JP2001184515A - Image forming system and an information storage medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming system and an information storage medium, with which a problem in the plotting quality of an object can be solved with a little processing load. SOLUTION: On the basis of a depth value Z1 set to each of pixels in two- dimensional(2D) images (OB1-OB5, background) to become the moving field of a character and a depth value Z2 of the character, the hidden-surface removal of the character is performed. The depth value Z2 is found on the basis of the position, direction and moving history of the character or position at the feet of the character. The 2D image is divided into plural areas on the basis of the lower borderline of the 2D objects OB1-OB5, a plotting priority value for each of areas is determined on the basis of the position relation of lower borderlines, and the determined plotting priority value for each of areas is determined as the plotting priority value of a pixel inside each of areas. On the basis of the plotting priority value set to each of pixels, the depth value Z2 of the character is found. On the basis of a line, with which the lower borderline is extended just for the maximum width of the character, the 2D image is divided into plural areas.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an image generation system and an information storage medium.

[0002]

2. Description of the Related Art Conventionally, a three-dimensional object composed of a plurality of polygons (primitive surfaces) is prepared, and an image in an object space in which these three-dimensional objects are arranged is generated. Image generation systems are known. According to this image generation system, an image that can be viewed from an arbitrary viewpoint in the object space can be generated, and the virtual reality of the player can be enhanced.

However, in this image generation system, since a three-dimensional object such as a character or a building is represented by a combination of two-dimensional polygons, the obtained image is artificial and lacks reality. If the number of polygons of the three-dimensional object is increased to solve this problem, the processing load of the image generation system becomes excessive, and the design of the three-dimensional object requires much labor and time.

On the other hand, an image generation system that generates an image by expressing a display object with a two-dimensional object instead of a three-dimensional object is conventionally known. According to this image generation system, it is possible to use, for example, a real image captured by a camera or the like as an image of a building or the like. Therefore, a more natural and realistic image can be generated with a smaller processing load than in the case of using a three-dimensional object composed of polygons.

However, in this image generation system, it is necessary to solve the problem of the drawing priority of the object. For example, when a moving object such as a character is moved on the screen, it is necessary to take measures so that the moving object is properly erased by a two-dimensional object such as a building.

In this case, as one method for solving such a problem of the drawing priority, a method of controlling the drawing order of two-dimensional objects can be considered. For example, if you want to represent a situation where the character is half-hiding behind a building, draw the character first,
After that, the drawing order is controlled so that the building is drawn.

[0007] However, in this method, in the overlapping portion between the two-dimensional objects, the drawing which should be performed only once is performed a plurality of times, and the processing is useless. Further, if the rendering priority of the object is to be expressed in detail by this method, there is a problem that the amount of image data becomes enormous.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide an image generation system and an information storage medium which can solve the problem of drawing priority of an object with a small processing load. Is to do.

[0009]

According to one aspect of the present invention, there is provided an image generating system for generating an image, wherein a second depth value of a moving object is obtained by a given processing routine. Depth value calculation means, a first depth value set for each pixel of the two-dimensional image serving as a moving field of the moving object, and a second depth value of the moving object obtained by the depth value calculation means. And means for erasing the hidden surface of the moving object on the basis of Further, an 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. Further, the program according to the present invention is a program usable by a computer (including a program embodied in a carrier wave), and includes a processing routine for executing the above means.

According to the present invention, a second depth value of a moving object such as a character is determined based on a given processing routine. Then, the hidden surface of the moving object is erased based on the obtained second depth value and the first depth value set for each pixel of the two-dimensional image (screen, world map). As a result, a two-dimensional image constituting a moving field of the moving object 2
The moving object can be interrupted between the dimensional objects, and the problem of the drawing priority of the object can be solved. That is, it is possible to generate an image in which only a part of the moving object is displayed and the other part is hidden by being hidden by the two-dimensional object.
This makes it possible to give the player the illusion of having a depth, even though the image is a two-dimensional image.

According to the present invention, the problem of the drawing priority can be solved without controlling the drawing order of the objects. Therefore, it is possible to draw the two-dimensional image only once, and it is possible to eliminate waste of processing.

The moving object is particularly preferably a two-dimensional object, but may be a three-dimensional object.

Further, according to the image generation system, the information storage medium and the program according to the present invention, the depth value calculating means includes:
A second depth value of the moving object is obtained based on a position, a direction, or a movement history of the moving object. By doing so, the optimal second position corresponding to the position, direction, and movement history (movement route, etc.) of the moving object
Can be given to the moving object.

[0014] In the image generation system, the information storage medium and the program according to the present invention, the depth value calculation means may include:
A second depth value is obtained for all pixels of the moving object based on the position of the representative point set at the bottom of the moving object. The representative point set at the bottom of the moving object is considered to be the point closest to the front of the moving object. Therefore, if the second depth values for all the pixels of the moving object are obtained based on the position of the lowermost representative point, the optimum second depth value of the moving object is obtained with a small processing load. be able to.

