JP2013050895A - Game device, game device control method, and program - Google Patents

Abstract

PROBLEM TO BE SOLVED: To draw the outline of an object disposed in a virtual space showing a game world.SOLUTION: In a game device 201, a generating unit 202 generates a first image indicating how plural objects disposed in a virtual space showing a game world appear from a viewpoint set in the virtual space in a line-of-sight direction set in the virtual space, and a second image each having a depth value indicating a depth to the viewpoint at a position drawn at each pixel position in the first image in the plural objects, as a pixel value at the pixel position. An extracting unit 203 obtains a third image by applying an outline extraction filter to the second image. A drawing unit 204 obtains a fourth image by drawing an outline indicated by the third image with the first image used as a background.

Description

  The present invention relates to a game device suitable for drawing an outline of an object arranged in a virtual space representing a game world, a control method for the game device, and a program for realizing these on a computer.

  Traditionally, a game world in which objects such as various characters and objects appear is expressed by combining polygons arranged in the virtual space and surfaces whose shapes are determined by the positions and weights of the control points. There has been proposed a technique for generating an image representing the appearance.

  In these techniques, a projection plane is set in the virtual space based on the viewpoint and the line-of-sight direction arranged in the virtual space.

  And, the perspective projection technology that projects the part to the intersection where the line connecting each point of the polygon or surface and the viewpoint intersects the projection plane, or the polygon or surface from the part of the polygon or the surface to approach the viewpoint parallel to the line of sight An image representing the state in the virtual space is generated by using a parallel projection technique in which the half-line extended to the point where the half line intersects the projection plane is projected.

  Here, if only perspective projection or parallel projection is used, the outline of the object is not drawn as a line drawing in the image representing the state in the virtual space.

  Therefore, a technique has been proposed for obtaining the contour of an object even when the position of the viewpoint or the line-of-sight direction changes.

  Here, Patent Document 1 discloses a technique for dynamically determining a threshold value when an image contour is extracted by an edge extraction filter and binarized. The present technology is based on the premise that the two regions separated by the contour are different colors.

  In Patent Document 2, a stereo model representing an object and a back model obtained by enlarging the stereo model and inverting the normal vector of the polygon are prepared, and the outline is drawn by drawing only the polygon visible from the viewpoint direction. A technique for drawing is disclosed. This technique is suitable for drawing an outline around an object.

  According to these techniques, it is possible to draw an outline that separates the object and the background in an image representing a state in the virtual space.

JP-A-5-165963 JP 2005-25785 A

  However, there is a strong demand for a technique capable of drawing an outline more easily than the above prior art.

  Furthermore, there is a desire to be able to draw an outline even when the foreground and background colors are similar. For example, when a white character is the foreground and the white virtual world is the background, or when the skin color jaw of the character is the foreground and the skin color neck is the background.

  The present invention solves the above-described problems. A game device suitable for drawing an outline of an object placed in a virtual space representing a game world, a control method for the game device, and these are stored in a computer. The purpose is to provide a program to be realized.

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

A game device according to a first aspect of the present invention includes:
A first image representing a state in which a plurality of objects arranged in a virtual space representing the game world are viewed from a viewpoint set in the virtual space in a line-of-sight direction set in the virtual space; and the plurality of objects A generation unit that generates a second image having a depth value representing a depth with respect to the viewpoint at a position drawn at each pixel position in the first image as a pixel value at each pixel position,
An extraction unit that obtains a third image by applying a contour extraction filter to the second image;
The image processing apparatus includes a drawing unit that obtains a fourth image by drawing an outline represented by the third image with the first image as a background.

In the game device of the present invention,
The generator is
The maximum value that the pixel value of the second image can take is an initial value of the pixel value at each pixel position in the second image,
For each of the plurality of objects,
(A) Find the area where the object is projected,
(B) For each pixel position in the obtained area, if the pixel value in the second image at the pixel position is smaller than the depth value for the position projected on the pixel position of the object, the position is The pixel value projected to the pixel position is obtained, the pixel value at the pixel position in the first image is updated to the obtained pixel value, and the pixel value at the pixel position in the second image is changed to the object value. By repeating the process of updating to the depth value, the first image and the second image can be generated.

In the game device of the present invention,
The depth value for each pixel position is the pixel value of the second image, which is the inner product of the vector from the viewpoint to the portion of the object projected onto the pixel position and the unit vector in the line-of-sight direction. It can be configured to be obtained by applying a monotonically increasing function whose range is an integer of a possible range.

In the game device of the present invention,
The contour extraction filter is:
The initial value of the pixel value at each pixel position in the third image is set to 0,
If each pixel position in the second image is scanned from left to right and adjacent pixel positions are scanned, and the pixel value at the left pixel position is greater than the pixel value at the right pixel position, the pixel value at the left pixel position And the pixel value of the left pixel position in the third image is updated with the difference between the pixel value of the right pixel position and the pixel value of the right pixel position,
If each pixel position in the second image is scanned from right to left and adjacent pixel positions are scanned, and the pixel value at the right pixel position is greater than the pixel value at the left pixel position, the pixel value at the right pixel position The pixel value at the right pixel position in the third image can be updated by the difference between the pixel value at the left pixel position and the pixel value at the left pixel position.

In the game device of the present invention,
The contour extraction filter further includes:
If each pixel position in the second image is scanned from top to bottom and adjacent pixel positions are scanned, and the pixel value at the upper pixel position is greater than the pixel value at the lower pixel position, the pixel value at the upper pixel position And the pixel value at the upper pixel position in the third image is updated with the difference between the pixel value at the lower pixel position and the pixel value at the lower pixel position,
If each pixel position in the second image is scanned from the bottom to the top and adjacent pixel positions are scanned, and the pixel value at the lower pixel position is larger than the pixel value at the upper pixel position, the pixel value at the lower pixel position The pixel value at the lower pixel position in the third image can be updated by the difference between the pixel value at the upper pixel position and the pixel value at the upper pixel position.

In the game device of the present invention,
The contour extraction filter is obtained by applying a monotonically increasing function whose range is an integer of a range that can be taken by the pixel value of the third image, instead of the difference between the pixel values of the adjacent pixel positions. The pixel value in the third image can be updated with the value.

In the game device of the present invention,
The drawing unit, for each pixel position of the fourth image,
(A) If the pixel value in the third image at the pixel position is 0, the pixel value in the first image at the pixel position is set as the pixel value at the pixel position in the fourth image;
(B) If the pixel value in the third image at the pixel position is not 0, the pixel has a predetermined hue and saturation and represents a color having the pixel value in the third image at the pixel position as darkness The value can be configured to be a pixel value of the pixel position in the fourth image.

In the game device of the present invention,
For each pixel position of the fourth image, the drawing unit displays the color represented by the pixel value in the first image at the pixel position, and the intensity represented by the pixel value in the third image at the pixel position. The pixel value representing the darkened color can be configured to be the pixel value at the pixel position in the fourth image.

The control method according to the second aspect of the present invention is executed by a game device having a generation unit, an extraction unit, and a drawing unit,
A first image representing a state in which the generation unit viewed a plurality of objects arranged in a virtual space representing a game world from a viewpoint set in the virtual space in a line-of-sight direction set in the virtual space; A generation step of generating a second image having a depth value representing a depth with respect to the viewpoint at a position drawn at each pixel position in the first image among the plurality of objects as a pixel value at each pixel position;
An extraction step in which the extraction unit obtains a third image by applying a contour extraction filter to the second image;
The drawing unit includes a drawing step of drawing a contour represented by the third image with the first image as a background to obtain a fourth image.

