JP3538393B2 - 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. (1) For example, assume that a contour line having a thickness of 1 pixel is drawn on the outer periphery of an object. In such a case, when the distance between the viewpoint and the object is short (when the object is large relative to the pixel on the screen)
Does not have much of a problem. However, when the distance between the viewpoint and the object is far (when the size of the object with respect to the pixel on the screen is small), the relative thickness of the contour line with respect to the size of the object becomes thicker than necessary. An unnatural image is generated. (2) If the drawing order between the contour line and another object is inappropriate, or if an inappropriate Z value (depth value) is given to the contour line, it is inappropriate between the contour line and the other object. Hidden surface removal and translucent composition are performed, and an unnatural image is generated.

The present invention has been made in view of the above problems, and an object thereof is to provide a game system, a program, and an information storage medium capable of efficiently generating a more natural contour image. There is to do.

[0009]

In order to solve the above-mentioned problems, the present invention provides a game system for generating an image, wherein an image of an outline of an object generated based on the image of the object And means for drawing in an inner region of the contour, 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 image of the outline of an object is generated based on the image of the object (for example, an image drawn in a drawing area, a two-dimensional image after perspective transformation, etc.). Then, the image of the contour line is drawn in the inner area of the contour of the object. In this way, it is possible to perform a composition process (translucent composition, α composition, etc.) between the object image and the contour image. Also, the object Z
It becomes easy to set the value as the Z value of the contour line, and appropriate hidden surface removal or the like can be realized. As a result, a more natural contour image can be efficiently generated.

It should be noted that the object for drawing the outline may be the entire model object, or may be a part object (sub-object) constituting the model object. Further, as a method for drawing the outline of the object, a method of shifting the texture coordinates by the texel interpolation method is particularly desirable, but is not limited thereto.

In addition, the game system, information storage medium and program according to the present invention provide an object image and an object outline image with translucency determined according to the distance from the viewpoint or the size of the object after perspective transformation. It is characterized by semi-transparent composition. In this way, for example, the process of making the object outline more transparent as the distance from the viewpoint increases, or the process of making the object outline more transparent as the size of the object after perspective transformation becomes smaller It becomes possible. As a result, it is possible to solve the problem that the relative thickness of the outline of the object becomes conspicuous.

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.
As for the size of the object, consider the total number of pixels of the object (vertical pixel number × horizontal pixel number), vertical pixel number, horizontal pixel number, or various parameters equivalent to these pixel numbers. Can do.

Also, a virtual object that includes the image of the object after perspective transformation and that changes in size according to the size of the object after perspective transformation is generated, and 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 Z value of the object at the position where the contour line is drawn is set as the Z value of the contour line. 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.

In the game system, information storage medium and program according to the present invention, the mapping is such that 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. An image is generated, and the generated mapping image is texture-mapped to a virtual object by a texel interpolation method while shifting texture coordinates in the first shift direction, and then the mapping image is shifted to the texture coordinates by a second. An image of the outline of the object is generated by texture mapping to the virtual object by the texel interpolation method while shifting in the direction. By doing this, the outline of the object is drawn by a simple process of mapping the generated mapping image to the virtual object by the texel interpolation method while shifting the texture coordinates in the first or second shift direction. become able to. Therefore, it is possible to generate a game image that can appeal to the feeling of a person who likes manga and anime with a small drawing processing load.

The texel interpolation method is not particularly limited, but is a method of interpolating texel image information to obtain pixel image information. For example, a bilinear filter method or a trilinear filter method is considered. be able to.

The virtual object is preferably a primitive surface such as a polygon, but may be a three-dimensional object. The virtual object is preferably not displayed on the screen, but may be displayed.

In the game system, information storage medium, and program according to the present invention, the mapping image is generated by drawing an object after perspective transformation in a drawing area in which outline color information is set as a background. It is characterized by that. In this way, it is possible to generate a mapping image by a simple process of setting outline color information on the background and drawing the perspective-transformed object in the drawing area.

In the game system, information storage medium, and program according to the present invention, the virtual object includes all or part of the image of the object after perspective transformation, and the virtual object corresponds to the size of the object after perspective transformation. It is an object whose size changes. In this way, when the area occupied by the object in the screen changes, the size of the virtual object changes accordingly. Accordingly, it is possible to perform the drawing process within the optimum range according to the size of the object after the perspective transformation, and the drawing process can be made more efficient.