Further, in the image generation system, the information storage medium and the program according to the present invention, the depth value calculation means may include:
A second depth value of the moving object is obtained based on a drawing priority value set for each pixel of the two-dimensional image serving as a moving field of the moving object. By setting the drawing priority value for each pixel in advance, the second depth value of the moving object can be obtained by a simple and low-load process.

Further, according to the image generation system, the information storage medium and the program according to the present invention, the two-dimensional image is divided into a plurality of regions based on a lower boundary line of a plurality of two-dimensional objects constituting the two-dimensional image. Based on the positional relationship between the lower boundary lines, the drawing priority value of each region corresponding to each lower boundary line is determined, and the determined drawing priority value of each region is used as the drawing priority value of the pixel of each region. It is characterized by being set. In this way, the drawing priority value to be set for each pixel of the two-dimensional image can be obtained by simple processing, and appropriate hidden surface elimination of the moving object can be realized.

Further, the image generation system, the information storage medium and the program according to the present invention divide a two-dimensional image into a plurality of regions based on a line obtained by extending a lower boundary of a two-dimensional object by a predetermined distance. It is characterized by that. In this way, when the moving object moves from the left or right of the two-dimensional object, the moving object can be properly erased.

Further, the image generation system, the information storage medium and the program according to the present invention are characterized in that the given distance is a distance specified based on the size of a moving object. If it does in this way, various size (width)
Appropriate hidden surface elimination for the moving object can be performed.

[0019]

Preferred embodiments of the present invention will be described below with reference to the drawings.

1. Configuration FIG. 1 shows an example of a block diagram of the present embodiment. In the figure, the present embodiment only needs to include at least the processing unit 100 (or may include the processing unit 100 and the storage unit 170, or the processing unit 100 and the storage unit 170 and the information storage medium 180), and other blocks. (For example, the operation unit 16
0, the display unit 190, the sound output unit 192, the portable information storage device 194, and the communication unit 196) can be optional components.

The processing section 100 performs various processes such as control of the entire system, instruction of each block in the system, game processing, image processing, sound processing, and the like. Processor (CPU, DSP)
Or an ASIC (gate array or the like) or a given program (game program).

The operation section 160 is used by a player to input operation data, and its function can be realized by hardware such as a lever, a button, and a housing.

The storage unit 170 stores the processing unit 100 and the communication unit 1
A work area such as 96
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.
D, DVD), magneto-optical disk (MO), magnetic disk, hard disk, magnetic tape, or memory (RO
M) and the like. Processing unit 10
0 performs various processes of the present invention (the present embodiment) based on the information stored in the information storage medium 180. That is, the information storage medium 180 stores information (program or data) for executing the means (particularly, the blocks included in the processing unit 100) of the present invention (the present embodiment).

A part or all of the information stored in the information storage medium 180 is transferred to the storage unit 170 when the power to the system is turned on. Information storage medium 1
The information stored in 80 is a program code for performing the processing of the present invention, image data, sound data, shape data of a display object, table data, list data, information for instructing the processing of the present invention, and instructions for the processing. The information includes at least one of information for performing processing according to.

The display section 190 outputs an image generated according to the present embodiment.
LCD or HMD (Head Mount Display)
It can be realized by hardware such as.

The sound output section 192 outputs the sound generated according to the present embodiment, and its function can be realized by hardware such as a speaker.

The portable information storage device 194 stores personal data and save data of the player, and the portable information storage device 194 can be a memory card, a portable game device, or the like. .

The communication unit 196 performs various controls for communicating with an external device (for example, a host device or another image generation system), and has a function of various processors or an ASIC for communication. Hardware and programs.

A 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 the information storage medium of such a host device (server) is also included in the scope of the present invention.

The processing section 100 includes a game processing section 110, an image generation section 130, and a sound generation section 150.

Here, the game processing unit 110 accepts coins (price), sets various modes, progresses the game, sets a selection screen, obtains the position and direction of an object, and arranges a map object. Various game processes such as a process, a hit check process, a process of calculating a game result (result, a result), a process for a plurality of players to play in a common game space, and a game over process are performed by the operation unit 160. This is performed based on operation data, personal data from the portable information storage device 194, stored data, a game program, and the like.

The image generation unit 130 is provided with a game processing unit 110
A game image is generated in accordance with an instruction from and the like and output to the display unit 190. In addition, the sound generation unit 150 performs BGM, sound effects,
A game sound such as a voice is generated and output to the sound output unit 192.

The game processing unit 110 and the image generation unit 1
30, all of the functions of the sound generation unit 150 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 image generation unit 130 includes a depth value calculation unit 13
2. Includes a drawing unit 140.

