JP3486578B2 - Image drawing method, image drawing apparatus, and storage medium - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a virtual image drawing method and a drawing apparatus for downloading a large amount of image data such as ray space theoretical data and presenting it to a user.

[0002]

2. Description of the Related Art Many techniques have been proposed for describing and describing a virtual space based on a photographed image, rather than based on a three-dimensional geometric shape. These are Image Based Rendering
It is called (hereinafter abbreviated as IBR), and is characterized in that it can represent a highly realistic virtual space that cannot be obtained from a method based on a three-dimensional geometric shape because it is based on a real image. .

An attempt to describe a virtual space based on the ray space theory, which is one of the IBR methods, has been proposed. For example, IEICE Transactions "Realization of Virtual Environment by Fusion of CG Model and Ray Space Data" (D-11, Vol. J80-D-
11 No. 11, pp3048-3057, November 1997), or "3
See Mutual conversion between hologram and ray space for three-dimensional integrated image communication (3D Image Conference).

The ray space theory will be described.

As shown in FIG. 1, the coordinate system OXY-
Install Z. A ray passing through a reference plane P (Z = z) perpendicular to the Z axis is represented by a position (x, y) where the ray crosses P and variables θ and φ indicating the direction of the ray. That is, one ray is uniquely determined by the five variables (x, y, z, θ, φ). If the function expressing the light intensity of this ray is defined as f, the ray group data in this space can be expressed by f (x, y, z, θ, φ). This five-dimensional space is called "ray space"
Call. More generally, the time variation t may be included, but it is omitted here.

Here, if the reference plane P is set to z = 0 and the parallax information in the vertical direction of the light beam, that is, the degree of freedom in the φ direction is omitted, the degree of freedom of the light beam is reduced to two dimensions (x, θ). Can be made. This x-θ two-dimensional space is a subspace of the ray space. Then, if a ray (Fig. 2) passing through a point (X, Z) in the real space is set as u = tan θ, in x-u space, as shown in Fig. 3,

[Equation 1] X = x + u · Z

Is mapped on the straight line. Shooting with a camera corresponds to an operation of receiving a light beam that passes through the lens focal point of the camera on an imaging surface and imaging its brightness and color. In other words, a group of light rays passing through one point in the real space, which is the focus position, is acquired as an image for the number of pixels. Here, since the degree of freedom in the φ direction is omitted and the behavior of light rays is considered only in the XZ plane, only pixels on a line segment that intersects the plane orthogonal to the Y axis in the image are considered. Become. In this way, light rays passing through one point can be collected by photographing an image, and data on one line segment in the x-u space can be acquired by one photographing.

If this photographing is performed many times by changing the viewpoint position (in this specification, unless otherwise specified, the viewpoint position includes both the viewpoint position and the line-of-sight direction), a ray group passing through a large number of points is obtained. Can be earned. N as shown in FIG.
When the real space is photographed using two cameras, the nth (n =
1, 2, ..., N) corresponding to the focal positions (X _n , Z _n ) of the cameras C _n , as shown in FIG.

[Equation 2] x + Z_nu = X_n You can enter the data on the straight line. like this
In addition, by shooting from a sufficient number of viewpoints,
The xu space can be densely filled with data.

Conversely, an observation image from a new arbitrary viewpoint position can be generated from the data in the xu space (FIG. 6) (FIG. 7). As shown in this figure, the observation image from the new viewpoint position E (X, Z) expressed in the form of eyes is
It can be generated by reading the data on the straight line of Expression 1 on the xu space from the xu space.

[0012]

The photographed image data such as the above-mentioned ray space data is normally used for each unit (for example,
Each object is compressed and stored in an external storage device or the like. Therefore, in order to draw such spatial data in the virtual space, it is necessary to download it to the main memory, decrypt it, and draw it on the main memory. On the other hand, the user cannot grasp the virtual space until the virtual images of all virtual objects to be drawn in the virtual space are displayed. Therefore, when there are a plurality of objects to be drawn, the user is required to download, decode, and draw all the spatial data of those objects.
You will not be able to grasp those virtual objects. That is, when a walkthrough experience is made in such a virtual space, the drawing device has a poor response.

This is the first problem associated with the prior art in handling spatial data such as ray space data.

The second problem related to the prior art is that real shot image data such as ray space data contains a large amount of data. Such data is usually in the form of a database,
It is usually stored away from the image processing apparatus. Therefore, in order for the image processing apparatus to develop the virtual image in the virtual space, it is necessary to download a large amount of spatial data to the image processing apparatus. I have to keep it. Although the communication speed of real-image data has improved recently due to its huge size, the turnaround time from when spatial data is requested until it can be drawn in the image processing device. The length of the is so unnoticed. Therefore, the inventors have come to recognize the necessity of not boring the user in the waiting time until the real image data can be used in the system for presenting such virtual space to the user. . That is, during this waiting time, a scene from an arbitrary viewpoint position cannot be obtained, but a billboard image (one image) with a short download time is substituted.

