JP5423276B2 - Image processing program and computer-readable recording medium - Google Patents

Description

  The present invention relates to a display image generation technique in a video game, a CG (Computer Graphics) video, or the like.

  In video games, CG videos, etc., there are often scenes that require raining images. Furthermore, there is a case where an expression called rain glare in which rain stripes around a light source shine by light emitted from a street lamp or the like in a night scene in addition to raining may be desired.

  In Patent Document 1, in order to suppress an increase in processing load caused by placing snow objects or the like in the entire three-dimensional game space when displaying a snow or rain state on a game screen, A technique for arranging a snow object or the like only in a limited area is disclosed.

  Patent Document 2 discloses a technique for expressing reflected light (glare) from a light source in an impactable form on an object such as a sword.

JP 2007-82859 A JP 2006-323514 A

  According to the technique disclosed in Patent Document 1 described above, it is possible to display a state in which snow and rain are falling with a small processing load. However, in the night scene, rain lines around the light source are caused by light emitted from street lamps and the like. It cannot express shining rain glare.

  The technique disclosed in Patent Document 2 expresses reflected light of a light source by an object such as a sword. When the technique disclosed in Patent Document 2 is applied to rain glare in which rain stripes around a light source shine by light emitted from a streetlight or the like, a number of complicated calculations for expressing reflected light are set in a three-dimensional game space. This must be done for every rain streak object, which increases the load of calculation processing.

  The present invention has been proposed in view of the above-described conventional problems, and the object of the present invention is to express rain glare in which rain stripes around a light source shine by light emitted from a streetlight or the like by simple processing. An image processing program and a computer-readable recording medium are provided.

  In order to solve the above problems, in the present invention, as described in claim 1, a computer is set with a virtual viewpoint for a virtual space in which an object including at least a self-luminous object is arranged, Coordinate transformation means for projecting an object arranged inside the viewing frustum with the virtual viewpoint as a reference onto a projection plane; passing object generation means for generating a passing object passing around the self-luminous object in the virtual space; Holding means for holding color information of the self-luminous object and depth information of the object in the virtual space for each pixel of the projection plane in a memory, neighborhood coordinate calculation means for calculating the neighborhood coordinates of the passing object on the projection plane The self-luminous object in the neighborhood coordinates calculated from the holding means. Color information acquisition means for acquiring the color information and depth information of the image, multiplying the color information and the depth information to acquire the influence color information, and color setting means for reflecting the acquired influence color information on the color of the passing object The gist of the image processing program is to function.

  In addition, as described in claim 2, in the image processing program according to claim 1, the color information acquisition unit is configured such that the color of the passing object decreases as the depth of the self-luminous object in the vicinity coordinates decreases. In this case, the color setting means can set the color of the passing object to be brighter as the depth of the passing object is smaller.

  According to a third aspect of the present invention, in the image processing program according to the second aspect, the passing object generating means randomly generates the passing object as a line polygon composed of a plurality of vertices. The color information acquisition unit obtains the influence color information by multiplying the color information of the neighboring coordinates and the luminance information for each vertex, and the color setting unit acquires the influence color information. Color information can be reflected in the color of each vertex of the passing object.

  According to a fourth aspect of the present invention, in the image processing program according to the third aspect, the computer is configured to set a positive value to a y-axis value with respect to the top vertex of the passing object. A vector of a negative value is set to the y-axis value for the bottom vertex, and the vector is set as a vector setting unit that continuously sets the vector between the vertices between them. Two vectors having a positive value for the axis and a negative value for the x-axis are added to the vectors set at the vertices of the passing object, and the color information acquisition means is configured to add the two additions. The influence color information can be acquired by adding the multiplication value of the color information and the depth information obtained from the coordinates on the projection plane corresponding to the vector.

  The image processing program according to claim 4, wherein the computer sets the y-axis value to +1 with respect to the top vertex of the passing object, and the bottom The y-axis value is set to −1 with respect to the vertices of the vector, and the vector is set as a vector setting means for continuously setting the vectors between the vertices between them. And two vectors whose x-axis values are −1 are added to vectors set at the vertices of the passing object, and the color information acquisition means is on the projection plane corresponding to the two added vectors. The influence color information can be acquired by adding the multiplication value of the color information and the depth information obtained from the coordinates.

  Further, as described in claim 6, it can be configured as a computer-readable recording medium for recording the image processing program according to any one of claims 1 to 5.

  With the image processing program and computer-readable recording medium of the present invention, it is possible to express rain glare in which rain stripes around the light source shine by light emitted from a streetlight or the like by simple processing.

