JP4068093B2 - Simulation apparatus, simulation method, and program - Google Patents

Description

  The present invention simulates the movement of a cloth-like body and an obstacle that does not intersect the cloth-like body in a virtual three-dimensional space, and approximately reproduces a situation where, for example, a skirt clings to a human foot. The present invention relates to a suitable simulation apparatus, a simulation method, and a program for realizing these on a computer.

Conventionally, in the field of 3D graphics, a technique for simulating an object whose shape changes dynamically, such as cloth, has been proposed. Such a technique is sometimes called cloth animation, and corresponds to a simulation of an actual physical phenomenon. For example, the technique is disclosed in the following documents.
Trowel, 3D motion algorithm, PART2 Human body and clothing model operating principle, C magazine September 2000 issue, pages 20-23, Softbank publishing, September 1, 2000 issue

  In such a technique, a single cloth is modeled with a plurality of mass points assumed to be arranged on the surface of the cloth and a spring connecting the mass points, and a differential equation or a difference equation is solved by numerical calculation. By applying the technique, the tension generated in the spring is calculated from the distance between the mass points, the movement of each mass point in a minute time is obtained by the tension, and the deformation of the cloth is simulated by moving the mass point.

  In [Non-Patent Document 1], the result of the simulation when the position constraint is imposed on a limited number of mass points (when the two corners of the upper end of the rectangular cloth are fixed) Is disclosed.

  However, in order to realize realistic three-dimensional graphics, a method of simulating the movement of a cloth-like body and an obstacle that does not intersect the cloth state, such as when a skirt cloth clings to a human foot. Is strongly demanded.

  On the other hand, according to the above modeling, a constraint condition that all or both of the mass point and the spring must not be included in the obstacle is imposed. Depending on the field that presents, there is a strong demand to enable high-speed simulation by an approximate method.

  The present invention has been made to solve the above-described problems, and simulates the movement of a cloth-like body and an obstacle that does not intersect the cloth-like body in a virtual three-dimensional space. It is an object of the present invention to provide a simulation apparatus, a simulation method, and a program for realizing these on a computer, which are suitable for approximately reproducing a situation clinging to a foot.

  In order to achieve the above object, the following invention is disclosed in accordance with the principle of the present invention.

  In the simulation device according to the first aspect of the present invention, a plurality of line-segment objects that expand and contract and a plurality of obstacle objects that should not intersect any of the plurality of line-segment objects are in a virtual three-dimensional space. The moving state is simulated, and a storage unit, a calculation unit, an update unit, a correction unit, and an output unit are provided and configured as follows.

  That is, the storage unit stores the position and speed information of the end points of the plurality of line-segment objects and the shape, position, speed, and posture information of the plurality of obstacle objects, and stores each of the end points. Any one of the plurality of obstacle objects is stored in association with the correction object.

  Here, the line segment object is a model of a spring, and the end point of the line segment object is a model of a mass point. Therefore, a cloth-like object is modeled by the line-like object and its end points. On the other hand, the obstacle object is a model of an object that can collide with the cloth-like object in the virtual three-dimensional space. For example, when the cloth-like object is a skirt cloth, the obstacle object corresponds to a human foot.

  In addition, as an obstacle object, the thing which deform | transforms can be considered besides the thing which does not deform | transform. For example, when modeling a human foot, divide one foot into three non-deformable internal objects, the thigh, shin, and ankle to toe, and connect them with joints to limit the degree of freedom, The external force and the internal force by the muscle model are transmitted.

  On the other hand, the calculation unit calculates the tension of the line-shaped object connecting the end points from the position and speed information of the end points stored in the storage unit, and the end points are determined by the calculated tension. The position to be moved after the minute time is calculated, and from the shape, position, speed and posture information of the obstacle objects stored in the storage unit, the obstacle object is moved after the predetermined minute time. The shape, position and orientation to be taken are calculated based on a predetermined rule.

  Since the line-shaped object is a model of a spring, if it becomes longer than the natural length (if the end points are moved away), a tension that pulls the end points occurs, and if it becomes shorter than the natural length (if the end points are closer) Negative tension (repulsive force) in the direction of separating the end points is generated. The simplest model is that the magnitude of this tension is proportional to the difference between the current length of the spring and its natural length, but for example, the repulsive force is used to simulate a wrinkled fabric. Can be generated at all times, or a very large repulsive force can be generated when the length exceeds a certain length in order to simulate a hard cloth, and various techniques can be used to determine the tension. it can.

  On the other hand, the obstacle object may be obtained by simulating the movement of the object in a general virtual three-dimensional space to obtain the position and orientation. In addition, when the obstacle object consists of a plurality of internal objects that do not deform, by calculating the external force and internal force, the constraint condition of the connection relationship, etc. in consideration of the connection relationship between the internal objects, It turns out how the obstacle object deforms.

  Further, the update unit stores the position where each of the plurality of end points is calculated to move after the minute time in the storage unit as the position and speed information of the end points of the line segment object, and The shape, position, and posture that each obstacle object should take after the minute time are stored in the storage unit as the shape, position, velocity, and posture information of the obstacle object, and the information stored in the storage unit is stored in the minute unit. Update to information after hours.

  As a result, the storage unit stores the shape, position, and orientation information of each object.

  Then, each time the update unit performs an update, the correction unit sets a part or all of the plurality of end points as correction targets, and the correction target end points are included in any of the plurality of obstacle objects. In the case of inclusion, the position of the included end point is associated with the end point according to the shape, position, speed, and posture information of the correction object stored in the storage unit. The corrected position is stored in the storage unit as the position and speed information of the end point, and the information stored in the storage unit is corrected.

  In the above example, the skirt does not go into the foot and the fabric stays on the surface of the foot. In order to simulate this, in the present invention, it is determined whether or not the line-shaped object connecting the end points (mass points) representing the shape of the cloth intersects the obstacle object representing the shape of the foot. . Here, various techniques as described later can be adopted to determine whether or not to “cross”.

  In the present invention, when the line-shaped object intersects with any obstacle object, the end point is moved to the vicinity of the surface of the correction object associated with the end point of the line-shaped object. The position is corrected so that they do not intersect.

  On the other hand, the output unit, based on the position and speed information of the end points of the plurality of line-shaped objects stored in the storage unit, and the shape, position, and posture information of the plurality of obstacle objects, Is generated and output at a predetermined cycle.

  Typically, the predetermined period is an interrupt period of a vertical synchronization signal of a television device or the like, and the generated image is temporarily stored in the frame memory, and the frame memory has a timing that matches the vertical synchronization interrupt. Information is converted into a signal for display on the screen and output.

  Further, when the predetermined period is at least twice as long as the predetermined minute time, and the update by the update unit is an update immediately before the output unit generates an image, the plurality of end points Are all corrected, and if the update by the updating unit is not the update immediately before the output unit generates an image, the correction is performed by correcting a part of the plurality of end points.

  As a result, correction processing requiring heavy calculation processing is performed for all end points immediately before screen display, etc., and for other end points, it is possible to perform more accurate simulation and calculation amount in a trade-off relationship. Make appropriate adjustments to reduce

  As described above, according to the present invention, it is possible to simulate, with an appropriate amount of calculation, how a cloth-like object collides with an object having a certain shape in a virtual three-dimensional space.

  Further, in the simulation apparatus of the present invention, for the integer m (2 ≦ m) and the integer i (1 ≦ i ≦ m), the predetermined period is (m + 1) times as long as the predetermined minute time. The plurality of end points are classified and stored in the storage unit into m groups from the first to the m-th, and the update immediately before the update unit generates an image (hereinafter, “ In the case of the i-th update counted from “0th update”), correction is performed using the end points classified into the i-th group and stored in the storage unit among the plurality of end points as correction targets. Can be configured.

  In the present invention, m groups for classifying end points are corrected once each in one cycle, and correction is performed for all end points immediately before screen display. Therefore, according to the present invention, it is possible to reduce the calculation amount while performing appropriate correction.