A third problem related to the prior art is that, in the case of providing a walkthrough system capable of freely traveling in a virtual space by using real image data such as ray space data, the memory capacity of the system is limited. Occurs when there is. That is, in order to deal with the first problem described above, it is proposed to divide the virtual space into a plurality of sub-spaces (for example, in a virtual museum, each exhibition room constitutes one sub-space). You can

That is, when it is detected that the user is approaching a certain exhibition room, the time required for the transfer process prior to the drawing process is shortened by pre-reading the spatial data of only the exhibition room. To do. Furthermore, when the user tries to leave the exhibition room (sub-space A), the spatial data for the next sub-space (for example, exhibition room B) is stored, and the spatial data of exhibition room A is stored until then. It is necessary to overwrite the existing storage area and store it. By doing so, even if the memory capacity is relatively small, it is possible to reproduce the sub virtual space of the exhibition room one after another at a speed close to real time.

By the way, this pre-reading is judged when the viewpoint position of the user approaches the target sub-space.
However, moving the viewpoint position of the user does not mean that the mouse or the like is used to guide the route with high accuracy, and therefore the user may be invited to the wrong route. That is, the viewpoint position of the user who is not in the prefetch start area is
If the system mistakenly detects that it is in the prefetch start area, the system starts prefetch. In particular, when the user's viewpoint position is moved near the prefetch start zone, this malfunction is likely to occur. For example, as shown in FIG. 8, when an operation such that the viewpoint position enters the pre-reading start zone from the exhibition room space and then returns to the exhibition room space again, the erroneous pre-reading operation is performed. Then, the large volume of space data for the exhibition space was purged (erased), and "returned" to the exhibition space again (this is a situation that occurred because the viewpoint position was erroneously detected. , There is no consciousness of returning), the system side needs to transfer the data of this exhibition space again. This is a wasteful operation in terms of time.

The present invention is directed to the second problem mentioned above.

The object of the present invention is, in principle, to draw the spatial data of the external memory by using at least two spatial data stored in the external memory and the other in the internal memory. An image drawing method and apparatus capable of drawing the spatial data stored in the memory are proposed.

[0020]

In order to achieve this object, a drawing method for drawing a virtual image at an arbitrary viewpoint position in a virtual space according to claim 1 is a method for drawing a virtual image at a first viewpoint position . 1 spatial data that has the first data format
And with the best spatial data to compose the billboard image
Storing certain first spatial data in an internal memory,
The second spatial data of the second format at the viewpoint position is stored in an external memory different from the internal memory, and the second memory is used to generate a virtual image at an arbitrary viewpoint position from the external memory. Space data is downloaded, a virtual image at the arbitrary viewpoint position is drawn based on the first space data in the internal memory while the download is not completed, and then downloaded to the internal memory after the download is completed. Drawing is performed based on the generated second space data.

The second spatial data that needs to be downloaded is a huge amount of spatial data, and it is expected that it will be difficult to make it resident in the internal memory. While such second spatial data is not downloaded, a virtual image is drawn based on the first spatial data in the internal memory, thereby eliminating the discomfort that the image is not displayed to the user and increasing the cost of the expensive internal image. The memory can be used efficiently.

[0022]

Further, as described in claim 2 , the first spatial data is VRML spatial data having a small capacity but inferior in definition and resolution, and the second spatial data is a large capacity but fine. It is ray space theoretical data that is excellent in degree and resolution.

According to a preferred aspect of the present invention, this rendering method provides a user with a virtual walkthrough environment in the virtual space.

The first spatial data also has a relatively large capacity. It is desirable to store such first spatial data in the external memory as well. Therefore, according to a preferred aspect of the present invention, the first spatial data is stored in the external memory, and the first spatial data is stored before the second spatial data is downloaded. It is configured to terminate the download of the above into the internal memory.

For example, in the walkthrough providing environment, the virtual space is composed of a plurality of subspaces. That is, the second spatial data is composed of plural units of spatial data.

Therefore, according to a preferred aspect of the present invention, spatial data of a plurality of images captured in advance from different viewpoint positions are stored in the external memory as second spatial data, and the user is moved. The viewpoint drawing position is detected, and the image drawing process at the moved viewpoint position and the download process of the second spatial data are performed in parallel. In this specification, the method of this is achieved first examples of the first embodiment.

According to another preferred aspect of the present invention, spatial data of a plurality of images previously captured from different viewpoint positions are stored in the external memory as second spatial data, and the user is moved. Detecting the viewpoint position of, the spatial data corresponding to the moved viewpoint position is downloaded from the external memory, and while the download is not completed, drawing is performed based on the first spatial data in the internal memory, and the download is completed. After that, drawing is performed based on the second space data corresponding to the viewpoint position after the movement downloaded to the internal memory. In the present specification, this method is, first
This is realized by the second example of the embodiment.

According to a preferred aspect of the present invention, the internal memory is at least the first spatial data and the second spatial data.
It has the capacity to store the spatial data of.

