JP3538394B2 - GAME SYSTEM, PROGRAM, AND INFORMATION STORAGE MEDIUM - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a game system,
The present invention relates to a program and an information storage medium.

[0002]

2. Description of the Related Art Conventionally, there is known a game system that generates an image that can be seen from a given viewpoint in an object space that is a virtual three-dimensional space. It is very popular as something that can be done. Taking a game system that can enjoy a role-playing game (RPG) as an example, a player operates a character (object) that is his / her own character to move it on a map in the object space and play against an enemy character. Or interact with other characters,
Enjoy games by visiting various towns.

In such a game system, an object representing a character or the like is composed of a plurality of polygons and free-form surfaces (primitive surfaces in a broad sense). Then, an object (model) constituted by the polygon is arranged in the object space, and geometry processing (three-dimensional calculation) is performed to generate an image that can be seen from a given viewpoint in the object space. As a result, it is possible to generate an image that is realistic and close to a real image as if it were a real-world landscape.

On the other hand, in the fields of anime and manga, people are not attracted by real images such as live-action images, but are attracted by cel image-like images unique to anime.

Accordingly, game images generated by conventional game systems can appeal to the feelings of those who like reality, but cannot yet appeal to the feelings of those who like anime and manga. is there.

In order to solve such a problem, the present applicant has developed a game system capable of generating a cell-style image in real time. In order to generate such a cell-like image, a process of drawing an edge line of an object such as a character (a process of enhancing the outline) is required.

However, it has been found that such object outline drawing processing has the following problems.

That is, assume that a contour line having a thickness of 1 pixel is drawn on the outer periphery of the object. In such a case,
When the distance between the viewpoint and the object is short (when the size of the object with respect to the pixel on the screen is large), the problem does not occur so much. However, when the distance between the viewpoint and the object is long (when the size of the object relative to the pixel on the screen is small)
In this case, the relative thickness of the contour line with respect to the size of the object becomes thicker than necessary, and an unnatural image is generated.

The present invention has been made in view of the above problems, and its object is to provide a game system capable of efficiently generating a higher quality contour image,
It is to provide a program and an information storage medium.

[0010]

In order to solve the above-mentioned problems, the present invention provides a game system for generating an image, comprising: a means for drawing an image of an object outline; and an image of an object outline. And means for changing the distance according to the distance from the viewpoint, and means for generating an image at a given viewpoint in the object space. The information storage medium according to the present invention is an information storage medium that can be used by a computer, and includes a program for executing the above means. The program according to the present invention is a program (including a program embodied in a carrier wave) that can be used by a computer, and includes a processing routine for executing the above means.

According to the present invention, an outline image (color, translucency (darkness), brightness, hue,
Brightness, saturation, etc.) change. Therefore, the contour image can be set to an optimum image corresponding to the distance from the viewpoint, and a high-quality contour image can be generated.

As the distance from the viewpoint, a depth distance, a linear distance between the viewpoint and the object, or various parameters equivalent to these distances can be considered.

The object to be drawn with the contour line may be the entire model object or a part object (sub-object) constituting the model object.

As a technique for drawing the outline of an object, a technique of shifting texture coordinates by a texel interpolation method is particularly desirable, but is not limited to this.

In addition, the game system, information storage medium and program according to the present invention have a greater distance from the viewpoint.
It is characterized in that the color of the contour line of the object approaches a given second color. In this way, when the distance from the viewpoint is long, the color of the contour line of the object can be brought closer to the inconspicuous second color.

Also, the game system, information storage medium and program according to the present invention are such that the distance from the viewpoint is near the distance when the viewpoint follows the object while keeping the distance to the object substantially constant. Is characterized in that the color of the outline of the object is kept substantially constant. In this way, in the mode in which the viewpoint follows the object while maintaining a substantially constant distance, the color of the outline of the object hardly changes, and a more natural image can be generated.

In the game system, information storage medium, and program according to the present invention, the color of the outline of the object is changed to the second color when the distance from the viewpoint is longer than a given threshold value. It is characterized by being set. In this way, when the distance from the viewpoint is greater than a given threshold, the color of the contour line is set to the second color,
The problem that the relative thickness of the contour line becomes conspicuous can be reliably prevented.

In addition, the game system, information storage medium and program according to the present invention have a greater distance from the viewpoint.
The outline image of the object is more transparent. In this way, when the distance from the viewpoint is long, it is possible to make the contour image of the object lighter in darkness so that the contour image is less noticeable.

In addition, the game system, information storage medium and program according to the present invention are such that the distance from the viewpoint is near the distance when the viewpoint follows the object while keeping the distance to the object substantially constant. Is characterized in that the translucency of the outline of the object is kept substantially constant. In this way, when the viewpoint follows the object while maintaining a substantially constant distance, the translucency (darkness) of the outline of the object hardly changes, so that a more natural image can be generated. Become.

The game system, information storage medium, and program according to the present invention are characterized in that the image of the outline of the object becomes almost invisible when the distance from the viewpoint is longer than a given threshold value. And In this way, when the distance from the viewpoint is longer than a given threshold value, the contour image becomes completely transparent, and the relative thickness of the contour line becomes conspicuous. Can be surely prevented.

According to another aspect of the present invention, there is provided a game system for generating an image, the means for drawing an image of an object outline, and the image of the object outline changed in accordance with the size of the object after perspective transformation. And means for generating an image at a given viewpoint in the object space. The information storage medium according to the present invention is an information storage medium that can be used by a computer, and includes a program for executing the above means. The program according to the present invention is a program (including a program embodied in a carrier wave) that can be used by a computer, and includes a processing routine for executing the above means.

According to the present invention, the contour image (color, translucency (darkness), luminance, hue, brightness, etc.) according to the size of the object after perspective transformation (size relative to the pixel).
Or, saturation etc.) changes. Therefore, the image of the outline is
It becomes possible to set an optimal image according to the size of the object, and a high-quality contour image can be generated.

As the size of the object, the total number of pixels of the object (the number of vertical pixels × the number of horizontal pixels), the number of vertical pixels, the number of horizontal pixels, or various parameters equivalent to the number of pixels. Can think.

Also, a virtual object is generated that contains an image of the object after perspective transformation and changes its size according to the size of the object after perspective transformation. The size of the virtual object is defined as the size of the object. It may be set.

The game system, information storage medium, and program according to the present invention are characterized in that the color of the outline of an object approaches a given second color as the size of the object after perspective transformation is smaller. To do. In this way, when the size of the object on the screen is small, the color of the contour line of the object can be brought closer to the inconspicuous second color.

In addition, the game system, information storage medium and program according to the present invention provide the object size when the viewpoint follows the object while the size of the object after the perspective transformation keeps the distance to the object substantially constant. When it is near the size, the color of the outline of the object is kept substantially constant. In this way, in the mode in which the viewpoint follows the object while maintaining a substantially constant distance, the color of the outline of the object hardly changes, and a more natural image can be generated.

In the game system, information storage medium, and program according to the present invention, when the size of the object after perspective transformation is smaller than a given threshold, the color of the outline of the object is It is characterized by being set to 2 colors. In this way, when the size of the object after perspective transformation becomes smaller than a given threshold value, the color of the contour line is set to the second color, and the relative thickness of the contour line is set. This makes it possible to reliably prevent problems that are conspicuous.

The game system, information storage medium and program according to the present invention are characterized in that the outline image of an object becomes more transparent as the size of the object after perspective transformation is smaller. In this way, when the size of the object on the screen is small, it is possible to make the contour image of the object lighter, thereby making the contour image less noticeable.

In addition, the game system, information storage medium and program according to the present invention provide the object size when the viewpoint follows the object while the distance of the object after the perspective transformation is kept substantially constant. When it is near the size, the translucency of the outline of the object is kept substantially constant. In this way, when the viewpoint follows the object while maintaining a substantially constant distance, the translucency (darkness) of the outline of the object hardly changes,
A more natural image can be generated.

In the game system, information storage medium and program according to the present invention, when the size of the object after perspective transformation becomes smaller than a given threshold value, the image of the outline of the object is almost visible. It is characterized by disappearing. In this way, if the size of the object after perspective transformation becomes smaller than a given threshold, the contour image is made completely transparent and the relative thickness of the contour is conspicuous. It is possible to reliably prevent problems that occur.

The game system, information storage medium, and program according to the present invention are characterized in that an image of the outline of an object is drawn in a region outside the outline of the object. In this way, when drawing a contour line in the outer region of the contour of the object, it is possible to adopt a method of changing the color of the contour line according to the distance from the viewpoint or the size of the object after perspective transformation. desirable.

When the outline is drawn in the outer area of the object outline, it is sufficient that at least a part of the outline is drawn in the outer area, and the other part may be drawn in the inner area.

The game system, information storage medium, and program according to the present invention are characterized in that an image of the outline of an object is drawn in an inner area of the outline of the object. Thus, when drawing an outline in the inner area of the outline of the object, a method of changing the translucency (darkness) of the outline according to the distance from the viewpoint and the size of the object after perspective transformation It is desirable to adopt.

[0034]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings.

1. Configuration FIG. 1 shows an example of a functional block diagram of a game system (image generation system) of the present embodiment. In this figure, the present embodiment only needs to include at least the processing unit 100 (or the processing unit 100 and the storage unit 17).
0 may be included), and the other blocks may be arbitrary constituent elements.

The operation unit 160 is for the player to input operation data, and the function can be realized by hardware such as a lever, a button, a microphone, or a housing.

The storage unit 170 includes the processing unit 100 and the communication unit 1.
It becomes a work area such as 96, and its function is RAM
It can be realized by hardware such as.

An information storage medium (storage medium usable by a computer) 180 stores information such as programs and data, and functions thereof are optical disks (C
D, DVD), magneto-optical disk (MO), magnetic disk, hard disk, magnetic tape, or memory (RO)
It can be realized by hardware such as M). Processing unit 10
0 performs various processes of the present invention (this embodiment) based on information stored in the information storage medium 180. That is, the information storage medium 180 stores information (program or data) for executing the means of the present invention (this embodiment) (particularly, the blocks included in the processing unit 100).

A part or all of the information stored in the information storage medium 180 is transferred to the storage unit 170 when the system is powered on. Information storage medium 1
80 includes a program for performing the process of the present invention, image data, sound data, display object shape data, information for instructing the process of the present invention, or information for performing the process in accordance with the instruction. Can be made.

The display unit 190 outputs an image generated by this embodiment, and its function is CRT,
LCD or HMD (Head Mounted Display)
It can be realized by hardware such as.

