JP2003275460A - Game device and information storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a game device and an information storage medium capable of realizing real expression of reflection in a reflection area of light from a light source by a little processing load. <P>SOLUTION: A reflected image object is set in a position P2 of perspectively transforming a plane symmetrical position P1 with respect to a light source position on a screen in regard to a map face, and the reflected image object is overwritten on a frame image. An outline and luminance distribution of the reflected image object are fluctuated following passage of time. A reflection permission flag RF showing whether or not a reflection calculating process is permitted is set with respect to each dot of a map 30. A width and luminance of the reflection area is controlled in response to an altitude difference between a view point position and the position P1. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a game device and an information storage medium.

[0002]

2. Description of the Related Art Conventionally, there is known a game device in which a plurality of objects are arranged in an object space which is a virtual three-dimensional space and an image viewed from a given viewpoint in the object space is generated. It is very popular for experiencing reality. In the case of a game device that allows players to enjoy the control of a fighter, for example, a player causes a fighter operated by the player to fly in an object space and play a game by playing against a fighter operated by another player or a computer. have fun.

[0003]

[Patent Document 1] Japanese Patent Laid-Open No. 60-250479

[0004]

In such a game device, it is an important technical subject to generate a more realistic image in order to improve the virtual reality of the player. Therefore, for example, the glitter of the water surface (map in a broad sense) caused by the reflection of light from the sun (glitter)
It is desirable that such images can be expressed with realistic images. Then, as a method of expressing the sparkle of the water surface, for example, the first and second methods shown in FIGS. 1A and 1B can be considered.

The first method shown in FIG. 1 (A) is to simulate the glitter of the water surface faithfully in the real world. In this first method, the normal vectors 911 to 9
A plurality of polygons 901 to 907 in which 17 is oriented in various directions
The water surface 900 is constituted by the above, and the water surface 900 is provided with undulations. Then, the polygons 901 to 9 forming the water surface 900
Reflection calculation processing for expressing specular reflection is performed based on the 07 normal vectors 911 to 917 and the light source vector 920 from the light source (sun).

However, in order to express the sparkle of the water surface by this first method, it is necessary to change the direction of the surfaces of the polygons 901 to 907 (directions of the normal vectors 911 to 917) with the passage of time. Further, the processing load of the reflection calculation processing based on the normal vectors 911 to 917 and the light source vector 920 is also very heavy. Therefore, the first method is suitable for generating a CG (movie) image or the like that does not require real-time processing, but is not suitable for generating a game image that requires real-time processing.

In the second method shown in FIG. 1B, the glitter of the water surface is expressed by animating the texture representing the water surface over time. According to the second method, a realistic image can be generated with a small processing load in a game in which the moving range of the viewpoint position is strongly limited or in a game in which the reflection area in which the glitter occurs is fixed.

However, the second method of FIG. 1B is for a game in which the moving range of the viewpoint position is not limited,
This is a technique unsuitable for a game in which the reflection area causing a sparkle moves to an arbitrary place as the viewpoint position moves. This is because in such a game, the location of the reflection area where the texture is animated changes.
Therefore, even in such a game, the emergence of a technique capable of realistically expressing the sparkle of the water surface is desired.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a game device which can realize a realistic expression of the reflection of light from a light source with a small processing load. And to provide an information storage medium.

[0010]

In order to solve the above problems, the present invention is a game device for generating an image, and permits a reflection calculation process for expressing reflection of light from a light source. A means for storing map image information in which a reflection permission flag indicating whether or not each dot of the map is set, a means for setting a reflection area based on a light source position and a viewpoint position, Means for performing the reflection calculation process on the dots for which the reflection permission flag is turned on in the reflection area.

An information storage medium according to the present invention is characterized by including information for realizing the above means.

In the present invention, the reflection permission flag indicating whether or not the reflection calculation processing is permitted is set for each dot of the map. Further, the reflection area is set based on the light source position and the viewpoint position. Then, the reflection calculation processing for expressing the reflection of the light from the light source is performed on the dots for which the reflection permission flag is turned on in the set reflection area. That is, it becomes possible to perform the reflection calculation processing only in the region (for example, the water surface) where the reflection of the light from the light source is required to be expressed. The reflection permission flag is set for each dot in the map, and the reflection area moves as the light source position and the viewpoint position move. Therefore, even if the movement range of the viewpoint position is not limited and the reflection area moves to an arbitrary place along with the movement of the viewpoint position, a realistic expression of light reflection in the reflection area can be obtained with a small processing load. Can be realized in.

It should be noted that both the setting of the reflection area in the object space and the setting of it on the screen (display screen) are included in the scope of the present invention. Further, it is within the scope of the present invention to set the reflection permission flag to each dot of the texture mapped to the map and to set each color of the texture palette.

In the game device and the information storage medium according to the present invention, in the first area of the map, the reflection permission flag is almost completely turned off, and in the second area of the map, the reflection permission flag is set. It is characterized in that dots whose flags are turned on are scattered. In this way, the dots that reflect light will be interspersed with the dots that do not reflect light. As a result, it is possible to make the light from the light source appear to be irregularly reflected on the undulations of the map surface without actually having the undulations on the map surface.

In the first area of the map as well, it is desirable to turn on the reflection permission flag for the portion where it is desirable to express light reflection.

Further, the game device and the information storage medium according to the present invention, for each dot of the frame buffer when a frame image obtained by perspective-transforming a display object including a map is written in the frame buffer. The reflection permission flag is written, and the reflection calculation process is performed based on the reflection permission flag written in the frame buffer. By doing this, when the positional relationship between the viewpoint position or the line-of-sight direction and the map changes, the reflection permission flag of the dot at the same location is written or written in the frame buffer due to the deformation of the image information by perspective transformation. Or not. As a result, the reflection calculation process may or may not be performed on the dots at the same location. As a result, the dots at the same place will appear to reflect light or not to reflect light, and a realistic image representation will be possible with a small processing load.

Further, the game device and the information storage medium according to the present invention are characterized in that the width of the reflection area becomes narrower or the brightness of the reflection area becomes higher as the incident angle of the light from the light source becomes larger. With this configuration, the width and the brightness of the reflection area are changed according to the incident angle of the light from the light source, and the realism of the image can be improved.

It should be noted that it is also within the scope of the present invention to control the width and the brightness of the reflection area based on a parameter mathematically equivalent to the incident angle, instead of controlling it based on the incident angle itself.

Further, in the game device and the information storage medium according to the present invention, when the reflection area goes out of the screen,
The reflection calculation process in the reflection area is omitted. By doing so, it is possible to prevent unnecessary processing from being performed when the reflective area goes out of the screen, and to reduce the processing load.