A program according to a third aspect of the present invention provides a computer,
A first image representing a state in which a plurality of objects arranged in a virtual space representing the game world are viewed from a viewpoint set in the virtual space in a line-of-sight direction set in the virtual space; and the plurality of objects A generation unit that generates a second image having a depth value representing a depth with respect to the viewpoint at a position drawn at each pixel position in the first image as a pixel value at each pixel position,
An extraction unit that obtains a third image by applying a contour extraction filter to the second image;
The first image is used as a background, and the contour represented by the third image is drawn to function as a drawing unit that obtains the fourth image.

  The program of the present invention can be recorded on a computer-readable information storage medium such as a compact disk, flexible disk, hard disk, magneto-optical disk, digital video disk, magnetic tape, and semiconductor memory.

  The above program can be distributed and sold via a computer communication network independently of the computer on which the program is executed. The information storage medium can be distributed and sold independently from the computer.

  According to the present invention, it is possible to provide a game device suitable for drawing an outline of an object placed in a virtual space representing the game world, a control method for the game device, and a program for realizing these on a computer. it can.

It is a schematic diagram which shows schematic structure of a typical information processing apparatus. It is explanatory drawing which shows schematic structure of the game device which concerns on this embodiment. It is explanatory drawing which shows the example of the object arrange | positioned in virtual space. It is explanatory drawing which shows the example of a 1st image. It is explanatory drawing which shows the prior art example which applied the outline extraction filter with respect to the 1st image. It is explanatory drawing which shows the mode of a 2nd image. It is explanatory drawing showing the mode of the 3rd image obtained by applying an outline extraction filter to a 2nd image. It is explanatory drawing which shows the mode of the 4th image obtained by overwriting and drawing the outline represented by the 3rd image on the 1st image. 3 is a flowchart illustrating a flow of control of processing according to the first embodiment. 12 is a flowchart illustrating a flow of control of generation processing of a first image and a second image according to the second embodiment. It is explanatory drawing which shows the 3rd image which extracted the outline from right and left by threshold value comparison. It is explanatory drawing which shows the 3rd image which extracted the outline from the upper and lower sides by threshold value comparison. It is explanatory drawing which shows the 3rd image which extracted the outline from the upper and lower sides, and right and left by threshold value comparison. It is explanatory drawing which shows the 4th image obtained using the outline extracted from the upper and lower sides, and right and left by threshold value comparison. It is explanatory drawing which shows the mode of the outline extracted considering the darkness from upper and lower, right and left. It is explanatory drawing showing the mode of the 4th image produced | generated using the dark opaque outline.

  Embodiments of the present invention will be described below. In the following, for ease of understanding, an embodiment in which the present invention is realized using a game information processing device will be described. However, the embodiment described below is for explanation, and the present invention It does not limit the range. Therefore, those skilled in the art can employ embodiments in which each or all of these elements are replaced with equivalent ones, and these embodiments are also included in the scope of the present invention.

(Information processing device)
FIG. 1 is a schematic diagram illustrating a schematic configuration of a typical information processing apparatus that can function as the game apparatus of the present embodiment by executing a program. Hereinafter, a description will be given with reference to FIG.

  An information processing apparatus 100 shown in the figure corresponds to a so-called consumer game machine, and includes a central processing unit (CPU) 101, a read only memory (ROM) 102, a random access memory (RAM) 103, an interface 104, a controller 105, It has an external memory 106, an image processing unit 107, a DVD-ROM (Digital Versatile Disc ROM) drive 108, a NIC (Network Interface Card) 109, an audio processing unit 110, a microphone 111, a hard disk (HD) 121, and a camera 131. . Various input / output devices can be omitted as appropriate.

  When functioning the information processing apparatus 100 as a typical consumer game machine, a user first mounts a DVD-ROM storing a game program and data on the DVD-ROM drive 108. Then, when the user turns on the power, the game program is executed, and the user can play the game.

  However, in this embodiment, typically, an application is installed in the HD 121 from a DVD-ROM. The DVD-ROM is mounted on the DVD-ROM drive 108. Then, by executing the program stored in the HD 121, various applications including a game are executed.

  Note that in a portable game device, the HD 121 can be omitted in order to be portable. In this case, the DVD-ROM drive 108 is not used. The user then installs an EEPROM (Electrically Erasable Programmable ROM) cassette in the ROM cassette slot. An application program is written in the EEPROM cassette. Then, the program is executed. In addition, an application program can be installed in the external memory 106.

  The CPU 101 controls the overall operation of the information processing apparatus 100 and is connected to each component to exchange control signals and data. The CPU 101 includes a storage area called a register (not shown) that can be accessed at high speed. The CPU 101 can perform various operations on the registers using an ALU (Arithmetic Logic Unit) (not shown). The operations to be performed include arithmetic operations such as addition, subtraction, multiplication, and division, logical operations such as logical sum, logical product, and logical negation, bit operations such as bit sum, bit product, bit inversion, bit shift, and bit rotation. Furthermore, the CPU 101 may be configured to perform high-speed saturation calculations such as addition / subtraction / multiplication / division for multimedia processing, vector calculations such as trigonometric functions, and the like. Further, the CPU 101 may realize such a high-speed calculation by including a coprocessor.

  The ROM 102 stores an IPL (Initial Program Loader) that is executed immediately after the power is turned on. By executing the IPL, the program recorded on the DVD-ROM is read out to the RAM 103. Next, execution of the program by the CPU 101 is started. The ROM 102 stores an operating system program and various data. The operating system is required to control the operation of the information processing apparatus 100 as a whole.

  The RAM 103 temporarily stores data and programs. The RAM 103 holds programs and data read from the HD 121, DVD-ROM, etc., and other data necessary for the progress of the communication battle game and chat communication. Further, the CPU 101 provides a variable area in the RAM 103. The CPU 101 may operate by directly operating the ALU on the value stored in the variable. Further, the CPU 101 may store the value stored in the RAM 103 in a register, perform an operation on the register, and write back the operation result in the memory.

  The controller 105 is connected via the interface 104. The controller 105 receives an operation input performed by the user when the game is executed.

  The controller 105 does not necessarily have to be externally attached to the information processing apparatus 100, and may be formed integrally. The controller 105 of the portable image processing apparatus includes various buttons and switches. The controller 105 handles a pressing operation on the button or switch as an operation input. In addition, in the information processing apparatus 100 using the touch screen, the user traces the trace of the touch screen using a pen or a finger as an operation input.

  The external memory 106 is detachably connected via the interface 104. The external memory 106 stores data indicating game play status (past results, etc.), data indicating game progress, chat communication log (record) data in the case of a network match, and the like. The external memory 106 can be rewritten. When the user inputs necessary instructions via the controller 105, these data are recorded in the external memory 106 as appropriate.

  As described above, it is possible to adopt a form in which the application program is installed in the external memory 106 and executed. This is suitable when the external memory 106 has a large capacity.