It should be noted that the above object of the present invention is not limited to the virtual space.
It is a drawing device that draws a virtual image at the desired viewpoint position.
Is the first spatial data at the first viewpoint position.
Has a first data format and composes a billboard image
Stores the first spatial data, which is the optimal spatial data for
Internal memory and a second memory at the first viewpoint position.
The internal memory for storing the second spatial data in the form of
External memory different from Mori and virtual at any viewpoint position
The second memory from the external memory to generate an image;
Download the spatial data of the above into the internal memory
Download means and the virtual image at the arbitrary viewpoint position,
While the download is not completed, the first in the internal memory
Drawing based on the spatial data of
Is the second space downloaded to the internal memory
To have a drawing means for drawing based on the data
It is also achieved by a characteristic image drawing device .

Further, the above-mentioned object is to realize an arbitrary view in the virtual space.
A drawing apparatus for drawing a virtual image at a point position, comprising:
VRML first spatial data at the viewpoint position of
Internal memory for storing and light at the first viewpoint position
To store the second spatial data in line space theory data format
External memory different from the internal memory, and any
In order to generate a virtual image at the viewpoint position, the external memo is used.
Download the second spatial data to the internal memory.
Download means to download and the arbitrary viewpoint position
The virtual image in
Drawing based on the first spatial data in the partial memory
After the download is completed, it will be downloaded to the internal memory.
Drawing means for drawing based on the second spatial data
Also achieved by an image drawing device characterized by having
Is made.

[0032]

DETAILED DESCRIPTION OF THE INVENTION Referring to the accompanying drawings,
An image drawing apparatus and an image drawing method according to an embodiment in which the present invention is applied to a walkthrough experience in a virtual space will be described in detail. These embodiments have ample memory space and data (r
ay space data (hereinafter, sometimes abbreviated as RSD), a walk-through system (first embodiment) having a main memory only for storing, and a small main memory device inside,
An embodiment (second embodiment) will be described in which the storage area is secured → the storage area is repeatedly released because there is no capacity to store all the spatial data.

FIG. 9 shows the configuration of the image processing system of the embodiment. The hardware configuration shown in FIG. 9 is that of a normal workstation. That is, the hardware configuration itself is no different from that of an ordinary workstation.

This system allows the user to CR the virtual space.
It is presented on T23. The user operates the mouse 28 to freely walk through the virtual space,
It is possible to operate (move, rotate, magnify, etc.) an object in the virtual space. That is, the object in the virtual space is converted into the ray space data based on the photographed image, and
Although stored in advance in Fig. 5, when the viewpoint position moves as it walks through, an image that can be observed at the moved viewpoint position is generated as described in Fig. 7, and the conventional CG data based on the geometric model is rendered. The image thus generated is combined and displayed on the CRT 23.

The RSD database 29 has a large capacity memory and stores the ray space data of the entire space. The billboard image database 31 also stores a plurality of billboard images. Here, the billboard image data is, for example, image data of an object observed from a certain viewpoint position, and the amount of data is extremely smaller than that of ray space data.

As mentioned above, if the transfer of ray space data from the database 29 is not in time, this billboard image is provided to the user instead.

Reference numeral 32 denotes a joystick, which instructs the user to move the viewpoint position.

FIG. 10 shows a virtual space formed by the first and second embodiments. Each of this virtual space is a sub virtual space,

Zone A, Zone B, Zone C, Zone D, Zone E

It has five zones: In FIG. 10, for convenience of explanation, only zone A and zone B are shown in detail. The boundary of each zone (sub virtual space) is shown to the user by a chain line. The moving path (walk-through path) of the user's viewpoint position is indicated by a thin solid line. In one zone, a rectangular "wall" representing a virtual exhibition room is indicated by a thick solid line. Each exhibition room has four entrances and exits. From here,
The user can virtually enter and exit each exhibition room.

<First Embodiment> FIG. 11 shows the arrangement of an image processing apparatus according to the first embodiment. The feature of the first embodiment is that when the preparation of the ray space data is not in time, for example, a billboard is installed at a position where the ray space data object is arranged in the virtual space, and an image is displayed on the billboard.
By pasting (billboard image) and presenting it to the user, a sense of discomfort due to a transfer delay (download delay) of the ray space data from the database 29 is prevented. This is because the billboard image has an overwhelmingly smaller data capacity than the ray space data, and therefore the transfer time is shorter than that of the ray space data transfer.

In FIG. 11, ray space data and billboard image data are stored in external databases 29 and 31. These databases are stored in predetermined areas (27A, 27B) in the main memory 27 via a communication interface (eg Ethernet). The drawing unit 40 draws the ray space data and the billboard image data stored in the main memory in the virtual space under the control of the CPU 20.

In the first embodiment, the CPU 20 stores the ray space data from the RS data DB (database) 29 in the memory area 27A and the billboard image data in the memory area 27.
Save to B. Whether or not the data can be stored in the memory is managed for each zone by using a table as shown in FIG.

In the first embodiment, the light space data is transferred to the main storage memory 27 according to the three transfer orders. The three examples are the first embodiment, the second embodiment and the third embodiment. As described below.

FIG. 13 is a flowchart of the control procedure according to the first embodiment. In the first embodiment, all billboard image data are processed in steps S10 to S14.
Then, after downloading and storing from the database 31 to the main memory 27B and decoding the image data, the walkthrough experience in the virtual space is enabled. The feature of the first embodiment is that the virtual image is presented to the user to give a walk-through experience (steps S16 to S24) and the light space data is transferred to the main memory 27A (steps S30 to S38). )
And are performed in parallel (however, they may be performed in series).