The game system, information storage medium, and program according to the present invention are characterized in that the virtual object is generated based on the coordinates of the definition point of the object after perspective transformation. In this way, it is only necessary to obtain, for example, the maximum and minimum coordinates of the definition points (control points, vertices, etc.) of the object after perspective transformation, and the size of the object depends on the size of the object after perspective transformation. It becomes possible to generate a virtual object that changes. Since the size of the virtual object can be optimally reduced according to the size of the object after the perspective transformation, the load of the drawing process can be reduced.

In the game system, information storage medium, and program according to the present invention, when a simple object is set for an object, the virtual object is stored on the basis of the coordinates of the definition point of the simple object after perspective transformation. It is generated. In this way, it is only necessary to obtain the maximum and minimum coordinates of the definition points (control points, vertices, etc.) of the simple object after the perspective transformation, and the size of the object depends on the size of the object after the perspective transformation. It becomes possible to generate a virtual object whose length changes. Since the processing target for obtaining the maximum value, the minimum value, etc. is the coordinates of the vertices of the simple object having a small number of vertices, there is an advantage that the processing load can be reduced.

Also, the game system, information storage medium and program according to the present invention make the texel interpolation different from the α value set in the inner area of the object outline and the α value set in the outer area of the object outline. On the basis of the α value thus determined, a contour region in the inner region of the contour of the object is discriminated. In this way, when mapping the mapping image to the virtual object by the texel interpolation method, the α value for determining the contour region in the inner region of the contour of the object is also generated at the same time. Efficiency.

The game system, information storage medium, and program according to the present invention draw an object in the drawing area and then draw an image of the contour line in the inner area of the outline of the object drawn in the drawing area. Features. By managing the drawing order in this way, it is possible to perform appropriate synthesis processing (semi-transparent synthesis, etc.) between the object image and the contour image.

[0025]

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 the figure, the present embodiment only needs to include at least the processing unit 100 (or include the processing unit 100 and the storage unit 170).
Other blocks can be optional components.

The operation unit 160 is used by 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 according to 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 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) includes 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, 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 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 kinds 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 generation unit 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, 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) , Processing for determining the drawing order). Alternatively, depending on the distance from the viewpoint and the size of the object after the perspective transformation, the color of the contour line is given by the given second
The process (such as a process for setting the second color) is performed to bring the color closer to the first color.

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), A drawing process is performed so that the image is drawn in the inner area of the object outline. In this way, the process of translucently combining the object image and the contour line image, the process of setting the Z value of the object at the contour drawing position as the Z value of the contour line, etc. can be easily realized. become able to.

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 a process 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 mask synthesizing processing and translucent processing 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, the Z value of the object at the contour drawing position is written in this Z buffer, and the hidden surface removal of the contour line is performed based on the written Z value. In addition,
The hidden surface may be deleted by sorting the primitive surfaces according to the distance from the viewpoint and drawing the primitive surfaces in order from the viewpoint, such as a depth sort method (Z sort method).

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 the Present Embodiment 2.1 Outline Drawing on the Inner Area of an Object FIG. 2 shows an example of a game image generated by the game system of the present 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.

In this embodiment, as shown in FIG. 3, the image of the OB outline EDL obtained by performing 2D (two-dimensional) processing on the image of the object OB is the OB outline ED. The drawing process is performed so that the image is drawn in the inner area.

In this way, a process of translucently combining the OB image and the contour EDL image with a translucency determined according to the distance from the viewpoint and the size of the object OB after perspective transformation, Object O at the line drawing position
A process of setting the Z value of B as the Z value of the contour line EDL is possible.

For example, as a method for drawing a contour line as shown in FIG. 2, a comparative example described below can be considered.

In this comparative example, as shown in FIGS. 4A and 4B, the contour line image 420 with respect to the drawing area 410 of the original image on the drawing area 400 (frame buffer or the like).
For example, the image drawn with the outline color is shifted by several pixels in the upward direction. Similarly, FIG.
As shown in (C), (D), and (E), the drawing scheduled area 4
The contour image 420 is drawn with respect to 10 shifted by several pixels in the downward direction, the right direction, and the left direction. Finally, as shown in FIG. 4F, the original image 430 is drawn in the drawing scheduled area 410.

According to this comparative example, the contour line can be drawn only by 2D processing. Therefore, although the processing load on the drawing processor increases, there is an advantage that the processing load on the CPU performing 3D (three-dimensional) processing can be reduced. .