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

  The image processing unit 107 first processes the data read from the DVD-ROM by the CPU 101 or an image arithmetic processor (not shown) included in the image processing unit 107. Next, the image processing unit 107 records the image information obtained by the processing process in a frame memory (not shown). The frame memory is mounted on the image processing unit 107. Image information recorded in the frame memory is converted into a video signal at a predetermined synchronization timing, and is output to a monitor (not shown) connected to the image processing unit 107. Thereby, various image displays are possible.

  As a monitor of a portable image processing apparatus, a small liquid crystal display is typically used. When a touch screen is used as the controller 105, the display panel of the touch screen functions as a monitor. As a monitor of a game device for playing at home, a display device such as a CRT (Cathode Ray Tube) or a plasma display can be used.

  The image calculation processor can execute a two-dimensional image overlay calculation, a transmission calculation such as α blending, and various saturation calculations at high speed.

  It is also possible to execute a calculation for obtaining a rendered image at high speed. The rendering image is an image obtained by bird's-eye view of a polygon arranged in a virtual three-dimensional space from a predetermined viewpoint position in a predetermined line of sight. The rendered image is obtained by rendering polygon information, which is arranged in the three-dimensional space and to which various kinds of texture information are added, by the Z buffer method or the like.

  Further, the CPU 101 and the image arithmetic processor cooperate to perform drawing of a character string as a two-dimensional image according to font information. The font information defines the shape of the character. An image representing a character string is drawn on the frame memory or the surface of each polygon.

  The NIC 109 is an interface that mediates between an Internet connection device (not shown) and the CPU 101. The NIC 109 is used when the information processing apparatus 100 is connected to a computer communication network (not shown) such as the Internet. Internet-connected devices are based on the 10BASE-T / 100BASE-T standard used when configuring a LAN (Local Area Network), an analog modem for connecting to the Internet using a telephone line, ISDN (Integrated Services Digital) A network modem, an ADSL (Asymmetric Digital Subscriber Line) modem, a cable modem for connecting to the Internet using a cable television line, or the like may be used.

  An application program can be installed in the HD 121 or the like based on information obtained from the computer communication network via the NIC 109.

  The audio processing unit 110 converts audio data read from the HD 121 or DVD-ROM into an analog audio signal, and outputs the analog audio signal from a connected speaker (not shown). Also, under the control of the CPU 101, the sound processing unit 110 generates sound effects and music data to be generated during the progress of the game. Then, the sound processing unit 110 outputs sound corresponding to the generated sound effect and music data from a speaker, headphones (not shown), and earphones (not shown).

  When the audio data recorded on the HD 121 or the DVD-ROM is MIDI data, the audio processing unit 110 refers to the sound source data and converts the MIDI data into PCM data. Note that the audio processing unit 110 has MIDI sound source data. If the audio data is compressed audio data such as ADPCM format or Ogg Vorbis format, the audio processing unit 110 expands and converts it into PCM data. The PCM data is D / A (Digital / Analog) converted at a timing corresponding to the sampling frequency and output to a speaker, thereby enabling voice output.

  Furthermore, a microphone 111 can be connected to the information processing apparatus 100 via the interface 104. In this case, the information processing apparatus 100 performs A / D conversion on an analog signal from the microphone 111 at an appropriate sampling frequency. That is, the audio signal from the microphone 111 is converted into a PCM format digital signal. Therefore, the audio processing unit 110 can perform processing such as mixing.

  As described above, the information processing apparatus 100 used in the present embodiment typically uses a large-capacity external storage device such as the HD 121. The HD 121 can also perform the same functions as a DVD-ROM or the like mounted on the ROM 102, RAM 103, external memory 106, DVD-ROM drive 108, and the like.

  Furthermore, a camera 131 is connected to the information processing apparatus 100 used in the present embodiment. The camera 131 shoots the real world as a moving image and a still image. By photographing the facial expression and body posture of the user with the camera 131 and performing image recognition using the CPU 101 and dedicated hardware (not shown), the position and expression of the user's face and each part of the body The position of can be obtained. It is also possible to use various types of information obtained by image recognition instead of the instruction operation for the controller 105.

  In addition, a form in which a keyboard, a mouse, or the like is connected can also be employed. The keyboard receives a character string editing input from the user. The mouse then accepts various position designations and selection inputs. In addition, a general-purpose personal computer, a server computer, or the like can be used instead of the information processing apparatus 100 of the present embodiment.

  The information processing apparatus 100 described above corresponds to a consumer game apparatus. However, the electronic device capable of various input / output processes can realize the game device of the present invention. Therefore, the game device of the present invention can be realized on various computers such as a mobile phone, a mobile game device, a karaoke device, and a general business computer.

  For example, similarly to the information processing apparatus 100, the business computer has a CPU, RAM, ROM, DVD-ROM drive, NIC, and HD as components. The business computer includes an image processing unit having a simpler function than the information processing apparatus 100. In business computers, flexible disks, magneto-optical disks, magnetic tapes and the like can be used as external storage devices. In a business computer, a keyboard or a mouse is typically used as an input device instead of the controller 105.

  The game apparatus according to the present invention is realized by the CPU 101 executing the game program recorded on the DVD-ROM or the hard disk 121 in the information processing apparatus 100 and controlling each unit of the information processing apparatus 100. Is possible.

  Each unit of the game device according to the present invention can be realized by a dedicated electronic circuit or a reconfigurable electronic circuit such as an FPGA (Field Programmable Gate Array).

  Hereinafter, various aspects according to the present invention will be described. Hereinafter, in order to facilitate understanding, a case where a game program is realized in the information processing apparatus 100 will be taken as an example.

  FIG. 2 is an explanatory diagram showing a schematic configuration of the game device according to the present embodiment. Hereinafter, a description will be given with reference to FIG.

  The game device 201 according to the present embodiment includes a generation unit 202, an extraction unit 203, and a drawing unit 204, and is configured as follows.

  The game device 201 according to the present embodiment shows a state in which a plurality of objects arranged in a virtual space representing the game world are viewed from a viewpoint set in the virtual space in a line-of-sight direction set in the virtual space. When an image to be displayed is displayed on the screen, appropriate contour lines are drawn on the plurality of objects in the image.

  Hereinafter, for ease of understanding, the object in the virtual space and the image to be processed will be described as an example. However, the principle of the present invention is not limited to these objects and images, and may be changed as appropriate. Is possible.

  FIG. 3 is an explanatory diagram illustrating an example of objects arranged in the virtual space. Hereinafter, a description will be given with reference to FIG. Note that since this drawing is drawn by applying the normal rules for drafting, a contour line is drawn, but actually, the contour line itself does not exist in the virtual space.

  In the example shown in this figure, a sphere object 302 representing the character's head, a cylindrical object 303 representing the character's neck, and a plate object 304 disposed in the character's background are arranged in the virtual space 301. ing.

  In this example, the cylinder object 303 intersects with the sphere object 302, and the center axis 306 of the cylinder object 303 passes through a location that is shifted from the center 305 of the sphere object 302.

  The cylinder object 303 and the sphere object 302 are both white, but the plate object 304 has a different color. Therefore, the color of the plate object 304 is drawn by hatching.

  A state in which the objects 302, 303, and 304 are viewed from the viewpoint 307 set in the virtual space 301 in the direction of the line of sight 308 is drawn by perspective projection or parallel projection to represent the state in the virtual space. An image can be obtained.

