JPH1097646A - Method and device for obtaining three dimensional space coordinate value in three-dimensional space display system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To precisely and speedily obtain a three-dimensional space coordinate by obtaining a coordinate point in a three-dimensional space corresponding to a select- indicated coordinate point on a two-dimensional video through the use of a vector obtained by inverse transformation of a transforming method at the time of transforming a three-dimensional space shape to a two dimensional video. SOLUTION: At the time of displaying three-dimensional objects B1 and B2 on a display device 3 and select-indicating a desired point A on the displayed two-dimensional video, the indicated point A select-indicated on the two-dimensional video is obtained as coordinate data to obtain a coordinate value on the three-dimensional objects corresponding to the indicated point. At the time, a three-dimensional vector passing through an index point A is first obtained from a view point E and next, an intersecion point between the three-dimensional vector and the three-dimensional object in the three-dimensional space is calculated to obtain the three-dimensional coordinate value of intersection points C1 to C4. After then, a desired processing is executed to the three-dimensional space by the obtained three-dimensional coordinate value.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional space display system, and more particularly, converts a three-dimensional space shape observed from a predetermined viewpoint position into a two-dimensional image based on three-dimensional space shape information and viewpoint information and displays the two-dimensional image. The present invention relates to a method and an apparatus for acquiring three-dimensional space coordinates in a three-dimensional space display system.

[0002]

2. Description of the Related Art As a three-dimensional space display system as described above, for example, a three-dimensional visual simulation system that provides three-dimensional space information and evaluates the space, and a three-dimensional space display system that performs three-dimensional image display. Games dealing with various objects, and a three-dimensional visual interface system for selectively acquiring information in a three-dimensional spatial image.

[0003] The visualization expression using the three-dimensional spatial display system as described above provides intuitively understandable information, but since the information on the display device is a two-dimensional image, the information here is Understanding this spatial image is only two-dimensional information,
After some judgment, the object to make a decision is the three-dimensional space information, so the three-dimensional space display system cannot specify the three-dimensional space.

For this reason, when a user understands the three-dimensional image, makes some judgment as a result, decides a target three-dimensional space position, and intends to designate this as a position in the three-dimensional space, A three-dimensional spatial position measuring instrument such as a polymass sensor capable of acquiring three-dimensional spatial coordinate values (for example, see Japanese Patent Application Laid-Open No. H6-19526), an operating tool, or by itself, or a three-dimensional computer design device A rough three-dimensional spatial coordinate value is obtained or generated for the time being (hereinafter referred to as three-dimensional CAD), and is displayed on a three-dimensional display device to confirm a deviation from a target three-dimensional spatial position. If different, the operating device must be operated again in the same manner to approach the target three-dimensional space position.

In other words, in the above-mentioned conventional method, a three-dimensional space can be displayed. However, in order for a user to specify the three-dimensional space position, a special device such as a three-dimensional position measuring instrument such as a polymass sensor is used. Needed. In addition, in order to specify a target three-dimensional space position, a three-dimensional position value is generated using a three-dimensional position measuring device, a three-dimensional CAD, or the like as described above, and this is confirmed on a three-dimensional display system. However, since the corresponding point had to be obtained, the user had to determine the target point by trial and error while judging whether or not the point currently designated by the user was the target point using a measuring instrument. In other words, there is an operational problem that the user cannot specify the target point unless the user performs a complicated operation of feedback control. For this reason, the operation function as a device for realizing a sensuous expression was very poor.

On the other hand, Japanese Patent Application Laid-Open No. 7-73344 discloses that
A method and apparatus for specifying a three-dimensional coordinate corresponding to a selected two-dimensional point by selecting a point on a two-dimensional display screen in a graphic display system is disclosed. However, according to the above publication, it is possible to obtain only coordinates such as lines and surfaces which are constituent elements such as figures in three dimensions, that is, only representative points of the elements. Even if this is expanded and considered as a set of points, the set of points in those three dimensions is transformed into two-dimensional coordinates for the two-dimensional display screen, and the display screen is set from the set of points. Because it looks for something that matches the point selected above,
There are the following problems.

