load value input as the operation data, so that the game relatively becomes simple. Thus, there is room for improvement of execution of many kinds of processing according to a variation of an input operation by a load value and enrichment of an interest to the game. 
     SUMMARY OF THE INVENTION 
     Therefore, it is a primary object of the present invention is to provide a novel storage medium storing an information processing program, a novel information processing apparatus, and a novel information processing method. 
     Another object of the present invention is to provide a storage medium storing an information processing program, an information processing apparatus, and an information processing method which are able to execute many kinds of processing in correspondence with a variation of an input operation by utilizing a load value. 
     The present invention employs following features in order to solve the above-described problems. It should be noted that reference numerals and the supplements inside the parentheses show one example of a corresponding relationship with the embodiments described later for easy understanding of the present invention, and do not limit the present invention. 
     A first invention is a storage medium storing an information processing program, the information processing program causes a computer to execute: a load value acquiring step for acquiring a load value indicating a load of a user on the basis of a signal from a load detecting apparatus, a cycle judging step for judging a cycle of a load variation of the user on the basis of the load value acquired by the load value acquiring step, and an information processing step for executing predetermined information processing on the basis of the cycle judged by the cycle judging step. 
     In the first invention, an information processing program causes a computer to execute a load value acquiring step ( 40 , S 3 , S 7 ), a cycle judging step ( 40 , S 121 , S 131 ), and an information processing step ( 40 , S 15 , S 17 , S 21 , S 23 , S 57 , S 75 , S 77 ). The load value acquiring step acquires a load value indicating a load of a user on the basis of a signal from a load detecting apparatus ( 36 ). The cycle judging step judges a cycle of a load variation of the user on the basis of the load value acquired by the load value acquiring step. The information processing step executes predetermined information processing on the basis of the cycle judged by the cycle judging step. 
     According to the first invention, the predetermined information processing is executed on the basis of the cycle of the load variation of the user, and therefore, it is possible to execute many kinds of processing according to the variation of the input operations by the load values. 
     A second invention is according to the first invention, and the information processing step executes at least first information processing or second information processing different from the first information processing on the basis of the cycle judged by the cycle judging step. 
     In the second invention, the information processing step executes at leas first information processing (S 21 , S 23 , S 75 , S 77 ) or second information processing (S 15 , S 17 , S 75 , S 77 ) different from the first information processing on the basis of the cycle judged by the cycle judging step. 
     According to the second invention, at least the two different information processing are performed on the basis of the cycle of the load variation of the user, so that it is possible to execute many kinds of processing according to the variation of the input operations by the load values. 
     A third invention is according to the second invention, and the information processing program causes a computer to further execute a condition determining step for determining whether or not the cycle judged by the cycle judging step satisfies a predetermined condition, and the information processing step executes the first information processing when the condition determining step determines that the cycle satisfies the predetermined condition, and executes the second information processing when the condition determining step determines that the cycle does not satisfy the predetermined condition. 
     In the third invention, an information processing program causes a computer to further execute a condition determining step ( 40 , S 137 ). The condition determining step determines whether or not the cycle judged by the cycle judging step satisfies a predetermined condition. The information processing step executes the first information processing when the condition determining step determines that the cycle satisfies the predetermined condition (“YES” in S 137 ), and executes the second information processing when the condition determining step determines that the cycle does not satisfy the predetermined condition (“NO” in S 137 ). 
     According to the third invention, it is possible to execute different information processing by merely determining whether or not the cycle of the load variation of the user satisfies the predetermined condition. 
     A fourth invention is according to the third invention, and the condition determining step determines whether or not a cycle of the cycle judged by the cycle judging step is equal to or more than a first predetermined value, and the information processing step executes the second information processing when the condition determining step determines that the frequency is equal to or more than the first predetermined value. 
     In the fourth invention, the condition determining step determines whether or not a frequency of the cycle judged by the cycle judging step is equal to or more than a first predetermined value. The information processing step executes the second information processing when the condition determining step determines that the frequency is equal to or more than the first predetermined value (“YES” in S 137 ). 
     According to the fourth invention, it is possible to execute the second information processing by merely determining whether or not the frequency of the cycle of the load variation of the user is equal to or more than the threshold value. 
     A fifth invention is according to the third invention, and the cycle judging step judges the cycle on the basis of a frequency spectrum of the load variation of the user, the condition determining step determines whether or not the frequency of the cycle judged by the cycle judging step is a second predetermined value and a power spectrum of a frequency larger than the frequency is equal to or more than a maximum value of a spectrum noise, and the information processing step executes the second information processing when the condition determining step determines that the frequency is a second predetermined value and a power spectrum of a frequency larger than the frequency is equal to or more than a maximum value of a spectrum noise. 
     In the fifth invention, the cycle judging step, for example, judges the cycle on the basis of a frequency spectrum of the load variation of the user. Furthermore, the condition determining step determines whether or not the frequency of the cycle judged by the cycle judging step is a second predetermined value and a power spectrum of a frequency larger than the frequency is equal to or more than a maximum value of a spectrum noise. The information processing step executes the second information processing when the condition determining step determines that the frequency is a second predetermined value and a power spectrum of a frequency larger than the frequency is equal to or more than a maximum value of a spectrum noise (“YES” in S 137 ). 
     According to the fifth invention, in a case that the cycle is judged on the basis of the frequency spectrum of the load variation of the user as well, by merely comparing the magnitude of the power spectrum with the maximum value of the spectrum noise, it is possible to execute the second information processing. 
     A sixth invention is according to the first invention, and the information processing program causes a computer to further execute a movement controlling step for controlling a magnitude of at least a moving distance or a moving velocity of an object displayed on a display screen on the basis of the load value acquired by the load acquiring step. 
     In the sixth invention, the information processing program causes a computer to further execute a movement controlling step ( 40 , S 25 -S 35 , S 36 , S 39 , S 93 -S 107 ). The movement controlling step controls a magnitude of at least a moving distance or a moving velocity of an object displayed on a display screen on the basis of the load value of the user. That is, the parameter as to the moving distance or the moving velocity is decided. 
     According to the sixth invention, the magnitude of the moving distance or the moving amount of the object is decided on the basis of the load value, and therefore, it is possible to execute a variety of processing in correspondence with the load value of the user, and control the movement of the object in correspondence with the load value. 
     A seventh invention is according to the sixth invention, and the movement controlling step increases the moving distance or the moving velocity of the object as an amplitude of the variation of the load value acquired by the load value acquiring step is large. 
     In the seventh invention, the movement controlling step increases the moving distance or the moving velocity of the object as an amplitude of the variation of the load value acquired by the load value acquiring step is large, that is, as the load variation of the user is large. 
     According to the seventh invention, as the load variation of the user is large, the moving distance or the moving velocity of the object is increased, and therefore, it is possible to control the movement of the object in accordance with the motion of the user. 
     An eighth invention is according to the sixth invention, and the movement controlling step increases the moving distance or the moving velocity of the object when the load value acquired by the load acquiring step is less than a predetermined value. 
     In the eighth invention, for example, the movement controlling step increases the moving distance or the moving velocity of the object when the load value acquired by the load acquiring step is less than a predetermined value. That is, when an unweight is made, the moving distance or the moving velocity of the object is increased. 
     According to the eighth invention, similar to the sixth invention, it is possible to execute a variety of processing in accordance with the load value of the user, and control the movement of the object in accordance with the load value. 
     A ninth invention is according to the sixth invention, and the movement controlling step increases the moving distance or the moving velocity of the object when the cycle of the variation of the load value acquired by the load acquiring step is long. 
     In the ninth invention, for example, the movement controlling step increases the moving distance or the moving velocity when the cycle of the variation of the load value acquired by the load acquiring step is long. That is, even when the user performs the same motion, if the motion is made largely, the moving distance or the moving velocity of the object is also increased in associated therewith. 
     According to the ninth invention, similar to the sixth invention, it is possible to execute a variety of processing in correspondence with the load value of the user, and control the movement of the object in correspondence with the load value. 
     A tenth invention is according to the sixth invention, and the information processing program causes a computer to further execute a barycentric position detecting step for detecting a barycentric position of the user on a two-dimensional plane on the basis of a signal from the load detecting apparatus, and the movement controlling step controls a moving direction of the object on the basis the barycentric position detected by the barycentric position detecting step. 
     In the tenth invention, the information processing program causes a computer to further execute a barycentric position detecting step ( 40 , S 9 ). The barycentric position detecting step detects a barycentric position of the user on a two-dimensional plane on the basis of a signal from the load detecting apparatus. The movement controlling step controls a moving direction of the object on the basis of the barycentric position detected by the barycentric position detecting step. That is, the parameter as to the moving direction is decided. 
     According to the tenth invention, the moving direction of the object is controlled according to the baricentric position, so that it is possible to control the moving direction of the object as well as the moving distance or the moving velocity depending on how to impose the load. 
     An eleventh invention is according to the tenth invention, and the object moves in the virtual space, and the movement controlling step decides the moving direction of the object according to different deciding processing between when the object moves to a predetermined direction and when the object moves to a direction other than the direction. 
     In the eleventh invention, the object moves in the virtual space, and the movement controlling step decides the moving direction of the object according to different deciding method between when the object moves to a predetermined direction (“YES” in S 35 ) and when the object moves to a direction other than the direction (“NO” in S 35 ). 
     According to the eleventh invention, the deciding method of the moving direction by the barycentric position is changed according to the moving direction of the object, so that it is possible to enrich a variation of the movement of the object. 
     A twelfth invention is according to the eleventh invention, and the movement controlling step decides a first moving direction as a moving direction of the object on the basis of the barycentric position detected by the barycentric position detecting step in a case that the object moves to the predetermined direction, and decides a second moving direction as a moving direction of the object on the basis of the barycentric position detected by the barycentric position detecting step in a case that the object moves to the direction other than the predetermined direction. 
     In the twelfth invention, for example, the movement controlling step decides a first moving direction as a moving direction of the object on the basis of the barycentric position detected by the barycentric position detecting step (S 36 ) in a case that the object moves to the predetermined direction (“YES” in S 35 ), and decides a second moving direction as a moving direction of the object on the basis of the barycentric position detected by the barycentric position detecting step (S 39 ) in a case that the object moves to the direction other than the predetermined direction (“NO” in S 35 ). 
     According to the twelfth invention, similar to the eleventh invention, it is possible to enrich a variation of the movement of the object. 
     A thirteenth invention is according to the first invention, and the information processing step changes at least a display manner of the object displayed on the display screen on the basis of the cycle judged by the cycle judging step. 
     In the thirteenth invention, the information processing step changes at least a display manner of the object displayed on the display screen on the basis of the cycle judged by the cycle judging step. 
     According to the thirteenth invention, the display manner of the object is changed on the basis of the cycle of the load value, and therefore, it is possible to execute many kinds of processing according to the variation of the input operations by the load values. 
     A fourteenth invention is according to the thirteenth invention, and the object is a moving image object, and the information processing step displays the moving image object on the display screen by a different animation on the basis of the cycle judged by the cycle judging step. 
     In the fourteenth invention, the object is a moving image object. The information processing step displays the moving image object on the display screen by a different animation on the basis of the cycle judged by the cycle judging step. 
     According to the fourteenth invention, it is possible to display the moving image object by a different animation in accordance with a variation of the input operations by the load values. 
     A fifteenth invention is according to the fourteenth invention, and the information processing step changes an updating velocity of an animation frame on the basis of the cycle judged by the cycle judging step and a frame number of the animation frame constructing of the animation. 
     In the fifteenth invention, the information processing step changes an updating velocity of an animation frame on the basis of the cycle judged by the cycle judging step and a frame number of the animation frame constructing of the animation 
     According to the fifteenth invention, by changing the updating velocity of the animation frame, it is possible to synchronize the cycle of the load value with the animation. 
     A sixteenth invention is according to the first invention, and the information processing program causes a computer to further execute a ratio calculating step for calculating a ratio of the load value acquired by the load value acquiring step to a body weight value of the user, and the cycle judging step judges a cycle as to the variation of the ratio calculated by the ratio calculating step. 
     In the sixteenth invention, the information processing program causes a computer to further execute a ratio calculating step ( 40 , S 91 ). The ratio calculating step calculates a ratio of the load value to the body weight value of the user. The cycle judging step judges a cycle as to the variation of the ratio calculated by the ratio calculating step. 
     According to the sixteenth invention, a cycle of the ratio of the load value to the body weight value of the user is calculated to thereby judge the cycle, capable of absorbing the difference in the body weight between the users. 
     A seventeenth invention is an information processing apparatus and comprises a load value acquiring means for acquiring a load value indicating a load of a user on the basis of a signal from a load detecting apparatus, a cycle judging means for judging a cycle of a load variation of the user on the basis of the load value acquired by the load value acquiring means, and an information processing means for executing predetermined information processing on the basis of the cycle judged by the cycle judging means. 
     In the seventeenth invention as well, similar to the first invention, it is possible to execute many kinds of processing according to the variation of the input operations by the load values. 
     An eighteenth invention is an information processing method of an information processing apparatus, and following steps of: (a) acquiring a load value indicating a load of a user on the basis of a signal from a load detecting apparatus, (b) judging a cycle of a load variation of the user on the basis of the load value acquired by step (a), and (c) executing predetermined information processing on the basis of the cycle judged by the step (b). 
     In the eighteenth invention, similar to the first invention, it is possible to execute many kinds of processing according to the variation of the input operations by the load values. 
     The above described objects and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an illustrative view showing one embodiment of a game system of the present invention; 
         FIG. 2  is a block diagram showing an electric configuration of the game system shown in  FIG. 1 ; 
         FIG. 3  is an illustrative view showing an appearance of a controller shown in  FIG. 1 ; 
         FIG. 4  is a block diagram showing an electric configuration of the controller shown in  FIG. 3 ; 
         FIG. 5  is an illustrative view showing an appearance of a load controller shown in  FIG. 1 ; 
         FIG. 6  is a cross-sectional view of the load controller shown in  FIG. 5 ; 
         FIG. 7  is a block diagram showing an electric configuration of the load controller shown in  FIG. 5 ; 
         FIG. 8  is an illustrative view showing a situation in which a virtual game is played by utilizing the controller and the load controller shown in  FIG. 1 ; 
         FIG. 9  is an illustrative view showing viewing angles of markers and the controller shown in  FIG. 1 ; 
         FIG. 10  is an illustrative view showing one example of an imaged image including object images; 
         FIG. 11  is an illustrative view showing one example of a game screen to be displayed on a monitor shown in  FIG. 1 ; 
         FIG. 12  is an illustrative view showing an example of a motion of a player when the virtual game of this embodiment is played; 
         FIG. 13  is a graph indicating a time variation of a weight ratio which is detected when the player performs a large-flapping motion as shown in  FIG. 12(A)  and a frequency spectrum of it; 
         FIG. 14  is a graph indicating a time variation of a weight ratio and a frequency spectrum which is detected when the player performs a small-flapping motion as shown in  FIG. 12(B)  and a frequency spectrum of it; 
         FIG. 15  is a graph indicating a time variation of a weight ratio which is detected when the player performs bending and stretching exercises and a frequency spectrum of it; 
         FIG. 16  is an illustrative view showing a barycentric position of the player detected by the load controller and a direction of a player object corresponding thereto; 
         FIG. 17  is an illustrative view showing a direction of the player object except when the player object is falling in correspondence with the barycentric position of the player detected by the load controller; 
         FIG. 18  is an illustrative view showing a direction of the player object when the player object is falling in correspondence with the barycentric position of the player detected by the load controller; 
         FIG. 19  is an illustrative view showing a part of an animation frame as to the player object; 
         FIG. 20  is an illustrative view showing an example of a memory map of a main memory shown in  FIG. 2 ; 
         FIG. 21  is an illustrative view showing a detailed content of a data memory area shown in  FIG. 20 ; 
         FIG. 22  is a flowchart showing a part of game entire processing by the CPU shown in  FIG. 2 ; 
         FIG. 23  is a flowchart being sequel to  FIG. 22  and showing another part of the game entire processing by the CPU shown in  FIG. 2 ; 
         FIG. 24  is a flowchart being sequel to  FIG. 23  and showing a still another part of the game entire processing by the CPU shown in  FIG. 2 ; 
         FIG. 25  is a flowchart being sequel to  FIG. 24  and showing a farther part of the game entire processing by the CPU shown in  FIG. 2 ; 
         FIG. 26  is a flowchart showing a part of a motion judging processing by the CPU shown in  FIG. 2 ; 
         FIG. 27  is a flowchart being sequel to  FIG. 26  and showing another part of the motion judging processing by the CPU shown in  FIG. 2 ; 
         FIG. 28  is a flowchart being sequel to  FIG. 27  and showing still another part of the motion judging processing by the CPU shown in  FIG. 2 ; 
         FIG. 29  is a flowchart showing a part of synchronizing processing by the CPU shown in  FIG. 2 ; 
         FIG. 30  is a flowchart showing another part of the synchronizing processing by the CPU shown in  FIG. 2 ; and 
         FIG. 31  is a flowchart being sequel to  FIG. 29  and  FIG. 30 , and showing a still another part of the synchronizing processing by the CPU shown in  FIG. 2 . 
     