That is, when the billboard image transfer processing (including the decoding processing) in steps S10 to S14 is completed, the billboard image data "exists" for all zones in the table of FIG. Will be marked.

When step S14 is completed, walkthrough becomes possible. That is, the viewpoint position designated by the user with the joystick or the like is detected in step S18, and in step S20, ray space data close to the viewpoint position is selected.

Here, the ray space data close to the viewpoint position is the space data of the virtual object (including the sub virtual space) within a predetermined distance with respect to the position of the current viewpoint position in the three-dimensional space. To tell. Only the distance matters, and the user's line of sight does not matter. This is because an object in any direction can be approached by the user. In the example of the first embodiment, the distance may be determined in advance in relation to the size of the exhibition room.

When the ray space data corresponding to the viewpoint position does not yet exist in the memory 27, the billboard image data is substituted. That is, the latter is prioritized in the billboard and the ray space image. This is because the ray space data can generate a high-definition virtual image from an arbitrary viewpoint position based on image data from a specific viewpoint position. Therefore, if the ray space data exists in the main memory 27, a virtual image is generated according to the current viewpoint position in step S22 and presented on the CRT in step S24.

In parallel with the drawing and presentation of the virtual space by walk-through, the light space data is transferred in steps S30 to S38. That is, step S30
Then, the data transfer of the light space data is performed in units of one space. Here, the spatial data of one spatial unit is, for example,
It refers to a group of spatial data related to one zone or the like, such as FIG. When the data transfer for each unit is completed, an image is generated from the ray space data in step S34, it is marked in step S36 that the ray space data exists in the main memory, and in step S38, the next space Request to send ray space data to DB29.

In step S36, only the presence of ray space data is marked, and the corresponding billboard image is not erased. However, from the viewpoint of effective use of memory, as long as ray space data is available, The unused billboard image data may be removed from the main memory 27.

As described above, in the first example of the first embodiment, the billboard image is first downloaded to enable a walkthrough experience in the virtual space, and then the virtual image is drawn in the virtual space. And the ray space data transfer from the database are performed in parallel, and if the ray space data at the viewpoint position in real time does not exist in the main storage device, a virtual image is drawn using the billboard image data. If the required ray space data exists in the main storage device, a virtual image is drawn using the ray space data. As a result, at least a walkthrough experience with billboard images,
Enable early.

FIG. 14 shows the control procedure of the second embodiment. In the first embodiment, the light space data is transferred from the DB 29 to the main memory 27A in a predetermined order, but in the second embodiment, the light space of the space close to the current viewpoint position of the user. The data is selectively transferred from the database 29. This is because the closer the data is to the viewpoint position of the user, the more the drawing should be requested.

The control procedure of FIG. 13 and the control procedure of FIG. 14 are different only in that the latter has steps S26 and S28. That is, in step S26, the current viewpoint position of the user is acquired, and in step S28,
The light space data for one space close to the position is transferred.
The other steps are the same as in the first embodiment.

Further, in this example, the ray space data of the space close to the user's viewpoint position is selected and read, but the ray space data of the object closest to the viewpoint position is also read in one space. It is also possible.

In the second embodiment, the decoding of the ray space data was also performed immediately after the transfer of the ray space data from the database. That is, the ray space data of one space unit is decrypted along with the transfer and stored in the main memory. What takes time to process is the transfer of compressed ray space data and the decoding of the compressed data, except for the drawing of virtual images. Therefore, in the third embodiment, the ray space data is downloaded to the main memory at the same time as the billboard image is downloaded, and the ray space data is kept in the main memory as it is encoded. Decoding of the ray space data necessary for drawing at an arbitrary viewpoint position in real time is performed when the request is made.

FIG. 35 is a flow chart showing the control procedure of the third embodiment. If the flowchart of FIG. 35 and the flowchart of the second embodiment (FIG. 14) are compared and the same step numbers indicate the same processing, step S12 of the second embodiment is the same as that of the third embodiment. Step S13, step S20 of the second embodiment, step S21 of the third embodiment, step S28 of the second embodiment.
Is changed to step S29 in the third embodiment. That is, in step S13, the billboard image data is downloaded and decoded in all space units, and in the same step, the ray space data is also downloaded in all space units. Then, in step S29, only the ray space data of the space closest to the current user viewpoint position is decoded, and the data is used for virtual image generation in step S34.
6 → step S38 to step S16 → ... → step S24.

Thus, according to the third embodiment, although there is a disadvantage that the encoded ray space data has to be downloaded, it is possible to enjoy the walk-through experience in the virtual space by the billboard image at an early stage. It is possible to obtain the same effect as that obtained by the first and second embodiments. In addition, since the light space data is decoded only at the position close to the current viewpoint position, there is an effect that the virtual space at the viewpoint position in real time can be experienced with good response. Also, even if
Even if the decoding is not in time, at least the billboard image is presented, so that the real-time property is ensured.

In the third embodiment described above, it is described that the walkthrough cannot be performed until the pre-encoded ray space data is read into the main memory. You may read the digitized ray space data in parallel.

