JP2010134872A - Image processing method, image processing device, image processing program, and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for rendering a contour-like line polygon of high display quality. <P>SOLUTION: Intersection points that are apexes at which polygons intersect with a predetermined plane are acquired, and after the intersection points are collected, the intersection points are sorted by distance. Coordinate information is updated by using a middle point of one piece of coordinate information and another piece of coordinate information that is adjacent, of the sorted coordinate information. Then the coordinate of a vector in the direction of a viewpoint or a camera is added to the coordinate of the sorted intersection points. Based on the coordinate of the sorted intersection points, to which the coordinate of the vector is added, a connected line segment is rendered as 3D-CG by using information processing device. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an image processing method, an image processing apparatus, an image processing program, and a storage medium for a virtual three-dimensional space. And a storage medium.

Conventionally, a device for drawing advanced CG (computer graphics) has been mounted only on a commercial CG production device or an expensive game device in a game facility ordinarily called a “game center”.
However, advanced CG has become common due to remarkable progress in computing power of computers in recent years. Actually, graphic processors that draw three-dimensional computer graphics on objects and landscapes that are so detailed that they are mistaken for live-action images are sold at a relatively low cost.

In such a graphic processor, an image called texture is pasted on tens of thousands to millions of polyhedrons called “polygons” to express brightness and shadows, and a unit of several tens to several hundred times per second Render (draw) in real time (actual speed) to draw a three-dimensional object or landscape. Furthermore, recent advanced graphic processors are being realized that enable CG expressions that require more computing power, such as light source tracking (ray tracing) and radiosity.
Such graphic processors have been incorporated not only in expensive external graphic boards of ordinary PCs (personal computers) but also in portable terminals such as video game machines for general consumers (consumer) and mobile phones. ing.

However, in the case of conventional 3D computer graphics (virtual 3D space drawing method), an object composed of a plurality of polygons is actually projected by affine transformation or the like on a 2D liquid crystal display or the like. Is done.
For this reason, even if realistic expression is possible, it is sometimes difficult to read a three-dimensional sense such as height.

Therefore, a technique for indicating the “height” of an object composed of a plurality of polygons expressed using a drawing expression is required.
However, since the number of polygons drawn by the graphic processor has increased in recent years, the polygon “height” is calculated from each polygon constituting the object in the virtual three-dimensional space, that is, the object in the virtual space. It was difficult to ask for height and altitude.
Further, when the predetermined height positions of the polygons are simply connected by “straight lines”, there is a problem that the jaggedness of the straight lines is noticeable. That is, there is a problem in that the linearity of the line segment is uncomfortable when compared with the rendering in which brightness and shadow are smoothly expressed.

For this reason, it is conceivable to draw the vertices with a curved line instead of connecting the vertices with a straight line. As a method for drawing such a curve, a Bezier curve or a B-spline curve is used (see the prior art in Patent Document 1). However, the conventional curve drawing method has a problem that a large number of operations are required.
Therefore, referring to Patent Document 1, approximate curve calculation means for calculating the midpoint of each line segment designated by a plurality of coordinate data and generating an approximate curve by curve interpolation, and the curve calculated by the approximate curve calculation means Threshold setting means for setting a threshold relating to the error, and error determination means for comparing the threshold set by the threshold setting means and the error of the curve calculated by the approximate curve calculation means to determine the presence or absence of an error; When it is determined that there is an error by the error determining means, an approximate curve is generated by curve interpolation for each line segment divided at the midpoint of the line segment, and an error is determined by the error determining means. Memory means for storing the coordinate data when it is determined that there is no data, the outline data is stored by the coordinate data stored in the memory means. The information processing apparatus characterized by drawing a character or a figure of cement such like are disclosed (hereinafter referred to as prior art 1.).

  The information processing apparatus of Prior Art 1 takes the midpoint of a vertex and updates the vertex a plurality of times, and draws a curve when the error before and after the update is less than or equal to a predetermined value. Without performing this, curve approximation by a straight line can be performed by only addition and division that can be performed easily and quickly, so that high-speed curve interpolation processing can be performed.

Japanese Patent No. 3059739

  The conventional drawing method by the Bezier curve, the B-spline curve, and the information processing apparatus of the related art 1 updates the vertex and interpolates with the curve as it is, so that the deviation from the position information of the original vertex when the vertex is updated. Interpolation is performed with a large value, but if this is used for a drawing method in a virtual three-dimensional space, the vertex is buried behind other polygons, and the interpolated curve cannot be displayed or the drawing accuracy is reduced. There was a problem.

  This invention is made | formed in view of such a condition, and makes it a subject to eliminate the above-mentioned subject.

An image processing method according to the present invention is an image processing method in which an object formed from a plurality of polygons and a virtual viewpoint are arranged in a virtual three-dimensional space, and an image of the object viewed from the virtual viewpoint is generated. Obtaining the vertex coordinates of the polygons, obtaining the sides of the polygons based on the vertex coordinates, and obtaining the coordinate information of a plurality of points having predetermined height information for each side of the polygons; Sorting the coordinate information on the basis of the coordinate information; and taking the midpoint between one coordinate information of the sorted coordinate information and another coordinate information close to the one coordinate information, A step of updating, a step of adding direction vector coordinates based on the virtual viewpoint or the coordinate information of the virtual viewpoint to the updated coordinate information, and drawing a line from the coordinate information to which the direction vector coordinates are added Characterized in that to execute the extent the control means of the computer.
In the image processing method of the present invention, the step of obtaining the coordinate information causes the control means of the computer to execute a step of obtaining coordinate information that is an intersection with a polygon having height information at each side of each polygon. It is characterized by that.
In the image processing method of the present invention, in the step of updating the coordinate information, among the sorted coordinate information, when the coordinate information that has started sorting and the coordinate information that has been sorted are located within a predetermined distance, The step of reducing the distance between each piece of coordinate information is further caused to be executed by a computer control means.
In the image processing method of the present invention, the step of adding the direction vector coordinates causes the computer control means to execute a step of adding a direction vector to the updated coordinate information.
In the image processing method of the present invention, the step of drawing the line further causes the computer control means to execute a step of drawing a line for every three points of the coordinate information to which the direction vector coordinates are added. .
In the image processing method of the present invention, in the step of drawing the line, when the coordinate information that started drawing the line and the coordinate information that finished drawing are located within a predetermined distance, the coordinate information that started drawing the line And updating the coordinate information for which the drawing has been completed, and causing the computer control means to further execute a step of drawing a line between the updated coordinate information.
In the image processing method of the present invention, in the step of drawing the line, any one of hue, brightness, and saturation of the line is determined according to a distance from predetermined coordinate information set in the virtual three-dimensional space. Further, it is characterized in that the computer control means further executes the step of changing the above.
An image processing apparatus according to the present invention is an image processing apparatus that arranges an object formed from a plurality of polygons and a virtual viewpoint in a virtual three-dimensional space, and generates an image of the object viewed from the virtual viewpoint. The processing device obtains the vertex coordinates of each polygon, obtains the sides of each polygon based on the vertex coordinates, and obtains the coordinate information of a plurality of points having height information for each side of each polygon; Coordinates by taking a midpoint between the coordinate information sorting means based on predetermined coordinate information and one coordinate information of the sorted coordinate information and another coordinate information close to the one coordinate information. Means for updating information, means for adding direction vector coordinates based on the virtual viewpoint or the coordinate information of the virtual viewpoint to the updated coordinate information, and coordinate information obtained by adding the coordinates of the direction vector. Characterized in that it comprises a means for drawing a line.
An image processing program of the present invention is an image processing program for arranging an object formed from a plurality of polygons and a virtual viewpoint in a virtual three-dimensional space, and generating an image of the object viewed from the virtual viewpoint. A step of obtaining the vertex coordinates of each polygon, obtaining the sides of each polygon based on the vertex coordinates, obtaining coordinate information of a plurality of points having predetermined height information for each side of each polygon, and predetermined coordinate information The coordinate information is updated by taking the midpoint between the coordinate information of the sorted coordinate information and one coordinate information of the sorted coordinate information and the other coordinate information adjacent to the coordinate information. From the procedure, the procedure of adding the direction vector coordinates based on the virtual viewpoint or the coordinate information of the virtual viewpoint to the updated coordinate information, and the coordinate information to which the coordinates of the direction vector are added Characterized in that to be executed by the control means of the computer and procedures for drawing.
The recording medium of the present invention is characterized in that a program for causing a computer to execute the image processing program is configured to be readable by a computer.

  According to the present invention, since the vertex coordinates updated in the virtual viewpoint or the virtual camera direction are moved after the vertex coordinates are updated by taking the middle point between the vertex coordinates, the updated vertices are filled and the line drawing cannot be performed well. It is possible to provide a drawing method that can prevent this.

