JP2005122719A - Computer graphics system, computer graphics reproduction method and program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a computer graphics system, a computer graphics reproduction method and a program that can easily produce an image of good texture. <P>SOLUTION: The computer graphics system 10 has a database part 12 registering at least one set of information about a lighting member for controlling light incident on an object positioned in a virtual space and optical characteristic information on optical characteristics of the lighting member, inputting means 14 for directively inputting form information and surface information about an object to be created in the virtual space, position information about the object in the virtual space, light source information about a light source, viewpoint information to be displayed as a two-dimensional image, and information on the type of the lighting member and the arrangement position thereof in the virtual space, and an arithmetic part 20 for generating image data on the object to be displayed as a two-dimensional image on the screen of a display device according to the information input by the inputting means 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a computer graphics system and a computer graphics reproduction method capable of reproducing the lighting of a photo studio for taking commercial photographs (commercial photographs) and the like and creating computer graphics images with excellent texture description. And programs.

Conventionally, in computer graphics (hereinafter also referred to as CG) for displaying a three-dimensional object image on a display screen, from the surface of an object mapped to the three-dimensional coordinates of a virtual space (simulation space) of CG. Light reflected in the observer's direction (viewpoint) is calculated using the ray tracing method (ray tracing method), etc. From this, the brightness of the image of the object observed by the observer is calculated and displayed. Is generally converted into a two-dimensional image corresponding to the luminance information displayed on the display and displayed on the display. In addition, in order to obtain a more realistic image, various methods for displaying an image in consideration of multiple reflections between objects, scattering of an object surface, and the like have been performed.
In this conventional CG, types of light sources such as a point light source, a line light source, and a surface light source are registered as light sources, and the position of the light source and the spectral radiation intensity can be set.

In addition, a CG system that can easily change the illumination effect of a display image is disclosed (see Patent Document 1 and the like).
In the CG system disclosed in Patent Document 1, the user can directly set the lighting effect in the display image, for example, the highlight position, the brightness of the highlight position, and the like by the input means. Thus, in the CG system of Patent Document 1, the direction, position, brightness, and the like of the light source are automatically calculated to realize the lighting effect, and the lighting effect of the display image is changed. You can easily get what you want.

Japanese Patent Laid-Open No. 7-129795

  However, in conventional CG, in order to obtain an image with high texture description such as transparency, stereoscopic effect, or glossiness of an object as in commercial photography, the texture is high simply by setting the type and position of the light source. There is a problem that images cannot be obtained and know-how is required. Furthermore, there is a problem that trial and error are necessary to obtain an image having a high texture.

  On the other hand, in the CG system disclosed in Patent Document 1, it is said that the highlight position can be set directly to obtain the lighting effect desired by the user. However, just adjusting the position of the highlight and the brightness at that position is not sufficient to obtain an image with a high texture description such as transparency, stereoscopic effect, or glossiness of the object. There is a problem that it is difficult to obtain an image having

  An object of the present invention is to provide a computer graphics system, a computer graphics reproduction method, and a program capable of solving the problems based on the conventional technology and easily obtaining an image with a high texture.

  In order to achieve the above object, according to a first aspect of the present invention, there is provided a computer graphics for displaying a three-dimensional image of an object created in a virtual three-dimensional coordinate space as a two-dimensional image of the object on a screen of a display device. A system comprising: lighting member information of a lighting member that adjusts light incident on the object arranged in the virtual three-dimensional coordinate space; and optical characteristic information related to the optical characteristics of the lighting member in combination. One registered database unit, shape information of the object to be created in the virtual three-dimensional coordinate space, surface information of the object, position information of the object in the virtual three-dimensional coordinate space, the virtual 3 Light source information of a light source provided in a three-dimensional coordinate space, viewpoint information for displaying as the two-dimensional image, and the lighting unit An input means for instructing and inputting the type of the object and the arrangement position information in the virtual three-dimensional coordinate space, the shape information of the object, the surface information of the object, the position information of the object, the light source information, the viewpoint information, A calculation unit that generates image data of the object to be displayed on the screen as a two-dimensional image based on the writing member information, the optical characteristic information of the writing member, and the arrangement position information of the writing member. A computer graphics system is provided.

In the present invention, the input unit further includes an input unit that inputs and instructs at least one of information on a light source provided in the virtual three-dimensional coordinate space and the lighting member information, and the input unit includes: It is preferable that the instruction is displayed on the screen.
In the present invention, the lighting member is preferably a diffuse transmission plate or a reflection plate.

Furthermore, in the present invention, for example, the optical characteristic of the lighting member can be represented by a bidirectional reflectance distribution function or a transmittance distribution function.
Furthermore, in the present invention, it is preferable that the light source information includes information on a form of the light source and position information in the virtual three-dimensional coordinate space.

