JPH06176168A - Computer graphics preparing device - Google Patents

Abstract

PURPOSE:To easily prepare the two-dimentional projected image of an object in which a continuous pattern is mapped on mutually adjacent surfaces at the time of CG image production. CONSTITUTION:A shape input device 10 outputs shape data expressing the shape of the object composed of plural polygons by the coordinate value of each vertex and the sequence of vertexes defining the polygons to a development elevation generator 12. The device 12 prepares a development elevation developing all the polygons composing the object shape based on the piece of data. A projected image producing device 18 executes mapping by overlapping a texture image inputted from a texture image input device 14 to the development elevation, executes texture mapping at the time of generating the projected image based on a texture coordinate value given to a vertex coordinate as the development elevation at this time and specifies the position of the shape based on input information from a shape position, light and camera information input device 16 to specify the position of the light, the position of the camera, etc., to produce the two-dimentional projected image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer graphics production apparatus, and more particularly to a computer graphics production apparatus suitable for producing a projection image in which a continuous pattern is mapped on a surface adjacent to an object surface. Regarding production equipment.

[0002]

2. Description of the Related Art Computer graphics (CG)
Image production, eg CG calendar, CG hologram,
In the production of CG animation, CG commercials, CG posters, high-definition CG still image programs, etc.
When creating an image in which a continuous pattern such as wallpaper or a building material pattern is pasted on the surface (three-dimensional shape) of an object, it may be desirable to express a continuous pattern (pattern) on the adjacent surfaces that make up the object surface. .

As described above, in order to express a continuous pattern on the adjacent surface of the object surface in CG, it is usually necessary to perform continuous texture mapping on the adjacent surface of the three-dimensional shape corresponding to the object surface. is there. In this case, the coordinate values of each vertex of the three-dimensional shape represented by the three-dimensional coordinates (x, y, z) can be associated with the two-dimensional texture coordinates (u, v) that describe the position of the texture such as wallpaper. Be seen.

Conventionally, as described above, the operator develops the shape of an object described in xyz coordinates on the uv plane and associates the coordinate value of each vertex of the three-dimensional shape with the uv coordinate value by one point. I was manually inputting while calculating each.

[0005]

However, as described above, it is very difficult to associate the respective vertex positions of the object shape described by the three-dimensional coordinates with the two-dimensional texture coordinates one by one. However, there is a problem that it is extremely difficult to perform a mapping calculation that takes into account continuity for a particularly large and complicated shape.

Further, if it is necessary to change the mapping state after performing texture mapping on the object surface, it is necessary to perform the same calculation and the like again, so that the mapping state can be easily changed. There is a problem that you can not.

The present invention has been made to solve the above-mentioned conventional problems, and in computer graphics image production, a two-dimensional projection image of an object in which a continuous pattern is mapped on adjacent surfaces can be easily performed. It is an object of the present invention to provide a computer graphics production device capable of producing.

[0008]

The present invention provides a computer graphics production apparatus for producing a two-dimensional projection image of an object whose surface is texture-mapped.
A development view output means for outputting a development view obtained by developing a plurality of polygons forming a three-dimensional shape of the object surface, and a development texture input from the development view output means, with a texture image for mapping superimposed thereon, The above object is achieved by a configuration including an image production unit that produces a projection image based on the mapped development view.

According to the present invention, in the computer graphics production apparatus, the development view output means defines a polygon defined by position coordinates of a three-dimensional coordinate system that describes vertices of a three-dimensional shape of an object surface. The expanded polygon is expanded to a two-dimensional coordinate system for texture mapping using the position coordinates, and an expanded polygon sharing an edge with the expanded polygon expanded to the two-dimensional coordinate system is selected, and the expanded polygon is the expanded polygon. And two end points P1 and P of the side shared in the three-dimensional coordinate system
The distances d 1 and d 2 from 2 to the expansion target vertex Pt are calculated, and two candidate points Pa at positions corresponding to the distances d 1 and d 2 from the two end points P1 and P2 in the two-dimensional coordinate system are calculated. , Pb are calculated and the candidate points Pa, P are calculated.
Among b, a point located on the side opposite to the expanded polygon is selected with reference to the shared side, and the operation of setting the coordinate value of the point as the two-dimensional coordinate value of the expansion target vertex Pt is sequentially executed, The above-mentioned problem is similarly achieved by adopting a structure having a function of automatically expanding polygons forming a three-dimensional shape.

