JP4839760B2 - Image generation device, image generation method, etc. - Google Patents

Description

The present invention relates to a technical field such as an image generation apparatus and an image generation method for generating a two-dimensional image of an object based on shape data of the object in a virtual space.

  Conventionally, when a two-dimensional image is generated by shading (shading) an object in a virtual space by computer graphics, the operator sets light source data, and the image generation apparatus 2 sets the light source data based on this setting. Generate a dimensional image and display it on the screen. After that, the operator adjusts parameters such as the position, angle, and light intensity of the light source and parameters such as the color and material of the object while observing the result displayed on the screen, so that the operator approaches the image having the shading intended by the operator. The way to go is taken.

  However, such a method indirectly specifies a shadow to be applied to a two-dimensional image by adjusting parameters of a light source, an object, etc., so that it approaches an intended image while repeating trial and error. This requires a lot of work, which increases the burden on the operator and makes it difficult to generate an intended image.

  To solve this problem, for example, in the computer graphics system described in Patent Document 1, the operator sets the highlight position, brightness, etc., for which the brightness is to be maximized for the two-dimensional image displayed on the screen. Then, the position of the light source is set by calculating the shading equation in reverse. Then, a new two-dimensional image of the object is generated using the light source data thus changed.

According to this method, a two-dimensional image in which the brightness at the designated highlight position is maximized can be generated.
Japanese Patent Laid-Open No. 7-129795

  However, although the method of Patent Document 1 described above can reduce the operator's workload because it can specify the highlight distribution center position on the object, what kind of shading is applied to the two-dimensional image by the highlight reflection effect. (For example, the size of the highlight, the range, the shade of the color, the degree of blurring of the outline, etc.) is a situation that cannot be understood unless you actually try it. Eventually, the image that the operator intended while repeating trial and error There is a problem that it is necessary to work closer to the object.

The present invention has been made in view of the above, the object in the virtual space, the image generating device makes it possible to easily generate a two-dimensional image shading intended by has been subjected, the image generation The purpose is to provide a method and the like.

In order to solve the above-described problem, the invention described in claim 1 is an image generation apparatus that generates a two-dimensional image of an object based on shape data of the object in a virtual space, and displays the two-dimensional image. and display means for, highlight expression adding means for adding highlighting representation for any region of the displayed two-dimensional image, corresponding to the area highlighted representation is added by the highlight expressing adding means A light source generating means for generating, in the virtual space, a surface light source having a light intensity distribution such that an illuminance distribution of highlight in a region of the surface of the object becomes an illuminance distribution expressed by the added highlight expression ; And a two-dimensional image generating means for generating a new two-dimensional image of the object using the generated surface light source.

According to a second aspect of the present invention, in the image generating apparatus according to the first aspect , the illuminance distribution of the highlight expression added by the highlight expression adding means is obtained, and the surface light source generated by the light source generating means is The light source is located in the regular reflection direction from the line-of-sight direction with respect to the object surface, and has a light intensity distribution according to the obtained illuminance distribution.

The invention according to claim 3 is an image generation method in an image generation apparatus that generates a two-dimensional image of an object based on shape data of the object in a virtual space, wherein the display control means included in the image generation apparatus includes A display step of displaying the two-dimensional image on a display unit, and a highlight expression adding unit included in the image generation device, in an arbitrary region of the displayed two-dimensional image based on an instruction input from the input unit A highlight expression adding step for adding a highlight expression to the area, and a light source generating means included in the image generation apparatus includes a region on the surface of the object corresponding to the area to which the highlight expression is added in the highlight expression adding step. A surface light source having a light intensity distribution such that the illuminance distribution of the highlight is an illuminance distribution expressed by the added highlight expression, A light source generating step of generating the virtual space, the two-dimensional image generating means for said image generating device comprises, using the generated surface light source, a two-dimensional image generating step of generating a new two-dimensional image of the object , Including.

According to a fourth aspect of the present invention, a computer is caused to function as the image generation apparatus according to the first or second aspect.