  The second aspect of the present invention is a computer graphics reproduction method for displaying a three-dimensional image of an object created in a virtual three-dimensional coordinate space as a two-dimensional image of the object on a screen of a display device, Setting the shape information of the object, the surface information of the object, and the position information of the object in the virtual three-dimensional coordinate space; the form information of the light source provided in the virtual three-dimensional coordinate space; and the virtual three-dimensional coordinate space A step of setting light source information including arrangement position information indicating an arrangement position of the light source, lighting member information of a lighting member that adjusts light incident on the object, optical characteristic information relating to optical characteristics of the lighting member, and Setting the lighting member position information indicating an arrangement position of the lighting member in a virtual three-dimensional coordinate space; A step of modeling the object based on the determined shape information of the object, model data of the object obtained by the modeling process, the light source information, the lighting member information, and the optical characteristic information of the lighting member And a rendering process based on the lighting member position information, and a step of displaying the object as a two-dimensional image on the screen based on the image data obtained by the rendering process. A computer graphics reproducing method is provided.

  In the computer graphics reproduction method of the present invention, it is preferable that the optical characteristic of the lighting member is represented by a bidirectional reflectance distribution function or a transmittance distribution function.

  Furthermore, a third aspect of the present invention is a computer graphics program for creating image data for displaying a three-dimensional image of an object created in a virtual three-dimensional coordinate space as a two-dimensional image on the screen of a display device. A procedure for causing a computer graphic system including the display device and a computer to perform modeling processing of the object based on shape information of the input object, and model data of the object obtained by the modeling processing; Position information of the object in the virtual three-dimensional coordinate space, surface information of the object, light source information set and inputted, lighting member information of a lighting member for adjusting light incident on the object, information on optical characteristics of the lighting member And based on positional information of the lighting member in the virtual three-dimensional coordinate space. And providing a computer graphics program for executing a procedure for performing a rendering process and a procedure for displaying the object as a two-dimensional image on the screen based on the image data obtained by the rendering process. It is.

In the computer graphics program of the present invention, it is preferable that the light source information includes form information of the light source and arrangement position information indicating a position of the light source arranged in the virtual three-dimensional coordinate space.
Moreover, it is preferable that the optical characteristic of the lighting member is represented by a bidirectional reflectance distribution function or a transmittance distribution function.

  According to the computer graphics system of the present invention, the lighting member information of the lighting member that adjusts the light incident on the object arranged in the virtual three-dimensional coordinate space and the optical characteristic information of the optical characteristic of the lighting member are obtained. Image data of an object to be displayed as a two-dimensional image on a screen of a display device by providing at least one registered database unit as a set, arranging a light source and a lighting member at a predetermined position in a virtual three-dimensional coordinate space Can be generated by the calculation unit. As a result, a CG image can be created by reproducing the same lighting as in a photo studio, and an image with a high texture can be obtained. Furthermore, since the lighting member is simply arranged at a predetermined position in the virtual three-dimensional coordinate space, an image with a high texture can be easily obtained.

  Further, according to the computer graphics reproduction method and program of the present invention, the object modeling process based on the set object shape information, the object model data, the light source information obtained by the modeling process, Rendering process based on information of lighting member and information of optical characteristics thereof, and a process of displaying the object as a two-dimensional image on a screen based on image data obtained by the rendering process Thus, it is possible to reproduce a lighting similar to that of a photo studio and create a CG image. For this reason, an image with a high texture can be obtained. Furthermore, since only the arrangement position of the lighting member in the virtual three-dimensional coordinate space is set, an image with a high texture can be easily obtained.

Hereinafter, a computer graphics system, a computer graphics reproduction method, and a program according to the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
FIG. 1 is a block diagram illustrating a computer graphics system according to an embodiment of the present invention.

  As shown in FIG. 1, a computer graphics system (hereinafter also referred to as a CG system) 10 includes a database unit 12, an input unit 14, a control unit 16, and a monitor (display device) 18.

The CG system 10 of this embodiment includes at least a diffuse transmission plate that diffuses light incident on an object and a reflection plate that reflects light and enters the object in a virtual three-dimensional coordinate space (hereinafter also referred to as virtual space). One of them can be set. These diffuse transmission plates and reflection plates have optical characteristics set in advance. Thereby, by setting the diffuse transmission plate or the reflection plate in the virtual space, for example, lighting of a photo studio can be reproduced, and an image with excellent texture description as obtained in a commercial photograph is obtained as a CG image. It is something that can be done. Further, the CG system 10 according to the present embodiment can determine whether or not the lighting is appropriate for the object.
The CG system 10 of this embodiment basically has the same configuration as that of a general CG system 10, and stores information on the diffuse transmission plate and information on the reflection plate in combination with the optical characteristics thereof. The difference is that the database unit 12 is provided.

  In the database unit 12, lighting member information of a lighting member is registered in combination with light source form information of a light source and optical characteristics.

First, the light source form information of the light source will be described. The light source form information of the light source includes the form of the light source and the optical characteristics in the form of the light source. In the present invention, the light source information includes light source form information and the position of the light source in the virtual space.
The form of the light source is, for example, a spotlight or a fluorescent lamp.
In addition, the optical characteristics in the form of the light source are those represented by, for example, a bidirectional reflection distribution function (hereinafter referred to as BRDF (Bidirectional Reflection Distribution Function)) for a spotlight or a fluorescent lamp.