  Further, in the simulation apparatus of the present invention, for the integer m (2 ≦ m), the integer s, and the constant integer C, the predetermined period is not less than (m + 1) times the predetermined minute time. The plurality of endpoints are stored in the storage unit by being classified into m groups from the first to the m-th, and the update by the update unit is not the update immediately before the image is generated by the output unit, In the case of the s-th update, the correction is performed using the end points classified and stored in the storage unit as ((s + C) mod m) + the first group among the plurality of end points. can do.

  In the present invention, the m groups for classifying the end points are corrected with the same frequency, and all the end points are corrected immediately before the screen display. Therefore, according to the present invention, it is possible to reduce the calculation amount while performing appropriate correction.

  In the simulation apparatus of the present invention, the storage unit may classify each of the plurality of end points into a different group from the other end points adjacent to the end points via the line-shaped object. Can be configured to store.

  In the present invention, by classifying adjacent end points into different groups, the end point groups are dispersed as uniformly as possible. Therefore, according to the present invention, more accurate simulation can be performed while reducing the amount of calculation.

  Further, in the simulation apparatus of the present invention, the correction unit, for each of the end points to be corrected, the position and position of the correction object stored in the storage unit in association with the end point. When the correction object includes the speed and orientation information, the position of the end point before the update is moved by the same distance in the same direction as the movement of the correction object by the update, and the end point is updated. It can be configured such that the position of the end point is corrected at a position where a line segment connecting the subsequent position intersects the surface of the correction object.

  That is, if the end point (mass point, point placed on the surface of the cloth) is included inside the obstacle (the point on the surface of the cloth on the skirt has been sunk into the foot), the “intersection” is It is determined that it will occur.

  In the present invention, each of the obstacle objects and each of the end points are sequentially compared to determine whether or not they are included, and for each of the end points, the end point is set in advance to the end point. Since it is determined whether the object is included in the associated correction object (which is one of the obstacle objects) and “intersection” is determined, the calculation process can be performed at high speed, while the intersection is If it occurs, the position of the end point can be moved to an appropriate place.

  Further, in the simulation device of the present invention, the correction unit is configured such that, for each of the end points to be corrected, the positions of the end points are stored in the storage unit for the plurality of obstacle objects. When the position information is included in any of the plurality of obstacle objects, the position before the end point is updated by the same distance in the same direction as the movement of the correction object by the update, It can be configured such that the position of the end point is corrected at a position where a line segment connecting the updated position of the end point intersects the surface of the correction object.

  Also in the present invention, when the end points (mass points, points arranged on the surface of the cloth) are included inside the obstacle (the points on the surface of the cloth of the skirt are recessed in the foot), It is the same as described above that it is determined that an “intersection” occurs.

  In the present invention, each of the obstacle objects and each of the end points are sequentially compared to determine whether or not they are included, so that “intersection” is determined. While accurate intersection determination can be performed, when an intersection occurs, the position of the end point can be moved to an appropriate place.

  In the simulation apparatus of the present invention, when the shape of the correction object stored in the storage unit is a cylinder, the correction unit corrects the position of the end point associated with the correction object, and the center of the cylinder The position where the half line that starts from any point on the axis and intersects the surface of the cylinder perpendicular to the central axis and passes through the position of the end point before correction is the corrected position of the end point. It can be constituted as follows.

  The present invention discloses one method for determining the vicinity of an end point when the correction object is a cylinder. According to the present invention, the position of the end point can be easily corrected. .

  In the simulation apparatus of the present invention, when the shape of the correction object stored in the storage unit is a cylinder, the correction unit corrects the position of the end point associated with the correction object, and the center of the cylinder Starting from any point of the axis, a position where the half line perpendicular to the central axis and passing through the position of the end point before correction has advanced further by a predetermined minute distance from the position intersecting the surface of the cylinder The end point can be configured to be a corrected position.

  The present invention discloses one method for determining the vicinity of an end point when the correction object is a cylinder. According to the present invention, the position of the end point can be easily corrected. .

  In the simulation apparatus of the present invention, when the shape of the correction object stored in the storage unit is a polyhedron, and any one or more of the surfaces of the polyhedron is set as a correction surface, the correction unit is When correcting the position of the end point associated with the correction object, the position where the perpendicular line that is the closest to the end point among the planes set as the correction surface of the polyhedron intersects the side surface, It can be configured to be the corrected position of the end point.

  The present invention provides a method for determining the vicinity of an end point when a correction object is a polyhedron (a polyhedron having an arbitrary shape such as a concave polyhedron in addition to a convex polyhedron such as a rectangular parallelepiped, a prism, a truncated pyramid, and a regular polyhedron). The present invention is disclosed, and according to the present invention, the position of the end point can be easily corrected.

  In the simulation apparatus of the present invention, when the shape of the correction object stored in the storage unit is a polyhedron, and any one or more of the surfaces of the polyhedron is set as a correction surface, the correction unit is When correcting the position of the end point associated with the correction object, a position where a perpendicular line that is closest to the end point out of the planes set as the correction surface of the polyhedron intersects the correction surface The position further advanced by a predetermined minute distance from the position can be configured as the corrected position of the end point.

  The present invention provides a method for determining the vicinity of an end point when a correction object is a polyhedron (a polyhedron having an arbitrary shape such as a concave polyhedron in addition to a convex polyhedron such as a rectangular parallelepiped, a prism, a truncated pyramid, and a regular polyhedron). The present invention is disclosed, and according to the present invention, the position of the end point can be easily corrected.

  A simulation method according to another aspect of the present invention includes: a plurality of line-shaped objects that expand and contract; and a plurality of obstacle objects that should not intersect any of the plurality of line-shaped objects. It is executed by a simulation apparatus including a storage unit, a calculation unit, an update unit, a correction unit, and an output unit, and includes a calculation process, an update process, a correction process, and an output process, and is configured as follows. To do.

  Here, the storage unit stores the position and speed information of the end points of the plurality of line segment objects, and the shape, position, speed, and posture information of the plurality of obstacle objects. Each is stored in association with one of the plurality of obstacle objects as a correction object.

  In the calculation step, the calculation unit calculates the tension of the line-shaped object connecting the end points from the position and speed information of the end points stored in the storage unit, and the calculated tension The position where the end point should move after a predetermined minute time is calculated, and the obstacle object is determined from the shape, position, speed and posture information of the plurality of obstacle objects stored in the storage unit. The shape, position and posture to be taken after a minute time are calculated based on a predetermined rule.

  On the other hand, in the update step, the update unit stores the position calculated that each of the plurality of end points should move after the minute time in the storage unit as the position and speed information of the end points of the line segment object. The shape, position, and posture that each of the plurality of obstacle objects should take after the minute time are stored in the storage unit as the shape, position, velocity, and posture information of the obstacle object, and are stored in the storage unit. Information is updated to information after the minute time.

  Further, in the correction step, each time the update unit performs an update by the update unit, a part or all of the plurality of end points are set as correction targets, and the end points to be corrected are set as the plurality of obstacle objects. If it is included, the position of the included end point is associated with the end point, and the shape, position, speed, and speed of the correction object stored in the storage unit are stored. Based on the posture information, the corrected position is stored in the storage unit as the position and speed information of the end point, and the information stored in the storage unit is corrected.

  Then, in the output step, the output unit, from the position and speed information of the end points of the plurality of line segment objects stored in the storage unit, and the shape, position and orientation information of the plurality of obstacle objects, An image showing the state of the object is generated and output at a predetermined cycle.

  On the other hand, the predetermined period is twice or more the predetermined minute time.

  Further, in the correction process, when the update in the update process is an update immediately before the image is generated in the output process, the correction is performed on all of the plurality of end points, and the update by the update unit is performed by the output unit. If the update is not performed immediately before generation, correction is performed using a part of the plurality of end points as correction targets.

The program of the present invention can be recorded on a computer-readable information storage medium such as a compact disk, flexible disk, hard disk, magneto-optical disk, digital video disk, magnetic tape, and semiconductor memory.
The above program can be distributed and sold via a computer communication network independently of the computer on which the program is executed. The information storage medium can be distributed and sold independently from the computer.