<Effects of First Embodiment> The first embodiment described above
According to an embodiment,

I: By making the billboard image data exist in the main memory first, even if the ray space does not exist in the DB, by presenting at least a part of the image to the user, the sense of discomfort can be eliminated. Even for a billboard image, the user can assume the characteristics of the virtual space by the image, so that the user can proceed to the next space if he / she can determine that it is unnecessary. II: The transfer of ray space data can take various forms. According to the method of the first embodiment, since the light space data is transferred in a predetermined order in parallel with the presentation of the virtual image, the walkthrough and the light space data can be simultaneously processed. There is. III: The method of the first embodiment does not always provide the data in the ray space which the user wants at the present moment. However, the method of the second embodiment presents a virtual image with image data in the space that the user actually wants. IV: According to the third embodiment, it is possible to achieve both the problem of wanting to have a walk-through experience in a virtual space at an early stage and the walk-through experience having excellent real-time properties.

<Second Embodiment> The first embodiment was effective when the main storage capacity was enormous. However, the ray space data has a huge capacity, and in many cases, the system memory (main memory) has no room. The second embodiment makes it possible to draw a virtual space using ray space data even with a small memory capacity. That is, the system of the second embodiment detects the partial virtual space desired by the user, and obtains the data of the partial (sub) virtual space by prefetching before entering the subspace. In the second embodiment, since the memory capacity is limited,
Once you enter one subspace and exit to another subspace,
The ray space data of the previous space is erased. On the other hand, the pre-reading by estimation causes the inefficiency on the contrary if the estimated space is erroneously identified, the ray space data secured in the memory is erroneously erased. In this regard, the second embodiment has a special device (described later).

FIG. 15 shows the hardware configuration of the image processing apparatus according to the second embodiment. The difference from the first embodiment is that the capacity of the main memory 27 is reduced, so that the memory area for storing the light space data is divided into two units of capacity (called bank B1 and bank B2). It is that you are.

A characteristic of the second embodiment is that various information is embedded in advance in each zone of the virtual space. That is, the virtual space is a plane direction,

Intermediate zone,

Transition zone,

Display target zone

It is divided into three types of zones.
The display target zone is a virtual zone set for the first purpose of displaying a virtual image based on ray space data.
As can be seen from the example in the figure, the size is set according to the size of the exhibition room, which is the main purpose. In the example of FIG. 16, both zone A and zone B are “display target zones”. The user can freely move inside the display target zone, and the present system generates and displays a virtual image that matches the user's moved viewpoint position. Outside the display target zone, a "transition zone" and an "intermediate zone" are provided, which represent a movement route to the display target zone and other display target zones. The “transition zone” is a band-shaped zone formed with a substantially same width in the peripheral portion of the display target zone that is currently staying. Further, the intermediate zone is a moving area formed as a "passage" formed between the plurality of display target zones.

In the example of FIG. 16, the transition zone is a table.
Outside the target zone A, T_AC, T _AB, T_AD, T_AEIs provided
Outside the display target zone, T_BC, T_BA, T_BDSet up
It has been burned. For example, transition zone T_ACIs the display target
To control the transition between display area A and display target zone C
Information is embedded. Naturally, the transition is 2
Exists in the direction. That is, the transition to enter the display target zone
And a transition to move out of the display target zone
It

Each zone has an attribute value indicating the attribute of that zone, as shown in FIG. Furthermore, in addition to the attribute value, that zone is the display target zone (attribute value = 0)
, The “necessary image ID” (hereinafter, RQD-ID) indicating an image required for drawing display in the zone itself.
Abbreviated) field.

The transition zone handles the transition between the two display target zones as described above. For this reason, when the viewpoint position of the user is in the transition zone, the direction of change of the viewpoint position has one of two directions. In order to show the case where the transition zone transitions from the inner display target zone to another display target zone, the image of the display target zone outside the transition target zone is requested (that is, the display target zone outside is moved). Request of pre-reading in anticipation of that)
"Outside requested image data ID" (hereinafter referred to as EX
In the T-DMND-ID field, the ID of the ray space data in the display target zone to be moved is stored. Also, in order to show the case where the transition zone concerned transitions from the other outer display target zone to the inner display target zone, an image of the inner display target zone is requested (that is, to the inner display target zone). In order to indicate that the pre-reading request is expected to move), the “inside requested image data ID” (hereinafter abbreviated as INT-DMND-ID) field has a light beam in the display target zone to be moved. Stores the spatial data ID. Here, the “ID” is an identifier that designates a set of ray space data of one unit, as in the first embodiment.

Specifically, in the example of FIG. 16, the transition zone
Since the T _AC exists between the display target zone A and the display target zone C, this transition zone T _AC may enter the transition target zone T _AC for the purpose of entering the inner display target zone A. , There is a case where the transition zone T _AC has been entered for the purpose of advancing to the outside display target zone C. In the former case, the ray space image data A is requested in advance as INT-DMND-ID. And in the latter case, EX
The light space image data C is requested as a T-DMND-ID by prefetching.

Outside the transition zone, in the example of FIG.
An "intermediate zone" designated as X is provided. The intermediate zone can be moved without prefetching when moving from the display target zone to the display target zone.