The depth value calculation unit 132 gives a depth value Z2 (a depth value for interrupting the moving object between other two-dimensional objects) of a moving object (a two-dimensional or three-dimensional object) such as a character. The processing required by the processing routine is performed. More specifically, the depth value Z2 of the moving object is determined based on the position of the moving object (for example, the position of the representative point set at the bottom of the moving object), the direction, or the movement history (for example, the moving route, the moving order). Ask for.

The depth value calculation section 132 includes a drawing priority value acquisition section 134. That is, in the present embodiment, the drawing priority value PR is set for each pixel of the two-dimensional image (screen) serving as a moving field of the moving object.
(A value for specifying the drawing priority of the moving object) is set in advance. Then, the drawing priority value acquiring unit 134 acquires the set drawing priority value PR based on the position of the moving object and the like. Then, based on the acquired drawing priority value PR, a depth value Z2 for all pixels of the moving object is obtained.

The drawing unit 140 performs a drawing process of an object. More specifically, the drawing unit 140 includes the hidden surface erasing unit 14.
2 inclusive. Then, the hidden surface elimination unit 142 is based on the depth value Z1 set for each pixel of the two-dimensional image serving as a movement field of a moving object such as a character, and the depth value Z2 obtained by the depth value calculation unit 132. Then, the hidden surface of the moving object is erased. In this case, the hidden surface is erased by the Z buffer 172 included in the storage unit 170.
May be realized by a Z-buffer method utilizing the above, or may be realized by comparing the depth values Z1 and Z2 by a program.

As described above, by removing the hidden surface of the moving object using the depth values Z1 and Z2, the moving object can be interrupted between two-dimensional objects such as buildings, and the drawing priority can be reduced. Can solve the problem.

Note that the image generation system of the present embodiment
A system dedicated to the single player mode in which only one player can play, or a system including not only such a single player mode but also a multiplayer mode in which a plurality of players can play, may be used.

When a plurality of players play,
The game image and the game sound to be provided to the plurality of players may be generated using one terminal, or may be generated using a plurality of terminals connected by a network (transmission line, communication line) or the like. Is also good.

2. Features of the present embodiment In this embodiment, FIG.
As shown in FIG. 5, a character CH (moving object in a broad sense) moves using a two-dimensional image (screen, world map) constituted by a two-dimensional object OB1 to OB5 and the ground (background in a broad sense) as a moving field. I do.

When the character CH moves in the two-dimensional image as described above, it is necessary to draw the CH so that there is no inconsistency in the drawing priority between the character CH and another two-dimensional object. is there. For example, D
When the character CH moves as shown in FIG.
It is necessary to draw CH so that CH appears to be in front of B1. When the CH moves as indicated by D2, it is necessary to draw the CH so that the CH appears to be between OB1 and OB2. When the CH moves as shown in D3, it is necessary to draw the CH so that the CH appears to be behind OB3.

Therefore, in this embodiment, as shown in FIG.
First, a depth value Z1 is given to each pixel of the two-dimensional image which is a moving field of the character CH. That is, when the coordinates of the two-dimensional world map are X and Y, the depth value Z1 is Z1 = DEPTH1 (X,
Y). In the present embodiment, only a two-dimensional image of a part of the display area in the world map is output to the display unit, and the display area scrolls with the movement of the character CH or the progress of the game.

In this embodiment, the depth value Z1 of each pixel is compared with the depth value Z2 of the character CH (depth value for interrupting the character between two-dimensional objects). Then, the hidden surface of the character CH is erased based on the comparison result.

More specifically, the depth value Z1 of each pixel of the two-dimensional image is set, for example, as shown in FIG.
That is, the objects are arranged in descending order of the depth value Z1. For example, in FIG. 4, an object OB5 where Z1 = 4 is arranged, OB2 where Z1 = 3 is arranged, OB1 and OB4 where Z1 = 2 are arranged, and finally, Z1 = 1 Is arranged. In this case, for example, in the pixel of the overlapping portion of OB1 and OB2 indicated by E1, the object OB drawn later
The depth value Z1 = 2 of 1 will be overwritten. In addition, the depth value on the ground (background) and the depth value in a portion where the object is not extracted are set to the largest value (for example, 5).

The depth value Z1 for each pixel of the two-dimensional image may be manually set by a designer. Alternatively, when each object is made of a combination of parts, the depth value Z1 of each pixel of the two-dimensional image may be automatically generated based on priority information generated at the time of combining parts.

In this embodiment, as shown in FIG.
For example, based on the position P (XP, YP) of the representative point set below the character CH (for example, at the bottom in a broad sense)
The depth value Z2 of CH is obtained. And this depth value Z
2 and the depth value Z set for each pixel of the two-dimensional image
1 is overwritten and the image of the character is overwritten for the pixel of Z2 <Z1, and the overwriting is not performed for the pixel of Z2 ≧ Z1 (hidden surface removal).