That is, when the above-described line or surface is regarded as a set of points, even if the line or surface has a limited length or area, the number of points existing in the line or surface is infinite. Therefore, it is practically impossible to convert all the points into two-dimensional coordinates or to find a point that matches the selected point on the screen. Therefore, it is represented as a set of approximate or pseudo finite points by some means, and when these points are projected on the screen, the three-dimensional density is such that the area on the screen corresponding to the above lines and surfaces is filled without gaps. A set of points must be generated.

[0008] However, if the set density of the above points is small, the positional accuracy of the finally obtained three-dimensional point decreases,
It may adversely affect the subsequent figure generation and other various processing processes, etc. Conversely, if the density is large, it will be converted to two-dimensional coordinates and the point of coincidence with the selected point on the screen will be searched. Takes a long time to reduce the processing speed.

[0009]

SUMMARY OF THE INVENTION The present invention has been proposed in view of the above-mentioned conventional problems, and is intended to obtain three-dimensional spatial coordinates accurately and quickly in the three-dimensional spatial display system as described above. It is an object of the present invention to provide an acquisition method and an apparatus that can perform the acquisition.

[0010]

In order to achieve the above object, a method and apparatus for acquiring three-dimensional spatial coordinates according to the present invention have the following arrangement.

That is, in the method of acquiring three-dimensional space coordinates according to the present invention, a three-dimensional space shape observed from a predetermined viewpoint position is converted into a two-dimensional image and displayed based on three-dimensional space shape information and viewpoint information. In a three-dimensional spatial display system,
By selecting and instructing a desired coordinate point on the two-dimensional image, and using the vector obtained by the inverse conversion of the conversion method when converting the three-dimensional space shape into a two-dimensional image, the two-dimensional image that has been selected and instructed is used. It is characterized in that coordinate points in a three-dimensional space corresponding to the above coordinate points are obtained.

Further, the apparatus for acquiring three-dimensional space coordinates according to the present invention includes a storage means for storing three-dimensional space shape information and viewpoint information and the like, and three-dimensional space shape information and viewpoint information and the like stored in the storage means. Image display means for converting a three-dimensional space shape observed from a predetermined viewpoint position into a two-dimensional image based on the three-dimensional space shape, and converting the three-dimensional space shape into a two-dimensional image. And a selection instructing means for selecting and instructing a desired coordinate point on the video display means to be displayed, and the selection using a vector obtained by an inverse conversion of a conversion method when converting the three-dimensional space shape into a two-dimensional video. Arithmetic processing means for obtaining a coordinate point in a three-dimensional space corresponding to the coordinate point selected and instructed by the instructing means.

[0013]

According to the method and the apparatus for acquiring three-dimensional space coordinates according to the present invention, the three-dimensional space coordinates are displayed by simply selecting and instructing a desired coordinate point on a two-dimensional image displaying the three-dimensional space shape. The vector obtained by the inverse transformation of the method of transforming the original space shape into a two-dimensional image makes it possible to accurately and quickly acquire a coordinate point in the three-dimensional space corresponding to the coordinate point selected and designated.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a method and an apparatus for acquiring three-dimensional space coordinates in a three-dimensional space display system according to the present invention will be described in detail with reference to the embodiments shown in the drawings.

The three-dimensional spatial display system has already been established as a computer system technology based on the concept of three-dimensional graphics, and its device configuration is, for example, as shown in FIG. A storage device 2 such as an external memory or a disk device,
It comprises a display device 3 such as a CRT or a liquid crystal display panel, and an input device 4 such as a keyboard and a mouse.