The maximum purpose of the transition zone is to realize the look-ahead of the ray space data, which is required as the capacity of the memory 27 is reduced. In addition, if the memory is made smaller, the buffer that stores unnecessary ray space data must be released earlier (“first release”), but the purpose of the intermediate zone is to release the first release by mistake. In addition, the unnecessary trouble of downloading the lost ray space data from the DB 29 again is prevented. That is, as will be described later, even if the joystick or the like is erroneously operated and it is therefore erroneously determined to move out of the display target zone, in the second embodiment, the buffer (storage area in the memory bank) is immediately output.
To the other free memory bank without releasing
It stores the ray space data indicated by T-DMND-ID. By doing so, even when returning to the display target zone again in the example of FIG. 8, it is not necessary to download because the ray space data of the display target zone is stored in the memory bank.

FIG. 18 shows an example of zone attribute information embedded in various zones around the display target zone A.

With reference to FIG. 19, the characteristic control of the second embodiment in the process in which the viewpoint position of the user moves from the intermediate zone to the transition zone to the display target zone will be described. The image ID embedded in the transition zone in this example is A, where the ID (= INT-DMND-ID) of the spatial data targeted for prefetching when moving from the intermediate zone to the transition zone is A,
The ID (= EXT-DMND-ID) of the spatial data that is the prefetch start target when moving from the display target zone to the transition zone is B
Is. That is, when the transition is made from the intermediate zone to the transition zone, the INT-DMND-ID in the zone attribute information is read, and knowing that the spatial data in the subsequent display target zone is A, DB29 of the spatial data Start downloading from (for example) to bank B ₁ . Spatial data A is
Since it includes the entire ray space data of the display target zone A, pre-reading is effective because the ray space can be used immediately when the display target zone A is actually reached. Next, when moving from the transition zone to the display target zone, the RQD-
Since the ID is A, the space data A is stored in the memory area of the main memory 27 (for example, in the bank by downloading as described above).
B ₁ ) Confirm that it is stored in. If the download is not completed, you will wait in this display target zone.

According to FIG. 20, the viewpoint position of the user moves from the display target zone to the transition zone to the intermediate zone,
That is, the characteristic control of the second embodiment in the process of moving to another display target zone will be described.

When the transition is made from the display target zone to the transition zone, the EXT-DMND-ID in the zone attribute information is read out, and the spatial data of the display target zone adjacent to the display target zone A that has been staying until then is B. Know that. Then, the download of the spatial data from the DB 29 is started. Here, since the spatial data A is already stored in the bank B ₁ , the download destination of the spatial data B is the bank B ₂ . That is, the spatial data A in the bank B ₁ is saved as it is.

In the second embodiment, while remaining in the same transition zone, the spatial data for the display target zone below the transition zone is held. With this hold, even if the user returns to the display target zone again, bank B ₁
Since the spatial data A inside can be used as it is, the re-download of the ray space data A is prevented. Also,
Since the pre-reading of the ray space data B for the next display target zone has already started, it is expected that the ray space B can be immediately drawn when the display target zone B is reached.

In the second embodiment, the ray space data of the previous display target zone can be held while remaining in the transition zone, and is limited to staying in the transition zone for a predetermined time. This time should be variable or preset according to the capacity of the light space of 1 unit, the user's preference, the size of the virtual space, but for convenience of explanation, in this second embodiment, For example, it is set to 5 seconds. That is, in the example of FIG. 21, after moving from the display target zone A to the transition zone, it returns to the display target zone, shifts to the transition zone again, and returns to the display target zone,
Further, although the operation of moving to the transition zone is performed, in this operation, the ray space data A is held because all the time spent in the transition zone was less than 5 seconds. is there.

On the other hand, in the example of FIG. 22, 5 is set in the transition zone.
Since it stayed for a second, the data A in the bank B ₁ was purged (invalid) and its buffer was released even though it stayed in the transition zone.

As shown in FIG. 21, while the viewpoint position of the user remains in the transition zone, the user can operate the mouse or the joystick to move the peripheral portion of the display target zone, though it is inside the display target zone. This is because if it is done, the user may erroneously enter the transition zone, resulting in erroneous recognition for the user.
However, staying in the transition zone for more than 5 seconds means
Since it is presumed that the user intends to leave the display target zone below, the ray space data of the zone stored in the buffer may be discarded.

Next, the control procedure of the second embodiment will be described with reference to the flow chart and the like. The 23rd
FIGS. 26 to 26 explain various registers used in this control procedure, and the actual control procedure is shown in FIG. 27 and subsequent figures.

FIG. 27 shows the main routine of the control procedure of the second embodiment.

That is, in step S100, the billboard image is downloaded from the billboard image DB 31. In the second embodiment, in principle, a virtual image based on ray space data is displayed in a display target zone such as an exhibition room. However, as described above, the bank capacity for storing ray space in the main memory is Since the number is small, the light space data is preread each time the display target zone is approached. For this,
In some cases, the ray space data may not be complete when the user enters the display target zone. The billboard image is displayed as an alternative image in such cases.

If all of the billboard images are downloaded to the bank B ₃ area of the memory 27 in step S100, the user is allowed to walk through in step S102 and subsequent steps.