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring to  FIG. 1 , a game system  10  of one embodiment of the present invention includes a video game apparatus (hereinafter, simply referred to as “game apparatus”)  12 , a controller  22  and a load controller  36 . Although illustration is omitted, the game apparatus  12  of this embodiment is designed such that it can be connected to four controllers ( 22 ,  36 ) at the maximum. Furthermore, the game apparatus  12  and the respective controllers ( 22 ,  36 ) are connected in a wireless manner. The wireless communication is executed according to a Bluetooth (registered trademark) standard, for example, but may be executed by other standards such as infrared rays, a wireless LAN. 
     The game apparatus  12  includes a roughly rectangular parallelepiped housing  14 , and the housing  14  is furnished with a disk slot  16  on a front surface. An optical disk  18  as one example of an information storage medium storing game program, etc. as one example of an information processing program is inserted from the disk slot  16  to be loaded into a disk drive  54  (see  FIG. 2 ) within the housing  14 . Around the disk slot  16 , an LED and a light guide plate are arranged so as to be light on or off in accordance with various processing. 
     Furthermore, on a front surface of the housing  14  of the game apparatus  12 , a power button  20   a  and a reset button  20   b  are provided at the upper part thereof, and an eject button  20   c  is provided below them. In addition, a connector cover for external memory card  28  is provided between the reset button  20   b  and the eject button  20   c , and in the vicinity of the disk slot  16 . Inside the connector cover for external memory card  28 , an connector for memory card  62  (see  FIG. 2 ) is provided, through which an external memory card (hereinafter simply referred to as a “memory card”) not shown is inserted. The memory card is employed for loading the game program, etc. read from the optical disk  18  to temporarily store it, storing (saving) game data (result data or proceeding data of the game) of the game played by means of the game system  10 , and so forth. It should be noted that storing the game data described above may be performed on an internal memory, such as a flash memory  44  (see  FIG. 2 ) inside the game apparatus  12  in place of the memory card. Also, the memory card may be utilized as a backup memory of the internal memory. 
     It should be noted that a general-purpose SD card can be employed as a memory card, but other general-purpose memory cards, such as MemoryStick, Multimedia Card (registered trademark) can be employed. 
     The game apparatus  12  has an AV cable connector  58  (see  FIG. 2 ) on the rear surface of the housing  14 , and by utilizing the AV cable connector  58 , a monitor  34  and a speaker  34   a  are connected to the game apparatus  12  through an AV cable  32   a . The monitor  34  and the speaker  34   a  are typically a color television receiver, and through the AV cable  32   a , a video signal from the game apparatus  12  is input to a video input terminal of the color television, and a sound signal from the game apparatus  12  is input to a sound input terminal. Accordingly, a game image of a three-dimensional (3D) video game, for example, is displayed on the screen of the color television (monitor)  34 , and stereo game sound, such as a game music, a sound effect, etc. is output from right and left speakers  34   a . Around the monitor  34  (on the top side of the monitor  34 , in this embodiment), a marker unit  34   b  including two infrared ray LEDs (markers)  340   m  and  340   n  is provided. The marker unit  34   b  is connected to the game apparatus  12  through a power source cable  32   b . Accordingly, the marker unit  34   b  is supplied with power from the game apparatus  12 . Thus, the markers  340   m  and  340   n  emit lights ahead of the monitor  34 . 
     Furthermore, the power of the game apparatus  12  is applied by means of a general AC adapter (not illustrated). The AC adapter is inserted into a standard wall socket for home use, and the game apparatus  12  transforms the house current (commercial power supply) to a low DC voltage signal suitable for driving. In another embodiment, a battery may be utilized as a power supply. 
     In the game system  10 , a user or a player turns the power of the game apparatus  12  on for playing the game (or applications other than the game). Then, the user selects an appropriate optical disk  18  storing a program of a video game (or other applications the player wants to play), and loads the optical disk  18  into the disk drive  54  of the game apparatus  12 . In response thereto, the game apparatus  12  starts to execute a video game or other applications on the basis of the program recorded in the optical disk  18 . The user operates the controller  22  in order to apply an input to the game apparatus  12 . For example, by operating any one of the operating buttons of the input means  26 , a game or other application is started. Besides the operation on the input means  26 , by moving the controller  22  itself, it is possible to move a moving image object (player object) in different directions or change the perspective of the user (camera position) in a 3-dimensional game world. 
       FIG. 2  is a block diagram showing an electric configuration of the video game system  10  shown in  FIG. 1  embodiment. Although illustration is omitted, respective components within the housing  14  are mounted on a printed board. As shown in  FIG. 2 , the game apparatus  12  has a CPU  40 . The CPU  40  functions as a game processor. The CPU  40  is connected with a system LSI  42 . The system LSI  42  is connected with an external main memory  46 , a ROM/RTC  48 , a disk drive  54 , and an AV IC  56 . 
     The external main memory  46  is utilized as a work area and a buffer area of the CPU  40  by storing programs like a game program, etc. and various data. The ROM/RTC  48 , which is a so-called boot ROM, is incorporated with a program for activating the game apparatus  12 , and is provided with a time circuit for counting a time. The disk drive  54  reads program data, texture data, etc. from the optical disk  18 , and writes them in an internal main memory  42   e  described later or the external main memory  46  under the control of the CPU  40 . 
     The system LSI  42  is provided with an input-output processor  42   a , a GPU (Graphics Processor Unit)  42   b , a DSP (Digital Signal Processor)  42   c , a VRAM  42   d  and an internal main memory  42   e , and these are connected with one another by internal buses although illustration is omitted. 
     The input-output processor (I/O processor)  42   a  executes transmitting and receiving data and executes downloading of the data. Reception and transmission and download of the data are explained in detail later. 
     The GPU  42   b  is made up of a part of a drawing means, and receives a graphics command (construction command) from the CPU  40  to generate game image data according to the command. Additionally, the CPU  40  applies an image generating program required for generating game image data to the GPU  42   b  in addition to the graphics command. 
     Although illustration is omitted, the GPU  42   b  is connected with the VRAM  42   d  as described above. The GPU  42   b  accesses the VRAM  42   d  to acquire data (image data: data such as polygon data, texture data, etc.) required to execute the construction command. Additionally, the CPU  40  writes image data required for drawing to the VRAM  42   d  via the GPU  42   b . The GPU  42   b  accesses the VRAM  42   d  to create game image data for drawing. 
     In this embodiment, a case that the GPU  42   b  generates game image data is explained, but in a case of executing an arbitrary application except for the game application, the GPU  42   b  generates image data as to the arbitrary application. 
     Furthermore, the DSP  42   c  functions as an audio processor, and generates audio data corresponding to a sound, a voice, music, or the like to be output from the speaker  34   a  by means of the sound data and the sound wave (tone) data stored in the internal main memory  42   e  and the external main memory  46 . 
     The game image data and audio data generated as described above are read by the AV IC  56 , and output to the monitor  34  and the speaker  34   a  via the AV connector  58 . Accordingly, a game screen is displayed on the monitor  34 , and a sound (music) necessary for the game is output from the speaker  34   a.    
     Furthermore, the input-output processor  42   a  is connected with a flash memory  44 , a wireless communication module  50  and a wireless controller module  52 , and is also connected with an expansion connector  60  and a connector for memory card  62 . The wireless communication module  50  is connected with an antenna  50   a , and the wireless controller module  52  is connected with an antenna  52   a.    
     The input-output processor  42   a  can communicate with other game apparatuses and various servers to be connected to a network via a wireless communication module  50 . It should be noted that it is possible to directly communicate with another game apparatus without going through the network. The input-output processor  42   a  periodically accesses the flash memory  44  to detect the presence or absence of data (referred to as data to be transmitted) being required to be transmitted to a network, and transmits it to the network via the wireless communication module  50  and the antenna  50   a  in a case that data to be transmitted is present. Furthermore, the input-output processor  42   a  receives data (referred to as received data) transmitted from another game apparatuses via the network, the antenna  50   a  and the wireless communication module  50 , and stores the received data in the flash memory  44 . If the received data does not satisfy a predetermined condition, the reception data is abandoned as it is. In addition, the input-output processor  42   a  can receive data (download data) downloaded from the download server via the network, the antenna  50   a  and the wireless communication module  50 , and store the download data in the flash memory  44 . 
     Furthermore, the input-output processor  42   a  receives input data transmitted from the controller  22  and the load controller  36  via the antenna  52   a  and the wireless controller module  52 , and (temporarily) stores it in the buffer area of the internal main memory  42   e  or the external main memory  46 . The input data is erased from the buffer area after being utilized in game processing by the CPU  40 . 
     In this embodiment, as described above, the wireless controller module  52  makes communications with the controller  22  and the load controller  36  in accordance with Bluetooth standards. 
     Furthermore, for the sake of the drawings,  FIG. 2  collectively shows the controller  22  and the load controller  36 . 
     In addition, the input-output processor  42   a  is connected with the expansion connector  60  and the connector for memory card  62 . The expansion connector  60  is a connector for interfaces, such as USB, SCSI, etc., and can be connected with medium such as an external storage, and peripheral devices such as another controller. Furthermore, the expansion connector  60  is connected with a cable LAN adaptor, and can utilize the cable LAN in place of the wireless communication module  50 . The connector for memory card  62  can be connected with an external storage like a memory card. Thus, the input-output processor  42   a , for example, accesses the external storage via the expansion connector  60  and the connector for memory card  62  to store and read the data. 
     Although a detailed description is omitted, as shown in  FIG. 1 , the game apparatus  12  (housing  14 ) is furnished with the power button  20   a , the reset button  20   b , and the eject button  20   c . The power button  20   a  is connected to the system LSI  42 . When the power button  20   a  is turned on, the system LSI  42  sets a mode of a normal energized state (referred to as “normal mode”) in which the respective components of the game apparatus  12  are supplied with power through an AC adapter not shown. On the other hand, when the power button  20   a  is turned off, the system LSI  42  sets a mode in which a part of the components of the game apparatus  12  is supplied with power, and the power consumption is reduced to minimum (hereinafter referred to as “standby mode”). In this embodiment, in a case that the standby mode is set, the system LSI  42  issues an instruction to stop supplying the power to the components except for the input-output processor  42   a , the flash memory  44 , the external main memory  46 , the ROM/RTC  48  and the wireless communication module  50 , and the wireless controller module  52 . Accordingly, the standby mode is a mode in which the CPU  40  never executes an application. 
     Although the system LSI  42  is supplied with power even in the standby mode, supply of clocks to the GPU  42   b , the DSP  42   c  and the VRAM  42   d  are stopped so as not to be driven, realizing reduction in power consumption. 
     Although illustration is omitted, inside the housing  14  of the game apparatus  12 , a fan is provided for excluding heat of the IC, such as the CPU  40 , the system LSI  42 , etc. to outside. In the standby mode, the fan is also stopped. 
     However, in a case that the standby mode is not desired to be utilized, when the power button  20   a  is turned off, by making the standby mode unusable, the power supply to all the circuit components are completely stopped. 
     Furthermore, switching between the normal mode and the standby mode can be performed by turning on and off the power switch  26   h  of the controller  22  by remote control. If the remote control is not performed, setting is made such that the power supply to the wireless controller module  52  is not performed in the standby mode. 
     The reset button  20   b  is also connected with the system LSI  42 . When the reset button  20   b  is pushed, the system LSI  42  restarts the activation program of the game apparatus  12 . The eject button  20   c  is connected to the disk drive  54 . When the eject button  20   c  is pushed, the optical disk  18  is ejected from the disk drive  54 . 
     Each of  FIG. 3(A)  to  FIG. 3(E)  shows one example of an external appearance of the controller  22 .  FIG. 3(A)  shows a front end surface of the controller  22 ,  FIG. 3(B)  shows a top surface of the controller  22 ,  FIG. 3(C)  shows a right side surface of the controller  22 ,  FIG. 3(D)  shows a lower surface of the controller  22 , and  FIG. 3(E)  shows a back end surface of the controller  22 . 
     Referring to  FIG. 3(A)  and  FIG. 3(E) , the controller  22  has a housing  22   a  formed by plastic molding, for example. The housing  22   a  is formed into an approximately rectangular parallelepiped shape and has a size to be held by one hand of a user. The housing  22   a  (controller  22 ) is provided with the input means (a plurality of buttons or switches)  26 . Specifically, as shown in  FIG. 3(B) , on an upper face of the housing  22   a , there are provided a cross key  26   a , a 1 button  26   b , a 2 button  26   c , an A button  26   d , a − button  26   e , a HOME button  26   f , a + button  26   g  and a power switch  26   h . Moreover, as shown in  FIG. 3(C)  and  FIG. 3(D) , an inclined surface is formed on a lower surface of the housing  22   a , and a B-trigger switch  26   i  is formed on the inclined surface. 
     The cross key  26   a  is a four directional push switch, including four directions of front (or upper), back (or lower), right and left operation parts. By operating any one of the operation parts, it is possible to instruct a moving direction of a character or object (player character or player object) that is be operable by a player or instruct the moving direction of a cursor. 
     The 1 button  26   b  and the 2 button  26   c  are respectively push button switches, and are used for a game operation, such as adjusting a viewpoint position and a viewpoint direction on displaying the 3D game image, i.e. a position and an image angle of a virtual camera. Alternatively, the 1 button  26   b  and the 2 button  26   c  can be used for the same operation as that of the A-button  26   d  and the B-trigger switch  26   i  or an auxiliary operation. 
     The A-button switch  26   d  is the push button switch, and is used for causing the player character or the player object to take an action other than that instructed by a directional instruction, specifically arbitrary actions such as hitting (punching), throwing, grasping (acquiring), riding, and jumping, etc. For example, in an action game, it is possible to give an instruction to jump, punch, move a weapon, and so forth. Also, in a roll playing game (RPG) and a simulation RPG, it is possible to give an instruction to acquire an item, select and determine the weapon and command, and so forth. 
     The − button  26   e , the HOME button  26   f , the + button  26   g , and the power supply switch  26   h  are also push button switches. The − button  26   e  is used for selecting a game mode. The HOME button  26   f  is used for displaying a game menu (menu screen). The + button  26   g  is used for starting (re-starting) or pausing the game. The power supply switch  26   h  is used for turning on/off a power supply of the game apparatus  12  by remote control. 
     In this embodiment, note that the power supply switch for turning on/off the controller  22  itself is not provided, and the controller  22  is set at on-state by operating any one of the switches or buttons of the input means  26  of the controller  22 , and when not operated for a certain period of time (30 seconds, for example) or more, the controller  22  is automatically set at off-state. 
     The B-trigger switch  26   i  is also the push button switch, and is mainly used for inputting a trigger such as shooting and designating a position selected by the controller  22 . In a case that the B-trigger switch  26   i  is continued to be pushed, it is possible to make movements and parameters of the player object constant. In a fixed case, the B-trigger switch  26   i  functions in the same way as a normal B-button, and is used for canceling the action determined by the A-button  26   d.    
     As shown in  FIG. 3(E) , an external expansion connector  22   b  is provided on a back end surface of the housing  22   a , and as shown in  FIG. 3(B) , an indicator  22   c  is provided on the top surface and the side of the back end surface of the housing  22   a . The external expansion connector  22   b  is utilized for connecting another expansion controller not shown. The indicator  22   c  is made up of four LEDs, for example, and shows identification information (controller number) of the controller  22  corresponding to the lighting LED by lighting any one of the four LEDs, and shows the remaining amount of power of the controller  22  depending on the number of LEDs to be emitted. 
     In addition, the controller  22  has an imaged information arithmetic section  80  (see  FIG. 4 ), and as shown in  FIG. 3(A) , on the front end surface of the housing  22   a , a light incident opening  22   d  of the imaged information arithmetic section  80  is provided. Furthermore, the controller  22  has a speaker  86  (see  FIG. 4 ), and the speaker  86  is provided inside the housing  22   a  at the position corresponding to a sound release hole  22   e  between the 1 button  26   b  and the HOME button  26   f  on the tope surface of the housing  22   a  as shown in  FIG. 3(B) . 
     Note that, the shape of the controller  22  and the shape, number and setting position of each input means  26  shown in  FIG. 3(A)  to  FIG. 3(E)  are simply examples, and needless to say, even if they are suitably modified, the present invention can be realized. 
       FIG. 4  is a block diagram showing an electric configuration of the controller  22 . Referring to  FIG. 4 , the controller  22  includes a processor  70 , and the processor  70  is connected with the external expansion connector  22   b , the input means  26 , a memory  72 , an acceleration sensor  74 , a wireless communication module  76 , the imaged information arithmetic section  80 , an LED  82  (the indicator  22   c ), an vibrator  84 , a speaker  86 , and a power supply circuit  88  by an internal bus (not shown). Moreover, an antenna  78  is connected to the wireless communication module  76 . 
     The processor  70  is in charge of an overall control of the controller  22 , and transmits (inputs) information (input information) inputted by the input means  26 , the acceleration sensor  74 , and the imaged information arithmetic section  80  as input data, to the game apparatus  12  via the wireless communication module  76  and the antenna  78 . At this time, the processor  70  uses the memory  72  as a working area or a buffer area. 
     An operation signal (operation data) from the aforementioned input means  26  ( 26   a  to  26   i ) is inputted to the processor  70 , and the processor  70  stores the operation data once in the memory  72 . 
     Moreover, the acceleration sensor  74  detects each acceleration of the controller  22  in directions of three axes of vertical direction (y-axial direction), lateral direction (x-axial direction), and forward and rearward directions (z-axial direction). The acceleration sensor  74  is typically an acceleration sensor of an electrostatic capacity type, but the acceleration sensor of other type may also be used. 
     For example, the acceleration sensor  74  detects the accelerations (ax, ay, and az) in each direction of x-axis, y-axis, z-axis for each first predetermined time, and inputs the data of the acceleration (acceleration data) thus detected in the processor  70 . For example, the acceleration sensor  74  detects the acceleration in each direction of the axes in a range from −2.0 g to 2.0 g (g indicates a gravitational acceleration. The same thing can be said hereafter.) The processor  70  detects the acceleration data given from the acceleration sensor  74  for each second predetermined time, and stores it in the memory  72  once. The processor  70  creates input data including at least one of the operation data, acceleration data and marker coordinate data as described later, and transmits the input data thus created to the game apparatus  12  for each third predetermined time (5 msec, for example). 
     In this embodiment, although omitted in  FIG. 3(A)  to  FIG. 3(E) , the acceleration sensor  74  is provided inside the housing  22   a  and in the vicinity on the circuit board where the cross key  26   a  is arranged. 
     The wireless communication module  76  modulates a carrier of a predetermined frequency by the input data, by using a technique of Bluetooth, for example, and emits its weak radio wave signal from the antenna  78 . Namely, the input data is modulated to the weak radio wave signal by the wireless communication module  76  and transmitted from the antenna  78  (controller  22 ). The weak radio wave signal is received by the radio controller module  52  provided to the aforementioned game apparatus  12 . The weak radio wave thus received is subjected to demodulating and decoding processing. This makes it possible for the game apparatus  12  (CPU  40 ) to acquire the input data from the controller  22 . Then, the CPU  40  performs game processing, following the input data and the program (game program). 
     In addition, as described above, the controller  22  is provided with the imaged information arithmetic section  80 . The imaged information arithmetic section  80  is made up of an infrared rays filter  80   a , a lens  80   b , an imager  80   c , and an image processing circuit  80   d . The infrared rays filter  80   a  passes only infrared rays from the light incident from the front of the controller  22 . As described above, the markers  340   m  and  340   n  placed near (around) the display screen of the monitor  34  are infrared LEDs for outputting infrared lights ahead of the monitor  34 . Accordingly, by providing the infrared rays filter  80   a , it is possible to image the image of the markers  340   m  and  340   n  more accurately. The lens  80   b  condenses the infrared rays passing thorough the infrared rays filter  80   a  to emit them to the imager  80   c . The imager  80   c  is a solid imager, such as a CMOS sensor and a CCD, for example, and images the infrared rays condensed by the lens  80   b . Accordingly, the imager  80   c  images only the infrared rays passing through the infrared rays filter  80   a  to generate image data. Hereafter, the image imaged by the imager  80   c  is called an “imaged image”. The image data generated by the imager  80   c  is processed by the image processing circuit  80   d . The image processing circuit  80   d  calculates a position of an object to be imaged (markers  340   m  and  340   n ) within the imaged image, and outputs each coordinate value indicative of the position to the processor  70  as imaged data for each fourth predetermined time. It should be noted that a description of the process in the image processing circuit  80   d  is made later. 
       FIG. 5  is a perspective view showing an appearance of the load controller  36  shown in  FIG. 1 . As shown in  FIG. 5 , the load controller  36  includes a board  36   a  on which a player rides (a player puts his or her foot) and at least four load sensors  36   b  that detect loads applied on the board  36   a . The load sensors  36   b  are accommodated in the board  36   a  (see  FIG. 6  and  FIG. 7 ), and the arrangement of the load sensors  36   b  is shown by dotted line in  FIG. 5 . 
     The board  36   a  is formed in a substantially rectangle, and the board  36   a  has a substantially rectangular shape when viewed from above. For example, a short side of the rectangular is set in the order of 30 cm, and a long side thereof is set in the order of 50 cm. An upper surface of the board  36   a  on which the player rides is formed in flat. Side faces at four corners of the board  36   a  are formed so as to be partially projected in a cylindrical shape. 