Here, FIG. 2 is a schematic diagram showing an optical model of a spotlight.
As shown in FIG. 2, in this embodiment, the spotlight 30 is an optical model having a point light source 32 and a reflecting plate 34 surrounding the point light source 32.
Using this optical model, based on the spectral wavelength of the point light source 32 and its intensity, the light reflected by the reflecting plate 34 and emitted to the outside is represented by BRDF, which is used as the optical characteristics of the spotlight 30. In the present embodiment, as the spotlight, for example, the spectral wavelength of the point light source 32 and its intensity, and the shape and reflectance of the reflector 34 are variously changed in the database unit 12 as the light source form. Multiple registered.

Further, the fluorescent lamp is modeled in the same manner as the spotlight, and the light emitted to the outside is represented by BRDF, which is the optical characteristic of the fluorescent lamp. In this case, the point light source 32 of the spotlight shown in FIG. 2 is a line light source, and the number thereof is one or plural. However, the configuration of the other models is the same as that shown in FIG.
In the present embodiment, the number of the linear light sources, the arrangement of the linear light sources, the spectral wavelength of the linear light source, and its intensity, and the shape and the reflectance of the reflector are variously changed for the fluorescent lamp. A plurality of forms are registered in the database unit 12.
A known light source model can be used for the point light source, the line light source, and the surface light source, and these point light source, line light source, and surface light source are also variously registered in the database unit 12.

  In this embodiment, the light source can be selected from a spotlight or a fluorescent lamp having the same name as the equipment actually used in the photo studio, and the brightness can also be selected by wattage. preferable. Moreover, it is preferable that the number of fluorescent lamps can be selected. This makes it possible to easily select the light source in the same way as selecting equipment in a photo studio.

  Further, in the database unit 12, information on a reflecting plate that reflects light incident on an object and information on optical characteristics of the reflecting plate are registered as a set, and further diffused transmission that diffuses light incident on the object. The information on the plate and the optical characteristic information on the diffuse transmission plate are registered as a set. In the present invention, the diffuse transmission plate and the reflection plate are collectively referred to as a lighting member. As described above, the writing member information of this writing member is registered in the database unit 12.

In this embodiment, the optical characteristics of the reflector are defined by the model shown in FIG.
Here, FIG. 3 is a schematic diagram for explaining optical characteristics of the reflector.
As shown in FIG. 3, when incident light Ii is incident on the surface 36a of the reflecting plate 36 at an incident angle α, it is reflected by the surface 36a and becomes reflected light Ir.
The reflected light Ir depends on the incident angle α, the roughness characteristics of the surface of the reflecting plate 36, and the wavelength of the incident light Ii. The reflected light Ir becomes specular reflection light Is or diffuse reflection light Id depending on the incident angle α. The distribution of the specular reflection light Is and the diffuse reflection light Id varies depending on the material of the reflection plate 36.
The BRDF can be obtained by measuring the reflected light Ir when the incident angle α of the incident light Ii is changed. This BRDF is used as the optical characteristic of the reflecting plate 36.

  For this reason, in the present embodiment, BRDF is registered in the database unit 12 for each material of the reflection plate 36. In this embodiment, for example, the optical characteristics are registered in the database unit 12 according to the names of the reflectors such as silver reflector, mirror reflector, white Kent paper, and black decora (trademark) plate. Various shapes and sizes of reflectors are also registered in the database unit 12. Thereby, in a present Example, the kind, shape, and magnitude | size of a reflecting plate can be selected.

Further, in this embodiment, the transmission characteristics of the diffuse transmission plate are represented by, for example, a transmittance distribution function, and are defined by the model of the diffuse transmission plate shown in FIG.
Here, FIG. 4 is a schematic diagram for explaining optical characteristics of the diffuse transmission plate.
As shown in FIG. 4, when the incident light Ii is incident on the surface 38a of the diffuse transmission plate 38 at an incident angle α, the incident light Ii passes through the diffusion transmission plate 38 and becomes transmitted light It.
The transmitted light It depends on the incident angle α, the transmission characteristics of the diffuse transmission plate 38, the surface roughness characteristics of the diffusion transmission plate 38, and the wavelength of the incident light Ii. The transmitted light It becomes the regular transmitted light Ist or the diffused transmitted light Idt depending on the incident angle α. The distributions of the regular transmitted light Ist and the diffuse reflected light Idt vary depending on the material of the diffuse transmission plate 38.
The transmitted light It is measured when the incident angle α of the incident light Ii is changed, and a transmittance distribution function is obtained. This transmittance distribution function is used as the optical characteristics of the diffuse transmission plate 38.

Therefore, in this embodiment, a transmittance distribution function is registered in the database unit 12 for each material of the diffuse transmission plate 38. In this embodiment, the optical characteristics of the diffusion transmission plate such as tracing paper, milky white acrylic plate, and white Kent paper are registered in the database unit 12. The diffuse transmission plate is also registered in the database unit 12 in various shapes and sizes.
Note that the curvature of the diffuse transmission plate (the degree of warpage of the diffuse transmission plate) is also registered in the database unit 12. In this case, it is preferable to register a transmittance distribution function in accordance with the curvature. However, the transmittance distribution function may be calculated by calculation according to the curvature. Thereby, in a present Example, the kind of diffuse transmission board, a shape, a magnitude | size, and its curvature can be selected.