<First Embodiment>
[Control Configuration of Game Device 10]
A game apparatus 10 (information processing apparatus) according to the first embodiment of the present invention includes a PC (personal computer) such as a PC / AT compatible machine, business equipment, game equipment, general (consumer) game equipment, It is a portable terminal or the like and has an advanced CG drawing function.
Referring to FIG. 1, the game apparatus 10 includes a CPU 100 (control means), a main storage unit 110 (main storage unit), an auxiliary storage unit 120 (auxiliary storage unit), a boot ROM 130, a peripheral I / O. F140, bus arbiter 150, graphic processor 160 (drawing means), graphic memory 170, audio processor 180, audio memory 190, and communication I / F 200 are included.

  The CPU 100 includes a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Signal Processor), an ASIC (Application Specific Processor, control capability with application specific control), and the like. Means. Further, the CPU 100 can be provided with functions such as the main storage unit 110, the auxiliary storage unit 120, the graphic processor 160, and the audio processor 180.

The main storage unit 110 is a high-speed storage unit used for main storage such as a RAM (Random Access Memory).
As will be described later, the main storage unit 110 includes a collision object 450 that is mainly used for detecting a collision with another object by reducing the number of polygons of a ground object 400 described later.
The collision object 450 can also be provided on the graphic memory 170. Further, it can be dynamically generated from the ground object 400 using an adaptive mesh function of a graphic processor or the like.

The auxiliary storage unit 120 is auxiliary storage means such as an HDD (Hard Disk Drive), a flash memory, an SRAM (Static RAM), a magnetic tape device, and an optical disk device. The auxiliary storage unit 120 is provided with an OS (Operating System, not shown) for causing the game apparatus 10 to function as a computer, and each application program is operated by various APIs (Application Programming Interface). The function is accessible.
As this application program, in the game device 10 according to the first embodiment of the present invention, the collision object 450 is cut into circles at several heights and is a contour line polygon (connected line segment). A height polygon creation unit 125 for obtaining “polygon” is provided. The height polygon creating unit 125 can be provided as a unit of a class, a subroutine, or the like for use in other, for example, a golf game program. It is also possible to provide the height polygon creating unit 125 as a DLL (dynamic linking library) or a common class that is generally called from another program.

More specifically, the height polygon creation unit 125 includes a main program, an intersection acquisition unit 310 (intersection acquisition unit), an intersection sort unit 320 (intersection sort unit), a color determination unit 325 (color determination unit), and a viewpoint direction shift. The unit 330 (viewpoint direction moving unit), the curve creating unit 340 (curve creating unit), and the end point processing unit 350 (end point processing unit) include various classes and associated data.
The intersection acquisition unit 310 is a left-handed coordinate system in which the horizontal coordinate is x-coordinate, the vertical coordinate is y-coordinate, and the depth is z-coordinate (in the drawing method according to the first embodiment of the present invention, the description will be given below using the left-handed coordinate system For example, coordinate information (hereinafter referred to as an intersection) when a plurality of polygons constituting the collision object 450 and an xz plane having a predetermined height (y coordinate) intersect is obtained. For this intersection, it is possible to obtain an intersection that is not a plane.
The intersection sorting unit 320 sorts (rearranges) the intersection information acquired by the intersection acquisition unit 310 based on, for example, the distance from predetermined coordinate information (points). As this predetermined coordinate information (point), for example, when the height polygon creating unit 125 is used in a golf game, it is preferable to use the position coordinates of the position where the cup on the green in golf is set. In addition, as this position coordinate, the coordinate of the point in the virtual three-dimensional space of the position where the cup is set, or the point where the xy axis line of the position where the cup is set intersects the xz plane. Can be used. Further, as the distance from the predetermined coordinate information, it is also possible to simply use the distance from the position coordinates of the position where the virtual viewpoint is set. Furthermore, the z-axis coordinate value after the conversion from the world coordinates to the view coordinates can also be used. The intersection sorting unit 320 also performs processing for acquiring a midpoint for drawing a curve from the sorted intersection information.
The color determination unit 325 determines the color of the contour line polygon. As the color of the contour line polygon, for example, when the height polygon creating unit 125 is used in a golf game, predetermined coordinate information of golf green (a position where a cup is set or a golf ball on the green) In accordance with the height value from the position where the color is placed, a color such as a gradation of cold color to warm color can be selected and expressed.
The viewpoint direction moving unit 330 performs a process of moving each intersection by adding a vector of the line-of-sight direction. Accordingly, it is possible to prevent a curve created from the rough collision object 450 from being buried in the collision object 450 and not being drawn.
The curve creation unit 340 performs a process such as obtaining a midpoint on the vertices that have been sorted to obtain a midpoint, and creates smooth curve vertices. The process for creating the vertices of this curve will be described later. By the process of creating the vertices of the curve, it is possible to draw the curve from a small number of intersections with less error.
The end point processing unit 350 performs processing for preventing linear connection when the ends of the curve are connected. As a result, for example, when a contour-shaped curve draws a circle like a golf game cup, a smooth curve can be drawn.

  The boot ROM 130 is a non-volatile storage medium such as a ROM, a NOR flash memory, or an SRAM. When the game apparatus 10 is activated, the boot ROM 130 sets the microcode of the CPU 100, initializes each unit, and gives an instruction to activate the OS or the like from the auxiliary storage unit 120.

  The peripheral I / F 140 is a part that provides an interface such as USB, IEEE 1394, serial, parallel, infrared, and wireless for connecting to various peripheral devices (peripherals). Various peripheral devices include game pad, stick-type controller, acceleration detector, force feedback device such as vibration device, foot / hand-operated switch, position detector for detecting the position on the screen of the display monitor, CCD / CMOS camera A touch pad, a touch panel, a keyboard, a pointing device such as a mouse or a trackball, a light lighting controller, or the like can be used.

  The bus arbiter 150 is an integrated circuit that provides a bus interface for connecting each part, such as a so-called “chip set”. The bus speed of each part connected by the bus arbiter 150 may be different, and may be asymmetric in up / down. In addition, for example, it is preferable that the CPU 100, the main storage unit 110, and the bus arbiter 150 are connected by a high-speed bus such as FSB or HT, and the graphic processor 160 and the bus arbiter 150 are connected by a broadband bus. . Further, the CPU 100 may include a bus interface such as a DDR2 / 3 SDRAM or an XDR DRAM so that the main storage unit 110 can be directly read and written.

The graphic processor 160 is a graphic processor having a function of drawing advanced three-dimensional CG. The graphic processor 160 includes a geometry unit 162 that calculates polygon geometry (coordinates) and a rendering unit 164 that rasterizes / renders (renders) the polygon for which the geometry calculation has been performed. The graphic processor 160 is a RAMDAC (RAM D / A converter) for outputting an image drawn on a display monitor such as a liquid crystal display, PDP (plasma display panel), HMD (head mounted display), or projector. ) And an HDMI interface.
The geometry unit 162 is a part for obtaining coordinates of the polygon in the two-dimensional space by performing affine transformation or the like by rotating or enlarging the matrix with respect to the coordinates (world coordinates) of the polygon in the three-dimensional space. The geometry unit 162 can also include a “geometry shader” (or a vertex shader) that performs tessellation such as polygon division and spline interpolation.
The rendering unit 164 is a part that pastes image data called texture on the coordinate-calculated polygon and draws it in the graphic memory 170 with various effects. As these various effects, calculation of light spot / shadow (shading), expression of light and darkness, translucency, blur, fog, blur, HDR (high dynamic range composition), etc. are performed using a programmable shader or the like. it can. The types of polygons rendered by the rendering unit 164 include point polygons (points), line polygons (line lists), surface polygons such as triangles and quadrangles, and surface polygon aggregates. In addition, when the rendering unit 164 performs rendering using ray tracing or the like, an object defined by a region such as a circle, an ellipse, a sphere, or a metaball can be rendered.
The geometry unit 162 may be configured to be processed by the CPU 100. In this case, the coordinates of polygons created by the CPU 100 executing the program stored in the main storage unit 110 are transferred to the graphic memory 170. The rendering unit 164 draws the polygon according to the polygon coordinates.

The graphic memory 170 is a storage medium that can be read and written at high speed for the graphic processor 160 to draw. For example, a wide-band memory such as GDDR (Graphics Double Data Rate) can be connected as the graphic memory using a high level interleaving or the like. Further, a configuration in which a graphic memory is built in the graphic processor 160 as in the case of a system LSI is also possible. It is also possible to adopt a dual port configuration for displaying on a display monitor while the graphic processor 160 is drawing.
The graphic memory 170 according to the first embodiment of the present invention can include, for example, a ground object 400 and an object object 410 that are formed of a large number of polygons as polygon information for a golf game. . As the polygon information, the three-dimensional coordinates, texture, color, light source position, etc. of the polygon can be stored.
The ground object 400 is a polygon aggregate object that stores information on a large number of polygons for rendering the terrain. The ground object 400 includes a large number of polygons of tens of thousands to hundreds of thousands, or data for complementing and rendering polygons by tessellation. Realistic (realistic) drawing. The ground object also includes objects for natural expression by “fur (shading)” such as grass and grass. Since the ground object 400 includes a large number of polygons as described above, it is not easy to perform a collision / intersection calculation between the ground object 400 and an object such as a ball. For this reason, in the drawing method according to the first embodiment of the present invention, the collision object 450 in which the number of polygons of the ground object 400 is reduced is used.
The object object 410 is a polygon aggregate object that stores polygon information of an object related to a landscape such as a tree or a building. Actually, when the collision calculation of a ball or the like is performed, it is preferable to perform the collision calculation by using a polygonal aggregate including the collision object 450 and the object object 410. In addition, the object object 410 and the ground object 400 can be configured as integral data or in a separated state.