It is a figure which shows the structural example of the image processing apparatus concerning one Embodiment of this invention. It is a flowchart which shows the example of the production | generation process of a glare texture. It is a figure which shows the example of a glare texture. It is a flowchart which shows the example of the drawing process of a passage object. It is a figure which shows the example of the vertex and normal line of a rain object. It is FIG. (1) which shows the process example based on the vertex and normal of a rain object. It is a figure which shows the example of view space and projection space. It is FIG. (2) which shows the process example based on the vertex and normal of a rain object. It is a figure which shows the example of a depth information texture. It is a figure which shows the example of a production | generation image.

  Hereinafter, preferred embodiments of the present invention will be described.

<Configuration>
FIG. 1 is a diagram illustrating a configuration example of an image processing apparatus according to an embodiment of the present invention.

  In FIG. 1, the image processing apparatus includes a 3D application (3D application program) 2 including a drawing command of a 3D (3 Dimension) object such as a game application, and a 3D such as OpenGL or Direct3D that receives a drawing command or the like from the 3D application 2. An API (Application Program Interface) 3 and a GPU (Graphics Processing Unit) 4 that executes drawing processing are provided. Although not shown, the execution environment of the 3D application 2 and 3D-API 3 is a general computer CPU (Central Processing Unit), ROM (Read Only Memory), RAM (Random Access Memory), HDD ( Hardware resources such as Hard Disk Drive) are provided.

  The GPU 4 receives a GPU command and a data stream from the 3D-API 3, performs a coordinate transformation (matrix transposition) and the like by receiving 3D vertex data from the GPU front end 41 and projecting it to the 2D screen space. A programmable vertex processor (VS) 42 and a basic assembly unit 43 that assembles a vertex index stream supplied from the GPU front-end unit 41 and vertex data coordinate-converted by the programmable vertex processor 42 are provided. The parts of the programmable vertex processor 42 and the basic assembly unit 43 are called vertex shaders.

  In addition, the GPU 4 performs rasterization / interpolation unit 44 that performs rasterization and interpolation from the polygon, line, and point data assembled by the basic assembly unit 43, and rasterized pixel (fragment) data from the rasterization / interpolation unit 44. A raster processing (pixel data of pixel data) is received from a programmable pixel processor (PS: Pixel Processor) 45 that receives and performs texture mapping, a pixel position stream given from the rasterizing / interpolating unit 44, and texture mapped data given from the programmable pixel processor 45. And a raster calculation unit 46 that performs arrangement on the screen. The portions of the rasterizing / interpolating unit 44, the programmable pixel processor 45, and the raster computing unit 46 are called pixel shaders.

  In the GPU 4, the rendering content is written / updated by the raster computing unit 46, the glare texture 471 and the depth information texture 472 that can be referred to / updated from each unit in the GPU 4, and the rendered content is rendered by the raster computing unit 46. And a frame buffer 48 to be written and updated.

  The glare texture 471 and the depth information texture 472 are used in the drawing process of the rain object. The glare texture 471 will be described later, including its generation process.

  The depth information texture 472 is a texture that holds depth information (z-direction distance from the viewpoint) of each pixel of the drawing frame. The texture is map data that holds values corresponding to the U coordinate (generally 0 ≦ U ≦ 1) and the V coordinate (generally 0 ≦ V ≦ 1) of the texture space. Since the texture generally has a format for holding color information data, when information other than the color information is held, it is converted into the color information format and stored.

  The content written in the frame buffer 48 is periodically read out and converted into a video signal and displayed by a monitor device or the like.

  Data necessary for processing is held in the data holding unit 5. Main data includes model data, model posture, viewpoint, viewing direction, and angle of view. The model data includes material, vertex coordinates, normal, texture, and vertex color (diffuse color).

  The model data is polygon data representing the form of the model in the virtual three-dimensional space in the standard posture. A model that is instantiated and placed in a virtual three-dimensional space may be referred to as an object. Since a rain object described later has a simple configuration, it can be generated directly from a program without being stored as a model. The material is information for distinguishing the type of model, and a self-emission value (Emissive) is set in the case of an object that emits light like a streetlight. The vertex coordinates are coordinates (x coordinate, y coordinate, z coordinate) of the polygon of the model. The normal is a vector value indicating the direction in which each vertex faces. The texture is image data that is pasted on the surface of the polygon. The vertex color is a value such as RGB (Red Green Blue) indicating the color of each vertex.