FIG. 5 is a schematic diagram showing the form of the light source and the types of the diffuse transmission plate and the reflection plate stored in the database unit of this embodiment.
As shown in FIG. 5, in the database unit 12 of the present embodiment, the light source can be selected from, for example, a spotlight or a fluorescent lamp. The diffusion transmission plate can be selected from, for example, tracing paper, milky white acrylic plate, or white Kent paper. Further, the reflecting plate can be selected from, for example, silver reflex, mirror reflex, white Kent paper, or black decora (trademark) plate. The names of these light sources, diffuse transmission plates, and reflection plates are generally known names for those who take commercial photographs. The optical characteristics described above are registered in the database unit 12 in association with each.

  The input means 14 is input by the user with the shape information of the object expressed as CG, the surface information of the object, the position information of the object, the light source information and the viewpoint information, and the types of the reflection plate and the diffuse transmission plate and their arrangement positions For example, a mouse and a keyboard. The input means 14 is not particularly limited, and may be a tablet.

Further, as shown in FIGS. 6A and 6B, the input unit 14 uses a GUI (Graphical User Interface) to provide a light source necessary for lighting registered in the database unit in a hierarchical structure as shown in FIG. , Diffuse transmission plate, and reflection plate can be selected.
In the present embodiment, a lighting window 40 (input unit) is displayed on the screen of the monitor 18 as shown in FIG. The window 40 is provided with a title bar 42 indicating that the lighting is to be set, and further includes a “setting” button 44 for confirming the setting, and further, a “spot” indicating the form of the light source. A “light” button 46 a and a “fluorescent lamp” button 46 b are provided. Further, a “diffuse transmission plate” button 48 a and a “reflection plate” button 48 b are provided.

  In this embodiment, for example, when a “diffuse transmission plate” button 48a shown in FIG. 6A is clicked, a window 50 shown in FIG. 6B is displayed on the screen. This window 50 sets the type, shape and size of the diffuse transmission plate. The window 50 is provided with a title bar 52 indicating that a diffuse transmission plate is to be set, and a “tracing paper” button 54a and a “milky acrylic plate” are set for further setting the type. A button 54b and a “white Kent paper” button 54c are provided. Further, in order to set the shape, a “square” button 56a and a “circle” button 56b are provided. Further, an input field 58 for setting the size is provided, and entry fields 58a and 58b for width and height are provided. An input field 59 for inputting a curvature is also provided. For example, by inputting a positive number or a negative number in the input field 59, the direction of warping is changed, and when “0” is input, it is flat.

  Further, in this embodiment, by inputting numerical values in the entry fields 58a and 58b and the input field 59, the type, shape, size and curvature (curvature) of the diffuse transmission plate are set.

  In this embodiment, the diffuse transmission plate is described as an example, but the setting screen is displayed for the light source and the reflection plate as well as the diffusion transmission plate. For the light source, the form and brightness of the light source can be set, and for the reflector, the type, shape and size can be set.

The control unit 16 controls the database unit 12, the input unit 14, and the monitor 18, and further includes a calculation unit 20.
The control unit 16 includes surface information of the object input by the input unit 14 related to the object formed in the virtual space of the screen of the monitor 18, position information of the object in the virtual space, light source information and viewpoint information, and a reflector. And a virtual space (X axis, Y axis, and Z axis) in a virtual three-dimensional orthogonal coordinate system (X axis, Y axis, and Z axis) in the screen of the monitor 18, as shown in FIG. A virtual three-dimensional coordinate space) 60 is arranged and displayed as a two-dimensional image on the screen.

The object shape information is data that causes the monitor 18 to display an object having a three-dimensional shape.
The surface information of an object is information indicating surface characteristics, and examples thereof include surface roughness, surface material, surface specular reflectance, and surface diffuse reflectance.
The position information of the object is the position information of the object 62 in the virtual space 60 as shown in FIG. 7, and in the present embodiment, is represented by the coordinates on the X axis, the Y axis, and the Z axis. .

The light source information is the light source configuration information and the light source arrangement position in the virtual space 60 as described above. In the case of the light source L shown in FIG. 7, the arrangement position of the light source L is represented by the coordinates of the X axis, the Y axis, and the Z axis.
The viewpoint information is a camera position, a shooting direction, and a magnification at which the object 62 is shot by the camera in the virtual space 60. In this embodiment, the viewpoint information is, for example, a point represented by a viewpoint v and a photographing magnification of the object 62 at the viewpoint v as shown in FIG. This viewpoint v is also expressed by the coordinates of the X, Y, and Z axes.
Further, the arrangement position of the reflection plate or the diffuse transmission plate is also the arrangement position in the virtual space 60, and the arrangement position is represented by coordinates on the X axis, the Y axis, and the Z axis.