However, in this comparative example, FIG.
As is clear from (F), contour lines (422, 424, 426, 4 and 4) are formed in the outer region of the contour of the object (430).
28) is drawn.

Accordingly, in this comparative example, it becomes impossible to perform the semitransparent composition of the object image and the contour image. For this reason, it becomes difficult to solve the later-described problem that the relative thickness of the contour line is unnecessarily conspicuous when the distance from the viewpoint is long, using a semi-transparent composition method.

In this comparative example, since a contour line is drawn in the outer region, it is difficult to set the Z value of the object at the contour drawing position as the Z value of the contour line. Therefore, problems such as inappropriate hidden surface removal and semi-transparent composition being performed between the contour line and another object (background, etc.), and an unnatural image are generated.

On the other hand, in this embodiment, since the image of the contour line EDL is drawn in the inner area of the object OB as shown in FIG. 3, the problems of the comparative example as described above can be easily solved. .

2.2 Contour Translucency Change Processing In a three-dimensional game, the player's viewpoint (virtual camera) moves to an arbitrary position in accordance with the player's operation input and the like to represent a character or the like. The object 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 problems occur.

That is, as shown by A1 in FIG. 5, when the distance between the viewpoint and the object OB is short (when the area occupied by the object on the screen is large), the outline EDL of the object OB is not so thick. It does not stand out and does not look like an unnatural image.

However, as shown by A2 and A3 in FIG. 5, when the distance from the viewpoint is increased (when the area occupied by 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 object image and the image of the outline of the object are determined with translucency (equivalent to transparency and opacity) determined according to the distance from the viewpoint and the size of the object after perspective transformation. Translucent synthesis (α synthesis) is performed.

That is, as indicated by C1 and C2 in FIG. 6, as the distance from the viewpoint increases (the size of the object after perspective transformation decreases), the object O
The contour line ED is changed by changing the translucency of the contour line EDL of B.
Make L 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. 5 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. 5 and C3 in FIG. 6, 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 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.

In particular, the method shown in FIG. 6 is effective when the contour line EDL is drawn in the inner region of the contour ED of the object OB as shown in FIG.

That is, when a contour line is drawn in the outer region of the contour as shown in FIG. 4 (F), between the contour line and another object (an object other than the object on which the contour line is drawn). So translucent synthesis is performed. Accordingly, Z sorting between the contour line and other objects becomes necessary, and the processing becomes complicated. Further, an unnatural image may be generated by semi-transparent composition of the contour line and other objects.

On the other hand, when the outline is drawn in the inner area of the outline as shown in FIG. 6, the object is drawn first and then the outline is drawn. Allows translucent composition of objects and contours. Therefore, management of the drawing order is simplified and
The contour line and other objects are not translucently synthesized, 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 is αT
For example, the outline of the object becomes completely transparent (not visible) as indicated by C3 in FIG.

The distance from the viewpoint in FIG. 7A is particularly preferably the depth distance (Z value) of the object (representative point of the object) from the viewpoint of reducing the processing load. It is not limited. 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 FIG. 7B is the total number of pixels of the object (vertical pixel number × horizontal pixel number) 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.

As shown in FIG. 8A, in this type of three-dimensional game, when the object OB moves, the distance between the object OB and the viewpoint VP (virtual camera) is substantially constant. While keeping the distance ZVB, VP
There are many scenes in which OB follows OB.

In such a scene, if the translucency of the contour line changes frequently according to the distance from the viewpoint and the size of the object as shown in FIG. 6, an image that looks unnatural to the player is generated. The problem that is done arises.

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. Try to keep the translucency of the lines approximately constant. Or the object O after perspective transformation
When the size of B is in the vicinity of the size of OB in the follow-up movement mode (size at the distance ZVB), the translucency of the outline of the OB is kept substantially constant. More specifically, the threshold value 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). In this way, as is apparent from the function characteristics of FIGS. 7A and 7B, the translucency of the contour line does not change during the follow movement mode. As a result, the viewpoint VP O
The above problem that an unnatural image is generated in the follow-up movement mode to B can be solved.

Then, when some event occurs and 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), FIG. As shown, the translucency of the outline is the distance from the viewpoint VP (OB
It will change according to the size). This
The occurrence of the above event can also solve the problem that the distance between the viewpoint and the object is increased, and the relative thickness of the contour line is unnecessarily noticeable.