  The model posture is a value indicating the position and rotation angle of each model in the virtual three-dimensional space. The viewpoint, the viewing direction, and the angle of view are the three-dimensional position, the line-of-sight center direction, and the viewing angle of the virtual camera (virtual viewpoint) when the model in the virtual three-dimensional space is drawn as a two-dimensional image on the projection plane.

  Although the configuration using the GPU 4 for the image processing apparatus 1 has been described, it goes without saying that the present invention can also be applied to a case where a graphic engine is realized by software on general-purpose computer hardware. In this case, the function of the GPU 4 is realized by software like the 3D application 2 and 3D-API 3, and the textures 471 and 472 and the frame buffer 48 are arranged on a memory (RAM).

<Operation>
FIG. 2 is a flowchart showing an example of the generation process of the glare texture 471. The glare texture 471 is a texture that stores color information for each pixel of a light emitting portion of a model (self-luminous object) in which a self-luminous value is set for the material. The generation process of the glare texture 471 is mainly performed by a pixel shader.

  In FIG. 2, when processing is started every frame or every several frames (step S101), the pixel of the model in which the self-luminous value is set for the material is drawn on the glare texture 471 that is a texture buffer prepared in advance (step S101). S102), the process is terminated (step S103).

  FIG. 3 is a diagram showing an example of the glare texture 471, and shows the emission color for each pixel. In the figure, a streetlight having six cubic light-emitting portions is arranged at the center of the screen, and a part of other streetlights can be seen at the right end of the screen. In the figure, the white part is a part with high emission intensity, and the black part is a part with low emission intensity.

  FIG. 4 is a flowchart showing an example of a passing object drawing process. As the passing object, for example, a rain object expressing a rain stripe, a snow object expressing a snow grain, a water drop object expressing a splash generated in a fountain, and the like are assumed. Hereinafter, the present invention will be described in detail with respect to a rain object as an example of a passing object.

  It should be noted that normal drawing processing is performed on the polygons of other models excluding the passing object, and the result is combined on the frame buffer 48 with the drawing processing result of the passing object.

  In FIG. 4, when the process is started every frame or every several frames (step S201), a rainfall range (range of x, y, z values) is set (step S202).

  Next, a rain object is generated within the set rain range (step S203). The rain object starts from the maximum y coordinate of the rainfall range and updates the coordinate every time based on a predetermined velocity vector until it reaches the minimum y coordinate and disappears. FIG. 5A shows an example of a rain object. Here, a rain line (rain line) is expressed by a line polygon connecting five vertices VT1 to VT5. Note that the number of vertices is not limited to five, and the intervals between the vertices need not be equal. The apex need not be along a straight line, but may be along a curved line. Moreover, although the rain line falling in the vertical direction is shown in the figure, the rain may fall in an oblique direction, and in that case, the apex is arranged in the oblique direction.

  Next, a process for obtaining neighboring coordinates located around the vertex coordinates is performed. Returning to FIG. 4, a vector in which a value is set only on the y-axis is set to the normal line paired with each vertex of the rain object (step S204). The y-axis value of the vector is, for example, 1.0 to −1.0 from the top vertex to the bottom vertex. FIG. 5B shows a normal (0, 1, 0) at the vertex VT1, a normal (0, 0.5, 0) at the vertex VT2, a normal (0, 0, 0) at the vertex VT3, and a vertex VT4. The normal line (0, -0.5, 0) and the normal line (0, -1, 0) are set on the vertex VT5.

  Next, returning to FIG. 4, processing by the vertex shader is performed (step S205).

  First, vectors v1 ′ and v2 ′ are calculated by adding a vector v1 having a value set in the positive direction of the x-axis and a vector v2 having a value set in the negative direction of the x-axis to the normal of each vertex of the rain object. (Step S206). The absolute value of the x-axis values of the vectors v1 and v2 is a predetermined scaling value. FIG. 6 conceptually shows the processing contents, and shows a state in which the vectors v1 ′ and v2 ′ are obtained by adding the vector v1 and the vector v2 to the normal (vector) of the vertex VT1, respectively. The vectors v1 ′ and v2 ′ obtained here are the neighboring coordinates in the three-dimensional space. Similarly, vectors v1 ′ and v2 ′ are obtained for the other vertices VT2 to VT5. Each vector obtained by multiplying the vectors v1 ′ and v2 ′ obtained by the above procedure by a coefficient may be used as the neighborhood coordinates.

  Next, returning to FIG. 4, each vertex of the rain object is multiplied by a known view transformation matrix, and the vertex coordinates of the rain object moved to the view space are calculated (step S207).