The sound output unit 192 outputs the sound generated by this embodiment, and its function can be realized by hardware such as a speaker.

The portable information storage device 194 stores player personal data, game save data, and the like. As the portable information storage device 194, a memory card, a portable game device, and the like are considered. Can do.

The communication unit 196 performs various controls for communicating with the outside (for example, a host device or other game system), and functions as various processors or communication ASICs. This can be realized by hardware or a program.

It should be noted that the program or data for executing the means of the present invention (this embodiment) is distributed from the information storage medium of the host device (server) to the information storage medium 180 via the network and the communication unit 196. It may be. Use of such an information storage medium of the host device (server) is also included in the scope of the present invention.

The processing unit 100 (processor) is an operation unit 1
Various processes such as a game process, an image generation process, or a sound generation process are performed based on operation data from 60, a program, and the like. The functions of the processing unit 100 can be realized by hardware such as various processors (CPU, DSP, etc.) or ASIC (gate array, etc.) and a given program (game program).

Here, the game processing performed by the processing unit 100 includes coin (price) acceptance processing, various mode setting processing, game progress processing, selection screen setting processing, and object (one or more primitive surfaces). Processing for obtaining the position and rotation angle (rotation angle around X, Y or Z axis),
Processing to move an object (motion processing), processing to obtain the viewpoint position (virtual camera position) and line-of-sight angle (virtual camera rotation angle), processing to place an object such as a map object in the object space, hit check processing, A process for calculating game results (results, results), a process for a plurality of players to play in a common game space, or a game over process can be considered.

Further, the processing unit 100 generates an image that can be seen from a given viewpoint (virtual camera) in the object space, for example, based on the above game processing result, and outputs it to the display unit 190.

Further, the processing unit 100 performs various kinds of sound processing based on the above-mentioned game processing result, and performs BGM, sound effects,
Alternatively, sound such as voice is generated and output to the sound output unit 192.

Note that all of the functions of the processing unit 100 may be realized by hardware, or all of them may be realized by a program. Alternatively, it may be realized by both hardware and a program.

The processing unit 100 includes a geometry processing unit 11.
0, a virtual object generation unit 112, a contour line image change unit 114, and a drawing unit 120.

Here, the geometry processing unit 110 performs various types of geometry processing (three-dimensional calculation) such as coordinate transformation, clipping processing, perspective transformation, or light source calculation on the object. The drawing data (position coordinates, texture coordinates, color (luminance) data, normal vector or α value, etc. given to the vertices) obtained by the geometry processing is stored in the main storage unit 172 of the storage unit 170 and saved. Is done.

The virtual object generator 112 performs processing for generating a virtual object to be mapped in the mapping image. As will be described later, the mapping image is generated by the mapping image generation unit 122 included in the drawing unit 120.
Produces.

In this embodiment, this virtual object (virtual polygon in a narrow sense) contains all or part of the image of the object after perspective transformation (after transformation to the screen coordinate system), and the object after perspective transformation. The object changes its size according to the size of the object. That is, the size of the object changes according to the area occupied by the object on the screen. Since the mapping image generated by the mapping image generation unit 122 is mapped to a virtual object whose size changes according to the area occupied by the object in the screen in this way, texture mapping is performed. Processing and virtual object drawing processing can be made more efficient.

The contour image changing unit 114 changes the contour image to be given to the object in accordance with the distance from the viewpoint and the size of the object after perspective transformation (relative size with respect to the pixel). Process.

More specifically, the contour line image changing unit 114.
Is a process (first operation) for bringing the color of the contour line closer to a given second color according to the distance from the viewpoint and the size of the object after perspective transformation (the size of the object on the screen). , A process for setting the second color, a process for obtaining an interpolation coefficient when the first color and the second color are interpolated, etc.).

Alternatively, the contour line image changing unit 114 performs processing for making the contour image of the object transparent according to the distance from the viewpoint and the size of the object. That is, a process for translucently compositing an object image and an outline image of an object with a translucency determined according to the distance from the viewpoint and the size of the object after perspective transformation (a process for determining the translucency, a drawing order) Process to decide).

The drawing unit 120 (object / outline drawing unit) is an object (model) after geometry processing.
In addition, a process for drawing an object outline in a drawing area 174 (an area where image information can be stored in units of pixels such as a frame buffer and a work buffer) is performed.

More specifically, the drawing unit 120 generates an image of the outline of the object generated based on the object image (for example, the image of the object after perspective transformation, the image of the object on the drawing area), Drawing processing is performed so that the drawing is performed in the outer region and the inner region of the contour of the object.

The drawing unit 120 includes a mapping image generation unit 1
22, texture mapping unit 130, synthesis unit 132,
A hidden surface removal unit 134 is included.

The mapping image generation unit 122 generates a mapping image in which the object color information is set in the inner area of the object outline and the outline color information is set in the outer area of the object outline.

The texture mapping unit 130 performs processing for mapping the texture stored in the texture storage unit 176 to the object.

More specifically, the texture mapping unit 130 performs processing for mapping the mapping image generated by the mapping image generation unit 122 to the virtual object generated by the virtual object generation unit 112. In this case, the texture mapping unit 13
0 is a texel interpolation method (in a narrow sense) while shifting the generated mapping image by a value smaller than, for example, one texel (pixel) (for example, shifting from the texture coordinate obtained based on the drawing position of the mapping image). Is mapped to a virtual object with a binier filter. As a result, the outline of the object can be drawn with a small processing load.

The synthesizing unit 132 performs a mask synthesizing process and a semi-transparent process using the α value. The α value (A value) is information stored in association with each pixel, for example, plus alpha information other than color information. The α value can be used as mask information, translucency (equivalent to transparency and opacity), bump information, and the like.

The hidden surface removal unit 134 performs hidden surface removal according to the algorithm of the Z buffer method, using a Z buffer (Z plane) in which Z values (depth values) are stored.

For example, when a contour line is drawn in the outer region of the contour of the object, the Z value obtained based on the object information (vertex coordinates, etc.) is set in the virtual object, and based on the set Z value. It is desirable to perform hidden surface removal for virtual objects. In this way, the Z value (depth value) obtained based on the object information is simply set to the virtual object, and an appropriate Z value that enables proper hidden surface removal can be obtained for the contour line. It becomes possible to set.

On the other hand, when a contour line is drawn in the inner area of the contour of the object, the Z value of the object at the contour drawing position is set as the Z value of the contour line to perform the hidden surface of the contour line. Is desirable. In this way, it becomes possible to set an appropriate Z value for the contour line, and it is possible to realize an appropriate hidden surface removal with another object.

It should be noted that the hidden surface may be erased by a depth sorting method (Z sort method) in which the primitive surfaces are sorted according to the distance from the viewpoint and the primitive surfaces are drawn in order from the viewpoint.

The game system of this embodiment has 1
A system dedicated to the single player mode in which only a human player can play may be used, or a system including not only such a single player mode but also a multiplayer mode in which a plurality of players can play.

When a plurality of players play,
The game images and game sounds to be provided to the plurality of players may be generated using one terminal, or may be generated using a plurality of terminals connected via a network (transmission line, communication line) or the like. Also good.

2. 2. Features of this Embodiment 2.1 Contour Line Image Change Processing FIG. 2 shows an example of a game image generated by the game system of this embodiment. As shown in FIG. 2, according to the present embodiment, a thick edge line is drawn along the outline of the object OB composed of polygons, which is familiar to ordinary people in cartoons and animations. A cell-like image has been successfully generated.

However, in such contour line drawing processing, when the distance from the viewpoint is long (when the size of the object after perspective transformation is small), the relative thickness of the contour line is unnecessary. It turns out that the problem of being conspicuous (highlighted) occurs.

In other words, in a three-dimensional game, the player's viewpoint (virtual camera) in accordance with the player's operation input, etc.
Moves to an arbitrary position, and an object representing a character or the like also moves to an arbitrary position. Accordingly, the distance between the player's viewpoint and the object also changes variously, and the size of the object after the perspective transformation (the relative size of the object with respect to the pixel on the screen) also changes variously. .

As described above, when an outline having a certain thickness (for example, 1 pixel) is drawn on an object whose size may change variously, the following problem occurs.

That is, when the distance between the viewpoint and the object OB is short as shown by A1 in FIG. 3 (when the area occupied by the object on the screen is large), the thickness of the outline EDL of the object OB is not so large. It does not stand out and does not look like an unnatural image.

However, as shown by A2 and A3 in FIG. 3, when the distance from the viewpoint is increased (when the occupied area of the object on the screen is reduced), the contour line EDL is obtained.
The thickness of the image becomes unnecessarily noticeable and an unnatural image is generated.

In particular, as shown in A3, the object OB
When the total number of pixels (the number of vertical pixels × the number of horizontal pixels) is, for example, 1 to 10 pixels, an image that looks as if the object OB is filled with the color of the contour line EDL is generated. That is, the object O
Taking the case where the color of B is red and the color of the contour line EDL is black as an example, the image of OB that should originally look red appears as if it were a black dot.

Therefore, in this embodiment, the image of the outline of the object is changed according to the distance from the viewpoint and the size of the object after the perspective transformation. In this case, as a method of changing the contour image, for example, a method of changing the color of the contour line and a method of changing the translucency (darkness) of the contour line can be considered.

2.2 Contour Line Color Change Processing When changing the color of the contour line, the distance from the viewpoint is increased, or the size of the object after perspective transformation (the size of the object with respect to the pixel) is increased. The smaller it is,
For example, the color of the outline of the object is brought closer to a given second color.

More specifically, as indicated by B1 and B2 in FIG. 4, the outline EDL of the object OB increases as the distance from the viewpoint increases (the size of the object after perspective transformation decreases). The color of the contour line EDL is determined by performing interpolation processing of the first and second colors so that the color gradually changes from the dark first color to the light second color. As shown in B3, when the distance from the viewpoint is sufficiently long (when the size of the object after perspective transformation is sufficiently small), the color of the contour line EDL is very thin. So that it becomes the color.

In this way, A2 in FIG. 3 and B in FIG.
As can be seen from a comparison of 2, it is possible to solve the problem that the thickness of the contour line EDL is unnecessarily noticeable. Further, as apparent from comparison between A3 in FIG. 3 and B3 in FIG. 4, it is possible to solve the problem of generating an image that looks as if the object OB is filled with the color of the contour line EDL. In other words, taking the case where the color of the object OB is red and the color of the contour line EDL is black as an example, even if the distance from the viewpoint is sufficiently long, the color of the OB is not filled in black. Can produce more natural images.

Various methods can be considered as a method for controlling the color of the contour line according to the distance from the viewpoint and the size of the object.