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

That is, when the size of the object OB is reduced as indicated by A3 in FIG. 5, if the outline EDL is not completely transparent, it appears as if the OB is filled with the EDL color. An unnatural image is generated.

Therefore, the size of the object OB is as shown in FIG.
The threshold value VTF is set to a value such that the contour line EDL becomes completely transparent when the size is as indicated by A3. In this way, when the size of the object OB is as shown in A3 in FIG. 5, the contour line EDL becomes invisible as shown in C3 in FIG.
A situation where an unnatural image as shown in A3 of FIG.

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

2.3 Setting the Z Value of the Outline In this embodiment, the Z value of the object at the position where the outline is drawn is set as the Z value of the outline.

Specifically, as shown in FIG. 9, the Z value at the contour drawing positions PE1 and PE2 is set as the Z value of the contour EDL. More specifically, when the object OB is drawn in the drawing area (work buffer, frame buffer), the Z values at the contour drawing positions PE1 and PE2 are written in the Z buffer.
The value is used as the Z value of the contour line EDL.

In this way, it is possible to properly delete the hidden surface between the contour line EDL and other objects.
In this embodiment, the Z value at the contour drawing positions PE1 and PE2 can be set as the Z value of the contour EDL as shown in FIG.
This is because the outline EDL is drawn in the inner area of D.

For example, as shown in FIG. 4 (F), when a contour line is drawn in the outer region of the contour of the object, it is difficult to give an appropriate Z value to the contour line. If an appropriate Z value is not given to the contour line, FIG.
As shown in 0 (A), the hidden surface removal is not performed accurately, and the contour line EDL becomes another object OB such as a background.
Problems such as hiding in 2 and disappearing occur.

Further, when a contour line is drawn in the outer region of the contour of the object, when the semi-transparent composition processing of the contour line EDL as shown in FIG. 6 is performed, the contour as shown in FIG. Translucent composition of line EDL and other object OB2 will be performed. As a result, E1 in FIG.
The color of the contour line EDL is different between the part shown in E2 and the part shown in E2, and an unnatural image is generated.

If a contour line is drawn in the inner region of the contour of the object as in this embodiment, and the Z value at the contour drawing position is set as the Z value of the contour line, as shown in FIG.
Hidden surface erasure is accurately performed, and the problem that the outline EDL is hidden behind other objects OB2 and cannot be seen can be prevented. In addition, as long as the drawing order of drawing the contour line EDL after the drawing of the object OB is observed, it is possible to ensure that the semi-transparent composition is performed between the object OB and the contour line EDL. Therefore, the outline ED
It is possible to prevent a problem as shown in FIG. 10B that the translucent composition processing is performed between L and another object OB2.

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

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 contour line 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 to 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.

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.

Further, according to the method of this 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.

CP44 = (C44 + C45 + C54 + C55) / 4 (2) Therefore, when bilinear filter type texture mapping is performed while the texture coordinates are shifted in the lower right direction, the color C44 of the texel T44, as shown in FIG.
That is, the original color of the pixel P44 is the pixels P33, P3.
4, P43 and P44 ooze by 1/4. As a result, an image of the contour line EDL as shown in FIG. 13B in which the contour line color and the object color are mixed can be generated.

2.5 Generation of Virtual Polygons Various shapes of virtual polygons to be mapped in the mapping image in FIG. 14 can be used.

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

However, it has been found that when 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-size 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 of the object 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, and 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 this 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).

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

Further, as described with reference to FIGS. 6 and 7B, when the translucency of the contour line is changed in accordance with the size of the object after the perspective transformation, FIGS.
The size (number of pixels) of the virtual polygon (virtual object) generated by the method 8 (B) may be obtained, and the translucency of the contour line may be changed based on the size.

2.6 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 2.4 above.

2.6.1 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 on 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).

By doing so, an image (mapping image) as shown in FIG. 19 is drawn in the work buffer.

That is, the inner area of the outline ED of the object OB is set to the color of OB (RJ, GJ, BJ), and the outer area of the outline ED is set to the color of the outline (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.

2.6.2 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 a virtual polygon (virtual object in a broad sense; VPL in FIGS. 16A to 18B), the virtual polygon is mapped to the frame buffer. And only the α plane in the mapping image is drawn in the frame buffer.

As described above, α = αJ (> 0) is set in the inner region of the contour 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.