  According to the present invention, a movement in a virtual three-dimensional space between a cloth body and an obstacle that does not intersect with the cloth body is simulated, and a situation in which, for example, a skirt clings to a human foot is approximately reproduced. Therefore, it is possible to provide a simulation apparatus, a simulation method, and a program that realizes these on a computer.

  Embodiments of the present invention will be described below. In the following, for ease of understanding, an embodiment in which the present invention is applied to an information processing device that operates as a game device will be described. However, information on various computers, PDAs (Personal Data Assistants), mobile phones, and the like is described. The present invention can be similarly applied to a processing apparatus. That is, the embodiment described below is for explanation, and does not limit the scope of the present invention. Therefore, those skilled in the art can employ embodiments in which each or all of these elements are replaced with equivalent ones, and these embodiments are also included in the scope of the present invention.

  FIG. 1 is an explanatory diagram showing a schematic configuration of a typical information processing apparatus in which the simulation apparatus of the present invention is realized. Hereinafter, a description will be given with reference to FIG.

The information processing apparatus 100 includes a CPU 101, a ROM 102, a RAM 103, an interface 104, a controller 105, an external memory 106, an image processing unit 107, a DVD-ROM drive 108, and a NIC (Network Interface Card). 109 and an audio processing unit 110.
A DVD-ROM storing a game program and data is loaded into the DVD-ROM drive 108 and the information processing apparatus 100 is turned on to execute the program, thereby realizing the simulation apparatus of the present embodiment. The

  The CPU 101 controls the overall operation of the information processing apparatus 100 and is connected to each component to exchange control signals and data. Further, the CPU 101 uses arithmetic operations such as addition / subtraction / multiplication / division, logical sum, logical product, etc. using an ALU (Arithmetic Logic Unit) (not shown) for a storage area called a register (not shown) that can be accessed at high speed. , Logic operations such as logical negation, bit operations such as bit sum, bit product, bit inversion, bit shift, and bit rotation can be performed. In addition, the CPU 101 itself is configured so that saturation operations such as addition / subtraction / multiplication / division for multimedia processing, vector operations such as trigonometric functions, etc. can be performed at a high speed, and those provided with a coprocessor. There is.

  The ROM 102 records an IPL (Initial Program Loader) that is executed immediately after the power is turned on, and when this is executed, the program recorded on the DVD-ROM is read out to the RAM 103 and execution by the CPU 101 is started. The The ROM 102 stores an operating system program and various data necessary for operation control of the entire information processing apparatus 100.

  The RAM 103 is for temporarily storing data and programs, and holds programs and data read from the DVD-ROM and other data necessary for game progress and chat communication. Further, the CPU 101 provides a variable area in the RAM 103 and performs an operation by directly operating the ALU on the value stored in the variable, or temporarily stores the value stored in the RAM 103 in the register. Perform operations such as performing operations on registers and writing back the operation results to memory.

  The controller 105 connected via the interface 104 receives an operation input performed by a user when executing a game such as an action game.

  The external memory 106 detachably connected via the interface 104 stores data indicating the play status (past results, etc.) of the battle game, data indicating the progress of the game, and chat communication log (record) associated with the battle. ) Is stored in a rewritable manner. The user can record these data in the external memory 106 as appropriate by inputting an instruction via the controller 105.

  A DVD-ROM mounted on the DVD-ROM drive 108 stores a program for realizing the game and image data, audio data, and moving image information data associated with the game. Under the control of the CPU 101, the DVD-ROM drive 108 performs a reading process on the DVD-ROM loaded therein, reads out necessary programs and data, and these are temporarily stored in the RAM 103 or the like.

The image processing unit 107 processes the data read from the DVD-ROM by an image arithmetic processor (not shown) included in the CPU 101 or the image processing unit 107, and then processes the processed data on a frame memory ( Buffering recording (not shown). The image information recorded in the frame memory is converted into a video signal at a predetermined synchronization timing and output to a monitor (not shown) connected to the image processing unit 107. Thereby, various image displays are possible. Such processing of the image processing unit 107 can be performed in parallel with the arithmetic processing of the CPU 101.
The image calculation processor can execute a two-dimensional image overlay calculation, a transmission calculation such as α blending, and various saturation calculations at high speed.

Also, polygon information arranged in the virtual three-dimensional space and added with various texture information is rendered by the Z buffer method, and the polygon arranged in the virtual three-dimensional space from the predetermined viewpoint position is determined in the direction of the predetermined line of sight It is also possible to perform high-speed execution of operations for obtaining rendered images.
Further, the CPU 101 and the image arithmetic processor operate in a coordinated manner, so that a character string can be drawn as a two-dimensional image in a frame memory or drawn on the surface of each polygon according to font information that defines the character shape. is there. The font information is recorded in the ROM 102, but it is also possible to use dedicated font information recorded in the DVD-ROM.

  In addition, the moving image information recorded on the DVD-ROM and the moving image information when this is transferred to the RAM 103 or the like in advance are superimposed on a predetermined area of the screen by the image processing unit 107, Movie display can be performed.

  The NIC 109 is used to connect the information processing apparatus 100 to a computer communication network (not shown) such as the Internet, and is used in configuring a LAN (Local Area Network). 10BASE-T / 100BASE- Connect to the Internet using an analog modem, ISDN (Integrated Services Digital Network) modem, ADSL (Asymmetric Digital Subscriber Line) modem, or cable television line to connect to the Internet using a telephone line. For example, and an interface (not shown) that mediates between them and the CPU 101.

  The current date and time information can be obtained by connecting to an SNTP server in the Internet via the NIC 109 and obtaining information therefrom. In addition, various network game server devices may be configured and configured to perform the same functions as the SNTP server.

The audio processing unit 110 converts audio data read from the DVD-ROM into an analog audio signal, and outputs the analog audio signal from a speaker (not shown) connected thereto. Further, under the control of the CPU 101, sound effects and music data to be generated during the progress of the game are generated, and sound corresponding to this is output from the speaker.
When the audio data recorded on the DVD-ROM is MIDI data, the audio processing unit 110 refers to the sound source data included in the audio data and converts the MIDI data into PCM data. If the compressed audio data is in ADPCM format or Ogg Vorbis format, it is expanded and converted to PCM data. The PCM data can be output by performing D / A (Digital / Analog) conversion at a timing corresponding to the sampling frequency and outputting it to a speaker.

  Furthermore, a microphone 111 can be connected to the information processing apparatus 100 via the interface 104. In this case, the analog signal from the microphone 111 is subjected to A / D conversion at an appropriate sampling frequency so that processing such as mixing in the sound processing unit 110 can be performed as a PCM format digital signal. When the information processing apparatus 100 is used as a game apparatus, voice data input from the microphone 111 can be used as instruction input data as an input device instead of the controller 105.

  In addition, the information processing apparatus 100 uses a large-capacity external storage device such as a hard disk so as to perform the same function as the ROM 102, the RAM 103, the external memory 106, the DVD-ROM mounted on the DVD-ROM drive 108, and the like. You may comprise.

  Further, it is possible to adopt a form in which a keyboard for accepting a character string editing input from a user, a mouse for accepting various position designations and selection inputs, and the like are connected. In addition, a general-purpose personal computer can be used instead of the information processing apparatus 100 of the present embodiment.

Similar to the information processing apparatus 100, a general computer includes a CPU, RAM, ROM, DVD-ROM drive, and NIC, and includes an image processing unit that is not necessarily specialized for screen display in a game. In addition to having a hard disk as a storage device, a flexible disk, a magneto-optical disk, a magnetic tape, or the like is generally available. In addition, a keyboard, a mouse or the like is used as an input device instead of a controller.
Therefore, it is possible to operate such a general computer as the simulation apparatus of the present invention.

  FIG. 2 is a schematic diagram illustrating a schematic configuration of the simulation apparatus according to the embodiment of the present invention. Hereinafter, a description will be given with reference to FIG.

  The simulation apparatus 201 simulates the movement of a plurality of line-segment objects that expand and contract and a plurality of obstacle objects that should not intersect any of the plurality of line-segment objects in a virtual three-dimensional space. A storage unit 202, a calculation unit 203, an update unit 204, a correction unit 205, and an output unit 206.