For example, in FIG. 5A, when the distance from the viewpoint becomes longer than the threshold value VTN, the color of the outline starts to change from the short distance color CN (first color), It gradually approaches the light color CF (second color) for long distances. As a result, the outline gradually becomes inconspicuous.

The distance from the viewpoint is the threshold value VTF.
When the distance is longer, the outline color is CF for long distance.
And the color of the outline of the object becomes very light as indicated by B3 in FIG. As a result, it is possible to solve the problem that the object looks as if it is filled with the outline color.

In FIG. 5B, when the size of the object becomes smaller than the threshold value VTN, the color of the outline starts to change from CN and gradually approaches CF.

When the size of the object becomes smaller than the threshold value VTF, the color of the contour line is set to CF, and the contour line of the object becomes very thin as indicated by B3 in FIG.

As described above, if the color of the contour line is changed in accordance with the distance from the viewpoint and the size of the object after the perspective transformation, the problem described with reference to FIG. 3 can be effectively solved.

2.3 Processing for changing the translucency of the contour line When changing the translucency of the contour line, the distance from the viewpoint or the size of the object after perspective transformation decreases, Make the image more transparent. For example, translucent composition (α composition) of an object image and an object outline image with translucency (equivalent to transparency and opacity) determined according to the distance from the viewpoint and the size of the object after perspective transformation To do.

More specifically, as indicated by C1 and C2 in FIG. 6, the outline EDL of the object OB increases as the distance from the viewpoint increases (the size of the object after perspective transformation decreases). The translucency is changed so that the contour line EDL becomes more transparent. Then, as shown in C3, when the distance from the viewpoint is sufficiently long (when the size of the object after perspective transformation is sufficiently small), the image of the contour line EDL is almost invisible. To do.

In this way, A2 in FIG. 3 and C in FIG.
As can be seen from a comparison of 2, it is possible to solve the problem that the thickness of the contour line EDL is unnecessarily noticeable. Further, as apparent from comparison between A3 in FIG. 3 and C3 in FIG. 6, it is possible to solve the problem that an image appears as if the object OB was filled with the color of the outline EDL. In other words, taking the case where the color of the object OB is red and the color of the contour line EDL is black as an example, even if the distance from the viewpoint is sufficiently long, the red color that should be originally visible without being blacked out. And a more natural image can be generated.

Various methods can be considered as a method for controlling the translucency of the contour line according to the distance from the viewpoint and the size of the object.

For example, in FIG. 7A, when the distance from the viewpoint is longer than the threshold value VTN, the translucency αT
Starts to change from αTN for short distance, and the outline of the object starts to become transparent. As a result, the outline gradually becomes inconspicuous.

The distance from the viewpoint is the threshold value VTF.
The translucency αT is a long-range α
As shown in C3 in FIG. 6, for example, the object outline is completely transparent (not visible).
This prevents the object from being painted with the outline color.

In FIG. 7B, when the size of the object becomes smaller than the threshold value VTN, the translucency αT starts to change from αTN, and the outline of the object starts to become transparent.

When the size of the object becomes smaller than the threshold value VTF, the translucency αT becomes αT
For example, the outline of the object becomes completely transparent (not visible) as indicated by C3 in FIG.

As described above, the problem described with reference to FIG. 3 can be effectively solved by changing the translucency of the contour line in accordance with the distance from the viewpoint and the size of the object after the perspective transformation.

It should be noted that the distance from the viewpoint in FIGS. 5A and 7A is the depth distance (Z value) of the object (representative point of the object) from the viewpoint of reducing the processing load.
Although it is particularly desirable, it is not limited to this. For example, it may be a linear distance between the viewpoint and the object. In addition to the depth distance and the straight line distance, any equivalent parameter that can obtain the same effect as when the depth distance or the straight line distance is changed may be used.

The size of the object in FIGS. 5B and 7B is the total number of pixels of the object (the number of vertical pixels × the number of horizontal pixels) from the viewpoint of reducing the processing load. Although it is desirable, it is not limited to this. For example, it may be one of the number of vertical pixels or the number of horizontal pixels of the object. Alternatively, in addition to the number of pixels, any equivalent parameter that can obtain the same effect as that obtained by changing the number of pixels may be used.

2.4 Setting Color and Translucency As shown in FIG. 8A, in this type of three-dimensional game, when the object OB moves, the object OB and the viewpoint VP (virtual camera) In many cases, the VP follows the OB while keeping the distance between the VP and the ZVB at a substantially constant distance.

In such a scene, as shown in FIG. 4 and FIG. 6, if the color and translucency of the contour line frequently change according to the distance from the viewpoint and the size of the object, it is unnatural for the player. There arises a problem that an image that appears to be generated is generated.

Therefore, in this embodiment, when the distance from the viewpoint VP is near the distance ZVB when the viewpoint VP follows the object OB (hereinafter referred to as the following movement mode), the contour of the OB is obtained. Make sure that the color and translucency of the line is kept almost constant. Alternatively, when the size of the object OB after the perspective transformation is around the size of the OB in the follow movement mode (the size at the distance ZVB), the OB
So that the color and translucency of the contour line are kept substantially constant. More specifically, the threshold VTN is set to a distance farther than the distance ZVB (a value smaller than the size of the OB at the time of tracking).
Is set in advance. In this way, FIG.
As is apparent from the function characteristics of (B) and FIGS. 7 (A) and (B), the color and translucency of the contour line do not change during the follow movement mode. Thereby, the above-mentioned problem that an unnatural image is generated in the follow-up movement mode of the viewpoint VP to the OB can be solved.

Then, when an event occurs, the follow-up movement mode of the viewpoint VP with respect to the object OB is removed, and the distance between VP and OB is longer than the threshold value VTN (when the size of the object is reduced), As shown in FIG. 6, the color and translucency of the contour line change according to the distance from the viewpoint VP (the size of the OB). This can also solve the problem that the distance between the viewpoint and the object is increased due to the occurrence of the event, and the relative thickness of the contour line is unnecessarily noticeable.

Further, FIGS. 5A, 5B, 7A,
By setting the upper limit side threshold value VTF (given threshold value) as shown in (B), the following effects can be obtained.

That is, when the size of the object OB is reduced as shown by A3 in FIG. 3, the outline EDL is not a thin second color, or the outline EDL is completely transparent. Otherwise, an unnatural image is generated that looks as if OB is painted in the color of EDL.

Therefore, the size of the object OB is as shown in FIG.
The threshold value VTF is set so that the contour line EDL becomes a second light color when the size is as shown in A3 of FIG. . In this way, when the size of the object OB is as shown in A3 of FIG. 3, the contour line EDL becomes inconspicuous as shown in B3 of FIG. 4 and C3 of FIG.
The problem of generating an unnatural image as indicated by A3 in FIG. 3 can be prevented.

Further, by changing the color of the contour line and the translucency between the threshold values VTN and VTF, it is possible to solve the problem that the player notices how the color of the contour line and the translucency change. .

2.5 Advantages and Problems In the method for controlling the color of the outline shown in FIGS. 4 to 5B, the translucency of the outline shown in FIGS. 6 to 7B is controlled. Unlike the method, translucent processing between the contour image and the object image is not required. Therefore, there is an advantage that processing for managing the drawing order of contour lines becomes unnecessary, and Z sort processing with other objects becomes unnecessary.

On the other hand, the method for controlling the color of the contour line in FIGS. 4 to 5B has the following problems.

That is, the object O as shown in FIG.
There is no problem when the color of B is a single color (for example, red). However, it is rare that the color of the object OB is a single color, and the color of the object OB to which the texture is mapped is usually two or more colors as shown in FIG. 9B.

In such a case, even if it is attempted to make the thickness of the contour line EDL inconspicuous by the method of controlling the color of the contour line, there is a case where the effect is not so great.

That is, in the case of FIG. 9A, if the color of the contour line EDL is changed to light red, for example, as the distance from the viewpoint increases, the size of the object OB becomes very small. In addition, the thickness of the outline becomes inconspicuous.

However, in the case of FIG. 9B, even if the color of the contour line EDL is changed to light red as the distance from the viewpoint increases, the contour line ED in the portion indicated by D1 is changed.
Although the thickness of L becomes inconspicuous, since the difference between the blue and red colors is visible in the portion indicated by D2, the thickness of the outline EDL remains conspicuous.

On the other hand, in the method of controlling the translucency of the contour line in FIGS. 6 to 7B, even when the color of the object OB is two or more as shown in FIG. 9B, The thickness of the contour line EDL when the distance from the viewpoint is long can be made inconspicuous. That is, in the method for controlling the translucency of the contour line, the color of the contour line EDL approaches the color red of the object in the portion indicated by D1, and the contour line EDL in the portion indicated by D2. This is because the color of becomes closer to blue which is the color of the object in that portion.

As described above, when the object OB has two or more colors, the method of controlling the translucency of the outline is more advantageous.

However, the method for controlling the semi-transparency of the contour line has a disadvantage that a process for managing the drawing order of the contour lines is required because the translucency process is performed.

In particular, when the contour line EDL is drawn in the outer region of the contour ED of the object OB as shown in FIG. 10A, Z sort processing between the contour line EDL and another object OB2 (background) is performed. I need it.

In this case, if the Z sort process (hidden surface removal) is not properly performed, there is a possibility that the contour line EDL may be hidden behind the object OB2 and become invisible as shown in FIG. is there.

Further, even if the Z sort process is properly performed, the color of the contour line EDL differs between the portion indicated by E1 and the portion indicated by E2 in FIG. An image is generated.

Therefore, the method of controlling the translucency of the contour line is not suitable when the contour line EDL is drawn in the outer region of the contour ED as shown in FIG. 10A, and FIG.
This is an optimal method when the contour line EDL is drawn in the inner region as shown in FIG. When the contour line is drawn in the inner area of the contour, the object is drawn first, and then the drawing order of drawing the contour line is followed.
This is because the problems shown in (A) and (B) do not occur, and the object and the outline are appropriately translucently combined.

In other words, when the contour line EDL is drawn in the outer region of the contour ED of the object OB as shown in FIG. 10A, the contour line described with reference to FIGS. The method of controlling the color of the image becomes convenient. Although the method for controlling the color of the contour line has the problems described in FIGS. 9A and 9B, it is not necessary to consider the drawing order of the contour line.
This is because there is little possibility that problems such as those shown in FIGS.

2.6 Outline Drawing Using Bilinear Filter / Texture Mapping In this embodiment,
Bilinear filter method (texel interpolation method in a broad sense)
The contour line is drawn by effectively using the texture mapping.