Further, the game apparatus and the information storage medium according to the present invention are characterized in that the brightness of the reflection area becomes lower as the distance between the viewpoint position and the map increases. By doing so, it is possible to prevent the reflection area from being conspicuously seen when the distance between the viewpoint position and the map is large.

Even if the brightness of the reflection area is not controlled based on the distance between the viewpoint position and the map itself, but is controlled based on a parameter mathematically equivalent to this distance,
Included within the scope of the invention.

The present invention is also a game device for generating an image, wherein means for storing map image information and a first position plane-symmetric with respect to a light source position with respect to a map surface are obtained, Second perspective conversion of the position of the
Means for setting the reflection image object at the position of
To perform reflection calculation processing for expressing reflection of light from a light source by overwriting the reflection image object on a frame image obtained by perspectively transforming a display object including a map on a screen. And means.

An information storage medium according to the present invention is characterized by containing information for realizing the above means.

According to the present invention, the second position obtained by perspectively transforming the first position, which is plane-symmetric with respect to the light source position with respect to the map surface, to the screen is obtained, and the reflection image object is set at this second position. . Then, the reflection calculation processing is performed by overwriting the reflection image object on the frame image. As described above, according to the present invention, the reflection calculation processing can be realized without disposing the reflection image object in the object space. Then, the second position, which is the position where the reflection image object is set, can also be obtained only by perspectively transforming the first position. Although not particularly limited, it is possible to omit the process of changing the size of the reflection image object in the depth direction according to the line-of-sight direction. Therefore, it is possible to represent a realistic image while reducing the processing load as compared with the method of arranging the three-dimensional reflection image object in the object space.

Further, the game device and the information storage medium according to the present invention are characterized in that a reflection permission flag indicating whether or not the reflection calculation processing is permitted is set for each dot of the map. By doing so, the reflection calculation process is performed on the dots for which the reflection permission flag is turned on. That is, the reflection calculation processing can be performed only in the region where the reflection of the light from the light source is required to be expressed. Therefore, even when the moving range of the viewpoint position is not limited, it is possible to realize a realistic expression of light reflection in the area where the reflection image object is set with a small processing load.

In the game device and the information storage medium according to the present invention, at least one of the width of the reflection image object and the brightness of the reflection image object is controlled according to the altitude difference between the viewpoint position and the first position. It is characterized by being done. By doing so, it is possible to change the width and the brightness of the reflection image object according to the incident angle without directly obtaining the incident angle of the light from the light source. Therefore, the processing for obtaining the incident angle can be omitted, and the processing load can be reduced. Further, by controlling the brightness of the reflection image object according to the altitude difference, it is possible to realize the processing of lowering the brightness of the reflection image object when the distance between the viewpoint position and the map is long.

Further, the game device and the information storage medium according to the present invention are characterized in that at least one of the contour and the luminance distribution of the reflection image object fluctuates over time. This makes it possible to make the boundary of the reflection image object inconspicuous. In addition, even when the viewpoint position is stationary, a realistic image expression can be realized.

[0028]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the present invention will be described below with reference to the drawings. In the following, a case where the present invention is applied to a fighter game (flight simulator) will be described as an example, but the present invention is not limited to this and can be applied to various games. In the following, the case where one or a plurality of primitive surfaces forming an object are polygons will be described as an example, but the present invention is not limited to this, and primitive surfaces other than polygons (for example, curved surfaces)
It can also be applied to the case of configuring an object by

1. Configuration FIG. 2 shows an example of a block diagram of this embodiment. In the figure, the game device of this embodiment may include at least the processing unit 100 (or the processing unit 100 and the storage unit 140, or the processing unit 100, the storage unit 140, and the information storage medium 150), and other blocks ( For example, the operation unit 13
0, image generation unit 160, display unit 162, sound generation unit 17
0, sound output unit 172, communication unit 174, I / F unit 176,
The memory card 180, etc.) can be an arbitrary component.

Here, the processing section 100 controls the entire apparatus,
The CPU (C) performs various kinds of processing such as instruction of commands to each block in the device and game calculation.
It can be realized by hardware such as ISC type, RISC type), DSP, ASIC (gate array, etc.) or a given program (game program).

The operation unit 130 is for the player to input operation information, and its function can be realized by hardware such as levers and buttons.

The storage section 140 includes a processing section 100, an image generation section 160, a sound generation section 170, a communication section 174, and an I / F section 1.
A work area such as 76, whose function is RAM
It can be realized by hardware such as.

An information storage medium (storage medium from which information can be read by a computer) 150 stores information such as programs and data, and its function is an optical disk (CD, DVD), a magneto-optical disk (MO). ),
It can be realized by hardware such as a magnetic disk, a hard disk, a magnetic tape, or a semiconductor memory (ROM). The processing unit 100 performs various processes of the present invention (the present embodiment) based on the information stored in the information storage medium 150. That is, the information storage medium 150 stores various kinds of information for realizing the means of the present invention (this embodiment) (particularly, the processing unit 100 and blocks included in the storage unit 140).

A part or all of the information stored in the information storage medium 150 is stored in the storage unit 1 when the power of the apparatus is turned on.
Will be forwarded to 40. The information storage medium 150
The information stored in is the program code for performing the processing of the present invention, image information, sound information, display object shape information, table data, list data, player information, and information for instructing the processing of the present invention. , And includes at least one of information for performing processing according to the instruction.

The image generation unit 160 generates various images according to the instruction from the processing unit 100 and the like, and the display unit 162.
Output to the ASI for image generation.
It can be realized by hardware such as C, CPU, or DSP, a given program (image generation program), and image information.

The sound generation section 170 generates various sounds according to an instruction from the processing section 100 and outputs them to the sound output section 172. Its function is that of a sound generation ASIC,
It can be realized by hardware such as a CPU or a DSP, a given program (sound generation program), and sound information (waveform data, etc.).

The communication unit 174 performs various controls for communicating with an external device (for example, a host device or another game device), and its function is the communication ASI.
It can be realized by hardware such as C or CPU or a given program (communication program).

Information for realizing the processing of the present invention (this embodiment) is distributed from the information storage medium of the host device to the information storage medium of the game device via the network and the communication unit 174. Good. The use of the information storage medium of such a host device and the use of the information storage medium of the game device are also included in the scope of the present invention.

Further, a part or all of the functions of the processing unit 100 is controlled by the image generation unit 160, the sound generation unit 170, or the communication unit 1.
You may make it implement | achieve by the function of 74. Alternatively,
The image generation unit 160, the sound generation unit 170, or the communication unit 174.
Some or all of the functions of the above may be realized by the functions of the processing unit 100.