  FIG. 7A shows an example of a view space. The view space is a coordinate space based on the viewpoint (virtual camera) VP, and the horizontal axis is the x axis, the vertical axis is the y axis, and the depth is the z axis with respect to the viewing direction from the viewpoint VP. A near clip plane CP1 is set on the side closer to the viewpoint VP, and a far clip plane CP2 is set on the far side within the range where the angle of view is swung in the x axis direction and the y axis direction with respect to the viewing direction of the viewpoint VP. Is done. The hexahedron surrounded by the near clip plane CP1 and the far clip plane CP2 and the plane showing the angle of view is called a view frustum, and a model (object) arranged inside is a drawing target. In the case of a video game, the position of the viewing frustum is determined so as to include a player character operated by an operation means by a player (player). FIG. 7B shows an example of a projection space, and the view space shown in FIG. 7A is converted into ranges of −1 ≦ x ≦ 1, −1 ≦ y ≦ 1, and 0 ≦ z ≦ 1. It is a thing.

  Next, returning to FIG. 4, view space coordinates p1 and p2 obtained by adding the vertex coordinates of the rain object in the view space to the vectors v1 ′ and v2 ′ are calculated (step S208).

  Next, the projection space coordinates p1 ′ and p2 ′ are calculated by multiplying the view space coordinates p1 and p2 by a known projective transformation matrix (step S209).

Next, texture space coordinates p1 "and p2" are calculated from the projection space coordinates p1 'and p2' (step S210). The conversion formula is, for example,
pi "(x) = 0.5.pi '(x) +0.5
pi "(y) =-0.5.pi '(y) +0.5
Is used. FIG. 8 shows a state where the vectors v1 and v2 are added to the normal line of the vertex VT1 of the rain object, and the texture space coordinates p1 ″ and p2 ″ are obtained through various transformations. The p1 "and p2" obtained here are the near coordinates on the texture space.

  Next, returning to FIG. 4, processing for each pixel by the pixel shader is performed (step S211).

  First, the color information c1 and c2 are acquired from the glare texture 471 (FIG. 3) using the texture space coordinates p1 ″ and p2 ″ (step S212).

  Next, depth information d1 and d2 are acquired from the depth information texture 472 using the texture space coordinates p1 "and p2" (step S213). FIG. 9 shows an example of the depth information texture 472, and shows values in the same scene as the example of the glare texture 471 of FIG. In the depth information texture 472, a higher luminance is set for a pixel corresponding to a self-luminous object closer to the viewpoint side. That is, in FIG. 9, the white portion indicates that the object exists at a position close to the viewpoint side, and the black portion indicates that the object exists at a position far from the viewpoint.

  Next, returning to FIG. 4, the color information c1 is multiplied by the depth information d1 as the luminance value to calculate the color information c1 · d1, and the color information c2 is multiplied by the depth information d2 as the luminance value to obtain the color information c2 · d2. The color information D obtained by adding the color information c1 · d1 and the color information c2 · d2 is calculated (step S214). The reason why the color information is multiplied by the depth information is to give strength to the color information of the extracted self-luminous object depending on the distance.

  Next, the color information D is added to the diffuse color at the vertex of the rain object, and the color is set as the vertex output color (the output color to the frame buffer 48) (step S215).

  After setting the output color for all the vertices set in the rain object, the output color of the pixels between the vertices is interpolated and calculated based on the output color of each vertex that has already been set. Then, the output color of the entire rain object is set (step S216), and the process ends (step S217).

  As described above, in the process illustrated in FIG. 4, the neighbor coordinates (texture space coordinates p1 ″ and p2 ″) located in the vicinity of each vertex of the rain object are calculated, and the rain object is added with the color information of the neighbor coordinates. Execute the process to set the output color of the vertex. Thereby, when a passing object such as a rain object passes around a light source such as a streetlight, it is possible to express rain glare or the like in which rain lines shine.

  FIG. 10 is a diagram illustrating an example of a generated image, in which a rain line falling around the street lamp at the center of the screen is partially illuminated by the streetlight.

<Summary>
As described above, according to the present embodiment, in order to determine the output color of the rain object from the vertex information of the rain object, the color information at the coordinates in the vicinity thereof, and the depth information, the street light etc. There is an advantage that rain glare in which rain streaks around the light source shine can be expressed by the light emitted by.