That is, in the texture mapping, the pixel position and the texel position may be shifted.

In this case, as shown in FIG. 12, in the point sampling method, pixels (sampling points) are used.
The color CP of P (image information in a broad sense) is the color CA of the texel TA closest to P.

On the other hand, in the bilinear filter system, the P color CP is determined by the texels TA, TB, TC, TD around P.
The colors CA, CB, CC and CD are interpolated.

More specifically, based on the coordinates of TA to TD and the coordinates of P, the coordinate ratio β: 1-β (0 ≦ β in the X-axis direction)
≦ 1) and the coordinate ratio γ in the Y-axis direction: 1−γ (0 ≦ γ ≦ 1)
Ask for.

In this case, the P color CP (output color in the bilinear filter system) is expressed by the following equation.

CP = (1−β) × (1−γ) × CA + β × (1−γ) × CB + (1−β) × γ × CC + β × γ × CD (1) In this embodiment, in this way In contrast, in the bilinear filter method, attention is paid to the fact that the color is automatically interpolated, and the outline is drawn.

More specifically, as shown in FIG. 13A, a mapping image in which the object color is set in the inner area of the outline ED of the object OB and the outline color is set in the outer area of the outline ED. Generate. Then, as shown by F1 in FIG. 14, this mapping image is set as a texture. Then, as shown in F2 of FIG. 14, when mapping this texture to a virtual polygon (virtual object in a broad sense) by the bilinear filter method,
The texture coordinates given to the vertices of the virtual polygon are shifted (shifted, moved) in the lower right direction by, for example, (0.5, 0.5).

By doing so, the color of each pixel of the mapping image is automatically blurred in the surrounding pixels by the bilinear filter type interpolation function. As a result, as shown in FIG.
In the vicinity of the outline of B, the object color and the outline color are mixed, and the outline EDL is drawn along the outline of the object OB.

Then, according to the method of this embodiment, an image of a contour line can be generated by 2D (two-dimensional) processing on the drawing area. Therefore, three-dimensional processing such as processing for obtaining an angle formed by the line-of-sight vector and the normal vector is not required, and the CPU
Can reduce the processing load.

Also, according to the method of the present embodiment, the drawing process in the drawing area may be performed at least once (or twice) for drawing the virtual polygon. Therefore, it is possible to reduce the number of drawing processes necessary for generating the contour image, and to significantly reduce the processing load on the drawing processor.

Note that the vertices VVX1, VV of the virtual polygon
The coordinates of X2, VVX3, and VVX4 are (X, Y) = (X
0, Y0), (X0, Y1), (X1, Y1), (X1,
Y0). In this case, the texture coordinates (U, V) given to the vertices VVX1, VVX2, VVX3, VVX4 of the virtual polygon are respectively (X0, Y0),
If (X0, Y1), (X1, Y1), and (X1, Y0) are set, the pixel position matches the texel position without any deviation. Therefore, the color of each pixel does not exude to surrounding pixels.

On the other hand, the vertex VVX of the virtual polygon
1, texture coordinates (U, V) given to VVX2, VVX3, and VVX4 are (X0 + 0.5, Y0 + 0.
5), (X0 + 0.5, Y1 + 0.5), (X1 + 0.
5, Y1 + 0.5), (X1 + 0.5, Y0 + 0.5)
If set to, the pixel position and the texel position are shifted. Therefore, the color of each pixel exudes to surrounding pixels by the bilinear filter type interpolation function.

More specifically, the texture coordinates are set to 0.5.
When bilinear filter type texture mapping is performed by shifting pixels (texels) in the lower right direction, β = γ = 1/2 in the above equation (1). Accordingly, in FIG. 15, texels T44, T45, T54, T
If the color of 55 is C44, C45, C54, C55,
The color CP44 of the pixel P44 is as follows.

[0134]   CP44 = (C44 + C45 + C54 + C55) / 4 (2)

Accordingly, when bilinear filter type texture mapping is performed while shifting the texture coordinates in the lower right direction, as shown in FIG.
Color C44, that is, the original color of the pixel P44 oozes out by 1/4 with respect to the pixels P33, P34, P43, and P44. As a result, the contour E as shown in FIG. 13B in which the contour color and the object color are mixed.
A DL image can be generated.

2.7 Generation of Virtual Polygon Virtual polygons to be mapped in the mapping image in FIG. 14 can have various shapes.

In this case, when a screen-sized polygon is used as the virtual polygon, the entire screen is subjected to bilinear filter type interpolation processing.

However, it has been found that if a screen-sized polygon is used as a virtual polygon in this way, the processing is wasted and the contour drawing process cannot be made more efficient.

That is, in a three-dimensional game, the player's viewpoint moves to an arbitrary position in accordance with the player's operation input, and an object representing a character or the like also moves to an arbitrary position. Therefore, the distance between the player's viewpoint and the object also changes variously, and the size of the object after perspective transformation (the area occupied by the object on the screen) also changes according to the distance between the viewpoint and the object. Will come to do.

For example, as shown in FIG. 16A, when the distance between the viewpoint and the object OB is short, the size of the object OB after the perspective transformation is large (the occupied area on the screen is large).

On the other hand, as shown in FIG. 16B, when the distance between the viewpoint and the object OB is long, the size of the object OB after the perspective transformation is small (occupied area on the screen is small). .

As shown in FIG. 16A, when the area occupied by the object OB in the screen is large, even if a screen-sized polygon is used as a virtual polygon to be mapped in the mapping image, it is not very efficient. Absent.

However, as shown in FIG. 16B, when the area occupied by the object OB in the screen is small,
If screen-size polygons are used, useless drawing processing is performed, and the processing load becomes unnecessarily heavy.

Therefore, in this embodiment, the image of the object OB after perspective transformation is included, and the size changes according to the size of the OB after perspective transformation.
A virtual polygon VPL shown in FIG. Then, a mapping image (FIG. 13) is applied to the virtual polygon VPL.
(A) is mapped.

In this way, the viewpoint and the object O
When the distance from B changes and the area occupied by OB in the screen changes, the size of the virtual polygon VPL also changes accordingly. For example, as the distance between the viewpoint and OB increases, the size of the virtual polygon VPL decreases. Therefore, the efficiency of the drawing process can be improved, and the load of the drawing process can be optimized.

If the object is composed of part objects, a virtual polygon may be generated for each part object. When processing is performed only on a part of the object (for example, eyes and mouth), a virtual polygon that includes a part of the object after perspective transformation may be generated.

Various methods can be considered as a method for generating a virtual polygon.

In the first method, as shown in FIGS. 17A and 17B, the vertices of the object OB after perspective transformation (definition points including control points of a free-form surface in a broad sense) VX1 to VX.
A virtual polygon VPL is generated based on coordinates such as X6.

More specifically, the minimum value XMIN, YMIN, maximum value XM of the X and Y coordinates of the vertex of the object OB.
Based on AX and YMAX, vertices VVX1 (XMIN, YMIN), VVX2 (XMI) of virtual polygon VPL
N, YMAX), VVX3 (XMAX, YMAX), V
VX4 (XMAX, YMIN) is obtained, and virtual polygon V
PL is generated.

According to the first method, the virtual polygon V
Since the size of PL can be optimally reduced according to the size of the object OB after the perspective transformation, the virtual polygon VP
There is an advantage that the load of the L drawing process is reduced. On the other hand, when there are many vertices of the object OB, there is a drawback that the processing load for obtaining the minimum and maximum values of the X and Y coordinates of those vertices becomes heavy.

In the second method, as shown in FIG. 18A, a simple object SO that contains an object OB.
B (bounding box, bounding volume) is used. This simple object SOB is used for hit check processing of the object OB and the like. In the present embodiment, this simple object S
Simple object SO after perspective transformation using OB effectively
Based on the coordinates of the vertex of B (definition point in a broad sense), a virtual polygon VPL is generated.

More specifically, as shown in FIG. 18B, the vertex VSX of the simple object SOB after perspective transformation.
The vertices VVX1 to VVX4 of the virtual polygon VPL are obtained based on the minimum and maximum values of the X and Y coordinates of 1 to VSX8 to generate the virtual polygon VPL.

According to this second method, the object O
Since the simple object SOB having a smaller number of vertices than B is used, there is an advantage that the processing load for obtaining the minimum and maximum values of the X and Y coordinates of the vertices is reduced. On the other hand, since the size of the virtual polygon VPL is larger than that of the first method, there is a drawback that the drawing processing load of the virtual polygon VPL becomes heavier than that of the first method.

Note that the size of the virtual polygon VPL may be slightly larger in the vertical and horizontal directions than the sizes shown in FIGS. 17A, 17B, and 18B (for example, one pixel). Make it bigger). In particular, when a contour line is drawn in the outer region of the contour of the object, a technique for scaling the size of the virtual polygon in this way is effective.

Further, the method of changing the size of the virtual polygon according to the size of the object after the perspective transformation is not limited to the first and second methods described above. For example, the size of the virtual polygon may be appropriately changed according to the distance between the viewpoint and the object.

Also, FIG. 4, FIG. 5 (B), FIG. 6, FIG.
As described in (B), when the translucency of the contour line is changed according to the size of the object after the perspective transformation, the virtual generated by the method of FIGS. 16 (A) to 18 (B). The size (number of pixels) of the polygon (virtual object) may be obtained, and the translucency of the contour line may be changed based on the size.

2.8 Outline Image Next, a method for generating an outline image of an object will be described.

In this embodiment, an edge line image is generated using the texture mapping of the bilinear filter method described in 2.6 above.

2.8.1 More specifically, the mapping image is generated. First, as preprocessing, the work buffer (effect buffer) is set to contour image information (RL, G
L, BL, αL). That is, the color of each pixel is set to the outline color (RL, GL, BL), and
The α value is set to αL (= 0).

Next, the object OB to be contoured is drawn in the work buffer. In this case, the α value (A value) of the vertex of the object OB is set to αJ (> 0). For the sake of simplicity, it is assumed that the color of the object OB is a single color (RJ, GJ, BJ).

As described above, an image (mapping image) as shown in FIG. 19 is drawn in the work buffer.

That is, the inner area of the contour ED of the object OB is set to the OB color (RJ, GJ, BJ), and the outer area of the contour ED is set to the outline color (RL, GL, BL). The α value of the inner area is set to αJ (> 0), and the α value of the outer area is set to αL (= 0).

Note that the setting of the α value shown in FIG. 19 is merely an example, and it is sufficient that at least the α value of the outer region and the α value of the inner region are set to different values.