2.6.3 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.

In this 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. 21, the frame buffer stores the object OB image (original image) and FIG.
The α plane generated at 0 is drawn.

2.6.4 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. 22, the mapping image on the work buffer is represented by a virtual polygon (FIG. 16).
While mapping to (A) to FIG. 18 (B)), the virtual polygon is drawn in the frame buffer.

In addition, when this texture mapping is performed, a bilinear filter (texel interpolation) method is selected, and the texture coordinates are set to, for example, + as described in FIG.
Shift by 0.5 pixels (texels), pass only α <αJ pixels in the source α test (α test for the mapping image that is the writing source), and the destination α test (the frame buffer that is the writing destination) In the α test for the image of (2), only pixels with α = αJ are accepted.

As a result, an image as shown in FIG. 23 in which the contour line EDL is given to the right side and the lower side of the inner area of 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 to 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. 24, 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.

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 obtained by interpolation. Color and α value (color and α value of pixel A after interpolation). Also, (RA, GA, BA, αA), (RB, G
B, BB, αB), (RC, GC, BC, αC) (R
D, 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,
The RGB values of C and D ooze out from the pixel A by 1/4 each. Therefore, in the part indicated by J1 in FIG.
As shown in FIG. 5, 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.

It should be noted 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.

In this 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 in which all the surrounding pixels referred to are in outline color In the pixel indicated by K1 in FIG. 25, the RGB and α values of the surrounding pixels (texels) to be referenced are all (RL, G
L, BL, αL). Therefore, in the above equation (3), (RA, GA, BA, αA) = (RB, GB, B
B, αB) = (RC, GC, BC, αC) = (RD, G
D, BD, αD) = (RL, GL, BL, αL), so that the RGB and α values after interpolation are (R, G, B, α) =
(RL, GL, BL, αL).

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. Accordingly, drawing of pixels as indicated by K1 in FIG. 25 is eventually prohibited.

(II) Pixels to which both outline color pixels and object color pixels are referenced Pixels as indicated by K2 in FIG.
Pixels (texels) of (RL, GL, BL, αL) and pixels (texels) of (RJ, GJ, BJ, αJ) are mixed. In this case, assuming that the number of pixels (RJ, GJ, BJ, αJ) is K, (R, G, B, α) after interpolation according to the above equation (3) is represented by the following equation.

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, αJ) and the contour line. The color (RL, GL, BL, αL) is 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.

Also, 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 contours in FIG. 23) in the inner region of the object in the contour image is the frame buffer. Will be drawn.

(III) Pixel in which all the surrounding pixels referred to are the object color In the pixel indicated by K3 in FIG. 25, the RGB and α values of the surrounding pixels (texels) to be referenced are all (RJ, G
J, BJ, αJ). Therefore, in the above equation (3), (RA, GA, BA, αA) = (RB, GB, B
B, αB) = (RC, GC, BC, αC) = (RD, G
D, BD, αD) = (RJ, GJ, BJ, αJ), so that the RGB and α values after interpolation are (R, G, B, α) =
(RJ, GJ, BJ, αJ).

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.
3 can be drawn.

2.6.5 Drawing Contour Lines on Left Side and Top Side Next, the mapping image on the work buffer shown in FIG. 19 is shifted in the opposite direction to the above-mentioned 2.6.4. Map to a virtual object and draw in the frame buffer.

More specifically, as shown in FIG. 26, 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 2.6.4). ) And shift only pixels with α <αJ in the source α test, and pass only pixels with α = αJ in the destination α test.

As a result, the contour line EDL is also given to the left and upper sides 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. 28 is a flowchart relating to a process for generating 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. 29 is a flowchart relating to processing for generating a virtual polygon using a simple object as described with reference to FIGS. 18 (A) and 18 (B).

FIG. 29 differs from FIG. 28 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. 30 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 the 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. By doing so, as explained in FIG.
The Z value of the object at the contour drawing position is set to the contour Z
It can be set as a value.

Next, as described with reference to FIG. 20, 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. 21, 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 in FIG. 22, the mapping image on the work buffer is shifted to the virtual polygon by the bilinear filter method by shifting the texture coordinates U and V by (0.5, 0.5). 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 with reference to FIG. 26, the mapping image on the work buffer is mapped to the virtual polygon by shifting the texture coordinates U and V by (−0.5, −0.5) and using the bilinear filter method. 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. 27 in which a contour line is drawn in the inner area of the object can be obtained.