In step S102, it is determined whether the user has operated the joystick or the like to move the virtual viewpoint position. If the viewpoint position has moved, it is determined in step S104 whether the movement is beyond the zone. If the movement is not across the zones, the process proceeds to step S116 to generate and display a virtual image at the viewpoint position. In this case, when the ray space data does not exist, the billboard image is displayed, and when the ray space data exists, the ray space data is converted into a virtual image and displayed. FIG. 28 shows a case where a virtual image based on ray space data is displayed and a case where a billboard image is displayed in correspondence with the viewpoint position.
The billboard image is the same as the first embodiment and the second embodiment.
In the embodiment, VRML (Virtual Reality Modeling Lang) is used.
uage). The advantage of displaying the billboard image is that when the user walks through the virtual space, so-called browsing is often performed on the target subspace, and in the case of such browsing, a high-definition image based on the ray space data is displayed. Rather, the billboard image is sufficient to achieve the purpose.

If the zone is changed by the user's viewpoint position movement, the process proceeds to step S104, and in step S106, the attribute value of the display target zone stored in the register CR-Z (see FIG. 21) is set. , Save to register PR-Z. In step S108, the zone attribute information (FIG. 17) of the zone is read and the attribute value is registered.
Hold on CR-Z. In step S112, the register PR-Z
The zone change is detected by comparing the attribute value of the previous zone of the above with the attribute value of the current zone in the register CR-Z.
Here, the zone change can be recognized as a change in the attribute value,
In the second embodiment,

2 → 1 (intermediate zone → transition zone),

1 → 0 (transition zone → display target zone)

0 → 1 (display target zone → transition zone)

1 → 2 (transition zone → intermediate zone)

There are four possible changes. Therefore, in step S114, processing according to these changes is performed.

<Intermediate Zone → Transition Zone> When moving from the intermediate zone to the transition zone, it is often expected that the user will move from the transition zone to the display target zone. On the other hand, in the second embodiment, as will be described later, the ray space data of the display target zone, which is the target of the user's experience request, transits to the transition zone following the previous display target zone (0 → 0 in FIG. 31). It should be prefetched in (1 move). Therefore, in step S200, it is confirmed which side of the memory bank B ₁ or B ₂ the ray space data having the INT-DMND-ID which is the attribute information of this transition zone is stored. This confirmation is performed by selecting one of the registers F _B1 and F _B2 which has the value 1 (the data in the bank is valid), and the bank B _X whose value is 1.
The value of the register ID _BX corresponding to can be used to check in which memory bank the ray space data is stored. If the ray space has already been downloaded into the bank, the control procedure of FIG. 29 is RETURNed to return to the main routine.

If the ray space data has not been downloaded, it is determined in step S202 whether or not it is currently being downloaded. This judgment is made by the register COM that manages the state of the communication interface 24 (FIG. 15).
This is done by examining the value of (see FIG. 26). CO
If M = 1, it is determined that the ray space data is being downloaded to either bank at present, and the routine is returned to the main routine. In step S202, the end of download is not waited for. This is because the download may have been completed before moving from this transition zone to the next display target zone. To check whether this download is in progress, check the flag F _B1.
It is even better to confirm by judging whether or not the value of F _B2 is 3.

If it has not been downloaded, the data is downloaded (prefetched) from the database DB 29 in step S204 and thereafter. That is, in step S204,
Find an empty memory bank. An empty memory bank is a memory bank in which the value of register F _B (FIG. 23) is 0.
When such a bank is found, the bank number is stored in the work register WK (= 0 or 1). In step S206, the value of the flag F _WK of the bank B _WK is set to the value 3 indicating that downloading is in progress. Then, in step S208, a transfer request for download is issued to the ray space DB 29. Then, the value of the register of the communication interface 24 is set to COM = 1 so as to indicate the download.

Thus, when the transition zone is entered from the intermediate zone, the storage state of the ray space data of the display target zone which will be further entered is confirmed, and if it is not stored, the download is performed. Start pre-reading of ray space data.

If NO is determined in step S200 (the required ray space data does not exist in the memory bank), it is determined in step S202 whether the data is being downloaded, and Regardless of the judgment result, from the control procedure of FIG. 29 to step S1 of FIG.
However, in step S116, since the virtual image is drawn with the spatial data at the moved viewpoint position, if the ray space data exists, the drawing with the ray space data has finished downloading. If not, the billboard image will be displayed as an alternative.

<Transition zone → Display target zone> FIG. 30 shows a control procedure when the transition zone is changed to the display target zone. In addition to the normal movement of transition zone → transition zone → display zone, transition zone → transition zone moves to display zone → transition zone, as shown in FIG. 21, from the transition zone. This includes cases such as returning to the display target zone. In any case,
Either the required spatial data already exists in the memory bank or it is being downloaded into that memory bank. Step S250
If the determination is NO, the control has an error, and the process ends. This determination is made by referring to the value corresponding to the required image ID (RQD-ID) in the attribute information (FIG. 17) of the display target zone and searching the table in FIG. That is, when entering the display target zone A, if B _A = 1 then the ray space data A is in the bank B ₁ , and if B _A = 2 then the ray space data A is in the bank.
Stored in B ₂ .

