JP3934097B2 - Image processing apparatus, image processing method, and program - Google Patents

Description

  The present invention relates to a technique for generating an object having fluctuation, such as a flame, using particles.

  Many techniques for generating flame objects in a three-dimensional virtual space have been proposed. One of them is a method using particles. In this method, a plurality of particles are arranged in a region expressing flame, and a behavior according to a predetermined formula is given to each particle. As a result, each particle individually moves irregularly. For example, by placing a spherical object that is brighter toward the center at each particle position, a flame object having fluctuations as a whole can be formed.

  However, in the above prior art, there is nothing between each particle, so if the number of particles is small, there will be a flame object with holes in some places, and depending on the number, there is a problem that it does not look like a flame. To deal with this problem, it is natural to increase the number of particles, but if the number of particles is increased, the calculation cost of calculating the behavior of each particle and the memory usage for managing the position of each particle Such processing costs increase, making it difficult to apply to a game that requires rendering of the game screen in real time.

  The present invention has been made in consideration of such points, and an object thereof is to reduce the processing cost related to the process of generating a flame object.

  Another object of the present invention is to reduce processing costs related to generation processing of an object having fluctuations, such as smoke and water, in addition to a flame object.

  In order to achieve the object of the present invention, for example, an image processing apparatus of the present invention comprises the following arrangement.

That is, an image processing apparatus that generates a flame object using a plurality of particles generated in a three-dimensional virtual space,
Setting means for setting an initial generation region of particles in the three-dimensional virtual space;
Initial value data recording means for recording initial movement direction and initial movement speed of particles generated in the initial generation region as initial value data;
First moving means for moving a virtual point generated periodically or irregularly at one end of a path preset in the three-dimensional virtual space in the direction of the other end of the path;
The data indicating the acceleration in a predetermined direction and the moving direction of the particles determined based on the initial value data are based on the positional relationship between the one or more virtual points moving on the path and the particles. A second moving means for moving the particles in the changed moving direction ;
Position recording means for sequentially recording data indicating each position of the particles moved by the second moving means;
A belt-like object generating means for generating a moving path of the particles as a belt-like object by disposing polygons between the positions indicated by the data recorded by the position recording means;
A plurality of data generated by performing the processing by the initial value data recording means, the second moving means, the position recording means, and the belt-like object generating means for each of a plurality of particles existing in the three-dimensional virtual space. A flame object is formed by a band-shaped object.

  In order to achieve the object of the present invention, for example, an image processing apparatus of the present invention comprises the following arrangement.

That is, an image processing apparatus that generates an object having fluctuation using a plurality of particles generated in a three-dimensional virtual space,
Setting means for setting an initial generation region of particles in the three-dimensional virtual space;
Initial value data recording means for recording initial movement direction and initial movement speed of particles generated in the initial generation region as initial value data;
First moving means for moving a virtual point generated periodically or irregularly at one end of a path preset in the three-dimensional virtual space in the direction of the other end of the path;
The data indicating the acceleration in a predetermined direction and the moving direction of the particles determined based on the initial value data are based on the positional relationship between the one or more virtual points moving on the path and the particles. A second moving means for moving the particles in the changed moving direction ;
Position recording means for sequentially recording data indicating each position of the particles moved by the second moving means;
A belt-like object generating means for generating a moving path of the particles as a belt-like object by disposing polygons between the positions indicated by the data recorded by the position recording means;
A plurality of data generated by performing the processing by the initial value data recording means, the second moving means, the position recording means, and the belt-like object generating means for each of a plurality of particles existing in the three-dimensional virtual space. An object having fluctuations is formed by the band-shaped object.

  In order to achieve the object of the present invention, for example, an image processing method of the present invention comprises the following arrangement.

That is, an image processing method performed by an image processing apparatus that generates a flame object using a plurality of particles generated in a three-dimensional virtual space,
An initial value data recording step of recording the initial movement direction and initial movement speed of particles generated in the initial generation region in the three-dimensional virtual space in the memory of the image processing apparatus as initial value data;
A route setting step of reading data defining a route in the three-dimensional virtual space from the memory and using the read data to set the route in the three-dimensional virtual space;
A first movement step of moving a virtual point generated periodically or irregularly at one end of the route set in the route setting step toward the other end of the route;
The data indicating the acceleration in a predetermined direction and the moving direction of the particles determined based on the initial value data are based on the positional relationship between the one or more virtual points moving on the path and the particles. A second moving step of moving the particles in the changed moving direction ,
A position recording step of sequentially recording data indicating each position of the particles moving in the second moving step in the memory;
A belt-shaped object generating step of generating a moving path of the particles as a band-shaped object by arranging polygons between the positions indicated by the data recorded in the position recording step;
A plurality of data generated by performing the initial value data recording process, the second movement process, the position recording process, and the strip object generation process for each of a plurality of particles existing in the three-dimensional virtual space. A flame object is formed by a band-shaped object.

  In order to achieve the object of the present invention, for example, an image processing method of the present invention comprises the following arrangement.