     In the board  36   a , the four load sensors  36   b  are arranged at predetermined intervals. In the embodiment, the four load sensors  36   b  are arranged in peripheral portions of the board  36   a , specifically, at the four corners. The interval between the load sensors  36   b  is set an appropriate value such that player&#39;s intention can accurately be detected for the load applied to the board  36   a  in a game manipulation. 
       FIG. 6  shows a sectional view taken along the line VI-VI of the load controller  36  shown in  FIG. 5 , and also shows an enlarged corner portion disposed in the load sensor  36   b . As can be seen from  FIG. 6 , the board  36   a  includes a support plate  360  on which the player rides and legs  362 . The legs  362  are provided at positions where the load sensors  36   b  are arranged. In the embodiment, because the four load sensors  36   b  are arranged at four corners, the four legs  362  are provided at the four corners. The leg  362  is formed in a cylindrical shape with bottom by, e.g., plastic molding. The load sensor  36   b  is placed on a spherical part  362   a  provided in the bottom of the leg  362 . The support plate  360  is supported by the leg  362  while the load sensor  36   b  is interposed. 
     The support plate  360  includes an upper-layer plate  360   a  that constitutes an upper surface and an upper side face, a lower-layer plate  360   b  that constitutes a lower surface and a lower side face, and an intermediate-layer plate  360   c  provided between the upper-layer plate  360   a  and the lower-layer plate  360   b . For example, the upper-layer plate  360   a  and the lower-layer plate  360   b  are formed by plastic molding and integrated with each other by bonding. For example, the intermediate-layer plate  360   c  is formed by pressing one metal plate. The intermediate-layer plate  360   c  is fixed onto the four load sensors  36   b . The upper-layer plate  360   a  has a lattice-shaped rib (not shown) in a lower surface thereof, and the upper-layer plate  360   a  is supported by the intermediate-layer plate  360   c  while the rib is interposed. 
     Accordingly, when the player rides on the board  36   a , the load is transmitted to the support plate  360 , the load sensor  36   b , and the leg  362 . As shown by an arrow in  FIG. 6 , reaction generated from a floor by the input load is transmitted from the legs  362  to the upper-layer plate  360   a  through the spherical part  362   a , the load sensor  36   b , and the intermediate-layer plate  360   c.    
     The load sensor  36   b  is formed by, e.g., a strain gage (strain sensor) type load cell, and the load sensor  36   b  is a load transducer that converts the input load into an electric signal. In the load sensor  36   b , a strain inducing element  370   a  is deformed to generate a strain according to the input load. The strain is converted into a change in electric resistance by a strain sensor  370   b  adhering to the strain inducing element  370   a , and the change in electric resistance is converted into a change in voltage. Accordingly, the load sensor  36   b  outputs a voltage signal indicating the input load from an output terminal. 
     Other types of load sensors such as a folk vibrating type, a string vibrating type, an electrostatic capacity type, a piezoelectric type, a magneto-striction type, and gyroscope type may be used as the load sensor  36   b.    
     Returning to  FIG. 5 , the load controller  36  is further provided with a power button  36   c . When the power button  36   c  is turned on, power is supplied to the respective circuit components (see  FIG. 7 ) of the load controller  36 . It should be noted that the load controller  36  may be turned on in accordance with an instruction from the game apparatus  12 . Furthermore, the power of the load controller  36  is turned off when a state that the player does not ride continues for a given time of period (30 seconds, for example). Alternatively, the power may be turned off when the power button  36   c  is turned on in a state that the load controller  36  is activated. 
       FIG. 7  is a block diagram showing an example of an electric configuration of the load controller  36 . In  FIG. 7 , the signal and communication stream are indicated by solid-line arrows, and electric power supply is indicated by broken-line arrows. 
     The load controller  36  includes a microcomputer  100  that controls an operation of the load controller  36 . The microcomputer  100  includes a CPU, a ROM and a RAM (not shown), and the CPU controls the operation of the load controller  36  according to a program stored in the ROM. 
     The microcomputer  100  is connected with the power button  36   c , the A/D converter  102 , a DC-DC converter  104  and a wireless module  106 . In addition, the wireless module  106  is connected with an antenna  106   a . Furthermore, the four load sensors  36   b  are displayed as a load cell  36   b  in  FIG. 3 . Each of the four load sensors  36   b  is connected to the A/D converter  102  via an amplifier  108 . 
     Furthermore, the load controller  36  is provided with a battery  110  for power supply. In another embodiment, an AC adapter in place of the battery is connected to supply a commercial power supply. In such a case, a power supply circuit has to be provided for converting alternating current into direct current and stepping down and rectifying the direct voltage in place of the DC-DC converter. In this embodiment, the power supply to the microcomputer  100  and the wireless module  106  are directly made from the battery. That is, power is constantly supplied to a part of the component (CPU) inside the microcomputer  100  and the wireless module  106  to thereby detect whether or not the power button  36   c  is turned on, and whether or not a power-on (load detection) command is transmitted from the game apparatus  12 . On the other hand, power from the battery  110  is supplied to the load sensor  36   b , the A/D converter  102  and the amplifier  108  via the DC-DC converter  104 . The DC-DC converter  104  converts the voltage level of the direct current from the battery  110  into a different voltage level, and applies it to the load sensor  36   b , the A/D converter  102  and the amplifier  108 . 
     The electric power may be supplied to the load sensor  36   b , the A/D converter  102 , and the amplifier  108  if needed such that the microcomputer  100  controls the DC-DC converter  104 . That is, when the microcomputer  100  determines that a need to operate the load sensor  36   b  to detect the load arises, the microcomputer  100  may control the DC-DC converter  104  to supply the electric power to each load sensor  36   b , the A/D converter  102 , and each amplifier  108 . 
     Once the electric power is supplied, each load sensor  36   b  outputs a signal indicating the input load. The signal is amplified by each amplifier  108 , and the analog signal is converted into digital data by the A/D converter  102 . Then, the digital data is inputted to the microcomputer  100 . Identification information on each load sensor  36   b  is imparted to the detection value of each load sensor  36   b , allowing for distinction among the detection values of the load sensors  36   b . Thus, the microcomputer  100  can obtain the pieces of data indicating the detection values of the four load sensors  36   b  at the same time. 
     On the other hand, when the microcomputer  100  determines that the need to operate the load sensor  36   b  does not arise, i.e., when the microcomputer  100  determines it is not the time the load is detected, the microcomputer  100  controls the DC-DC converter  104  to stop the supply of the electric power to the load sensor  36   b , the A/D converter  102  and the amplifier  108 . Thus, in the load controller  36 , the load sensor  36   b  is operated to detect the load only when needed, so that the power consumption for detecting the load can be suppressed. 
     Typically, the time the load detection is required shall means the time the game apparatus  12  ( FIG. 1 ) obtains the load data. For example, when the game apparatus  12  requires the load information, the game apparatus  12  transmits a load obtaining command to the load controller  36 . When the microcomputer  100  receives the load obtaining command from the game apparatus  12 , the microcomputer  100  controls the DC-DC converter  104  to supply the electric power to the load sensor  36   b , etc., thereby detecting the load. On the other hand, when the microcomputer  100  does not receive the load obtaining command from the game apparatus  12 , the microcomputer  100  controls the DC-DC converter  104  to stop the electric power supply. Alternatively, the microcomputer  100  determines it is the time the load is detected at regular time intervals, and the microcomputer  100  may control the DC-DC converter  104 . In the case when the microcomputer  100  periodically obtains the load, information on the period may initially be imparted from the game machine  12  to the microcomputer  100  or previously stored in the microcomputer  100 . 
     The data indicating the detection value from the load sensor  36   b  is transmitted as the manipulation data (input data) of the load controller  36  from the microcomputer  100  to the game apparatus  12  ( FIG. 1 ) through the wireless module  106  and the antenna  106   a . For example, in the case where the command is received from the game apparatus  12  to detect the load, the microcomputer  100  transmits the detection value data to the game apparatus  12  when receiving the detection value data of the load sensor  36   b  from the A/D converter  102 . Alternatively, the microcomputer  100  may transmit the detection value data to the game apparatus  12  at regular time intervals. 
     Additionally, the wireless module  106  can communicate by a radio standard (Bluetooth, wireless LAN, etc.) the same as that of the radio controller module  52  of the game apparatus  12 . Accordingly, the CPU  40  of the game apparatus  12  can transmit a load obtaining command to the load controller  36  via the radio controller module  52 , etc. The microcomputer  100  of the load controller  36  can receive a command from the game apparatus  12  via the wireless module  106  and the antenna  106   a , and transmit input data including load detecting values (or load calculating values) of the respective load sensors  36   b  to the game apparatus  12 . 
       FIG. 8  is an illustrative view roughly explaining a state in which the virtual game is played using the controller  22  and load controller  36 . As shown in  FIG. 8 , when playing the virtual game by utilizing the controller  22  and the load controller  36  in the video game system  10 , the player grasps the controller  22  in one hand while riding on the load controller  36 . Exactly, the player grasps the controller  22  with the front-end surface (the side of the incident port  22   d  to which the light imaged by the imaged information arithmetic section  80  is incident) of the controller  22  orientated toward the markers  340   m  and  340   n  while riding on the load controller  36 . However, as can be seen from  FIG. 1 , the markers  340   m  and  340   n  are disposed in parallel with the crosswise direction of the screen of the monitor  34 . In this state of things, the player changes the position on the screen indicated by the controller  22  or the distance between the controller  22  and the marker  340   m  or  340   n  to perform the game manipulation. 
     It should be noted that in  FIG. 8 , the load controller  36  is vertically placed such that the player turns sideways with respect to the screen of the monitor  34 , but depending on the game, the load controller  36  may be horizontally placed such that the player turns front with respect to the screen of the monitor  34 . 
       FIG. 9  is an illustrative view for explaining view angles of the markers  340   m  and  340   n  and controller  22 . As shown in  FIG. 9 , the markers  340   m  and  340   n  each emit the infrared ray in a range of a view angle θ 1 . The imager  80   c  of the imaged information arithmetic section  80  can receive the incident light in a range of a view angle θ 2  around a visual axis direction of the controller  22 . For example, each of the markers  340   m  and  340   n  has the view angle θ 1  of 34° (half-value angle), and the imager  80   c  has the view angle θ 2  of 41°. The player grasps the controller  22  such that the imager  80   c  is set to the position and orientation at which the infrared rays can be received from the two markers  340   m  and  340   n . Specifically, the player grasps the controller  22  such that at least one of the markers  340   m  and  340   n  exists in the view angle θ 2  of the imager  80   c  while the controller  22  exists in the view angle θ 1  of at least one of the markers  340   m  and  340   n . In this state, the controller  22  can detect at least one of the markers  340   m  and  340   n . The player can change the position and orientation of the controller  22  to perform the game manipulation in the range satisfying this state. 
     In the case where the position and orientation of the controller  22  are out of the range, the game manipulation cannot be performed based on the position and orientation of the controller  22 . Hereinafter the range is referred to as “manipulable range”. 
     In the case where the controller  22  is grasped in the manipulable range, the images of the markers  340   m  and  340   n  are taken by the imaged information arithmetic section  80 . That is, the imaged image obtained by the imager  80   c  includes the images (target images) of the markers  340   m  and  340   n  that are of the imaging target.  FIG. 10  is a view showing an example of the imaged image including the target image. Using the image data of the imaged image including the target image, the image processing circuit  80   d  computes the coordinate (marker coordinate) indicating the position in the imaged images of the markers  340   m  and  340   n.    
     Because the target image appears as a high-brightness portion in the image data of the imaged image, the image processing circuit  80   d  detects the high-brightness portion as a candidate of the target image. Then, the image processing circuit  80   d  determines whether or not the high-brightness portion is the target image based on the size of the detected high-brightness portion. Sometimes the imaged image includes not only images  340   m ′ and  340   n ′ corresponding to the two markers  340   m  and  340   n  that are of the target image but also the image except for the target image due to the sunlight from a window or a fluorescent light. The processing of the determination whether or not the high-brightness portion is the target image is performed in order to distinguish the images  340   m ′ and  340   n ′ of the makers  340   m  and  340   n  that are of the target image from other images to exactly detect the target image. Specifically, the determination whether or not the detected high-brightness portion has the size within a predetermined range is made in the determination processing. When the high-brightness portion has the size within the predetermined range, it is determined that the high-brightness portion indicates the target image. On the contrary, when the high-brightness portion does not have the size within the predetermined range, it is determined that the high-brightness portion indicates the image except for the target image. 
     Then, the image processing circuit  80   d  computes the position of the high-brightness portion for the high-brightness portion in which it is determined indicate the target image as a result of the determination processing. Specifically, a position of the center of gravity of the high-brightness portion is computed. Hereinafter, the coordinate of the position of the center of gravity is referred to as marker coordinate. The position of the center of gravity can be computed in more detail compared with resolution of the imager  80   c . At this point, it is assumed that the image taken by the imager  80   c  has the resolution of 126×96 and the position of the center of gravity is computed in a scale of 1024×768. That is, the marker coordinate is expressed by an integer number of (0, 0) to (1024, 768). 
     The position in the imaged image is expressed by a coordinate system (XY-coordinate system) in which an origin is set to an upper left of the imaged image, a downward direction is set to a positive Y-axis direction, and a rightward direction is set to a positive X-axis direction. 
     In the case where the target image is correctly detected, two marker coordinates are computed because the two high-brightness portions are determined as the target image by the determination processing. The image processing circuit  80   d  outputs the pieces of data indicating the two computed marker coordinates. As described above, the outputted pieces of marker coordinate data are added to the input data by the processor  70  and transmitted to the game apparatus  12 . 
     When the game apparatus  12  (CPU  40 ) detects the marker coordinate data from the received input data, the game apparatus  12  can compute the position (indicated coordinate) indicated by the controller  22  on the screen of the monitor  34  and the distances between the controller  22  and the markers  340   m  and  340   n  based on the marker coordinate data. Specifically, the position toward which the controller  22  is orientated, i.e., the indicated position is computed from the position at the midpoint of the two marker coordinates. The distance between the target images in the imaged image is changed according to the distances between the controller  22  and the markers  340   m  and  340   n , and therefore, by computing the distance between the marker coordinates, the game apparatus  12  can compute the current distances between the controller  22  and the markers  340   m  and  340   n.    
     As described above, in a case that the virtual game is played by utilizing the controller  22  and the load controller  36 , game processing can be executed on the basis of a load value detected in the load controller  36 . In this embodiment, when the virtual game is started, prior to starting of the main part, load values of the four load sensors  36   b  in a state the player is in a static state are detected by the load controller  36 , from the detected four load values, a body weight value of the player is calculated (measured), the measured body weight value is set as a reference value (stored in the main memory  42   e  or  46 ), and the game processing is executed on the basis of the set reference value and the load value detected during execution of the virtual game (total value of the load values detected by the four load sensors  36   b  in this embodiment), for example. That is, the body weight value of the player becomes a reference value in a case that the game processing is executed. Here, in the virtual game of this embodiment, in order to eliminate advantage and disadvantage due to the difference in weight of the player, the game processing is executed according to the value (hereinafter referred to as “weight ratio”) obtained by dividing the current load value by the reference value. 
       FIG. 11(A)  and  FIG. 11(B)  each shows an example of a game screen  200  to be displayed on the monitor  34  in a case of playing the virtual game of this embodiment. For example,  FIG. 11(A)  shows the game screen  200  when the player object  202  flies in the sky with its wings flapping (during normal flying). Furthermore,  FIG. 11(B)  shows the game screen  200  when the player object  202  descends with its wings spread widely in an upstanding state almost in order to land in a non player object  204  (during descending). As shown in  FIG. 11(A)  and  FIG. 11(B) , on the game screen  200 , the player object  202  is displayed, and a plurality of non player objects  204  are displayed. The player object (game character)  202  is an object (moving image object) imitating a bird. The non player object  204  is an object as a target to be landed by the player object  202 . 
     In the virtual game, the player object  202  moves (flies) according to an operation by the player, and aims at a final target position (goal) while landing in the plurality of non player objects  204 . For example, when the player object  202  arrives at the goal within a time limit via all of the non player objects  204  to be landed, the game is to be cleared. On the other hand, when the time limit expires before the player object  202  arrives at the goal, when a certain period of time (10 seconds, for example) elapses after the player object  202  falls in the sea surrounding the non player object  204 , or when the player object  202  falls by fixed number of times (three times, for example), the game is over. 
     During the game, the player rides on the load controller  36 , and moves his or her both hands up and down as if a bird flaps (performs a flapping operation). Thereupon, the load value detected by the load controller  36  is varied. Accordingly, the weight ratio WR is also varied. Based on the variation of the weight ratio WR, the movement of the player object  202  is controlled. In this embodiment, the moving amount (moving velocity) of the player object  202  is controlled depending on the strength (change amount of the weight ratio WR) of the swing of the hands (arms) when the player performs a flapping motion, and the moving direction of the player object  202  is controlled in correspondence with a barycentric position of the player on the load controller  36 . 
     More specifically, as shown in  FIG. 12(A) , the player largely spreads both of the hands on the load controller  36 , and performs a motion of largely swinging the both hands up and down with centering on the shoulder (a motion of largely flapping), or as shown in  FIG. 12(B) , the player small spreads both of the hands on the load controller  36 , and performs a motion of swinging the forearms up and down with centering on the elbows (motion of small flapping). 
     Although illustration is omitted, when the player performs a motion of largely flapping (large-flapping motion), the player object  202  is also displayed by the animation of a large-flapping motion on the monitor  34 , and when the player performs a motion of small flapping (small-flapping motion), the player object  202  is also displayed by the animation of a small-flapping motion on the monitor  34 . Although illustration is omitted, the animation of the large-flapping motion is set to make the movable range (movable range in the up and down direction) of the wings wider (larger) in comparison with the animation of the small-flapping motion. 
     Here, judgment method as to the large-flapping motion and the small-flapping motion which are to be performed by the player is explained.  FIG. 13  shows one example of a graph of a time variation of the weight ratio WR when the player performs a large-flapping motion shown in  FIG. 12(A) . Furthermore,  FIG. 14  shows one example of a graph of a variation of the weight ratio WR when the player performs a small-flapping motion shown in  FIG. 12(B) . In  FIG. 13  and  FIG. 14  (this is true for  FIG. 15 ), the time variation of the weight ratio WR is indicated by a solid line waveform. Here, by regarding when the weight ratio WR is 1.0, that is, when the body weight value (reference value) and the current load value match with each other as a reference, the upper side of the graph is a side where the load of the player detected by the load controller  36  is added, and on the lower side of the graph is a side where the load of the player detected by the load controller  36  is reduced. 
     When each of the time variations of the weight ratio WR as shown in  FIG. 13  and  FIG. 14  is subjected to a discrete Fourier transform, a power spectrum (the amplitude A with respect to the index number n of the frequency) is obtained. In  FIG. 13  and  FIG. 14  (this holds true for  FIG. 15 ), the power spectrum is indicated by a dot. The reason why the discrete Fourier transforming processing is executed is for correctly confirming a flapping motion of the player (specifically, large-flapping motion). That is, this is because that it is difficult to distinguish between the small-flapping motion and the large-flapping motion from the waveform of the time variation of the weight ratio WR. 
     Here, when in the discrete Fourier transform, and the number of data of the waveform shall be x, a time interval shall be dt (seconds), the frequencies f are 1/(x·dt) intervals. In this embodiment, x=30, dt= 1/60 (game frame), and thus the frequencies f (Hz) is 2 intervals. Accordingly, the value obtained by doubling the index number n becomes the frequency f (Hz). Here, the game frame is a screen updating rate. 
     As understood from  FIG. 13 , in a case of a large-flapping motion, when the index number n=1 of the frequency, the amplitude A becomes the maximum value. Furthermore, as understood from  FIG. 14 , in a case of a small-flapping motion, when the index number n=2 of the frequency, the amplitude A becomes the maximum value. Accordingly, the time variation of the weight ratio WR is subjected to the discrete Fourier transform, and by searching the index number n of the frequency when the amplitude A is the maximum, it is considered that whether a large-flapping motion or a small-flapping motion is performed can be judged. Although illustration is omitted, depending on the result of the experiments, in a case of that the player performs a large-flapping motion as well, when the index number n=2 of the frequency, the amplitude A sometimes becomes the maximum value due to the influence of a noise. Thus, in this embodiment, whether the large-flapping motion or the small-flapping motion is judged according to Equation 1. In a case that the index number n, or the index number n of the frequency when the amplitude A becomes the maximum value and the amplitude A satisfy the Equation 1, the small-flapping motion is judged, and when they do not satisfy the Equation 1, the large-flapping motion is judged. Here, the maximum value of the noise (spectrum noise) when the large-flapping motion is performed shall be Pn (0.0001).
 