  The storage unit 202 stores the position and speed information of the end points of the plurality of line-segment objects and the shape, position, speed, and posture information of the plurality of obstacle objects, and each of the plurality of end points includes: One of the plurality of obstacle objects is stored in association with the correction object.

  FIG. 3 is an explanatory diagram showing the state of the line segment object and its end points.

  As shown in FIG. 3, as a cloth-like object model 301, a line-like object 302 that behaves like a spring is connected in a mesh shape. Then, the end point 303 to be combined is set as a mass point. When the end points 303 are evenly distributed, the mass obtained by dividing the mass of the cloth-like object by the total number of end points 303 may be the mass of each end point 303.

  The position of each mass point when the cloth-like object is in a natural state (a state where no external force is applied) is determined, and the distance between the mass points (end points) at that time is defined as the natural length of the line-shaped object 302. Accordingly, it is possible to model a cloth having a three-dimensional shape (for example, a shape having wrinkles or folds) by appropriately adjusting the natural length.

  FIG. 3A shows a technique in which the mass points (end points 303) are arranged at the vertices of the equilateral triangle mesh, and the line segment objects 302 are arranged on the sides of the equilateral triangle. Note that, as in the area division used in the finite element method or the like, it is not always necessary to use a regular triangle as a triangular shape, and there are cases where a regular triangle cannot be adopted near the edge of a cloth-like object. In such a case, it is desirable to adopt a shape that is as close to an equilateral triangle as possible (a shape that is not elongated).

  FIG. 3B shows a technique in which mass points (end points 303) are arranged at lattice points, and line segment objects 302 are arranged on the sides of a square mesh whose lattice points are the vertices. In the methods of FIGS. 3A and 3B, since most of the line-shaped objects 302 have the same length, it is possible to simplify the calculation.

  FIG. 3C is a method of arranging the line segment object 302 on the diagonal of the square mesh in addition to the method of FIG. 3B. In this method, since two types of line-segment objects 302 having different lengths are used, calculation is slightly complicated, but more natural cloth deformation can be expressed.

  Since the line-shaped object 302 is a model of a spring, in the simplest method, when it extends beyond the natural length, the end points are pulled by a tension proportional to the extension length, and it shrinks below the natural length. In this case, a force acts in a direction in which the end points are moved away by a repulsive force (negative tension) proportional to the contraction length.

  As described above, the line segment object 302 models a spring, and the end point 303 of the line segment object 302 models a mass point. Therefore, a cloth-like object is modeled by the line-shaped object 302 and its end points 303.

  On the other hand, the obstacle object is a model of an object that can collide with the cloth-like object in the virtual three-dimensional space. For example, when the cloth-like object is a skirt cloth, the obstacle object corresponds to a human foot.

  FIG. 4 is an explanatory diagram illustrating a relationship between an obstacle object and a line-shaped object in the virtual three-dimensional space. FIG. 4A shows a state in which an object shaped like a leg and a line segment object are arranged in a virtual three-dimensional space, and FIG. 4B shows an object shaped like a leg. Is represented by an obstacle object having a simpler shape.

  As shown in the figure, a human thigh 412, a knee joint 413, a shin 414, an ankle joint 415, and an ankle to toe 416 are a quadrangular prism obstacle object 402a and a ball obstacle, respectively. It is represented by a physical object 402b, a cylindrical obstacle object 402c, a spherical obstacle object 402d, and a trapezoidal obstacle object 402e.

  For these five obstacle objects 402, the center of the bottom surface of the quadrangular prism 402a is in contact with the sphere 402b, the center of the bottom surface of the cylinder 402c is in contact with the sphere 402b and the sphere 402d, and a predetermined point on the upper surface of the trapezoidal body 402e is a sphere. The human foot is simulated by exercising under the restraint condition of touching 402d. In addition, in order to simulate the foot, the force applied to each part and the force to bend and stretch the knee and ankle are designed by various muscle models so that internal force and various external forces are transmitted, A simulation can be performed. Various known techniques can be applied to such a physical simulation of the human body.

  As shown in the figure, a cloth-like object model 301 constituted by a line segment object 302 and its end point 303 is arranged outside the obstacle object 402.

  The end point 303 of the line-shaped object 302 should not be sunk into the obstacle object 402, just as the skirt fabric does not sunk into the human foot.

  On the other hand, when thinking about actually drawing a cloth-like object in three-dimensional graphics, the distance between the vertex (end point 303) of each mesh and the obstacle object 402 is determined, and which one is in front is checked. Then, the texture is pasted on the mesh by the Z buffer method.

  Therefore, even if a part of the line segment of the line segment object 302 is sunk into the surface of the obstacle object 402, there is often no practical problem. In this case, it is sufficient to make the mesh fine enough to simulate the cloth-like object with the required accuracy.

  As described above, in the following embodiment, “the intersection of the line-shaped object 302 and the obstacle object 402” is described as “one of the end points of the line-shaped object 302 is included in the obstacle object 402”. It shall be handled as a thing. Details thereof will be described later.

  However, depending on the application field, it is better to define “does not intersect” by the fact that the entire line segment object 302 is always outside the obstacle object 402 (at least in contact with the surface of the obstacle object 402). Sometimes. Such a case will also be described later.

  In the above description, the five parts from the human thigh, knee joint, shin, ankle, and ankle to the tiptoe are treated as the five obstacle objects 402, but these are transformed into one. It may be handled as the obstacle object 402. That is, one obstacle object 402 is composed of a plurality of (simple-shaped) internal objects connected by a condition that restricts the degree of freedom, and each internal object is based on various muscle models or the like. The internal force is transmitted and deformed.

  As described above, the storage unit 202 stores position information, speed information, posture information, shape information, and the like of various objects, and also stores various information necessary for physical simulation of various objects. Is done. An instruction input from the user via the controller 105 is also temporarily stored in the storage unit 202. The calculation unit 203 described later refers to the stored information. Therefore, in the present embodiment, the RAM 103 functions as the storage unit 202.

  FIG. 5 is a schematic diagram showing a flow of control of simulation processing in the present embodiment. Hereinafter, a description will be given with reference to FIG.

  First, under the control of the CPU 101, initial values of various types of information are set in the storage unit 202 (step S501). These initial values may be read from a DVD loaded in the external memory 106 or the DVD-ROM drive 108, or may be set by an instruction input from the user via the controller 105.

  On the other hand, the calculation unit 203 calculates the tension of the line-shaped object 302 connecting the end points 303 from the position information of the end points 303 stored in the storage unit 202 (step S502).

Here, the natural length of the line-shaped object 302 is L, the coordinates of the end point 303 to be considered in the virtual three-dimensional space 401 are (x ₁ , y ₁ , z ₁ ) and (x ₂ , y ₂ , z ₂ ), If the spring constant of the line segment object 302 is k, according to one of the simplest spring models, the magnitude F of the tension of the line segment object 302 can be expressed as follows.
F = k (D-L)
However, D is the length of the current line-shaped object 302 and can be calculated as follows.
D = ((x ₂ -x ₁ ) ² + (y ₂ -y ₁ ) ² + (z ₂ -z ₁ ) ² ) ^1/2

Therefore, the mass point (end point 303) at the coordinates (x ₁ , y ₁ , z ₁ ) receives a force expressed by the following vector.
(F (x ₂ -x ₁ ) / D, F (y ₂ -y ₁ ) / D, F (z ₂ -z ₁ ) / D)

On the other hand, the mass point (end point 303) at the coordinates (x ₂ , y ₂ , z ₂ ) receives a force expressed by the following vector.
(-F (x ₂ -x ₁ ) / D, -F (y ₂ -y ₁ ) / D, -F (z ₂ -z ₁ ) / D)

  When the magnitude F of the tension is positive, it means that the spring pulls the end points, and when the tension is negative, the spring pulls the end points apart.

  The modeling of the tension generated by the spring is not limited to the above form, and various methods can be employed. For example, when D exceeds a certain upper limit or falls below a certain lower limit, F also takes a predetermined constant, or the tension is calculated by a more complicated calculation rather than a mere proportion. The relationship between D and F may not be changed continuously in proportion, but may be discontinuously changed stepwise.