For example, in FIG. 5, the objects OB1 and O
The character CH moves during B2, and in this case, the depth value Z2 of CH becomes 2. In the upper half pixel of the character CH, Z2 = 2, Z1 = 3, and Z2 <Z1, so that the character C
The H image is overwritten. On the other hand, in the lower half pixel of the character CH, Z2 = 2 and Z1 = 2, and since Z2 ≧ Z1, the image of the character CH is not overwritten. Therefore, it is possible to generate an image in which only the upper half of the character CH is overwritten and the lower half of the character CH is hidden, and the problem of the drawing priority can be solved.

As described above, according to the present embodiment, it is possible to move a character by using a two-dimensional image as a moving field, and to insert a character between two-dimensional objects constituting the two-dimensional image. This gives 2
Despite being a two-dimensional image, the player can be illusioned as if there is depth.

Further, in the present embodiment, for example, as the images of the objects OB1 to OB5 in FIG. 5, an actual photographed image taken by a camera, an image carefully drawn by a CG by a designer, or a picture drawn by a famous painter is used. be able to.
Therefore, a more natural and realistic image can be generated as compared with the case where the object is constituted by polygons.

As a method for solving the problem of the drawing priority, a method for controlling the drawing order of objects can be considered. In this method, first, FIG.
Draws the object OB2 at the back as shown in
Next, as shown in FIG. 6B, the character CH is drawn, and then, as shown in FIG. 6C, the object OB1 in front is drawn.

However, in this method, the drawing which should have been performed only once is performed a plurality of times at the location indicated by F1 in FIG. 6C, which is the overlapping portion of the objects OB1 and OB2. Waste occurs.

On the other hand, in the present embodiment, FIG.
In the place indicated by F1, the image of the object OB2 is not drawn from the beginning, and only the image of the object OB1 is drawn. That is, as shown in FIG.
Is prepared from the beginning, and a character CH is inserted between the objects OB1 and OB2 in the prepared two-dimensional image. Therefore, since the drawing of the two-dimensional image only needs to be performed once, waste of processing can be omitted. Further, since there is no need to control the drawing order of the objects OB1 and OB2, the processing load can be reduced.

Next, a method for obtaining the depth value Z2 of the character will be described.

In this embodiment, as shown in FIG. 7, for each pixel of a two-dimensional image which is a character moving field, a drawing priority value PR together with a depth value Z1 is displayed.
Is set. That is, X, Y
, The drawing priority value PR becomes PR = P
It is represented by the formula of RIORITY (X, Y).

In this embodiment, the depth value Z2 of the character is obtained based on the drawing priority value PR set for each pixel of the two-dimensional image and the position P (XP, YP) of the character, for example. I have.

The setting of the drawing priority value PR for each pixel of the two-dimensional image can be realized by, for example, the following method.

That is, as shown in FIG. 8, the lower boundary lines L1 to L5 (thick lines) of the objects OB1 to OB5 are set. Note that the objects OB1 to OB5
Must be arranged such that the directions of the lower boundary lines L1 to L5 do not coincide with the direction of the Y-axis. In addition, the ground (background) is a portion drawn at the innermost position.

Next, as shown in FIG.
1 to L5, a distance W to the left along the X-axis direction.
Just extend. Also, the right end of each of the boundary lines L1 to L5 is
It extends rightward by a distance W along the X-axis direction. Here, the distance W is a distance specified by the size of a moving object such as a character. As the distance W, for example, the maximum width of a moving object appearing in a game can be adopted.

Next, as shown in FIG.
A line (a dotted line) is extended upward (backward) along the Y-axis direction from an end point of the extension line of 1 to L5 until it hits another line.

As described above, in the present embodiment, the two-dimensional image (world map) is divided into a plurality of areas AR1 to AR5 based on the lower boundary lines L1 to L5 of the objects OB1 to OB5 constituting the two-dimensional image. Is divided into

Then, as shown in FIG. 10A, the divided areas AR1 to AR5 (objects OB1 to OB1)
Create a parent-child tree of OB5).

For example, as shown in FIG.
A line DL3 extending from the end point of the line in R3 is a region AR
1. AR1 (OB1) and AR due to collision with AR4
4 (OB4) is registered as a child of AR3 (OB3).

Since the line DL1 extending from the end point in the area AR1 hits the area AR2, the line DL2 (OB2)
Is registered as a child of AR1 (OB1).

In the area AR2, the line DL2 extending from the end point collides with the area AR5, so that AR5 (OB5)
Is registered as a child of AR2 (OB2).

In the area AR4, the line DL4 extending from the end point collides with the area AR5, so that AR5 (OB5)
Is registered as a child of AR4 (OB4).

Then, drawing priority values are assigned sequentially from the top of the parent-child tree created in this way.

For example, the drawing priority value PR3 of the area AR3 becomes 1, the drawing priority value PR1 of the area AR1 becomes 2, the drawing priority value PR2 of the area AR2 becomes 3, and the drawing priority value PR5 of the area AR5 becomes 4. , And the drawing priority value PR4 of the area AR4 becomes 2. The drawing priority value PR5 of the area AR5 is 4 on the left route and 3 on the right route. In this case, the larger value of 4 is adopted.