  The computing unit 20 provided in the control unit 16 is provided with a storage unit 22. As will be described later, the storage unit 22 stores the surface information of the three-dimensional object displayed as a two-dimensional image on the screen, the position information of the object, the light source information and the viewpoint information, and the types of the reflecting plate and the diffusing and transmitting plate. Is stored.

  The computing unit 20 performs modeling processing based on the shape information of the object, and obtains model data of the object that can be displayed on the screen of the monitor 18. The model representation by this modeling process is not particularly limited, and examples thereof include a polyhedron model, a wire frame model, a surface model, a solid model, and a metaball (shading function model).

Object model data obtained by this modeling process, optical characteristics and position in the form of the light source, surface information of the object, viewpoint information (camera shooting direction), arrangement position of the reflector or diffuse transmission plate, optical characteristics Based on the above, the rendering process is performed.
This rendering processing is processing for displaying model data (three-dimensional image data) on the screen of the monitor 18 as a two-dimensional image. In this embodiment, for example, a ray tracing method is used. In the present invention, the rendering process is not particularly limited, and various known processes can be used.

In this way, finally, image data of a two-dimensional image of the object viewed from the shooting direction shot by the camera is obtained.
For example, the image data is stored in the storage unit 22 and is output to the monitor 18 and displayed as a two-dimensional image.

  The monitor 18 is not particularly limited as long as it has a function of displaying the two-dimensional image data created by the calculation unit 20 as an image. Examples of the monitor 18 include a CRT, LCD, PDP, and organic EL display.

In the present embodiment, the light source and the lighting member are selected by the user and their arrangement positions in the virtual space are input by the input means. However, the light source, the lighting member, and their virtual space that are frequently used are used. The information on the arrangement position at may be registered in advance in the database unit 12 (see FIG. 1).
Further, the light source and the lighting member set by the user and the information on the arrangement position in the virtual space may be registered in the database unit 12 with, for example, a studio name.
Here, FIG. 8 is a schematic diagram showing an input unit for selecting a studio name registered in the database unit of the present embodiment.
As shown in FIG. 8, a window (input unit) 70 is provided with a title bar 72 indicating that a studio is to be selected. Further, an “OK” button 74 for confirming the setting is provided on the window 70. A “cancel” button 76 for canceling the setting is provided.
Further, the window 70 is provided with a list section 78 in which a predetermined number of studio names registered with a predetermined name are displayed. The list part 78 is provided with a scroll bar 78a. If the number of registered studio names is large and cannot be displayed in the list part 78, the studio registered in the database part 12 by the scroll bar 78a. You can see all of the names.

  In the present embodiment, for example, the item “for bottle” shown in the list part 78 of FIG. 8 is selected, and then the “OK” button 74 is clicked to register it in the database part 12 (see FIG. 1). On the basis of the set data for “bottle”, the control unit 16 (see FIG. 1) causes the registered light source and the registered lighting member (diffuser plate and / or reflector) to be predetermined in the virtual space. It is arranged at the position. For this reason, the user can omit the selection of the light source and the lighting member and the placement work in the virtual space by selecting a desired studio name from the list of studio names. In particular, when there are a plurality of light sources and lighting members and the selection work and the placement work are complicated, it is effective for labor saving.

Next, the computer graphics reproduction method of the present invention will be described. The program of the present invention is a program that causes a computer graphics reproduction method described in detail below to be executed on a computer or a computer graphics system.
FIG. 9 shows a flowchart of the computer graphics reproduction method of this embodiment. As an example, a case where the computer graphics reproduction method is operated on the computer graphics system (CG system) 10 shown in FIG. 1 will be described.

  First, an object to be reproduced is set according to a computer graphics reproduction method (S1). In the object setting S1, shape information of the object, surface information of the object, and position information of the object are input from the input unit 14 of the CG system 10 shown in FIG. 1, and information on these objects (hereinafter referred to as object information). Is stored in the storage unit 12. As described above, the object shape information is data for displaying a three-dimensional object on the monitor 18, and is, for example, information on the size or shape of the object. Further, as described above, the surface information of the object is information indicating the characteristics of the surface of the object. For example, the surface roughness, the surface material, the specular reflectance of the surface, or the diffuse reflectance of the surface is used. Can do. The shape information and surface information of these objects can be registered in advance in the database unit 12 in association with the article, for example. Then, when an article is specified, the shape information and surface information are displayed on the monitor, and the user is instructed and selected from them. The selected shape information and surface information are stored in the storage unit 22. In setting the position information of the object, the coordinates of the X axis, the Y axis, and the Z axis in the virtual space are input from the input unit 14, and the position of the object in the three-dimensional virtual space is set in the storage unit 22. Further, the position information of the object may be set by displaying an article in the virtual space on the monitor 18 and moving the article by an input means such as a mouse in the virtual space.