2.8.2 Texture Mapping by Bilinear Filter Method Next, the mapping image on the work buffer shown in FIG. 19 is drawn at the same position on the frame buffer.

More specifically, as shown in FIG. 20, while mapping the mapping image on the work buffer to a virtual polygon (virtual object in a broad sense), the virtual polygon is drawn on the frame buffer.

In this case, FIGS. 16A to 18B.
As described above, a virtual polygon (effect area) that contains an object and changes its size according to the size of the object after perspective transformation is generated, and a work buffer is created for the virtual polygon. Map the top mapping image.

In addition, when this texture mapping is performed, a bilinear filter (texel interpolation) method is selected, and the texture coordinates are, for example, +
Shift (shift) by 0.5 pixels (texels), and pass only pixels with α> 0 (pixels where α is not 0) in the source α test (α test for the mapping image as the writing source).

Thus, an image as shown in FIG. 21 in which the outline EDL is given to the object OB is generated.

That is, by selecting the bilinear filter and shifting the texture coordinates, interpolation of the color and α value (A value) set for each pixel of the mapping image on the work buffer is performed.

For example, the position of the drawing pixel is (X, Y).
If the texture coordinates U and V are shifted by +0.5 pixel (texel), at the time of texture sampling, (X, Y), (X + 1, Y), (X, Y +
The color and α value at the positions of the four pixels 1) and (X + 1, Y + 1) are referred to. As a result, the color and α value of the texel to be finally drawn are the average of the color and α value of the above four pixels. For example, as shown in FIG. 22, when the texture coordinates are shifted in the lower right direction, the RGB and α values of the pixels B, C, and D ooze out from the pixel A by ¼. This is expressed by the following equation.

[0171] R = (RA + RB + RC + RD) / 4 G = (GA + GB + GC + GD) / 4 B = (BA + BB + BC + BD) / 4 α = (αA + αB + αC + αD) / 4 (3)

In the above equation, R, G, B, and α are the color and α value obtained by interpolation (the color and α value of pixel A after interpolation). Also, (RA, GA, BA, αA),
(RB, GB, BB, αB), (RC, GC, BC, α
C) (RD, GD, BD, αD) are the colors and α values of the pixels A, B, C, D before interpolation, respectively.

As described above, when the texture coordinates are shifted by 0.5 pixels in the lower right direction, pixel B,
The RGB values of C and D ooze out from the pixel A by 1/4 each. Therefore, in the portion indicated by H1 in FIG.
As shown in FIG. 3 (A), the color (RJ, GJ, BJ) of the object OB and the color of the contour line (RL, GL, BL) are synthesized in the inner region of the contour ED, and the contour is formed in the inner region of the contour ED. An image of the line EDL is generated.

Note that the colors of the contour lines (RL, GL, B
L) is a color set in the outer region of the contour ED in the work buffer as shown in FIG.

On the other hand, in the portion indicated by H2 in FIG.
As shown in FIG. 3B, the color (RJ, GJ, BJ) of the object OB and the color of the outline (RL, GL, BL) are synthesized in the outer region of the contour ED, and the contour is formed in the outer region of the contour ED. An image of the line EDL is generated. As a result, as shown in FIG.
The contour line EDL is drawn along the contour ED of B.

In the present embodiment, not only the color but also the α value are subjected to interpolation processing by the bilinear filter. Accordingly, the α value set for the contour line EDL is also an α value obtained by combining αJ of the object OB and αL of the contour line.

The above will be described in more detail as follows.

(I) Pixels in which all the surrounding pixels to be referred to have a contour color In the pixels indicated by I1 in FIG. 23A and I2 in FIG. 23B, the surrounding pixels (texels) ) RG
The B and α values are all (RL, GL, BL, αL). Therefore, in the above equation (3) (RA, GA, B
A, αA) = (RB, GB, BB, αB) = (RC, G
C, BC, αC) = (RD, GD, BD, αD) = (R
L, GL, BL, αL), the RGB and α values after interpolation are (R, G, B, α) = (RL, GL, BL, α
L).

At this time, since α = αL = 0 is set (see FIG. 19), the source α test that passes only pixels with α> 0 fails, and drawing is prohibited for these pixels. The

(II) Pixels to which both the pixel of the outline color and the pixel of the object color are referred. In the pixel as shown in I3 of FIG. 23A or I4 of FIG. RL, GL, BL, α
L) pixels (texels) and (RJ, GJ, BJ, α
J) pixels (texels) are mixed. in this case,
When the number of pixels (RJ, GJ, BJ, αJ) is K, (R, G, B, α) after interpolation according to the above equation (3) is as follows.

[0181] R = {RJ × K + RL × (4-K)} / 4 G = {GJ × K + GL × (4-K)} / 4 B = {BJ × K + BL × (4-K)} / 4 α = {αJ × K + αL × (4-K)} / 4 (4)

As shown in the above equation (4), the color of the pixel after interpolation is the color of the object OB (RJ, GJ, BJ, α
J) and the outline colors (RL, GL, BL, αL) are mixed.

Also, since αJ> 0, 1 ≦ K ≦ 3, and αL = 0, 0 <α <αJ, and the source α test that passes only pixels with α> 0 is passed, and for these pixels, Will always be drawn.

(III) Pixels in which all the surrounding pixels referred to are the object color In the pixels indicated by I5 in FIG. 23A and I6 in FIG. 23B, the surrounding pixels (texels) to be referred to RG
The B and α values are all (RJ, GJ, BJ, αJ). Therefore, in the above equation (3) (RA, GA, B
A, αA) = (RB, GB, BB, αB) = (RC, G
C, BC, αC) = (RD, GD, BD, αD) = (R
J, GJ, BJ, αJ), the RGB and α values after interpolation are (R, G, B, α) = (RJ, GJ, BJ, α
J).

At this time, since α = αJ> 0 is set (see FIG. 19), the source α test in which only pixels with α> 0 are passed is passed, and the object color remains unchanged for these pixels. It will be drawn.

As described above, the frame buffer shown in FIG.
The image as shown in 1 can be drawn.

In FIG. 21, the contour line EDL is also drawn in the region outside the contour ED of the object OB. Therefore, in this case, it is desirable to employ a method of controlling the color of the contour line according to the distance from the viewpoint and the size of the object after perspective transformation as shown in FIGS. .

In FIG. 21, not only the vicinity of the contour ED of the object OB but also the entire OB is subjected to interpolation processing by the bilinear filter, resulting in a blurred image of the entire object OB. Therefore, in the present embodiment, the following technique is employed to solve the problem that the entire object OB becomes a blurred image.

2.8.3 Drawing an Object in the Frame Buffer As in the above-mentioned 2.8.2, the work buffer mapping image shown in FIG. 19 is drawn at the same position on the frame buffer. Specifically, the virtual polygon is drawn on the frame buffer while mapping the mapping image on the work buffer to the virtual polygon.

In this case, FIG. 16 (A) to FIG. 18 (B).
As described above, a virtual polygon (effect area) that contains an object and changes its size according to the size of the object after perspective transformation is generated, and a work buffer is created for the virtual polygon. Map the top mapping image.

Further, in order to prevent the image of the contour line EDL drawn in FIG. 21 from being erased by overwriting, the source α
The test and the destination α test are used together.

That is, as shown in FIG. 24, the texture coordinates are not shifted, and only pixels with α> 0 are passed in the source α test (α test for the mapping image as the writing source), and the destination α test (writing destination) Only α = αJ pixels are passed in the α test for the frame buffer image.

Under the above conditions, the mapping image on the work buffer is directly drawn in the frame buffer without interpolation.

Under the condition, drawing is prohibited for the pixels set to the outline color in the mapping image (work buffer image).

According to the condition, overwriting is prohibited for the pixel region of 0 <α <αJ in which the contour image is drawn in FIG. That is, the contour E of the object OB
A non-blurred object OB on the work buffer only for the area excluding the area of the OB outline EDL (specifically, the right side and lower side EDL) from the inner area of D.
The image is drawn. Thereby, the problem that the entire object OB becomes a blurred image can be solved.

As described above, one feature of this embodiment is that
The α value is made different between the inner region and the outer region of the contour ED of the object OB (FIG. 19), and not only the color but also the α value is interpolated by the bilinear filter, and various discriminations are performed based on the α value after the interpolation. There is in point. That is, based on the α value after interpolation, the region of the contour EDL of the object OB (region where 0 <α <αJ) is determined, or the contour E
A region obtained by removing the region of the contour line EDL from the inner region of D is determined. By doing so, the contour line EDL of the object OB can be generated with a small processing load.

2.9 Drawing Contour Line on Inner Area Next, a method for drawing a contour line on the inner area of the contour of the object will be described.

2.9.1 Generation of Mapping Image First, a mapping image as shown in FIG. 19 is generated by the same method as in 2.8.1 described above.

2.9.2 Generation of α (Mask) Plane Next, only the α (mask) plane in the mapping image on the work buffer shown in FIG. 19 is drawn in the frame buffer.

More specifically, while mapping the mapping image on the work buffer to the virtual polygon, the virtual polygon is drawn on the frame buffer, and only the α plane in the mapping image is drawn on the frame buffer.

As described above, α = αJ (> 0) is set in the inner region of the outline ED of the object OB on the frame buffer, and α = α in the outer region, as shown in FIG.
An α (mask) plane set to αL (= 0) is generated.

2.9.3 Drawing Object Image Next, the object OB image is drawn in the frame buffer. By rendering the object OB image first in the frame buffer in this way, translucent synthesis (α blending) of the object image and the contour image is performed.
Is possible.

More specifically, the virtual polygon is drawn on the frame buffer while mapping the mapping image on the work buffer to the virtual polygon.

Then, in the texture mapping, α is drawn so as not to break the α plane drawn in FIG.
Mask the plane drawing and pass only pixels with α = αJ in the source α test.

As described above, as shown in FIG. 26, the frame buffer stores the object OB image (original image) and FIG.
The α plane generated in 5 is drawn.

2.9.4 Texture Mapping by Bilinear Filter Method Next, the mapping image on the work buffer shown in FIG. 19 is drawn at the same position on the frame buffer.

More specifically, as shown in FIG. 27, while mapping the mapping image on the work buffer to the virtual polygon, the virtual polygon is drawn on the frame buffer.

Also, in this texture mapping, a bilinear filter (texel interpolation) method is selected, and the texture coordinates are set to +, for example, as described in FIG.
Shift (shift) by 0.5 pixels (texels), pass only pixels with α <αJ in the source α test, and pass only pixels with α = αJ in the destination α test.