  Next, the calculation unit 203 calculates the external force applied to the end point 303 by taking the sum of the calculated tensions for each end point 303 (step S503), and the end point 303 is moved after a predetermined minute time by the external force. The position to be calculated is calculated (step S504). As described above, the force applied to each mass point (end point 303) can be found by calculating the tension for each line segment object 302 and taking the sum of the tensions.

  For example, in the case of the model shown in FIG. 3A, since six line segment objects 302 are gathered at a representative mass point (end point 303), the sum of these six tensions is obtained. In the case of FIG. 3B, since four line-like objects 302 are gathered, the sum of these four tensions is obtained. In the case of FIG. 3C, since eight line-like objects 302 are gathered, the sum of these eight tensions is obtained.

  In addition, when an external force is applied to the mass point (end point 303), the force is also counted. As the external force, for example, gravity or wind force can be considered. If the mass of the mass point (end point 303) is m and the gravitational acceleration vector is g, gravity is mg.

The force vector applied to a certain mass point (end point 303) is f, and the position vector based on the position information of the mass point (end point 303) stored in the current storage unit 302 is r (corresponding to the coordinates of the end point 303). .), When the velocity vector based on the velocity information is v and the predetermined minute time is dt, the position vector r ′ representing the position where the end point 303 should move after the predetermined minute time and the end point 303 after the predetermined minute time The velocity vector v ′ representing the velocity of can be expressed most simply as follows.
v '= v + f · dt / m;
r '= r + (v + v') ・ dt / 2
= r + v ・ dt + f ・ dt ² / (2m)

  This is the simplest configuration of integration using a computer, and a technique such as the Runge-Kutta method can be applied to perform more detailed simulation.

  Here, when the result of this simulation is displayed on a screen in a game, it is desirable that this minute time dt is proportional to the refresh rate of the screen display. For example, in a general game device, since vertical synchronization occurs at 60 Hz, the minute time dt is a time obtained by further dividing 1/60 seconds by an integer.

  Next, the calculation unit 203 calculates the shape that the obstacle object 402 should take after the predetermined minute time from the shape, position, speed, and posture information of each of the plurality of obstacle objects 402 stored in the storage unit. The position and orientation are calculated based on a predetermined rule (step S505).

  The force applied to the obstacle object 402 is obtained, and the same calculation as in the case of the mass point (end point 303) may be performed. On the other hand, the obstacle object 402 may be obtained by simulating the movement of the object in a general virtual three-dimensional space to obtain the position and orientation. If the obstacle object 402 is composed of a plurality of internal objects that are not deformed, each position can be obtained by calculating external force, internal force, constraint conditions of the connection relationship, etc. in consideration of the connection relationship between the internal objects. And how the obstacle object 402 is deformed.

  In the above calculation, the case where the obstacle object 402 and the end point 303 can freely move is considered, but there are cases where these are constrained. For example, the upper edge of the skirt is fixed to the human waist, and the two vertices next to the flag are fixed to the pole. Therefore, when there are such constraint conditions, the result of solving the differential equation is corrected, or the next position is determined without solving the differential equation. Known techniques can be employed for such correction and determination techniques.

  As described above, the CPU 102 functions as the calculation unit 203 in cooperation with the RAM 103. Note that the calculation related to the line segment object 302 in step S502 to step S504 and the calculation related to the obstacle object 402 in step S505 can be performed for each object independently, and thus can be vectorized. Therefore, various methods such as a method in which the CPU 102 directly performs calculation repeatedly, a method in which calculation is performed in parallel using a vectorization command or a multimedia command, and a method in which a parallel numerical arithmetic coprocessor is used can be employed.

  Now, the update unit 204 causes the storage unit 202 to store, as position information of the end point 303 of the line segment object 302, the position where each of the plurality of end points 303 is calculated to move after the minute time ( In step S506, the shape, position, and posture that each of the plurality of obstacle objects 402 should take after the minute time are stored in the storage unit 202 as shape, position, velocity, and posture information of the obstacle object 402 ( Step S507), the information stored in the storage unit 202 is updated to the information after the minute time.

  As a result, the storage unit 202 stores the shape, position, and orientation information of each object.

  At this stage, only a simple physical simulation is performed when the time has elapsed by the minute time dt. Therefore, according to the values stored in the storage unit 202, the line segment object 302 and the obstacle It is possible that the object 402 is “intersecting”. That is, a mass point (end point 303) may be embedded in the obstacle object 402. Therefore, the function of the correction unit 205 is to correct the position of the mass point (end point 303).

  For each mass point (end point 303), the correction unit 205 repeats the following processing from step S508 to step S512 (step S508). First, one repetitively unprocessed mass point (end point 303) of this time is acquired (step S509), and it is determined whether or not the end point 303 is embedded in an obstacle (step S510).

Specifically, the following two methods (a) and (b) can be considered.
(A) The position of the end point 303 and each of the plurality of obstacle objects 402 are compared to determine whether the end point 303 is included in any of the obstacle objects 402.

This is suitable when the number of obstacle objects is small, and it is possible to more appropriately determine whether or not to intersect.
(B) The position of the end point 303 and the object stored in the storage unit 202 to be associated with the end point 303 among the plurality of obstacle objects 402 (hereinafter referred to as the associated obstacle object 402 Is referred to as “correction object”), and it is determined whether or not the end point 303 is included in the correction object.

  Typically, one correction object is associated with one end point 303. When a plurality of obstacle objects 402 are to be associated with one end point 303, one obstacle object having the plurality of obstacle objects 402 to be associated as an internal object is used as a correction object, and the correction object is used. The object may be deformed.

  For example, as can be seen from the situation where the fabric of the skirt clings to the foot, a certain area of the skirt clings to the thigh, a certain area to the knee, and a certain area to the shin. Therefore, in such a situation, the correction object of the mass point (end point 303) of the region clinging to the thigh may be associated with the obstacle object 402 having a quadrangular prism.

  The methods (a) and (b) may be appropriately selected according to the field of use.

  Then, when it is determined that the vehicle intersects, that is, the end point 303 is indented into the obstacle (step S510; Yes), the position information of the end point 303 is changed to the shape, position, speed, and the correction object. It correct | amends by attitude | position information (step S511), memorize | stores the positional information of the corrected result in the memory | storage part 202 (step S512), and returns to step S508.

Here, the correction method will be specifically described. A typical method is as follows.
(1) The position of the end point 303 is moved to the point closest to or near the end point 303 on the surface of the correction object.
(2) Considering a coordinate system fixed to the correction object, the path of change of the position of the end point 303 in the minute time moves to or near the point where it intersects the surface of the correction object.
Hereinafter, it demonstrates in order.

  First, the method (1) has an advantage that the position of the correction destination can be easily obtained particularly when the correction object has a simple shape.

  FIG. 6 is an explanatory diagram showing the relationship among the correction object, the position before correction of the end point 303, and the position after correction when the correction object has various shapes in the method (1).

  As shown in FIG. 5A, when the correction object 601 is a sphere, a half line passing through the position 602 before correction of the end point 303 is extended from the center 611 of the sphere, and a point 603 where this intersects the spherical surface is obtained. The corrected position may be used. Alternatively, a point 604 further advanced by a predetermined minute distance α from the intersection in the spherical surface may be set as the corrected position.

  In this figure (b), the case where the object for correction is a polyhedron (including various rectangular parallelepipeds, cubes, regular polyhedrons, prisms, pyramids, trapezoids, etc.) is considered. In this case, a perpendicular line 613 is dropped on each surface 612 of the polyhedron from the position 602 before correction of the end point 303, and the foot of the perpendicular line 613 with respect to the surface 612 where the perpendicular line 613 is the minimum distance, that is, the intersection of the perpendicular line 613 and the surface 612. May be the corrected position. Alternatively, a point 604 further advanced by a predetermined minute distance α from the intersection 603 between the perpendicular line 613 and the surface 612 that is the minimum distance may be set as the corrected position.

  In this figure (c), the case where the object for correction | amendment is a cylinder is considered. In this case, the half line 615 starting from one point of the center axis 614 of the cylinder, which is perpendicular to the center axis 614 and passes through the end point 303, and the intersection 603 of the cylinder surface with the corrected position Just do it. Alternatively, the corrected point may be a point 604 where the half line 615 is further advanced from the intersection 603 by a predetermined minute distance α.