That is, an image processing method performed by an image processing apparatus that generates an object having fluctuation using a plurality of particles generated in a three-dimensional virtual space,
An initial value data recording step of recording the initial movement direction and initial movement speed of particles generated in the initial generation region in the three-dimensional virtual space in the memory of the image processing apparatus as initial value data;
A route setting step of reading data defining a route in the three-dimensional virtual space from the memory and using the read data to set the route in the three-dimensional virtual space;
A first movement step of moving a virtual point generated periodically or irregularly at one end of the route set in the route setting step toward the other end of the route;
The data indicating the acceleration in a predetermined direction and the moving direction of the particles determined based on the initial value data are based on the positional relationship between the one or more virtual points moving on the path and the particles. A second moving step of moving the particles in the changed moving direction ,
A position recording step of sequentially recording data indicating each position of the particles moving in the second moving step in the memory;
A belt-shaped object generating step of generating a moving path of the particles as a band-shaped object by arranging polygons between the positions indicated by the data recorded in the position recording step;
A plurality of data generated by performing the initial value data recording process, the second movement process, the position recording process, and the strip object generation process for each of a plurality of particles existing in the three-dimensional virtual space. An object having fluctuations is formed by the band-shaped object.

  With the configuration of the present invention, it is possible to reduce the processing cost related to the flame object generation process. Further, not only the flame object but also the processing cost related to the generation processing of the object having fluctuations such as smoke and water can be reduced.

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

[First Embodiment]
In the present embodiment, “an object expressing flame (hereinafter referred to as a flame object)” is generated as an object having “fluctuation”. Hereinafter, the generation process of the “flame object” will be described in more detail.

  FIG. 1 is a block diagram illustrating a basic configuration of a computer that functions as an image processing apparatus that executes a process of generating a “flame object” according to the present embodiment.

  Reference numeral 101 denotes a CPU that controls the entire apparatus using programs and data stored in the RAM 102 and the ROM 103, and executes the above-described “fire object” generation process according to the present embodiment.

  Reference numeral 102 denotes a RAM which has an area for temporarily storing programs and data loaded from the external storage device 107 and the storage medium drive device 108 and a work area used by the CPU 101 for executing various processes. .

  Reference numeral 103 denotes a ROM which stores a boot program, data related to the setting of the apparatus, and the like.

  Reference numerals 104 and 105 denote a keyboard and a mouse, which are used for inputting various instructions to the CPU 101. In addition, as a device that can input various instructions to the CPU 101, other devices such as a joystick and a game pad can be used.

  A display unit 106 includes a CRT, a liquid crystal screen, and the like, and can display processing results by the CPU 101 by information such as images and characters.

  Reference numeral 107 denotes an external storage device that functions as a large-capacity information storage device such as a hard disk drive device. The OS (operating system) and the CPU 101 generate the above “flame object” according to the present embodiment described later. Programs and data for executing processing, data of a three-dimensional model described below (when the three-dimensional model is expressed by polygons, each vertex coordinate position of each polygon constituting the three-dimensional model, each The data indicating the normal vector of the polygon, and the texture data, etc. when mapping the texture to this three-dimensional model are stored, and these are read out to the RAM 102 as needed under the control of the CPU 101. It is.

  Reference numeral 108 denotes a storage medium drive device that reads out programs and data recorded on a storage medium such as a CD-ROM or DVD-ROM and outputs them to the RAM 102 or the external storage device 107. Note that a program or data for causing the CPU 101 to execute a “flame object” generation process according to the present embodiment, which will be described later, or the data of the three-dimensional model may be recorded in this storage medium. These programs and data are read from the storage medium by the storage medium drive device 108 under the control of the CPU 101 and output to the RAM 102. If the storage medium is a writable medium such as a CD-R or a DVD-RAM, the storage medium drive device 108 performs a process of writing a program and data to the storage medium under the control of the CPU 101.

  Reference numeral 109 denotes a bus connecting the above-described units.

  Next, a “flame object” generation process according to this embodiment, which is performed by a computer having the above-described configuration, will be described.

  FIG. 2 is a diagram for explaining an initial generation region of particles used for generating a flame object. In the figure, reference numeral 201 denotes a three-dimensional model of “candle”, and 202 denotes an allowable area that an initial position for generating particles can take in order to generate and arrange a flame object on the candle.

  The three-dimensional model 201 is a model having a three-dimensional shape in a three-dimensional virtual space. For example, the shape is represented by a plurality of polygons, and a texture image is mapped on the surface (on the polygon) as necessary. ing. Since such a three-dimensional model representation method is a well-known technique, further explanation is omitted.

  Reference numeral 202 denotes an area for generating particles, and the particles are generated at randomly determined positions in the area 202. As a method for setting the initial generation area 202, for example, the center position of the area 202 is set on the three-dimensional model 201, and the maximum radius from the center position is set. In this case, the particle generation method is to determine a direction and a radius (a radius that is larger than 0 and equal to or less than the maximum radius) from the center position, and only the radius determined in the direction determined from the center position. Particles can be generated at advanced positions.