 n≧ 3  [Equation 1]
 
     or 
     n=2 and the A is the maximum, and n=3 and A≧Pn 
     However, when the Equation 1 is not satisfied, if as to all the index numbers n=1-15 of the frequency, each of all the amplitude A is less than Pn, it is considered that there is no cyclic motion, and thus, it is determined that the player does not perform a flapping motion. 
     When the presence or absence of a flapping motion of the player and the kind (large-flapping motion or small-flapping motion) of the flapping motion are judged, an animation is selected depending on the kind of the flapping motion, and selected animation is reproduced. Accordingly, as described above, according to the flapping motion of the player, an animation showing the flapping motion of the player object  202  is displayed on the monitor  34 . 
     Here, if the player does not perform a flapping motion, and the player object  202  descends in the three-dimensional virtual space, an animation showing that the player object  202  is descending (animation during descending) is reproduced. 
     As described above, in this embodiment, the player riding on the load controller  36  performs a flapping motion, so that the load value detected by the load controller  36  is varied, and the weight ratio WR is also varied. Accordingly, for example, in a case that the player riding on the load controller  36  performs bending and stretching exercises as well, the load value detected by the load controller  36  is cyclically varied similar to a case that the player performs a flapping motion. One example of the graph of a time variation of the weight ratio WR is shown in  FIG. 15 . As can be understood by comparison with  FIG. 13  or  FIG. 15 , in a case that the bending and stretching exercises is performed, the variation of the weight ratio WR is made larger in comparison with a case that a flapping motion is performed. 
     Although shown in detail later, in this embodiment, a driving force depending on the magnitude of the weight ratio WR (negative value) is given to the player object  202 , and by the driving force, the player object  202  moves within the three-dimensional virtual space. Thus, in a case that the player performs the bending and stretching exercises, a driving force larger than a case that the player performs a flapping motion can be applied to the player object  202  to thereby allow the player object  202  to be moved largely. However, such the bending and stretching exercises is not an operation method that the developer, et al. intends to. 
     Accordingly, in this embodiment, in a case that there is a weight ratio WR above a fixed threshold value (1.3, for example) in the immediately-preceding flapping motion (flapping section) of the player, it is determined that an unintended motion, such as the bending and stretching exercises is performed, the score of the virtual game is decreased, or the player object  202  is made to be hard to advance. 
     In this embodiment, a section from the start of the last-but-one-arm-lowering motion to the start of the previous (immediately-preceding)-arm-lowering motion is recognized as an immediately-preceding-flapping motion (flapping section). Here, in  FIG. 13 - FIG. 15 , the start point of an arm-lowering motion is represented by alternate long and short dash lines. The arm-lowering motion means a motion of lowering the both hands or the arms down in the flapping motion. The determination method of the start of the arm-lowering motion is explained in detail later. However, as described above, since the time variation of the weight ratio WR shown in  FIG. 15  is obtained is when the player performs the bending and stretching exercises, in the determination processing described later, not the start of an arm-lowering motion but the start of a leg-bending motion is determined. 
     As described above, during the game, a driving force Acc based on the weight ratio WR is applied to the player object  202 . In this embodiment, the driving force Acc is calculated according to Equation 2. Here, the weight ratio WR is less than a predetermined threshold value (0.985 in this embodiment). The reason why the driving force Acc is applied when the weight ratio WR is smaller than 1.0 is to allow the player object  202  to obtain a driving force when the player performs an arm-lowering motion just as a bird obtains a driving force when it moves the wings down. Accordingly, it can be said that in the flapping motion to be performed by the player, raising the both hands or the both arms upward (arm-raising motion) is a preparation motion of an arm-lowering motion to obtain a driving force. Furthermore, the reason whey the weight ratio WR is less than the predetermined threshold value is to eliminate the influence of the noise.
 
driving force Acc=1.0−weight ratio WR  [Equation 2]
 
     Here, as understood from the Equation 2, the smaller the weight ratio WR is, the larger the driving force Acc is. That is, in a case of a large variation of the load value, the driving force Acc becomes large. In addition, the driving force Acc is given when the weight ratio WR is less than the predetermined threshold value and the driving force Acc is reflected on the movement of the player object  202  every one game frame, so that the longer the time during which the weight ratio WR is less than the predetermined threshold value is, that is, the longer the one cycle of the flapping motion is, such as a large-flapping motion, the more the number of obtainments of the driving force Acc is. As a result, a large driving force Acc is applied to the player object  202 , and thus, a moving distance or a moving velocity of the player object  202  is increased (see Equation 3 and Equation 4). 
     The driving force Acc calculated in the Equation 2 is a scalar quantity, but in the three-dimensional virtual space, a unit vector (Y vector) AccDir extending from the head directly above in a state that the player object  202  stands still is multiplied by the scalar quantity which is transformed into a value (AccSim) utilized in an integration simulation. Here, the unit vector AccDir is decided by rotating the player object  202  about the x-axis and the y-axis of the local coordinates in correspondence with the barycentric position of the player as described later. 
     In the integration simulation, the position (three-dimensional position) Pos of the player object  202  after movement is calculated according to Equation 3 and Equation 4 on the basis of the driving force Acc. Here, the player object  202  is moved to a direction the head turns to, that is, the direction of the unit vector AccDir in the current game frame (current frame). In addition, in the Equation 3 and Equation 4, a velocity of the player object  202  in a next game frame (next frame) shall be Vel_new, a velocity before movement, that is, the velocity in the current frame shall be Vel_old, a gravitational acceleration vector in the three-dimensional virtual space shall be Gravity, a three-dimensional position in the current frame shall be Pos_old, and a three-dimensional position in the next frame shall be Pos_new. Furthermore, in the Equation 3, an acceleration vector (AccBoard×FallTransDir) in a case that the player object  202  moves in a forward and backward direction during descending is reflected on the velocity in the next frame Vel_new. Here, the AccBoard is a translational acceleration (acceleration in the horizontal direction), and the FallTransDir is a direction vector in a translational direction (horizontal direction) (vector of the front direction or back direction of the player object  202 ).
 
Vel_new={Vel_old+(AccSim×AccDir)+(AccBoard×FallTransDir)+Gravity}×0.994  [Equation 3]
 
Pos_new=Pos_old+Vel_new  [Equation 4]
 
     Here, in this embodiment, the gravitational acceleration vector Gravity shall be (0, −0.014, 0). In this embodiment, the distance 1 m in the real world shall be a distance  10  within the three-dimensional virtual space, but when the gravitational acceleration. Gravity is set in correspondence with the ratio, it is difficult to obtain enough driving force to fly the player object  202  by the flapping motion of the player, and therefore, the gravitational acceleration Gravity is set to a relatively smaller value empirically obtained by experiments, etc. In addition, 0.994 is air resistance. This is not required to be a constant, and may be variably set in correspondence to the progress of the virtual game. 
     As understood from the Equation 3, the velocity in the next frame Vel_new can be obtained by adding the acceleration vector ((AccSim×AccDir) or (AccBoard×FallTransDir)) and the gravitational acceleration vector Gravity to the velocity in the current frame Vel_old and then multiplying the added value by the air resistance. Furthermore, as understood from the Equation 4, the coordinate in the next frame Pos_new is obtained by adding the velocity in the next frame Vel_new to the coordinate in the current frame Pos_old. This is obtained as a result of integrating the driving force AccSim to be used in the simulation (twice integration). 
     Additionally, in a case that no flapping operation is made by the player, the weight ratio WR is 1 or approximately 1, and the driving force AccSim (acceleration vector (AccSim×AccDir)) to be used for the simulation becomes 0, and the Equation 3 is shown as in Equation 5.
 
Vel_new={Vel_old+(AccBoard×FallTransDir)+Gravity}×0.994  [Equation 5]
 
     Accordingly, a Y component of the velocity in the next frame Vel_new is reduced by 0.014 for each game frame. Thus, free fall in the three-dimensional virtual space is represented. That is, in the Equation 3, a translational movement of the object when a driving force occurs in the gravitational filed within the three-dimensional virtual space is described. 
     Furthermore, in a case that a flapping operation by the player occurs, and the player object  202  does not descend, the acceleration vector (AccBoard×FallTransDir) of the player object  202  in the forward and backward direction during descending becomes 0 according to the Equation 3. 
     In this manner, the three-dimensional position Pos_new after movement in the three-dimensional virtual space of the player object  202  is calculated, and the player object  202  is placed in the three-dimensional virtual space according to the determinant A shown in Equation 6. Here, each element of the determinant A shown in  FIG. 6  means as follows. An element (Xx, Xy, Xz) is a direction to which an x-axis of the local coordinate of the player object  202  is applied, an element (Yx, Yy, Yz) is a direction to which a y-axis of the local coordinate of the player object  202  is applied, an element (Zx, Zy, Zz) is a direction to which a z-axis of the local coordinates of the player object  202  is applied, and an element (Px, Py, Pz) is world coordinate (three-dimensional coordinate) where the center (gravity) of the local coordinate of the player object  202  is placed. 
     
       
         
           
             
               
                 
                   A 
                   = 
                   
                     [ 
                     
                       
                         
                           Xx 
                         
                         
                           Yx 
                         
                         
                           Zx 
                         
                         
                           Px 
                         
                       
                       
                         
                           Xy 
                         
                         
                           Yy 
                         
                         
                           Zy 
                         
                         
                           Py 
                         
                       
                       
                         
                           Xz 
                         
                         
                           Yz 
                         
                         
                           Zz 
                         
                         
                           Pz 
                         
                       
                     
                     ] 
                   
                 
               
               
                 
                   [ 
                   
                     Equation 
                     ⁢ 
                     
                         
                     
                     ⁢ 
                     6 
                   
                   ] 
                 
               
             
           
         
       
     
     Furthermore, during the game, depending on the barycentric position of the load of the player on the load controller  36 , the direction of travel (moving direction) of the player object  202  is decided (controlled). In  FIG. 16(A) , the center of the top surface (surface of the upper-layer plate  360   a  of the support plate  360 ) of the load controller  36 , that is, the center of the range of detection of the barycentric position is set to the origin point O (0, 0), and the orientation (moving direction) of the head of the player object  202  is decided by a shift length of the barycentric position from the origin point O in a horizontal plane. Here, a horizontal direction of the support plate  360  of the load controller  36  is an x-axis direction of the range of detection, and a vertical direction thereof is a y-axis direction of the range of detection. It should be noted that the direction of the face when the player correctly rides on the load controller  36  (front direction) is an upper direction of the paper in  FIG. 16(A) . Furthermore, as shown in  FIG. 16(A) , a right direction of the range of detection is a plus direction of the x-axis, and an upper direction of the range of detection is a plus direction of the y-axis. 
     Here, in a situation in  FIG. 16(A) , the load detection value at the upper left of the load sensor  36   b  is R 1 , the load detection value at the lower left of the load sensor  36   b  is R 2 , the load detection value at the upper right of the load sensor  36   b  is R 3 , and the load detection value at the lower right of the load sensor  36   b  is R 4 , an x coordinate (XG) of the barycenter in the coordinate system of the range of detection is calculated on the basis of the difference between the right load value and the left load value, and a y coordinate (YG) of the barycenter is calculated on the basis of the difference between the upper load value and the lower load value. The x coordinate (XG) of the barycenter is calculated according to Equation 7, and the y coordinate of the barycenter (YG) is calculated according to Equation 8.
 