The audio processor 180 is a DSP (digital signal processor) provided with a PCM (Wave) sound source for outputting music, voice, and sound effects. The audio processor 180 can calculate physical sound sources, FM sound sources, and the like, and can also calculate various sound effects such as reverberation and reflection. The output of the audio processor 180 is D / A (digital / analog) converted, connected to a digital amplifier or the like, and is actually reproduced as music, sound, or sound effect by a speaker. The audio processor 180 also supports voice recognition of voice input from a microphone.
The audio memory 190 is a storage medium that stores digitally converted data for music, voice, and sound effects. Of course, the audio processor 180 and the audio memory 190 may be integrally configured.

  The communication I / F 200 is connected to a network such as a LAN (Local Area Network) or a WAN (Wide Area Network) (for example, wired / wireless LAN, WiMax (registered trademark), telephone line, mobile phone) Network, PHS network, power line network, cLink, HDMI, IEEE 1394, etc.) interface. Via the communication I / F 200, it is possible to connect to other game devices or server devices so as to be communicable. Thus, for example, in the case of a golf game, the server device to which a plurality of game devices are communicably connected can play together with players of other game devices that are communicably connected, and the score can be counted. It is possible to go.

[Drawing Processing According to First Embodiment of the Present Invention]
2 to 11, when the game apparatus 10 is used to perform the drawing process according to the first embodiment of the present invention, the contour line polygon of the green portion of the golf game is performed. An example of drawing will be described.
As described above, when there are many polygons to be drawn as in recent graphic processors, coordinate calculation such as collision between an object that is a collection of polygons such as the ground and a person and other objects (hereinafter referred to as collision calculation). Therefore, there is a problem that a huge amount of computing power is required.
For this purpose, the game apparatus 10 according to the first embodiment of the present invention uses a collision object 450 that is a small number of polygon objects (coarse) called a “collision object” for the collision calculation. With this collision object 450, even when a dedicated “physical calculation” hardware is not used, when a person or object such as the object object 410 contacts or collides with the ground, the calculation is performed with sufficient accuracy and at high speed. be able to.
Furthermore, in the drawing method according to the first embodiment of the present invention, contour line polygons (height polygons) are formed on the ground object 400, which is complex and data of many polygons, using this collision object. Can be drawn.
This eliminates the need for heavy (complex) calculations using a large number of polygons such as the ground object 400, and provides an effect of drawing contour line polygons in real time.
Further, by drawing a line polygon on a large number of polygons such as the smooth ground object 400, it is possible to obtain an effect that the user can easily obtain three-dimensional information of the polygon and an object that is an aggregate of the polygons.
Hereinafter, the drawing process according to the first embodiment of the present invention will be described in detail with reference to the conceptual diagram of the data configuration of FIG. 2 and the flowchart of FIG.

[Data structure of height polygon creation unit 125]
First, the data configuration used by the height polygon creation unit 125 will be described with reference to FIG.
The data used by the height polygon creation unit 125 includes, for example, a collision object D101, intersection coordinates D102 (vertex coordinates, coordinate information), contour line lower edge height D103, contour line upper edge height D104, as shown in the table of FIG. An array (array variable) or a variable such as a contour line interval D105 can be used.

The collision object D101 extracts and stores the three-dimensional coordinates of each vertex of each polygon from the list of triangles and square polygons of the collision object 450.
To explain with a specific example, the collision object D101 includes four single-precision floating-point real number data of x-axis, y-axis, and z-axis values indicating three-dimensional coordinates and w-values for matrix calculation. A vector (vec4f) type array (for example, tris []) can be used. Here, in order to make it easy to increase or decrease the number of vertices, the region object D101 is configured in a data format such as a linked list of structures, and 3 such as “.pos1”, “.pos2”, “.pos3”, etc. The coordinates of each vertex of the square and a pointer indicating the next structure of the collision object D101 “.next” may be stored as an element of the link list. In this case, tris [number of vertices]. At the end of next, a value such as NULL (NiL, empty, 0) indicating the end of the link list is stored.
In the following, [] indicates an array. As this array, a set of vectors and matrices can be used like an array of structures. In the embodiment of the present invention, the “array” includes a data format such as a link list (list).
The values used for these arrays and variables should be floating-point real data such as double-precision and double-precision, fixed-point real data, and integer data, not single-precision floating-point real numbers. Of course it is also possible.

The intersection coordinate D102 is a coordinate of an “intersection” that is a point at which a line connecting each vertex of the triangle or square polygon of the collision object D101 intersects with an xz plane parallel to the x coordinate and the z coordinate. The coordinates of the vertices of the curve created by obtaining an intermediate point from the intersection are stored.
To explain with a specific example, use an array (for example, array hline_list [] []) that stores the coordinates of the above-mentioned "intersection" and the coordinates of the vertices of a curve created by obtaining an intermediate point from the intersection. Can do.
In addition, this arrangement can be used by securing a region of the number of contour line polygons to be drawn × the number of coordinates of each curve.

The contour line lower end height D103 is a minimum value indicating the height of the xz plane.
As a specific example, the contour bottom edge height D103 can be a variable (for example, variable hline_min) indicating the minimum height for drawing contour line polygons.
Further, as the value of the contour line lower end height D103 to be substituted into this variable, for example, in the case of a golf game, the minimum value of the green portion can be used.
As will be described later, in the drawing method according to the first embodiment of the present invention, when the height polygon creating unit 125 is used for the projection shadow expression, the objects constituting the person, the object, etc. in the virtual space are displayed. The minimum height of the surrounding ground can be used.
Furthermore, it is possible to simply use a value such as the minimum value / maximum value of the y coordinate of the ground object.

The contour line upper end height D104 is the maximum value indicating the height of the xz plane.
As a specific example, the contour line upper end height D104 can use a variable (for example, variable hline_max) indicating the maximum height at which a contour line polygon is drawn.
As a value of the contour line upper end height D104 to be substituted into this variable, for example, in the case of a golf game, the maximum value of the height of the green portion can be used.

The contour line interval D105 is a value indicating the height interval (contour line interval) of the xz plane for drawing contour line polygons.
As a specific example, the contour line interval D105 can be a variable (for example, a variable hline_width) indicating an interval for drawing contour line polygons.
For example, in the case of a golf game, the value of the contour line interval D105 assigned to this variable is the number of contour line polygons drawn by subtracting the value of the contour line bottom edge height D103 from the value of the contour line top edge height D104 (contour lines). It is calculated by dividing by the number of

In addition, values related to the respective contour line polygons can be used.
Specifically, the variable h indicating the value related to each contour line polygon is an integer variable, the initial value is 0, and incremented after execution in the loop of the main program of the height polygon creation unit 125 described below. The number of contour lines is the maximum value.

In addition, the number of vertices (the initial value is 0) can be provided as a value related to the number of intersection points or curve vertices stored in the array of intersection point coordinates D102.
To explain with a specific example, the number of vertices num is provided as a variable that is the number of intersection points or curve vertices stored in the array hline_list [] [] of the intersection coordinate D102. For the number of vertices num, the number of elements of the intersection coordinates D102 at each value of the variable h (for example, the number of elements of hline_list [variable h] []) is substituted and used when necessary.

  In addition, it is possible to prepare as many link lists and arrays (for example, p [] []) for new line polygons as possible for drawing a curve as many as the number of contour lines.

In the following, referring to the flowchart of FIG. 3, the processing of the main program of the height polygon creating unit 125 will be described following each step.
It can be seen that the height polygon creation unit 125 calls each process (function) as many as the number of contour lines, as shown by the loop of FIG.
The following drawing processing can be realized by the CPU 100 executing and controlling the programs and classes of the height polygon creating unit 125 stored in the auxiliary storage unit 120 using hardware resources. .

(Step S101)
First, the height polygon creation unit 125 performs vertex acquisition processing.
In this vertex acquisition process, the height polygon creation unit 125 obtains the vertex coordinates of the triangle or the quadrilateral polygon of the collision object 450 where the contour line polygon is to be created, that is, the contour line is to be drawn.
Specifically, the height polygon creation unit 125 stores the acquired vertex coordinates in the main storage unit 110 or the auxiliary storage unit 120 as a linked list of the above-described collision object D101 array, and indicates the end of the array. The pointer is set to NULL.
In this process, the height polygon creation unit 125 obtains the number of contour line polygons to be drawn (hereinafter referred to as the number of contour lines). The number of contour lines can be set to a predetermined value, such as 50, or a suitable number can be determined from the difference between the value of the contour line lower end height D103 and the value of the contour line upper end height D104. . An optimal value can also be obtained by using the number of polygons in the viewpoint.