  In this embodiment, the initial generation region of the particle is provided on the three-dimensional model of the candle with the setting that the flame is present on the candle. However, this region is located at any position in the three-dimensional virtual space. It will be apparent from the following description that even if provided, the flame object generation processing according to the present embodiment is applicable.

  Next, the behavior given to the particles generated in the initial generation region will be described. FIG. 3 is a diagram for explaining the contents set for the particles in order to give behavior to the particles generated in the initial generation region 201 shown in FIG. In the figure, the same parts as those in FIG. 2 are denoted by the same reference numerals, and the description thereof is omitted. In addition, a plurality of particles are generated in the initial generation region, and one of them will be described below as an example. This description can be similarly applied to a plurality of other particles.

  In the figure, reference numeral 301 denotes a particle. When the particle 301 is generated in the initial generation region, an initial moving direction and an initial moving speed are set for the particle 301. In addition, generating a particle includes giving an initial position of the particle.

  In this embodiment, the initial moving direction and the initial moving speed are expressed by a speed vector (V in the figure). As shown in the figure, there are three elements constituting the velocity vector V, vx, vy, and vz, and these three elements follow the coordinate system in the three-dimensional virtual space. Therefore, the moving direction of the particles in the three-dimensional virtual space can be expressed by these three elements.

Therefore, if the current particle position is X (X = [x y z] ^T ),
X = X + V
That is,
x = x + vx
y = y + vy
z = z + vz
This particle 301 moves in the set velocity vector direction by the magnitude of this vector.

  Therefore, when particles are generated in the initial generation region, first, a velocity vector is set for the generated particles. The setting of the velocity vector is to determine the above three elements constituting the velocity vector, and the elements of the velocity vector, vx, vy, and vz are values determined at random within a certain range. However, this determination method is not particularly limited.

  Each time a particle is generated in this way, a velocity vector is set for the particle, but the set velocity vector data is sequentially recorded in the RAM 102. As a result, the velocity vector data of the currently generated particles is recorded in the RAM 102, and the currently generated particle velocity vectors can be managed.

  When particles are generated, data indicating the life span is generated along with the velocity vector, which will be described in detail later.

  On the other hand, data indicating the direction in which the flame rises in the three-dimensional virtual space, that is, the upward acceleration with respect to the candle, is created in advance and recorded in the external storage device 107 or the storage medium. It is loaded from the storage medium into the RAM 102 by the storage medium drive device 108.

  That is, when the calculation according to the above formula X = X + V is repeated, the position of each particle becomes one movement away from the initial generation region.

Thus, in this way, in the three-dimensional virtual space, when the acceleration direction of the flame, that is, the upward acceleration with respect to the candle is provided and this acceleration is a (a = [ax ay az] ^T ),
V = V + a
That is,
vx = vx + ax
vy = vy + ay
vz = vz + az
If X = X + V is calculated using the calculated V, the particle movement initially moves in the initial movement direction set for each, but gradually moves up to the flame, that is, in the candle. On the other hand, it moves in the upward direction.

  In summary, in order to move the particles in this way, V = V + a is calculated, and then X = X + V is calculated using the updated V.

  However, with the above calculations alone, the respective particles eventually move in parallel and upward in the direction of the candle, and there is no “fluctuation” unique to the flame in their behavior. Therefore, a process for giving a “fluctuation” behavior to each generated particle will be described next.

  FIG. 4 is a diagram showing a mechanism for giving a “fluctuation” behavior to each generated particle. In the figure, the same parts as those in FIG. 2 are denoted by the same reference numerals, and the description thereof is omitted.

  In the figure, 401 is a path extending in a spiral upward direction from the upper surface (shaded portion in the figure) of the three-dimensional model 201, and 402a, 402b, and 402c move on the path 401 in the direction of the arrow in the figure. It is a gravity point that rises upward. The path 401 and the gravity points 402a, 402b, and 402c are provided for calculation for the processing described below, and are not displayed. Although the number of gravity points is three in the figure, it will be clear from the following description that the essence of the following description is not limited to this number.

  Gravity points (402a, 402b, 402c) are generated at one end of the path 401 (position indicated by 403 in the figure) on the upper surface of the three-dimensional model 201 periodically or irregularly in sequence, as described above. 401 is moved in the direction of the arrow in FIG. For example, in the case of the figure, the gravity point 402c occurs first and moves on the path 401 in the direction of the arrow in the figure. Then, after elapse of a predetermined time, a gravity point 402b is generated next, and similarly moves on the path 401 in the direction of the arrow. Further, after a predetermined time has passed, a gravity point 402a is generated next, and similarly, moves on the path 401 in the direction of the arrow. The moving speed of each gravity point may be the same or different. Since the length of the path 401 is finite, when the gravity point moving on the path 401 comes to the other end of the path 401 (position indicated by 404 in the figure), the gravity point is to erase. Then, the process of generating a gravity point at the position of one end 403 is repeated.