In this embodiment, the drawing priority values PR1 to PR5 determined as described above are used for the respective areas AR1.
This is set as a drawing priority value of a pixel within AR5. In addition, A which is a region below AR1 to AR5
The priority value PR0 of R0 is set to the smallest value (for example, 0).

In the present embodiment, the drawing priority value in the area where the character is located is adopted as the depth value Z2 of the character. That is, as shown in FIG. 11, when the position P (XP, YP) of the character CH is, for example, in the area AR1, the drawing priority value PR1 = 2 of AR1 is adopted as the depth value Z2 of the character CH. On the other hand, the position P (XP,
If (YP) is in the area AR3, for example, the drawing priority value PR3 = 1 of AR3 is adopted as the depth value Z2 of the character CH. By doing this,
The proper hidden surface elimination of the character as shown in FIG. 2 becomes possible.

The drawing priority value may be set in advance for each pixel of the two-dimensional image,
You may make it obtain | require in real time based on the information of a lower boundary line.

The depth value Z2 given to the character
The (drawing priority value) may be determined based on not only the position of the character but also the direction and movement history of the character. For example, as shown in FIG. 12, when the character CH moves along the movement route MR1 and is located at PA,
The depth value Z2 of the character CH is different from the case where the character CH moves along the movement route MR2 and is located at PA. That is, the depth value Z when moving along MR1
2 becomes larger (becomes deeper) than the depth value Z2 when moving along MR2. By thus determining the depth value Z2 of the character based on the movement route (movement history in a broad sense), it is possible to more accurately erase the hidden surface of the character.

In FIG. 9A, the lower boundary lines L1 to L5
Is extended by the distance W for the following reason. That is, FIG.
When the character CH is located in a place as shown in FIG. 3 (A), as shown in FIG.
Should be hidden by the object OB1.

However, unless the lower boundary line L1 is extended by the distance W, the position P (XP, YP) of the character CH does not belong to the area AR1. Therefore, the depth value Z2 of the character CH is not PR1 = 2, which is the drawing priority value of the area AR1, but becomes PR0 = 0, which is the drawing priority value of the area AR0. As a result, hidden surface elimination as shown in FIG. 13B is not performed, and there is a problem that the character CH is drawn on the object OB1.

If the lower boundary line L1 is extended by the distance W (the maximum width of the character) as in the present embodiment, such a problem is prevented from occurring, and proper hidden surface erasure can be performed.

3. Next, a detailed example of the process according to the present embodiment will be described with reference to the flowcharts in FIGS. 14, 15, and 17.

FIG. 14 is a flowchart relating to a character drawing process.

First, as described with reference to FIG. 11, the drawing priority value PR is obtained based on the position P (XP, YP) of the representative point set under the character's feet (step S1). Then, the acquired priority value PR is
This is adopted as the depth value Z2 of all pixels of the character (step S2). More specifically, an area to which the character belongs is specified based on the position P (XP, YP) of the character, and the drawing priority value associated with the area is adopted as the depth value Z2 of the character.

Next, it is determined whether or not the α value (transparency, translucency, opacity) of the pixel (U, V) of the character is 0 (transparent) (step S3). , S5 is skipped, and the routine goes to step S6.
As a result, the part where the picture of the character is not drawn is
It will be drawn as transparent. On the other hand, if the α value is not 0, the depth value Z2 of the character is set to the depth value Z1 (X
(P + U, YP + V) is determined (step S4). If Z2 <Z1, as described with reference to FIG. 5, the image (color data) of the pixel (U, V) is overwritten on the two-dimensional image (screen) (step S5). On the other hand, if Z2 ≧ Z1, step S5
Is skipped to prevent overwriting.

Next, it is determined whether or not processing has been completed for all pixels (step S6). If processing has not been completed, the process returns to step S3 to perform processing for the next pixel.

FIG. 15 is a flowchart relating to the setting processing of the drawing priority value.

First, the drawing priority values PRj of all the areas are set to 1, and 1 is substituted for PT to put all the objects in the object pool (step S11).

Next, a combination of the objects OBm and OBn is extracted from the object pool (step S12).

Next, the boundary lines (objects OBm, OB
n lower boundary line + extension line) Expression Y = f′m (X), Y =
It is determined whether there is an overlap in the value range of f'n (X) (step S13).

For example, as shown in FIG. 16, the equation of the lower boundary line of the object OBk is defined as Y = fk (X) (value range: ak ≦ X ≦ bk).

Then, let the length of the extension line be W, and ak ′ =
If ak−W and bk ′ = bk + W are defined, the equation of a boundary line obtained by extending the left end and the right end of the lower boundary line by W is as follows: Y = f′k (X) = fk (ak) (ak '≦ X <ak) Y = f′k (X) = fk (X) (ak ≦ X ≦ bk) Y = f′k (X) = fk (bk) (bk <X ≦ bk ′) Note that the value range of the above equation is (ak ′ ≦ X ≦ bk ′).