(Step S102)
Here, the height polygon creation unit 125 determines whether all the contour lines are processed.
Specifically, the height polygon creation unit 125 determines whether or not the processing for creating all contour line polygons is completed within the loop of the loop of FIG.
As this loop, for example, a loop structure such as a for () loop can be used. Here, the height polygon creation unit 125 sets the initial value of an integer variable h indicating the number of contour line polygons to be processed to 0, and then the height polygon creation unit 125 draws the variable h. Determine if the number of contour lines is exceeded.
(When Step S102 is Yes)
When it is determined that the variable h is equal to or exceeds the number of contour lines to be drawn, it is assumed that all the contour lines are processed, and the drawing process according to the first embodiment of the present invention is terminated.
(When Step S102 is No)
When it is determined that the variable h is less than the number of contour lines to be drawn, each process in the loop is executed. The height polygon creation unit 125 increments the variable h and makes a determination such as adding 1 to the variable h after each process in the loop.

(Step S103)
Here, the intersection acquisition unit 310 of the height polygon creation unit 125 performs intersection calculation processing.
That is, the intersection acquisition unit 310 obtains an intersection between the collision object 450 and the xz plane, and stores it in the intersection coordinate D102.
Explaining with a specific example, in this intersection calculation process, all intersections are calculated for the link list of the collision object D101, which is a list of triangles and squares obtained in step S101. In other words, in the calculation of the intersection point, a variable “trig” that indicates a triangle polygon pointer called Triangle is defined, and the address of the array (tris []) is passed to this variable tri. That is, the variable tri can indicate each polygon. On this, tri. Indicating each element of the array (tris []). Until next becomes NULL, that is, until all the polygons are processed, the intersection calculation at the height of the xz plane related to each polygon and the variable h is performed as a loop such as for () or until ().
Hereinafter, with reference to the flowchart of FIG. 4, the specific process flow of the intersection calculation process in step S103 will be described in more detail.

(Step S1031)
First, the intersection acquisition unit 310 performs polygon three-dimensional coordinate acquisition processing. In other words, each vertex of the triangular polygon for which the intersection is calculated is acquired.
Specifically, for example, the coordinates of each vertex of tri are added to p1, p2, and p3, which are vec4f type variables indicating the above-described three-dimensional coordinates, tri. pos1, tri. pos2, tri. Each of pos3 is substituted and stored.

(Step S1032)
Next, the intersection acquisition unit 310 performs contour line height acquisition processing.
In this processing, the height of the above-described xz plane, that is, “the height of the contour line” is calculated by adding the value of the contour line interval D105 × the value of the variable h to the value of the contour line lower end height D103.
To explain with a specific example, a variable indicating the height of the contour line (variable hline_point) is prepared, and the following equation (1) is calculated to obtain “the height of the contour line”.

hline_point = hline_min + hline_width × h (1)

(Step S1033)
Next, the intersection acquisition unit 310 determines whether the line segments p1 and p2 have intersections with the xz plane.
That is, in this determination, it is determined whether or not the line segment connecting the apexes p1 and p2 has an intersection with a plane parallel to the xz plane according to the height of the contour line.
More specifically, it is determined whether there is an intersection between the plane of y = hline_point in the left-handed coordinate system and the line segments p1 and p2.

(Step S1034)
If the determination in step S1033 is YES, the intersection acquisition unit 310 performs a process of adding the coordinates of the intersection to the intersection coordinates D102.
Explaining with a specific example, when there is an intersection, the intersection acquisition unit 310 stores the intersection in the intersection coordinates D102 (for example, as hline_list [variable h] [vertex number num]). In this case, the number of intersection points (in this embodiment, the value of the vertex number num) is further incremented.

(Step S1035)
If the determination in step S1033 is NO, or after the processing in step S1034, the intersection acquisition unit 310 determines whether the line segments p2 and p3 have intersections with the xz plane.
That is, in this determination, it is determined whether or not the line segment connecting the apexes p2 and p3 has an intersection with a plane parallel to the xz plane according to the height of the contour line.
More specifically, it is determined whether there is an intersection between the plane of y = hline_point in the left-handed coordinate system and the line segments p2 and p3.

(Step S1036)
If the determination in step S1035 is YES, the intersection acquisition unit 310 performs processing for adding the coordinates of the intersection to the intersection coordinates D102.
Specifically, in this process, as in step S1034, when there is an intersection, the intersection acquisition unit 310 stores it in the intersection coordinate D102 (for example, as an array hline_list [variable h] [number of vertices num]). . Then, the number of intersection points (here, the value of the vertex number num) is incremented.

(Step S1037)
When the determination in step S1035 is NO, or after the process in step S1036 is performed, the intersection acquisition unit 310 determines whether the line segments p3 and p1 have intersections with the xz plane.
That is, in this determination, it is determined whether or not the line connecting the vertices p3 and p1 has an intersection with a plane parallel to the xz plane according to the height of the contour line.
More specifically, it is determined whether there is an intersection between the plane of y = hline_point in the left-handed coordinate system and the line segments p3 and p1.

(Step S1038)
If the determination in step S1037 is YES, the intersection acquisition unit 310 performs a process of adding the coordinates of the intersection to D102.
Specifically, as in step S1034, the intersection acquisition unit 310 stores this processing in the intersection coordinate D102 (for example, as hline_list [variable h] [vertex number num]) when there is an intersection. Then, the number of intersection points (here, the value of the vertex number num) is incremented.

(Step S1039)
When the determination in step S1037 is NO, or after the processing in step S1038 is performed, the intersection acquisition unit 310 determines whether all the polygons are processed.
To explain with a specific example, it is determined whether or not the variable tri “.next” set in the array (tris []) is NULL.
If the determination in step S1039 is No, the processing in the loop is repeated for the next polygon. Specifically, the variable tri set in the array (tris []) is set as tri “.next”, and the processes in steps S1031 to S1038 described above are performed.
Conversely, if the determination in step S1039 is Yes, the intersection calculation process is terminated.
Through the intersection calculation processing described above, the intersection acquisition unit 310 can store the intersection coordinates of contour line polygons for each predetermined height related to the variable h.

Referring to FIG. 5, in the state of step S103, each intersection (vertex) of the intersection coordinate D102 is drawn together with the collision object 450 like a point polygon.
Here, each intersection group in which each intersection of the intersection coordinates D102 with the variable h being a predetermined value is depicted as an intersection 1000.
In the state of the vertex of the intersection 1000, the number of points is small, and it can be inferred that if the lines are drawn by connecting the points as they are, they are drawn as a collection of jagged lines.

(Step S104)
Here, with reference to FIG. 3 again, the intersection sorting unit 320 of the height polygon creating unit 125 performs intersection sorting / middle point complement processing.
This intersection sort / midpoint complementation processing mainly includes intersection sort processing and midpoint complementation processing, and a set of contour vertices closer to a curve can be obtained from the coordinates of the above-mentioned intersection points.
In the following, with reference to the flowchart of FIG. 6 and the conceptual diagrams of FIGS. 7A to 7E, specific processing contents of the intersection sorting / midpoint complementing processing in step 104 will be described with specific examples. In the following description, a case where there are four intersection points stored in the intersection coordinate D102 in the value of the variable h will be described with reference to FIG. 7A.

(Step S1041)
First, the intersection sorting unit 320 performs a distance acquisition initial value setting process.
With reference to FIG. 7B, a specific example will be described. First, the intersection sorting unit 320 prepares the above-described vec4f type variable X and variable start_pos indicating the coordinates of the three-dimensional space.
The intersection sorting unit 320 substitutes the coordinates for calculating the distance to each intersection into the variable X. That is, for example, in the case of a golf game, the coordinate information of the three-dimensional space of the cup set to green in the virtual space is substituted into the variable X.
It is also possible to input a coordinate farthest from a predetermined coordinate (for example, the position of the virtual viewpoint (viewpoint)) for the variable X and substitute the predetermined coordinate for the variable start_pos.

Thereafter, the intersection sorting unit 320 searches the intersection of the farthest point that is the longest (far) from the coordinate of the variable X from the intersection coordinate D102 in the value of the variable h, and substitutes the coordinate of the intersection for the variable start_pos. To do.
In the example of FIG. 7B, the intersection of the farthest points becomes the start point S, and the coordinates of the start point S are substituted into the variable start_pos.

(Step S1042)
Next, the intersection sort part 320 performs an intersection sort process.
Referring to FIG. 7C, the intersection sorting unit 320 performs sorting so that, for example, the intersection of the intersection coordinates D102 in the value of the variable h is a point close to a point far from the coordinates of the variable X.
That is, the intersection point which is the vertex farthest from a certain coordinate is set as the starting point, the closest intersection point is set as the next vertex point, and sorting is performed so that these intersection points are arranged. In this example, the intersection sorting unit 320 sorts from the start point S in the order of the vertex P1, the vertex P2, and the end point G.