  The above data indicating the path 401 (for example, data on the coordinate position of each control point in order to generate the path 401 using a free curve) is generated in advance and is loaded into the RAM 102 as necessary. Further, the generation and movement processing of each gravity point is performed by the CPU 101.

  Next, a process for controlling the movement direction of the particles using each gravity point and giving “fluctuation” to the movement will be described.

  FIG. 5 is a diagram for explaining processing for controlling the moving direction of the particles by the two gravity points 402a and 402b. In the figure, the same parts as those in FIG. 4 are denoted by the same reference numerals, and the description thereof is omitted.

In the figure, reference numeral 501 denotes particles, and 402a and 402b denote gravity points. First, a distance r1 between the particle 501 and the gravity point 402a is obtained. And the following formula F1 = k / (r1 × r1)
To calculate the value of F1. Here, k = 1 is set to k = 1 to simplify the description. Then, g1 (vector obtained as a result of subtracting the position X of the particle 501 from the position Y of the gravity point 402a) from the position of the particle 501 to the position of the gravity point 402a is obtained, and using the obtained vector g1, f1 = F1 × g1 / | g1 |
To obtain a vector f1. Here, | g1 | indicates the magnitude of the vector g1. That is, the vector f1 represents a force vector that the particle 501 is attracted to the gravity point 402a because the gravity point 402a exists.

Similarly, the distance r2 between the particle 501 and the gravity point 402b is obtained this time. And the following formula F2 = k / (r2 × r2)
To calculate the value of F2. Then, a vector g2 (a vector obtained as a result of subtracting the position X of the particle 501 from the position Z of the gravity point 402b) from the position of the particle 501 to the position of the gravity point 402b is obtained, and using the obtained vector g2, f2 = F2 × g2 / | g2 |
To obtain a vector f2. Here, | g2 | indicates the magnitude of the vector g2. That is, the vector f2 represents a force vector that the particle 501 is attracted to the gravity point 402b because the gravity point 402b exists.

  As described above, the processing for obtaining the vector of the force (f1, f2 in the figure) acting on the particle 501 due to the presence of the gravity point is performed for all gravity points in the vicinity of the position of the particle 501. Of the gravity points existing on the path 401, there is no particular limitation as to whether the force drawn against the gravity point is calculated.

  Next, since force vectors f1 and f2 are obtained in the same figure, these vectors are combined, and the resultant vector is represented by f3. Therefore, in the figure, the force vector acting on the particle 501 due to the presence of the gravity points 402a and 402b can be obtained as f3.

  The direction of movement of the particle 501 is controlled by the force vector f3. More specifically, the direction of acceleration relative to the particle 501 is controlled. Therefore, (a + f3) may be used instead of the acceleration a. That is, V = V + (a + f3) is calculated, and then X = X + V is calculated using the updated V.

  In this way, by generating a plurality of gravity points and moving each of them, the distance from the particle already generated changes dynamically, so the direction and magnitude of the force vector applied to the particle also changes. As a result, the behavior of the particles can be fluctuated.

  FIG. 6 is a diagram for explaining the behavior given to each particle by the above processing. As described above, the particles 601 to 604 shown in the figure each change the direction of the vector f3 according to the distance from any one of the gravity points 402a, 402b, 402c, 402d, and 402e. Moving in different directions.

  By the above processing, each particle initially moves in the initial moving direction set for each particle, but gradually moves in the flame rising direction, that is, in the upward direction with respect to the candle. The movement direction can be fluctuated by the influence of the existence of the gravity point.

  Next, a process for generating a flame object using particles exhibiting such behavior will be described. In the present embodiment, the flame object is represented by a plurality of band-like objects. Each band-like object is generated based on the movement trajectory of one particle. In the following description, one band-shaped object among a plurality of band-shaped objects will be taken as an example, and processing for generating this band-shaped object will be described.

  The CPU 101 records the moved position as data in the RAM 102 every time the particle position is moved by the above processing. FIG. 7 is a diagram showing a movement locus of a certain particle (target particle). In the figure, reference numeral 701 indicates the locus of movement of the target particle, and points 702 to 707 indicate positions where the target particle has been moved according to the above equation.

  As described above, when the particles are generated, data indicating the life span is generated together with the velocity vector. The lifespan indicates the time during which particles exist in the three-dimensional virtual space. When the CPU 101 generates particles, it starts timing using an internal timer (not shown). When a plurality of particles are generated, the time elapsed after the generation of each particle is counted. When the time measured after the generation of the particle reaches the life span set for the particle, the particle is deleted from the three-dimensional virtual space, and the band-like pattern described below using the data related to the particle is used. After the processing for generating the object is performed, the data relating to the particles is discarded.

  Accordingly, since the length of the locus of movement of the particles is naturally finite, the data indicating each position where the particles have moved is also a finite number. In the example of FIG. 7, since the target particle is sequentially moved at the six positions indicated by 702 to 707, the data of the six positions indicated by 702 to 707 are sequentially stored in the RAM 102 for the target particle. Become.