[0010]

In the present invention, the development view of the object shape is used when the two-dimensional projection image in which the surface of the object is texture-mapped is produced. Therefore, each vertex of the object shape in the development view is used. By assigning texture coordinate values (u, v) corresponding to
It is possible to perform continuous texture mapping according to the development view, and it is possible to easily perform arbitrary texture mapping such as pasting continuous patterns on two adjacent surfaces.

Therefore, based on the texture coordinate values given to the vertex coordinates as a developed view as described above, texture mapping is performed at the time of generating the projected image, and the projected image is produced in accordance with the usual method, so that the desired adjacent surface is produced. It becomes possible to easily produce a two-dimensional projection image of an object to which a continuous pattern is attached.

When the texture mapping state is changed, the relative positional relationship between the developed image developed on the texture coordinates and the texture image superimposed on the developed image or the size of the texture image is changed. This makes it possible to easily change the mapping state.

Further, in the present invention, a plurality of polygons forming a three-dimensional object shape are uv for texture mapping.
If you have a function that automatically expands to the coordinate system,
It is not necessary for the operator to calculate the coordinates of the development view one by one and input the coordinates of the calculation result, and it is possible to significantly reduce the load of the computer graphics production work for producing the projection image on which the texture mapping is applied. .

[0014]

Embodiments of the present invention will now be described in detail with reference to the drawings.

FIG. 1 is a block diagram conceptually showing a computer graphics production apparatus according to an embodiment of the present invention.

The computer graphics production apparatus according to the present embodiment has a shape input device 10 for inputting data relating to the shape of an object, and a three-dimensional object based on the data relating to the object shape inputted from the shape input device 10. A development view generation device 12 that develops a shape in a two-dimensional texture coordinate system and automatically generates a development view, and a texture image input device 14 that inputs a texture image for mapping.
And a shape position / light / camera information input device 16 for inputting information about the position of the object shape, the light, the camera, and the like.
Based on the texture coordinate values given to the vertex coordinates as the development view input from the development view generation device 12, texture mapping is performed when the projection image is generated, and the shape position / light / camera information input device 16 is used. A projection image production apparatus 18 for identifying the position of the three-dimensional shape mapped based on the input shape position information and creating a two-dimensional projected image of the three-dimensional shape mapped based on the light information and the camera information. There is.

The computer graphics production apparatus of this embodiment will be described in detail. The shape input apparatus 10 determines the shape of an object composed of a plurality of polygons, the coordinate value of each vertex, and the arrangement of the vertices defining the polygon. It has the function of inputting with (row).

Specifically, each vertex of the object shape uses, for example, P1 (x 1, y 1, z 1) and P 2 (x using xyz coordinates.
2, y 2, z 2), ..., and the polygon is defined as S1 (P1, P2, P3, P4), S2 using the vertices P1, P2, ... Specified by the xyz coordinate values. (P5,
P6, P2) ... If the object is a cube, which will be described later, all of the polygons are defined by four vertices because they are all formed by quadrangular surfaces.

The development drawing generator 12 is a shape input device 10.
The shape of the object is read by the coordinate values of the above-mentioned vertices describing the shape and the vertex row, and a developed view of the shape is automatically generated based on the information, and the shape is used as the texture coordinate value. It has a function to register.

In this device 12, the developed view is registered as the shape data of the object. The shape data used to register this development view is the spatial coordinates (x, y, z) that define each vertex.
) Value and the texture coordinate (u, v) value corresponding to each spatial coordinate value, and the arrangement of vertices defining the polygon (vertex row) and the parent polygon ID indicating the parent-child relationship of each polygon. It is composed of a combination. An example of defining the vertex and an example of defining the polygon are shown below.

[Apex definition example] P1 (x 1, y 1, z 1) (u 1, v 1) P2 (x 2, y 2, z 2) (u 2, v 2) [Polygon definition example] S1 (P1, P2, P3, P4) (route) S2 (P5, P6, P2) (S1)

In the above polygon definition example, (root) indicates that the polygon S1 is a root polygon, and (S)
1) shows the parent polygon ID. This parent polygon I
D indicates that the polygon S1 is a parent polygon of the polygon S2, that is, the polygon S2 is a child polygon of the polygon S1.