(Step S1043)
Next, the intersection sorting unit 320 determines whether all intersections have been processed. That is, it is determined whether or not the sorting has been completed for all the intersections in the array of intersection coordinates D102 at the value of the variable h.
In the case of Yes, the intersection sort part 320 advances a process to step S1044.
In No, intersection sort part 320 returns processing to Step S1042, and continues sorting.

  In the example of FIG. 7C, when the sorting is finished, the intersection sorting unit 320 sorts the intersection coordinates D102 in the value of the variable h so as to be in the order of the start point S, the vertex P1, the vertex P2, and the end point G. To do.

Here, for ease of explanation, an example is shown in which intersection points are sorted using an algorithm such as selection sorting. However, all sort methods such as bubble sort and quick sort can be used for this sort.
In the drawing method according to the first embodiment of the present invention, since the collision object 450 is used, since there are few intersections, the processing time hardly poses a problem even if the selection sort or the bubble sort is used.

In the above-described intersection sort / middle point complement process, an example is shown in which sorting is performed based on the distance from a predetermined point, but the present invention is not limited to this.
As for the intersection sorting process, when the collision object D101 is acquired from the collision object 450, the intersection object D101 is sorted by the distance from a predetermined coordinate and automatically selected when the intersection coordinate D102 in the value of the variable h is selected. The coordinates may be acquired in the order of coordinates far from the predetermined coordinates or in the order of coordinates near the predetermined coordinates.
Further, instead of the intersection sorting process, the intersections of the shortest distance of the intersection coordinates D102 in the value of the variable h can be connected using a technique such as the Dijkstra method.
In addition, when there are vertices that are more than a predetermined distance by the intersection sorting process or the Dijkstra method described above, the contour line polygon is divided based on the intersection coordinates D102 in the value of the variable h. You can also. In this division, it is also possible to perform the intersection determination of the line segments connecting the intersections and to divide at the places where the intersecting lines appear. Thereby, for example, in the case of a golf game, it is possible to deal with a case where there are two or more ridges in the green set in the virtual space.
Even if the closest intersections are connected by sorting, if the number of intersections is large, an incorrect point may be selected. For this reason, it is also possible to perform (heuristic) processing using a predetermined rule of performing intersection determination of line segments connecting intersections and, for example, following intersections that are considered to be correct.
In addition, instead of determining the intersection in the first place, it is also possible to acquire line segments that intersect with the collision object 450 and connect the vertices of the line segments while maintaining the information of these line segments. is there.

(Step S1044)
When it is determined YES in step S1043, or when it is determined NO in the determination of S1045 described later, the intersection sorting unit 320 performs a midpoint complement process.
Referring to FIG. 7D, this midpoint complementing process is a process of averaging (equalizing) the sorted vertices.
That is, the middle point divided by 2 by adding the coordinates of the intersection point immediately before each intersection point to the array of intersection point coordinates D102 in the variable h is obtained and assigned (updated) to each array.

(Step S1045)
Next, the intersection sorting unit 320 determines whether all intersections have been processed.
Specifically, it is determined whether or not the intersection coordinates D102 (array hline_list [variable h] []) at each value of the variable h are updated to the midpoints.
In the case of Yes, the intersection sort unit 320 ends the intersection sort / middle point complement process. Further, the end point is added to the array of intersection coordinates D102 in the variable h.
In No, the intersection sort part 320 returns a process to step S1044, and continues a midpoint complementation process.

  FIG. 7E shows the state of each vertex after the midpoint interpolation processing is actually performed for the intersection coordinate D102 in the value of the variable h. The array of intersection coordinates D102 in the variable h is finally stored in a state such as a start point S, a vertex P1 that is a middle point, a vertex P2 that is a middle point, a middle point P3, and a new end point G.

Explaining with reference to FIG. 8, after performing the midpoint complement processing, each vertex of the intersection coordinate D102 is drawn like a point polygon as in FIG. In addition, a drawing of each intersection point of the intersection point coordinates D102 in the value of the variable h is shown as a vertex 1010 after the midpoint complementation.
In the state of the vertex 1010 after complementing the middle point in FIG. 8, the curve is closer to a smoother curve than the intersection 1000 in FIG. 5, and each midpoint is calculated and updated as a new vertex. Since the variation in the distance between the vertices is suppressed, an effect that it becomes easy to form a curve is obtained.

(Step S105)
Here, referring to FIG. 3 again, the color determination unit 325 performs color determination processing.
That is, in this color determination process, for example, in the case of a golf game, the value of the difference between the coordinates of the cup on the green that is the predetermined vertex and the height (distance in the axial direction) of the contour line polygon is used. Determine the color of the contour line polygon.
Here, a specific example will be described with reference to FIG. 9A. Here, a color to be set at each intersection of the intersection coordinates D102 in the value of the variable h is calculated. In other words, the color is calculated using the value of the contour line height (variable hline_point which is a variable indicating the height of the contour line). The height polygon creating unit 125 compares the hline_point indicating the height of the contour line with the y coordinate of the predetermined coordinate similar to the variable X described above, and calculates the intersection coordinate D102 in the value of the variable h. Calculate the color for each element (each intersection). For example, in the case of a golf game, a predetermined coordinate is set as a cup coordinate (level origin), and a difference in height from this coordinate is calculated in a predetermined unit such as “cm” from a predetermined calculation formula. When there is no difference from the coordinates of the cup due to the difference from the coordinates of the cup, the color is expressed by a light color, when it is high, the color is expressed by dark red, and when it is low, the color is expressed by dark blue.
As a color selection method, for example, an index number corresponding to the above-described contour line height value in advance in the storage unit and image information (R component, G component, B component, α (transparency) corresponding to the index number are stored. In addition to storing a color information table that associates the component) with the component), the color of the contour line polygon can be selected and expressed with reference to the color information table. Further, instead of the RGB components and the α component of the image information described above, values of hue, saturation, brightness, and luminance can be set as components.

FIG. 9B shows an example in which contour line polygons are actually drawn on the green of the golf game.
In FIG. 9 (b), the line near the cup is thin, and the contour line polygon drawn inside the green is darker and actually displayed in red. It can be easily determined that it is high.
The height of the contour line is not limited to the height of the xz plane. That is, as a distance in the axial direction, a one-dimensional distance in an arbitrary coordinate system can be used. Further, the color of the contour line polygon can be expressed more simply by using the height of the contour line and the distance from the virtual viewpoint. Also, with reference to the color of the ground object 400, the contour line polygon is drawn by performing image processing such as reversing this at a predetermined ratio depending on the height, and adding or subtracting the color component depending on the height. It is also possible to do.

(Step S106)
Returning to FIG. 3, the viewpoint direction moving unit 330 of the height polygon creating unit 125 performs the viewpoint direction moving process.
In this viewpoint direction movement process, a process of moving the coordinates of each vertex of the intersection coordinate D102 in the virtual viewpoint (viewpoint) direction is performed in order to prevent the contour line polygons from diving.
Hereinafter, a specific processing flow of the viewpoint direction movement processing in step S106 will be described with reference to the flowchart of FIG.

(Step S1061)
First, the viewpoint direction moving unit 330 performs a coordinate initial setting process.
That is, the viewpoint direction moving unit 330 sets three coordinates as coordinates of each vertex of the intersection coordinates.
Specifically, the viewpoint direction moving unit 330 uses the above-described vec4f type variables first_pos, second_pos, as coordinates 1, 2 and 3 as coordinates of each vertex of the intersection coordinate D102 in the value of the variable h. Set third_pos.
Then, a variable i for the loop counter is set, and the following processing in the loop is executed.

(Step S1062)
Here, the viewpoint direction moving unit 330 performs coordinates 1, 2, and 3 setting processing.
That is, in this process, the viewpoint direction moving unit 330 performs a process of selecting three consecutive coordinate values among the values set as the coordinate 1, the coordinate 2, and the coordinate 3.
Explaining with a specific example, the viewpoint direction moving unit 330 uses the coordinates 1, 2, and 3 as the coordinates first_pos, second_pos, and third_pos, and the intersection coordinates D102 in the values of three consecutive variables h related to the variable i. Select and assign the address (address) of the element.

(Step S1063)
Next, the viewpoint direction moving unit 330 performs coordinate 1, 2, and 3 movement processing.
In the coordinate 1, 2, and 3 movement processing, the viewpoint direction moving unit 330 first sets the three points to the virtual viewpoint or view according to the middle vertex (the variable second_pos in the above specific example) of the selected three points. The camera is moved by a predetermined value (direction vector coordinates) in the direction of the camera coordinates, such as the viewpoint of the coordinate system.
The predetermined value for moving in the direction of the viewpoint or the camera includes the maximum value of the polygon size of the collision object 450 or the ground object 400, and the maximum difference in height of the collision object 450 or the ground object 400 in the viewpoint direction. Based on the value and the like, it is possible to calculate a value for preventing the contour line polygon from being hidden.