  In this example, an environmental light source that is irradiated with light from all directions is assumed for easy understanding. However, one or a plurality of point light sources and parallel light sources may be arranged in the virtual space 301, It is also possible to use a combination of these light sources.

  In this example, a sphere, a cylinder, or a plate is used as the object, but a polygon (polygon) or a surface representing a curved surface can be used as the object.

  Information such as the positions and orientations and colors of the objects 302, 303, and 304, the position of the viewpoint 307, and the orientation of the line of sight 308 are stored in the RAM 103.

  That is, the generation unit 202 shows a state in which a plurality of objects arranged in the virtual space 301 representing the game world are viewed from the viewpoint set in the virtual space 301 in the line-of-sight direction set in the virtual space 301. A first image to represent is generated.

  FIG. 4 is an explanatory diagram illustrating an example of the first image. Hereinafter, a description will be given with reference to FIG.

  The first image 401 is a bitmap-format image in which pixels are arranged in a grid pattern vertically and horizontally. In this figure, the number of pixels is set to be extremely small for easy understanding, but the number of pixels can be arbitrarily changed. Further, in this drawing, for easy understanding, a frame line is drawn on the outer periphery of the first image 401, but a boundary line between pixels is not drawn (the same applies hereinafter).

  In the center of the first image 401, a spherical object 302 and a cylindrical object 303 are drawn in white. As described above, since an environmental light source is assumed, the boundary line between the two is not drawn. This makes it difficult to understand the outline of the character's jaw.

  A plate object 304 is visible at the periphery of the first image 401. That is, when the virtual space 301 is viewed from the viewpoint 306 in the direction of the line of sight 307, the field of view is covered with the plate object 304.

  In addition, since there is a difference between the sphere object 302 and the cylinder object 303 and the plate object 304, whether they are white or hatched, the boundary is known, but the outline is not drawn.

  Conventionally, when applying a contour line to the first image 401, a contour extraction filter is applied to the first image 401. This contour extraction filter corresponds to a high-pass filter.

  The simplest contour extraction filter regards a certain pixel as a contour when the difference in pixel value between a certain pixel and a pixel adjacent to the pixel exceeds a threshold value.

  Various variations of the contour extraction filter have been proposed depending on which pixels are compared and how the threshold value is set. In addition, there is a technique for adopting a difference in pixel values as the color density of an outline in the outline extraction filter.

  FIG. 5 is an explanatory diagram showing a conventional example in which a contour extraction filter is applied to the first image 401. Hereinafter, a description will be given with reference to FIG.

  The contour extraction filter according to this example is configured so that a certain pixel is contoured when a difference in pixel value between a certain pixel and a pixel on the right or lower side of the certain pixel exceeds a predetermined threshold value. .

  This figure shows a conventional image 451 obtained by simply applying a contour extraction filter to the first image 401 shown. In the image 451 of the conventional example, an outline 452 representing the boundary between the sphere object 302 and the plate object 304 and the boundary between the cylinder object 303 and the plate object 304 is drawn. This is because the color drawn in the first image 401 is different at the boundary.

  The reason why the contour 452 is asymmetrical is that the contour extraction filter applied in this example is asymmetrical.

  On the other hand, since the spherical object 302 and the cylindrical object 303 are drawn with the same color in the first image 401, the boundary cannot be obtained simply by applying the contour extraction filter.

  Therefore, in this embodiment, the following technique is adopted. That is, the generation unit 202 generates a second image in which a depth value representing a depth with respect to the viewpoint 307 at a position drawn at each pixel position in the first image 401 among the plurality of objects is a pixel value at each pixel position. To do.

  FIG. 6 is an explanatory diagram showing a state of the second image. Hereinafter, a description will be given with reference to FIG.

  As shown in the figure, the second image 501 is an image having the same size and width as the first image 401. The first image 401 can be a color image or a gray scale image, but the second image 501 is typically a gray scale image.

  In this figure, for easy understanding, white, gray, and black in a gray scale image are expressed by the hatching density of each pixel.

Each pixel in the second image 501 employs the depth of the portion of the object drawn in the pixel with respect to the viewpoint 307 as the pixel value. As the depth with respect to the viewpoint 307, the following can be adopted.
(A) The coordinate value on the Z-axis of the part of the object drawn on the pixel when the viewpoint 307 is the origin and the coordinate axis extending in the line-of-sight direction is the Z-axis. This is the so-called Z value.
(B) The distance between the viewpoint 307 and the part of the object drawn in the pixel.
(C) In (a) and (b) above, not the object portion drawn in the pixel but the representative point of the object (the point that determines the position of the object in the virtual space 301 such as the center point and the center of gravity). The mode to adopt. That is, the Z value of the representative point of the object drawn on the pixel and the distance between the representative point of the object and the viewpoint 307.

  That is, as the depth, any numerical parameter can be adopted as long as it is a numerical parameter indicating how far each object is from the viewpoint 307 or how close each object is.

  Each pixel value takes an integer value of 0 to 255 in a grayscale image that expresses light and dark with 8 bits, and any integer value of 0 to 65535 in a grayscale image that expresses light and dark with 16 bits. Take. Even when the second image 501 is expressed by another number of bits, each pixel value generally takes any value between 0 and the upper limit value.

  Therefore, the depth of the object seen from the viewpoint 307 in the direction of the line of sight 308 is appropriately mapped between the above 0 to the upper limit value.

  Most simply, the depth from the nearest point closest to the viewpoint to the farthest point farthest from the viewpoint among the parts of the object seen from the viewpoint 307 to the line of sight 308 is evenly between the above 0 to the upper limit value. A method of allocating to is considered.

  Further, when the first image 401 is generated using the 3D graphics technique, an object to be drawn among objects arranged in the virtual space may be selected within a depth range. . In this case, the lower limit to the upper limit of the depth range may be equally allocated from 0 to the upper limit value of the pixel value.

  In this figure, the example which employ | adopted said (a) is displayed. Therefore, the plate object 304 is drawn with thin hatching that is close to white because it is far from the viewpoint 307, and the sphere object 302 and the cylinder object 303 are close to the viewpoint 307, and thus are closer to black than the plate object 304. It is drawn with dark hatching.

  Also, since the spherical object 302 is closer to the viewpoint 307 than the cylindrical object 303, there is a difference in hatching density between the two.

  Therefore, in the present embodiment, the contour is obtained by using the difference in depth.

  That is, in the present embodiment, the extraction unit 203 obtains a third image by applying a contour extraction filter to the second image 501.

  FIG. 7 is an explanatory diagram illustrating a state of a third image obtained by applying a contour extraction filter to the second image 501. Hereinafter, a description will be given with reference to FIG.

  As described above, the contour extraction filter is a filter that regards a portion having a large difference in pixel values as a contour. Therefore, when the contour extraction filter used in the conventional example of FIG. 4 is applied to the second image 501, a portion having a different depth with respect to the viewpoint 307 is extracted as a contour.

  As shown in this figure, the outline 602 extracted from the third image 601 draws all boundaries between the three objects of the sphere object 302, the cylinder object 303, and the plate object 304.

  That is, in the third image 601 of this figure, as the contour 602, the contour 602c of the character's jaw is drawn in addition to the contour 602a of the character's head and the contour 602b of the character's neck.