  FIG. 8 is a diagram illustrating a table for managing data at each position where the target particle has moved, which is stored in the RAM 102. In the figure, the target particle has moved at N positions, and each position (which is a position in the three-dimensional virtual space, is represented by three coordinate values of x, y, and z). It is sequentially registered in this table.

  Next, processing for generating a strip-like object using this table will be described. Naturally, the flame object generated by the flame object generation process according to the present embodiment is viewed from the position of the viewpoint provided in the three-dimensional virtual space. Therefore, the surface of the band must face the viewpoint side so that the band-shaped object composing the flame object can also be seen from this viewpoint. Hereinafter, generation of such a band-like object will be described.

  FIG. 9 is a diagram for explaining processing for generating a strip-shaped object according to the present embodiment. In the band-shaped object according to the present embodiment, polygons (hereinafter referred to as band polygons) are arranged between the positions where the particles have moved, so that the movement path of the particles is expressed by a band-shaped object.

In the figure, a process of arranging a polygon between the position P _n−1 and the position P _n where the particle has moved is described. Since the data of the coordinate positions of the position P _n-1 and the position P _n are stored in the RAM 102 as described above, the vector v from the position P _{n -1} to the position P _n is used using these data. _n can be obtained.

Here 901 represents the viewpoint, (in the figure is indicated by v _e) line-of-sight direction vector of the viewpoint 901 are those operator can operate using the keyboard 104 or the mouse 105 or other device, Therefore, the CPU 101 manages it. Data of the line-of-sight vector of the viewpoint 901 being managed is stored in the RAM 102.

Therefore to calculate the cross product between the viewing direction vector v _e and the vector v _n, determine the normalized vector v _m in size resulting vector cross product results. More specifically determine the vector v _m according to the following formula.

v _m = v _e × v _n / | v _e × v _n |
The normalization process is performed for the purpose of simplifying the following process and is not essential. Vector v _m that was determined according to this formula is the vector of size 1 toward the width direction of the band polygon. Data of this vector _{v m} obtained are stored in the RAM 102.

Next, the cross product of the vector v _m and the vector v _n is calculated, and a vector v _l obtained by normalizing the result with the vector size of the cross product is obtained. More specifically, the vector v _l is obtained according to the following equation.

v _l = v _m × v _n / | v _m × v _n |
The normalization process is performed for the purpose of simplifying the following process and is not essential. The vector v _l obtained according to this equation is a vector of size 1 that goes in the normal direction of the belt polygon. The obtained data of the vector v _l is stored in the RAM 102.

And one side is produced in the RAM102 square polygon size 1 in a known manner, the polygon scaled in the direction of one side by the size of the vector v _n, predetermined direction perpendicular other side to the one side As a result of scaling by the width of the band-shaped object, a band polygon is obtained.

Then the strip polygons obtained, as shown in FIG. 9, it is parallel to one side vector v _n having a length of a vector v _n, and the width direction of the center position of the polygon to come on the vector v _n In addition, the normal direction of the band polygon is set to be the same as the direction indicated by the vector v ₁ .

By arranging the band polygon in this way, the surface of the polygon can be seen from the viewpoint 901, and the path from the position P _{n −1} to the position P _n can be shown in a band shape by the band polygon. .

It should be noted that any method can be used for generating the band polygon and arranging it as in the present embodiment, and any method can be used. As a result, as shown in FIG. It suffices if the surface of the band polygon can be seen and the path from the position P _{n −1} to the position P _n can be indicated by the band polygon.

  By performing such processing between the positions where the particles move, the movement trajectory of the particles can be expressed in a band shape by a plurality of polygons.

  FIG. 10 is a diagram showing a band-like object obtained by arranging band polygons between the positions where the particles have moved by the above-described processing and expressing the particle trajectory in a band shape as a result.

  In the figure, reference numeral 1000 denotes a trajectory of particle movement, and reference numerals 1001a, 1001b, 1001c, 1001d, 1001e, and 1001f denote particle movement positions (positions recorded in the table shown in FIG. 8). Each position is naturally on the locus 1000. When the band polygon arrangement processing described above is performed, the position 1001a and the position 1001b, the position 1001b and the position 1001c, the position 1001c and the position 1001d, the position 1001d and the position 1001e, the position 1001e, A band polygon can be arranged between the position 1001f and the position 1001f. Moreover, since each band polygon is arranged so that its surface can be seen from the viewpoint position, this band-like object is generated so that each surface can be seen from the viewpoint position.

  In addition, the arrangement processing of the belt polygon may be performed between the moved positions after the movement of the particles is finished due to the life span, or each time the particles move, the current position and the position immediately before the movement. You may make it perform between.

  In addition, for example, a texture of flame color is mapped to this band polygon, or a color such as red or yellow is added, and after the band polygon is arranged, the α value for the band polygon is gradually lowered with time. However, in that case, it can be expressed that the flame of that part gradually disappears. The generated band-like object is deleted when a predetermined time has elapsed.