The texture image input device 14 has a function of inputting a texture image used for performing texture mapping on the surface of an object to the projection image production device 18.

The shape position / light / camera information input device (hereinafter, also simply referred to as an information input device) 16 arranges an object input by the shape input device 10 when producing a projected image, a light position, etc. Has a function of inputting the light information and camera information such as a camera position to the projection image production apparatus 18.

The projection image production device 18 includes a development view generation device 12, a texture image input device 14, and an information input device 16.
It has a function of reading the data from each of them and producing a two-dimensional projected image of the target object based on the data.

Next, the operation of this embodiment will be described.

2 to 4 are flow charts showing an example of a method for automatically generating a development drawing in the development drawing generating device 12. Here, the automatic generation method of this development view will be described in detail by taking the case of developing the cube shown in FIG. 5 as an example.

First, the shape input device 10 develops a list of three-dimensional coordinate values for each of the vertices P1, P2, ... And a list of vertex sequences S1 (P1, P2, P3, P4) defining each polygon. It is input to the generator 12 (step 110).

In the development drawing generator 12, a root polygon (S1 in FIG. 5) to be the starting point of the development is selected based on the input data (step 112), and the root polygon S1 is set as shown in FIG. , On the uv plane representing the texture coordinate system (step 114). The development of this root polygon may be performed at any position and orientation on the uv plane as long as the polygon shape and size are maintained.

Next, at step 116, it is judged whether or not there is an unexpanded polygon that shares an edge with the expanded root polygon, and if No, the process returns to step 112 to select a new root polygon. If yes,
As shown in FIG. 7, the expanded polygon S2 to be expanded next is selected (step 118).

The operation of expanding the selected polygon S2 on the uv plane shown in FIG. 6 is performed as follows. First, as shown in FIG. 8, of the vertices of S2 to be expanded, one vertex Pd which is not shared with S1 is selected (step 120), and the vertices at both ends of the shared edge in the world coordinate system of xyz space are selected. Distances d1 and d2 between the located vertices P1 and P2 and the developed vertices Pd are calculated (step 122).

Next, using the calculated distances d1 and d2 in the world coordinate (xyz) system, as shown in FIG. 9, in the texture coordinate system in the uv space, the distance d from the vertex P1.
1, the position corresponding to the distance d2 from the vertex P2 (for convenience, xy
Two points Pa, P in the same symbol as the z coordinate system)
The texture coordinate value of b is calculated (step 124), and of these two texture coordinate values Pa and Pb, the point (coordinate value P that is located on the side opposite to the parent polygon S1 with respect to the shared side).
b) is selected and used as the texture coordinate value of the developed vertex Pd (step 126).

After determining the texture coordinate value of the developed vertex Pd, it is determined in step 128 whether or not all the vertices of the developed polygon (child polygon) S2 have been developed. If No, step 120 8, the vertex Pe is expanded in the case of FIG. 8 by the same method as the case of the vertex Pd, and in the case of Yes, the next step 130
Then, it is judged whether all polygons have been expanded, and No
In the case of, the process returns to step 116 and the above-mentioned operation is repeated.

In step 132, scaling is performed as post-processing to normalize the uv coordinate values of the developed view so that processing such as texture mapping to be performed later can be easily performed on the developed view in which all the polygons are developed. Then, all the operations for generating the development view are completed. It should be noted that, in the scaling, if the developed view finally obtained is, for example, as shown in FIG. 10, the entire developed view is put in a range of 0 to 1 for both the u coordinate value and the v coordinate value. Means to perform scaling and translation.

By the above operation, the development drawing generating device 1
The development view information corresponding to the normalized development view created in step 2, that is, P1 (x 1, y 1, z 1) that defines each vertex
A combination of coordinate values such as (u 1, v 1) and uv plane coordinate values,
And S1 (P1, P2, P3, P
4) The combination of the vertex array such as 4) and the parent polygon ID indicating the parent-child relationship of the polygon is input to the projection image production device 18,
Based on the information, the developed view shown in FIG. 10 is displayed on the screen, and the texture image input from the texture image input device 14 is superimposed on the developed view in a desired state. Texture mapping is performed at the time of generating a projected image based on the texture coordinate value given to the coordinate.

Based on the information input from the information input device 16, the position of the texture-mapped cube shape on the image is specified, and the positions of the light and the camera are also specified to generate a two-dimensional projection image. create.