The I / F unit 176 is a memory card (PDA, in a broad sense) according to an instruction from the processing unit 100.
Portable Information Storage Device Including Portable Mini Game Device) 18
It is an interface for exchanging information with 0, and its function is realized by a slot for inserting a memory card and a data write / read controller IC controlled by a command from the CPU. it can. In addition, when information exchange with the memory card 180 is realized using wireless such as infrared rays,
The function of the I / F unit 176 can be realized by hardware such as a semiconductor laser and an infrared sensor.

The processing section 100 includes a game calculation section 110.

Here, the game calculation section 110 receives coins (price), game mode setting processing, game progress processing, selection screen setting processing, and moving objects (fighters,
(Bullet, light source, etc.) position and direction, processing to determine the viewpoint position and line-of-sight direction, processing to reproduce the motion of a moving object, processing to place objects in the object space,
Various game calculation processes such as a hit check process, a process for calculating a game result (score), a process for a plurality of players to play in a common game space, a game over process, and the like, operation information from the operation unit 130, This is performed based on the information from the memory card 180, the game program, and the like. When the present invention is applied to a game other than a fighter game, the moving body may be an airplane other than a fighter, a ship (boat, battleship, submarine, yacht, motor boat, etc.), watercraft, water ski, surfboard. ,car,
Various things such as motorcycles, tanks, robots, spaceships, etc. can be considered.

The game calculation section 110 is a moving body calculation section 11
2, a viewpoint control unit 114, a reflection area setting unit 116, and a reflection calculation processing unit 118 are included.

Here, the moving body computing unit 112 is for computing movement information (position information, direction information, etc.) of a moving body such as a fighter, and for example, operating information input from the operating unit 130 and a given information. Based on the program, it performs processing such as moving a moving object within the object space. That is, a process of moving a moving object in the object space is performed based on operation information from a player (own player, other player) and a command (given movement control algorithm) from a computer.

More specifically, the mobile computing unit 112 is
The position and direction of the moving body is, for example, 1 frame (1/60 second)
The processing required for each is performed. For example, the position of the moving body in the (k-1) frame is PMk-1, the velocity is VMk-1, and the acceleration is AM.
Let k−1 and one frame time be Δt. Then, the position PMk and the speed VMk of the moving body in the k frame can be obtained by the following equations (1) and (2), for example. PMk = PMk-1 + VMk-1 × Δt (1) VMk = VMk-1 + AMk-1 × Δt (2) The viewpoint control unit 114 has information on the position and direction of the moving body obtained by the moving body calculating unit 112. Based on the above, processing for obtaining the viewpoint position, line-of-sight direction, etc. is performed. More specifically, a process of changing the viewpoint position or the line-of-sight direction so as to follow the position or direction of the moving body operated by the player is performed. In this case, it is desirable that the viewpoint position or the line-of-sight direction be made to follow the position or direction of the moving body while maintaining inertia, for example. The image generation unit 150 will generate an image viewed at the viewpoint controlled by the viewpoint control unit 114.

The reflection area setting unit 116 performs processing for setting the reflection area based on the light source position and the viewpoint position. More specifically, for example, a first position that is plane-symmetric with respect to the light source position with respect to the map surface is obtained, and a reflection image object (reflection area in a broad sense) is placed at a second position obtained by perspectively converting the first position into a screen. Processing (setting) is performed.

The reflection calculation processing unit 118, for the dots for which the reflection permission flag is turned on in the reflection area,
Reflection calculation processing for expressing the reflection of light from the light source is performed. More specifically, for example, the reflection calculation process is realized by superimposing a reflection image object on a frame image obtained by perspective-transforming a display object including a map.

The reflection permission flag used by the reflection calculation processing unit 118 is included in the map image information stored in the map image information storage unit 142 of the storage unit 140. That is, the map image information storage unit 142 stores the map image information in which the reflection permission flag indicating whether or not the reflection calculation process is permitted is set for each dot of the map.

The game device of this embodiment is capable of both single-player mode game play in which one player plays and multi-player mode game play in which a plurality of players play.

When a plurality of players play,
The game image and the game sound to be provided to the plurality of players may be generated using one game device, or may be generated using a plurality of game devices connected by a network (transmission line, communication line) or the like. You may.

2. Features of this Embodiment FIGS. 3A, 3B, 4A, and 4B show examples of game images generated by this embodiment.

In the fighter game realized according to the present embodiment, the players are shown in FIGS. 3 (A), 3 (B), 4 (A),
While watching the game image shown in (B), the player controls his fighter to fly in the object space. Then, play the game against other players or fighters operated by the computer.

3 (A), (B), FIG. 4 (A),
In (B), an image from the first person perspective (cockpit image)
However, in the present embodiment, it is also possible to generate an image from a third-person viewpoint (an image in which a fighter operated by itself is displayed).

As shown by E1 in FIG. 3A, according to the present embodiment, the glittering of the sea surface (reflection of light on the sea surface) due to the light from the light source (sun) 18 can be realistically expressed. Also, as shown in FIGS. 3A to 3B, 3B to 4A, and 4A to 4B, the player's viewpoint (fighter) moves forward. If you do,
The sparkle of the sea surface in the reflection area 20 can be expressed without contradiction.

In the fighter game of this embodiment, the player can freely fly the fighter operated by the player in the object space. Therefore, the movement range of the player's viewpoint position is not limited, and the reflection area 20 in which the glitter occurs also moves to an arbitrary place as the viewpoint position moves. In such a game, the above-mentioned second method shown in FIG. 1 (B) cannot realize a consistent expression of the glitter of the sea surface. Further, the processing load becomes very heavy in the first method of FIG. Furthermore, the reflection area 20 is the sea 2.
If the reflection area 20 is on the land 24, the generated game image becomes unnatural if the reflection area 20 is on the land 24.

Therefore, in this embodiment, as shown in FIG. 5, the reflection area 20 (or the reflection area 20 ') is set based on the light source position P0 and the viewpoint position VP. And
The reflection calculation processing for expressing the reflection of the light from the light source is performed on the dots for which the reflection permission flag RF is turned on in the reflection area 20. in this case,
In this embodiment, as shown in FIG. 5, the reflection permission flag RF is set for each dot of the map (land, sea surface) 30. And land (in the broad sense, the first of map 30
In the region (1), the reflection permission flag RF is almost 0 (off), and in the sea (the second region of the map 30 in a broad sense), RF is 1 (on).
Therefore, as shown in FIGS. 3 (A) to 4 (B), the sea 22
In the above, the reflection calculation process is performed and the glitter is expressed, while in the land 24, the reflection calculation process is not performed and the glitter is not expressed. As a result, FIG.
Even when the viewpoint position moves as shown in FIGS. 4A to 4B, a natural image without contradiction can be generated.