Then, in the case of FIG. 16, it is determined that, in the portion indicated by G1, the value ranges of the equations of Y = f′1 (X) and Y = f′2 (X) overlap.

When it is determined that there is overlap in the value ranges, if f′m (X)> f′n (X) in the common value range, the drawing priority value PRm for OBm is set to P.
T + 1 is substituted and if f′m (X) ≦ f′n (X),
PT + 1 to the drawing priority value PRn for OBn
Is substituted (step S14). On the other hand, when there is no overlap in the value ranges, the process of step S14 is skipped.

Next, it is determined whether or not there are remaining combinations (step S15).
Return to 2. On the other hand, when there are no remaining combinations and the processing for all the combinations is completed, PRk = P
The object that becomes T is taken out of the object pool, PT + 1 is substituted for PT, and the combination is initialized (step S16). By doing so, the object having the smallest drawing priority value among the objects in the object pool (for example, OB3 in FIG. 10A) is extracted from the object pool.

Next, it is determined whether or not the object remains in the object pool (step S17). If the object remains, the process returns to step S12.

As described above, a parent-child tree as shown in FIG. 10A is created, and the drawing priority value PRk set in each area ARk (OBk) is determined.

FIG. 17 shows a character position P (XP, Y
It is a flowchart regarding the acquisition process of the drawing priority value in P).

First, an infinite value is substituted for dY, 0 is substituted for j, and 1 is substituted for i (step S21).

Next, it is determined whether or not YP ≧ f′i (XP) (step S22). Then, YP ≧ f′i (X
In the case of P), it is determined whether or not YP−f′i (XP) ≦ dY (step S23). And YP-f'i
If (XP) ≦ dY, i is substituted for j and YP−f′i (XP) is substituted for dY (step S24).

Next, i is incremented by 1 (step S25), and it is determined whether or not i ≦ N (N is the total number of objects) (step S26). If i ≦ N, the process returns to step S22. If i> N, the drawing priority value at the position P (XP, YP) is set as
The drawing priority value PRj in the area ARj is adopted (Step S27).

The processing of FIG. 17 will be specifically described with reference to FIG.

First, in step S22, YP ≧ f′1
(XP), and YP−
It is determined that f′1 (XP) ≦ dY (infinity). Accordingly, in step S24, i = 1 is substituted for j, and YP-f'1 (XP) is substituted for dY.

Next, i = 2 in step S25, and the process returns to step S22. Then, in step S22, YP
It is determined that ≧ f′2 (XP), and it is determined in step S23 that YP−f′2 (XP) ≦ dY = YP−f′1 (XP). Accordingly, in step S24, i = 2 is substituted for j, and YP-f'2 (XP) is substituted for dY.

After the above processing is repeated until i = 5, the flow shifts to step S27. As a result, as the drawing priority value at the position P (XP, YP), the drawing priority value PRj = P in the area ARj = AR2
R2 = 3 will be adopted.

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

The main processor 900 has a CD982
(Information storage medium), a program transferred via the communication interface 990, or a program stored in the ROM 950 (one of the information storage media).
Various processes such as sound processing are executed.

The coprocessor 902 assists the processing of the main processor 900, has a multiply-accumulate unit and a divider capable of high-speed parallel operation, and executes a matrix operation (vector operation) at high speed. For example, when a physical simulation for moving or moving an object requires processing such as matrix operation, a program operating on the main processor 900 instructs the coprocessor 902 to perform the processing (request ).

The geometry processor 904 performs geometry processing such as coordinate transformation, perspective transformation, light source calculation, and curved surface generation. The geometry processor 904 includes a multiply-accumulate unit and a divider capable of high-speed parallel computation, and performs matrix computation (vector computation). Calculation) at high speed. For example, when performing processing such as coordinate transformation, perspective transformation, and light source calculation, 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 performs 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 an opening screen, an intermission screen, an ending screen, a game screen, or the like. The image data and sound data to be decoded are stored in the ROM 950,
It is stored on a CD 982 or transferred from outside via a communication interface 990.

The drawing processor 910 executes a high-speed drawing (rendering) process of an object composed of primitive surfaces such as polygons and curved surfaces. When drawing an object, the main processor 900
Uses the function of the DMA controller 970 to pass object data to the drawing processor 910,
If necessary, the texture is transferred to the texture storage unit 924. Then, the drawing processor 910 draws 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 the texture. The drawing processor 910 can also perform α blending (translucent processing), depth queuing, mip mapping, fog processing, trilinear filtering, anti-aliasing, shading processing, and the like. Then, when an image for one frame is written to the frame buffer 922, the image is displayed on the display 912.

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

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

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

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

[0111] The DMA controller 970 provides a DM between the processor and the memory (RAM, VRAM, ROM, etc.).
A transfer is controlled.