  The process for generating the band-shaped object described above is also performed for the movement trajectory of other particles. That is, each moving position of each particle is recorded (that is, for each individual particle, a “data table indicating each moved position” shown in FIG. 8 is created in the RAM 102), and the recorded position data is recorded. A process for generating a band-like object that represents the movement trajectory of each particle in a band shape is performed.

  In this way, the movement trajectory of each particle can be expressed by a belt-like object. FIG. 11 is a diagram illustrating an example of an object obtained as a result of expressing the movement trajectory of each particle with a band-like object. Reference numeral 201 denotes a three-dimensional model of the above-mentioned candle, and reference numeral 1101 denotes an object obtained by expressing the movement trajectory of each particle with a band-like object. Further, since the lifespan of each particle varies depending on each particle to be generated, the length of the trajectory in which each particle moves, that is, the length of the belt-like object naturally varies.

  If the region where the object 1101 exists is to be filled only with particles, it can be easily understood that many are necessary. However, when a band-like object is used, since the surface is directed to the position of the viewpoint, the same region can be covered with a relatively small number. Further, since the band-like object is generated by the movement of one particle, the number of particles used as a result is smaller than that of the conventional one. Therefore, the calculation cost for calculating the behavior of each particle and the memory usage for managing the position of each particle can be further reduced.

  FIG. 12 is a flowchart of the flame object generation process according to the present embodiment described above. The program according to the flowchart of FIG. 10 is loaded from the external storage device 107 to the RAM 102 or from the storage medium to the RAM 102 by the storage medium drive device 108. The image processing apparatus according to this executes processing according to the flowchart of FIG. Note that some steps in the flowchart of the same figure are as described above, so that the description of such steps will be simplified.

  First, it is determined whether or not to newly generate particles in the initial generation region (step S1201). For example, it is generated with a higher probability when the number of particles that are still generated is small, and with a lower probability when the number of particles that are generated is large. Since the process of generating particles according to a given probability is a well-known technique, a description thereof is omitted here.

  If a new particle is to be generated, the process proceeds to step S1202, and a particle is generated at an arbitrary position randomly determined in the initial generation region (step S1202). Further, the velocity vector and the life span for this particle are determined. Setting is performed (step S1203). The set speed vector and survival data are recorded in the RAM 102 as described above. In addition, data on the initial position of the generated particles is also stored in the RAM 102.

  Next, the processing from step S1204 to step S1206 is performed for each generated particle. First, the position of the particle is moved by the above process (step S1204), the data of the moved position is recorded in the RAM 102 (step S1205), and the band polygon is arranged by the above process between the previous position and the current position. (Step S1207).

  If all the particles that have undergone the processing from step S1204 to step S1206 are performed (judgment processing in step S1207), the processing proceeds to step S1208, and the particles that have reached the set life span have elapsed since the occurrence. Is checked (step S1208). This is to check whether each particle has reached the end of its life by judging whether the result of counting after the generation of the particle has reached the lifetime set at the time of occurrence. be able to.

  Then, the particles that have reached the end of their lifetime are erased from the three-dimensional virtual space, and further, a process of erasing data relating to the particles from the RAM 102 is performed (step S1209).

  Then, the process returns to step S1201, and the subsequent processes are repeated.

  By the above process, the number of particles used to generate the flame object can be reduced, so that the calculation cost for calculating the behavior of the particles and the memory usage for managing the position of the particles are further reduced. be able to.

  In addition, since the band-like object is used in the present embodiment, an area that could not be filled without using innumerable particles can be filled with a small number of band-like objects. In addition, since only one particle is used to generate one band-like object, the number of particles used as a result can be reduced, and as described above, the calculation cost for calculating the behavior of particles, The amount of memory used for managing the position of the particles can be further reduced.

  In the flowchart shown in FIG. 12, the polygon is arranged every time the particle moves. However, when the path along which the particle has moved within its own life is determined, it has moved so far. In the case of a processing form in which band polygons are arranged between positions, processing according to a flowchart obtained by modifying the flowchart shown in FIG. 12 as follows may be performed.

  In other words, the process modified in step S1206 as follows may be performed immediately before the process in step S1209. In other words, when there is a particle that has reached the end of its life, processing is performed to place a band polygon between the positions using the data of the position of the particle that has been moved so far recorded in step S1205. Then, after the arrangement, the process of step S1209, that is, the erasure process of the particles and the data related to the particles is performed.

[Second Embodiment]
In the present embodiment, the movement direction of the particles by the gravity point is controlled based on an expression different from that in the first embodiment.

In the present embodiment, the parameter m _j for the gravity point j (j is an index attached to each gravity point), the parameter M _i for the particle i (i is an index attached to each particle), and the speed at the time of occurrence. Set in addition to vector and lifespan. It is assumed that the parameters m _j set for each gravity point can take different values. Further, the even the parameters M _i is set for the respective particles in which can take different respective values.

  In this case, if the distance between the gravity point j and the particle i is r, the force F that the particle i is attracted to the gravity point j is calculated according to the following equation.