 XG =(( R 3 +R 4)−( R 1 +R 2))× k 1  [Equation 7]
 
 YG =(( R 1 +R 3)−( R 2 +R 4))× k 2  [Equation 8]
 
     Here, k1, k2 are constants. Noted that −1≦XG≦1, −1≦YG≦1. 
     Additionally, in this embodiment, the center of the range of detection of the load controller  36  is set to be the origin point O, but a standing position is different from player to player, and therefore, the barycentric position when the player rides on the load controller  36  and measure the body weight value may be set to the origin point O. In this embodiment, in a case that the player object  202  flies, a controlling method of the moving direction is differentiated between when the player object  202  descends and does not descend. Each case is explained in detail hereafter. 
     In a case that the player object  202  does not descend, the player object  202  rotates in the right and left direction according to the x coordinate of the barycentric position of the load detected by the load controller  36  and rotates in the forward and backward direction according to the y coordinate of the barycentric position. 
     In a case that the barycentric position is included in an area (I) or an area (III) within the range of detection, and the x coordinate of the barycentric position is negative, the player object  202  is rotated counterclockwise (to the left direction) about the y-axis of the local coordinate. Furthermore, in a case that the barycentric position is included in an area (II) or an area (IV) within the range of detection, and the x coordinate of the barycentric position is positive, the player object  202  is rotated clockwise (to the right direction) about the y-axis of the local coordinate. 
     More specifically, as shown in  FIG. 16(B) , in a case that the player object  202  is seen from above, a counterclockwise rotation amount of the player object  202  about the y-axis of the local coordinates is decided according to the negative value of the x-coordinate of the barycentric position, and a clockwise rotation amount of the player object  202  about the y-axis of the local coordinate is decided according to the positive value of the x-coordinate of the barycentric position. The rotation amount is proportional to the magnitude of the x-coordinate of the barycentric position. Furthermore, in a case that the x-coordinate of the barycentric position is a positive value, the player object  202  continues to rotate clockwise about the y-axis of the local coordinate. 
     Here, in this embodiment, in the local coordinate system, when the player object  202  is a standstill state, a lateral (horizontal) direction is an x-axis direction, and a longitudinal (vertical) direction is a y-axis direction, and a backward and forward (depth) direction is a z-axis direction. Furthermore, each axis passes through the center or the barycenter of the player object  202 . In addition, when the player object  202  is in a standstill state, the left hand (left wing) direction is a plus direction of the x-axis of the local coordinate, the upper direction is a plus direction of the y-axis of the local coordinate, and the forward direction (direction of the belly) is a plus direction of the z-axis of the local coordinate. 
     Furthermore, in a case that the barycentric position is included in the area (I) or the area (II) within the range of detection, and the y-coordinate of the barycentric position is positive, the player object  202  is rotated about the x-axis of the local coordinate such that the head is inclined forward (front direction) as shown in  FIG. 17 . The inclination amount (rotation amount) to the front direction is proportion to the magnitude of the y-coordinate of the barycentric position, but the maximum inclination amount is 55 degrees from the standstill state of the player object  202 . 
     Although illustration is omitted, in a case that the barycentric position is included in the area (III) or the area (IV) within the range of detection, and the y-coordinate of the barycentric position is negative, the player object  202  is rotated about the x-axis of the local coordinate backward. It should be noted that the maximum inclination amount of the player object  202  backward is set to 35 degrees. This is because of eliminating an undesired state in which the player object  202  flies with the belly upward. 
     On the other hand, in a case that the player object  202  descends, the player object  202  is rotated to the horizontal direction according to the x-coordinate of the barycentric position of the load detected by the load controller  36 , and translated in the forward and backward direction according to the y-coordinate of the barycentric position. 
     In a case that the player object  202  descends as well, the player object  202  is rotated about the y-axis of the local coordinate according to the x-coordinate of the barycentric position. This is the same explanation as that made with reference to  FIG. 16(B) , and therefore, a redundant explanation is omitted. 
     Furthermore, in a case that the player object  202  descends, the player object  202  is moved (translated) in the forward and backward direction according to the y-coordinate of the barycentric position as shown in  FIG. 18 . That is, in such a case, the head of the player object  202  is not inclined. Furthermore, the moving amount (displacement amount) when the player object  202  is translated is decided by the magnitude of the y-coordinate of the barycentric position. The reason why the player object  202  is thus translated according to the y-coordinate of the barycentric position when descending is to make it easy to land the player object  202  in the non player object  204 . In a case that the y-coordinate of the barycentric position is positive, the player object  202  is moved (translated) in the front direction. At this time, when the y-coordinate becomes large, the moving amount is also increased. On the other hand, in a case that the y-coordinate of the barycentric position is negative, the player object  202  translates in a direction opposite to the front direction (rear direction). At this time, when the y-coordinate becomes small, that is, becomes large in the negative direction, the moving amount is increased. It should be noted that the maximum value of the moving amount by the player object  202  for one game frame is set in advance. 
     Furthermore, from the time variation of the weight ratio WR shown in  FIG. 13 - FIG. 15 , a start of a motion of raising the arms upward by the player (arm-raising motion) is determined (arm-raising determination) while a start of a motion of lowering the arms downward (arm-lowering motion) is determined (arm-lowering determination). This is because of synchronizing the flapping motion of the player and the animation of the flapping motion of the player object  202 . 
     Explanation is made on an arm-lowering determination method, an arm-raising determination method, and a synchronization between the flapping motion of the player and the animation of the flapping motion of the player object  202 , in order. 
     In this embodiment, when the weight ratio WR in the current frame is smaller than weight ratio WR in the immediately-preceding game frame (previous frame), and the value of the weight ratio WR in the current frame becomes less than a certain value (0.985), it is determined that an arm-lowering motion is started. Alternatively, in this embodiment, when the value of the weight ratio WR is equal to or more than a certain value (0.98), and the weight ratio WR is decreased and then increased, it is determined that an arm-raising motion is started. More specifically, in a case that the weight ratio WR in the previous frame is smaller than the weight ratio WR in a last-but-one game frame (last but one frame), and the weight ratio WR in the current frame is equal to or more than the weight ratio WR in the previous frame by a certain value (0.001) or more, it is detected that the weight ratio WR is decreased and then increased, and moreover, in a case that the weight ratio WR in the previous frame is equal to or more than the certain value (0.98), it is determined that an arm-raising motion is started. Thus, when on the side of the area where the weight ratio WR is lager than the reference value (1.0) (upper side), on the basis of the variation of the weight ratio WR during a fixed section (3 game frames), it is detected that the weight ratio WR is locally (temporarily) decreased (decrease of the load value) and increased, it is determined that a arm-raising motion is started. These are determination methods empirically obtained on the basis of the time variation of the weight ratio WR as shown in  FIG. 13  and  FIG. 14 . 
     Here, the decrease of the weight ratio WR means that the weight ratio WR in the current frame is smaller than the weight ratio WR in the previous frame, and the increase of the weight ratio WR means that the weight ratio WR in the current frame is larger than the weight ratio WR in the previous frame. Furthermore, the reason why in a case of determining the start of an arm-raising motion, the weight ratio WR is equal to or more than the certain value is made as a condition is to prevent the start of the arm-raising motion in the vicinity of the minimum value, such as around 0.9, from being determined as shown in  FIG. 13 . That is, in this embodiment, in a case that the player performs a large-flapping motion, a motion of raising the both hands (the both arms) as high as or higher than the shoulder is determined to be an “arm-raising motion”. This is the “arm-raising motion” of the player intended by a developer, et al. 
     In  FIG. 13 - FIG. 15  described above, the start of the arm-lowering motion is shown by the alternate long and short dash line. Furthermore, in  FIG. 13 , the start of the arm-raising motion is shown by alternate long and two short dashes line. 
     Next, the synchronization between the flapping motion of the player and the animation of the flapping motion of the player object  202  is explained. First, the animation of the player object  202  is constructed of 60 frames irrespective of the kind (large or small) of flapping motion. As described above, the difference depending on the flapping kinds is only the size of a movable range of the wing. The synchronization between the flapping motion of the player and the animation of the flapping motion of the player object  202  is explained later as to the large-flapping motion, but this holds true for the small-flapping motion. 
     In  FIG. 19 , the characteristic animation frames (0 (60), 7, 15, 22, 30, 37, 45, 52, here) out of 60 frames (animation frame) as to the large-flapping animation are extracted. The animation frame starts from 0 to 59, and returns to 0 at the animation frame  60 . Here, in  FIG. 19 , for simplicity, only the head, the body, and the wings of the player object  202  are shown. Furthermore, in  FIG. 19 , the front direction of the player object  202  is a vertical direction with respect to the paper. In addition, in  FIG. 19 , on the upper line, the animation frame from 0 to 30 is represented, and on the lower line, the animation frame from 30 to 60 (0) is shown. 
     As shown in  FIG. 19 , when the animation frame is 0, the player object  202  spreads the wings in the horizontal direction, for example, and the angle formed by the wings with respect to the horizontal plane of the three-dimensional virtual space is 0 degrees. In this embodiment, when the animation frame is reproduced, the player object  202  raises the wing from the spread state in the horizontal direction, and reaches the wings at the highest position when the animation frame is the 15th frame, and then lowers the wings. Then, the wings reach the lowest position when the animation frame is 45th frame, and then is raised to return to the initial state at the 60th frame (0th frame). 
     Accordingly, from the 15th frame until just before the 45th frame (15→22→30→37→45) correspond to the animation frame as to an arm-lowering motion of the player object  202 , and from the 45th frame until just before the 15th frame (45→52→60(0)→7→15) correspond to the animation frame as to an arm-raising motion of the player object  202 . 
     Furthermore, as shown in  FIG. 19 , an arm-lowering-acceleration-probable section (15-30th frames) is set in correspondence with an arm-lowering motion of the player object  202  or the animation frame (15-45th frames), and an arm-raising-acceleration-probable section (30-60th frames) is set in correspondence with an arm-raising motion of the player object  202  or the animation frame (45-15th frames). That is, the arm-lowering-acceleration-probable section is set from the start to the middle of the animation frame as the arm-lowering motion. Alternatively, the arm-raising-acceleration-probable section is set from the middle of the animation frame as to the arm-lowering motion to the middle of the animation frame as to the arm-raising motion. Accordingly, the arm-raising-acceleration-probable section includes the animation frame (30-45th frames) as to a part of the arm-lowering motion (preliminary motion for the arm-raising motion). As shown in  FIG. 19 , the reasons why the arm-lowering-acceleration-probable section and the arm-raising-acceleration-probable section are set is described later, and are omitted here. 
     It should be noted that the animation frame is 60 pieces (60 frames), the number of frames (fame number) may be designated by arithmetic point. For example, the angle (angle formed by the horizontal plane) of the arms of the player object  202  is 0 degrees of the 0th frame in the animation frame, and the angle of the arms of the player object  202  in the first frame in the animation frame is 10 degrees, and when 0.5 is designated as a frame number, it is possible to obtain the player object  202  with 5 degrees of the angle of the arms. Accordingly, logically, the pose of the player object  202  can take limitless kinds. 
     In this embodiment, as a method of taking a synchronization between the flapping motion of the player and the animation frame of the player object  202 , there are an advancing method A of the animation frame when it is determined that the arm-lowering motion is started or after it is determined that the arm-lowering motion is started and an advancing method B of the animation frame when it is determined that an arm-raising motion is started or after it is determined that an arm-raising motion is started. Here, in a case that the player performs a small-flapping motion, the arm-raising motion is not determined, and therefore, the synchronization is taken only by the advancing method A of the animation frame. That is, in a case that the player performs a large-flapping motion intended by the developer, et al. as explained with reference to  FIG. 12(A) , an arm-lowering motion and the arm-raising motion are determined, and therefore, by utilizing the advancing method A of the animation frame and the advancing method. B of the animation fame, a synchronization is taken between the flapping motion of the player and the animation frame of the player object  202 . 
     First, the advancing method A of the animation frame is explained. As described above, when it is determined that an arm-lowering motion is started, an arm-lowering-acceleration flag  404   p  (see  FIG. 21 ) described later is turned on. In a case that the arm-lowering-acceleration flag  404   p  is turned on, it is determined whether or not the current animation frame is within the arm-lowering-acceleration-probable section (fame number: equal to or more than 15 and less than 30) shown in  FIG. 19 . 
     Here, as described later, the arm-lowering-acceleration flag  404   p  is turned off when an updating (advancing) velocity of the animation frame in the arm-lowering-acceleration-probable section is accelerated. 
     When it is determined that an arm-lowering motion is started, if the current animation frame is within the arm-lowering-acceleration-probable section, an arm-lowering acceleration is generated. That is, a value larger than 0 is set to the acceleration FrameAcc of the animation frame, and the updating velocity is made faster than the game frame ( 1/60 (seconds)). In this embodiment, the frame acceleration FrameAcc of the animation frame is calculated according to the Equation 9. Here, the AnimFrameMax is the maximum number of frames (60, in this embodiment). Furthermore, the CycleSwing is a time required for one flapping motion (flapping section), that is, a time interval during which an arm-lowering determination is made, and is represented by the number of game frames. This holds true hereafter. Accordingly, as a cycle during which a flapping motion is performed is short, the frame acceleration FrameAcc of the animation frame is set to a larger value, and the updating velocity of the animation frame is made high.
 
FrameAcc=AnimFrameMax/CycleSwing  [Equation 9]
 
     Thus, when the frame acceleration FrameAcc is generated at a time when or directly after the arm-lowering motion by the player is made, the advance of the animation frame is made faster at this moment, and the animation showing that the player object  202  moves the wings downward is reproduced at the same time. Thus, it seems that the flapping motion of the player and flapping motion of the player object  202  take synchronization (are linked). Thereafter, the animation frame advances through inertia until a next arm-lowering motion or arm-raising motion is determined. That is, if there is no acceleration (FrameAcc=0), the frame velocity of the animation frame is reduced due to the air resistance, and becomes 0 to thereby stop reproducing the animation soon. 
     More specifically, the number of frames of the animation frame when the game screen is displayed (updated) is decided according to Equation 10 and Equation 11. Here, the updating (advancing) velocity of the animation frame (frame velocity) is represented by FrameVel, the acceleration of the animation frame (frame acceleration) is represented by FrameAcc, and the number of frames (number) of the animation frame is represented by Frame. Furthermore, “old” is applied to the value of the current frame (at this time), and “new” is applied to the next frame (at the next time). Accordingly, in the Equation 10, the next frame velocity taking the air resistance into account is calculated, and in the Equation 11, the next frame number is calculated.
 
FrameVel_new=(FrameVel_old+FrameAcc)×0.99  [Equation 10]
 
Frame_new=Frame_old+FrameVel_new  [Equation 11]
 
     Here, 0.99 is air resistance. Accordingly, the air resistance need not to be a constant, and may be variably set in correspondence with the progress of the game. 
     On the other hand, when it is determined that the arm-lowering motion is started, if the current animation frame is not within the arm-lowering-acceleration-probable section, the animation frame is advanced according to the frame velocity (Noted that frame acceleration AnimeVcc=0) calculated in Equation 12 to the arm-lowering-acceleration-probable section.
 