  The predetermined minute distance α employed here is preferably smaller than the mesh size of the cloth-like object. That is, it is preferable to set a value smaller than the natural length of each line segment object 302.

  Next, since the method (2) tracks the movement of the end point 303 based on the physical model and sets the intersection where the path intersects with the correction object as the corrected position, there is an advantage that the most likely result is obtained. is there.

  In order to implement the method (2) frankly, first, consider a moving coordinate system fixed to the correction object 601. In general, the moving coordinate system moves and rotates before and after the update with respect to the global coordinate system.

  Next, consider how the end point 303 moves before and after the update in the moving coordinate system. Since the moving coordinate system moves and rotates with respect to the global coordinate system, and the end point 303 moves with respect to the global coordinate system, the end point 303 moves and rotates within the moving coordinate system. Become.

  However, it is often difficult to obtain the intersection 603 where the trajectory that moves and rotates intersects the correction object 601. Therefore, a method is adopted in which rotation is ignored and only the movement of the center of gravity (or the center or a predetermined representative point) of the correction object 601 and the movement of the end point 303 are considered, and the moving coordinate system is not rotated. May be. That is, the correction object 601 is approximated as being moved in parallel.

  FIG. 7 is an explanatory diagram showing a concept when such a method is adopted in the method (2).

  In this method, since the correction object 601 is approximated as moving in parallel, a vector representing the movement in the global coordinate system is set to w.

  This figure shows a state in which a cylinder is considered as the correction object 601 and each object is projected in parallel in the central axis direction of the cylinder. Therefore, in this figure, the correction object 601 is displayed as a circle before (indicated by a solid line in this figure) and after the movement (indicated by a broken line in this figure).

  On the other hand, the end point 303 has moved from the position r to r ′ in the global coordinate system. This position r ′ is inside the correction object 601 after movement.

  Here, if it is assumed that the end point 303 has moved in parallel with the correction object 601, the movement destination is r + w in the global coordinate system. This position r + w is outside the correction object 601 after movement.

  Therefore, a line segment 621 connecting the position r + w and the position r ′ in the global coordinate system is considered. Since the line segment 621 connects the outside and the inside of the correction object 601, the line segment 621 must always have an intersection 603 that intersects the correction object 601. Therefore, the intersection point 603 is set as a corrected position.

  Further, a half line 622 starting from the position r + w and passing through the position r ′ is considered, and a point 604 where the half line 622 further advances from the intersection 603 by a predetermined minute distance α may be set as a corrected position.

  As a method for obtaining the intersection 603 between the line segment 621 and the correction object 601 and the further advanced point 604, various three-dimensional geometric techniques in known three-dimensional graphics can be applied.

  Note that when the correction object 601 also changes its orientation, the line segment 621 may not have the intersection 603 with the correction object 601. At that time, a point closest to r ′ or an α vicinity thereof may be set as a corrected position among the intersections 603 of the straight line obtained by extending the line segment 621 and the correction object 601.

  As described above, when there are various arithmetic coprocessors, the CPU 102 cooperates with the coprocessor and also with the RAM 103 to function as the correction unit 205.

  In addition, when searching for the intersection 603 among the surfaces of the correction object 601, there may be a method in which only the correction surface is considered instead of considering all surfaces.

  In the above description, even if the correction object 601 is a finite-length cylinder, the intersection of the infinite-length cylinder side surface including the side surface with a line segment, a half line, or the like is not taken into consideration. However, this is nothing but the fact that the infinitely long cylindrical side surface is used as the correction surface.

  When the parts of a human foot are represented by a cylinder, the ceiling and floor portions correspond to the inside of the human foot, and thus are not suitable as corrected positions. Therefore, the side surface of an infinitely long cylinder obtained by extending the side surface of a finite length infinitely is used as a correction surface.

  When the correction object 601 is a polyhedron, if the number of faces is too large, a polyhedron with a smaller number of faces that approximates the correction object 601 is considered, and the surface of the approximate polyhedron with a smaller number of faces is corrected. It is a use surface.

  As the approximate polyhedron, for example, a polyhedron circumscribing the correction object 601 may be employed, or a surface in which the surface of the approximate polyhedron and the surface of the correction object 601 appropriately intersect may be employed.

  In addition, a new polyhedron obtained by deleting any one of the surfaces of the correction object 601 as appropriate and expanding the remaining surface as it is may be used as an approximate polyhedron.

  Now, after updating (step S507) and correction (steps S508 to S512) of the position information and the like of each end point 303 by such processing, between the previous update / correction and the current update / correction, It is determined whether a vertical synchronization interrupt has occurred (step S513).

  If it occurs (step S513; Yes), the output unit 206 stores the position information of the end points 303 of the plurality of line segment objects 302 stored in the storage unit 202, the shape, the position of the plurality of obstacle objects 402, and From the posture information, an image showing the state of these objects is generated and output to the frame memory (step S514). By performing the processing in this way, a three-dimensional graphics image is generated and stored in the frame memory at the same cycle as the vertical synchronization interrupt.

  The image information stored in the frame memory is converted into a video signal at the period of the vertical synchronization interrupt and output to a monitor connected to the image processing unit 107. As a result, the state of the virtual three-dimensional space generated by the simulation apparatus 201 is displayed as an animation on the screen.

  After the process of step S514 is completed or when a vertical synchronization interrupt has not occurred (step S513; No), the elapsed time from step S502, which is the start point of the current iteration, is acquired, and the elapsed time is the predetermined time. Wait until the minute time dt is reached (step S515), and return to step S502. During the waiting time, for example, other necessary processing such as checking an instruction input from the user can be appropriately executed.

  As a result, the minute time dt becomes equal to the time interval for updating by the updating unit 204 (that is, the time interval for correcting by the correcting unit 205), and is stored in the storage unit 202 as the actual time elapses. The shape, position, speed, and posture information of the object to be changed will change. Therefore, if the screen display is performed for each vertical synchronization interrupt, it is possible to present the movement of each object in the virtual three-dimensional space in the same way as in the real world.

  As described above, in the present embodiment, it is possible to simulate a state in which a cloth-like object collides with an object having a certain shape in a virtual three-dimensional space.

  In the above description, the process of correcting the position of the end point 303 (steps S508 to S512) is always performed for all end points 303. However, calculation of the position correction of the end point 303 is generally a heavy process. In the following, a technique for successfully omitting the position correction process will be described.

  That is, when the update by the update unit 204 is an update immediately before an image is generated by the output unit 206, the correction unit 205 sets all of the end points as correction targets; otherwise, the correction unit 205 corrects some of the end points. It is targeted.

  The following can be considered as a method for selecting a part of the end points. First, it is assumed that the minute time dt is equal to 1 / (m + 1) times the vertical synchronization interrupt cycle (m is an integer of 2 or more).

  Then, the end points 303 are classified into m groups. At this time, it is desirable to classify the end points 303 adjacent to each other via the line-shaped object 302 so as to belong to different groups as much as possible. The end point 303 may be included in a plurality of groups.

  Further, it is desirable that the end points 303 included in the i (1 ≦ i ≦ m) -th group are dispersed as uniformly as possible in the cloth-like object modeled by the end points 303. When dt is determined as described above, the update is performed m + 1 times during one vertical synchronization period.

  FIG. 8 is a flowchart showing the flow of control when such processing is performed. Since this control flow is often the same as that shown in FIG. 5, the same step numbers are used for the common parts. In the following description, the changed parts are mainly shown, and most of the common parts are not shown.

  First, in the initialization in step S501, an appropriate integer constant C is set in the integer counter variable s prepared in the RAM 103 (step S501).

  Then, after updating the information such as the position of the end point 303 of the line-shaped object 302 and the information such as the position of the obstacle object 402 (steps S502 to S507), the previous update, the current update, During this period, it is determined whether a vertical synchronization interrupt has occurred (step S801).