According to the present invention, with respect to two-dimensional images of the displayed object, for example, the size of the highlight range, shades of color, the highlight expression, such as blurring degree of the contour is added, is the additional A surface light source having a light intensity distribution that generates a two-dimensional image having a highlight is generated, and an object highlighted using the surface light source in accordance with a highlight expression added to the two-dimensional image Therefore, it is possible to easily generate a two-dimensional image having a highlight as intended.

  Hereinafter, the best embodiment of the present invention will be described in detail with reference to the drawings. The embodiment described below is an embodiment when the present invention is applied to a highlight image generation apparatus that generates a highlighted two-dimensional image of an object in a virtual space and displays it on a screen. It is.

[1] Outline of Configuration and Function of Highlight Image Generation Device S First, the configuration and function of the highlight image generation device S according to the present embodiment will be described.

  FIG. 1 is a block diagram illustrating an example of a schematic configuration of a highlight image generation apparatus S according to the present embodiment.

  As shown in FIG. 1, the highlight image generation apparatus includes a control unit 1 including a CPU, a RAM, a ROM, etc., various programs (for example, an image generation processing program) and data (light source data, shape / material data, etc.). Storage unit 2 (for example, hard disk drive, floppy (registered trademark) disk drive, optical disk drive, etc.), and input instruction unit 3 (for example, keyboard, mouse, light pen, etc.) as shadow expression adding means, And an image display unit 4 (for example, a display) as display means.

  As the highlight image generation apparatus S, for example, a personal computer, a workstation, a PDA (Personal Digital Assistant), or the like is applicable.

The control unit 1 reads and executes various programs stored in the ROM or the storage unit 2 by the CPU, thereby performing overall control of the highlight image generation device S, and the light source generation unit and the two-dimensional image according to the present embodiment. and functions as generating means or the like.

The control unit 1 functionally includes the shape, material data holding unit 11, a viewpoint data storage unit 12, a light source data storage unit 13, the highlight data holding unit 14, the highlight of a light source generating means The generation unit 15 and an image generation unit 16 as a two-dimensional image generation unit are configured.

  The shape / material data holding unit 11 stores object shape data (for example, vertex position, line segment data, surface data, etc.) and material data (for example, reflectance) read from the storage unit 2. The

  The viewpoint data holding unit 12 stores, for example, data such as a viewpoint position, a line-of-sight direction, and a viewing angle.

  The light source data holding unit 13 stores data such as the type, position, and light intensity of the light source read from the storage unit 2. The light source data holding unit 13 stores data such as the light intensity distribution of the highlight light source.

  The highlight light source generated by the highlight generation unit 15 is a surface light source having a certain spread, and has independent light intensity (luminance of the light source) at each position in the region. Accordingly, the entire light source region has a certain light intensity distribution, and the data has, for example, a structure in which a light intensity map associated with a position in the light source region is configured for each color of RGB. ing.

  The highlight data holding unit 14 stores the highlight distribution (illuminance distribution according to the present embodiment) of the highlight area generated on the object surface by the highlight generation unit 15.

  The highlight distribution is a distribution based on a collection of illuminance (brightness of the portion illuminated by the light source) at each position in the area illuminated by the highlight light on the object surface in the virtual space. The illuminance map associated with the position in the region illuminated by the highlight light has a structure configured for each color of RGB.

  The highlight generation unit 15 converts the highlight distribution of the highlight expression added to an arbitrary area of the two-dimensional image of the object displayed on the image display unit 4 by the input instructing unit 3 to the object in the virtual space. A coordinate distribution is converted to the surface to generate a highlight distribution on the surface of the object. A specific method will be described below.

  In order to convert a two-dimensional image of an object in the three-dimensional virtual space onto a view window (an area displayed on the image display unit 4 on the projection plane), for example, by projective transformation, the world coordinates of the object (in the virtual space) Coordinates) to window coordinates (coordinates in the view window). Specifically, the window coordinates are obtained by multiplying a predetermined projective transformation matrix and the world coordinates of the object.

The highlight generation unit 15 calculates the highlight distribution on the object surface from the highlight distribution of the region where the highlight expression is added on the view window, and stores this in the highlight data holding unit 14.

