JP2002024858A - Game system and information memory medium - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a game system with a memory medium of its information, which realizes processing of image generation, using a recursive generation of a self-similarity with small burden of processing and small memory capacity for use. SOLUTION: A self-similarity is generated recursively by the predetermined number of times of repeating by using L system and the like, in which the number of repeat of generating the self-similarity is varied according to the distance from the viewpoint. The image of an object, which varies its precision according to the distance from the viewpoint, is generated, based on the same recursive structure expression and on the number of repeating of varying according to the distance from the viewpoint. The recursive structure expression and form specific parameters are made variable on real-time basis in the situation change of a game, and according to which in particular, rewriting of codes of the recursive structure expression, addition of a new code and deletion of a code are carried out. In the case the code to be processed is the one of a recursive call, the process returns to operating the code within the structure expression to call, after the recursive call is executed, the process is moved to operating the code within the structure expression to be called, and all code operations come to an end.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a game system and an information storage medium.

[0002]

2. Description of the Related Art Conventionally, there has been known a game system for generating an image which can be viewed from a given viewpoint in an object space which is a virtual three-dimensional space. Popular as something you can do. Taking a game system that can enjoy a racing game as an example, a player operates a racing car (model) to run in an object space and competes with a racing car operated by another player or a computer. Enjoy a 3D game.

In such a game system, it is an important technical problem to generate a more realistic image in order to improve the virtual reality of the player. Therefore, it is desired that plants such as trees arranged on the map can be represented by more realistic images.

[0004] As a technique for realistically simulating the way branches and leaves are attached to such plants, botanist A.
A method called the L system devised by Lindenmayer has been conventionally known. In this L system, self-similar shapes are recursively generated based on a structural formula describing a plant generation rule and shape specification parameters (length of a branch, branch angle of a branch, and the like), so that a branch or a leaf of a plant is generated. Realistically simulate how to attach.

[0005] However, this L system is a CG (Computer Graphics) that does not require real-time processing.
However, it has not been used in game systems that require real-time processing. In order to realize the method of the L system in a game system, an important technical problem is how to generate an image of a plant using the L system with a small processing load and a small storage capacity. .

Meanwhile, as a technique for reducing the load of image generation processing in a game system, LOD (Lead) for switching models according to the distance from a viewpoint (virtual camera).
A technique called velOf Detail) has been conventionally known. In this conventional LOD, as shown in FIG.
When the distance between the viewpoint and the object is short, the object is represented by a model having a large number of polygons. When the distance between the viewpoint and the object is long, the object is represented by a model having a small number of polygons. Thus, the number of polygons to be drawn in one frame can be reduced while maintaining the quality of the obtained image.

However, in this conventional LOD, a plurality of models such as a short-distance model, a medium-distance model, and a long-distance model must be prepared as models representing objects. Therefore, as shown in FIG. 1B, there is a problem that the used storage capacity required for storing the model data is increased.

[0008] Further, the conventional LOD has a problem that a screen shock at the time of model switching is large. For example, when the player notices that the model has been switched when switching from the medium-distance model to the short-distance model, the virtual reality of the player is greatly impaired. As a method for solving this problem, a method for increasing the number of prepared models, such as a first distance model, a second distance model, a third distance model,... Is also conceivable. However, according to this approach,
The above problem that the used storage capacity of the model data is increased becomes more serious.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and an object of the present invention is to provide an image generation process utilizing recursive generation of a self-similar shape, with a small processing load and a small storage capacity. An object of the present invention is to provide a game system and an information storage medium that can be realized with a capacity.

[0010]

In order to solve the above-mentioned problems, the present invention relates to a game system for generating an image, comprising: means for recursively generating a self-similar shape by a given number of repetitions; Means for generating an image at a given viewpoint in the object space based on information obtained by recursive generation of a similar shape, and means for changing the number of repetitions according to the distance from the viewpoint. Features. 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 invention, a self-similar shape is generated recursively for a given number of iterations. Then, an image at a given viewpoint in the object space is generated based on the information obtained by this generation. For example, an image is generated by arranging basic parts based on information obtained by recursive generation of a self-similar shape, or a texture is generated based on the above information, and an image is generated using the generated texture. Generated.

According to the present invention, the number of repetitions changes according to the distance from the viewpoint. As a result, a change in the precision of the image of the object or the like can be realized with a small processing load of merely changing the number of repetitions.

The distance from the viewpoint may be a depth distance, a linear distance between the viewpoint and the object, or a parameter equivalent to these distances.

Further, the game system, the information storage medium and the program according to the present invention provide a method for generating a self-similar shape recursively based on a recursive type structural formula and a shape specifying parameter including the number of repetitions. An image of an object whose precision changes according to the distance from the viewpoint is generated based on the number of repetitions that changes according to the distance from the object and the same recursive structural formula.

This makes it possible to change the precision of the object image using the same recursive structural formula. Therefore, a more realistic image can be generated with a small storage capacity.

The present invention also provides a game system for generating an image, comprising: means for recursively generating a self-similar shape based on a recursive structural formula and a shape specifying parameter; Means for generating an image at a given viewpoint in the object space based on the information obtained by the means, and means for changing the recursive structural formula or the shape specifying parameter in real time according to a change in a game situation. It is characterized by including. 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 self-similar shape is recursively generated based on a recursive structural formula and a shape specifying parameter. Then, an image at a given viewpoint in the object space is generated based on the information obtained by this generation.