  If it has occurred (step S801; Yes), the same correction processing as in steps S508 to S512 is performed on all end points 303 as processing targets (step S802). Further, the output unit 206 outputs the 3D graphics image information (step S514), waits (step S515), and returns to step S502.

  On the other hand, if it has not occurred (step S801; No), the same correction processing as that in steps S508 to S512 is performed on only the end point 303 belonging to (s mod m) + 1st group (step S803). . Here, s mod m means the remainder when s is divided by m.

  Then, the value of the counter variable s is increased by 1 (step S804), and the process proceeds to step S515.

  As a result, correction for each group is performed once (total m times) during one vertical synchronization period, and correction for all end points is performed once immediately after the vertical synchronization interrupt occurs. Become.

  Note that dt does not necessarily have to be 1 / (m + 1) times the vertical synchronization period. In this case, correction processing for each group is performed equally according to the value of the counter variable s.

  In this aspect, by appropriately thinning out the correction process, the CPU time can be devoted to other processes, while the correction is performed for all end points immediately before image output, so that the end points are trapped in obstacles. Does not occur. Therefore, it is possible to perform a simulation that appropriately takes into account the trade-off between calculation amount and accuracy.

  In an example of the above embodiment, only the movement amount of the representative point (centroid, center, etc.) of the correction object is considered, and the end point movement locus with respect to the correction object is not considered without considering the rotation amount of the correction object. Then, the intersection of the locus and the surface of the correction object is obtained, and the position of the end point is moved to the intersection.

  This embodiment employs the same configuration as that of the above embodiment, but differs in that the amount of rotation of the correction object is also taken into account when obtaining the intersection.

  FIG. 9 is an explanatory diagram for explaining how to obtain the intersection point in the above embodiment and this embodiment. In this figure, each movement amount and rotation amount are exaggerated for easy understanding.

  FIG. 9A shows the movement of the end point 303 and the correction object 601. As shown in FIG. 9A, the position 901 before the end point 303 is moved is outside the position 911 before the correction object 601 is moved. Further, the position 902 after the movement of the end point 303 is included in the position 912 after the movement of the correction object 601. The correction object rotates at a position 911 before and after the movement of the correction object 601. In order to facilitate understanding, the position before movement is indicated by a solid line, and the position after movement is indicated by a one-dot broken line.

  FIG. 9B shows how to obtain the intersection point in the above embodiment. That is, instead of the position 912 after the movement of the correction object 601, the correction object 601 approximates that it does not rotate during movement, and moves to the position 913 (indicated by a thin dotted line in the drawing) whose center has been translated. Let

  Then, the position 901 before the end point 303 is moved by the same amount as the movement vector from the position 911 to the position 913, and the line segment connecting the position 902 and the position 903 and the correction object 601 moved to the position 913 are The intersection 921 is set as a corrected position of the end point 303 (this position is based on the correction object 601).

  FIG. 9C shows how to obtain the intersection point in the present embodiment. That is, the relative position of the position 901 before the end point 303 is moved with respect to the correction object 601 at the position 911 before the movement is considered (an arrow and a thin one-dot broken line in the figure).

  Then, this vector (in the drawing, an arrow extending from the center of the correction object 601) is moved by the same amount as the movement amount and the rotation amount of the correction object 601. As a result, the relative position 952 of the end point 303 with respect to the correction object 601 before the minute time elapses is obtained (based on the position 912 of the movement destination of the correction object 601 after the minute time has elapsed). After moving the arrow and thin dashed line).

  Therefore, an intersection 953 between the line segment connecting the position 902 and the position 952 and the correction object 601 moved to the position 912 is set as a corrected position of the end point 303 (this position is based on the correction object 601 as a reference). )

  It is also possible to adopt a method equivalent to the present method in which the order of rotational movement and parallel movement is changed or the direction is reversed. In this way, any method for obtaining the same position as the intersection obtained on the surface of the correction object 601 is included in the scope of the present invention.

  This method is particularly suitable when the minute time has to be long due to the limitation of the computer capacity, or when the correction of the end point 303 is performed according to the present method as in the above embodiment. It is possible to prevent as much as possible the situation in which the user passes through the obstacle object 402.

  As described above, the movement in the virtual three-dimensional space between the cloth body and the obstacle that does not intersect the cloth body is simulated, and for example, the situation where the skirt clings to the human foot is approximately reproduced. Simulation apparatus, simulation method, and program that realizes these on a computer can be provided. For example, in the field of games, three-dimensional graphics in the above situation can be displayed at high speed. Etc. can be applied.

It is explanatory drawing which shows schematic structure of the typical information processing apparatus with which the simulation apparatus which concerns on one of embodiment of this invention is implement | achieved. It is a mimetic diagram showing the outline composition of the simulation device concerning one of the embodiments of the present invention. It is explanatory drawing which shows the mode of a line-shaped object and its end point. It is explanatory drawing which shows the relationship between the obstruction object and line segment object in virtual three-dimensional space. It is a schematic diagram which shows the flow of control of the simulation process in this embodiment. It is explanatory drawing which shows the relationship between the object for a correction | amendment, the position before correction | amendment of an end point, and the position after correction | amendment. It is explanatory drawing which shows the relationship between the object for a correction | amendment, the position before correction | amendment of an end point, and the position after correction | amendment. It is a schematic diagram which shows the flow of control of the simulation process in this embodiment. It is explanatory drawing explaining the method of calculating | requiring an intersection in the correction | amendment in embodiment of this invention.

Explanation of symbols

100 Information processing apparatus 101 CPU
102 ROM
103 RAM
104 Interface 105 Controller 106 External Memory 107 Image Processing Unit 108 DVD-ROM Drive 109 NIC
DESCRIPTION OF SYMBOLS 110 Audio | voice processing part 111 Microphone 201 Simulation apparatus 202 Storage part 203 Calculation part 204 Update part 205 Correction part 206 Output part 301 Cloth-like object model 302 Line segment object 303 End point 401 Virtual three-dimensional space 402 Obstacle object 412 Thigh 413 Knee joint 414 Tibi 415 Ankle joint 416 Foot tip 601 Correction object 602 Position before correction 603 Intersection (candidate position after correction)
604 Position advanced from intersection (candidate position after correction)
611 Center of sphere 612 Surface of polyhedron 613 Perpendicular line 614 Center axis of cylinder 615 Half line 621 Line segment 622 Half line

Claims (12)