The highlight generation unit 15 reflects the highlight distribution on the object surface on the environment object in the virtual space to generate a highlight light source.

  This is performed based on the same idea as reflection mapping, which is one of the methods of reflecting other objects on the object surface by specular reflection. The specific method will be described below.

  FIG. 2 is a diagram illustrating an example of how a highlight light source is generated.

As shown in FIG. 2, the range in which highlight the object surface are distributed as S, the illuminance of the reflected light at the position x that within that range as Pc (x) (Pc (x ) is Ha in the object surface Equal to the illuminance at position x of the illite distribution).

  First, the line-of-sight direction V toward the position x on the object surface is obtained from the viewpoint. Next, a regular reflection direction R from the line-of-sight direction V with respect to the position x on the object surface is obtained. Then, a position θ where the regular reflection direction R from the position x intersects the environmental object plane is obtained. If a possible range of the position θ with respect to the range S is ω, a highlight light source having ω as the range is generated.

  The light intensity Pr (θ) of the highlight light source at the position θ can be obtained by the following equation.

式１において、ｋはハイライト反射係数であり、予め光源データ保持部１３に記憶されている。

In Equation 1, k is a highlight reflection coefficient and is stored in the light source data holding unit 13 in advance.

  The highlight generation unit 15 obtains the light intensity for the entire range S (the entire range ω) and stores it in the light source data storage unit 13 as the light intensity distribution of the highlight light source.

  In this way, the highlight generation unit 15 is a highlight light source having a light intensity distribution that generates a two-dimensional image of an object having a highlight added to the two-dimensional image displayed on the image display unit 4. As a light source generating means for generating in a virtual space.

  The image generation unit 16 generates a new two-dimensional image of the object through rendering processing including projective transformation, clipping, hidden surface removal, shading, texture mapping, and the like based on the shape / material data, viewpoint data, light source data, and the like. Are displayed on the image display unit 4.

  In the shading process, the illuminance Pc (x) of the reflected light from the highlight light source with respect to the position x on the object surface is obtained by the following equation obtained by modifying Equation 1.

なお、その他の処理は公知であるので詳しい説明は省略する。

Since other processes are publicly known, detailed description is omitted.

  Next, an operation screen for adding highlight to an object will be described. FIG. 3 is a diagram illustrating an example of an operation screen according to the present embodiment.

  When the image generation program is started by the operation of the input instruction unit 3 by the operator, for example, an operation screen as shown in FIG. 3 is displayed on the image display unit 4.

  The operation screen includes an image display area 41 on which a two-dimensional image 411 of an object is displayed, a color selection menu 42 for selecting a highlight color, and a shape (size and outline blur) of a brush to which highlight is added. A brush selection menu 43 for selecting a condition, and an image generation button 44 for starting generation of a two-dimensional image.

  The operator selects a highlight color to be added to the two-dimensional image 411 from the color selection menu 42 using the input instruction unit 3, and selects a brush shape from the brush selection menu 43.

  Next, for example, when the operator moves the mouse so as to trace the area to be highlighted while pressing the mouse button at an arbitrary position on the two-dimensional image 411, the highlight expression 412 is displayed on the two-dimensional image 411. Is displayed.

  In this way, the input instruction unit 3 functions as a shadow expression adding unit that adds the highlight expression 412 to an arbitrary region of the two-dimensional image displayed on the image display unit 4. After that, another highlight color or another brush shape may be selected and a highlight expression 412 may be further added.

  When the highlight expression 412 intended by the operator is added in this way, the operator operates the input instruction unit 3 to select the image generation button 44, thereby generating a highlight light source and a two-dimensional image. Is started.

[2] Operation of Highlight Image Generating Device S Next, an operation example of the highlight image generating device S having the above configuration will be described.

  FIG. 4 is a diagram illustrating an example of a state from when a highlight expression is added to a two-dimensional image until a highlight light source is generated. FIG. 5 is a flowchart illustrating an example of a process flow of the highlight image generation apparatus S according to the present embodiment.