  As described above, contour extraction is impossible in the conventional example and can be performed by performing simple image processing in the present embodiment.

  Finally, the drawing unit 204 obtains a fourth image by drawing a contour 602 represented by the third image 601 with the first image 401 as a background.

  FIG. 8 is an explanatory diagram showing a state of a fourth image obtained by drawing the contour 602 represented by the third image 601 by overwriting the first image 401. Hereinafter, a description will be given with reference to FIG.

  As shown in the figure, in the fourth image 701, an outline 602 is drawn at the boundary between the sphere object 302, the cylinder object 303, and the plate object 304 drawn in the first image 401.

  In this drawing, black is used as the contour 602 for drawing. However, in the method for determining only whether a pixel corresponds to the contour 602 as in the present example, the contour of the first image 401 is contoured. The color when drawing 602 can be any color.

  In addition, in the aspect in which the darkness of the contour 602 is set, the contour can be drawn by a method of darkening the brightness of the pixel value of the first image 401 according to the darkness of the contour 602. That is, it is an aspect in which the place where the difference in perspective is large is dark and the color is almost unchanged in the place where the difference in perspective is small.

  Further, in the aspect of setting the darkness of the contour 602, when the contour 602 is drawn in the fourth image 701, the color of the contour 602 is determined in advance, and the darkness of the contour 602 is adopted as “opacity”. The outline may be drawn by α blending with the first image 401.

  Note that the above-described method of darkening the brightness of the pixel according to the density of the contour corresponds to a method of α blending with the first image 401 by setting the color of the contour 602 to black.

  FIG. 9 is a flowchart showing the flow of processing control according to this embodiment. Hereinafter, a description will be given with reference to FIG.

  This process is started when the information processing apparatus executes a program for realizing the game apparatus 201 according to the present embodiment.

  When this processing is started, the generation unit 202 of the game apparatus 201 generates a first image 401 and a second image 501 from various information in the virtual space stored in the RAM 103 or the like (steps). S801).

  The generation unit 202 may generate the first image 401 first and then the second image 501, but it is typical to generate the first image 401 and the second image 501 in parallel. .

  In the present embodiment, the generation unit 202 is realized by the operation of the image processing unit 107 under the control of the CPU 101, and the first image 401 and the second image 501 are output to the RAM 103.

  Depending on the configuration of the information processing apparatus 100, the output destination of the image output by the image processing unit 107 such as the first image 401 and the second image 501 is closely linked to the image processing unit 107 in the RAM 103. By using the dedicated video RAM area and frame buffer area configured for image processing, the processing speed can be increased.

  Next, the extraction unit 203 of the game device 201 applies a contour extraction filter to the second image 501 to obtain a third image 601 (step S802).

  Here, the extraction unit 203 is realized by the operation of the image processing unit 107 with respect to the second image 501 stored in the RAM 103 under the control of the CPU 101, and is an application result of the contour extraction filter. The third image 601 is output to the RAM 103.

  Finally, the drawing unit 204 of the game apparatus 201 draws a contour 602 represented by the third image 601 on the first image 401, thereby obtaining a fourth image 701 (step S803).

  In the present embodiment, the drawing unit 204 refers to the first image 401 and the third image 601 stored in the RAM 103 under the control of the CPU 101, and the image processing unit 107 adds the contour 602 to the first image 401. A fourth image 701 that is realized by drawing and obtained as a result of the drawing is output to the RAM 103.

  According to the present embodiment, outlines that could not be extracted conventionally can be appropriately extracted by simple image processing.

  This example is a preferred embodiment in which the first image 401 and the second image 501 are generated in parallel in the above example.

  FIG. 10 is a flowchart illustrating a flow of control of generation processing of the first image 401 and the second image 501 according to the present embodiment. Hereinafter, a description will be given with reference to FIG.

  The generation process shown in this figure corresponds to step S801 in the flowchart shown in FIG.

  When this process is started, the CPU 101 secures a first image buffer for the first image 401 and a second image buffer for the second image 501 in the RAM 103 (step S811).

  For example, if the first image 401 is 24-bit color, the second image 501 is 8-bit grayscale, and the size is horizontal w dots and vertical h dots, 3 × w × h bytes for the first image 401 For the second image 501, a memory area of w × h bytes is required.

  Next, the CPU 101 clears the first image buffer and the second image buffer (step S812).

  The first image buffer is initialized with a pixel value representing a predetermined background color, for example, a color representing infinity. The second image buffer is initialized with a value representing the farthest depth, that is, the maximum pixel value of the second image 501. For example, when the second image 501 is drawn on an 8-bit gray scale, the maximum pixel value of the second image 501 is 255.

  Then, based on the information stored in the RAM 103, the following processing is repeated for each object to be drawn arranged in the virtual space 301 (step S813).

  First, based on the position of the viewpoint 306 and the direction of the line of sight 307, a region where the object is projected in the first image 401 is calculated (step S814).

  Next, the following processing is repeated for each pixel position of the pixel in the region (step S815).

  First, the depth of the portion of the object that is projected at the pixel position of the pixel currently focused on in repetition is acquired (step S816).

  As described above, the depth of the projection part of the object includes the Z value of the projection part, the distance between the projection part and the viewpoint 306, the Z value of the representative point of the object, or the representative point and viewpoint 306 of the object. The distance can be adopted.

  Then, the obtained depth is mapped to an integer value from 0 to the maximum pixel value in the second image 501 to obtain a depth value (step S817).

  Next, the pixel value of the pixel position in the second image buffer is acquired (step S818).

  Then, it is determined whether the depth value obtained as a result of mapping is smaller than the obtained pixel value in the second image buffer (step S819).

  If the mapping value is smaller (step S819; Yes), the object is closer to the viewpoint than the objects drawn so far. Therefore, the pixel value of the color of the object is written to the pixel position in the first image buffer (step S820), the depth value is written to the pixel position in the second image buffer (step S821), and the process goes to step S822. move on.

  On the other hand, when the value obtained as a result of mapping is equal to or greater than the pixel value in the acquired second image buffer (step S819; No), the object is closer to the viewpoint than the object drawn so far. I can't say that. Therefore, the process proceeds to step S822 as it is.

  This process is repeated for the pixel positions of all the pixels in the area (step S822).

  When the repetitive processing from step S815 to step S822 is completed, the drawing of the object is completed.

  Therefore, the processing so far is repeated for all the objects to be rendered (step S823).

  When the repetitive processing from step S813 to step S823 is completed, drawing of all objects is completed, and the first image 401 is generated in the first image buffer, and the second image 501 is generated in the second image buffer. Yes.

  In the three-dimensional graphics, a method of sorting objects in the Z-axis direction in advance using information corresponding to the depth value and drawing in order from the far side may be used, but this embodiment may be combined with this aspect. Is possible. Even when objects are not sorted based on perspective in the Z-axis direction, it is possible to appropriately determine which object hides which object.

  According to this aspect, the object can be appropriately drawn on the first image 401 particularly when the perspective is determined for each part of the object projected onto the pixel.

  In addition, since information used for perspective determination when the first image 401 is drawn can be used as it is as the second image 501, memory and calculation time can be saved.

  This embodiment corresponds to one of the preferred embodiments of the depth value calculation in the above-described example.