FrameVel_old=AnimFrameMax×1.7/CycleSwing  [Equation 12]
 
     Then, when the animation frame advance to the arm-lowering-acceleration-probable section, the frame acceleration FrameAcc is generated as described above, the synchronization between the flapping motion of the player and the flapping motion of the player object  202  is taken 
     Here, as understood by comparing the Equation 9 and the Equation 12, the frame velocity obtained in the Equation 12 is 1.7 times as fast as the acceleration FrameAcc obtained in the Equation 9. For example, in a case that the animation frame is 7th frame, when it is determined that an arm-lowering motion is started, the animation frame advances to reach the 15th frame at the 1.7-fold frame velocity obtained in the Equation 12, and then advances to reach the 30th frame at the frame velocity calculated in the Equation 10. Here, in this case, the arm-lowering motion is performed outside the arm-lowering-acceleration-probable section, and therefore the acceleration FrameAcc is 0 from the 15th frame to the 30th frame. Accordingly, the frame velocity of the animation frame is reduced (attenuated) from the 15th frame to the 30th frame due to the air resistance (0.99, here). That is, the frame velocity from the 7th frame to the 15th frame is faster than the frame velocity from the 15th frame to the 30th frame (arm-lowering-acceleration-probable section), and is constant velocity. 
     Accordingly, in this case, the updating velocity of the animation frame is not temporarily accelerated and then decelerated from the 15th frame to the 30th frame, and therefore, it is impossible to make the player object  202  perform a motion as if a real bird (relatively large bird) is flapping. 
     However, in a case that the determination as to the start of the arm-lowering motion is out of the arm-lowering-acceleration-probable section as described above, the animation frame advances to the 15th frame at the 1.7-fold frame velocity, decelerates from the 15th frame to the 30th frame, and then enter a next arm-lowering determination, as a cycle (hereinafter, referred to as “cycle A”), so that one flapping motion by the player ensures one flapping motion by the player object  202  (animation frame advances from the 0-th frame to the 59th frame). Furthermore, in such a case, in the arm-lowering-acceleration-probable section, the frame velocity is not accelerated, but the animation frame is updated at the 1.7-fold frame velocity in response to the player starting an arm-lowering motion. That is, in response to a motion by the player, the motion of the player object  202  is controlled, so that the player does not feel uncomfortably. 
     In addition, the frame velocity evaluated according to the Equation 12 is inverse proportion to the flapping section (flapping cycle) CycleSwing being a time interval for determining the start of an arm-lowering motion, so that if a slow flapping motion is performed, the cycle A slowly proceeds, and if a quickly flapping motion is performed, the cycle A quickly proceeds. 
     Thus, even if the advance of the animation frame is controlled by merely determining the start of the arm-lowering motion, it is possible to take a synchronization between the flapping motion of the player and animation. 
     As described above, when it is determined that an arm-lowering motion is started, in a case that the current animation frame is within the arm-lowering-acceleration-probable section, the frame acceleration FrameAcc is generated, and then, the animation frame is updated through inertia according to the Equation 10 and Equation 11. However, this results in the animation frame being late for a flapping motion including a next arm-lowering motion by the player. 
     In order to cancel the delay, in this embodiment, in a case it is determined that an arm-raising motion is started in accordance with the player performing a large-flapping motion, the advancement of the animation frame is controlled not only by the advancing method A of the animation frame but also the advancing method B of the animation frame. 
     That is, the synchronization between a flapping motion of the player and the animation frame is taken to a certain degree by the advancing method A of the animation frame, and the synchronization between the flapping motion of the player and the animation frame is taken more precisely by the advancing method B of the animation frame. 
     As described above, the frame velocity obtained in the Equation 12 is 1.7 times as fast as the acceleration FrameAcc obtained in the Equation 9. This is the magnification set for making the frame velocity higher than the acceleration FrameAcc obtained by the flapping motion (arm-lowering motion) of the player, and is a numerical value empirically obtained by experiment, etc. 
     Next, the advancing method B of the animation frame is explained. As described above, when it is determined that an arm-raising motion is started, an arm-raising-acceleration flag  404   n  (see  FIG. 21 ) described later is turned on. In a case that the arm-raising-acceleration flag  404   n  is turned on, it is determined whether or not the current animation frame is within the arm-raising-acceleration-probable section (fame number: equal to or more than 30 and less than 60) shown in  FIG. 19 . 
     As described later, when the updating velocity of the animation frame is accelerated in the arm-raising-acceleration-probable section, the arm-raising-acceleration flag  404   n  is turned off. 
     When it is determined that the arm-raising motion is started, in a case that the current animation frame is within the arm-raising-acceleration-probable section, an arm-raising acceleration is generated. That is, a value larger than 0 (2, in this embodiment) is set to the frame acceleration FrameAcc, and the updating velocity is set to be faster than the game frame ( 1/60 (seconds)). Here, if the current frame velocity FrameVel_old is equal to or more than 2, the frame acceleration FrameAcc is set to 0. That is, when or directly after an arm-raising motion by the player is performed, a frame acceleration FrameAcc is generated, and the advancement of the animation frame is made the fastest at this moment, and an animation showing that the player object  202  moves the wings upward at the same time. Thus, it seems that the flapping motion of the player and the flapping motion of the player object  202  are synchronized with each other. Accordingly, in a case that it does not seem that the flapping motion of the player and the animation frame are synchronized, the player can understand that his or her own flapping motion, especially, an arm-raising motion is not correctly performed through the screen (game screen  200 , etc.). It is considered that this prompts the player to perform a (correct) flapping motion (motion for training) intended by the developer, et al. 
     On the other hand, when it is determined that an arm-raising motion is started, in a case that the current animation frame is not within the arm-raising-acceleration-probable section, the animation frame advances through inertia. Although detailed explanation omitted, the number of frames in a case of the arm-raising motion is also calculated according to the above-described Equation 10 and Equation 11. 
     Here, the reason why the arm-lowering-acceleration-probable section is set to equal to or more than the 15th frame and less than the 30th frame is that if the animation frame is accelerated during the period, the player feels that the player object  202  moves down the wings in synchronization with the arm-lowering motion by the player. 
     Assuming that a progress of the animation frame accelerates in the vicinity of the 37th frame to advance faster to the 45th frame, the player feels that the player object  202  moves the wing downward, and then moves the wing upward soon. That is, the player feels that an arm-raising motion is confirmed irrespective of the player performing an arm-lowering motion. 
     Furthermore, the reason why the arm-raising-acceleration-probable section is set to the section equal to or more than 30th frame and less than 60th frame is that when with respect to section equal to or more than the 45th frame and less than the 60th frame, the animation frame is accelerated during the period similar to the arm-lowering-acceleration-probable section, the player feels that the player object  202  raises the wings in synchronization with the arm-raising motion of the player. 
     In addition, the reason why the arm-raising-acceleration-probable section includes the section equal to or more than the 30th frame and less than the 45th frame is that the animation frame moves to the arm-lowering-acceleration-probable section as close as possible in preparation for the determination of the start of an arm-lowering motion of the player which is to be made several frames after. In this case, in the section equal to or more than the 30th frame and less than the 45th frame of the animation frame, to the eye, an arm-lowering animation is reproduced, and thus, the arm-lowering animation is reproduced irrespective of the player performing an arm-raising motion. However, in the flapping motion, the player performs an arm-lowering motion directly after an arm-raising motion, and therefore, by making it easy to advance the animation frame by making a projection on a next motion, it is possible to take a synchronization between the flapping motion of the player and the animation. On the contrary, the player is not required to perform an arm-raising motion directly after an arm-lowering motion. This is because an arm-lowering motion may be performed and remained as it is, and eve if the player performs an arm-raising motion, the start of the arm-raising motion may not be determined according to the above-described method, sot that there is no need of making it easy to advance the animation frame by making a projection on a next motion. 
     Furthermore, the reason why the arm-raising-acceleration-probable section includes the section equal to or more than the 30th frame and less than the 45th frame is that in the above-described cycle A, the section (hereinafter referred to as “correction section”), in which the animation frame is advanced at the 1.7-fold frame velocity before the 15th frame, is made smaller. More specifically, when the arm-raising-acceleration-probable section is long, a start of the arm-raising motion is determined during the section, the updating velocity (frame velocity) of the animation frame is accelerated, and the animation frame advances largely. Thus, the frame acceleration FrameAcc by the arm-raising motion after the arm-lowering motion by the player can be obtained, and when a start of an arm-lowering motion is determined next, the animation frame increase the chance of advancing in the vicinity of the 15th frame. That is, the correction section can be shortened. Furthermore, depending on the timing, the correction section may be lost. If the correction section is lost, the start of the arm-lowering motion is determined from the 15th frame to the 30th frame, and the animation frame is accelerated once, and then decelerated. In such a case, the flapping motion of the player and the animation are correctly synchronized with each other. 
     Although illustration is omitted, in a case that the player performs a small-flapping motion, without performing the arm-raising determination, by merely accelerating the animation frame during the arm-lowering-acceleration-probable section, it is possible to take the synchronization between the flapping motion of the player and the animation of the flapping motion of the player object  202 . This holds true for a case that the player performs a large-flapping motion. Accordingly, it is considered that a determination processing of the start of the arm-raising motion and the acceleration processing in the arm-raising-acceleration-probable section are not required to be executed. 
     However, in this embodiment, in order to take a more precise synchronization, the determination processing of the start of the arm-raising motion is performed, and the acceleration processing in the arm-raising-acceleration-probable section is executed. 
       FIG. 20  is an illustrative view showing one example of a memory map  400  of a main memory ( 42   e ,  46 ) shown in  FIG. 2 . As shown in  FIG. 20 , in a main memory ( 42   e ,  46 ), a program memory area  402  and a data memory area  404  are provided. The program memory area  402  stores a game program, and the game program is constructed of a main processing program  402   a , an image generating program  402   b , an image displaying program  402   c , a load acquiring program  402   d , a weight ratio calculating program  402   e , a barycentre calculating program  402   f , a motion judging program  402   g , a translational motion calculating program  402   h , a rotational motion calculating program  402   i , an animation synchronizing program  402   j , etc. 
     The main processing program  402   a  is a program to perform a main routine of the virtual game of this embodiment. The image generating program  402   b  is a program for generating (updating) game image data by utilizing image data  404   b  described later. The image displaying program  402   c  is a program for displaying (outputting) game image data generated according to the image generating program  402   b  as the game screen ( 200 , etc.) on the monitor  34 . 
     The load acquiring program  402   d  is a program for acquiring a current load value measured (detected) by the load controller  36 . More specifically, the load values detected by the four load sensors  36   b  are added up. In this embodiment, prior to the start of the main part of the virtual game, the body weight value of the player is detected in a state that the player rides on the load controller  36  in a static state. The numerical value data corresponding to the body weight value is acquired, and is stored in the data memory area  404  as reference value data  404   f  described later. Furthermore, during the game, a load value is detected for each game frame, and numerical value data corresponding to the detected load value is acquired, and stored as current load value data  404   g  described later in the data memory area  404 . 
     The weight ratio calculating program  402   e  is for calculating a weight ratio WR for each game frame obtained by dividing the current load value (in the current frame) acquired according to the load acquiring program  402   d  by the body weight value (reference value) of the player acquired according to the load acquiring program  402   d . The numerical value data of the weight ratio WR calculated according to the weight ratio calculating program  402   e  is stored in chronological order as weight ratio data in the weight ratio data buffer  404   a  described later. 
     The barycentre calculating program  402   f  is a program for calculating coordinate (XG, YG) of the barycentric position according to the Equation 7 and the Equation 8 by utilizing the load value in each load sensor  36   b  detected according to the load acquiring program  402   d , and storing the coordinate data corresponding to the calculate coordinate (XG, YG) as barycentric position data  404   h  described later in the data memory area  404 . 
     The motion judging program  402   g  is a program for determining a presence or absence of a flapping motion by the player and the kind of the flapping motion (large-flapping motion or small-flapping motion) on the basis of the result obtained by performing discrete Fourier transform on the time variation of the weight ratio WR calculated for each game frame for a certain period of time (30 game frames in this embodiment). 
     The translational motion calculating program  402   h  is a program for calculating a position (three-dimensional coordinate) after a certain period of time (1 game frame) of the player object  202  on the basis of a driving force obtained by a flapping motion or the y-coordinate of the barycentric position (YG) calculated according to the barycentre calculating program  402 . 
     The rotational motion calculating program  402   i  is a program for calculating a rotation amount about the x-axis of the local coordinate of the player object  202  and a rotation amount about the y-axis of the local coordinate of the player object  202  on the basis of the coordinate (XG, YG) of the barycentric position calculated according to the barycentre calculating program  402   f . The animation synchronizing program  402   j  is a program for synchronizing an animation of the flapping motion of the player object  202  with the flapping motion of the player. 
     Although illustration is omitted, the game program includes a sound output program, a backup program, etc. The sound output program is a program for generating a sound necessary for the game, such as a voice of the player object (onomatopoeic sound), a sound effect, a music (BGM), and outputting the same from the speaker  34   a . The backup program is a program for saving game data (proceeding data, result data) stored in the main memory ( 42   e ,  46 ) in the flash memory  44  and an SD card. 
       FIG. 21  shows a detailed content of the data memory area  404 . As shown in  FIG. 21 , the data memory area  404  is provided with a weight ratio data buffer  404   a . Furthermore, the data memory area  404  stores image data  404   b , large-flapping animation data  404   c , small-flapping animation data  404   d , descending-time animation data  404   e , reference value data  404   f , current load value data  404   g  and barycentric position data  404   h . In addition, the data memory area  404  is provided with a during-descending flag  404   i , a weight-ratio-declining flag  404   j , an arm-raising-determination flag  404   k , an arm-lowering-determination flag  404   m , an arm-raising-acceleration flag  404   n , an arm-lowering-acceleration flag  404   p , a large-flapping flag  404   q , a small-flapping flag  404   r , a landing-successful flag  404   s , a landing-unsuccessful flag  404   t , a game clear flag  404   u , and a game over flag  404   v.    
     The weight ratio data buffer  404   a  is a data buffer for storing in chronological order weight ratio data calculated for each game frame according to the ratio calculating program  402   e.    
     The image data  404   b  is data, such as polygon data, texture data, etc. to be used when game image data is generated according to the image generating program  402   b . The large-flapping animation data  404   c  is animation data in a case that the player object  202  performs a large-flapping motion, and is constructed of 60 pieces (frames) of the animation frame. The small-flapping animation data  404   d  is animation data in a case that the player object  202  performs a small-flapping motion, and is constructed of 60 pieces of animation frame. As described above, only a movable range of the wings is different between the large-flapping motion and the small-flapping motion. The descending-time animation data  404   e  is animation data in a case that the player object  202  is descending, and is constructed of 45 pieces of animation frame. 
     The reference value data  404   f  is numerical value data as to the load value acquired according to the load acquiring program  402   d  prior to the start of the main part of the virtual game, that is, as to the body weight value of the player. The current load value data  404   g  is numerical value data as to the current load value (in the current frame) acquired according to the load acquiring program  402   d . The barycentric position data  404   h  is coordinate data as to coordinate (XG, YG) of the current barycentric position (in the current frame) calculated according to the barycentre calculating program  402   f.    
     The during-descending flag  404   i  is a flag for determining whether or not the player object  202  is being descending, and is constructed of a one-bit register. In a case that the player object  202  is descending, the during-descending flag  404   i  is established (turned on), and a data value of “1” is set to the register. On the other hand, in a case that the player object  202  is not descending, the during-descending flag  404   i  is not established (turned off), and a data value of “0” is set to the register. 
     The weight-ratio-declining flag  404   j  is a flag for determining whether or not the weight ratio WR declines (reduces), and is constructed of a one-bit register. In a case that the weight ratio WR declines, the weight-ratio-declining flag  404   j  is turned on, and a data value of “1” is set to the register. On the other hand, in a case that the weight ratio WR does not decline, that is, in a case that the weight ratio WR rises or does not change, the weight-ratio-declining flag  404   j  is turned off, and a data value of “0” is set to the register. 
     The arm-raising-determination flag  404   k  is a flag for determining whether or not the start of the arm-raising motion is judged, and is constructed of a one-bit register. When it is determined that an arm-raising motion is started, the arm-raising-determination flag  404   k  is turned on, and a data value of “1” is set to the register. On the other hand, when it is determined an arm-lowering motion is started, the arm-raising-determination flag  404   k  is turned off, and a data value of “0” is set to the register. It should be noted that in a case that the arm-lowering-determination flag  404   m  described later is turned on as well, the arm-raising-determination flag  404   k  is turned off. 
     The arm-lowering-determination flag  404   m  is a flag for determining whether or not an arm-lowering motion is started, and is constructed of a one-bit register. When it is determined that an arm-lowering motion is started, the arm-lowering-determination flag  404   m  is turned on, and a data value of “1” is set to the register. On the other hand, when it is determined an arm-raising motion is started, the arm-lowering-determination flag  404   m  is turned off, and a data value of “0” is set to the register. It should be noted that in a case that the above-described arm-raising-determination flag  404   k  is turned on as well, the arm-lowering-determination flag  404   m  is turned off. 