As shown by E2 in FIG. 3 (A), in this embodiment, even in the land 24, for example, in the pond 26 or the like, reflection calculation processing is performed to express the glitter. In addition to this, it is desirable to perform the reflection calculation processing on the window glass of the building 28, the steel frame portion of the building, the river, and the like. That is, on land (first area of the map) 24,
You may make it exceptional to provide a dot for turning on the reflection permission flag RF.

Further, in the present embodiment, as shown in FIG. 6, the reflection permission flag RF =
Set to 0 (off). As a result, the land 24 does not have a glitter. On the other hand, at sea 22, RF =
Dots that become 1 (on) are scattered. As a result, the dots that reflect light are interspersed with the dots that do not reflect light. By doing so, it is possible to make the light from the light source appear to be diffusely reflected by the waves on the sea surface without providing the sea surface with undulations as shown in FIG. 1 (A).

That is, in the method of FIG.
1-907 normal vector 911-917 direction change over time, normal vector 911-9
The reflection calculation processing based on 17 and the light source vector 920 is required, and the processing load becomes very heavy. On the contrary,
According to the present embodiment, it is possible to make light appear to be irregularly reflected in a wave just by interspersing dots with RF = 1. That is, a realistic expression is possible with a small processing load.

In this embodiment, the reflection permission flag RF is set for each dot of the map 30 as shown in FIG. 5, but this is set for each dot of the sea surface texture to be mapped to the sea. This can be realized by setting the reflection permission flag RF. More specifically, as shown in FIG. 7, in the palette 34 of the land surface texture 32, the colors C0 to
All the reflection permission flags RF set in C15 are set to 0.
(Turn off. On the other hand, in the palette 38 of the sea surface texture 36, for example, RF is set to 1 (on) only for the colors C16 to C19, and RF is set to the other colors C20 to C31.
To 0. Then, the land 24 of the frame image 40 is drawn by texture mapping using the land texture 32 and the palette 34. On the other hand, the sea 22 is drawn by texture mapping using the sea surface texture 36 and the palette 38.

In this way, as shown in FIG. 6, in the land 24, RF becomes almost zero over the entire surface. In the sea 22, RF = 1 dots are scattered. This is because in the sea 22, the dots drawn with the colors C16 to C19 in FIG. 7 have RF = 1, and the dots drawn with the colors C20 to C31 have RF = 0.

Further, in this embodiment, when the frame image obtained by perspectively transforming the display object including the map on the screen is written in the frame buffer, the reflection permission flag RF is applied to each dot (pixel) of the frame buffer. Is written, and the reflection calculation process is performed based on the written RF. By doing so, RF = 1 is written in the frame buffer and reflection calculation processing is performed, even if the dots are at the same location, depending on the viewpoint position or the positional relationship between the line-of-sight direction and the map.
F = 1 is not written and the reflection calculation process is not performed. As a result, FIG. 3 (A) to FIG. 4 (B)
As indicated by E3, E4, E5, and E6, the dots at the same place start blinking or do not blink as the viewpoint position moves, and it is possible to express a more realistic glitter.

That is, in FIG. 8A, the dots D0, D
The image information of 2, D3, and D4 is written in the frame buffer 144 of FIG. 2 in the perspective conversion to the screen 42. Therefore, the RF included in the image information of these dots
= 1 is also written in the frame buffer 144, and the dot D
0, D2, D3, D4 will start to shimmer on the screen.
On the other hand, the image information of the dot D1 is deformed by the perspective transformation and is not written in the frame buffer 144. Therefore, RF = 1 included in the image information of the dot D1 is not written in the frame buffer 144, and the dot D1 does not flicker on the screen.

On the other hand, in FIG. 8B, the dots D1 and D3 are
Image information is written in the frame buffer 144, and
Since F = 1 is also written in the frame buffer 144,
D1 and D3 start to shimmer on the screen. On the other hand, the image information of the dots D0, D2, and D4 is deformed by the perspective transformation and is not written in the frame buffer 144, and RF = 1 is not written in the frame buffer 144 either. Therefore, the dots D0, D2, and D4 will not flicker on the screen.

As described above, in the present embodiment, the dots D0, D2, and D4, which were sparkling in FIG. 8A, are shown in FIG. 8B.
Then it won't give up. In addition, the dot D1 which was not glittered in FIG. 8A becomes to be glittered in FIG. 8B. That is, when the positional relationship between the viewpoint position and the line-of-sight direction and the map changes (when the degree of scaling by perspective transformation changes), the image information of dots at the same location (reflection permission flag) is changed due to the deformation of the image information by perspective transformation. It may or may not be written to the frame buffer. This will cause the dots at the same location to blink or not to blink. Therefore, it is possible to realistically express the sparkle of the sea surface without performing the heavy-duty reflection calculation processing as shown in FIG.

In particular, as shown in FIG. 3, the image effect in which the dots at the same place glitter or do not blink in this way is shown in FIG.
As shown by E3 in (A), it becomes noticeable in dots located far away from the viewpoint.

Further, in the present embodiment, the width of the reflection area becomes narrower as the incident angle of the light from the light source becomes larger,
The brightness of the reflection area is increased.

That is, as shown in FIG. 9A, when the incident angle θ of the light from the light source is small, the width of the reflection area 20 is widened and the brightness in the reflection area 20 (corresponding to the brightness of the reflection light) ) Lower. On the other hand, as shown in FIG. 9B, when the incident angle θ of the light from the light source is large, the width of the reflection area 20 is narrowed and the brightness in the reflection area 20 is increased.

By doing so, when the position of the light source (the sun) is lowered and comes near the horizon, it becomes possible to realistically express how the area where the light shimmers becomes thin vertically while shining strongly. .

Such a change in the width or brightness of the glittering area can be realized by performing a light reflection calculation based on the light source vector and the normal vector by the first method shown in FIG. 1A, for example. However, with this first approach,
The processing load becomes very heavy.

In the present embodiment, the set reflection area 20 is set.
The reflection calculation processing is used to express the sparkle of the sea surface. Therefore, even if the method as shown in FIG. 1A is not adopted, the phenomenon in which the region where the light shines becomes thin vertically and strongly shines can be realistically expressed only by controlling the width and the brightness of the reflection region 20. .

The width and brightness of the reflection area 20 are controlled by
It is not always necessary to control by using the incident angle θ of light itself, and the control may be performed using a parameter equivalent to the incident angle θ of light (for example, an altitude difference coefficient α described later).