As a result, an image as shown in FIG. 28 in which the contour line EDL is added to the right side and the lower side of the inner region of the object OB is generated.

That is, in the portion indicated by J1 in FIG. 28, FIG.
As shown in FIG. 9, the color (RJ, GJ, BJ) of the object OB and the color (R
L, GL, and BL) are combined to generate an image of the contour line EDL in the inner region of the contour ED.

In the present embodiment, not only the color but also the α value are subjected to interpolation processing by the bilinear filter. Accordingly, the α value set for the contour line EDL is also an α value obtained by combining αJ of the object OB and αL of the contour line.

The above will be described in more detail as follows.

(I) Pixel whose surrounding pixels to be referred to are all in outline color In the pixel indicated by K1 in FIG. 29, RGB and α values after interpolation are (R, G, B, α) = ( RL, GL, BL, α
L).

At this time, since α = αL = 0 is set (see FIG. 19), the source α test in which only pixels of α <αJ are passed is passed. However, the pixel in the region other than the region where the image of the object OB is drawn is rejected by the destination α test in which only the pixel of α = αJ is passed. Therefore, eventually, pixel drawing as shown by K1 in FIG. 29 is prohibited.

(II) Pixel to which both pixel of outline color and pixel of object color are referenced In the pixel as indicated by K2 in FIG. 29, (R, G, B, α) after interpolation is the above-mentioned 2 The result is the same as the expression (4) shown in .8.2. That is, the color of the pixel after interpolation is the color of the object OB (RJ, GJ, BJ, α
J) and the outline colors (RL, GL, BL, αL) are mixed.

Also, since αJ> 0, 1 ≦ K ≦ 3, and αL = 0, 0 <α <αJ, and the source α test that passes only pixels with α <αJ is passed. Will be rendered in the frame buffer.

Further, by the destination α test in which only the pixel of α = αJ is accepted, only the portion (the right side and the lower side in FIG. 28) in the inner region of the object in the contour image is the frame buffer. Will be drawn.

(III) Pixel in which all surrounding pixels referred to are the object color In the pixel indicated by K3 in FIG. 29, the RGB and α values after interpolation are (R, G, B, α) = (RJ , GJ, BJ, α
J).

At this time, since α = αJ is set (see FIG. 19), the source α test for accepting only pixels of α <αJ is rejected, and drawing is prohibited for these pixels.

As described above, the frame buffer shown in FIG.
8 can be drawn.

2.9.5 Drawing Contour Lines on Left Side and Top Side Next, the mapping image on the work buffer shown in FIG. Map to a virtual object and draw in the frame buffer.

More specifically, as shown in FIG. 30, the bilinear filter method is selected, and the texture coordinates U and V are set to (−0.5, −0.5) opposite to the above-mentioned 2.9.4. ) And shift only pixels with α <αJ in the source α test, and pass only pixels with α = αJ in the destination α test.

Thus, the contour line EDL is also given to the left side and the upper side of the inner area of the object OB, and an image in which the contour line EDL is drawn in the inner area of the contour ED of the object OB is generated as shown in FIG. Will come to be.

3). Processing of this embodiment Next, a detailed example of the processing of this embodiment will be described with reference to the flowcharts of FIGS.

FIG. 32 is a flowchart relating to the generation process of a virtual polygon to be mapped in the mapping image.

First, geometry processing is performed on the object, and the object is subjected to perspective transformation (affine transformation) on the screen (step S1).

Next, based on the coordinates of the vertex of the object after perspective transformation, minimum values XMIN, YMIN, maximum values XMAX, YMAX of the vertexes of the object are obtained (step S2).

Next, the obtained (XMIN, YMI
N), (XMAX, YMAX) based on FIG.
As described in (A) and (B), a virtual polygon having a shape including the image of the object OB is generated (step S3). In this case, the vertexes VVX1 to VV of the virtual polygon
VX4 is as follows.

VVX1 (XMIN, YMIN) VVX2 (XMIN, YMAX) VVX3 (XMAX, YMAX) VVX4 (XMAX, YMIN) Note that the size of the virtual polygon (image effect area) is slightly increased in the vertical and horizontal directions. May be.
More specifically, the minimum values of the X and Y coordinates are set to XMIN and YM.
If IN and the maximum value is XMAX and YMAX,
Subtract 1 pixel from XMIN and YMIN to get XMI
N ′ = XMIN−1 and YMIN ′ = YMIN−1 are obtained, and one pixel is added to XMAX and YMAX to obtain XMAX ′ = XMAX + 1, YMAX ′ = YMAX + 1
Ask for. And these sought (XMIN ',
YMIN '), (XMAX', YMAX '), the vertices VVX1 to VVX4 of the virtual polygon are determined.

FIG. 33 is a flowchart relating to the process of generating a virtual polygon using a simple object as described with reference to FIGS. 18 (A) and 18 (B).

FIG. 33 differs from FIG. 32 in that step S
(XMIN, YMIN) based on the point at which the perspective transformation is performed on the simple object in step 11 and the coordinates of the vertex of the simple object after the perspective transformation in step S12.
(XMAX, YMAX) is obtained, and the other processing is the same.

FIG. 34 is a flowchart relating to processing for adding a contour line to an object.

First, as described with reference to FIG. 19, the work buffer is initialized with contour images (RL, GL, BL, αL) (step S21).

Next, the object whose vertex α value is set to α = αJ (> 0) is perspective-transformed and drawn in the work buffer (step S22). At that time, hidden surface removal is performed using a Z buffer for a work buffer.

Next, as described with reference to FIG. 20, while mapping the mapping image on the work buffer to the virtual polygon by shifting the texture coordinates and using the bilinear filter method, the virtual polygon is drawn on the frame buffer (step S23). ). At that time, α> 0 is designated as the source α test. A pseudo Z value obtained based on object information (for example, vertex coordinates, representative point coordinates, etc.) is set in a virtual polygon, and hidden surface removal is performed using a normal Z buffer.

Next, while mapping the mapping image on the work buffer to the virtual polygon, the virtual polygon is drawn on the frame buffer (step S24).
At that time, α> 0 is specified as the source α test, and α = αJ is specified as the destination α test. Further, a pseudo Z value obtained based on the object information is set in the virtual polygon, and hidden surface removal is performed using a normal Z buffer.

As described above, an image in which a contour line is added to an object (an image in which the contour line is emphasized) can be obtained.

FIG. 35 is a flowchart relating to processing for adding a contour line to the inner area of an object.

First, as described with reference to FIG. 19, the work buffer is initialized with contour images (RL, GL, BL, αL) (step S31).

Next, the object whose vertex α value is set to α = αJ (> 0) is perspective-transformed and drawn in the work buffer (step S32). At that time, a Z test using a normal Z buffer is performed to perform hidden surface removal. In this way, the Z value of the object at the contour drawing position can be set as the Z value of the contour line.

Next, as described with reference to FIG. 25, the mapping image on the work buffer is mapped to the virtual polygon, and only the α value is drawn in the frame buffer (step S33).

Next, as described with reference to FIG. 26, the mapping image on the work buffer is mapped to the virtual polygon, and only the pixel of α = αJ is drawn on the frame buffer (step S34). As a result, the original image of the object is drawn in the frame buffer.

Next, as described with reference to FIG. 27, while mapping the mapping image on the work buffer by mapping the texture coordinates U and V by (0.5, 0.5) to the virtual polygon by the bilinear filter method. The virtual polygon is drawn in the frame buffer (step S3
5). At that time, α <αJ is designated as the source α test. Also, α = αJ as the destination α test
Is specified. Furthermore, the translucent synthesis of the object image and the contour image is performed using the translucency αT set in a given register or the like.

Next, as described in FIG. 30, the mapping image on the work buffer is mapped to the virtual polygon by the bilinear filter method by shifting the texture coordinates U and V by (−0.5, −0.5). Then, the virtual polygon is drawn in the frame buffer (step S
36). At that time, α <αJ is designated as the source α test. Also, α = α as the destination α test
Specify J. Furthermore, the translucent synthesis of the object image and the contour image is performed using the translucency αT set in a given register or the like.

Note that the Z test is not performed in steps S33 to S36 of FIG.

As described above, an image as shown in FIG. 31 in which a contour line is drawn in the inner area of the object can be obtained.

FIG. 36 is a flowchart relating to processing for changing the color of the contour line in accordance with the distance (Z value). Note that the Z value increases as it approaches the viewpoint.

First, ZN and ZF, which are threshold values for the Z value, are used.
(VTN and VTF in FIG. 5A) and the colors CN and CF at the threshold values are set in advance (step S41).

Next, the representative Z value (Z value of the representative point) of the object for drawing the outline is obtained (step S42).

Next, based on the obtained representative Z value, a coefficient V for determining a color is obtained as in the following equation (step S43).

V = (Z-ZF) / (ZN-ZF) where V is V = 1.V when V> 1.0.
When V <0.0, V = 0.0.

Next, based on the obtained coefficient V, the color C of the contour line is obtained as follows (step S44).

C = (CN−CF) × V + CF Next, an outline is drawn using the obtained color C (step S45).

FIG. 37 is a flowchart relating to processing for changing the color of the contour line in accordance with the size (number of pixels) of the object.

First, PN and PF (VT of FIG. 5B) which are threshold values of the size of the object to be drawn.
N, VTF) and the colors CN and CF at the threshold values are preset (step S51).

Next, the number P of pixels (in the 2D image) (the number of vertical pixels × the number of horizontal pixels) on the screen of the object to be drawn is calculated (step S).
52).

Next, a coefficient V for determining a color is obtained as shown in the following equation based on the obtained pixel number P (step S53).

V = (P-PF) / (PN-PF) where V is V = 1.V when V> 1.0.
When V <0.0, V = 0.0.

Next, the color C of the contour line is obtained based on the obtained coefficient V (step S54). Then, a contour line is drawn using the obtained color C (step S55).

FIG. 38 shows the translucency of the contour line as the distance (Z
It is a flowchart regarding the process changed according to (value). FIG. 38 differs from FIG. 36 in the following points.

That is, in step S61, the colors CN, CF
Instead of, semi-transparency αTN, αTF is set.

In step S64, based on the coefficient V, the translucency αT of the contour line is obtained by the following equation.

ΑT = (αTN−αTF) × V + αTF In step S65, a contour line is rendered translucently based on the obtained αT.

FIG. 39 is a flowchart relating to processing for changing the translucency of the contour line in accordance with the size (number of pixels) of the object. FIG. 39 differs from FIG. 37 in the following points.

That is, in step S71, the colors CN, CF
Instead of, semi-transparency αTN, αTF is set.