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 the interpolation, a contour line region (region where 0 <α <αJ) is determined in the inner region of the contour of the object OB, and a contour image is drawn in this region. .
By doing so, the contour line EDL of the object OB can be generated with a small processing load.

FIG. 31 shows the translucency of the outline as a distance (Z
It is a flowchart regarding the process changed according to (value). Note that the Z value increases as it is closer to the viewpoint.

First, ZN and ZF which are threshold values of the Z value
(VTN, VTF in FIG. 7A) and translucency αTN, αTF at the threshold values are set in advance (step S61).

Next, the representative Z value (Z value of the representative point) of the object to be drawn is obtained (step S62).

Next, based on the obtained representative Z value, a coefficient V for determining the translucency is obtained by the following equation (step S63).

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 translucency αT of the contour line is obtained as in the following equation (step S6).
4).

ΑT = (αTN−αTF) × V + αTF Next, the outline is translucently drawn using the obtained αT (step S65). The processing in step S65 corresponds to the translucent composition processing in steps S35 and S36 in FIG.

FIG. 32 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.

First, PN and PF (VT of FIG. 7B) which are threshold values of the size of the object to be drawn.
N, VTF) and translucency α TN, α at the threshold value
TF is set in advance (step S71).

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).
72).

Next, a coefficient V for determining the translucency is obtained as in the following equation based on the obtained pixel number P (step S73).

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

Next, the translucency αT of the contour line is obtained based on the obtained coefficient V (step S74). Then, the translucent drawing of the contour line is performed using the obtained αT (step S75). The processing in step S75 corresponds to the translucent composition processing in steps S35 and S36 in FIG.

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.

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

The 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 with 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.

Then, when each means of the present invention is executed by both hardware and a program, a program for executing each means of the present invention using hardware is stored in the information storage medium. 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. 34A 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. 34B 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. 34C 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. 34C, 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.

Further, 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).

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 a method for drawing a contour line in the inner region of the contour of an object, a method using texture mapping of the texel interpolation method is particularly desirable, but it is not limited to this.

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.

The virtual polygon generation method 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, although it is particularly desirable to discriminate the contour area of the object based on the α value subjected to texel interpolation, the present invention is not limited to this, and various modifications can be made.

In addition, various modifications can be made as a function characteristic of the distance from the viewpoint, the size of the object after perspective transformation, and the translucency of the contour line. For example, FIG.
Curve characteristics using a multi-dimensional function may be used instead of the linear characteristics as shown in (A) and (B). That is, for example, (V
Instead of linearly interpolating between (TN, αTN) and (VTF, αTF), interpolation may be performed with a multidimensional function.

As shown in FIGS. 35A and 35B, 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. In the case of FIGS. 35A and 35B, 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 translucency of the contour line may be kept substantially constant.

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 describing a technique for drawing a contour line in an inner region of an object contour;

FIGS. 4A to 4F are diagrams for explaining a comparative example. FIGS.

FIG. 5 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 an object after perspective transformation is small); is there.

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.

FIG. 9 is a diagram for explaining a method of setting the Z value of an object at the contour drawing position as the Z value of the contour line.

FIGS. 10A and 10B are diagrams for explaining problems that occur when a contour line is drawn in an outer region of the contour of an object.

FIG. 11 is an example of an image generated when a contour line is drawn in an inner region of the contour of an object and the Z value at the contour drawing position is set as the Z value of the contour line.

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 illustrating an example of an α plane generated on a frame buffer.

FIG. 21 is a diagram for illustrating an example of an original image and an α plane of an object generated on the frame buffer.

FIG. 22 is a diagram for describing a technique for 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 the frame image on the frame buffer;

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

FIG. 24 shows pixel R by bilinear filter method.
It is a figure for demonstrating the method of interpolating GB and alpha value.

FIG. 25 is a diagram for describing a method for generating an image of an outline of an object.

FIG. 26 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;

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

FIG. 28 is a flowchart illustrating a detailed example of processing according to the present embodiment.

FIG. 29 is a flowchart illustrating a detailed example of processing according to the present embodiment.

FIG. 30 is a flowchart illustrating a detailed example of processing of the present embodiment.

FIG. 31 is a flowchart showing a detailed example of processing of the present embodiment.