  That is, in the present embodiment, as the depth value for each pixel position, the inner product of the vector from the viewpoint 307 to the location projected on the pixel position of the object and the unit vector in the line-of-sight direction, It is obtained by applying a monotonically increasing function having a range of integers that can be taken by pixel values.

  Here, the inner product of the vector from the viewpoint 307 toward the projected part of the object and the unit vector in the direction of the line of sight 308 corresponds to a so-called Z value.

  In addition, as a method for mapping the Z value to an integer value of 0 to 255 or an integer value of 0 to 65535, in a general 3D graphics method, the side closer to the viewpoint is fine, and the side far from the viewpoint is Rough allocation is common.

  On the other hand, when the colors of the objects are approximate and arranged at close positions, the Z value is also close. Therefore, in such a case, the depth range of the object to be drawn can be set, and the range from the nearest depth to the farthest depth can be equally allocated.

  In addition, when it is desired to draw a specific character neatly, an object constituting the character and other objects are classified to obtain a depth range including the object constituting the character. For example, a predetermined range before and after the Z value of the representative point of the character is set as the depth range.

  Then, a technique such as finely allocating the depth range and roughly allocating the other ranges may be adopted.

  In any method, the depth value is a value that increases as the distance from the viewpoint 307 increases, that is, as the Z value increases. Therefore, the conversion from the Z value to the depth value is obtained by applying a monotonically increasing function (monotonic non-decreasing function).

  As described above, the depth value is used when an object is drawn by three-dimensional graphics. Therefore, when the image processing unit 107 is realized by dedicated hardware, the first image 401 is generated in the RAM 103 when the object, the viewpoint 306, the line of sight 307 information, and the mapping allocation information are given. As a side effect, the second image 501 may be generated.

  In such an aspect, in particular, the first image 401 and the second image 501 can be generated at high speed.

  In the description of the above embodiment, when the difference in pixel value between a certain pixel in the second image 501 and the pixel on the right side or the lower side of the certain pixel exceeds a predetermined threshold as the contour extraction filter, What used a certain pixel as an outline was adopted.

  Hereinafter, in order to facilitate understanding, the sizes of the first image 401, the second image 501, the third image 601, and the fourth image 701 are all assumed to be a width w and a height h, and the horizontal coordinate values are set. x (0 ≦ x <w), the pixel value at the position (x, y) of the vertical coordinate value y (0 ≦ y <h), respectively, s [x, y], d [x, y], r [x, y] and g [x, y] are assumed, the x-axis extends from left to right, and the y-axis extends from top to bottom.

  However, depending on the mode, the axis direction may be reversed.

  When the first image 401 and the fourth image 701 are color images, s [x, y] and g [x, y] are typically three-element vector values in RGB representation.

  Further, since the second image 501 is a gray scale image, d [x, y] is typically a scalar value.

  The pixel value s [x, y] of the third image 601 is also typically a scalar value.

  Also, let M be the maximum pixel value in a grayscale image. In the 8-bit gray scale, M = 255, and in the 16-bit gray scale, M = 65535.

  When the pixel value of a certain pixel in the grayscale image is v, the pixel value obtained by negative / positive conversion is Mv. Therefore, the third pixel 601 has a contour pixel as negative expression (a pixel value is large, a dark pixel). The positive expression (pixel value is small, bright pixel) can be arbitrarily selected. In FIG. 7, negative expression is adopted and a contour 602 is drawn in black (dark pixels).

  In the following, in order to facilitate understanding, explanation will be given in negative expression, but it is also easy to implement in positive expression by the above conversion formula.

  Now, the contour extraction filter employed in the above embodiment obtains the pixel value r [−, −] of the third image 601 from the pixel value d [−, −] of the second image 501 as follows. Is.

That is, for 0 ≦ x <w-1 and 0 ≦ y <h-1,
r [x, y] = M (| d [x, y] -d [x + 1, y] |> T or | d [x, y] -d [x, y + 1] |> T)
= 0 (other than above)
For 0 ≦ y <h,
r [w-1, y] = 0,
For 0 ≦ x <w and y = h-1,
r [x, h-1] = 0,
However, T is a predetermined threshold value.

First of all, for all 0 ≦ x <w and 0 ≦ y <h,
r [x, y] ← 0
Then, for each of 0 ≦ x <w−1 and 0 ≦ y <h−1, “| d [x, y] -d [x + 1, y] |> T or | d [x, y] -d [x, y + 1] |> T ”
r [x, y] ← M
Is the same as

  In this contour extraction filter, the size of the contour with respect to the drawing result of an object is substantially the same as the size of the drawing result of the object, but the contour is drawn as shown in FIGS. Are extracted with a slight shift to the upper left.

In addition, there is a method of drawing the outline outside the drawing result of the object. The first technique is to extract the left and right contours of the object. That is, for all 0 ≦ x <w and 0 ≦ y <h,
r [x, y] ← 0
When d [x, y]> d [x + 1, y] + T is satisfied for each of 0 ≦ x <w-1 and 0 ≦ y <h
r [x, y] ← M
When d [x, y] + T <d [x + 1, y] is satisfied
r [x + 1, y] ← M
Is substituted as follows.

  In this method, only an operation in the left-right direction is performed, and the outline of the object is extracted outside the drawing area of the object.

  FIG. 11 is an explanatory diagram showing a third image 601 in which contours are extracted from the left and right by threshold comparison. Hereinafter, a description will be given with reference to FIG.

  As shown in this figure, in the third image 601, contours 602 are extracted in the horizontal direction, and the contours 602 are interrupted at the top and bottom of the character's top and bottom.

The second method is to extract the upper and lower contours of the object. That is, for all 0 ≦ x <w and 0 ≦ y <h,
r [x, y] ← 0
When d [x, y]> d [x, y + 1] + T is satisfied for each of 0 ≦ x <w and 0 ≦ y <h−1
r [x, y] ← M
When d [x, y] + T <d [x, y + 1] holds
r [x, y + 1] ← M
Is substituted as follows.

  In this method, only the operation in the vertical direction is performed, and the outline of the object is extracted outside the drawing area of the object.

  FIG. 12 is an explanatory diagram showing a third image 601 in which contours are extracted from above and below by threshold comparison. Hereinafter, a description will be given with reference to FIG.

  As shown in the figure, in the third image 601, a contour 602 is extracted in the vertical direction, and the contour 602 is interrupted on the left and right sides of the character.

  The third method applies both the first method and the second method.

  FIG. 13 is an explanatory diagram showing a third image 601 in which contours are extracted from the top, bottom, left and right by threshold comparison, and FIG. 14 is an explanatory diagram showing a fourth image 701 obtained using the contours extracted from top, bottom, left and right. is there. Hereinafter, a description will be given with reference to FIG.

  As shown in the figure, in the third image 601, the contour 602 is extracted in both the horizontal and vertical directions, and the contour 602 is not interrupted.

  In the fourth image 701, the contour 602 is attached to the left and right targets on the outside of the spherical object 302 and the cylindrical object 303.

  In the above method, in order to extract the contours on the left and right outer sides and the upper and lower outer sides, the substitution destination of the pixel value representing the contour is set as r [x, y] based on the comparison result of the magnitude relationship. Switching between r [x + 1, y] or between r [x, y] and r [x, y + 1] is performed, but depending on the configuration of the image processing unit 107, substitution may be performed. By setting all points to r [x, y], high-speed calculation may be possible. The assignment destination can also be selected in the following manners.