In step S74, the translucency αT of the contour line is obtained based on the coefficient V as shown in the following equation.

ΑT = (αTN−αTF) × V + αTF In step S75, a contour line is rendered translucently based on the obtained αT.

4. Hardware Configuration Next, an example of a hardware configuration capable of realizing the present embodiment will be described with reference to FIG.

The main processor 900 is a CD 982
It operates based on a program stored in (information storage medium), a program transferred via the communication interface 990, or a program stored in ROM 950 (one of information storage media), game processing, image processing,
Various processes such as sound processing are executed.

The coprocessor 902 assists the processing of the main processor 900, has a product-sum calculator and a divider capable of high-speed parallel calculation, and executes matrix calculation (vector calculation) at high speed. For example, if a physical simulation for moving or moving an object requires processing such as matrix operation, a program operating on the main processor 900 instructs (requests) the processing to the coprocessor 902. )

The geometry processor 904 performs geometry processing such as coordinate transformation, perspective transformation, light source calculation, curved surface generation, etc., and has a product-sum calculator and a divider capable of high-speed parallel computation, and matrix computation (vector (Operation) is executed at high speed. For example, when processing such as coordinate transformation, perspective transformation, and light source calculation is performed, a program operating on the main processor 900 instructs the geometry processor 904 to perform the processing.

The data decompression processor 906 performs a decoding process for decompressing the compressed image data and sound data and a process for accelerating the decoding process of the main processor 900. As a result, a moving image compressed by the MPEG method or the like can be displayed on the opening screen, the intermission screen, the ending screen, or the game screen. Note that image data and sound data to be decoded are stored in ROM 950,
It is stored in the CD 982 or transferred from the outside via the communication interface 990.

The drawing processor 910 executes drawing (rendering) processing of objects composed of primitive surfaces such as polygons and curved surfaces at high speed. When drawing an object, the main processor 900
Uses the function of the DMA controller 970 to pass the object data to the drawing processor 910,
If necessary, the texture is transferred to the texture storage unit 924. Then, the rendering processor 910 renders the object in the frame buffer 922 at high speed while performing hidden surface removal using a Z buffer or the like based on the object data and texture. The drawing processor 910 can also perform α blending (translucent processing), depth cueing, mip mapping, fog processing, bilinear filtering, trilinear filtering, anti-aliasing, shading processing, and the like. When an image for one frame is written in the frame buffer 922, the image is displayed on the display 912.

The sound processor 930 includes a multi-channel ADPCM sound source and the like, and generates high-quality game sounds such as BGM, sound effects, and voices. The generated game sound is output from the speaker 932.

The operation data from the game controller 942, the save data from the memory card 944, and personal data are transferred via the serial interface 940.

A ROM 950 stores system programs and the like. In the case of an arcade game system, the ROM 950 functions as an information storage medium.
Various programs are stored in 950. A hard disk may be used instead of the ROM 950.

The RAM 960 is used as a work area for various processors.

The DMA controller 970 is a DM between the processor and memory (RAM, VRAM, ROM, etc.).
A transfer is controlled.

The CD drive 980 is a CD 982 in which programs, image data, sound data, etc. are stored.
(Information storage medium) is driven to enable access to these programs and data.

The communication interface 990 is an interface for transferring data to and from the outside via a network. In this case, as a network connected to the communication interface 990, a communication line (analog telephone line, ISDN), a high-speed serial bus, or the like can be considered. By using a communication line, data transfer via the Internet becomes possible. Further, by using the high-speed serial bus, data transfer with other game systems becomes possible.

It should be noted that all the means of the present invention may be executed only by hardware, or only by a program stored in an information storage medium or a program distributed via a communication interface. Also good. Alternatively, it may be executed by both hardware and a program.

When each means of the present invention is executed by both hardware and a program, the information storage medium stores a program for executing each means of the present invention using hardware. Will be. More specifically, the program instructs each processor 902, 904, 906, 910, 930, etc., which is hardware, and passes data if necessary. And each processor 902, 904, 906, 910,
930 etc., based on the instruction and the data passed,
Each means of the present invention is executed.

FIG. 41A shows an example in which this embodiment is applied to an arcade game system. The player enjoys the game by operating the lever 1102, the button 1104, and the like while viewing the game image displayed on the display 1100. Various processors and various memories are mounted on the built-in system board (circuit board) 1106. Information (program or data) for executing each means of the present invention is stored in a memory 1108 which is an information storage medium on the system board 1106. Hereinafter, this information is referred to as storage information.

FIG. 41B shows an example in which the present embodiment is applied to a home game system. The player enjoys the game by operating the game controllers 1202 and 1204 while viewing the game image displayed on the display 1200. In this case, the stored information is stored in the CD 1206, which is an information storage medium that is detachable from the main system, or in the memory cards 1208, 1209, and the like.

FIG. 41C shows a host device 1300,
The host device 1300 and the network 1302 (LA
Terminal 130 connected via a small network such as N or a wide area network such as the Internet.
An example in which the present embodiment is applied to a system including 4-1 to 1304-n will be described. In this case, the storage information is, for example, a magnetic disk device that can be controlled by the host device 1300,
It is stored in an information storage medium 1306 such as a magnetic tape device or memory. When the terminals 1304-1 to 1304-n are capable of generating game images and game sounds stand-alone, the host device 1300 receives game images,
A game program or the like for generating game sounds is provided on the terminal
Delivered to 304-1 to 1304-n. On the other hand, if it cannot be generated stand-alone, the host device 1300 generates a game image and a game sound, which are generated by the terminals 1304-1 to 1304-1.
1304-n and output at the terminal.

In the case of the configuration shown in FIG. 41C, each means of the present invention may be executed in a distributed manner between the host device (server) and the terminal. The storage information for executing each means of the present invention may be distributed and stored in the information storage medium of the host device (server) and the information storage medium of the terminal.

The terminal connected to the network may be a home game system or an arcade game system. When the arcade game system is connected to a network, the save information storage device can exchange information with the arcade game system and exchange information with the home game system. It is desirable to use (memory card, portable game device).

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

For example, in the invention according to the dependent claims of the present invention, a part of the constituent features of the dependent claims can be omitted. Moreover, the principal part of the invention according to one independent claim of the present invention can be made dependent on another independent claim.

Further, as parameters for changing the image of the outline of the object, the distance from the viewpoint and the size of the object after the perspective transformation are particularly desirable. However, the present invention is also applicable when parameters equivalent to these are used. Included in the range.

Further, in this embodiment, with the aim of preventing the situation where the contour image of the object is unnecessarily conspicuous, the contour image depends on the distance from the viewpoint and the size of the object after the perspective transformation. The case of changing is mainly described.

However, conversely, the contour image may be changed according to the distance from the viewpoint or the size of the object after perspective transformation, aiming at a video effect that makes the contour image of the object stand out. . For example, in a certain distance range, as the distance from the viewpoint is farther (the smaller the size of the object after perspective transformation), the contour line becomes opaque, or the color of the contour line has been described in this embodiment. It is also possible to make it approach a color different from CF (second color).

As a method for drawing the outline of an object, a method using texture mapping of the texel interpolation method is particularly desirable, but is not limited to this. For example, the outline of the object may be drawn by a method as shown in FIGS. 42 (A) to 42 (F).

That is, in this method, first, FIG.
As shown in (A) and (B), for example, an outline image 420 (an image painted in the outline color) is applied to the drawing area 410 of the original image on the drawing area 400 (frame buffer or the like). Draw a few pixels upwards. Similarly, as shown in FIGS. 42 (C), (D), and (E), an outline image 420 is displayed on the drawing planned area 410,
Draw a few pixels down, right, or left. Finally, as shown in FIG. 42F, the original image 430 is drawn in the drawing scheduled area 410.

This method has the advantage that the processing load on the CPU performing 3D (three-dimensional) processing can be reduced, although the processing load on the drawing processor becomes heavy because the contour line can be drawn only by 2D processing.

[0296] Various modifications can be made to the function characteristics of the distance from the viewpoint, the size of the object after perspective transformation, the color of the outline, and the translucency. For example, FIG.
(A), (B), a linear characteristic as shown in FIGS. 7A and 7B, and a curved characteristic using a multidimensional function may be used. That is, for example, (VTN, CN) and (VTF, C
F), or (VTN, αTN) and (VTF, αT).
F) may be interpolated with a multidimensional function instead of linear interpolation.

As shown in FIGS. 43A and 43B, four or more threshold values may be provided, and the number of threshold values is arbitrary. Alternatively, it is possible not to provide a threshold value. 43 (A) and 43 (B), when the distance from the viewpoint and the size of the object after perspective transformation are in the range of VTN2 to VTN3, FIG.
As described in (A), the color and semi-transparency of the outline may be kept substantially constant.

The object for generating the contour image is not necessarily displayed. For example, the case where the object is not displayed and only the contour image is displayed is also included in the scope of the present invention. In this way, it becomes possible to generate a three-dimensional image such as a character drawn only by a contour line, and an unprecedented video effect can be generated.

Further, as texture mapping of the texel interpolation method, texture mapping of the bilinear filter method is particularly desirable, but is not limited to this.

Also, the generation method of the virtual polygon is shown in FIG.
Although the method described with reference to FIGS. 18A to 18B is particularly desirable, the present invention is not limited to this, and various modifications can be made.

Further, it is particularly desirable to discriminate the outline region of the object based on the α value subjected to texel interpolation, but the present invention is not limited to this, and various modifications can be made.

The present invention can be applied to various games (such as fighting games, shooting games, robot battle games, sports games, competitive games, role playing games, music playing games, dance games, etc.).

The present invention also provides various game systems (image generation such as a business game system, a home game system, a large attraction system in which a large number of players participate, a simulator, a multimedia terminal, and a system board for generating game images. System).

[Brief description of the drawings]

FIG. 1 is an example of a functional block diagram of a game system according to an embodiment.

FIG. 2 is an example of a game image generated according to the present embodiment.

FIG. 3 is a diagram for explaining a problem that an outline of an object is unnecessarily noticeable when the distance from the viewpoint is long (when the size of the object after perspective transformation is small); is there.

FIG. 4 is a diagram for explaining a technique for changing the color of an outline according to the distance from a viewpoint and the size of an object after perspective transformation.

FIG. 5A is an example of a function characteristic of the distance from the viewpoint and the color of the outline, and FIG. 5B is a graph showing the size of the object and the color of the outline after perspective transformation. It is an example of a function characteristic.

FIG. 6 is a diagram for explaining a method of changing the translucency of the contour line according to the distance from the viewpoint and the size of the object after perspective transformation.