(Step S1064)
Next, the viewpoint direction moving unit 330 determines whether all vertices have been processed.
Specifically, in the for () or until () loop, the determination is made regarding whether the variable i is equal to or greater than the number of vertices num of the intersection coordinates D102 in the variable h.
In the case of Yes, the viewpoint direction moving unit 330 ends the viewpoint direction moving process.
In No, the viewpoint direction moving part 330 increments the variable i, returns a process to step S1062, and continues the process of the loop of step S1062-step S1064.

By the viewpoint direction movement processing as described above, since the midpoint is updated in step S105, it is possible to prevent the vertex from being drawn under the ground object 400 or the collision object 450.
In addition, since it moves in the direction of the virtual viewpoint with reference to the middle vertex of the three points, there is little error in drawing, and it does not appear to float away from the ground object 400 or the collision object 450, and the true contour line The rendering result can be obtained as if it is drawn exactly on the ground. Note that the viewpoint direction movement process is not limited to being executed every three points, and the viewpoint direction movement process can be executed as long as it is a plurality of two or more vertices. Further, it is possible to perform a process for moving each vertex in the direction of the virtual viewpoint without necessarily using the middle vertex as a reference.

In addition, when this viewpoint direction movement process is not performed, in the case of a data structure in which the ground object 400 and the object object 410 are separately provided, it can be handled by changing the drawing order. For example, means such as (1) drawing the ground object 400, (2) drawing a contour line polygon, and (3) drawing the object object 410 may be considered.
However, in recent graphic processor drawing methods that draw polygons using a z-buffer or the like, it is not realistic to draw in a separate drawing order. When used for production, the display quality is significantly degraded due to errors in the z buffer.
That is, as in the drawing method according to the first embodiment of the present invention, by using the viewpoint direction movement process, drawing without considering the drawing order of a plurality of objects and not worrying about errors in the z buffer. A remarkable effect is obtained in that a contour line can be drawn on a polygon with high quality.
Such display quality is very effective especially in the field of game devices that require high image representation quality.

(Step S107)
Returning to FIG. 3, next, the curve creation unit 340 executes a curve creation process.
Here, the curve creation process will be described more specifically with reference to the conceptual diagram of FIG.

As shown in FIG. 11, it is assumed that a vertex a, a vertex b, a vertex c, and a vertex d are stored as each vertex of the intersection coordinate D102 in the value of the variable h.
First, an example will be described in which a curve creation process for making a curve with respect to three points of the vertex a, the vertex b, and the vertex c is performed.
First, the curve creation unit 340 calculates the coordinates of the vertex s, which is the midpoint between the vertex a and the vertex b.
Next, the curve creation unit 340 calculates the coordinates of the vertex t, which is the midpoint between the vertex b and the vertex c.
Next, the curve creation unit 340 calculates the coordinates of the vertex i, which is the midpoint between the vertex s and the vertex t.
Next, the curve creation unit 340 substitutes the coordinates of the vertex a, the vertex s, and the vertex i in the link list p [variable h] [] for a new line polygon for drawing a curve. I will do it.

On this basis, the curve creation unit 340 can repeat the above-described processing for the next three consecutive points, i.e., vertex i, vertex c, and vertex d.
Such processing makes it possible to calculate the curve at a higher speed than the normal Bezier curve calculation.

It should be noted that the curve creation process can be executed by another class or routine. In this case, as the variable indicating the vertices a to i, a global variable having a visible scope can be used.
For the curve drawing process, if the calculation speed is not limited, a process such as calculating a B-spline curve or a Bezier curve may be used in addition to the method of smoothing the curve using three points. Is also possible.

(Step S108)
Here, referring to FIG. 3 again, next, the end point processing unit 350 performs end point processing.
In this end point processing, for example, in the case of a golf game, the end point processing unit 350 performs processing for a case where contour lines are circular (circular) near the top of the green mountain. That is, in the above-described curve creation process, the process of making the three consecutive points from the end points approach (average and round) is performed, so that the drawing of the line polygon where the ends are connected is not smooth. Respond to the problem. More specifically, the vertex at the end for the line polygon (link list p [variable h] [0]) and the vertex at the other end (the link list p for line polygon p [variable h] [number of vertices of the curve] ]), The problem that the image appears on a straight line is processed.
Here, the vertex of the other end for the line polygon (link list p for line polygon p [variable h] [number of vertices of curve]) and the vertex for the end of line polygon (link list p [for line polygon p [ The variable h] [0]) and the vertex adjacent to the end vertex for the line polygon (link list p [variable h] [1] for the line polygon) are three consecutive points, and three points of the curve creation processing This can be dealt with by performing a process of bringing In addition, when the three points still appear to be a straight line, it is possible to perform a process of bringing the three points closer by using peripheral vertices.

As described above, the height polygon creation unit 125 can create one contour line polygon by executing steps S102 to S108. As described above, by repeating this loop, contour line polygons corresponding to the number of contour lines can be created.
After creating all the contour line polygons, the height polygon creation unit 125 uses the graphic processor 160 to draw the contour line polygons on the graphic memory 170.
Thus, the drawing process according to the first embodiment of the present invention is finished.

Referring to FIG. 12, an example is shown in which a contour line polygon, which is a curve 1020 connecting the vertices with line segments, is drawn.
Thus, it can be seen that a very smooth curve can be drawn as compared with the case where the intersection point of the xz plane in FIG. 5 is simply acquired or the case where the intersection point in FIG. 8 is simply complemented.
It is possible to draw a line polygon that is closer to the curve by repeating the midpoint interpolation process in step S104 and the “update process at the midpoint” leveled to the curve in step S107.

With the configuration described above, the following effects can be obtained.
First, the drawing method using the Bezier curve, the B-spline curve, and the prior art 1 is configured to update the vertex and interpolate with the curve as it is.
For this reason, there is a problem that accurate drawing cannot be performed because curve interpolation is performed with a large deviation from the position information of the original vertex when the vertex is updated.
As a result, when the Bezier curve, the B-spline curve, and the drawing method of the prior art 1 are used as the image processing method in the virtual three-dimensional space, the vertex is buried in another polygon after the update. . For this reason, there is a problem that the accuracy and quality of drawing are lowered.

On the other hand, in the drawing method according to the first embodiment of the present invention, after taking the midpoint between vertices and updating the vertices, predetermined vector coordinates (direction vector coordinates) in the virtual viewpoint or camera direction are obtained. Is added to the vertex and then the curve is interpolated.
As a result, it is possible to prevent the updated vertex from being buried in the ground object or the like so that it cannot be drawn or is too lifted.
In addition, since the curve is drawn after the updated vertex is directed toward the camera, it is possible to accurately draw the curve without complicated processing.
In addition, by sorting the vertices of the intersections of the polygons and then drawing like a single stroke, it is possible to create an contour line polygon with easy processing. For this reason, it is possible to reduce the calculation cost compared to the case where complicated processing such as extracting the contour line is performed by calculating inside / outside after calculating the intersection with the plane of the three-dimensional space. .
For this reason, it is possible to easily draw contour line polygons on a fine polygonal ground object 400 with a recent graphic processor having a high level of drawing ability.
In addition, in the above-described first embodiment, the collision object 450 has been described as having information that forms a surface like a triangle strip. However, in actuality, in the drawing method according to the first embodiment of the present invention, there is no information on how to form a polygon surface by vertices for an object that is a collection of polygons for which intersections are obtained, only vertices. Even if this set is used, it is possible to draw contour line polygons.

Further, in the prior art 1, since the accuracy for polygon drawing is low, when the contour line is drawn using the prior art 1 and is simply floated by adding or subtracting the y coordinate, the ground object 400 is drawn. There is a problem that the drawing quality (quality) is lowered, that is, it appears that it floats up and is buried in some places.
On the other hand, the drawing method according to the first embodiment of the present invention adds the vector of the viewpoint or camera direction to the vertex after obtaining the midpoint, moves the viewpoint in the direction of the viewpoint, and then draws the curve. In order to draw, the effect that the failure of drawing is very small is acquired.

In the above-described first embodiment, the example in which the height polygon creating unit 125 creates contour line polygons has been described. However, the present invention is not limited to this.
The drawing method according to the first embodiment of the present invention can be applied to all image processing methods in a virtual three-dimensional space in which, for example, a polygon and an intersection are obtained and a contour line is drawn like a projection shadow. is there. Drawing a projected shadow can be realized by dividing the inside of the shadow like a triangle fan and drawing darkly.
The drawing method according to the first embodiment of the present invention can also be used for polygon drawing in which a non-realistic contour line such as a toon shader is emphasized. For example, it is possible to suppress the jagged edges of the polygon from appearing on the contour line.
In addition, the drawing method according to the first embodiment of the present invention is not limited to a game, and includes various simulations, estimation of a tumor outline from a medical image, and processing of determining the shape of an object from the difference of each frame of a moving image. It can be applied and used.

  In addition, as for the drawing by the drawing method of the first embodiment of the present invention, the drawing of contour line polygons has been described. However, the polygon to be drawn is not limited to a line polygon, and may be a triangle strip or a polygonal object having a columnar thickness.