     The arm-raising-acceleration flag  404   n  is a flag for determining whether or not the animation frame is accelerated in correspondence with an arm-raising motion, and is constructed of a one-bit register. When it is determined that an arm-raising motion is started, the arm-raising-acceleration flag  404   n  is turned on, and a data value of “1” is set to the register. Furthermore, when it is determined that the arm-raising motion is started, and the animation frame is accelerated, the arm-raising-acceleration flag  404   n  is turned off, and a data value of “0” is set to the register. 
     The arm-lowering-acceleration flag  404   p  is a flag for determining whether or not the animation frame is accelerated in correspondence with an arm-lowering motion, and is constructed of a one-bit register. When it is determined that an arm-lowering motion is started, the arm-lowering-acceleration flag  404   p  is turned on, and a data value of “1” is set to the register. Furthermore, it is determined that an arm-lowering motion is started, and the animation frame is accelerated, the arm-lowering-acceleration flag  404   p  is turned off, and a data value of “0” is set to the register. 
     The large-flapping flag  404   q  is a flag for determining whether or not a large-flapping motion is judged, and is constructed of a one-bit register. When a large-flapping motion is judged, the large-flapping flag  404   q  is turned on, and a data value of “1” is set to the register. On the other hand, when a large-flapping motion is not judged, the large-flapping flag  404   q  is turned off, and a data value of “0” is set to the register. It should be noted that in a case that the small-flapping flag  404   r  described later is turned on and in a case that the player performs no flapping motion as well, the large-flapping flag  404   q  is turned off. 
     The small-flapping flag  404   r  is a flag for determining whether or not a small-flapping motion is judged, and is constructed of a one-bit register. When a small-flapping motion is judged, the small-flapping flag  404   r  is turned on, and a data value of “1” is set to the register. On the other hand, if a small-flapping motion is not judged, the small-flapping flag  404   r  is turned off, and a data value of “0” is set to the register. It should be noted that in a case that the above-described large-flapping flag  404   q  is turned on, and in a case that the player performs no flapping motion as well, the small-flapping flag  404   r  is turned off. 
     The landing-successful flag  404   s  is a flag for determining whether or not the player object  202  is successful in landing in the non player object  204 , and is constructed of a one-bit register. When the player object  202  is successful in landing in the non player object  204 , the landing-successful flag  404   s  is turned on, and a data value of “1” is set to the register. On the other hand, if the player object  202  is not successful in landing in the non player object  204 , the landing-successful flag  404   s  is turned off, and a data value of “0” is set to the register. 
     The landing-unsuccessful flag  404   t  is a flag for determining whether or not the player object  202  is unsuccessful in landing in the non player object  204 , and is constructed of a one-bit register. When the player object  202  is unsuccessful in landing in the non player object  204 , the landing-unsuccessful flag  404   t  is turned on, and a data value of “1” is set to the register. On the other hand, when the player object  202  is not unsuccessful in landing in the non player object  204 , the landing-unsuccessful flag  404   t  is turned off, and a data value of “0” is set to the register. 
     The game clear flag  404   u  is a flag for determining whether or not the virtual game is to be cleared, and is constructed of a one-bit register. When the game is to be cleared, the game clear flag  404   u  is turned on, and a data value “1” is set to the register. On the other hand, when the game is not to be cleared, the game clear flag  404   u  is turned off, and a data value “0” is set to the register. 
     The game over flag  404   v  is a flag for determining whether or not the virtual game becomes a game over, is constructed of a one-bit register. When it becomes the game over, the game over flag  404   v  is turned on, and a data value of “1” is set to the register. On the other hand, when it does not become a game over, the game over flag  404   v  is turned off, and a data value of “0” is set to the register. 
     Although illustration is omitted, the data memory area  404  stores other data such as sound data, and is provided with a timer (counter) and other flags necessary for execution of the game program. 
     More specifically, the CPU  40  shown in  FIG. 2  executes entire processing according to a flowchart shown in  FIG. 22 - FIG. 25 . Although illustration is omitted, the CPU  40  performs a discrete Fourier transform processing on the time variation of the weight ratio WR every certain period of time (30 game frames) by a task separate from the entire processing. 
     As shown in  FIG. 22 , when the entire processing is started, an initial setting is executed in a step S 1 . In the step S 1 , the CPU  40  clears the weight ratio data buffer  404   a , the reference value data  404   f , the current load value data  404   g  and the barycentric position data  404   h , loads the image data  404   b , the large-flapping animation data  404   c , the small-flapping animation data  404   d  and the descending-time animation data  404   e  into the data memory area  404 , and turns each of the flags  404   i - 404   v  off. 
     In a next step S 3 , a body weight value of the player is detected, and stored as a reference value. That is, prior to the start of the main part of the virtual game, the CPU  40  acquires a sum of the load values detected in the four load sensors  36   b  as a body weight value, and stores the numerical value data as the reference value data  404   f  in the data memory area  404 . Then, in a step S 5 , the main part of the virtual game is started. 
     Succeedingly, in a step S 7 , a current load value (in the current frame) is acquired, and the acquired load value is stored. That is, the CPU  40  acquires a sum of the load values detected by the four load sensors  36   b  as a current load value, and stores the numerical value data as the current load value data  404   g  in the data memory area  404 . 
     Here, the scan time for the processing of the steps S 7 -S 79  is one game frame ( 1/60 (seconds)), so that the current load value is detected for each game frame during the virtual game. That is, the current load value data  404   g  is updated for each game frame. This is true for the barycentric position data  404   h  described next. 
     In a step S 9 , a current barycentric position is calculated, and the calculated barycentric position is stored. That is, the CPU  40  calculates the coordinate (XG, YG) of the barycentric position of the current frame according to the Equation 2 and the Equation 3 by utilizing the load value acquired from the four load sensors  36   b , and stores the coordinate data as to the coordinate (XG, YG) of the calculated barycentric position as the barycentric position data  404   h  in the data memory area  404 . 
     Succeedingly, in a step S 11 , motion judging processing (see  FIG. 26 - FIG. 28 ) described later is executed. In a next step S 13 , it is determined whether or not a large-flapping motion is performed on the basis of the result of the motion judging processing. Here, the CPU  40  determines whether or not the large-flapping flag  404   q  is turned on. If “YES” is determined in the step S 13 , that is, if the large-flapping flag  404   q  is turned on, it is determined that a large-flapping motion is performed, and in a step S 15 , to the driving force AccSim to be utilized in the integration simulation, a value obtained by multiplying the driving force Acc calculated by the weight ratio WR by 0.05 (AccSim=Acc×0.05) is set, in a step S 17 , a large-flapping animation is selected, and the process proceeds to a step S 25  shown in  FIG. 23 . 
     Alternatively, if “NO” is determined in the step S 13 , that is, if the large-flapping flag  404   q  is turned off, it is determined whether or not a small-flapping motion is performed in a step S 19 . That is, the CPU  40  determines whether or not the small-flapping flag  404   r  is turned on. If “NO” is determined in the step S 19 , that is, if a small-flapping motion is not performed, it is determined that the player performs no flapping motion, and the process proceeds to the step S 25  as it is. On the other hand, if “YES” is determined in the step S 19 , that is, if a small-flapping motion is performed, in a step S 21 , to the driving force AccSim to be utilized in the integration simulation, a value obtained by multiplying the driving force Acc calculated by the weight ratio WR by 0.0425 (AccSim=Acc×0.0425) is set, in a step S 23 , a small-flapping animation is selected, and the process proceeds to the step S 25 . 
     In the step S 25  shown in  FIG. 23 , a translational acceleration AccBoard by the barycenter in the forward and backward direction, that is, the y-coordinate of the barycentric position (YG) is calculated. In a next step S 27 , a velocity Vel_new (in the next frame) after movement of the player object  202  is calculated according to the Equation 3. Succeedingly, in a step S 29 , it is determined whether or not the velocity Vel_new is larger than a maximum velocity VelMax. If “NO” is determined in the step S 29 , that is, if the velocity Vel_new is equal to or less than the maximum velocity VelMax, the process proceeds to a step S 33  as it is. On the other hand, if “YES” is determined in the step S 29 , that is, if the velocity Vel_new is larger than the maximum velocity VelMax, the maximum velocity VelMax is set to the velocity Vel_new in a step S 31 , and the process proceeds to the step S 33 . That is, in the step S 31 , the velocity Vel_new is restricted by the maximum velocity VelMax. 
     In the step S 33 , a three-dimensional position Pos_new after movement of the player object  202  is calculated according to the Equation 4. In a next step S 35 , it is determined whether or not the player object  202  is descending. Here, the CPU  40  determines whether or not a Y component of the current velocity Vel_old of the player object  202  is less than a certain value (−0.7 in this embodiment). If “NO” is determined in the step S 35 , that is, if the Y component of the current velocity Vel_old is equal to or more than the certain value, it is determined that the player object  202  is not descending, and in a step S 39 , a rotation amount of the player object  202  is calculated on the basis of the x-coordinate (XG) and the y-coordinate (YG) of the barycentric position and, and in a step S 41 , the during-descending flag  404   i  is turned off, and the process proceeds to a step  53  shown in  FIG. 24 . 
     That is, in the step S 39 , the CPU  40  calculates the rotation amount about the x-axis of the local coordinate on the basis of the y-coordinate of the barycentric position (YG) and the rotation amount about the y-axis of the local coordinates on the basis of the x-coordinate of the barycentric position (XG). By the rotation amount about the x-axis and the rotation amount about the y-axis, a direction (Z vector (Xz, Yz, Zz)) to which the z-axis of the local coordinate of the player object  202  is applied is first decided in the three-dimensional virtual space. Next, a direction (X vector (Xx, Yx, Zx)) which is orthogonal to the Z vector, and to which the x-axis of the local coordinate extending to the direction of the left hand of the player object  202  is applied is decided. In addition, an outer product between the Z vector and the X vector is evaluated, and in the three-dimensional virtual space, a direction (Y vector (Xy, Yy, Zy)) to which the y-axis of the local coordinate of the player object  202  is applied, that is, a unit vector AccDir is decided. Here, each of the X vector, the Y vector, and the Z vector is a unit vector of a magnitude “1”. 
     On the other hand, if “YES” is determined in the step S 35 , that is, if the Y component of the current velocity Vel_old is less than the certain value, it is determined that the player object  202  is descending, and in a step S 36 , a rotation amount of the player object  202  is calculated on the basis of the x-coordinate of the barycentric position (XG), and in a step S 37 , an animation during descending of the player object  202  is selected, and the process proceeds to a step S 43  shown in  FIG. 24 . 
     That is, in the step S 36 , the CPU  40  calculates only the rotation amount about the y-axis of the local coordinate of the player object  202  on the basis of the x-coordinate of the barycentric position (XG), and decides a direction (z vector) to which the z-axis of the local coordinate of the player object  202  is applied in the three-dimensional virtual space. Thereafter, as described above, a direction (x vector) to which the x-axis of the local coordinate of the player object  202  is applied in the three-dimensional virtual space is decided. In addition, a direction (y vector) to which the y-axis of the local coordinate of the player object  202  is applied in the three-dimensional virtual space is decided. 
     In the step S 43  shown in  FIG. 24 , it is determined whether or not the during-descending flag  404   i  is turned off. That is, the CPU  40  determines whether or not the player object  202  starts to descend. If “YES” is determined in the step S 43 , that is, if the during-descending flag  404   i  is turned off, it is determined that that the player object  202  starts to descend, the during-descending flag  404   i  is turned on in a step S 45 , and an initial value (0 in this embodiment) of the frame number is set to the animation frame Frame_new in a step S 47 , an animation of the decided animation frame Frame_new is set in a step S 51 , and then, the process proceeds to a step S 59  shown in  FIG. 25 . 
     On the other hand, if “NO” is determined in the step S 43 , that is, if the during-descending flag  404   i  is turned on, it is determined that the player object  202  has already been descending, in a step S 49 , 1 is added to the animation frame Frame_new, and the process proceeds to the step S 51 . Here, if the current value of the animation frame Frame_new is “44”, that is, if the animation frame is the last frame, when the animation frame Frame_new is added by one in the step S 49 , the value is set to “0”. That is, the frame number of the animation frame is returned to the initial value. 
     Furthermore, as shown in  FIG. 23 , in a case that the player object  202  is not descending, “NO” is determined in the step S 37 , the during-descending flag  404   i  is turned off in a step S 41 , and then, it is determined whether or not the flapping animation (large-flapping animation and small-flapping animation) selected in the step S 17  or the S 23  is different from the current flapping animation in the step S 53 . If “NO” is determined in the step S 53 , that is, if the selected flapping animation and the current flapping animation match with each other, the process proceeds to a step S 57  as it is. On the other hand, if “YES” is determined in the step S 53 , that is, if the selected flapping animation and the current flapping animation are different from each other, the flapping animation is switched in a step S 55 , and the process proceeds to the step S 57 . 
     It should be noted that in the step S 55 , the animation is merely switched, but if the switching is abruptly made between the large-flapping animation and the small-flapping animation, the player watching the game screen  200  may have uncomfortable feeling. Thus, in this embodiment, these animations are configured to be blended. Briefly speaking, in a case that the large-flapping animation is switched to the small-flapping animation, both of the animations are reproduced. For example, at the moment of switching the animation, the reproduction ratio of the large-flapping motion is 1.0, and the reproduction ratio of the small-flapping motion is 0.0. Here, the large-flapping animation and the small-flapping animation are coincident with each other in the frame number of the animation frame. The reproduction ratio is varied for a certain period of time (30 game frames=0.5 seconds in this embodiment) gradually (linearly or step-by-step, for example), that is, the reproduction ratio of the large-flapping motion is reduced while the reproduction ratio of the small-flapping motion is increased. When a certain period of time elapses from the start of switching the animation (the 30th game frame for example), the reproduction ratio of the large-flapping motion becomes 0.0, and the reproduction ratio of the small-flapping motion becomes 1.0. Thus, the large-flapping animation is switched to the small-flapping animation. Although an explanation is omitted, this is true for a case that the small-flapping animation is switched to the large-flapping animation. 
     Returning to  FIG. 24 , in the step S 57 , synchronizing processing ( FIG. 29 - FIG. 31 ) described later is executed. Succeedingly, in the step S 59  shown in  FIG. 25 , it is determined whether or not the player object  202  is successful in landing in a predetermined place. Here, the CPU  40  determines whether or not the player object  202  lands in the non player object  204  to be landed. Although detailed explanation is omitted, the non player object  204  to be landed is set in advance, or is variably set in correspondence with the progress of the virtual game. Here, the CPU  40  determines whether or not the player object  202  is on, that is, lands in the non player object  204  by performing a hit determination between the player object  202  and the non player object  204  to be landed. 
     If “YES” is determined in the step S 59 , that is, if it is determined that the player object  202  is successful in landing in the predetermined place, if the landing-successful flag  404   s  is turned on in a step S 61 , and the process proceeds to a step S 67 . If “NO” is determined in the step S 59 , that is, if the player object  202  is flying, falls in the sea, lands again in the non player object  204  where the player object  202  has already been landed in, it is determined that the player object  202  is not successful in landing the predetermined place, and in a step S 63 , it is determined whether or not the player object  202  is unsuccessful in landing in the predetermined place. Here, the CPU  40  determines whether or not the player object  202  lands in a non player object  204  except for the non player object  204  to be landed or falls in the sea surrounding the non player object  204 . 
     If “NO” is determined in the step S 63 , that is, if the player object  202  is flying, it is determined that the player object  202  is not unsuccessful in landing in the predetermined place, and the process proceeds to the step S 67 . On the other hand, if “YES” is determined in the step S 63 , that is, if the player object  202  lands in the non player object  204  except for the non player object  204  to be landed, or the player object  202  falls in the sea surrounding the non player object  204 , it is determined that the player object  202  is unsuccessful in landing in the predetermined place, in a step S 65 , the landing-unsuccessful flag  404   t  is turned on, and the process proceeds to a step S 71  as it is. 
     In the step S 67 , it is determined whether or not a game is to be cleared. That is, the CPU  40  determines whether or not the player object  202  reaches the goal via all the predetermined landing places. If “YES” is determined in the step S 67 , that is, if the game is to be cleared, the game clear flag  404   u  is turned on in a step S 69 , and the process proceeds to a step S 75 . 
     On the other hand, if “NO” is determined in the step S 67 , that is, if the game is not to be cleared, it is determined whether a game is to be over in the step S 71 . Here, the CPU  40  determines whether or not the time limit expires before the player object  202  reaches the goal, whether or not the player object  202  fails in landing by a predetermined number of times (3 times, for example), or whether or not a time during which the player object  202  falls in the sea is above a predetermined time (10 seconds, for example). If “NO” is determined in the step S 71 , that is, if the game is not to be over, the process directly proceeds to the step S 75 . On the other hand, if “YES” is determined in the step S 71 , that is, if the game is to be over, the game over flag  404   v  is turned on in a step S 73 , and the process proceeds to the step S 75 . 
     In the step S 75 , a game image is generated. Here, the CPU  40  arranges the player object  202  in the three-dimensional virtual space according to the determinant A shown in the Equation 6, and draws (updates) the game image by reading the animation of the animation frame set in the step S 51  from the descending-time animation data  404   c , and reading the animation of the animation frame set in the synchronizing processing in the step S 57  from the flapping animation data ( 404   c ,  404   d ). Furthermore, a background image including the non player object  204  is drawn (updated). In addition, if the landing-successful flag  404   s , the landing-unsuccessful flag  404   t , the game clear flag  404   u  or the game over flag  404   v  is turned on, an image representing successful landing, unsuccessful landing, game clear or game over is generated. For example, a text indicating successful landing, unsuccessful landing, game clear or game over overwrites the game image. At this time, although illustration is omitted, a sound effect or music in correspondence with successful landing, unsuccessful landing, game clear or game over is output. 