  Next, a light source used for reproducing an object in the virtual space is set (S2). In the light source setting S <b> 2, the light source configuration information and the light source position information are input from the input unit 14, and information on the light sources (hereinafter referred to as light source information) is stored in the storage unit 22. As described above, the light source form information is information including information on the light source form and information on optical characteristics of the light source form. For example, the type of light source such as a spotlight and a fluorescent lamp, the shape of the light source, the number of light sources, the light quantity of the light source, and the like are input from the input unit 14 as the light source form information and stored in the storage unit 22. The information on the optical characteristics of the form of the light source is, for example, information used to express the optical characteristics of the light source with a bidirectional reflection distribution function (BRDF) or a transmittance distribution function.

  Subsequently, a lighting member used for reproducing an object in the virtual space is set (S3). In the writing member setting S <b> 3, information on the type of the writing member and the arrangement position of the writing member is input from the input unit 14 and stored in the storage unit 22. In the database unit 12 of the CG system 10, writing member information and optical characteristic information of the writing member are registered in association with each other. The control unit 16 can extract the optical characteristic information of the lighting member from the database unit 12 based on the type of the lighting member input from the input unit 14. As for the arrangement position of the lighting member, the coordinates of the X axis, the Y axis, and the Z axis in the virtual space are input from the input unit 14. Thereby, the position of the lighting member in the virtual space is specified.

  Next, modeling processing is executed based on the object set in the object setting (S4). The modeling process S4 is executed in the arithmetic unit 20 of the CG system 10 shown in FIG. Model data obtained by this modeling process is stored in the storage unit 22.

  Next, based on the light source information set in the light source setting S2, the lighting member arrangement position information set in the lighting member setting S3, the optical characteristic information of the lighting member, and the model data obtained by the modeling process S4. Rendering processing is executed (S5). This rendering process S5 is executed by the computing unit 20 in the same manner as the modeling process. The image data obtained by the rendering process S5 is stored in the storage unit 22 of the CG system 10 and is output to the monitor 18, and a two-dimensional image is displayed on the monitor 18. Thus, the two-dimensional image of the object reproduced on the monitor 18 is excellent in transparency, three-dimensionality, and glossiness, and has the same texture as commercial photographs.

Here, the content is processed in the order of the object setting S1, the light source setting S2, the lighting member setting S3, the modeling process S4, the rendering process S5, and the monitor display S6. If the object is set and the light source setting, lighting member setting, and modeling process are executed before the rendering process, the order of the object setting, light source setting, and lighting member setting is It may be executed with.
Also, in the virtual space, the viewpoint information for specifying the position of the camera that shoots the article, the shooting direction, the shooting magnification, etc. is set, and based on this viewpoint information, light source information, lighting information, and model data A rendering process may be executed.

Here, the computer graphics reproduction method of the present invention will be described more specifically. FIGS. 6A and 6B are schematic views showing the input procedure by the input means according to the embodiment of the present invention, and FIG. 10 shows the light source and the lighting member in the computer graphics reproduction method of the embodiment. It is a schematic diagram which shows the arrangement | positioning state in the virtual three-dimensional coordinate space of a cake.
In the present embodiment, as shown in FIG. 10 will be described with the lighting to increase express texture of the cake S ₁ as an example.

First, the shape of the cake S ₁ is being instruction input by the input means 14 (see FIG. 1). Then, the input unit 14, the mirror reflectivity of the cake position of S _1, and the cake S ₁ of the surface in the virtual space 100, and the diffuse reflectance of the surface is instruction input.

  Next, the spotlight 102a is selected as the first light source. At this time, for the spotlight 102a, for example, a spotlight having a brightness of 800 watts is selected. Then, the position of the spotlight 102a in the virtual space 100 is designated and input.

  Next, the spotlight 102b is selected as the second light source. At this time, for the spotlight 102b, for example, a spotlight having a brightness of 300 watts is selected. Then, the position of the spotlight 102b in the virtual space 100 is designated and input.

Next, a black decora (trademark) plate 104 is selected as the reflection plate. Then, a square is selected as the shape of the black decora (trademark) plate 104, and its size is also set. Further, setting the arrangement position in the virtual space 100 of the black Decola (TM) plate 104 under the cake _{S 1.}

Next, white Kent paper 106 is selected as the diffuse transmission plate. Then, a square is selected as the shape of the white Kent paper 106, and its size is also set. Further, setting the arrangement position in the virtual space 100 white Kent paper 106 between the spotlight 102a and cake _{S 1.}

Next, the tracing paper 108 is selected as the diffuse transmission plate. Then, a square is selected as the shape of the tracing paper 108, and its size is also set. Further, the arrangement position in the virtual space 100 of the tracing paper 108 on black Decola (TM) plate 104, and is set between the spotlight 102b and cake _{S 1.}
Next, the camera shooting direction (not shown) is set.

Thus, as shown in FIG. 10, the cake S ₁ , the spotlights 102a and 102b (light source), the reflecting plate, and the diffusing and transmitting plate are arranged in a virtual space provided in the screen of the display unit. In this arrangement state, rendering processing in the shooting direction (viewpoint) of the camera is performed by, for example, the ray tracing method. By this rendering process, image data of a two-dimensional image that can be displayed on the screen of the monitor 18 (see FIG. 1) can be obtained.
Then, based on the image data, and displays the cake S ₁ as a two-dimensional image on the screen of the monitor 18.