  In addition, according to this embodiment, in order to make the setting of the output color of the rain object a simpler process, the case where the rain stripe is formed by the line polygon has been described. However, the present invention is not limited to this, and the width is not limited. The present invention can also be applied to a case in which rain stripes or snow grains are expressed by polygons (for example, rectangular shape or circular shape).

  Further, according to the present embodiment, the top vertex of the rain polygon is affected by the light source of the upper position coordinate, and the bottom vertex of the rain polygon is affected by the light source of the lower position coordinate, In order to express more natural rain glare, the case where the normal value is set to set the coordinates above the upper end position and near the lower end position as the neighboring coordinates has been described. The normal value of each vertex may be any value as long as the coordinates in the vicinity of the vertex coordinates can be acquired.

  Further, according to the present embodiment, the case where rain glare is expressed with less wasteful processing by calculating the neighborhood coordinates using normal values that are not normally used in the line polygon has been described. However, the present invention is not limited to this, and the present invention can also be applied to a case in which the neighborhood coordinates are obtained by adding a predetermined vector to each vertex coordinate without setting the normal value of each vertex.

  Further, according to the present embodiment, in order to generate a more natural rain object with simple processing, two neighboring coordinates are calculated using the normal value for each vertex, and the color information of each neighboring coordinate is obtained. Although the case of adding to the output color of the vertex has been described, the number of neighboring coordinates is not limited to two, but may be one point, or three or more may be calculated.

  The present invention has been described above by the preferred embodiments of the present invention. While the invention has been described with reference to specific embodiments, various modifications and changes may be made to the embodiments without departing from the broad spirit and scope of the invention as defined in the claims. Obviously you can. In other words, the present invention should not be construed as being limited by the details of the specific examples and the accompanying drawings.

1 Image processing device 2 3D application 3 3D-API
4 GPU
41 GPU front end part 42 Programmable vertex processor 43 Basic assembly part 44 Rasterization / interpolation part 45 Programmable pixel processor 46 Raster operation part 471 Glare texture 472 Depth information texture 48 Frame buffer 5 Data holding part

Claims (6)

Computer
Coordinate conversion means for setting a virtual viewpoint for a virtual space in which an object including at least a self-luminous object is arranged, and projecting the object arranged inside the viewing frustum based on the virtual viewpoint onto a projection plane;
Passing object generating means for generating a passing object passing around the self-luminous object in the virtual space;
Holding means for holding color information of the self-luminous object in the virtual space and depth information of the object in a memory for each pixel of the projection plane;
Neighborhood coordinate calculation means for calculating neighborhood coordinates of the passing object on the projection plane;
Color information acquisition means for acquiring color information and depth information of the self-luminous object in the vicinity coordinates calculated from the holding means, and multiplying the color information and depth information to acquire influence color information;
An image processing program for functioning as color setting means for reflecting acquired influence color information on the color of the passing object. An image processing program according to claim 1,
The color information acquisition means acquires influence color information that brightens the color of the passing object as the depth of the self-luminous object in the neighboring coordinates is smaller.
The color setting means is an image processing program for setting the color of the passing object brighter as the depth of the passing object is smaller. An image processing program according to claim 2,
The passing object generating means randomly generates the passing object as a line polygon composed of a plurality of vertices, and gives a speed of falling in the virtual space,
The color information acquisition means acquires influence color information by multiplying color information and luminance information of the neighboring coordinates for each vertex,
The color setting means is an image processing program for reflecting the influence color information on the color of each vertex of the passing object. An image processing program according to claim 3,
Computer
A vector of positive values is set for the y-axis value for the top vertex of the passing object, and a negative value vector is set for the y-axis value for the bottom vertex. Function as a vector setting means for setting a vector,
The neighborhood coordinate calculation means adds two vectors each having an x-axis value in the positive direction and an x-axis value in the negative direction to a vector set at each vertex of the passing object,
The color information acquisition unit is an image processing program for acquiring influence color information by adding a multiplication value of color information and depth information obtained from coordinates on the projection plane corresponding to the two added vectors. An image processing program according to claim 4,
Computer
A vector is set with a y-axis value of +1 for the top vertex of the passing object and a y-axis value of -1 for the bottom vertex, and a vector is set continuously between the vertices between them. Function as a vector setting means,
The neighborhood coordinate calculation means adds two vectors each having an x-axis value of +1 and an x-axis value of −1 to a vector set at each vertex of the passing object,
The color information acquisition unit is an image processing program for acquiring influence color information by adding a multiplication value of color information and depth information obtained from coordinates on the projection plane corresponding to the two added vectors.   A computer-readable recording medium for recording the image processing program according to any one of claims 1 to 5.