In displaying a three-dimensional object by the three-dimensional space display system, three-dimensional numerical data is stored in the storage device 2 and a predetermined arithmetic processing is performed by the arithmetic processing device 1 based on the numerical data. Go to display device 3
To be displayed. Specifically, for example, as shown in FIG. 2, object shape data as three-dimensional numerical data, viewpoint data, line-of-sight data, observation angle-of-view data indicating where the object is being observed from and in which direction, and further necessary. The light source data, the texture data of the object, etc. are stored in the storage device 2 in accordance with the data, and the arithmetic processing device 2 performs projection conversion (projection projection or parallel projection) based on the data to observe the three-dimensional object. The image is displayed as a two-dimensional visible image on a display screen (screen) of the display device 3 in an expression such as a plane or a line.

FIG. 3 is an explanatory diagram showing an example of projection conversion in the three-dimensional space display system. Here, an example of projection conversion by projective conversion is shown. A display device in which shape data of the three-dimensional objects B1 and B2 are projected in a direction determined by an observation viewpoint and an observation line of sight, and an image projected on an assumed projection two-dimensional plane (screen plane) as an observation angle-of-view observation image. 3 is displayed. In this case, a method of selectively projecting an object close in distance to the projection screen described above is generally used, but an ambiguous selection method such as projecting an object that is far away depending on the purpose of use of the three-dimensional image is used. It is also possible to give Such a system can be realized by either hardware or software.

In the three-dimensional space display system as described above, the operator acquires the spatial information from the two-dimensional image information on the display device 3 generated as the observation image, and the operator understands this. It determines the space and makes a decision to perform some processing on this observation space. In this case, the operator needs to acquire a coordinate point on the three-dimensional object to perform some processing, and the present invention acquires the coordinate point as follows.

That is, FIG. 4 is a flowchart showing a process of acquiring coordinate points on a three-dimensional object displayed on the display device 3 by the three-dimensional space display system as described above. First, a first step S1 is performed. As described above, the three-dimensional object B1 is determined based on the viewing angle data, the three-dimensional shape data, and the like.
B2 is displayed on the display device 3 as a two-dimensional image.

Next, as a second step S2, a desired point A on the two-dimensional image displayed on the display device 3 is selected and indicated as shown in FIG. The means for instructing the selection is appropriate. For example, the cursor or the mouse pointer is moved to a desired position and instructed by using the input device 4 such as the keyboard or the mouse as the selection instructing means. Alternatively, a coordinate value on the display screen can be input numerically from the keyboard, or a touch panel or the like can be used as the selection instruction device.

Then, the designated point A selected and designated on the two-dimensional image is acquired as coordinate data, and the coordinate value on the three-dimensional object corresponding to the designated point is acquired. As a third step S3, a three-dimensional vector passing from the viewpoint to the index point is obtained. The method and means for obtaining the three-dimensional vector are arbitrary, but can be obtained, for example, in the following manner.

That is, in the three-dimensional space display system as described above, the display is performed by projecting the object shape data into a two-dimensional image based on the observation viewpoint data as described above. Find the reverse process, perform the inverse projection transformation of the designated point on the 2D observation image,
Thereby, a three-dimensional vector can be obtained. This means, for example, that the projection conversion process knows the projection conversion process by the viewpoint position, the line-of-sight direction, the angle of view, and the projection conversion function defined as the input in the three-dimensional display system. This can be realized by obtaining a projection transformation vector corresponding to the designated point and defining the vector, and obtaining an inverse vector of this vector.

Alternatively, for example, the viewpoint position, the line-of-sight direction, the angle of view, and the viewpoint defined as the input in the three-dimensional display system described above.
Knowing the projection transformation process by the projection transformation function, defining this as a three-dimensional to two-dimensional transformation function F, finding the inverse transformation function F- ¹ , and giving the point coordinates corresponding to the designated point on the two-dimensional screen This can be realized by obtaining a vector in which only the depth direction from the viewpoint remains as a variable component.

Next, as a fourth step S4, the intersection of the three-dimensional vector obtained as described above and the three-dimensional object in the three-dimensional space is calculated, and the three-dimensional coordinate value of the intersection C is obtained. The method of obtaining the three-dimensional coordinate value of the intersection C will be described more specifically, for example, in the following manner.