F = k × M _i × m _j / (r × r)
Then, as in the first embodiment, calculation is performed according to this equation for all gravity points j in the vicinity of the position of the particle i, and the force vectors drawn for the respective gravity points are synthesized. Find the resulting force vector f.

  In this way, different values of parameters are set for each particle and each gravity point, and the force drawn for each gravity point is calculated using this parameter. Even if the number of gravity points used for the calculation is the same, each time Since a force vector having the same magnitude may not be obtained, more complicated behavior can be given to the particles.

In the present embodiment, (a + f / M _i ) is used instead of the acceleration a. That is, V = V + (a + f / M _i ) is calculated, and then X = X + V is calculated using the updated V.

Further, in the present embodiment, if M _i = m _j = 1 for all i and j, this embodiment is equivalent to the first embodiment.

  Further, depending on various parameters described in the first embodiment, the parameters may be changed dynamically. For example, the direction and magnitude of the acceleration vector may be dynamically changed without changing the acceleration vector to the same direction and the same size every time.

  In the above embodiment, the process for generating the flame object has been described. However, when the movement speed of the particles, the acceleration provided in advance, the movement speed of the gravity point, and the like are adjusted, the degree of divergence of the distance between the particles And moving speed will be different. Basically, however, these particle movements move with fluctuations. For example, the color of the band polygon or the color of the image mapped to the band polygon is made whitish, and the movement speed of each particle becomes slower. By doing so, as a result, a set of band-like objects can be expressed as smoke, and depending on the adjustment, it may appear as a fountain.

  Therefore, the essence of the processing described in the above embodiment is to generate a band-like object, and to express what has “fluctuation” in this set of band-like objects. Depending on the adjustment of the color of the belt polygon (including the case where the texture image is pasted), the technique described in the above embodiment can express an object other than the flame.

  Further, the above processing (for example, processing according to part or all of the flowchart shown in FIG. 12) is stored as a program in a storage medium such as a CD-R, ROM, DVD-ROM, MO, game cartridge, etc. The program stored in the storage medium is read (installed or copied) into the computer, and the computer or the CPU of the computer executes the program, whereby the computer can realize the above processing. Therefore, since the storage medium storing this program also enables the present invention, it is obvious that this storage medium is also within the scope of the present invention.

  In addition, the server device holds a program for the above processing (for example, processing according to part or all of the flowchart shown in FIG. 12), and supplies these to the computer via the network by a well-known technique. Can do. Since the CPU or MPU of the computer supplied with these programs and data can be used to realize the above processing, this server device can also be interpreted as the storage medium. Obviously, it is within the scope of the present invention.

  The storage medium may be other than a program or data provided to the computer from the outside, may be a memory chip incorporated in the computer, and the definition of the storage medium should be interpreted more widely. It is.

FIG. 2 is a block diagram illustrating a basic configuration of a computer that functions as an image processing apparatus that executes a process of generating a “flame object” according to the first embodiment of the present invention. It is a figure for demonstrating the initial generation area | region of the particle | grains used in order to produce | generate a flame object. It is a figure explaining the content set with respect to the particle in order to give a behavior to the particle generated in the initial generation area | region 201 shown in FIG. It is a figure which shows the mechanism for giving the behavior of "fluctuation" with respect to each generated particle. It is a figure for demonstrating the process which controls the moving direction of a particle by two gravity points 402a and 402b. It is a figure explaining the behavior given to each particle. It is a figure which shows the locus | trajectory of a movement of a certain particle (attention particle). It is a figure which shows the table which manages the data of each position where the attention particle moved memorize | stored in RAM102. It is a figure for demonstrating the process which produces | generates the strip | belt-shaped object which concerns on the 1st Embodiment of this invention. FIG. 5 is a diagram showing a band-like object obtained by arranging a belt polygon between positions where particles move and expressing the particle trajectory in a band shape as a result. It is a figure which shows the example of the object obtained as a result of expressing the locus | trajectory of the movement of each particle with a strip | belt-shaped object, respectively. It is a flowchart of the production | generation process of the flame object which concerns on the 1st Embodiment of this invention.

Claims (9)