  In these methods, when the depth difference between adjacent pixels is larger than the threshold T, a contour is extracted by giving a maximum value M to a pixel far from the viewpoint 307.

The color in which these contours are drawn in the fourth image 701 is c (RGB vector value). Then, for all 0 ≦ x <w and 0 ≦ y <h,
g [x, y] = s [x, y] (r [x, y] = 0);
= c (r [x, y]> 0)
The fourth image 701 can be generated by executing the above.

  In addition, when (r [x, y] = M) with respect to the first image buffer in which the first image 401 is stored, the color c is overwritten on the pixel position (x, y), thereby obtaining the fourth image. 701 may be generated.

In addition, for all 0 ≦ x <w and 0 ≦ y <h,
g [x, y] = (Mr [x, y]) / M × s [x, y] + r [x, y] / M × c
As described above, the fourth image 701 may be generated by using (Mr [x, y]) / M or r [x, y] / M as a parameter representing transparency.

  The first method to the third method can be appropriately selected according to the usage, the amount of calculation, the direction in which the object moves, the shape of the character constituted by the object, and the like.

  In the above-described embodiment, the contour is extracted by comparing the difference between the pixel values and the threshold value, but it is also possible to assume the darkness of the contour.

  That is, first, as in the fourth embodiment, the initial value of the pixel value at each pixel position in the third image 601 is set to zero.

After this, as a method similar to the first method of Example 4,
If each pixel position in the second image 501 is scanned from left to right and adjacent pixel positions are scanned, and the pixel value at the left pixel position is larger than the pixel value at the right pixel position, the pixel value at the left pixel position And the pixel value at the left pixel position in the third image 601 with the difference between the pixel value at the right pixel position and the pixel value at the right pixel position,
If each pixel position in the second image 501 is scanned from right to left and adjacent pixel positions are scanned, and the pixel value at the right pixel position is larger than the pixel value at the left pixel position, the pixel value at the right pixel position There is a method of updating the pixel value at the right pixel position in the third image 601 by the difference between the pixel value at the left pixel position and the pixel value at the left pixel position.

In this method, if d [x, y]> d [x + 1, y] holds for each of 0 ≦ x <w-1 and 0 ≦ y <h
r [x, y] ← d [x, y] -d [x + 1, y]
When d [x, y] <d [x + 1, y] is satisfied
r [x + 1, y] ← d [x + 1, y] -d [x, y]
Substitute as follows.

In addition, as a method similar to the second method of Example 4,
If each pixel position in the second image 501 is scanned from top to bottom and adjacent pixel positions are scanned, and the pixel value at the upper pixel position is greater than the pixel value at the lower pixel position, the pixel value at the upper pixel position And the pixel value at the upper pixel position in the third image 601 with the difference between the pixel value at the lower pixel position and the pixel value at the lower pixel position,
If each pixel position in the second image 501 is scanned from the bottom to the top and adjacent pixel positions are scanned, and the pixel value at the lower pixel position is larger than the pixel value at the upper pixel position, the pixel value at the lower pixel position There is also a method of updating the pixel value at the lower pixel position in the third image 601 by the difference between the pixel value at the upper pixel position and the pixel value at the upper pixel position.

In this method, if d [x, y]> d [x, y + 1] holds for each of 0 ≦ x <w and 0 ≦ y <h−1
r [x, y] ← d [x, y] -d [x, y + 1]
When d [x, y] <d [x, y + 1] holds
r [x, y + 1] ← d [y + 1] -d [x, y]
Substitute as follows.

  Furthermore, as in the third method of the fourth embodiment, these can be combined.

  In these methods, the contour density is expressed in multiple stages from 0 to M.

  In addition, when the difference between adjacent pixels is smaller than a predetermined threshold, a method may be adopted in which substitution of the difference is not executed.

  As such a threshold value, for example, the result of dividing the difference between the largest depth value and the smallest depth value in the second image 501 by a predetermined constant (for example, 2, 3, 4, 5, etc.) Can be adopted.

  Note that when the threshold is not used for the difference, the third image 301 is similar to a shaded shadow based on the unevenness of the object. The image 301 is similar to the image drawn as a shadow only in a portion that is somewhat dark.

  FIG. 15 is an explanatory diagram showing the contours extracted from the top, bottom, left, and right in consideration of the darkness. Hereinafter, a description will be given with reference to FIG. In this figure, the color density (darkness) is expressed by hatching density.

  As shown in the figure, since the sphere object 302 and the plate object 304 are largely separated from each other and the cylinder object 303 and the plate object 304 are separated greatly, the boundary between the sphere object 302 and the plate object 304 in the outline 602 is shown. In addition, the boundary between the cylinder object 303 and the plate object 304 is dark and dark.

  In the contour 602, the jaw between the spherical object 302 and the cylindrical object 303 is thin and bright.

  Furthermore, in this example, a threshold value is provided for the difference. In the spherical object 302 and the cylindrical object 303, the depth value difference is smaller than the threshold value, so that it is not recognized as an outline and is drawn in white.

In this way, when using the contour 602 from which the darkness is obtained, assuming that the basic color of the contour 602 is c (RGB vector value), 0 ≦ x <w and 0 ≦ y <h,
g [x, y] = (Mr [x, y]) × s [x, y] + r [x, y] × c
By executing the above, it is possible to generate a fourth image 701 having a translucent outline.

  Here, when c = (0,0,0), that is, when the basic color of the contour 602 is black, for each pixel position (x, y) of the fourth image 701, the pixel position (x, y) ) Is a color obtained by darkening the color represented by the pixel value s [x, y] in the first image 401 with the intensity represented by the pixel value r [x, y] in the third image 601 at the pixel position. The pixel value (Mr [x, y]) × s [x, y] to be represented is used as the pixel value at the pixel position in the fourth image.

other than this,
g [x, y] = s [x, y] (r [x, y] = 0);
= (Mr [x, y]) × c (r [x, y]> 0)
As a result, a fourth image 701 depicting an opaque outline may be generated.

This is for each pixel position of the fourth image 701.
(A) If the pixel value r [x, y] in the third image 601 at the pixel position (x, y) is 0, the pixel value s [x in the first image 401 at the pixel position (x, y) , y] is a pixel value s [x, y] at the pixel position in the fourth image 701,
(B) If the pixel value r [x, y] in the third image 601 at the pixel position (x, y) is not 0, the pixel value r [x, y] has a predetermined hue and saturation, and the third image 601 at the pixel position A pixel value (Mr [x, y]) × c representing a color having a pixel value r [x, y] as a darkness is set as a pixel value g [x, y] at the pixel position in the fourth image 701. It corresponds to.

  FIG. 16 is an explanatory diagram illustrating a state of the fourth image 701 generated using a dark and opaque outline. Hereinafter, a description will be given with reference to FIG.

  In the outline 602 of the fourth image 701 shown in this figure, a white portion (corresponding to r [x, y] = 0) in FIG. 13 is not drawn on the first image 401, and a colored portion (r [x, y]> 0) is drawn on the first image 401 as it is, and the contour 602 is shaded.

  According to this method, the contour density can be naturally expressed by simple calculation.