That is, for example, the equation of a plane in a three-dimensional space can be expressed as the following equation (1). _{P l · x + P m ·} z + P n · Z = P ‥‥‥‥‥‥‥ (1) However, P ≧ 0 P is the distance from the origin P _l, P _m, P _n is the normal vector of the plane still , P _l , P _m , and P _n can be calculated by finding the normal line of the polygon. P can be calculated by substituting a representative value (P ₁ , P ₂ , or P ₃ ).

[0025] As the viewpoint _{E (E x, E y,} E z), a straight line directed viewing direction _{(E l, E m, E} n) and can be expressed as the following equation (2).

(X−E _x ) / E _l = (y−E _y ) / E _m = (z−E _z ) / E _n ‥‥ (2) The above equations (1) and (2) are solved. In this way, it is possible to obtain an intersection in a space between a certain polygon and a line-of-sight vector.

The above operation is applied only when there is an intersection between the polygon and the line-of-sight vector. As means for determining whether or not the intersection exists, for example, a method for mathematically determining whether or not the intersection coordinates are within the polygon,
Alternatively, it is also possible to determine whether or not the polygon includes the designated point by a known picking process generally used in a three-dimensional computer graphics system.

The specific means for obtaining the above-mentioned intersection is appropriate, for example, although not shown in the figure, the arithmetic processing is performed by the arithmetic processing unit or the like in FIG. The processing circuit may be provided in the arithmetic processing device or separately provided to perform the arithmetic processing.

Further, the intersection C in the three-dimensional space (three-dimensional object) is determined by the operator observing the two-dimensional image displayed on the display device 3 as shown in FIG. Corresponds to the point designated by the selection, but there are usually a plurality of intersections C for one target object B, and a plurality of target objects exist at the position designated by the selection. In such a case, the number of the above intersections is further increased. In this case, it is necessary to find all of the plurality of intersections C1 to C4 and select an optimum point intended by the operator or in accordance with the purpose of use of the operator. Although the optimum point depends on the display method in the three-dimensional display system, the superiority is generally determined by the distances L1 to L4 from the viewpoint E in many cases.

For example, in a normal three-dimensional display system,
In general, a display method in which a surface viewed from the viewpoint E in front is preferentially displayed, and a point selected and designated by the operator in such a display method is a viewpoint (observation point) among the plurality of intersections. Is often the optimal intersection intended by the operator or according to the purpose of use of the operator, and the intersection may be obtained. For this purpose, as shown in step S5 in FIG. 3, the plurality of intersection groups (each intersection) C1 to C4
, And calculate the distances L1 to L4 from
The intersection having the shortest distance may be selected. The above calculation and selection operation can be automatically performed by a predetermined program or a calculation circuit in the same manner as in the case of obtaining the intersection.

Depending on the display method or the like, for example, the configuration may be such that the intersection C4 furthest from the viewpoint E is obtained as an optimum point, or the other intersections C2 and C3 are obtained as optimum points. May be. Alternatively, the operator may arbitrarily select the plurality of intersections C1 to C4. For example, the plurality of intersections C1 to C4 are displayed on the display device 3 in order from the one closest to the viewpoint E so that the operator can freely select the intersections with a keyboard, a mouse, a touch panel, or the like. Is also possible.

The process or method for obtaining the three-dimensional coordinate values as described above is not limited to the case where the device is configured as an apparatus, but a program for executing the above process is stored in a floppy disk, CD-ROM, MO disk, or hard disk. It can also be configured as versatile software or circuit elements recorded on a recording medium such as a disc.

The desired processing or the like for the three-dimensional space may be performed based on the three-dimensional coordinate values obtained or obtained as described above. For example, the processing purpose for the three-dimensional space is to place a certain object there. If the purpose is to act, generate the shape data of the object to be arranged using the acquired three-dimensional coordinate values, and simply point to the point on the image by looking at the observation image on the three-dimensional display system. A three-dimensional object can be arranged at a specific position inside.