A CD drive 980 stores a CD 982 in which programs, image data, sound data, and the like are stored.
(Information storage medium) 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, a network connected to the communication interface 990 may be a communication line (analog telephone line, ISDN), a high-speed serial bus, or the like. Then, data can be transferred via the Internet by using a communication line. Further, by using the high-speed serial bus, data transfer between another image generation system and another game system becomes possible.

It should be noted that each means of the present invention may be entirely executed by hardware only, or executed only by a program stored in an information storage medium or a program distributed via a communication interface. Is 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, 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 the processors 902, 904, 906, 910, 930, etc., which are hardware, to perform processing, and passes data if necessary. Then, each processor 902, 904, 906, 910,
930 etc., based on the instruction and the passed data,
Each means of the present invention will be executed.

FIG. 20A shows an example in which the present 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 watching the game image projected on the display 1100. Various processors, various memories, and the like are mounted on a built-in system board (circuit board) 1106. Information (program or data) for executing each unit 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. 20B 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 watching the game image projected on the display 1200. In this case, the storage information is stored in a CD 1206 or a memory card 1208, 1209, which is an information storage medium detachable from the main system.

FIG. 20C shows a host device 1300,
The host device 1300 and the network 1302 (LA
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 and a memory. If the terminals 1304-1 to 1304-n are capable of generating a game image and a game sound in a stand-alone manner, the host device 1300 outputs the game image and the game sound.
A game program or the like for generating game sounds is transmitted to the terminal 1.
It is 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, and transmits them to the terminals 1304-1 to 1304-1.
1304-n and output at the terminal.

In the case of the configuration shown in FIG. 20 (C), each means of the present invention may be executed in a distributed manner between a host device (server) and a terminal. Further, the storage information for executing each means of the present invention may be stored separately in an information storage medium of a host device (server) and an information storage medium of a 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, a portable information storage device capable of exchanging information with the arcade game system and exchanging information with the home game system. (Memory card, portable game device) is desirable.

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

For example, in the invention according to the dependent claims of the present invention, a configuration in which some of the constituent elements of the dependent claims are omitted may be adopted. In addition, a main part of the invention according to one independent claim of the present invention may be made dependent on another independent claim.

The moving object of the present invention is particularly preferably a character or the like appearing in a role playing game, and the two-dimensional image serving as a moving field of the moving object is a map image of a town or the like in the role playing game. Although particularly desirable, the invention is not so limited.

The method for obtaining the second depth value of the moving object is particularly preferably the method described with reference to FIGS. 7 to 11, but is not limited to this. Also, the technique described with reference to FIG. 5 and the like is particularly desirable as a technique for removing the hidden surface of the moving object, but the technique is not limited to this.

The comparison between the first and second depth values is as follows.
It may be performed by hardware having a drawing function of the buffer method, or may be performed by software.

The first depth value and the drawing priority value are divided and compressed and stored in the storage means (memory), and only the first depth value and the drawing priority value in the area requiring processing are decompressed. It is desirable to use it. By doing so, the use efficiency of the storage means can be increased.

In this embodiment, when the moving object is 2
Although the case where the moving object is a three-dimensional object has been described, the moving object may be a three-dimensional object. In this case, a two-dimensional image (actual image,
With the CG image) as a moving field, a three-dimensional moving object (an object constituted by a primitive surface such as a polygon) moves.

The present invention can be applied to various games (role playing games, action games, shooting games, fighting games, robot fighting games, sports games, competition games, music playing games, dance games, etc.).

The present invention is applied to various image generation systems such as arcade game systems, home game systems, large attraction systems in which a large number of players participate, simulators, multimedia terminals, and system boards for generating game images. it can.

[Brief description of the drawings]

FIG. 1 is an example of a block diagram of an image generation system according to an embodiment.

FIG. 2 is a diagram for explaining hidden surface elimination of a character moving using a two-dimensional image as a moving field.

FIG. 3 shows a depth value Z1 for each pixel of a two-dimensional image.
FIG. 6 is a diagram for describing a method of setting a value.

FIG. 4 shows a depth value Z1 for each pixel of a two-dimensional image.
FIG. 6 is a diagram for describing a method of setting a value.

FIG. 5 is a diagram for explaining a method of performing hidden surface removal based on a depth value Z1 set for each pixel of a two-dimensional image and a character depth value Z2.

FIGS. 6A, 6B, and 6C are diagrams for explaining a method of a comparative example for controlling a drawing order. FIG.

FIG. 7 is a diagram for explaining a method of setting a drawing priority value PR for each pixel of a two-dimensional image.

FIG. 8 is a diagram for describing a method of setting a lower boundary line of each object.

9 (A) and 9 (B) show two diagrams based on the lower boundary line.
FIG. 4 is a diagram for describing a method of dividing a two-dimensional image into a plurality of regions.

FIGS. 10A and 10B are diagrams for explaining a method of setting a drawing priority value in each divided area.