FIG. 7A is an example of functional characteristics of the distance from the viewpoint and the translucency of the outline, and FIG. 7B is an illustration showing the size of the object and the translucency of the outline after the perspective transformation. It is an example of a function characteristic.

FIGS. 8A and 8B are diagrams for explaining a method of setting a threshold value VTN.

FIGS. 9A and 9B are diagrams for explaining problems of a method for controlling the color of a contour line. FIG.

FIGS. 10A and 10B are diagrams for explaining a method of drawing a contour line in an outer region or an inner region of the contour of an object.

FIGS. 11A and 11B are diagrams for explaining a problem when a contour line is drawn in an outer region of the contour of an object.

FIG. 12 is a diagram for describing bilinear filter type texture mapping;

FIGS. 13A and 13B are diagrams illustrating an example of a mapping image and an example of an image obtained by mapping the mapping image to a virtual polygon.

FIG. 14 is a diagram for explaining a method of generating a contour image by effectively using bilinear filter type texture mapping.

FIG. 15 is a diagram for explaining the principle of a phenomenon in which the color of each pixel oozes out by the bilinear filter type interpolation function;

FIGS. 16A and 16B are diagrams for explaining a generation method of virtual polygons.

FIGS. 17A and 17B are diagrams for describing a method of generating a virtual polygon based on the coordinates of the vertex of an object after perspective transformation.

18A and 18B are diagrams for explaining a method of generating a virtual polygon based on the coordinates of the vertex of a simple object after perspective transformation.

FIG. 19 is a diagram for illustrating an example of a mapping image generated on a work buffer.

FIG. 20 is a diagram for describing a technique of mapping a mapping image to a virtual polygon while shifting texture coordinates by a bilinear filter method and drawing it in a frame buffer.

FIG. 21 is a diagram illustrating an example of an image generated on the frame buffer by the method of FIG. 20;

FIG. 22 shows pixel R by bilinear filter method.
It is a figure for demonstrating the method of interpolating GB and alpha value.

FIGS. 23A and 23B are diagrams for describing a method for generating an image of an outline of an object.

FIG. 24 is a diagram for describing a technique for eliminating the entire object from becoming a blurred image.

FIG. 25 is a diagram for illustrating an example of an α plane generated on a frame buffer.

FIG. 26 is a diagram for illustrating an example of an original image and an α plane of an object generated on the frame buffer.

FIG. 27 is a diagram for explaining a technique of mapping a mapping image to a virtual polygon while drawing the texture image by shifting the texture coordinates by +0.5 pixels by the bilinear filter method, and drawing it in the frame buffer.

28 is a diagram showing an example of an image generated on a frame buffer by the method of FIG. 27. FIG.

FIG. 29 is a diagram for describing a method for generating an image of an outline of an object.

FIG. 30 is a diagram for describing a technique of mapping a mapping image to a virtual polygon while drawing texture coordinates by shifting the texture coordinates by −0.5 pixels by a bilinear filter method, and drawing the frame image on a frame buffer;

FIG. 31 is a diagram showing an example of a final image generated on the frame buffer by the method of FIG. 30;

FIG. 32 is a flowchart showing a detailed example of processing of the present embodiment.

FIG. 33 is a flowchart illustrating a detailed example of processing of the present embodiment.

FIG. 34 is a flowchart showing a detailed example of processing of the present embodiment.

FIG. 35 is a flowchart showing a detailed example of processing of the present embodiment.

FIG. 36 is a flowchart showing a detailed example of processing of the present embodiment.

FIG. 37 is a flowchart showing a detailed example of processing of the present embodiment.

FIG. 38 is a flowchart illustrating a detailed example of processing of the present embodiment.

FIG. 39 is a flowchart showing a detailed example of processing of the present embodiment.

FIG. 40 is a diagram illustrating an example of a hardware configuration capable of realizing the present embodiment.

41 (A), (B), and (C) are diagrams showing examples of various forms of systems to which this embodiment is applied.

FIGS. 42A to 42F are diagrams for explaining another method of drawing a contour line.

FIGS. 43A and 43B are diagrams illustrating other examples of the functional characteristics of the distance from the viewpoint, the size of the object after perspective transformation, the color of the contour line, and the translucency.

[Explanation of symbols]

OB object SOB simple object VPL virtual polygon (virtual object) ED contour EDL outline VX1 to VX6 vertex VVX1 to VVX4 vertex VSX1 to VSX8 vertex 100 processor 110 Geometry processing unit 112 Virtual object generator 114 Contour line image changing unit 120 Drawing part (Object / Outline drawing part) 122 Mapping image generation unit 130 Texture mapping section 132 Synthesizer 134 Hidden surface removal part 160 Operation unit 170 Storage unit 172 Main memory 174 Drawing area 176 texture storage 180 Information storage medium 190 Display 192 sound output section 194 Portable information storage device 196 Communication Department

Claims (29)

(57) [Claims] 1. A game system for generating an image, comprising: means for drawing an image of an object outline; means for changing an image of an object outline according to a distance from a viewpoint; of and means for generating an image at a given viewpoint, as the distance from the view point is far, the color of the contour line of the object
A game system characterized by bringing a second color closer to a given second color . 2. The outline color of an object according to claim 1, wherein the distance from the viewpoint is near the distance when the viewpoint follows the object while keeping the distance to the object substantially constant. A game system characterized by maintaining a substantially constant value. 3. The object according to claim 1, wherein the color of the outline of the object is set to the second color when the distance from the viewpoint is longer than a given threshold value. A game system. 4. A game system for generating an image, comprising: means for drawing an image of an object outline; means for changing an image of an object outline according to a distance from a viewpoint; of and means for generating an image at a given viewpoint, as the distance from the view point is far, image of the contour line of the object
A game system characterized by making the image more transparent . 5. The method according to claim 4, wherein when the distance from the viewpoint is near the distance when the viewpoint follows the object while keeping the distance to the object substantially constant, A game system characterized in that the transparency is kept substantially constant. 6. The game system according to claim 4, wherein the image of the outline of the object is substantially invisible when the distance from the viewpoint is longer than a given threshold value. 7. A game system for generating an image, comprising: means for drawing an image of an object outline; and means for changing the image of an object outline according to the size of the object after perspective transformation; , and means for generating an image at a given viewpoint in the object space, the smaller the size of the object after perspective transformation, of
A game system characterized in that the color of a contour line of a project is brought close to a given second color . 8. The method according to claim 7, wherein the size of the object after the perspective transformation is around the size of the object when the viewpoint follows the object while keeping the distance to the object substantially constant. A game system characterized in that the color of the outline of an object is kept substantially constant. 9. The method of claim 7 or 8, when the size of the object after perspective transformation becomes less than a given threshold, the color of the contour line of the object is set to the second color A game system characterized by that. 10. A game system for image generation, comprising: means for drawing an image of an object outline; and means for changing the image of an object outline according to the size of the object after perspective transformation. , and means for generating an image at a given viewpoint in the object space, the smaller the size of the object after perspective transformation, of
A game system characterized by making the image of the outline of a project more transparent . 11. The method according to claim 10, wherein the size of the object after the perspective transformation is around the size of the object when the viewpoint follows the object while keeping the distance to the object substantially constant. A game system characterized in that the translucency of the outline of an object is kept substantially constant. 12. The method according to claim 10, wherein the image of the outline of the object is substantially invisible when the size of the object after the perspective transformation becomes smaller than a given threshold value. Game system to play. 13. The game system according to claim 1, wherein an image of the outline of the object is drawn in an outer region of the outline of the object. 14. The game system according to claim 4, wherein an image of an outline of an object is drawn in an inner area of the outline of the object. 15. A computer-useable program comprising: means for drawing an image of an object outline; means for changing an image of an object outline according to a distance from a viewpoint; as a means for generating an image at a given point of view, cause the computer to function, as the distance from the viewpoint is far, the color of the contour line of the object
A program characterized by approaching a given second color . 16. The outline color of an object according to claim 15, wherein the distance from the viewpoint is near the distance when the viewpoint follows the object while keeping the distance to the object substantially constant. A program characterized in that is kept substantially constant. 17. The object according to claim 15, wherein the color of the outline of the object is set to the second color when the distance from the viewpoint is larger than a given threshold value. Program. 18. A program usable by a computer, comprising: means for drawing an image of an object outline; means for changing an image of an object outline according to a distance from a viewpoint; a given image as a means for generating a perspective causes a computer to function longer the distance from the viewpoint, image of the contour line of the object
A program characterized by making images more transparent . 19. The outline of an object according to claim 18, wherein the distance from the viewpoint is near the distance when the viewpoint follows the object while keeping the distance to the object substantially constant. A program characterized in that the transparency is kept substantially constant. 20. The program according to claim 18, wherein the image of the outline of the object is substantially invisible when the distance from the viewpoint is longer than a given threshold value. 21. A program usable by a computer, comprising: means for drawing an image of an outline of an object; and means for changing the image of the outline of an object according to the size of the object after perspective transformation. , as a means for generating an image at a given viewpoint in the object space, cause the computer to function, the smaller the size of the object after perspective transformation, of
A program characterized by bringing the color of the outline of a project closer to a given second color . 22. The method according to claim 21, wherein the size of the object after the perspective transformation is around the size of the object when the viewpoint follows the object while keeping the distance to the object substantially constant. A program characterized in that the color of the outline of an object is kept substantially constant. 23. The outline color of an object according to claim 21, wherein the color of the outline of the object is set to the second color when the size of the object after the perspective transformation becomes smaller than a given threshold value. A program characterized by that. 24. A program usable by a computer, said means for drawing an image of an object outline, and means for changing an image of an object outline according to the size of the object after perspective transformation , as a means for generating an image at a given viewpoint in the object space, cause the computer to function, the smaller the size of the object after perspective transformation, of
A program characterized by making the image of the outline of a project more transparent . 25. The method according to claim 24, wherein the size of the object after the perspective transformation is close to the size of the object when the viewpoint follows the object while keeping the distance to the object substantially constant. The program is characterized in that the translucency of the outline of the object is kept substantially constant. 26. The image of the outline of an object according to claim 24 or 25, wherein the image of the outline of the object is substantially invisible when the size of the object after the perspective transformation becomes smaller than a given threshold value. Program to do. 27. The program according to claim 15, wherein an image of an object outline is drawn in a region outside the object outline. 28. The program according to claim 18, wherein an image of an object outline is drawn in an inner area of the object outline. 29. An information storage medium usable by a computer, comprising the program according to any one of claims 15 to 28 .