[0034]

As described above, the method and apparatus for acquiring three-dimensional space coordinate values in the three-dimensional space display system according to the present invention have the above-described configuration, and therefore the following effects can be obtained.

First, a specific position of a three-dimensional object observed by the three-dimensional display system is selected and instructed on a two-dimensional image displayed on the display device by using an input device such as a mouse or a touch panel as selection instructing means. Thus, it is possible to easily obtain three-dimensional coordinate values of the surface of the object corresponding thereto. This means that the user can directly specify the spatial coordinate values for the display information of the 3D display system using a 2D device, and that the decision making is directly reflected only by the 3D display system information. Can be. In other words, while observing the 3D display system, a mouse,
Just instruct with a two-dimensional pointing device such as a touch panel,
The corresponding three-dimensional spatial coordinate values of the displayed spatial object can be obtained.

The spatial coordinate values obtained as described above are used in, for example, a space simulation system, a virtual reality system, a three-dimensional computer graphics system, a three-dimensional game, a three-dimensional CAD system, and the like. An input system capable of directly designating spatial coordinates while handling three-dimensional spatial information can be configured.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram showing an example of a three-dimensional spatial display system to which the present invention is applied.

FIG. 2 is an explanatory diagram of a display procedure in the three-dimensional space display system.

FIG. 3 is an explanatory diagram showing an example of projection conversion in the three-dimensional space display system.

FIG. 4 is a flowchart showing a process of acquiring three-dimensional spatial coordinate values according to the present invention.

FIG. 5 is an explanatory diagram showing a relationship between a three-dimensional space coordinate value acquired by the present invention and a viewpoint.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Processing unit 2 Storage device 3 Display device 4 Input device

Claims (4)

[Claims] 1. A three-dimensional space display system for converting a three-dimensional space shape observed from a predetermined viewpoint position into a two-dimensional image based on the three-dimensional space shape information and viewpoint information, and displaying the two-dimensional image. Select and instruct the desired coordinate point, using the vector obtained by the inverse transformation of the conversion method when converting the three-dimensional space shape into a two-dimensional image, the coordinate point on the two-dimensional image selected and instructed above A method for acquiring three-dimensional space coordinate values in a three-dimensional space display system, wherein a coordinate point on a corresponding three-dimensional space is acquired. 2. When there are a plurality of coordinate points in a three-dimensional space corresponding to the coordinate points on the two-dimensional image designated and selected, the coordinate point closest to the viewpoint among the coordinate points is automatically determined. 2. The method of acquiring three-dimensional space coordinates in the three-dimensional space display system according to claim 1, wherein the method is selected and acquired. 3. When there are a plurality of coordinate points in a three-dimensional space corresponding to the coordinate points on the two-dimensional image designated and selected, the coordinate points are displayed and operated in order from the one closest to the viewpoint. 2. The method for acquiring three-dimensional space coordinates in a three-dimensional space display system according to claim 1, wherein the method is configured so that a user can arbitrarily select and acquire. 4. A storage means for storing three-dimensional space shape information, viewpoint information, and the like, and a three-dimensional image observed from a predetermined viewpoint position based on data such as three-dimensional space shape information and viewpoint information stored in the storage means. Video display means for converting the spatial shape into a two-dimensional image and displaying the converted three-dimensional spatial shape, wherein the desired three-dimensional spatial shape is converted to a two-dimensional video and displayed on the video display means. A selection instructing means for selecting and instructing a coordinate point; and a coordinate point corresponding to the coordinate point selected and instructed by the selection instructing means using a vector obtained by inverting the conversion method when converting the three-dimensional space shape into a two-dimensional image. An apparatus for obtaining three-dimensional space coordinates in a three-dimensional space display system, comprising: an arithmetic processing means for obtaining a coordinate point in a three-dimensional space.