Further, in this embodiment, when the reflection area goes out of the screen, the reflection calculation processing in the reflection area is omitted.

For example, as shown in FIG. 10A, when the reflection area 20 goes out of the screen (display screen) due to the line-of-sight direction facing upward, the reflection calculation processing in the reflection area 20 is performed. Omit it. By doing so, it is possible to prevent unnecessary processing from being performed, and to speed up the processing.

In this embodiment, the longer the distance between the viewpoint and the map, the lower the brightness of the reflection area.

For example, as shown in FIG. 10B, when the viewpoint position VP is far away from the map 30, the brightness of the reflection area 20 is lowered so that the reflection area 20 gradually disappears on the screen. To That is, in this type of game device,
A display object far away from the viewpoint position VP is gradually erased from the screen by using depth cueing processing or the like. For example, in FIG. 10B, when the distance between the viewpoint position VP and the map 30 is far, the land 24
Gradually disappears on the screen due to the depth cueing process. In such a case, if the brightness of the reflection area 20 is high,
The reflective area 20 is conspicuous on the screen (the reflective area 20
The image becomes unnatural.

According to the present embodiment, as the distance between the viewpoint position VP and the map 30 increases and the display object such as the land 24 gradually disappears on the screen, the brightness of the reflection area 20 also decreases and the brightness on the screen decreases. It gradually disappears (it gradually becomes thinner). As a result, it is possible to prevent a situation in which the reflection area 20 is conspicuous and an unnatural image is generated.

The control for lowering the brightness of the reflection area 20 does not necessarily have to be performed by using the distance itself between the viewpoint position VP and the map, and a parameter equivalent to this distance (for example, an altitude difference coefficient α described later) is used. ) May be used for control.

In the present embodiment, more specifically, the reflection calculation processing is realized as follows.

That is, in FIG. 11, first, with respect to the plane (horizontal plane) of the map 30, the position P0 of the light source and the position P which is plane-symmetrical.
1 (first position) is obtained, and this position P1 is set on the screen 4
A position P2 (second position) perspectively transformed into 2 is obtained. Then, the reflection image object 50 is set at this position P2 (the reflection image object 50 is arranged so that the position P2 and the center point (representative point) of the reflection image object 50 coincide).

Next, as shown in FIG. 12A, a reflection image object 50 is overwritten on the frame image 40 obtained by perspectively transforming a display object such as a map on the screen 42. By doing so, the reflection calculation process for expressing the reflection of the light from the light source can be easily realized.

As shown in FIG. 12B, when the viewpoint (frame image, view image) is rotated around the Z axis (coordinate axis in the depth direction), the reflection image object 50 is displayed.
Also, it is desirable to rotate about the Z axis and then overwrite the frame image 40.

Further, although not particularly limited to the present invention, in the present embodiment, even if the viewpoint position VP moves, VP
The relative positional relationship between the light source position P0 and the light source position P0 does not change. By doing so, it is possible to make the light source position P0 appear to be at infinity. It is also possible to change the light source position P0 with the lapse of time. In this way, it is possible to express that the sun rising from the east moves over the sky over time and sets in the west.

The following method can be considered as another method for realizing the reflection calculation processing. That is, in this method, first, the position P1 in FIG.
1. A position P2 ′ which is an intersection of the line connecting the viewpoint position VP and the map 30 is obtained. Then, the three-dimensional reflection image object 50 'is set (arranged) at this position P2'. However, in this method, a process of obtaining a position P2 ′ which is an intersection of the line connecting P1 and VP and the map 30, a process of changing the size H ′ of the reflection image object 50 ′ in the depth direction according to the line-of-sight direction, etc. Will be required. Therefore, the processing load becomes heavy.

On the other hand, in the method of setting the two-dimensional reflection image object 50 at the position P2, the position P2 can be obtained only by perspectively converting the position P1 onto the screen 42. Further, with this method, the size H of the reflection image object 50 in the depth direction can be set to a fixed value that does not depend on the line-of-sight direction. That is, H is a function of only the screen distance SD (angle of view) (for example, H = 2 × SD × ta
nβ). Therefore, compared with the method of setting the three-dimensional reflection image object 50 at the position P2 ′,
The processing load can be reduced.

Note that when the reflection image object 50 is overwritten on the frame image 40 as shown in FIGS. 12 (A) and 12 (B),
This can be realized by a semitransparent addition process of the frame image 40 and the reflection image object 50.

That is, as shown in FIG. 12C, the size of the reflection image object 50 in the depth direction (the length of the long axis) is set.
Is H and the size in the horizontal direction (the length of the short axis) is W, which is an elliptical object. In this case, this elliptical object is represented by combining a plurality of triangular polygons. Further, the brightness of the center point PC of the reflection image object 50 is set to a given value IC (for example, IC = 1.0), and the brightness of the contour points PL0 to PL11 is set to 0.0. Then, the brightness is gradually lowered (gradation is applied to the brightness) from the center point PC toward the contour points PL0 to PL11. Further, the color of the reflected image object 50 is set to the color of reflected light (for example, yellowish white).

The frame image 40 and the reflection image object 5
The translucent addition process with 0 can be expressed by the following equation, for example. PR = FR + I × RR (3) PG = FG + I × RG (4) PB = FB + I × RB (5) Here, FR, FG, and FB are R, G, and B components of the color information of the frame image 40, and RR. , RG, RB are R, G, B components of the color information of the reflection image object 50, and P
R, PG, and PB are R, G, and B components of the color information of the output image obtained by the semitransparent addition process. Further, I is the brightness set in the reflection image object 50.

For example, at the contour points PL0 to PL11 of the reflection image object 50, the brightness I = 0.0 as shown in FIG. 12C, so that PR = FR, PG = FG, PB.
= FB. That is, at the contour points PL0 to PL11, the frame image 40 becomes the output image as it is, and the contour points PL0 to PL0.
With PL11, no glitter occurs. At the center point PC of the reflection image object 50, the brightness I is, for example, IC =
Since it becomes 1.0, PR = FR + RR, PG = FG + R
G and PB = FB + RB. That is, at the center point PC, the frame image and the image of the reflection image object are semi-transparently added to form an output image, and the center point PC has the strongest glitter.

In the present embodiment, the width and brightness of the reflection image object are controlled according to the altitude difference between the viewpoint position VP and the position P1.