  As shown in FIG. 4, an object 101 is arranged in a virtual space, and an environmental object 102 is arranged so as to contain it (the environmental object according to the present embodiment is a sphere, but for example, a cube May be). Further, a view volume 103 for clipping processing is configured based on the viewpoint position, the viewing angle, and the like, and the near clip plane 103a and the far clip plane 103b for limiting the view volume 103 are two-dimensional images of the object 101. Are provided in parallel with the view window 104 on which the image is projected. Note that the view window 104 is originally conceptually located in the view volume 103, but in FIG. 4, it is shown outside the view volume 103 for explanation.

  When the highlight expression 412 is added to the two-dimensional image and the image generation button 44 is selected, as illustrated in FIG. 5, the highlight generation unit 15 displays the pixels on the area to which the highlight expression 412 is added. The window coordinates Pw in the view window 104 are converted into coordinates Ps on the near clip plane 103a (step S1). This conversion is obtained by the following equation, for example.

なお、式３において、Ｍｖはビューポート変換行列であり、この行列は、ビューウインドウと近クリップ面１０３ａとの縦の長さの比、横の長さの比により求めることができる。

In Equation 3, Mv is a viewport transformation matrix, and this matrix can be obtained by the ratio of the vertical length and the horizontal length of the view window and the near clip plane 103a.

  Next, the highlight generation unit 15 converts the coordinates Ps to world coordinates Pnv (step S2).

Then, the highlight generation unit 15 obtains the coordinates Pv of the position where the position of the viewpoint 105 (world coordinates Vv), the straight line direction V passing through Pnv, and the surface of the object 101 intersect (Step S3).

Then, the highlight generating unit 15, as illuminance at coordinates Pv of the surface of the object 101, stores the illuminance of the highlight color in the coordinates Pw on view window 104, the highlight data holding unit 14 in association with the coordinates Pv (Step S4).

  Thereafter, the highlight generation unit 15 determines whether or not processing has been performed for all the pixels on the region to which the highlight expression 412 is added (step S5), and if there is a pixel that has not been processed (step S5). : NO), the process of steps S1 to S4 is repeated for the remaining pixels.

When all the pixels are processed (step S5: YES), all the illuminances in the highlight area on the surface of the object 101 are stored in the highlight data holding unit 14, thereby The generation of the highlight distribution 106 is completed.

  Thereafter, the highlight generation unit 15 obtains the coordinates Lv of the light source on the environmental object 102 with respect to the highlight distribution 106 generated on the surface of the object 101 by the method described above (step S6), and coordinates on the surface of the object 101 The light intensity of the highlight light source corresponding to the illuminance of Pv is obtained by Equation 1 (step S7) and stored in the light source data holding unit 13 (step S8).

  Next, it is determined whether or not processing has been performed for all positions of the highlight distribution 106 (step S9). If there is a position that has not been processed (step S5: NO), the highlight generation unit 15 The processes in steps S6 to S8 are repeated for the position.

  When the processing is performed for all positions (step S9: YES), the light intensity distribution of the highlight light source 107 is stored in the light source data storage unit 13, the generation of the highlight light source 107 is completed, and the process proceeds to step S10. To do.

  In step S10, the image generation unit 16 reads shape / material data, viewpoint data, light source data of the highlight light source 107 generated by the highlight generation unit 15, and the like, and uses these data to create a new two-dimensional image. Is generated and displayed on the image display unit 4 (step S11).

  The highlight reflection effect of the two-dimensional image generated in this way is equivalent to the highlight expression added on the operation screen. That is, the highlight reflection effect intended by the operator can be directly specified.

  By the way, once the highlight light source is generated and the two-dimensional image of the object is generated, the viewpoint, the object, and the light source are changed by changing the position of the viewpoint, rotating the object, or moving the object. If the positional relationship changes, the highlight reflection effect changes, and the operator needs to work again to obtain the intended highlight.

  However, in this embodiment, even in such a case, the highlight when the two-dimensional image is first generated can be easily reproduced.

  That is, since the highlight data is stored in the highlight data storage unit 2 when the highlight light source is generated by the highlight generation unit 15, the state is the same as the state in which the process of step 5 in FIG. ing.