In this embodiment, not only the cake S ₁ (object) and the light source, but also a diffuse transmission plate that diffuses light incident on the cake S ₁ from this light source, and reflection that reflects light incident on the cake S ₁ from the light source. The arrangement position of the board is set in the virtual space, and the shooting direction of the camera for shooting is set. These settings are Lighting texture cake S ₁ is higher, based on this setting state, since the rendering process, the texture of the cake S ₁ is, the CG which is reproduced equivalent to commercial photography An image can be obtained.

  In this embodiment, when a diffuse transmission plate or a reflection plate is selected, its optical characteristics are also determined simultaneously. For this reason, in this embodiment, the reflection plate or the diffuse transmission plate is represented by a name generally used in a photo studio, so that even a person without optical knowledge can use the reflection plate or the diffusion transmission plate. , You can choose as you would a normal photo studio. For this reason, the operation of the CG system 10 can be facilitated. Furthermore, lighting similar to that of a photographic studio can be easily reproduced in the virtual space without understanding the optical characteristics simply by disposing a reflecting plate or a diffuse transmitting plate at a predetermined position in the virtual three-dimensional coordinate space. As a result, the illumination effect required in commercial photography can be obtained, so that a CG image with excellent texture description can be easily obtained.

Next, another embodiment of the present invention will be described. The present embodiment will be described with an example of lighting that suitably expresses the texture of a metallic object.
FIG. 11 is a schematic diagram showing an arrangement state in a virtual three-dimensional coordinate space of a light source, a lighting member, and a knife in a computer graphics reproduction method according to another embodiment of the present invention. The program of the present invention is also a program for executing the computer graphics reproduction method of another embodiment of the present invention described in detail below.

  In this embodiment, each element arranged in the virtual space 110 is different from the above-described embodiment, and the selection method of each element is the same as in the above-described embodiment. Detailed description is omitted. Also in this embodiment, the above-described CG system 10 (see FIG. 1) can be used.

In the present embodiment, as shown in FIG. 11, in the virtual space 110, white Kent paper 112 is disposed under the knives S _2. The white Kent paper 112 is suspended, is warped to prevent shadows in the kitchen knife S _2.
Further, as the light source above the kitchen knife S _2, the spotlight 116 is disposed. For this spotlight 106, for example, one having a brightness of 1200 watts is selected. Tracing paper 114 is provided between the spotlight 116 and knife S _2. The tracing paper 114 is warped so as to protrude kitchen knife S ₂ side. Further, on the side of the blade of the kitchen knife S ₂ is silver reflex 118 is disposed.

In the present embodiment, the knives S _{2 (the} object), and not only a light source, for reflecting the light incident tracing paper to diffuse light incident from the light source to the kitchen knife S _2, and from the light source to the kitchen knife S ₂ The arrangement positions of the silver reflex and white Kent paper are set in the virtual space, and further, the shooting position of the camera for shooting is set. This setting state is for texture kitchen knife S ₂ can be suitably expressed, on the basis of the setting state, since the rendering process, comparable texture metallic which was Kiratsu kitchen knife S ₂ and a commercial photography It is possible to obtain a CG image reproduced in the above.

  The present invention is basically as described above. The computer graphics system, computer graphics reproduction method, and program of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various improvements or modifications can be made without departing from the spirit of the present invention. Of course, changes may be made.

  In any of the above-described embodiments, the lighting member used in the studio for taking commercial photographs can be arranged in the virtual space for rendering processing, so that the lighting effect can be easily determined. it can.

  In addition, lighting effects can be determined by simply placing them in a virtual space as if the lighting members were set in the studio, so even a person with no special knowledge about optics can easily create CG images with a high texture description. Can get to.

  Furthermore, in the present invention, for example, a plurality of studios in which lighting is set in accordance with the characteristics of an object such as a metallic texture, a food texture, or a glass texture are registered in the database unit 12, for example. In addition, the user can select the studio according to the texture of the CG object to be expressed (see FIG. 8). Thereby, even a person who has no further knowledge of optics can obtain a CG image with a high texture description even more easily.

  The present invention is also suitable for a simulation for confirming the lighting effect of a photo studio. As a result, the lighting effect can be confirmed before installing the equipment in the actual photo studio.

  In the present invention, it is only necessary that necessary data is input by an input unit or the like when performing modeling processing and rendering processing. For this reason, the input order of each data is not specifically limited. For example, after all the data has been input, the modeling process and the rendering process may be performed. Further, after the modeling process, the rendering process may be performed after waiting for input of data necessary for the rendering process. Also good.