FIG. 11 is a diagram for describing a method of determining a depth value Z2 of a character based on a drawing priority value set for each region.

FIG. 12 is a diagram for explaining a method of determining a depth value Z2 of a character based on a movement route (movement history) of the character.

FIGS. 13A and 13B are diagrams for explaining a method of extending a lower boundary line of an object by a given distance.

FIG. 14 is a flowchart illustrating an example of a character drawing process.

FIG. 15 is a flowchart illustrating an example of a setting process of a drawing priority value.

FIG. 16 is a diagram for describing a setting process of a drawing priority value.

FIG. 17 is a flowchart illustrating an example of processing for acquiring a drawing priority value at a character position.

FIG. 18 is a diagram for describing a process of acquiring a drawing priority value at a character position.

FIG. 19 is a diagram illustrating an example of a hardware configuration capable of realizing the present embodiment.

FIGS. 20A, 20B, and 20C are diagrams showing examples of various types of systems to which the present embodiment is applied;

[Explanation of symbols]

 Reference Signs List 100 processing unit 110 game processing unit 130 image generation unit 132 depth value calculation unit 134 drawing priority value acquisition unit 140 drawing unit 142 hidden surface removal unit 150 sound generation unit 160 operation unit 170 storage unit 172 Z buffer 180 information storage medium 190 display unit 192 Sound output unit 194 Portable information storage device 196 Communication unit

Continued on front page F-term (reference) 2C001 BA02 BA05 BC00 BC05 BC08 BC10 BD05 CB01 CB06 CB08 CC02 CC08 5B050 AA09 BA08 BA11 EA19 EA24 EA29 FA02 5B080 FA03 FA08 GA02

Claims (14)

[Claims] 1. An image generation system for generating an image, comprising: a depth value calculating means for obtaining a second depth value of a moving object by a given processing routine; and a two-dimensional image serving as a moving field of the moving object. Means for eliminating hidden surfaces of the moving object based on the first depth value set for each pixel of the moving object and the second depth value of the moving object obtained by the depth value calculating means. An image generation system, characterized in that: 2. The image generation system according to claim 1, wherein the depth value calculation means obtains a second depth value of the moving object based on a position, a direction, or a movement history of the moving object. 3. The moving object according to claim 1, wherein the depth value calculating means calculates a second depth value for all pixels of the moving object based on a position of a representative point set at a lowermost position of the moving object. An image generation system characterized in that it is obtained. 4. The moving object according to claim 1, wherein the depth value calculating means determines a moving object based on a drawing priority value set for each pixel of a two-dimensional image serving as a moving field of the moving object. An image generation system, wherein a second depth value is obtained. 5. The two-dimensional image according to claim 4, wherein the two-dimensional image is divided into a plurality of regions based on a lower boundary line of the plurality of two-dimensional objects constituting the two-dimensional image, and a positional relationship between the lower boundary lines is determined. Based on this, the drawing priority value of each area corresponding to each lower boundary line is determined,
An image generation system, wherein the determined rendering priority value of each area is set as a rendering priority value of a pixel of each area. 6. The image generation system according to claim 5, wherein the two-dimensional image is divided into a plurality of regions based on a line obtained by extending a lower boundary line of the two-dimensional object by a predetermined distance. . 7. The image generation system according to claim 6, wherein the given distance is a distance specified based on a size of a moving object. 8. An information storage medium usable by a computer, comprising: depth value calculating means for obtaining a second depth value of a moving object by a given processing routine; and a two-dimensional image of a moving field of the moving object. Means for eliminating hidden surfaces of the moving object based on the first depth value set for each pixel and the second depth value of the moving object obtained by the depth value calculating means. An information storage medium characterized by including a program for storing information. 9. The information storage medium according to claim 8, wherein the depth value calculating means obtains a second depth value of the moving object based on a position, a direction, or a movement history of the moving object. 10. The moving object according to claim 8, wherein the depth value calculating means calculates a second depth value for all pixels of the moving object based on a position of a representative point set at a lowermost position of the moving object. An information storage medium characterized by the following. 11. The moving object according to claim 8, wherein the depth value calculating means sets a moving object based on a drawing priority value set for each pixel of a two-dimensional image serving as a moving field of the moving object. An information storage medium, wherein a second depth value is obtained. 12. The two-dimensional image according to claim 11, wherein the two-dimensional image is divided into a plurality of regions based on a lower boundary line of a plurality of two-dimensional objects constituting the two-dimensional image. Based on this, the drawing priority value of each area corresponding to each lower boundary line is determined,
An information storage medium, wherein the determined drawing priority value of each region is set as a drawing priority value of a pixel of each region. 13. The information storage medium according to claim 12, wherein the two-dimensional image is divided into a plurality of regions based on a line obtained by extending a lower boundary line of the two-dimensional object by a predetermined distance. . 14. The information storage medium according to claim 13, wherein the given distance is a distance specified based on a size of a moving object.