<Second Embodiment>
Next, a drawing process using the game apparatus 10 according to the second embodiment of the present invention will be described.
In the drawing processing according to the second embodiment of the present invention, by further adding processing related to the start point and end point, for example, in the case of a golf game, when the contour line is circular near the cup, it is smoother. A contour line polygon can be obtained.

[Control Configuration of Game Device 10 in Second Embodiment of the Present Invention]
In the drawing processing according to the second embodiment of the present invention, the height polygon creation unit 125 is configured to have the intersection sorting unit 320 of the height polygon creation unit 125 of the game apparatus 10 according to the first embodiment of the present invention, Further processing can be performed on the viewpoint direction moving unit 330 and the end point processing unit 350.
The intersection sorting unit 320 performs the start point / end point movement process in step S205 of FIG. 13 and makes the contour line polygons smooth by bringing the sorted start point and end point closer to each other.
The viewpoint direction moving unit 330 performs the start point direction camera moving process in step S207 of FIG. The viewpoint direction moving unit 330 can move contour line-shaped line polygons in the viewpoint direction according to the smoothness of the curve by the start point direction camera movement process.
The end point processing unit 350 performs a start point / end point curving process in step S209 described later. By this start point / end point curving process, especially when the contour line polygon is circular, the contour line polygon connecting the start point and the end point can be drawn more smoothly.

Further, as the data configuration of the height polygon creation unit 125, the same data configuration as that of the first embodiment of the present invention can be used.
Hereinafter, the flow of the drawing process of the height polygon creating unit 125 according to the second embodiment of the present invention will be described in detail with reference to the flowchart of FIG.

[Drawing Processing According to Second Embodiment of the Present Invention]
Referring to FIG. 13, the game device 10 executes the processes of steps S <b> 201 to S <b> 209 that are drawing processes according to the second embodiment of the present invention.
Here, referring again to FIG. 3, step S201 is step S101, step S202 is step S102, step S203 is step S103, step S204 is step S104, step S206 is step S105, and step S208 is step S107. The same processing can be performed.
In the drawing processing according to the second embodiment of the present invention, smooth contour line polygons are drawn by performing the processing of step S205, step S207, and step S209.
Below, each process of step S205, step S207, and step S209 is demonstrated in detail.

(Step S205)
In step S205, the intersection sorting unit 320 performs start point / end point movement processing.
Referring to FIGS. 14A to 14B, the intersection sorting unit 320 sets the start point S, the vertices P1, P2, P3, and the end point G in the same manner as the state after the intersection sort / middle point complement process in FIG. 7E described above. In such a state, a start / end point movement process is performed as a final process.
The intersection sorting unit 320 first determines whether the start point S and the end point G are close. Whether the distance is close or not is determined using a condition where the distance between the start point S and the end point G is equal to or less than a predetermined distance or a value that is equal to or less than a value such as several times the average distance between vertices. .
If the start point S and the end point G are not close, the intersection sorting unit 320 advances the process to the next step S206.
When the start point S and the end point G are close to each other, the intersection sort unit 320 performs an actual start point / end point movement process described below.

Referring to FIG. 14A, in the actual start / end point movement process:
The intersection sorting unit 320 first calculates the midpoint T of the start point S and the end point G.
Next, the intersection sorting unit 320 calculates a midpoint S ′ between the start point S and the midpoint T.
Next, the intersection sorting unit 320 calculates a midpoint G ′ between the end point G and the midpoint T.
On this, referring to FIG. 14B,
The intersection sorting unit 320 moves the coordinates of the starting point S to the coordinates of the middle point S ′.
In addition, the intersection sorting unit 320 moves the coordinates of the end point G to the coordinates of the middle point G ′.

In this way, by moving the start point S and the end point G and making the start point and end point of the intersection after sorting closer, it is possible to draw more smoothly when the contour line polygon is circular.
In addition, since the coordinates of the start point S and the end point G are also moved, other contour line polygon parts can be drawn smoothly.

(Step S207)
In step S207, the viewpoint direction movement unit 330 performs viewpoint direction camera movement processing.
In this viewpoint direction camera movement processing, in addition to the processing similar to the viewpoint direction movement processing in step S106 in the first embodiment described above, a movement amount in the camera direction is set, and contour lines in the viewpoint direction are formed. Move the line polygon.
As the movement amount in the camera direction, the viewpoint direction moving unit 330 can set the movement amount in consideration of the number of times of updating at the above-described midpoint.
Hereinafter, this viewpoint direction camera movement processing will be described in more detail.

The viewpoint direction moving unit 330 will first describe an example in which the vertex A is moved to the camera C. The camera C has coordinates like the above-described viewpoint (virtual viewpoint). Hereinafter, a specific example will be described.
For example, the coordinates of the vertex A are substituted into the above-described vec4f type variable Apos. Further, the coordinates of the camera C are substituted into the above-described vec4f type variable Cpos, for example.
Then, the vector CA from the camera C to the vertex A is similarly used as the above-mentioned vec4f type variable CAvec, and the value of this CAvec is obtained by the following equation (2).

CAvec = Cpos−Apos (2)

The unit vector of the vector CA is the above-mentioned vec4f type variable CAvec_E, and the value of this CAvec_E is obtained by the following equation (3).

CAvec_E = CAvec ÷ | CAvec | (3)

Here, the viewpoint direction moving unit 330 calculates the amount of movement in the camera direction, and substitutes it into, for example, the above-described vec4f type variable (for example, variable transfer).
As the value of the amount of movement in the camera direction (direction vector coordinates), the vector size is approximately 0 as a value finely adjusted so that contour line polygons do not float and are not buried in other polygons. A predetermined value such as .25 can be set.
Further, the viewpoint direction moving unit 330 increases the value of the amount of movement in the camera direction in proportion to the number of times of updating at the midpoint and the number of times of making a curve at three points. For example, the value of the movement amount can be increased at a ratio of approximately 1.5 times.
It is also possible to calculate using the difference in smoothness between the polygons of the collision object 450 and the ground object 400, specifically the ratio of the number of polygons.

Next, the viewpoint direction moving unit 330 obtains the value of A ′ using the following equation (4), where A ′ is the coordinate value after the vertex A is moved.

A ′ = Apos + (Cavec_E × transfer) (4)

Then, the viewpoint direction moving unit 330 substitutes the value of A ′ for the variable Apos.
This process is repeated for each vertex, and the viewpoint direction movement unit 330 ends the viewpoint direction camera movement process.

By this viewpoint direction camera movement processing, even if the collision object 450 is rougher, the contour line polygon can be surely drawn without being buried in the ground object 400 or the like, or appearing in the sky. Further, even if an error between the ground object 400 and the contour line polygon is generated by performing the update process at the midpoint multiple times, the contour line polygon is drawn without appearing to be buried or popping out of the ground object 400. Is possible.
That is, it is possible to move the contour line polygon in the viewpoint direction according to the smoothness of the line.

(Step S209)
In step S209, the end point processing unit 350 performs a start point / end point curving process.
With respect to the start point / end point curving process, when the start point and the end point are close and the start point and the end point are connected, the contour line polygon is drawn more smoothly.
Hereinafter, with reference to the flowchart of FIG. 15 and FIGS. 16A to 16C, the start point / end point curving process in step S209 will be described in more detail.

(Step S2091)
First, the end point processing unit 350 determines whether the start point and the end point are close. This determination is performed in the same manner as the determination in step S205. That is, it is determined whether or not the contour line polygon is circular, and the process proceeds to a different process depending on the result.
That is, when the above determination is Yes, since the contour line polygon is annular, the end point processing unit 350 advances the process to step S2092. Conversely, when the above determination is No, the end point processing unit 350 advances the process to step S2096 because it is not annular.

(Step S2092)
When the contour line polygon is annular, the end point processing unit 350 first performs a start point re-moving process.
With reference to FIG. 16A, the calculation of the start point re-movement process will be described in the case where there are the start point S, the vertex P1, the vertex P2, the vertex P3, and the end point G as in the above example.
The end point processing unit 350 first obtains a midpoint between the end point G and the start point S using the end point G, the start point S, and the vertex P1, obtains a midpoint between the start point S and the vertex P1, and determines the midpoint between the two midpoints. Find the midpoint S '.
Then, the end point processing unit 350 moves the coordinates of the starting point S to the coordinates of the middle point S ′.

(Step S2093)
Next, the curve creation unit 340 performs a curve creation process in the same manner as step S107 in FIG. 3 according to the first embodiment described above.
Referring to FIG. 16B, actually, the curve creation unit 340 performs a curve creation process from the moved start point S to the vertex just before the end point G. That is, the middle point T and the end point G in FIG. 16B are not connected by a line segment.

(Step S2094)
Next, the end point processing unit 350 performs a curve end point / start point curving process.
Referring to FIG. 16C, the end point processing unit 350 creates a curve using the three vertices of the midpoint T, the end point G, and the start point S.

(Step S2095)
Next, the end point processing unit 350 performs a curve end point / start point combining process.
Here, the end point processing unit 350 connects the last vertex created in step S2094 described above and the start point S. Thereby, contour line polygons connected in a smooth annular shape can be created.
The start point / end point curving process is thus completed.