  In this embodiment, the difference between the pixel values of adjacent pixels is used as it is as the darkness of the contour 602 in the third image 601, but a monotonically increasing function having an integer from 0 to M as the range of the difference. A value obtained by applying (monotonic non-increasing function) may be adopted as the density of the contour 602 in the third image 601.

In addition, when using an image processing calculation function prepared by the image processing unit 107, a method of drawing an outline as described below may be employed. That is,
clamp01 (x) = 0 (x ≦ 0);
= x (0 <x <1);
= 1 (1 ≦ x)
Based on function clamp01 (x), parameter K, threshold threshold, parameter c_scale
opacity = clamp01 (clamp01 (K × (| d [x, y] -d [x + 1, y] | +
| d [x, y] -d [x, y + 1] |)-
threshold) × c_scale
To calculate the parameter opacity.

  Here, the parameter K adjusts how much the difference between the pixel values is emphasized, the threshold threshold is a value that determines whether or not to draw an outline, and the parameter c_scale is in the range of 0 to 1 It adjusts the darkness of the contour.

And using the calculated opacity,
g [x, y] = (1-opacity) × s [x, y] + opacity × c
And

  In this way, when providing the darkness to the contour in accordance with the difference in pixel values, various darkness setting techniques can be employed such that the contour becomes darker as the difference increases.

  As described above, according to the present invention, a game device suitable for drawing an outline of an object arranged in a virtual space representing the game world, a game device control method, and these are realized by a computer. A program can be provided.

100 Information processing apparatus 101 CPU
102 ROM
103 RAM
104 Interface 105 Controller 106 External Memory 107 Image Processing Unit 108 DVD-ROM Drive 109 NIC
110 Audio processing unit 111 Microphone 121 HD
131 Camera 201 Game Device 202 Generation Unit 203 Extraction Unit 204 Drawing Unit 301 Virtual Space 302 Spherical Object 303 Cylindrical Object 304 Plate Object 305 Center of Spherical Object 306 Center Axis of Cylindrical Object 307 Viewpoint 308 Gaze 401 First Image 451 Conventional Image 452 Conventional example 501 Second image 601 Third image 602 Outline 701 Fourth image

Claims (10)

A first image representing a state in which a plurality of objects arranged in a virtual space representing the game world are viewed from a viewpoint set in the virtual space in a line-of-sight direction set in the virtual space; and the plurality of objects A generation unit that generates a second image having a depth value representing a depth with respect to the viewpoint at a position drawn at each pixel position in the first image as a pixel value at each pixel position,
An extraction unit that obtains a third image by applying a contour extraction filter to the second image;
A game apparatus comprising: a drawing unit that obtains a fourth image by drawing a contour represented by the third image with the first image as a background. The game device according to claim 1,
The generator is
The maximum value that the pixel value of the second image can take is an initial value of the pixel value at each pixel position in the second image,
For each of the plurality of objects,
(A) Find the area where the object is projected,
(B) For each pixel position in the obtained area, if the pixel value in the second image at the pixel position is smaller than the depth value for the position projected on the pixel position of the object, the position is The pixel value projected to the pixel position is obtained, the pixel value at the pixel position in the first image is updated to the obtained pixel value, and the pixel value at the pixel position in the second image is changed to the object value. The game apparatus, wherein the first image and the second image are generated by repeating the process of updating to a depth value. The game device according to claim 2,
The depth value for each pixel position is the pixel value of the second image, which is the inner product of the vector from the viewpoint to the portion of the object projected onto the pixel position and the unit vector in the line-of-sight direction. It is obtained by applying a monotonically increasing function whose range is an integer of a possible range. The game device according to claim 3,
The contour extraction filter is:
The initial value of the pixel value at each pixel position in the third image is set to 0,
If each pixel position in the second image is scanned from left to right and adjacent pixel positions are scanned, and the pixel value at the left pixel position is greater than the pixel value at the right pixel position, the pixel value at the left pixel position And the pixel value of the left pixel position in the third image is updated with the difference between the pixel value of the right pixel position and the pixel value of the right pixel position,
If each pixel position in the second image is scanned from right to left and adjacent pixel positions are scanned, and the pixel value at the right pixel position is greater than the pixel value at the left pixel position, the pixel value at the right pixel position The pixel value at the right pixel position in the third image is updated by the difference between the pixel value at the left pixel position and the pixel value at the left pixel position. The game device according to claim 4,
The contour extraction filter further includes:
If each pixel position in the second image is scanned from top to bottom and adjacent pixel positions are scanned, and the pixel value at the upper pixel position is greater than the pixel value at the lower pixel position, the pixel value at the upper pixel position And the pixel value at the upper pixel position in the third image is updated with the difference between the pixel value at the lower pixel position and the pixel value at the lower pixel position,
If each pixel position in the second image is scanned from the bottom to the top and adjacent pixel positions are scanned, and the pixel value at the lower pixel position is larger than the pixel value at the upper pixel position, the pixel value at the lower pixel position And a pixel value at the lower pixel position in the third image is updated by a difference between the pixel value at the upper pixel position and the pixel value at the upper pixel position. The game device according to claim 4 or 5, wherein
The contour extraction filter is obtained by applying a monotonically increasing function whose range is an integer of a range that can be taken by the pixel value of the third image, instead of the difference between the pixel values of the adjacent pixel positions. A game apparatus, wherein the pixel value in the third image is updated with a value. The game device according to any one of claims 4 to 6,
The drawing unit, for each pixel position of the fourth image,
(A) If the pixel value in the third image at the pixel position is 0, the pixel value in the first image at the pixel position is set as the pixel value at the pixel position in the fourth image;
(B) If the pixel value in the third image at the pixel position is not 0, the pixel has a predetermined hue and saturation and represents a color having the pixel value in the third image at the pixel position as darkness A game apparatus, wherein the value is a pixel value of the pixel position in the fourth image. The game device according to any one of claims 4 to 6,
For each pixel position of the fourth image, the drawing unit displays the color represented by the pixel value in the first image at the pixel position, and the intensity represented by the pixel value in the third image at the pixel position. A game apparatus characterized in that a pixel value representing a darkened color is used as a pixel value at the pixel position in the fourth image. A control method executed by a game device having a generation unit, an extraction unit, and a drawing unit,
A first image representing a state in which the generation unit viewed a plurality of objects arranged in a virtual space representing a game world from a viewpoint set in the virtual space in a line-of-sight direction set in the virtual space; A generation step of generating a second image having a depth value representing a depth with respect to the viewpoint at a position drawn at each pixel position in the first image among the plurality of objects as a pixel value at each pixel position;
An extraction step in which the extraction unit obtains a third image by applying a contour extraction filter to the second image;
A control method comprising: a drawing step in which the drawing unit obtains a fourth image by drawing a contour represented by the third image with the first image as a background. Computer
A first image representing a state in which a plurality of objects arranged in a virtual space representing the game world are viewed from a viewpoint set in the virtual space in a line-of-sight direction set in the virtual space; and the plurality of objects A generation unit that generates a second image having a depth value representing a depth with respect to the viewpoint at a position drawn at each pixel position in the first image as a pixel value at each pixel position,
An extraction unit that obtains a third image by applying a contour extraction filter to the second image;
A program that functions as a drawing unit that obtains a fourth image by drawing a contour represented by the third image with the first image as a background.

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