A simulation device for simulating a state in which a plurality of line-shaped objects that expand and contract and a plurality of obstacle objects that should not intersect any of the plurality of line-shaped objects move in a virtual three-dimensional space. ,
The position information of the end points of the plurality of line segment objects and the shape, position, and posture information of the plurality of obstacle objects are stored, and each of the plurality of obstacle objects is stored in each of the plurality of end points. Is stored in association with the correction object,
Based on the position information of each of the plurality of end points stored in the storage unit, the tension of the line-shaped object connecting the end points is calculated, and the end point moves after a predetermined minute time by the calculated tension. The power position is calculated, and the shape, position, and posture that the obstacle object should take after the predetermined minute time are determined from the shape, position, and posture information of the plurality of obstacle objects stored in the storage unit. A calculation unit that calculates based on predetermined rules,
The calculated position that each of the plurality of end points should move after the minute time is stored in the storage unit as position information of the end points of the line segment object, and each of the plurality of obstacle objects The shape, position and orientation to be taken after the minute time are stored in the storage unit as the shape, position and posture information of the obstacle object, and the information stored in the storage unit is stored as information after the minute time. Update part to update,
Whether or not each of the plurality of end points is subject to correction each time the updating unit performs an update, and the end points to be corrected are included in any of the plurality of obstacle objects. If the position is included, the position of the included end point is corrected by the shape, position, and orientation information of the correction object stored in the storage unit in association with the end point. A correction unit that stores the position information of the end points in the storage unit and corrects the information stored in the storage unit;
From the position information of the end points of the plurality of line segment objects stored in the storage unit and the shape, position, and posture information of the plurality of obstacle objects, an image indicating the state of these objects is displayed in a predetermined cycle. With an output unit that generates and outputs
The predetermined period is at least twice as long as the predetermined minute time,
When the update by the update unit is an update immediately before an image is generated by the output unit, the correction unit corrects all of the plurality of end points, and the update by the update unit performs the output. When the update is not performed immediately before the image is generated by the unit, the correction is performed using a part of the plurality of end points as a correction target. The simulation apparatus according to claim 1, wherein an integer m (2 ≦ m) and an integer i (1 ≦ i ≦ m) are
The predetermined period is a length of (m + 1) times the predetermined minute time,
The plurality of end points are classified and stored in m groups from the first to the m-th in the storage unit,
When the update by the update unit is the i-th update from the update immediately before the output unit generates an image (hereinafter referred to as “0th update”), the storage unit among the plurality of end points The correction is performed with the end points classified and stored in the i-th group as correction targets. The simulation apparatus according to claim 1, wherein an integer m (2 ≦ m), an integer s, and a constant integer C,
The predetermined period is a length of (m + 1) times or more of the predetermined minute time,
The plurality of end points are classified and stored in m groups from the first to the m-th in the storage unit,
If the update by the update unit is not the update immediately before the image is generated by the output unit and is the s-th update, the storage unit among the plurality of end points ((s + C) mod m) + An object characterized in that correction is performed with the end points classified and stored in the first group as correction targets. The simulation apparatus according to claim 2 or 3, wherein
The storage unit stores, for each of the plurality of end points, the end points so as to be classified into different groups from the end points and other end points adjacent to each other via the line-shaped object. object. The simulation apparatus according to any one of claims 1 to 3,
For each of the end points to be corrected, the correction unit corrects the position of the end point according to the shape, position, and orientation information of the correction object stored in the storage unit in association with the end point. A segment connecting the position before the end point is updated by the same distance in the same direction as the movement of the correction object and the position after the end point is updated. However, the object is characterized in that the position of the end point is corrected at a position that intersects the surface of the correction object. The simulation apparatus according to any one of claims 1 to 3,
The correction unit, for each of the end points to be corrected, the position of the end point is based on the shape, position, and orientation information stored in the storage unit for the plurality of obstacle objects. Included in any of the above, a line connecting a position where the position before the end point is updated by the same distance in the same direction as the movement of the correction object by the update and a position after the end point is updated An object in which the position of the end point is corrected at a position where the minute intersects the surface of the correction object. The simulation apparatus according to any one of claims 1 to 3,
When the shape of the correction object stored in the storage unit is a cylinder,
When correcting the position of the end point associated with the correction object, the correction unit starts from any point on the central axis of the cylinder, is orthogonal to the central axis, and determines the position of the end point before the correction. An object characterized in that a position where a passing straight line intersects the surface of the cylinder is a corrected position of the end point. The simulation apparatus according to any one of claims 1 to 3,
When the shape of the correction object stored in the storage unit is a cylinder,
When correcting the position of the end point associated with the correction object, the correction unit starts from any point on the central axis of the cylinder, is orthogonal to the central axis, and determines the position of the end point before the correction. An object characterized in that a position where a passing straight line further advances by a predetermined minute distance from a position intersecting the surface of the cylinder is a corrected position of the end point. The simulation apparatus according to any one of claims 1 to 3,
When the shape of the object for correction stored in the storage unit is a polyhedron, and any one or more of the faces of the polyhedron is set as a correction surface,
When correcting the position of the end point associated with the correction object, the correction unit intersects the side surface with a perpendicular line that is closest to the end point among the surfaces set as the correction surface of the polyhedron. The position to be used is the position after correction of the end point. The simulation apparatus according to any one of claims 1 to 3,
When the shape of the object for correction stored in the storage unit is a polyhedron, and any one or more of the faces of the polyhedron is set as a correction surface,
In the case where the correction unit corrects the position of the end point associated with the correction object, a vertical line that is the closest to the end point among the surfaces set as the correction surface of the polyhedron is the correction surface. A position that is further advanced by a predetermined minute distance from a position that intersects with the end point is a corrected position of the end point. Simulating and experimenting how a plurality of line-shaped objects that expand and contract and a plurality of obstacle objects that should not intersect any of the plurality of line-shaped objects move in a virtual three-dimensional space, a storage unit, and a calculation A simulation method that is executed by a simulation apparatus including a unit, an update unit, a correction unit, and an output unit,
The storage unit stores position information of the end points of the plurality of line-segment objects and shape, position, and posture information of the plurality of obstacle objects, and each of the plurality of end points is the plurality of obstacles. Stored in association with one of the object objects as a correction object,
The calculation unit calculates the tension of the line-shaped object connecting the end points from the position information of the plurality of end points stored in the storage unit, and the end point is determined to be a predetermined minute amount by the calculated tension. The position that should be moved after time is calculated, and the shape that the obstacle object should take after the predetermined minute time from the shape, position, and orientation information of the plurality of obstacle objects stored in the storage unit A calculation process for calculating the position and orientation based on a predetermined rule;
The update unit causes the storage unit to store the calculated position that each of the plurality of end points should move after the minute time as position information of the end points of the line-shaped object, and the plurality of faults The shape, position, and posture that each object object should take after the minute time are stored in the storage unit as shape, position, and posture information of the obstacle object, and the information stored in the storage unit is stored in the minute time. Update process to update to later information,
Each time the correction unit is updated by the updating unit, a part or all of the plurality of end points are set as correction targets, and the end points to be corrected are included in any of the plurality of obstacle objects. If it is included, the position of the included end point is corrected based on the shape, position, and orientation information of the correction object stored in the storage unit in association with the end point. A correction step of storing the stored position in the storage unit as position information of the end point, and correcting the information stored in the storage unit,
The output unit shows the state of the end points of the plurality of line-shaped objects stored in the storage unit and the shape, position, and orientation information of the plurality of obstacle objects. An output process for generating and outputting images at a predetermined cycle;
The predetermined period is at least twice as long as the predetermined minute time,
In the correction step, when the update in the update step is an update immediately before an image is generated in the output step, correction is performed using all of the plurality of end points as correction targets, and the update by the update unit is performed in the output When the update is not performed immediately before the image is generated by the unit, the correction is performed by correcting a part of the plurality of end points. A program that causes a computer to simulate a situation in which a plurality of line-segment objects that expand and contract and a plurality of obstacle objects that should not intersect any of the plurality of line-segment objects move in a virtual three-dimensional space. And the program runs the computer,
The position information of the end points of the plurality of line segment objects and the shape, position, and posture information of the plurality of obstacle objects are stored, and each of the plurality of obstacle objects is stored in each of the plurality of end points. Is stored in association with the correction object,
From the position information of each of the plurality of end points stored in the storage unit, the tension of the line-shaped object connecting the end points is calculated, and the end point moves after a predetermined minute time by the calculated tension. The power position is calculated, and the shape, position, and posture that the obstacle object should take after the predetermined minute time are determined from the shape, position, and posture information of the plurality of obstacle objects stored in the storage unit. A calculation unit that calculates based on predetermined rules,
The calculated position that each of the plurality of end points should move after the minute time is stored in the storage unit as position information of the end points of the line segment object, and each of the plurality of obstacle objects The shape, position and orientation to be taken after the minute time are stored in the storage unit as the shape, position and posture information of the obstacle object, and the information stored in the storage unit is stored as information after the minute time. Update part to update,
Whether or not each of the plurality of end points is subject to correction each time the updating unit performs an update, and the end points to be corrected are included in any of the plurality of obstacle objects. If the position is included, the position of the included end point is corrected by the shape, position, and orientation information of the correction object stored in the storage unit in association with the end point. A correction unit that stores the position information of the end points in the storage unit and corrects the information stored in the storage unit;
From the position information of the end points of the plurality of line segment objects stored in the storage unit and the shape, position, and posture information of the plurality of obstacle objects, an image indicating the state of these objects is displayed in a predetermined cycle. Function as an output unit that generates and outputs in
The predetermined period is at least twice as long as the predetermined minute time,
When the update by the update unit is an update immediately before an image is generated by the output unit, the correction unit corrects all of the plurality of end points, and the update by the update unit performs the output. When the update is not performed immediately before the image is generated by the unit, the program functions to correct a part of the plurality of end points as correction targets.

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