1 is a block diagram illustrating a computer graphics system according to an embodiment of the present invention. It is a schematic diagram which shows the optical model of a spotlight. It is a schematic diagram explaining the optical characteristic of a reflecting plate. It is a schematic diagram explaining the optical characteristic of a diffuse transmission board. It is a schematic diagram which shows the form of the light source memorize | stored in the database part of a present Example, and the kind of a diffuse diffusion transmission board and a reflecting plate. (A) And (b) is a schematic diagram which shows an example of the input means of the computer graphics system of a present Example. It is a schematic diagram which shows the virtual three-dimensional coordinate space in the computer graphics system of a present Example. It is a schematic diagram which shows the input part for selecting the studio name registered into the database part of a present Example. It is a flowchart of the computer graphics reproduction method of a present Example. It is a schematic diagram which shows the arrangement | positioning state in the virtual three-dimensional coordinate space of the light source in the computer graphics reproduction method of a present Example, a lighting member, and a cake. It is a schematic diagram which shows the arrangement | positioning state in the virtual three-dimensional coordinate space of the light source in the computer graphics reproduction method of the other Example of this invention, a lighting member, and a kitchen knife.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Computer graphics system 12 Database part 14 Input means 16 Control part 18 Monitor 20 Calculation part 22 Memory | storage part 30,102a, 102b, 116 Spotlight 36 Reflector 38 Diffuse transmission plate 40, 50, 70 Window 60, 100, 110 Virtual 3D coordinate space (virtual space)
62 Object 104 Black Decora (trademark) board 106, 112 White Kent paper 108, 114 Tracing paper 118 Silver reflex L Light source v View point

Claims (10)

A computer graphics system for displaying a three-dimensional image of an object created in a virtual three-dimensional coordinate space as a two-dimensional image of the object on a screen of a display device,
Lighting member information of a lighting member that adjusts light incident on the object arranged in the virtual three-dimensional coordinate space, and at least one optical property information related to optical characteristics of the lighting member are registered and registered. The database department
Shape information of the object created in the virtual three-dimensional coordinate space, surface information of the object, position information of the object in the virtual three-dimensional coordinate space, light source of a light source provided in the virtual three-dimensional coordinate space Information, viewpoint information to be displayed as the two-dimensional image, and input means for instructing and inputting the type of the lighting member and arrangement position information in the virtual three-dimensional coordinate space;
Based on the shape information of the object, the surface information of the object, the position information of the object, the light source information, the viewpoint information, the lighting member information, the optical characteristic information of the lighting member, and the arrangement position information of the lighting member, A computer graphics system comprising: an arithmetic unit that generates image data of the object displayed as a two-dimensional image on the screen.   The input unit further includes an input unit for instructing and inputting at least one of light source information and the lighting member information provided in the virtual three-dimensional coordinate space, and the input unit is displayed on a screen of the display device. 2. The computer graphics system according to claim 1, wherein an instruction is input.   The computer graphics system according to claim 1, wherein the writing member is a diffuse transmission plate or a reflection plate.   The computer graphics system according to claim 1, wherein the optical characteristic of the lighting member is represented by a bidirectional reflectance distribution function or a transmittance distribution function.   The computer graphics system according to any one of claims 1 to 4, wherein the light source information includes information on a form of the light source and position information in the virtual three-dimensional coordinate space. A computer graphics reproduction method for displaying a three-dimensional image of an object created in a virtual three-dimensional coordinate space as a two-dimensional image of the object on a screen of a display device,
Setting object shape information, object surface information, and position information of the object in the virtual three-dimensional coordinate space;
Setting light source information including form information of a light source provided in the virtual three-dimensional coordinate space and arrangement position information indicating an arrangement position of the light source in the virtual three-dimensional coordinate space;
Setting of lighting member information of a lighting member that adjusts light incident on the object, optical characteristic information regarding optical characteristics of the lighting member, and lighting member position information indicating an arrangement position of the lighting member in the virtual three-dimensional coordinate space And a process of
A process of modeling the object based on the set shape information of the object;
A rendering process based on the model data of the object obtained by the modeling process, the light source information, the lighting member information, the optical characteristic information of the lighting member, and the lighting member position information;
And displaying the object as a two-dimensional image on the screen based on the image data obtained by the rendering process.   The computer graphics reproduction method according to claim 6, wherein the optical characteristic of the lighting member is represented by a bidirectional reflectance distribution function or a transmittance distribution function. A computer graphics program for creating image data for displaying a three-dimensional image of an object created in a virtual three-dimensional coordinate space as a two-dimensional image on a screen of a display device,
In a computer graphic system including the display device and a computer,
A procedure for performing modeling processing of the object based on the shape information of the input object;
Model data of the object obtained by the modeling process, position information of the object in the virtual three-dimensional coordinate space, surface information of the object, light source information set and input, and a lighting member that adjusts light incident on the object A rendering process based on the lighting member information, the optical property information of the lighting member, and the position information of the lighting member in the virtual three-dimensional coordinate space;
A computer graphics program for executing a procedure for displaying the object as a two-dimensional image on the screen based on image data obtained by the rendering process.   The computer graphics program according to claim 8, wherein the light source information includes form information of the light source and arrangement position information indicating a position of the light source arranged in the virtual three-dimensional coordinate space.   The computer graphics program according to claim 9, wherein the optical characteristic of the lighting member is represented by a bidirectional reflectance distribution function or a transmittance distribution function.

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