     In a next step S 77 , the game image is displayed. That is, the CPU  40  displays the game image generated (updated) in the step S 75  as a game screen ( 200 , etc.) on the monitor  34 . Then, in a step S 79 , it is determined whether the game is to be ended or not. Here, the CPU  40  determines whether or not a game end is instructed according to an operation by the player. If “NO” is determined in the step S 79 , that is, if the game is not to be ended, the process returns to the step S 7  shown in  FIG. 22 . However, if the game is to be over, the virtual game is started from the top. On the other hand, if “YES” is determined in the step S 79 , that is, if the game is to be ended, the entire processing is ended as it is. 
     Although illustration is omitted, the landing-successful flag  404   s  and the landing-unsuccessful flag  404   t  are turned off from the step S 75  to when the process returns to the step S 7  in response to “NO” being determined in the step S 79 . 
       FIG. 26 - FIG. 28  is a flowchart showing motion judging processing in the step S 11  shown in  FIG. 22 . As shown in  FIG. 26 , when starting the motion judging processing, the CPU  40  calculates and stores the current weight ratio WR in a step S 91 . That is, a current weight ratio WR is calculated by dividing the load value indicated by current load value data  404   g  by the reference value (body weight value) indicated by the reference value data  404   f , and the weight ratio data is stored in the weight ratio data buffer  404   a.    
     In a next step S 93 , it is determined whether or not the current weight ratio WR is less than a first threshold value (0.985 in this embodiment). That is, the CPU  40  determines whether or not a driving force Acc is to be applied to the player object  202 . If “YES” is determined in the step S 93 , that is, if the current weight ratio WR is less than the first threshold value, 1-weight ratio WR is set to the driving force Acc in a step S 95 , and the process proceeds to a step S 99 . That is, the driving force Acc in correspondence with the weight ratio WR is calculated (set). On the other hand, if “NO” is determined in the step S 93 , that is, if the current weight ratio WR is equal to or more than the first threshold value, 0 is set to the driving force Acc in a step S 97 , and the process proceeds to the step S 99 . 
     In the step S 99 , it is determined whether or not the maximum value of the weight ratio WR in an immediately-preceding flapping motion (flapping section) is larger than a second threshold value (1.3 in this embodiment). That is, the CPU  40  determines whether or not an operation input by the player is performed by bending and stretching exercises. It should be noted that the immediately-preceding flapping section means a section from when the start of the last-but-one-arm-lowering motion is determined to when the start of the previous (immediately-preceding)-arm-lowering motion is determined. 
     If “NO” is determined in the step S 99 , that is, if the maximum value of the weight ratio WR in the immediately-preceding flapping motion is equal to or less than the second threshold value, it is determined that the operation input by the player is not performed by the bending and stretching exercises, the maximum velocity VelMax is set to the highest velocity (4 in this embodiment) of the player object  202  in a step S 101 , the driving force Acc is multiplied by 1.3 (Acc=Acc×1.3) in a step S 103 , and then, the process proceeds to a step S 109 . On the other hand, if “YES” is determined in the step S 99 , that is, if the maximum value of the weight ratio WR in the immediately-preceding flapping motion is larger than the second threshold value, it is determined that the operation input by the player is performed by the bending and stretching exercises, in a step S 105 , the maximum velocity VelMax is set to the half the highest velocity (2 in this embodiment) of the player object  202 , in a step S 107 , the driving force Acc is multiplied by 0.8 (Acc=Acc×0.8), and the process proceeds to the step S 109 . 
     Thus, in the steps S 99 -S 107 , in a case of an operation input intended by the developer, et al. of the virtual game, the player object  202  is configured to be easily advanced, and on the contrary thereto, in a case of an operation input not intended by the developer, et al., the player object  202  is configured not to be easily advanced. Accordingly, the numerical value set to the maximum velocity VelMax and the coefficient to be multiplied by the driving force Acc are not required to be restricted to the values in this embodiment. 
     In the step S 109 , it is determined whether or not the difference between the current weight ratio WR (in the current frame) and the previous weight ratio WR (in the previous frame) is less than a third threshold value (0.001 in this embodiment). If “YES” is determined in the step S 109 , that is, if the difference between the current weight ratio WR and the previous weight ratio WR is less than the third threshold value, it is determined whether or not the current weight ratio WR is equal to or more than a fourth threshold value (0.99 in this embodiment) and equal to or less than a fifth threshold value (1.01 in this embodiment) in a step S 111  shown in  FIG. 27 . 
     If “YES” is determined in the step S 111 , that is, if the current weight ratio WR is equal to or more than the fourth threshold value and equal to or less than the fifth threshold value, it is determined that weight ratio WR does not rise or decline, and the motion judging processing is ended as it is as shown in  FIG. 28 . On the other hand, if “NO” is determined in the step S 111 , that is, if the current weight ratio WR is less than the fourth threshold value, or more than the fifth threshold value, the process proceeds to a step S 137  shown in  FIG. 28  as it is. Although illustration is omitted, in such a case, the previous determination result as to the rise and decline of the weight ratio WR is maintained. 
     Returning to  FIG. 26 , if “NO” is determined in the step S 109 , that is, if the difference between the current weight ratio WR and the previous weight ratio WR is equal to or more than the third threshold value, it is determined that the current weight ratio WR is smaller than the previous weight ratio WR in a step S 113  shown in  FIG. 27 . That is, the CPU  40  determines whether or not the weight ratio WR declines or rises. If “NO” is determined in the step S 113 , that is, if the current weight ratio WR is larger than the previous weight ratio WR, it is determined that the weight ratio WR rises, and it is determined whether or not the weight-ratio-declining flag  404   j  is turned on in a step S 115 . That is, the CPU  40  determines whether or not the weight ratio WR declines and then rises. 
     If “NO” is determined in the step S 115 , that is, if the weight-ratio-declining flag  404   j  is turned off, it is determined that the weight ratio WR is rising, and the process proceeds to the step S 137  as it is. On the other hand, if “YES” is determined in the step S 115 , that is, if the weight-ratio-declining flag  404   j  is turned on, it is determined that the weight ratio WR declines and then rises, in a step S 117 , the weight-ratio-declining flag  404   j  is turned off, and in a step S 119 , it is determined whether or not the current weight ratio WR is equal to or more than a sixth threshold value (0.98 in this embodiment). That is, it is determined whether or not an arm-raising motion intended by a developer, et al. is performed. 
     If “NO” is determined in the step S 119 , that is, if the current weight ratio WR is less than the sixth threshold value, it is determined not to be an arm-raising motion, and the process proceeds to the step S 137  as it is. On the other hand, if “YES” is determined in the step S 119 , that is, if the current weight ratio WR is equal to or more than the sixth threshold value, it is determined to be an arm-raising motion, in a step S 121 , the arm-raising-determination flag  404   k  is turned on, in a step S 123 , the arm-raising-acceleration flag  404   n  is turned on, in a step S 125 , the arm-lowering-determination flag  404   m  is turned off, and the process proceeds to the step S 137 . 
     Alternatively, if “YES” is determined in the step S 113 , that is, if the current weight ratio WR is smaller than the previous weight ratio WR, it is determined that the weight ratio WR declines, the weight-ratio-declining flag  404   j  is turned on in a step S 127 , and it is determined whether or not the current weight ratio WR is less than a seventh threshold value (0.985 in this embodiment) in a step S 129 . That is, the CPU  40  determines whether an arm-lowering motion or not. If “NO” is determined in the step S 129 , that is, if the current weight ratio WR is equal to or more than the seventh threshold value, it is determined not to be an arm-lowering motion, and the process proceeds to the step S 137  as it is. On the other hand, if “YES” is determined in the step S 129 , that is, if the current weight ratio WR is less than the seventh threshold value, it is determined to be an arm-lowering motion, in a step S 131 , the arm-lowering-determination flag  404   m  is turned on, in a step S 133 , the arm-lowering-acceleration flag  404   p  is turned on, in a step S 135 , the arm-raising-determination flag  404   k  is turned off, and the process proceeds to the step S 137 . 
     As shown in  FIG. 28 , in the step S 137 , it is determined whether or not the amplitude A is maximum at the index number n=2 of the frequency and the amplitude A at the index number n=3 is equal to or more than an eighth threshold value (0.0001, here), or whether or not the amplitude A is maximum at the index number n=3 or more of the frequency. If “YES” is determined in the step S 137 , that is, if the amplitude A is the maximum at the index number n=2 of the frequency and the amplitude A at the index number n=3 is equal to or more than the eighth threshold value, or if the amplitude A is the maximum at the index number n=3 or more of the frequency, it is determined to be a small-flapping motion, the small-flapping flag  404   r  is turned on in a step S 139 , the large-flapping flag  404   q  is turned off in a step S 141 , and the process returns to the entire processing. 
     On the other hand, if “NO” is determined in the step S 137 , that is, if the amplitude A is not the maximum at the index number n=2 of the frequency, if the amplitude A at the index number n=3 is less than the eighth threshold value, or if the amplitude A is not the maximum at the index number n=3 or more of the frequency, all the amplitudes A at the index numbers n=1-15 of the frequency are less than the eighth threshold value in a step S 143 . 
     If “NO” is determined in the step S 143 , that is, if there is the amplitude A being equal to or more than the eighth threshold value out of the amplitudes A at the index number n=1-15 of the frequency, it is determined to be a large-flapping motion, the large-flapping flag  404   q  is turned on in a step S 145 , the small-flapping flag  404   r  is turned off in a step S 147 , and the process returns to the entire processing. 
     On the other hand, if “YES” is determined in the step S 143 , that is, if all the amplitudes A at the index number n=1-15 of the frequency are less than the eighth threshold value, it is determined that no flapping motion is performed, and in a step S 149 , the large-flapping flag  404   q  and the small-flapping flag  404   r  are turned off, and the process returns to the entire processing. 
       FIG. 29 - FIG. 31  is a flowchart showing synchronizing processing shown in the step S 57  in  FIG. 24 . As shown in  FIG. 29 , when starting the synchronizing processing, the CPU  40  determines whether or not the arm-lowering-determination flag  404   m  is turned on in a step S 161 . Although detailed explanation is omitted, in the synchronizing processing, the player object  202  is not descending, but a flapping motion is performed by the player, and therefore, the arm-raising-determination flag  404   k  or the arm-lowering-determination flag  404   m  is sure to be turned on. 
     If “NO” is determined in the step S 161 , that is, if the arm-lowering-determination flag  404   m  is turned off, and the arm-raising-determination flag  404   k  is turned on, the process proceeds to a step S 181  shown in  FIG. 30 . On the other hand, if “YES” is determined in the step S 161 , that is, the arm-lowering-determination flag  404   m  is turned on and the arm-raising-determination flag  404   k  is turned off, it is determined whether or not the arm-lowering-acceleration flag  404   p  is turned on in a step S 163 . That is, the CPU  40  determines whether or not the animation frame is accelerated in response to the start of the arm-lowering motion by the player. 
     If “NO” is determined in the step S 163 , that is, if the arm-lowering-acceleration flag  404   p  is turned off, it is determined that the animation frame has already been accelerated in response to the start of the arm-lowering motion in the current flapping section, 0 is set to the frame acceleration FrameAcc in a step S 165 , and the process proceeds to a step S 193  shown in  FIG. 31 . On the other hand, if “YES” is determined in the step S 163 , that is, if the arm-lowering-acceleration flag  404   p  is turned on, it is determined that the animation frame has not yet been accelerated in response to the start of the arm-lowering motion in the current flapping section, and it is determined whether or not the current animation frame is equal to or more than the 15th frame and less than the 30th frame in a step S 167 . That is, the CPU  40  determines whether or not the animation frame is within the arm-lowering-acceleration-probable section. 
     If “YES” is determined in the step S 167 , that is, if the current animation frame is equal to or more than the 15th frame and less than the 30th frame, it is determined that the animation frame is within the arm-lowering-acceleration-probable section, and in a step S 169 , a value obtained by dividing the maximum number of frames AnimFrameMax of the animation frame by the arm-lowering determination cycle CycleSwing is set to the frame acceleration FrameAcc. That is, when the frame velocity FrameVel_new is calculated thereafter, the animation frame is accelerated in a next step S 171 , the arm-lowering-acceleration flag  404   p  is turned off, and the process proceeds to the step S 193 . 
     On the other hand, if “NO” is determined in the step S 167 , that is, if the current animation frame is not equal to or more than the 15th frame and less than the 30th frame, it is determined that the animation frame is not within the arm-lowering-acceleration-probable section, 0 is set to the frame acceleration FrameAcc in a step S 173 , and a value obtained by dividing the 1.7-fold maximum number of frames AnimFrameMax of the animation frame by the arm-lowering determination cycle CycleSwing is set to the current frame velocity FrameVel_old according to the Equation 12 in a step S 175 . That is, the CPU  40  makes the animation frame close to the arm-lowering-acceleration-probable section faster. 
     Succeedingly, in a step S 177 , it is determined whether or not the current frame velocity FrameVel_old is larger than 6. If “NO” is determined in the step S 177 , that is, if the current frame velocity FrameVel_old is equal to or less than 6, the process proceeds to the step S 193  as it is. On the other hand, if “YES” is determined in the step S 177 , that is, if the current frame velocity FrameVel_old is more than 6, 6 is set to the current frame velocity FrameVel_old in a step S 179 , and the process proceeds to the step S 181 . That is, current frame velocity FrameVel_old is restricted. 
     As shown in  FIG. 30 , in the step S 181 , it is determined whether or not the arm-raising-acceleration flag  404   n  is turned on. If “NO” is determined in the step S 181 , that is, if the arm-raising-acceleration flag  404   n  is turned off, it is determined that the animation frame has already been accelerated in response to the start of the arm-raising motion in the current flapping section, in a step S 191 , 0 is set to the frame acceleration FrameAcc, and the process proceeds to the step S 193 . On the other hand, if “YES” is determined in the step S 181 , that is, if the arm-raising-acceleration flag  404   n  is turned on, it is determined that the animation frame has not yet been accelerated in response to the start of the arm-raising motion in the current flapping section, and it is determined whether or not the current animation frame is equal to or more than the 30th frame and less than the 60th frame in a step S 183 . That is, the CPU  40  determines whether or not the animation frame is within the arm-raising-acceleration-probable section. 
     If “NO” is determined in the step S 183 , that is, if the current animation frame is not equal to or more than the 30th frame and less than the 60th frame, it is determined that the animation frame is not within the arm-raising-acceleration-probable section, and the process proceeds to the step S 191 . On the other hand, if “YES” is determined in the step S 183 , that is, if the current animation frame is equal to or more than the 30th frame and less than the 60th frame, it is determined that the animation frame is within the arm-raising-acceleration-probable section, and in a step S 185 , it is determined whether or not the current frame velocity FrameVel_old is less than 2. 
     If “NO” is determined in the step S 185 , that is, if the current frame velocity FrameVel_old is equal to or more than 2, the process proceeds to the step S 191 . On the other hand, if “YES” is determined in the step S 185 , that is, if the current frame velocity FrameVel_old is less than 2, 2 is set to the frame acceleration FrameAcc in a step S 187 , the arm-raising-acceleration flag  404   n  is turned off in a step S 189 , and the process proceeds to the step S 193 . 
     In the step S 193  shown in  FIG. 31 , it is determined whether or not the frame acceleration FrameAcc is not 0. If “NO” is determined in the step S 193 , that is, if the frame acceleration FrameAcc is 0, the process proceeds to a step S 197  as it is. On the other hand, if “YES” is determined in the step S 193 , that is, if the frame acceleration FrameAcc is not 0, 0 is set to the current frame velocity Frame Vel_old in a step S 195 , and the process proceeds to the step S 197 . 
     In the step S 197 , according to the integration simulation, a next frame velocity FrameVel_new is calculated. Succeedingly, in a step S 199 , the next animation frame Frame_new is decided. That is, the CPU  40  calculates the next frame velocity FrameVel_new according to the Equation 10, and calculates the next animation frame Frame_new according to the Equation 11. Then, in a step S 201 , the animation at the decided animation frame Frame_new is set, and the process returns to the entire processing shown in  FIG. 22 - FIG. 25 . 
     According to the embodiment, a flapping motion of the player is determined on the basis of the cycle of the variation of the weight ratio, this is reflected on the animation of the player object, and the moving amount of the player object is controlled on the basis of the magnitude of the weight ratio, and therefore, it is possible to execute wide variety of processing in comparison with a case that the game processing is merely executed in accordance with the variation of the load. 
     Furthermore, according to this embodiment, the updating velocity of the animation frame is changed according to an arm-lowering motion and an arm-raising motion, and therefore, it is possible to smoothly synchronize the flapping motion of the player and the animation by canceling the delay of the animation frame. Thus, the player can absorb in the virtual game, and enjoy playing the game play. 
     In addition, according to this embodiment, in a case that the weight ratio based on the load value of the player is equal to or more than the predetermined threshold value, when it is detected that the weight ratio locally declines (decreases) and increases, it is determined that an arm-raising motion in the large-flapping motion is started, and the moving velocity of the player object is changed in accordance with the arm-raising motion, and the updating velocity of the animation frame is changed in accordance with the arm-raising motion as well as the arm-lowering motion, so that it is possible to make the player perform a motion that the developer, et al. intended, and perform the processing in response to the detection of such a motion. That is, it is possible to execute wide variety of processing by detecting a complex motion. 
     Additionally, in this embodiment, the weight ratio obtained by dividing the current load value by the body weight value (reference value) is utilized, but the load value may be used as it is. In such a case, in order to eliminate advantage and disadvantage due to the difference in the weight of the player, a threshold value may be provided for each weight (for each rank of the weights). 
     Furthermore, in this embodiment, on the basis of the frequency spectrum obtained by performing a discrete Fourier transform on the time variation of the weight ratio, the presence or absence of a flapping motion by the player and the kind of the flapping motion are determined, but a fast Fourier transform may be executed. 
     In addition, in this embodiment, in a repeating motion, such as a flapping motion, an arm-raising motion of the player is determined on the basis of the time variation of the weight ratio as shown in  FIG. 13 , but there is no need of being restricted to this. For example, when a waveform obtained by reversing upside down the waveform shown in  FIG. 13  at the reference value of the weight ratio is acquired, a predetermined motion is determined on the basis of the waveform reversed upside down. In such a case, when the value of the weight ratio is equal to or less than the certain value (1.02, for example), and the weight ratio rises and then declines, it is determined that the predetermined motion is started. 
     Although the present invention has been described and illustrated in detail, it is clearly understood that the same is by way of illustration and example only and is not to be taken by way of limitation, the spirit and scope of the present invention being limited only by the terms of the appended claims.