In the present invention, the recursive structural formula or the shape specifying parameter changes in real time according to a change in the game situation. Therefore, an appropriate image according to the game situation can be generated by a simple process of merely changing the recursive structural formula and the shape specifying parameter,
Real images can be generated with a small processing load.

Note that the game situation changes, for example,
When various events occur in the game world,
This is a case where parameters used for various determinations in the game processing change.

Further, the game system, the information storage medium and the program according to the present invention provide a game system,
The code included in the recursive structure is rewritten, a new code is added to the recursive structure, or the code included in the recursive structure is deleted.

In this manner, the seasons change with simple processing such as rewriting, adding, and deleting codes,
It becomes possible to express the state of trees growing, and a more realistic image can be generated with a small processing load.

Further, in the game system, the information storage medium and the program according to the present invention, the shape specification parameter may be:
The number of repetitions of the recursive generation of the self-similar shape, the length of the edge forming the self-similar shape, or in the case of including the branch angle of the edge, the number of repetitions, the length of the edge,
Alternatively, the branch angle of the edge is changed according to a change in a game situation.

By doing so, it is possible to express the manner in which the season changes, the manner in which trees grow, and the like by a simple process of changing the number of repetitions, the length of the edge, and the branch angle of the edge. A more realistic image can be generated with a small processing load.

Further, the game system, the information storage medium and the program according to the present invention, when arranging basic parts constituting an object on the basis of information obtained by recursively generating a self-similar shape, It is characterized in that parts are replaced according to changes in the game situation.

In this way, it is possible to change the image of the object in various ways while using the same recursive structural formula, and the virtual reality of the player can be improved.

The present invention also relates to a game system for generating an image, comprising: means for recursively generating a self-similar shape based on a recursive structural formula and a shape specifying parameter; Includes means for generating an image at a given viewpoint in the object space based on the information obtained by the above, and the code of the recursive structure to be processed is a code requiring a recursive call Executes a recursive call and moves on to the processing of the code of the recursive structure of the callee, and after all the code of the recursive structure of the callee has been processed, the recursive structure of the caller is processed. It is characterized by returning to code processing. 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 self-similar shape is recursively generated based on a recursive structural formula and a shape specifying parameter. Then, an image at a given viewpoint in the object space is generated based on the information obtained by this generation.

According to the present invention, when the code to be processed is a code requiring a recursive call (for example, a node code in node rewriting or an edge code in edge rewriting), the recursive call is executed. Then, the processing shifts to the processing of the code of the called structural expression. Then, on the condition that the processing of all the codes at the callee is completed, the process returns to the processing of the code of the structural formula of the caller. This makes it possible to reduce the amount of data (for example, position, rotation matrix, etc.) that must be temporarily stored in a stack or the like, thereby saving the storage capacity of the memory.

[0029]

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

1. Configuration FIG. 2 shows an example of a functional block diagram of a game system (image generation system) of the present embodiment. In this figure, in the present embodiment, at least the processing unit 100 may be included (or the processing unit 100 and the storage unit 170 may be included).
The other blocks can be optional components.

The operation section 160 is for the player to input operation data, and its function can be realized by hardware such as a lever, a button, a microphone, or 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
80 includes a program for performing the processing of the present invention, image data, sound data, shape data of a display object, information for instructing the processing of the present invention, information for performing the processing according to the instruction, and the like. Can be made.

The display unit 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 of a player, save data of a game, and the like. The portable information storage device 194 may be a memory card, a portable game device, or the like. Can be.

The communication unit 196 performs various controls for communicating with the outside (for example, a host device or another game system), and has a function of various processors or an ASIC for communication. This can be realized by hardware, a program, or the like.

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

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

The processing section 100 includes a game processing section 110, an image generation section 120, and a sound generation section 130.

Here, the game processing unit 110 receives coins (price), sets various modes, progresses the game, sets a selection screen, and sets the position and rotation angle of an object (one or more primitive surfaces). Processing for calculating (the rotation angle around the X, Y or Z axis), processing for moving the object (motion processing), processing for obtaining the position of the viewpoint (the position of the virtual camera) and the line of sight (the rotation angle of the virtual camera), the map object Such as processing for arranging objects in the object space, hit check processing, processing for calculating game results (results, results), processing for playing by a plurality of players in a common game space, or game over processing. The game processing is executed based on operation data from the operation unit 160 or a program.

The image generation unit 120 includes a game processing unit 110
For example, an image that can be viewed from a given viewpoint (virtual camera) in the object space is generated based on the game processing result from, and is output to the display unit 190.

The sound generation unit 130 performs various sound processes based on the game processing result from the game processing unit 110,
Generates sound such as GM, sound effect, or voice, and outputs the sound
92.

The game processing section 110 includes a self-similar shape generation section 112, a distance calculation section 114, a structural formula / parameter change section 116, and a part replacement section 118.

Here, the self-similar shape generation unit 112 performs a process of recursively generating a self-similar shape. Taking the case of using the method of the L system as an example, a self-similar shape based on a recursive structural formula and a shape specifying parameter including the number of repetitions, the length of an edge (branch) or the branch angle of an edge, and the like. Is performed recursively.

When an image is generated based on information obtained by recursively generating a self-similar shape, the image is generated by arranging basic parts constituting an object based on the obtained information. It may be generated, or a texture may be generated based on the obtained information, and an image may be generated using the generated texture.

The distance calculation unit 114 performs a process of calculating the distance from the viewpoint (the distance between the viewpoint and the object). Here, as the distance from the viewpoint, the depth distance of the object, the linear distance between the viewpoint and the object, or various parameters equivalent to these distances (for example, the size of the object after perspective transformation on the screen, etc.) are used. You can think.

The structural formula / parameter changing unit 116 converts a recursive structural formula and a shape specifying parameter (geometric parameter) into
A process of changing the distance from the viewpoint obtained by the distance calculation unit 114 or a change in the game situation is performed. More specifically, the number of repetitions of the self-similar shape included in the shape specifying parameter is changed according to the distance from the viewpoint, the code of the recursive type structural formula is rewritten according to the change in the game situation, or the recursive type Add new code to the structure or remove the code for recursive structures. Alternatively, the number of repetitions of the self-similar shape, the length of the edge forming the self-similar shape, and the branch angle of the edge are changed according to the change in the game situation.

The change in the game situation is, for example, a case where various events (burning event, seasonal change event, game stage change event, etc.) occur in the game world, and various judgments in the game processing (judgment of game progress). , Game results, etc.) (time parameters, character status parameters, etc.) change.

Information such as a recursive structural formula and a shape specifying parameter is stored in the main storage unit 172 included in the storage unit 170.

The parts replacing section 118 performs processing for replacing basic parts constituting an object according to changes in the game situation. That is, when arranging basic parts of an object based on information obtained by generating a self-similar shape, a different impression is obtained by replacing the basic parts while using the same structural formula and shape specifying parameters. Images can be generated.

It should be noted that the game system according to the present embodiment
The system may be a system dedicated to the single player mode in which only one player can play, or a system having not only such a single player mode but also a multi-player mode in which a plurality of players can play.

When a plurality of players play,
The game image and the game sound to be provided to the plurality of players may be generated using one terminal, or may be generated using a plurality of terminals (game machine, mobile phone, etc.) connected via a network (transmission line, communication line) or the like. ) May be generated.

2. 2. Features of this embodiment 2.1 L system First, the method of the L system used in this embodiment will be described.

The L system is regarded as a kind of fractal, and is a fractal method most suitable for mathematical expression of plants. The L system uses a recursive structural formula (code sequence) and shape specification parameters including the number of repetitions, the length of an edge (branch), the branch angle of an edge, and the like. The recursive structural formula is expanded the number of times specified by the number of repetitions included in the shape specifying parameter. Then, there are node rewriting and edge rewriting as methods of expanding the structural formula.

For example, if the following structural formula (1) is developed by node rewriting, a figure having a self-similar structure as shown in FIG. 3 is generated.

A → B [+ A] B [−A] BA (1) FIG. 4 shows a correspondence relationship table between each code included in the structural formula and the operation content of each code. “00” indicates the end of the code. "01 (A)", "02 (B)", "
03 (L) ”and“ 04 (F) ”represent nodes, branches,
Instruct the generation of leaves and flowers. "06 ([)", "0
7 (]) "indicates the start and end of the branch." 08
(+) "And" 09 (-) "indicate a right turn and a left turn." 0A (&) "and" 0B (＾) "indicate a right pitch,
Indicate left pitch. “0C (￥)”, “0D (/)”
Indicates right roll and left roll. "0E (|)
Instruct 180 degree rotation.

The above structural formula (1) is expanded as follows. First, since the first code of the structural formula (1) is "B", a branch B1 is generated as shown in FIG.
The length of each generated branch (edge in a broad sense) is specified by the shape specifying parameter. Since the code following the structural formula (1) is "[+ A]", a right branch node N1 is set as shown in FIG. 5B. The branch angle at each node is specified by a shape specifying parameter. Since the code following the structural formula (1) is "B", a branch B2 is generated as shown in FIG. 5C. Since the next code is "[-A]", FIG.
As shown in (D), a left branch node N2 is set. Since the next code is "BA", FIG.
, A branch B3 is generated and a node N3 is set. Since the processing of all the codes has been completed, a self-similar shape in which the length of the branch (edge) is halved is recursively generated at the positions of the nodes N1, N2, and N3 according to the rule of “A →”. That is, "B [+ A] B [-A] B" in the structural formula (1)
"B [+ A] B [-A] BA" is added to the "A" part of A "
To recursively expand the structural formula (1).

For example, as shown in FIGS.
At the position of the node N1, a self-similar shape (B11, B12, B13) of a right branch with half the length of the branch is generated.
Similarly, a self-similar shape of the left branch is generated at the node N2, and a self-similar shape in the straight traveling direction is generated at the node N3.

By repeating the recursive expansion of the structural formula (1) by the number of repetitions included in the shape specifying parameter, a complicated self-similar figure as shown in FIG. 3 can be generated.

On the other hand, when the following structural formula (2) is developed by edge rewriting, a figure having a self-similar structure as shown in FIG. 6 is generated.

B → B [+ B] B [−B] B (2) The structural formula (2) is expanded as follows. First, since the first code of the structural formula (2) is "B", a branch B1 is generated as shown in FIG. Since the code following the structural formula (2) is “[+ B]”, a right-branch branch B2 is generated as shown in FIG. 7B. Since the code following the structural formula (2) is "B", a branch B3 is generated as shown in FIG. 7C. Since the next code is "[-B]", FIG.
As shown in (D), a left branch B4 is generated. Since the next code is "B", a branch B5 is generated as shown in FIG. Since the processing of all the codes has been completed, the self-similar shape with the length of the branch (edge) halved according to the rule of “B →” is recursively placed at the positions of the branches B1, B2, B3, B4, and B5. Generate. That is, "B [+ B] B [-
"B" of "B" + B]-[B]
B ”is substituted, and the structural formula (2) is recursively expanded.

For example, as shown in FIGS.
At the position of the branch B1, self-similar shapes (B11, B12, B13, B14, B15) in which the length of the branch is halved are generated and overdrawn. Similarly, in branch B2, right branch, branch B3
, A self-similar shape in the straight traveling direction is generated and drawn over the branch B4.

By repeating the recursive expansion of the structural formula (2) by the number of repetitions included in the shape specifying parameter,
A figure having a complicated self-similar structure as shown in FIG. 6 can be generated.

In FIG. 8, based on information obtained by recursive generation of self-similar shapes as shown in FIGS. 3 and 6, basic parts (polygons) such as branches, leaves, flowers, etc. constituting an object OB (tree) are shown. , Etc.), and an image of the object OB is generated. That is, "
On the edge generated by the code of “B (02)”, branch parts are arranged along the direction, and on the edge generated by the code of “L (03)”, leaf parts are arranged along the direction. The flower parts are arranged along the direction on the edge that is arranged and generated by the code of “F (04)”.

In this way, it is possible to generate images of objects (trees) of various shapes by using only the basic parts and making only the structural formula different. In this case, since the data amount of the structural formula is at most about several hundred bytes, the used storage capacity of the memory is not reduced.

Further, by replacing the basic parts themselves, the variation of the image of the object can be easily increased.

For example, an image of an object having a different impression can be generated only by changing the shape or texture of the basic part. If various basic parts are prepared, these basic parts can be used properly depending on the game situation. Since the basic parts are a unit such as a branch or a leaf, even if several types are registered, the used storage capacity of the memory is not so much reduced.

It is to be noted that the figure itself drawn as shown in FIGS. 3 and 6 is adopted as an image of a tree, or the figure drawn as shown in FIGS. 3 and 6 is set as a texture. A desired image may be generated by mapping to an object.

2.2 L by Variable Control of Number of Repetitions
Realization of OD One feature of the present embodiment is that the number of repetitions of the generation of the self-similar shape is changed according to the distance from the viewpoint.

That is, as shown in FIG. 9A, when the distance from the viewpoint (the distance between the viewpoint and the object OB) is short, the number of repetitions of the generation of the self-similar shape (the number of recursions) is increased, and the object OB is increased. Increase the precision of

On the other hand, as shown in FIG. 9B, when the distance from the viewpoint is medium, the number of repetitions is also medium, and the precision of the object OB is medium.

As shown in FIG. 9C, when the distance from the viewpoint is long, the number of repetitions is reduced, and the precision of the object OB is reduced.

For example, when a self-similar shape is recursively generated based on a recursive type structural formula and the number of repetitions (shape specifying parameters) as in the L system, as shown in FIG. Based on the number of repetitions that change according to the distance and the same recursive structural formula, an image of the object OB whose precision changes according to the distance from the viewpoint is generated.

In this way, an image of the object OB can be generated with appropriate precision according to each distance, and a more realistic image can be generated with a small processing load.

FIGS. 9A, 9B, 9C, and 10
In the example, the distance step is divided into three steps such as short distance, medium distance, and long distance. However, the distance step may be divided into two steps or four or more steps.

For example, in the conventional LOD, FIG.
As shown in (A), a plurality of models such as a short-distance model, a medium-distance model, and a long-distance model are prepared as models representing objects, and the model to be used is switched according to the distance from the viewpoint. Was.

However, in this conventional example, FIG.
As shown in (1), model data is required for the number of prepared models. Therefore, there is a problem that the used storage capacity of the model data increases.

Further, there is also a problem that the shock of the screen at the time of model switching is large and the player notices that the model has been switched. If the number of models is further increased in order to solve this problem, the problem of increasing the amount of model data becomes more serious.

On the other hand, in the present embodiment, as shown in FIG. 10, images of the objects OB having different degrees of precision can be generated using the same structural formula. In other words, the precision of the object OB can be changed according to the distance from the viewpoint only by changing the number of repetitions according to the distance while using the same structural formula and the same basic parts. Therefore, LOD can be realized without preparing a large number of models, and the used storage capacity of the memory can be saved.

Further, according to the present embodiment, the precision of the object can be changed seamlessly by changing the number of repetitions seamlessly, and it is also possible to prevent a shock or the like occurring on the screen. Even when the number of repetitions is changed seamlessly in this way, the data amount of the structural formulas and basic parts is not changed.
There is no problem that the data amount of the model data is extremely increased as shown in FIG.

2.3 Changes in Structural Formula, Shape Specific Parameter, and Basic Parts According to Game Status In this embodiment, the recursive structural formula and shape specific parameters are changed in real time according to changes in the game status. I have.

For example, if the original structural formula is the following formula (3), an image of the object OB as shown in FIG. 11A is generated.

A → [+ ΔA −− / L] [− / A ++ F] + A (3) In the present embodiment, the code of the structural formula is rewritten according to a change in the game situation.

For example, when the flower code “F” in the above structural formula (3) is rewritten to the leaf code “L”, the structural formula becomes the following formula (4).

A → [+ ΔA −− / L] [− / A ++ L] + A (4) Using this structural formula (4), the image of the object OB in FIG. The image changes as shown in FIG.

In this embodiment, a code is added to the structural formula according to a change in the game situation.

For example, the code "[+
When {¥ L] [/ + L] "is added, the structural formula becomes as shown in the following formula (5).

A → [+ ΔA −− / L] [[+ ΔL] [/ + L] − / A ++ L] + A (5) By using this structural formula (5), FIG. The image of the object OB changes to an image as shown in FIG.

Note that the code of the structural formula may be deleted according to a change in the game situation.

For example, when the season in the game world changes (in a broad sense, when the game situation changes), by rewriting, adding, or deleting such a code, the image of the object OB is changed in each season. An appropriate image can be obtained according to this, and the realism of the image can be increased. Moreover, the necessary processing is only required to rewrite, add, or delete the structural formula code, so that the processing load is light.

Further, if an image change as shown in FIGS. 11A, 11B and 11C is to be realized by a model replacement method, a plurality of different types of polygon models are required, and the use of memory is not required. It will squeeze the storage capacity.

On the other hand, in the present embodiment, FIG.
Only one structural formula is required to generate the images of (A), (B), and (C), and the data amount of the structural formula is as small as several hundred bytes. Therefore, the used storage capacity of the memory can be greatly reduced as compared with the model replacement method.

In FIG. 12, according to the change of the game situation,
The number of repetitions included in the shape specifying parameter is changed. By changing the number of repetitions in this manner, the complexity of the shape of the object OB can be adjusted stepwise according to the game situation.

For example, if the time parameter is changed and the number of repetitions is increased as the time in the game world elapses, it is possible to express a state in which trees gradually grow.

Also, when the processing load on other objects becomes heavy and a change in the game situation occurs such that the processing of the processing unit 100 (CPU) in FIG. By doing so, it is possible to allow a margin for the processing of the processing unit 100.

Note that the length of the edge or the branch angle of the edge included in the shape specifying parameter may be changed according to a change in the game situation. For example, by changing the length of an edge (branch) according to a change in a time parameter, it is possible to express a state in which a tree is gradually growing.

In the present embodiment, the basic parts constituting the object are replaced according to the change of the game situation.

For example, in FIGS. 13A and 13B, the branch parts constituting the object OB are replaced according to changes in the game situation. That is, FIG. 13A uses a branch part to which a white texture is mapped, and FIG. 13B uses a branch part to which a brown texture is mapped.

For example, when the season of the game world is winter, branch parts to which a white texture is mapped as shown in FIG. 13A are used, and when the season of the game world is summer, FIG. A branch part to which a brown texture is mapped as shown in FIG. In this way, the object OB can be changed according to the seasonal change.
Is changed, and the virtual reality of the player can be increased.

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

FIG. 14 is a flowchart of the processing of the main routine.

First, the processing is initialized (step S
1). More specifically, a process of preparing a structural formula serving as an original shape, a shape specifying parameter, a basic part, and the like are performed.

Next, it is determined whether or not a tree burning event has occurred (broadly, whether or not a game event has occurred) (step S2). For example, in a flight simulation game, when an airplane crashes or a missile hits a forest on a map, a tree burning event occurs. When it is determined that a burning event has occurred, the process proceeds to a burning event process (step S3).

Next, a seasonal change process is performed (step S).
4). Then, a distance change process (step S5) and a time lapse process (step S6) are performed, and the process returns to step S2. These processes are performed, for example, for each frame.

FIG. 15 is a flowchart of the burning event process.

If it is determined that fire has been burned to the tree due to a crash of an airplane or a missile hit (step S1)
1) The code of the leaf and the code of the flower included in the structural formula representing the tree are deleted (step S12). Then, the branch parts are replaced with parts representing dead branches (step S13).

In this way, the tree is composed of only branch parts, and the branch parts are replaced with parts representing dead branches. Therefore, it is possible to make it appear as if the tree was burned by fire, and it is possible to increase the virtual reality of the player.

FIG. 16 is a flowchart of the seasonal change process.

First, it is checked which season is the current season in the game world (step S21). If the current season is spring, a bud code is added to the structural formula representing the tree (steps S22 and S2).
3). If the current season is summer, the bud code is rewritten to the flower code (step S24,
S25). If the current season is autumn, the code of the flower is rewritten to the actual code (steps S26 and S26).
27). If the current season is winter, the actual code is deleted from the structural formula (steps S28 and S2).
9).

In this way, the expression that trees are buds in the spring, the buds become flowers in the summer, the flowers become fruits in the fall, and the fruits do not fall in the winter. Becomes possible. by this,
Players can feel seasonal changes,
The virtual reality of the player can be increased.

FIG. 17 is a flowchart of the distance change processing (LOD).

First, the distance L from the viewpoint to the object
Is obtained (step S31). In this case, the size of the object after the perspective transformation on the screen may be set as the parameter of the distance L.

Next, it is determined whether or not the distance L is smaller than near (short distance) (step S32). And
If it is smaller, repeat (the initial value of the number of repetitions) is set as the number of repetitions R (step S33).

Next, it is determined whether or not the distance L is smaller than middle (medium distance) (step S34). If it is smaller, the repeat count R is set to repeat-
1 is set (step S35). On the other hand, if the distance L is m
If it is larger than idle, the number of repetitions R is r
Epeat-2 is set (step S35).

In this manner, the number of repetitions R decreases as the distance L from the viewpoint to the object increases (R decreases as L decreases), and the precision (shape of the shape) of the object depends on the distance from the viewpoint. Complexity) can be varied.

FIG. 18 is a flowchart of the time lapse processing.

First, it is determined whether or not the growth degree grow is smaller than the growth limit max (step S41). If it is smaller, the growth degree grow is incremented by one (step S42). And branches (edges)
Length = length × wew
It is obtained according to the formula of light (weighting coefficient) (step S43).

In this way, the length length of the branches increases with the passage of time, and it is possible to realistically express how the trees grow.

FIG. 19 is a flowchart of the structural formula expanding process.

First, n, which is an argument of code [n] of the structural formula, is reset to 0 (step S51).

Next, it is determined whether or not the code has ended (step S52). If the code has ended, the expansion processing of the structural formula ends. For example, the code included in the structural formula
Is 100, it is determined that the processing of the 100th code is the end of the code.

Next, it is determined whether or not code [n] is "00 (end of code)" (step 53). And "
In the case of "00", the process is returned from the recursive call destination to the call source (step S54).

Next, it is determined whether or not code [n] is "01 (node)" (step 55). And c
If mode [n] is "01", it is determined whether or not count (recursion depth, number of repetitions) is greater than 0 (step S56). If it is larger than 0, the count is decremented by 1 (step S57), and a recursive call is executed (step S5).
8). That is, it calls its own processing routine (structural formula expansion processing) and returns to step S51. Then, when returning from the recursive call destination in step S54,
t is incremented by 1 (step S59).

On the other hand, if count is determined to be 0 or less in step S56, n is incremented by 1 (step S69).

If it is determined as "N" in step S55, code [n] is set to "02 (branch), 03 (leaf), 0
4 (flower). 05 "(step S6).
0). If code [n] is "02-05", the corresponding part is drawn (step S61).
Then, the position XYZ to be the next start point is calculated (step S62), and n is incremented by 1 (step S69).

If it is determined as "N" in step S60, it is determined whether or not code [n] is "06 (branch start)" (step S63). code [n] is “0”
In the case of 6 ", the position XYZ at that time and the rotation matrix M are stacked on the stack (step S64), and n is incremented by 1 (step S69).

If "N" is determined in step S63, it is determined whether code [n] is "07 (branch end)" (step S65). code [n] is “0”
In the case of 7 ", the position XYZ and the rotation matrix M are taken out of the stack (step S66), and n is incremented by 1 (step S69).

If it is determined as "N" in step S65, code [n] is changed from "08 (right turn) to 0E (1
(Rotation by 80 degrees) "is determined (step S67).
If code [n] is “08 to 0E”, a process of obtaining a rotation matrix M is performed (step S68), and n
Is incremented by 1 (step S69).

The processing in FIG. 19 when the following structural formula (6) is expanded by node rewriting is shown in FIG.
(A) to (H) and FIG. 21 (A) to (D). It is assumed that the initial value of count (recursion depth) is 1.

A → B [+ A] B [−A] BA (6) First, in step S60 of FIG. 19, code [0] = 02
(B), the process proceeds to steps S61 and S62,
A branch B1 is generated as shown in FIG. Then, the flow shifts to step S69, where n = 1 is incremented.

Next, in step S63, code [1] =
It is determined to be 06 ([), and the process proceeds to step S64, where the position XYZ and the rotation matrix M at that time are stacked on the stack. Then, the flow shifts to step S69, where n = 2.

Next, in step S67, code [2] =
08 (+), and the processing of the rotation matrix M of the right branch is performed. Then, the process proceeds to step S69, where n =
It is incremented to 3.

Next, at step S55, code [3] =
01 (A) is determined, and the routine goes to Step S56. Then, in step S56, it is determined that count = 1> 0,
In step S57, the count is decremented to "0". Then, in step S58, a recursive call is executed as shown in FIG. 20B, and the processing shifts to the processing of the code of the structural formula of the callee (the structural formula in the lower layer of the recursion). That is, the process returns to step S51, where n = 0 is reset.

Next, as shown in FIGS. 20 (C) and 20 (D), branches B11, B12, and B13 are sequentially generated by the code of the structural formula of the callee while n is sequentially incremented. Then, in step S53, code [1]
2] = 00 (end of code), and step S54
Returns to the processing of the code of the structural formula of the caller (the structural formula in the upper layer of the recursion), and is incremented to count = 1 in step S59.

Next, as shown in FIGS. 20E and 20F, after the branch B2 is generated by the code of the structural formula of the caller, a recursive call is executed in step S58. Then, as shown in FIGS. 20 (G) and (H), branches B21, B22 and B23 are sequentially generated by the code of the structural formula of the call destination. Then, in step S53, code [1]
2] = 00 (the end of the code), step S
At 54, the process returns to the processing of the code of the calling structural formula.

Next, as shown in FIGS. 21A and 21B, after the branch B3 is generated by the code of the structural formula of the caller, a recursive call is executed in step S58. Then, as shown in FIGS. 21C and 21D, branches B31, B32, and B33 are sequentially generated based on the code of the structural formula of the call destination. Then, in step S53, code [1]
2] = 00 (the end of the code), step S
At 54, the process returns to the processing of the code of the calling structural formula.

As described above, in the present embodiment, when the code of the structural formula to be processed is the code (A) requiring a recursive call, the recursive call is executed in step S58, and the call destination Move on to the processing of the code of the structural formula.

That is, the recursive call is executed in FIG. 20B, and the processing shifts to the processing of the code of the structural formula of the call destination.
Then, by the processing of the code of the structural formula of the call destination, as shown in FIGS.
2, B13 is generated.

Then, as shown in FIG. 20 (D), when the processing of all the codes of the called structural formula is completed, the process returns to the processing of the code of the calling structural formula in step S54. That is, the branch B2 is generated as shown in FIGS. 20E and 20F by processing the code of the structural formula of the caller.

As described above, in the present embodiment, when the recursive call is executed, the processing of all the codes of the structural formula of the callee is terminated (FIG. 20 (D), FIG. 20).
(H), FIG. 21 (D)). Then, after the processing of all the codes of the called structural formula is completed, the processing returns to the processing of the code of the called structural formula (FIG. 20 (E), FIG. 21).
(A)).

[0144] By doing in this way, FIG.
Compared with the processing procedure shown in (J), the amount of data that must be temporarily stored in a stack or the like can be reduced, and resources such as a memory can be used effectively.

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 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 operation, and performs a matrix operation (vector operation). 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 expansion processor 906 performs a decoding process for expanding 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, bilinear filtering, 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.

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

A 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.

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

The 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.

[0157] 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 with another game system becomes possible.

It is to be noted that each means of the present invention may be entirely executed only by hardware, 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, the information storage medium stores a program for executing each means of the present invention using hardware. 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. 23A 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. 23B 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. 23C shows a host device 1300,
The host device 1300 and the network 1302 (LA
N, a small network such as N, or a wide area network such as the Internet).
An example is shown in which the present embodiment is applied to a system that includes 04-1 to 1304-n (game machine, mobile phone, etc.). In this case, the storage information is stored in an information storage medium 1306 such as a magnetic disk device, a magnetic tape device, or a memory that can be controlled by the host device 1300. Terminal 130
If 4-1 to 1304-n can generate a game image and a game sound in a stand-alone manner, the host device 1
From 300, a game program for generating a game image, a game sound, and the like are delivered to the terminals 1304-1 to 1304-n. On the other hand, if it cannot be generated stand-alone, the host device 1300 generates a game image and game sound, transmits them to the terminals 1304-1 to 1304-n, and outputs them.

In the case of the configuration shown in FIG. 23 (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 save 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 those described in the above embodiments, 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.

In the present embodiment, the L system has been mainly described as an example of a self-similar recursive generation method. It is particularly preferable that the self-similar recursive generation method in the present invention is an L system. It is also possible to use.

In this embodiment, a case where an image of a tree is generated has been mainly described as an example. However, the present invention is applicable to generation of various images such as plants other than trees, topography (mountains), and gaseous objects (clouds).

Also, various modifications can be made to the structure of the structural formula and the type of the shape specifying parameter.

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

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

[Brief description of the drawings]

FIGS. 1A and 1B are diagrams for explaining a problem of a conventional LOD. FIG.

FIG. 2 is an example of a functional block diagram of the game system of the embodiment.

FIG. 3 is a diagram for explaining node rewriting.

FIG. 4 is an example of a correspondence table between codes and their operation contents.

FIGS. 5A to 5J are diagrams for explaining node rewriting; FIG.

FIG. 6 is a diagram for describing edge rewriting.

FIGS. 7A to 7J are diagrams for explaining edge rewriting; FIG.

FIG. 8 is an example of an image of a tree (object) generated by the embodiment.

FIGS. 9A, 9B, and 9C are diagrams for explaining a method of changing the number of repetitions of generation of a self-similar shape according to a distance from a viewpoint.

FIG. 10 is a diagram for describing a method of changing the number of repetitions of generation of a self-similar shape according to a distance from a viewpoint.

FIGS. 11A, 11B, and 11C are diagrams for explaining a method of changing a structural formula according to a change in a game situation.

FIG. 12 is a diagram for describing a method of changing a shape specifying parameter (the number of repetitions) according to a change in a game situation.

FIGS. 13A and 13B are diagrams for explaining a method of replacing basic parts according to a change in a game situation.

FIG. 14 is a flowchart illustrating a detailed example of a process according to the embodiment;

FIG. 15 is a flowchart illustrating a detailed example of a process according to the embodiment;

FIG. 16 is a flowchart illustrating a detailed example of a process according to the present embodiment.

FIG. 17 is a flowchart illustrating a detailed example of a process according to the embodiment;

FIG. 18 is a flowchart illustrating a detailed example of a process according to the present embodiment.

FIG. 19 is a flowchart illustrating a detailed example of a process according to the present embodiment.

FIGS. 20A to 20H are diagrams for explaining a method of expanding a structural formula.

FIGS. 21A to 21D are diagrams for explaining a method of expanding a structural formula.

FIG. 22 is a diagram illustrating an example of a hardware configuration capable of realizing the present embodiment.

FIGS. 23A, 23B, and 23C are diagrams illustrating examples of various types of systems to which the present embodiment is applied; FIGS.

[Explanation of symbols]

 OB object 100 processing unit 110 game processing unit 112 self-similar shape generation unit 114 distance calculation unit 116 structural formula / parameter change unit 118 parts replacement unit 120 image generation unit 130 sound generation unit 160 operation unit 170 storage unit 172 main storage unit 180 information Storage medium 190 Display unit 192 Sound output unit 194 Portable information storage device 196 Communication unit

Claims (14)

[Claims] 1. A game system for generating an image, comprising: means for recursively generating a self-similar shape for a given number of repetitions; and an object space based on information obtained by recursive generation of the self-similar shape. A game system comprising: means for generating an image at a given viewpoint in the above; and means for changing the number of repetitions according to the distance from the viewpoint. 2. The method according to claim 1, wherein the self-similar shape is recursively generated based on a recursive type structural formula and a shape specifying parameter including the number of repetitions. The number of repetitions,
A game system for generating an image of an object whose precision changes according to the distance from a viewpoint, based on the same recursive structural formula. 3. A game system for generating an image, comprising: means for recursively generating a self-similar shape based on a recursive structural formula and a shape specifying parameter; and a recursive generation of the self-similar shape. Means for generating an image at a given viewpoint in the object space based on the obtained information; and means for changing the recursive structural formula or the shape specifying parameter in real time according to a change in a game situation. A game system characterized by the following. 4. The recursive structural formula according to claim 3, wherein a code included in the recursive structural formula is rewritten according to a change in a game situation, a new code is added to the recursive structural formula, or A game system characterized by deleting a code including: 5. The self-similar shape according to claim 3, wherein the shape specifying parameter is a number of recursive generations of a self-similar shape, a length of an edge forming the self-similar shape,
Alternatively, in the case where an edge branch angle is included, the number of repetitions, the edge length, or the edge branch angle is changed according to a change in a game situation. 6. The method according to claim 3, wherein the basic parts constituting the object are arranged based on information obtained by recursively generating a self-similar shape. A game system characterized in that the game system is replaced according to a change in a situation. 7. A game system for generating an image, comprising: means for recursively generating a self-similar shape based on a recursive structural formula and a shape specifying parameter; and a recursive generation of the self-similar shape. Means for generating an image at a given viewpoint in the object space based on the obtained information, and when the code of the recursive structure to be processed is a code requiring a recursive call, Executes a recursive call and moves to the processing of the code of the recursive structure of the callee, and after all the code of the recursive structure of the callee has been processed, the code of the recursive structure of the caller is processed. A game system characterized by returning to processing. 8. An information storage medium usable by a computer, comprising: means for recursively generating a self-similar shape for a given number of repetitions; and information based on information obtained by recursive generation of the self-similar shape. An information storage medium comprising: a program for executing: a means for generating an image at a given viewpoint in an object space; and a means for changing the number of repetitions according to a distance from the viewpoint. 9. The method according to claim 8, wherein the self-similar shape is recursively generated based on a recursive structural formula and a shape specifying parameter including the number of repetitions. The number of repetitions,
An information storage medium for generating an image of an object whose precision changes according to a distance from a viewpoint, based on the same recursive structural formula. 10. An information storage medium usable by a computer, comprising: means for recursively generating a self-similar shape based on a recursive type structural formula and a shape specifying parameter; Means for generating an image at a given viewpoint in the object space based on the obtained information; and means for changing the recursive structural formula or the shape specifying parameter in real time according to a change in a game situation. An information storage medium including a program to be executed. 11. The recursive structural formula according to claim 10, wherein a code included in the recursive structural formula is rewritten, a new code is added to the recursive structural formula, or the recursive structural formula is changed according to a change in a game situation. An information storage medium characterized by deleting a code containing the information. 12. The method according to claim 10, wherein the shape specifying parameter includes a number of repetitions of recursive generation of a self-similar shape, a length of an edge forming the self-similar shape,
Alternatively, when an edge branch angle is included, the information storage medium changes the number of repetitions, the edge length, or the edge branch angle according to a change in a game situation. 13. The method according to claim 10, wherein the basic parts constituting the object are arranged based on information obtained by recursively generating a self-similar shape. An information storage medium, which is replaced according to a change in situation. 14. An information storage medium usable by a computer, comprising: means for recursively generating a self-similar shape based on a recursive structural formula and a shape specifying parameter; and recursively generating the self-similar shape. Including a means for generating an image at a given viewpoint in object space based on the obtained information, and a program for executing, the recursive structure code being processed requires a recursive call If the code is a recursive call, execute the recursive call and move to the processing of the code of the recursive structure of the callee, and after all the code of the recursive structure of the callee have been processed, call An information storage medium characterized by returning to processing of an original recursive structural formula code.