An image processing apparatus that generates a flame object using a plurality of particles generated in a three-dimensional virtual space,
Setting means for setting an initial generation region of particles in the three-dimensional virtual space;
Initial value data recording means for recording initial movement direction and initial movement speed of particles generated in the initial generation region as initial value data;
First moving means for moving a virtual point generated periodically or irregularly at one end of a path preset in the three-dimensional virtual space in the direction of the other end of the path;
The data indicating the acceleration in a predetermined direction and the moving direction of the particles determined based on the initial value data are based on the positional relationship between the one or more virtual points moving on the path and the particles. A second moving means for moving the particles in the changed moving direction ;
Position recording means for sequentially recording data indicating each position of the particles moved by the second moving means;
A belt-like object generating means for generating a moving path of the particles as a belt-like object by disposing polygons between the positions indicated by the data recorded by the position recording means;
A plurality of data generated by performing the processing by the initial value data recording means, the second moving means, the position recording means, and the belt-like object generating means for each of a plurality of particles existing in the three-dimensional virtual space. An image processing apparatus, wherein a flame object is formed by a band-shaped object. An image processing apparatus that generates an object having fluctuation using a plurality of particles generated in a three-dimensional virtual space,
Setting means for setting an initial generation region of particles in the three-dimensional virtual space;
Initial value data recording means for recording initial movement direction and initial movement speed of particles generated in the initial generation region as initial value data;
First moving means for moving a virtual point generated periodically or irregularly at one end of a path preset in the three-dimensional virtual space in the direction of the other end of the path;
The data indicating the acceleration in a predetermined direction and the moving direction of the particles determined based on the initial value data are based on the positional relationship between the one or more virtual points moving on the path and the particles. A second moving means for moving the particles in the changed moving direction ;
Position recording means for sequentially recording data indicating each position of the particles moved by the second moving means;
A belt-like object generating means for generating a moving path of the particles as a belt-like object by disposing polygons between the positions indicated by the data recorded by the position recording means;
A plurality of data generated by performing the processing by the initial value data recording means, the second moving means, the position recording means, and the belt-like object generating means for each of a plurality of particles existing in the three-dimensional virtual space. An image processing apparatus, wherein an object having fluctuation is formed by a band-shaped object. An image processing method performed by an image processing apparatus that generates a flame object using a plurality of particles generated in a three-dimensional virtual space,
An initial value data recording step of recording the initial movement direction and initial movement speed of particles generated in the initial generation region in the three-dimensional virtual space in the memory of the image processing apparatus as initial value data;
A route setting step of reading data defining a route in the three-dimensional virtual space from the memory and using the read data to set the route in the three-dimensional virtual space;
A first movement step of moving a virtual point generated periodically or irregularly at one end of the route set in the route setting step toward the other end of the route;
Data indicating the acceleration in a predetermined direction and the moving direction of the particles determined based on the initial value data are based on the positional relationship between one or more virtual points moving on the path and the particles. A second moving step of moving the particles in the changed moving direction ,
A position recording step of sequentially recording data indicating each position of the particles moving in the second moving step in the memory;
A belt-shaped object generating step of generating a moving path of the particles as a belt-shaped object by arranging polygons between the positions indicated by the data recorded in the position recording step;
A plurality of data generated by performing the initial value data recording process, the second movement process, the position recording process, and the strip object generation process for each of a plurality of particles existing in the three-dimensional virtual space. An image processing method characterized in that a flame object is formed by a strip-shaped object.   4. The image processing method according to claim 3, wherein, in the initial value data recording step, data indicating a lifetime of particles generated in the initial generation region is included in the initial value data and recorded in the memory. . In the band-like object generation step, after data indicating each position where the particle has moved within the lifetime is recorded in the memory in the position recording step, a polygon is arranged between the positions indicated by the data, The image processing method according to claim 4 , wherein the movement path of the particles is generated as a band-like object. In the band-shaped object generating step, the particles move from the first position to the second position, and after the data indicating the second position is recorded in the memory in the position recording step, the first position and The image processing method according to claim 4 , wherein the process of arranging a polygon between the second position and the second position is performed every time the particle moves within the lifetime. The band-shaped object generation step further includes
A first calculation step of calculating a cross product of a line-of-sight direction vector of a viewpoint set in the three-dimensional virtual space and a vector in a movement direction between positions where particles move;
A second calculation step of calculating a cross product of a vector of the outer product result calculated in the first calculation step and a vector in the moving direction;
The direction indicated by the vector of the outer product result calculated in the second calculation step is a normal direction, and a polygon having a vector size in the movement direction is arranged between the positions in the movement direction. The image processing method according to any one of claims 3 to 6 . An image processing method performed by an image processing apparatus that generates an object having fluctuation using a plurality of particles generated in a three-dimensional virtual space,
An initial value data recording step of recording the initial movement direction and initial movement speed of particles generated in the initial generation region in the three-dimensional virtual space in the memory of the image processing apparatus as initial value data;
A route setting step of reading data defining a route in the three-dimensional virtual space from the memory and using the read data to set the route in the three-dimensional virtual space;
A first movement step of moving a virtual point generated periodically or irregularly at one end of the route set in the route setting step toward the other end of the route;
The data indicating the acceleration in a predetermined direction and the moving direction of the particles determined based on the initial value data are based on the positional relationship between the one or more virtual points moving on the path and the particles. A second moving step of moving the particles in the changed moving direction ,
A position recording step of sequentially recording data indicating each position of the particles moving in the second moving step in the memory;
A belt-shaped object generating step of generating a moving path of the particles as a band-shaped object by arranging polygons between the positions indicated by the data recorded in the position recording step;
A plurality of data generated by performing the initial value data recording process, the second movement process, the position recording process, and the strip object generation process for each of a plurality of particles existing in the three-dimensional virtual space. An image processing method, wherein an object having fluctuation is formed by a band-shaped object. A program causing a computer to execute the image processing method according to any one of claims 3 to 8 .

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