That is, as shown in FIG. 13A, the viewpoint position VP
And a position P1 (a first position that is plane-symmetric with respect to the light source position P0 with respect to the surface of the map 30), a coefficient α representing a height difference
Is large, the width (size W in the horizontal direction) of the reflection image object (reflection area in a broad sense) 50 is increased, and the luminance of the reflection image object 50 (luminance I at the center point) is increased.
Lower C). On the other hand, as shown in FIG. 13B, when the altitude difference coefficient α between VP and P1 is small, the width (size W in the horizontal direction) of the reflection image object 50 is reduced and the brightness of the reflection image object 50 is reduced. (Luminance I at the center point
Increase C).

As shown in FIG. 13A, when the incident angle θ is small, the distance P between the light source position P0 and the map 30 and the position P.
The distance between 1 and the map 30 becomes long, and the altitude difference coefficient α becomes large. Further, as shown in FIG. 13B, when the incident angle θ is large, the distance between P0 and the map 30 and the distance between P1 and the map 30 are short, and α is small. Therefore, a small incident angle θ is almost equivalent to a large α, and a large incident angle θ is substantially equivalent to a small α.

Therefore, in this embodiment, the width and brightness of the reflection image object 50 are controlled by using the altitude difference coefficient α without directly obtaining the incident angle θ. By doing so, it becomes possible to realize the control of the width and brightness of the reflection area according to the incident angle θ of light as shown in FIGS. 9A and 9B without directly obtaining the incident angle θ. . Therefore, the process of obtaining the incident angle θ can be omitted, and the processing load can be reduced.

If the brightness of the reflection image object 50 is controlled using the altitude difference coefficient α, as shown in FIG. 14, the brightness of the reflection image object 50 when the distance between the viewpoint position VP and the map 30 is long. The process of lowering the value can also be realized by using the altitude difference coefficient α. The increase in the altitude difference coefficient α is almost equivalent to the increase in the distance between the VP and the map 30.

That is, in FIGS. 9A and 9B, the brightness of the reflection area is controlled based on the incident angle θ, and in FIG. 10B, based on the distance between the viewpoint position VP and the map 30, It controls the brightness of the reflective area. Therefore, there are two parameters for controlling the brightness of the reflection area, which complicates the processing.

On the other hand, if the altitude difference coefficient α is used,
In both cases of FIGS. 13A and 13B and FIG. 14, the same altitude difference coefficient α can be used to control the brightness of the reflection image object 50. Therefore, as shown in FIG.
10B, the processing load is reduced as compared with the case where two parameters (incident angle θ, viewpoint position VP, distance between maps 30) are used to control the brightness of the reflection area as shown in FIG. 10B. Can be realized.

When controlling the width of the reflection image object 50 based on the altitude difference coefficient α, it is desirable to set an upper limit value for α (for example, α should not be larger than 1.0).

Further, in the present embodiment, the contour and brightness distribution of the reflection image object fluctuate with the passage of time.

That is, as shown in FIG. 15A, fluctuations that change with time are added to the center point PC and the contour points PL0 to PL11 of the reflection image object 50 whose width and brightness are determined. Then, in this way, the center point PC and the contour point PL
The reflected image object 50 in which fluctuation is added to 0 to PL11 is overwritten in the frame buffer 144 of FIG.

The fluctuation which changes with the passage of time is taken as the contour point P.
By adding to L0 to PL11, the contour of the reflected image object 50 fluctuates as shown in FIG. This makes it possible to prevent the boundary of the reflection image object 50 from becoming conspicuous. That is, FIG.
In the game images of (A), (B), FIG. 4 (A), and (B), it is possible to blur the outline of the reflection area 20, and prevent a situation in which the player feels unnatural in the image. become.

Further, by adding a fluctuation that changes with the passage of time to the center point PC, it is possible to change the luminance distribution of the reflection image object 50. This is because the position of the center point PC having the highest brightness changes with the passage of time. By changing the brightness distribution of the reflection image object 50 in this way, it becomes possible to more realistically represent the sparkle of the sea surface.

That is, in the method of FIGS. 8A and 8B, when the viewpoint position VP is moving, the dots at the same location may blink or may not blink.
It enables a realistic expression of the sparkle of the sea surface. However, in the case where the viewpoint position VP is stationary, FIG.
The methods of (A) and (B) cannot achieve a realistic expression of glitter.

On the other hand, as shown in FIGS. 15A and 15B, if the central point PC of the reflection image object 50 is fluctuated and the luminance distribution is changed over time, the viewpoint position VP is stationary. Even if you are doing it, the sea surface will appear to shimmer, and a realistic expression of the sea surface sparkle becomes possible.

3. Processing of this Embodiment Next, a detailed processing example of this embodiment will be described with reference to FIGS.
This will be described with reference to the flowchart of FIG.

First, a frame image is generated based on the map image information stored in the map image information storage unit (texture storage unit) 142 in FIG.
It writes in 44 (step S1). At this time, in the present embodiment, the reflection permission flag RF is also written in the frame buffer 144. In this way, as described with reference to FIGS. 8A and 8B, it is possible to realize a realistic expression of the glitter using the deformation of the image information by the perspective transformation.

Next, as shown in FIG. 11, the map 3
A position P1 that is plane-symmetric with respect to the light source position P0 with respect to the 0 surface is obtained (step S2). Then, the size H = 2 × SD × tan β of the reflection image object in the depth direction is obtained based on the screen distance SD (angle of view) (step S
3). Note that β is a constant and is, for example, 10 degrees.

Next, as described with reference to FIGS. 13A and 13B, the horizontal size W = H of the reflection image object 50 is calculated based on the size H in the depth direction and the altitude difference coefficient α.
Xα is obtained (step S4). When obtaining the size W in the horizontal direction, a limit value is set for the altitude difference coefficient α, and α has a value of 0.3 to 1.0 (α = 1.
In the case of 0, the reflection image object 50 becomes a perfect circle).

Next, as described with reference to FIG. 11, the position P1
A position P2 is obtained by perspective-transforming the image on the screen 42 (step S5).

Next, the position P2 and the reflection image object 50
Whether the reflection image object 50 has gone out of the screen based on the size (H, or H and W) of FIG.
(See (A)) is determined (step S6 in FIG. 17). If it goes out of the screen, the following step S7
The process of S13 (reflection calculation process) is omitted. On the other hand, when it is in the screen, the brightness IC of the center point PC of the reflection image object 50 is changed based on the altitude difference coefficient α as described with reference to FIGS. 13 (A), 13 (B) and 14. Step S7). That is, when the altitude difference coefficient α is small, the brightness IC is increased, and when α is large, the brightness IC is decreased.

Next, as described with reference to FIGS. 12A and 12B, the reflection image object 50 is rotated in accordance with the rotation of the Z axis of the viewpoint (step S8). And in FIG.
As described in (A) and (B), the reflection image object 5
Fluctuation is added to the contour points PL0 to PL11 of 0 and the center point PC (step S9).