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

FIG. 33 is a diagram illustrating an example of a hardware configuration capable of realizing the present embodiment.

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

FIGS. 35A and 35B are diagrams showing other examples of functional characteristics of the distance from the viewpoint, the size of the object after perspective transformation, and the translucency of the contour line.

[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 (19)

(57) [Claims] 1. A game system for generating an image, comprising: a means for drawing an image of an object outline generated based on an object image in an inner area of the object outline; and means for generating an image of at viewpoint, the distance or size of the object after perspective transformation from viewpoint
Object image and object with translucency determined according to
A game system characterized by semi-transparent composition with the outline image of the project . 2. The game system according to claim 1, wherein the Z value of the object at the position where the contour line is drawn is set as the Z value of the contour line. 3. A game system for generating an image, wherein an image of an outline of an object generated based on the image of the object is drawn in an inner region of the outline of the object, and a given in the object space of and means for generating an image of the viewpoint, the object color information of the inside area of the outline of the object
Will be set and the outline will be
Generate a mapping image in which color information is set,
The mapping image has the texture coordinates as the first shift.
The virtual object using the texel interpolation method.
Texture mapping to the object, and then
The ping image is displayed with the texture coordinates in the second shift direction.
To a virtual object with texel interpolation
Object mapping by texture mapping
A game system characterized by generating an image of a line . 4. The game system according to claim 3 , wherein the mapping image is generated by drawing an object after perspective transformation in a drawing area in which outline color information is set as a background. . 5. The object according to claim 3 or 4 , wherein the virtual object includes all or part of an image of the object after perspective transformation and changes its size according to the size of the object after perspective transformation. The game system characterized by being. 6. The game system according to claim 5 , wherein the virtual object is generated based on the coordinates of the definition point of the object after the perspective transformation. 7. The virtual object according to claim 5, wherein when a simple object is set for the object, the virtual object is generated based on coordinates of a definition point of the simple object after perspective transformation. Game system. 8. The texel-interpolated α according to claim 3, wherein the α value set in the inner area of the object outline is different from the α value set in the outer area of the object outline. A game system characterized by discriminating an outline area in an inner area of an object outline based on a value. 9. In any of claims 1 to 8, after drawing the object in the drawing area, the image of the contour line, characterized in that it draws in the inner area of the contour of the drawn in each drawing area object Game system. 10. A program usable by a computer, comprising: a means for drawing an image of an object outline generated based on an object image in an inner area of the object outline; and a given program in an object space. as a means for generating at the viewpoint images, cause the computer to function, distance or size of the object after perspective transformation from viewpoint
Object image and object with translucency determined according to
A program characterized by semi-transparent composition with the outline image of the project . 11. The program according to claim 10, wherein the Z value of the object at the position where the contour line is drawn is set as the Z value of the contour line. 12. A program usable by a computer, wherein a contour image of an object generated based on an image of an object is drawn on an inner region of the contour of the object, and a given program in the object space. as a means for generating at the viewpoint images, cause the computer to function, color information of the object in the inner area of the contour of the object
Will be set and the outline will be
Generate a mapping image in which color information is set,
The mapping image has the texture coordinates as the first shift.
The virtual object using the texel interpolation method.
Texture mapping to the object, and then
The ping image is displayed with the texture coordinates in the second shift direction.
To a virtual object with texel interpolation
Object mapping by texture mapping
A program characterized by generating an image of a line . 13. The program according to claim 12 , wherein the mapping image is generated by drawing an object after perspective transformation in a drawing region in which outline color information is set as a background. 14. The object according to claim 12 , wherein the virtual object includes all or part of an image of the object after perspective transformation, and the size of the virtual object changes according to the size of the object after perspective transformation. A program characterized by being. 15. The program according to claim 14 , wherein the virtual object is generated based on coordinates of a definition point of the object after perspective transformation. 16. The virtual object according to claim 14, wherein when the simple object is set for the object, the virtual object is generated based on the coordinates of the definition point of the simple object after perspective transformation. program. 17. The method according to claim 12, wherein the α value set in the inner area of the object outline is different from the α value set in the outer area of the object outline, A program for discriminating an outline area in an inner area of an object outline based on a value. 18. The method according to claim 10 , wherein after the object is drawn in the drawing area, the outline image is drawn in an inner area of the outline of the object drawn in the drawing area. program. 19. An information storage medium usable by a computer, comprising the program according to claim 10. Description: