JP3126575B2 - 3D image generator for stereoscopic vision - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement of a three-dimensional three-dimensional image generating apparatus for presenting different images based on parallax to both left and right eyes.

[0002]

2. Description of the Related Art A method of constructing a three-dimensional model of an object based on numerical data in a computer and displaying the model three-dimensionally has become important not only in the fields of numerical analysis and CAD but also in many application softwares. I have. In such a three-dimensional display, a three-dimensional model is simply projected two-dimensionally and displayed on a flat display, but in recent years, three-dimensional display is performed by presenting left and right visible images respectively. Stereoscopic vision for display is realized.

There are the following two methods for stereoscopically presenting two images for such stereoscopic viewing. (1) A method in which an image for the left eye and an image for the right eye are displayed in a time-division manner on one display, and a liquid crystal shutter or the like is displayed using glasses that open and close in synchronization with the time division. (2) A method of preparing two displays, presenting images that can be viewed from the left and right eyes on each display, and viewing the images with each eye.

In either method, when two images for stereoscopic viewing are generated, conventionally, for example, as shown in FIG.
From the perspective projection transformation to the hidden surface elimination / shading processing via the clipping processing, the left and right images are independently performed for the left and right images independently. After the obtained display data (raster data) is written into the corresponding frame buffers, it is individually displayed on each display or displayed on one display in a time-division manner. In addition, in addition to the above, there is a configuration in which all the left and right are independent of the modeling conversion.

[0005]

As described above, in the conventional apparatus, a series of processes from the perspective projection conversion to the clipping process, the hidden surface elimination process, and the shading process are independently performed for the left and right displays in an independent configuration. Is being processed. This is because, when a certain object is viewed from above as shown in FIG. 7, the images viewed from the left and right eyes are shifted from the viewpoint by the distance between both eyes, so that the object viewed by each eye is shifted. This is because the shapes and colors of the objects look different.

However, in the above-described conventional three-dimensional image generating apparatus for stereoscopic viewing, each image viewed from the left and right eyes is handled in an independent configuration, so that it is twice as large as when one image is generated. However, there is a problem that the device configuration is required. In addition, when the above-described various processes are performed in one set of left and right images, for example, in order to generate and synchronize the left and right images in order, the amount of calculation until the generation of one set of left and right images is increased. There is a problem that the processing time becomes long.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems of the prior art, and provides a stereoscopic three-dimensional image generating apparatus capable of simplifying the apparatus configuration and reducing the amount of calculation as a whole. As an issue.

[0008]

To solve the above problems, the present invention has the following arrangement. That is, the present invention
In a stereoscopic three-dimensional image generating apparatus that generates an image for the left eye and an image for the right eye and displays them on the left and right eyes, respectively, the viewpoint is placed at the center of the left and right eyes on the three-dimensional model data of the display target. and a visual field coordinate conversion processing means for converting the visual field coordinate system, and the steric effects realized processing means for applying a process to achieve a three-dimensional visual effect on the processing result of the visual field coordinate conversion processing means, the processing of the three-dimensional effect achieved processing means The resulting pixel data
Data to the value in the Z-axis direction in the view coordinate system from the viewpoint
For example, shift to the left or right so that the image for the left eye and the image for the right eye
A three-dimensional image generating apparatus for stereoscopic vision , comprising: a left-right shift processing unit that generates an image.

[0009]

[0010]

In the present invention configured as described above, one image recognized when stereoscopically viewing the left and right images is:
Utilizing the fact that the image is similar to an image obtained by placing the viewpoint at the center of the left and right eyes, processing until raster data is obtained is performed assuming that the viewpoint is placed at the center of the left and right eyes. That is, after the three-dimensional model data of the display object is converted into a visual field coordinate system in which the viewpoint is placed at the center of the left and right eyes by the visual field coordinate conversion processing means, the processing of the visual field coordinate conversion processing means is performed by the three-dimensional effect realization processing means. A process for realizing a three-dimensional visual effect is added to the result.

The left and right shift processing means includes a viewpoint difference, that is, a difference between a tentatively set viewpoint (the center of the left and right eyes) and a viewpoint of each of the right and left eyes in the processing result (raster data) of the three-dimensional effect realization processing means. To the left and right according to the
Generate an image for the left eye and an image for the right eye. The left and right image data thus obtained are written into, for example, a frame buffer and displayed on the left and right displays.

[0012]

Next, an embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a functional block diagram showing a configuration of an embodiment of a stereoscopic three-dimensional image generating apparatus according to the present invention, FIG. 2 is a flowchart showing a stereoscopic image generating process in the embodiment, and FIG. FIGS. 4 and 5 are diagrams illustrating a change in data, and FIGS.

As shown in FIG. 1, the three-dimensional image generating apparatus for stereoscopic viewing according to the present embodiment is roughly divided into a control unit 10 for comprehensively controlling each unit and transmitting three-dimensional model data of a display object. , A geometry engine unit 11 for performing coordinate calculation and the like, a raster engine unit 12 for generating raster data for left and right display, a display unit 13 for a left eye, and a display 14 for a right eye.

The three-dimensional model data sent from the control unit 10 is data representing a three-dimensional display object numerically. The geometry engine unit 11 includes a modeling conversion processing unit 15 that performs modeling conversion, a perspective projection conversion processing unit 16 that performs perspective projection conversion, and a clipping processing unit 17 that performs clipping processing. The modeling conversion is a process of converting a coordinate system of three-dimensional model data into an object coordinate system (absolute coordinate system). Perspective projection transformation is a process of fixing a viewpoint and projecting an object based on the position and direction of the viewpoint, and is a process of transforming an object coordinate system into a visual field coordinate system.

Conventionally, since the viewpoint positions of the right and left eyes are different, two perspective projection transformations for the left eye and the right eye are performed as described above. One perspective projection transformation is performed using the position as the viewpoint. This is based on the fact that one image recognized when stereoscopically viewing the left and right images is similar to an image obtained by placing the viewpoint at the center of the left and right eyes. Also,
The clipping process is a process of designating a display area on a display and removing data outside the display area.

The raster engine unit 12 performs a hidden surface erasing process unit 18 for performing a hidden surface erasing process, a shading processing unit 19 for performing a shading process, and performs a process of shifting the obtained raster data for left and right display. The hidden buffer erasing unit 18 is connected to a Z buffer 18a used for hidden surface erasing processing. The hidden surface erasing process is a process of erasing a surface (hidden surface) that is actually hidden and cannot be seen in order to obtain an image close to the real thing with a strong sense of reality. Is removed, and only the portion visible from the front is left displayed.

In this embodiment, a so-called Z buffer method is used as a technique for erasing a hidden surface. This is achieved by providing a memory (the Z buffer 18a) for storing the distance in the Z-axis direction (depth direction) for each pixel (pixel), and comparing new and old distance data when newly writing pixel data, This is a method of leaving the pixel data closer to. The shading process calculates how much light that hits the model is reflected in a specific direction when displaying a model of a three-dimensional object, and creates a shadow on the surface according to the direction and direction of the surface. This is the process of attaching. Performing this shading process further clarifies the interrelationship between objects.
Reality increases. A three-dimensional visual effect is realized by such hidden surface elimination processing and shading processing, and the image data (raster data) obtained by these processings has a three-dimensional effect.

The details of the right and left shift processing will be described later in detail, but the object is determined in accordance with the difference between the tentatively set viewpoint (the center of the left and right eyes in this embodiment) and the viewpoint of each of the right and left eyes. Is shifted in accordance with the depth value (Z value) of the raster data, and thereby an image for the left eye and an image for the right eye are generated.

The left and right display sections 13 and 14 are respectively composed of frame buffers 21 and 22 for storing data obtained by the left and right shift processing, and displays 23 and 24 for displaying images. Frame buffer 2
Reference numerals 1 and 22 denote large-capacity memories for storing digital image data.
The pixel data can be written at the same time as the A / A conversion and display.

The coordinate transformation processing means is a perspective projection transformation processing section 16 and the three-dimensional effect realization processing means is a hidden surface erasing processing section 18.
The shading processing unit 19 and the left / right shift processing means are respectively constituted by a left / right shift processing unit 20.

Next, the process of generating an image by the present apparatus configured as described above will be described with reference to the flowchart shown in FIG. First, when three-dimensional model data 30 (see FIG. 3A) of a display object is sent from the control unit 10 to the modeling conversion processing unit 15 (S1), the modeling conversion processing unit 1
5 performs modeling transformation such as enlargement, reduction, rotation, and translation on the model data 30, calculates model data 31 (see FIG. 3B) in the object coordinate system, and converts this data into perspective projection transformation. It is sent to the processing unit 16 (S2).

Next, the perspective projection conversion processing unit 16 performs perspective projection conversion on the model data 31 based on a preset viewpoint position and direction, and obtains model data 32 (FIG. c) see)
This data is sent to the clipping processing unit 17 (S3).
At this time, as described above, conventionally, since the viewpoint positions of the left and right eyes are different, two perspective projection transformations for the left eye and the right eye are separately performed. One perspective projection transformation is performed with the center position as a viewpoint. For this reason, the amount of data processing for perspective projection conversion occupying much of the data processing time is reduced by about half.

Next, the clipping processing section 17 removes data outside the display area specified in advance, adjusts the model data 32 to the display size, and sends this data to the hidden surface erasing processing section 18 (S4). Next, the hidden surface elimination processing unit 18 performs a hidden surface elimination process by the Z-buffer method on the model data 32 subjected to the clipping process, and deletes the data 33 that is actually hidden and invisible.
(See FIG. 3D) and sends this data to the shading processing unit 19 (S5).

Next, the shading processing section 19 performs shading processing on the data 33 on which the hidden surface removal processing has been performed, and shades the data 34 according to the direction and direction of the surface (FIG. 3 ( e) is calculated, and this data is sent to the left / right shift processing unit 20 as raster data (S6). The model data 32 is given a three-dimensional effect sequentially through the hidden surface elimination process (S5) and the shading process (S6), and finally changes into real image data (raster data) 34 having a strong sense of reality. Will do.

The raster data 34 is shifted left and right by the processing unit 20.
, The left / right shift processing unit 20 performs the left / right shift processing on the raster data 34 in parallel for the left eye and the right eye, and outputs the image 35 for the left eye (see FIG. 3F) and the right eye. Image 36 (see FIG. 3 (g)) is generated (S7). That is, each pixel (pixel) data of the raster data 34 is converted into a depth value (Z value) in accordance with the difference between the tentatively set viewpoint (the center of the left and right eyes in this embodiment) and the left and right eyes. , That is, Z in the viewpoint coordinate system
Shift in proportion to the value in the axial direction. Thus, the larger the Z value, the larger the shift amount.

The actual shift amount is proportional to the distance between the viewpoint and the object, the size of the object, and the display size. For example, taking the case of generating an image for the left eye as an example, as shown in FIG. 4, when the ridge line A and the ridge line B are compared, the ridge line B has a larger Z value. The shift amount to the left indicated by the middle arrow increases. If this is actually shifted and displayed, as shown in FIGS. 5A and 5B, the ridge line B appears to be shifted leftward.

The image 35 for the left eye generated in step 7
And the image 36 for the right eye are stored in the corresponding frame buffers 21 and 22 (S8, S9), and displayed on the left and right displays 23, 24 (S10, S11). When this is viewed using a stereoscope or stereoscopic glasses, the object can be viewed stereoscopically.

Therefore, according to this embodiment, the perspective projection conversion processing unit 16, the clipping processing unit 17, the hidden surface elimination processing unit 18, and the shading processing unit 19 are shared for the left and right images. Although the amount of calculation is substantially reduced by half and the left and right shift processing unit 20 is added, the apparatus configuration is simplified as a whole, and the amount of calculation of the entire apparatus can be reduced correspondingly, thereby shortening the processing time.

In this embodiment, the hidden surface elimination process and the shading process are used as a method for producing a three-dimensional effect. However, the shading process is not limited to this, and other rendering processes, such as ray rendering, may be used. Tracing (ray tracing method) or the like may be used. Further, in the present embodiment, the left-eye image and the right-eye image are displayed on the left and right separate displays. However, one display may be used in a time-sharing manner, and other images different from each other may be displayed. Obviously, a presentation means capable of presentation may be used.

[0030]

As described above, according to the present invention, a series of processes from the coordinate conversion process for the three-dimensional model data of the display object to the three-dimensional effect realization process is shared for the left and right images. In addition, the apparatus configuration is simplified, the amount of calculation of the entire apparatus is reduced accordingly, and the processing time is shortened.

[Brief description of the drawings]

FIG. 1 is a functional block diagram of an embodiment of a stereoscopic three-dimensional image generating apparatus according to the present invention.

FIG. 2 is a flowchart illustrating a stereoscopic image generation process according to the embodiment.

FIG. 3 is an explanatory diagram showing a change in data after various processes using a cube as an example.

FIG. 4 is an explanatory diagram of a shift amount for obtaining a left-eye image in a left-right shift process.

5 is a diagram illustrating an image shifted according to the shift amount in FIG. 4;

FIG. 6 is a functional block diagram showing a data flow of a conventional stereoscopic three-dimensional image generating apparatus.

FIG. 7 is an explanatory diagram illustrating a state in which an object is viewed from left and right eyes.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Control part 15 Modeling conversion processing part 16 Perspective projection conversion processing part (coordinate conversion processing means) 17 Clipping processing part 18 Hidden surface elimination processing part (stereoscopic effect realization processing means) 19 Shading processing part (stereoscopic effect realization processing means) 20 right and left Shift processing unit (left and right shift processing means) 21, 22 Frame buffer 23, 24 Display

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) G06T 1/00 G06T 11/00-17/50 H04N 5/262-5/28 H04N 13/00-17 / 06

Claims (1)

(57) [Claims] 1. A stereoscopic three-dimensional image generating apparatus for generating an image for a left eye and an image for a right eye and displaying the images for the left and right eyes, respectively. a visual field coordinate conversion processing means for converting the visual field coordinate system placed the viewpoint center, the steric effect realized processing means for applying a process to achieve a three-dimensional visual effect on the processing result of the visual field coordinate conversion processing unit, the three-dimensional effect Pixel data that is the processing result of the realization processing means
Is proportional to the value in the Z-axis direction in the view coordinate system from the viewpoint.
The image for the left eye and the image for the right eye
DOO generates a lateral shift processing means and the three-dimensional image generating device for stereoscopic vision, characterized in that it comprises a.