Next, it is judged whether or not the reflection permission flag RF of the dot to be processed is turned on (step S10). If RF is off, the process proceeds to the next dot (step S13). That is, FIG.
As shown in (1), in most cases, the reflection permission flag RF is off (RF = 0) on the land, so the process proceeds to the next dot.

When it is determined that RF is ON (RF = 1), reflection calculation processing (processing of overwriting the reflection image object on the frame image) is performed on the dot (step S11). That is, as described with reference to FIG. 5, dots with RF = 1 are scattered in the sea, and reflection calculation processing is performed on these dots.
Then, it is determined whether or not the processing for all the dots of the reflection image object 50 is completed (step S12),
If not completed, the process proceeds to the next dot (step S13).

4. Hardware Configuration Next, an example of a hardware configuration capable of realizing the present embodiment will be described with reference to FIG. In the apparatus shown in the figure, a CPU 1000, a ROM 1002, a RAM 100
4, information storage medium 1006, sound generation IC 1008, image generation IC 1010, I / O ports 1012, 1014
Are connected by a system bus 1016 so that data can be transmitted and received between them. The image generation IC 1010
A display 1018 is connected to the sound generation IC 10
A speaker 1020 is connected to 08, and I / O port 1
A control device 1022 is connected to 012 and I / O
A communication device 1024 is connected to the O port 1014.

The information storage medium 1006 mainly stores programs, image data for expressing display objects, sound data, and the like. For example, in a home-use game machine, a CD-R is used as an information storage medium for storing game programs and the like.
OM, game cassette, DVD, etc. are used. A memory such as a ROM is used in the arcade game machine, and in this case, the information storage medium 1006 becomes the ROM 1002.

The control device 1022 corresponds to a game controller, an operation panel, etc., and is a device for inputting the result of the judgment made by the player according to the progress of the game to the main body of the device.

A program stored in the information storage medium 1006, a system program stored in the ROM 1002 (initialization information of the apparatus main body, etc.), the control apparatus 102.
CPU 1000 in accordance with signals input by
Controls the entire device and processes various data. RAM10
Reference numeral 04 denotes a storage unit used as a work area of the CPU 1000, which is an information storage medium 1006 or ROM 10.
The given contents of 02, the calculation result of the CPU 1000, etc. are stored. A data structure having a logical configuration for realizing the present embodiment is constructed on this RAM or information storage medium.

Further, this type of device has a sound generation IC 100.
8 and an image generation IC 1010 are provided so that a game sound and a game image can be appropriately output.
The sound generation IC 1008 is an information storage medium 1006 or ROM 1.
It is an integrated circuit that generates game sounds such as sound effects and background music based on the information stored in 002, and the generated game sounds are output by the speaker 1020. Further, the image generation IC 1010 includes a RAM 1004,
It is an integrated circuit that generates pixel information to be output to the display 1018 based on image information sent from the ROM 1002, the information storage medium 1006, or the like. As the display 1018, a so-called head mounted display (HMD) can be used.

The communication device 1024 exchanges various information used inside the game device with the outside, and is connected to another game device to send and receive given information according to the game program. It is used to send and receive information such as game programs via a communication line.

The various processes described with reference to FIGS. 1 to 17 are the information storage medium 1006 storing information such as programs and data, the CPU 1000 operating based on the information from the information storage medium 1006, and the image generation IC 10.
10 or a sound generation IC 1008 or the like. The processing performed by the image generation IC 1010, the sound generation IC 1008, etc. is performed by the CPU 1000 or a general-purpose DS.
You may perform by software by P etc.

FIG. 19A shows an example in which this embodiment is applied to an arcade game machine. The player enjoys the game by operating the lever 1102, the buttons 1104, etc. while watching the game image displayed on the display 1100. A CPU, an image generation IC, a sound generation IC, etc. are mounted on a system board (circuit board) 1106 built in the device. And (1) means for storing map image information in which a reflection permission flag indicating whether or not to permit the reflection calculation processing for expressing the reflection of light from the light source is set for each dot of the map , (2) means for setting the reflection area based on the light source position and the viewpoint position, (3) means for performing reflection calculation processing on dots for which the reflection permission flag is turned on in the reflection area , (4) A second position obtained by perspectively transforming the first position on the screen by obtaining a first position symmetrical with respect to the light source position with respect to the map surface.
Means for setting the reflection image object at the position of
(5) Perform reflection calculation processing to express reflection of light from a light source by overwriting a reflection image object on a frame image obtained by perspectively transforming a display object including a map on a screen. Information for realizing the means for achieving the above is stored in the semiconductor memory 1108 which is an information storage medium on the system board 1106. Less than,
This information is called stored information.

FIG. 19B shows an example in which this embodiment is applied to a home-use game machine. The player looks at the game image displayed on the display 1200,
Enjoy the game by operating the game controllers 1202 and 1204. In this case, the stored information is stored in a CD-ROM 1206, memory cards 1208, 1209, etc., which are removable information storage media in the main unit.

FIG. 19C shows a host device 1300,
A terminal 1304-1 connected to the host device 1300 via a communication line (small-scale network such as LAN or wide area network such as the Internet) 1302.
1304-n is applied to the system. In this case, the stored information is stored in an information storage medium 1306 such as a magnetic disk device, a magnetic tape device, a semiconductor memory or the like which can be controlled by the host device 1300. Terminals 1304-1 to 1304-n are CPs
In the case of having U, an image generation IC, and a sound processing IC and capable of standalone generation of a game image and a game sound, the host device 1300 provides a game program and the like for generating the game image and the game sound. Terminal 1304-1
~ 1304-n. On the other hand, when it cannot be generated standalone, the host device 1300 generates a game image and a game sound, and these are generated by the terminals 1304-1 to 130.
It will be transmitted to 4-n and output at the terminal.

In the case of the configuration shown in FIG. 19C, the processing of the present invention is distributed to the host device and the terminal (or the host device, the server and the terminal when the server is provided). You may Further, the above stored information for realizing the present invention is distributed to the information storage medium of the host device and the information storage medium of the terminal (or the information storage medium of the host device, the information storage medium of the server and the information storage medium of the terminal). You may make it store it.

Further, the terminal connected to the communication line may be a home-use game machine or an arcade game machine. When the arcade game device is connected to a communication line, portable information storage that can exchange information with the arcade game device and also exchange information with the home game device. Device (memory card,
It is desirable to use a PDA, a portable game device).

The present invention is not limited to that described in the above embodiment, and various modifications can be made.