As described above in detail, according to this embodiment,
Since the development drawing generator 12 can automatically generate a development drawing of the object shape, the three-dimensional coordinate values of the object shape and
Since it is not necessary to manually associate each point with the three-dimensional texture coordinate value, for example, computer graphics of an object in which a continuous pattern is mapped to two adjacent desired faces sharing an edge. It is possible to produce a projected image by using the method very easily.

Although not shown, the mapping state can be easily changed by changing the relative position and dimension relationship between the developed view on the uv plane and the texture image superimposed on the developed view. Therefore, it is possible to quickly create a projection image of an object on which a desired texture is mapped.

Although the present invention has been specifically described above, the present invention is not limited to the above-described embodiments, but various modifications can be made without departing from the scope of the invention.

For example, although the case where the object shape is a cube is shown, the present invention is not limited to this, and the present invention can be applied to an object having an arbitrary shape. Therefore, the polygon forming the three-dimensional shape is not limited to a quadrangle, and may be a triangle.
Needless to say, it may be a pentagon or more.

Further, according to the present invention, a development drawing generating device 1
The method is not limited to the case where it is automatically generated in 2, and a developed view (information) created by another method may be used.

[0042]

As described above, according to the present invention, when texture mapping is performed on the surface of an object in computer graphics production, a developed view of the object shape is used. It becomes possible to perform the matching very easily, and as a result, it becomes possible to easily produce a two-dimensional projection image of the object subjected to the texture mapping.

Further, when the means for automatically generating the development view of the object shape is used, there is no need to manually perform the coordinate calculation of the development view and the coordinate input of the calculation result, so that it is much easier. It is possible to produce a two-dimensional projected image of an object, and it is possible to improve the efficiency of computer graphics production work.

[Brief description of drawings]

FIG. 1 is a block diagram showing a schematic configuration of a computer graphics production apparatus according to an embodiment of the present invention.

FIG. 2 is a flowchart showing the operation of the embodiment.

FIG. 3 is another flowchart showing the operation of the embodiment.

FIG. 4 is still another flowchart showing the operation of the embodiment.

FIG. 5 is a diagram showing a relationship between an input object shape and a root polygon.

FIG. 6 is a diagram showing a root polygon developed on the uv plane.

FIG. 7 is a diagram showing a relationship between a shared edge and an expanded polygon.

FIG. 8 is a diagram showing a relationship between distances between developed vertices and end points of shared sides.

FIG. 9 is a diagram showing candidate points of developed vertices in a texture coordinate system.

FIG. 10 is a diagram showing an example of a development diagram after the development is completed.

[Explanation of symbols]

 10 ... Shape input device 12 ... Development view generation device 14 ... Texture image input device 16 ... Shape position / light / camera information input device 18 ... Projection image production device

Claims (2)

[Claims] 1. A development view obtained by developing a plurality of polygons forming a three-dimensional shape of an object surface in a computer graphics production apparatus for producing a two-dimensional projection image of an object whose surface is texture-mapped. A development image output means for outputting the image, and an image production means for superimposing a texture image for mapping on the development image input from the development image output means and producing a projection image based on the mapped development image. Computer graphics production equipment characterized by: 2. The texture mapping according to claim 1, wherein the development drawing output means uses a polygon defined by position coordinates of a three-dimensional coordinate system that describes vertices of a three-dimensional shape of an object surface by using the position coordinates. Is expanded to a two-dimensional coordinate system for use, and an expanded polygon which shares an edge with the expanded polygon expanded to the two-dimensional coordinate system is selected, and the expanded polygon is shared with the expanded polygon in the three-dimensional coordinate system. The distances d 1 and d 2 from the two end points P1 and P2 of the side to the expansion target vertex Pt are calculated, and the two end points P1 and P2 are respectively calculated in the two-dimensional coordinate system.
Two candidate points P located at positions corresponding to the distances d 1 and d 2.
The coordinate values of a and Pb are calculated, and of the candidate points Pa and Pb, a point located on the opposite side of the developed polygon is selected based on the shared side, and the coordinate value of the selected point is used as the development target vertex. A computer graphics production apparatus characterized in that it has a function of automatically executing the operation of setting the two-dimensional coordinate value of Pt to automatically develop a polygon forming a three-dimensional shape.