(Step S2096)
When the start point S and the end point G are not close, that is, when the contour line polygon is not circular, the curve creation unit 340 performs a curve creation process as in step S107.
Referring to FIG. 17, unlike step S2093 described above, the curve creation unit 340 performs a normal curve creation process in a state where the start point S is not moved.

(Step S2097)
Next, the end point processing unit 350 performs a curve end point / end point combining process.
That is, referring to FIG. 17, the last vertex created in step S2096 described above and the end point G are connected.
As a result, it is possible to create linear contour line polygons in which the rings are not connected.
The start point / end point curving process is thus completed.

FIG. 18 shows contour line polygons drawn by the drawing processing according to the second embodiment of the present invention.
It can be seen that the contour line polygons that are circular are also drawn smoothly so as to be quite close to a circle.
As described above, the drawing process according to the second embodiment of the present invention, as described above, for example, in the case of a golf game, even if the contour line polygons are annular on the cup side or the like, the failure occurs. Less can be displayed.

Even in the rendering process according to the second embodiment of the present invention, when the polygon of the collision object 450 is rough, it is possible to render a smoother contour by repeating the update at the midpoint. That is, it is possible to draw a smooth contour line polygon by repeating the midpoint interpolation process in step S204 and the start / end curve processing in step S209.
Further, the execution order of the midpoint complementing process in step S204 and the start / end point moving process in step S205 can be changed.

  It should be noted that the configuration and operation of the above-described embodiment are examples, and it is needless to say that the configuration and operation can be appropriately changed and executed without departing from the gist of the present invention.

It is a block diagram which shows the control structure of the game device 10 which concerns on the 1st Embodiment of this invention. It is a conceptual diagram which shows the data structure which concerns on the 1st Embodiment of this invention. It is a flowchart which shows each process of the drawing method which concerns on the 1st Embodiment of this invention. It is a flowchart which shows each process of the intersection calculation process which concerns on the 1st Embodiment of this invention. It is an example of the screen which drawn the intersection which concerns on the 1st Embodiment of this invention as a point polygon. It is a flowchart which shows each process of the intersection sort / middle point complement process which concerns on the 1st Embodiment of this invention. It is an example of the vertex of the intersection coordinate D102 in the value of the variable h which concerns on the 1st Embodiment of this invention. It is a conceptual diagram which shows the distance from the predetermined coordinate to the vertex which concerns on the 1st Embodiment of this invention. It is a conceptual diagram which shows the sort of each vertex by the distance from the predetermined coordinate to the vertex which concerns on the 1st Embodiment of this invention. It is a conceptual diagram of the midpoint complementation process which concerns on the 1st Embodiment of this invention. It is a conceptual diagram which shows the mode of each vertex after performing the midpoint complementation process which concerns on the 1st Embodiment of this invention. It is the example of a screen which drawn the vertex after the midpoint complementation processing concerning the 1st embodiment of the present invention as a point polygon. It is a conceptual diagram which shows the calculation method of the color of the contour line polygon which concerns on the 1st Embodiment of this invention. It is a flowchart which shows each process of the viewpoint direction movement process which concerns on the 1st Embodiment of this invention. It is a conceptual diagram explaining the curve creation process which concerns on the 1st Embodiment of this invention. It is the example of a screen which drawn the contour line polygon according to the 1st embodiment of the present invention. It is a flowchart which shows each process of the drawing method which concerns on the 2nd Embodiment of this invention. It is a conceptual diagram explaining the starting point / ending point movement process which concerns on the 2nd Embodiment of this invention. It is a conceptual diagram which shows the mode of each vertex after performing the starting point / ending point movement process which concerns on the 2nd Embodiment of this invention. It is a flowchart which shows each process of the starting point / end point curving process based on the 2nd Embodiment of this invention. It is a conceptual diagram explaining the starting point re-moving process of the starting point / end point curving process which concerns on the 2nd Embodiment of this invention. It is a conceptual diagram explaining the curve creation process after the starting point re-moving process which concerns on the 2nd Embodiment of this invention. It is a conceptual diagram explaining the curve end point / starting point curving process according to the second embodiment of the present invention. It is a conceptual diagram of a process when the start point S and the end point G of the start point / end point curving process according to the second embodiment of the present invention are not close. It is the example of a screen which drawn the contour line-shaped line polygon of the contour line shape concerning the 2nd Embodiment of this invention.

Explanation of symbols

10 game machine 100 CPU
110 Main storage unit 120 Auxiliary storage unit 125 Height polygon creation unit 130 Boot ROM
140 Peripheral I / F
150 Bus Arbiter 160 Graphic Processor 162 Geometry Unit 164 Rendering Unit 170 Graphic Memory 180 Audio Processor 190 Audio Memory 200 Communication I / F
310 intersection acquisition unit 320 intersection sorting unit 325 color determination unit 330 viewpoint direction movement unit 340 curve creation unit 350 end point processing unit 400 ground object 410 object object 450 collision object 1000 intersection 1010 vertex 1020 curve after midpoint interpolation

Claims (10)

An image processing method for arranging an object formed from a plurality of polygons and a virtual viewpoint in a virtual three-dimensional space and generating an image of the object viewed from the virtual viewpoint,
Obtaining vertex coordinates of each polygon, obtaining sides of each polygon based on the vertex coordinates, obtaining coordinate information of a plurality of points having predetermined height information for each side of each polygon;
Sorting the coordinate information on the basis of predetermined coordinate information;
Updating the coordinate information by taking the midpoint between the coordinate information of one of the sorted coordinate information and the other coordinate information close to the coordinate information of the one;
Adding the direction vector coordinates based on the virtual viewpoint or the coordinate information of the virtual viewpoint to the updated coordinate information;
And a step of drawing a line from the coordinate information to which the direction vector coordinates are added. The step of obtaining the coordinate information includes:
The image processing method according to claim 1, further comprising: causing a computer control unit to execute a step of obtaining coordinate information that is an intersection with a polygon having height information on each side of each polygon. The step of updating the coordinate information includes:
Among the sorted coordinate information, when the coordinate information that has started sorting and the coordinate information that has been sorted are located within a predetermined distance, a step of reducing the distance between the coordinate information is further provided to the computer control means. The image processing method according to claim 1, wherein the image processing method is executed. The step of adding the direction vector coordinates includes:
4. The image processing method according to claim 1, further comprising: causing a control unit of a computer to execute a step of adding a direction vector to the updated coordinate information. 5. The step of drawing the line includes
5. The image processing method according to claim 1, further comprising: causing a control unit of a computer to execute a step of drawing a line at every three points of the coordinate information to which the direction vector coordinates are added. The step of drawing the line includes
When the coordinate information that started drawing the line and the coordinate information that finished drawing are located within a predetermined distance,
The coordinate information at which drawing of the line is started and the coordinate information at which the drawing is finished are updated, and a step of drawing a straight line between the updated pieces of coordinate information is further executed by a control means of a computer. Item 6. The image processing method according to any one of Items 1 to 5. The step of drawing the line includes
The step of changing any one of hue, brightness, and saturation of the line according to the distance from the predetermined coordinate information set in the virtual three-dimensional space is further caused to be executed by a computer control means. An image processing method according to any one of claims 1 to 6. An image processing apparatus that arranges an object formed from a plurality of polygons and a virtual viewpoint in a virtual three-dimensional space, and generates an image of the object viewed from the virtual viewpoint,
The image processing apparatus includes:
Means for obtaining vertex coordinates of each polygon, obtaining sides of each polygon based on the vertex coordinates, and obtaining coordinate information of a plurality of points having height information for each side of each polygon;
Means for sorting the coordinate information based on predetermined coordinate information;
Means for updating the coordinate information by taking the midpoint of one coordinate information of the sorted coordinate information and the other coordinate information close to the one coordinate information;
Means for adding direction vector coordinates based on the virtual viewpoint or the coordinate information of the virtual viewpoint to the updated coordinate information;
Means for drawing a line from coordinate information to which direction vector coordinates are added;
An image processing apparatus comprising: An image processing program for arranging an object formed from a plurality of polygons and a virtual viewpoint in a virtual three-dimensional space, and generating an image of the object viewed from the virtual viewpoint,
Obtaining the vertex coordinates of each polygon, obtaining the sides of each polygon based on the vertex coordinates, and obtaining the coordinate information of a plurality of points having predetermined height information for each side of each polygon;
A procedure for sorting the coordinate information based on predetermined coordinate information;
A procedure for updating the coordinate information by taking the midpoint of one coordinate information and the other coordinate information close to the one coordinate information among the sorted coordinate information;
A procedure for adding direction vector coordinates based on the virtual viewpoint or the coordinate information of the virtual viewpoint to the updated coordinate information;
An image processing program for causing a computer control means to execute a procedure for drawing a line from coordinate information to which a direction vector coordinate is added.   A recording medium configured to allow a computer-readable program for causing a computer to execute the image processing program according to claim 9.

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