For example, the method of setting the reflection permission flag is not limited to that described with reference to FIG.

The reflection area may be set in the object space (for example, the reflection image object 5 in FIG. 11).
0 '), may be set on the screen (reflection image object 50).

Further, the reflection calculation process is performed by the process shown in FIG.
The calculation processing is not limited to the semi-transparent addition processing as described in (B) and (C), and may be at least arithmetic processing capable of expressing reflection of light from the light source.

Further, in the present invention, as described with reference to FIGS. 8A and 8B, it is particularly desirable to write the reflection permission flag for each dot in the frame buffer when the frame image is written in the frame buffer. However, the present invention is not limited to this.

Further, in the invention in which the reflection calculation processing is realized by setting the reflection image object at the second position and overwriting the reflection image object on the frame image, the reflection permission flag is set to each dot of the map. Is particularly desirable, but it is possible not to use such a reflection permission flag.

Further, the present invention is applicable to various games (plane games other than fighters, spaceship games, other than fighter games, etc.).
It can be applied to competitive games, fighting games, robot fighting games, sports games, shooting games, role-playing games, etc.).

Further, the present invention is applicable to various games such as an arcade game machine, a home game machine, a large attraction machine in which a large number of players participate, a simulator, a multimedia terminal, an image generating apparatus, and a system board for generating a game image. Applicable to devices.

[Brief description of drawings]

1A and 1B are diagrams for explaining first and second methods of expressing sparkle on a water surface.

FIG. 2 is an example of a block diagram of a game device according to the present embodiment.

FIG. 3A and FIG. 3B are diagrams showing an example of a game image generated by the present embodiment.

FIG. 4A and FIG. 4B are also diagrams showing an example of a game image generated by this embodiment.

FIG. 5 is a diagram for explaining a method of performing a reflection calculation process using a reflection permission flag set for each dot of the map.

FIG. 6 is a diagram for explaining a method of setting RF to 0 almost entirely on land and interspersing dots with RF = 1 on the sea.

FIG. 7 is a diagram for explaining a specific example of a method of setting a reflection permission flag for each dot of a map.

8A and 8B are diagrams for explaining a method of writing a reflection permission flag for each dot in the frame buffer when writing a frame image in the frame buffer.

9A and 9B are diagrams for explaining a method of controlling the width and brightness of a reflective region according to the incident angle of light from a light source.

10A and 10B are a method for omitting reflection calculation processing when a reflection area appears outside the screen,
To explain the method of lowering the brightness of the reflection area when the distance between the viewpoint position and the map is far

FIG. 11 is a diagram for explaining a method of realizing reflection calculation processing by overwriting a reflection image object set at a position P2 on the screen 42 on a frame image.

FIGS. 12A, 12B, and 12C are diagrams for explaining a method of realizing reflection calculation processing by semitransparent addition processing.

13A and 13B are diagrams for explaining a method of controlling the width and brightness of a reflected image object based on the altitude difference coefficient α.

FIG. 14 is a diagram illustrating a method of controlling the brightness of a reflected image object based on an altitude difference coefficient α.

15A and 15B are diagrams for explaining a method of adding fluctuations that change with time to a center point and a contour point of a reflection image object.

FIG. 16 is an example of a flowchart showing a detailed processing example of the present embodiment.

FIG. 17 is an example of a flowchart showing a detailed processing example of the present embodiment.

FIG. 18 is a diagram showing an example of a hardware configuration capable of realizing the present embodiment.

19 (A), (B), and (C) are diagrams showing examples of various types of devices to which the present embodiment is applied.

[Explanation of symbols]

18 Light source (sun) 20 Reflection area 22 sea 24 land 26 ponds 28 building 30 maps 32 land texture 34 pallets 36 sea surface texture 38 pallets 40 frame images 42 screen 50, 50 'reflection image object 100 processing unit 110 Game calculation unit 112 Mobile unit 114 viewpoint control unit 116 Reflection Area Setting Section 118 Reflection calculation processing unit 130 Operation unit 140 storage 142 Map image information storage unit 144 frame buffer 150 information storage medium 160 image generator 162 display 170 sound generator 172 sound output section 174 Communication unit 176 I / F section 180 memory card (or PDA)

Claims (10)

[Claims] 1. A game device for generating an image, comprising means for storing map image information, a first position symmetrical with respect to a light source position with respect to a map surface, and the first position. Means for setting a reflection image object at a second position perspectively transformed on the screen, and the reflection image object is overwritten on a frame image obtained by perspectively transforming a display object including a map on the screen. Thus, a game device comprising: means for performing reflection calculation processing for expressing reflection of light from a light source. 2. The game device according to claim 1, wherein a reflection permission flag indicating whether or not to permit the reflection calculation process is set for each dot of the map. 3. The reflection enable flag according to claim 2, wherein when a frame image obtained by perspectively transforming a display object including a map on a screen is written to a frame buffer, the reflection permission flag is written to each dot of the frame buffer. In addition, the game device is characterized in that the reflection calculation processing is performed based on the reflection permission flag written in the frame buffer. 4. The method according to claim 1, wherein at least one of the width of the reflection image object and the brightness of the reflection image object is controlled according to an altitude difference between a viewpoint position and the first position. A game device characterized in that 5. The game device according to claim 1, wherein at least one of a contour and a luminance distribution of the reflection image object is shaken over time. 6. A computer-readable information storage medium for generating an image, a means for storing map image information, and a first symmetric plane with respect to the light source position with respect to the map plane. Means for determining the position of the reflection image object and setting a reflection image object at a second position obtained by perspective-transforming the first position on the screen; and perspective-transforming the reflection image object to a screen including a display object including a map. An information storage medium including a program for causing a computer to function as a means for performing reflection calculation processing for expressing reflection of light from a light source by overwriting on a frame image obtained by . 7. The information storage medium according to claim 6, wherein a reflection permission flag indicating whether or not to permit the reflection calculation process is set for each dot of the map. 8. The reflection permission flag according to claim 7, wherein when a frame image obtained by perspectively transforming a display object including a map on a screen is written in a frame buffer, the reflection permission flag is written in each dot of the frame buffer. The information storage medium is characterized in that the reflection calculation processing is performed based on the reflection permission flag written in the frame buffer. 9. The at least one of the width of the reflection image object and the luminance of the reflection image object according to claim 6, wherein the width of the reflection image object is controlled according to the altitude difference between the viewpoint position and the first position. An information storage medium characterized by the following. 10. The information storage medium according to claim 6, wherein at least one of the contour and the luminance distribution of the reflection image object is caused to fluctuate with the passage of time.