  Therefore, when the image generation button 44 is selected by the operation of the input instruction unit 3 by the operator, the highlight generation unit 15 starts processing from step S6, and the viewpoint position, the coordinates of the highlight area, and the brightness of the highlight color. A new highlight light source may be generated based on the normal direction in the highlight area of the object surface.

  When the object is rotated, moved, etc., the coordinates of the highlight area may be converted accordingly.

  As described above, according to the present embodiment, the input instruction unit 3 adds a highlight expression to an arbitrary region of the two-dimensional image of the object displayed on the image display unit 4, and the highlight generation unit 15 generates a highlight light source having a light intensity distribution in such a manner that a two-dimensional image having the added highlight is generated in the virtual space, and the image generation unit 16 uses the highlight light source to Therefore, it is possible to easily generate a two-dimensional image with a shade as intended.

Further, a highlight distribution of the highlight expression added by the input instruction unit 3 is obtained, and the highlight light source is located in the regular reflection direction from the line-of-sight direction with respect to the object surface, and according to the obtained highlight distribution. It is possible to generate a highlight light source with a simplified method such as reflection mapping and generate a two-dimensional image with a shade as intended. It becomes.

It is a block diagram which shows an example of schematic structure of the highlight image generation apparatus which concerns on this embodiment. It is a figure which shows an example of a mode that a highlight light source is produced | generated. It is a figure which shows an example of the operation screen which concerns on this embodiment. It is a figure which shows an example of a mode until a highlight light source is produced | generated from the area | region where highlight expression was added to the two-dimensional image. It is a flowchart which shows an example of the flow of a process of the highlight image generation apparatus S which concerns on this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control part 2 Memory | storage part 3 Input instruction | indication part 4 Image display part 11 Shape / material data holding part 12 Viewpoint data holding part 13 Light source data holding part 14 Highlight data holding part 15 Highlight generation part 16 Image generation part 41 Image display area 42 Color selection menu 43 Brush selection menu 44 Image generation button 101 Object 102 Environmental object 103 View volume 103a Near clip plane 103b Far clip plane 104 View window 105 View point 106 Highlight distribution 107 Highlight light source 411 Two-dimensional image of object 412 Highlight Representation S Highlight image generator

Claims (4)

An image generation device that generates a two-dimensional image of an object based on shape data of the object in a virtual space,
Display means for displaying the two-dimensional image;
Highlight expression adding means for adding a highlight expression to an arbitrary region of the displayed two-dimensional image;
Light such that the illuminance distribution of the highlight in the area of the surface of the object corresponding to the area to which the highlight expression is added by the highlight expression adding means becomes the illuminance distribution expressed by the added highlight expression. A light source generating means for generating a surface light source having an intensity distribution in the virtual space;
Two-dimensional image generation means for generating a new two-dimensional image of the object using the generated surface light source;
An image generation apparatus comprising: The image generation apparatus according to claim 1,
Find the illuminance distribution of the highlight expression added by the highlight expression adding means ,
Surface light source generated by the light source generating means is located in the specular reflection direction from the viewing direction relative to the object surface, the image generating apparatus characterized by having a light intensity distribution corresponding to the obtained illumination distribution. An image generation method in an image generation apparatus that generates a two-dimensional image of an object based on shape data of the object in a virtual space,
A display step in which the display control means provided in the image generation device displays the two-dimensional image on a display unit ;
A highlight expression adding unit included in the image generation apparatus adds a highlight expression to an arbitrary area of the displayed two-dimensional image based on an instruction input from an input unit ;
The light source generation means included in the image generation apparatus is configured such that the illuminance distribution of the highlight in the area of the surface of the object corresponding to the area to which the highlight expression is added in the highlight expression adding step is the added highlight expression. A light source generation step of generating a surface light source having a light intensity distribution in the virtual space so as to be an illuminance distribution expressed by:
A two-dimensional image generation step in which a two-dimensional image generation means included in the image generation device generates a new two-dimensional image of the object using the generated surface light source;
An image generation method comprising:   An image generation processing program for causing a computer to function as the image generation apparatus according to claim 1.

Images