On the other hand, YES in step S250, that is,
If the necessary ray space data already exists in the memory bank, or if the data is being downloaded, it is checked in step S252 whether the value of the timer TMR is zero. That is, since the timer TMR is activated for 5 seconds as described above when moving from the display target zone to the transition zone, it is necessary to reset the timer TMR when returning to the display target zone again. . Therefore, in step S252, it is checked whether or not the monitoring timer TMR for 5 seconds is activated, and if it is activated, step S252
Reset at 254.

At steps S256 and S258, the ray space data once marked "gray" is restored as "valid" data. Regarding the processing in steps S256 and S258,
This will be performed in connection with the description of step S290 and subsequent steps in FIG.

Thus, in the display target zone, the user can experience the virtual space based on the ray space data.

<End of Download> The end of download is interrupted by this operating procedure by the operating system. When this interrupt is detected,
The control procedure of FIG. 34 is started.

In step S400 of FIG. 34, the state of the communication interface 24 is set to the idle state (COM = 0). In step S402, the memory bank in which the data is stored by the download is checked. That is, a bank with F _B = 3 is searched for and the bank number is saved in the work register WK. In step S404, the value of the register F _WK of the bank is set to "1" to indicate that the data is valid. Further, step S40
In _No. 6, in order to identify the data stored in the bank B _WK , the value of ID _WK is set to the ray space data identifier (A, B, C).
...). Further, in step S408, a value indicating the identifier of the downloaded ray space data is set in the register B (FIG. 24) indicating the storage destination of the space data.

Thus, the registers F _B1 , F _B2 , ID _B1 , I
By using D _B2 , B _A, etc., it becomes possible to arbitrarily check the location of the bank in which the ray space data is effectively stored.

<Display target zone → Transition zone> Third control procedure when moving from the display target zone to the transition zone
Shown in Figure 1.

That is, in step S280, the timer TMR
To start. Whether or not the timer TMR times out (the value of TMR reaches a predetermined value) is monitored by the control procedure of FIG.

In step S282 and thereafter, preparations for downloading the ray space data for the next display target zone (adjacent display target zone) are made. That is, step S282
Then, in order to search for an empty memory bank, a bank in which the value of the register F _B is 0 is searched, and the bank number is stored in the work register WK. In step S284, this memory bank B _WK is marked as being downloaded (F _WK = 3). Then, in step S282, the interface 24 is instructed to start downloading. In step S288, the state of the interface 24 is marked as downloading (COM =
3) Do.

Further, in step S290 and subsequent steps, the ray space data used for the drawing purpose in the previous display target zone (the display target zone in which the user was staying until then) is marked as "gray". As mentioned above, when moving from the display target zone to the transition zone, it is likely to move to another display target zone, so the ray space data used in the previous display target zone may be unnecessary. It is highly likely. However, in this second embodiment, the ray space data is held in consideration of the erroneous operation of the joystick, as described with reference to FIGS. 21 and 22. The ray space data held in the memory bank may be erased and is therefore referred to in this embodiment as being in the "grey" state. The light-space data in the "gray" state is erased in step S302 of FIG. 32, which is a control procedure of 1 → 2 movement.

In step S290, the transition zone
From the value of INT-DMND-ID, the identifier of the ray space data used for the previous display target zone is known, and this value is stored in the work register WK. In step S292, the register B that holds the storage destination of the image is stored. With reference to FIG. 24, the number of the memory bank in which the ray space data is stored is known, and the value is stored in the work register WK. Then, in step S294, F _WK = 2 is set in order to mark the state of this memory bank as “gray”.

Thus, in the control procedure of FIG. 31, by pre-reading the light space data for the next display target zone, and setting the light space data used until then into the "grey" state, It was possible to revive at any time.

If the user again performs an operation to return to the original display target zone, the operation is detected as a transition from the transition zone to the display target zone, and the third zone is displayed.
0 is processed by step S256. That is, the bank in the gray state is searched for in step S256, and the state value is set to F _B = 1 in step S258.

[0113] In step S286, the download has started, so that the light space data for the next display target zone is marked valid (F _B = 1) on the bank in due course, i.e., effective image A state occurs in which the data is stored in both of the two memory banks (B1 and B2), but in the second embodiment, since the image drawing is performed according to the value of the register B in FIG. Do not confuse ray space data.

<Transition Zone → Intermediate Zone> When moving from the transition zone to the intermediate zone, the control procedure of FIG. 32 is executed.

That is, in step S300, in order to purge the ray space data in the gray state, the bank storing the ray space data is searched. That is, in step S300, the bank with F _B = 2 is checked, the bank number is stored in the work register WK, and the state value of the register F _WK of that bank is set to 0 indicating that the data is invalid. Further, in step S304, the corresponding register ID _B (FIG. 23) and register B (FIG. 24) values are reset so that the invalidation of the data is reflected.

<Time-out Occurrence> The control procedure when the 5-second timer TMR times out will be described with reference to FIG. This timer TMR is effective only when the user viewpoint position is within the transition zone.

In step S500, the timer TMR is reset. In step S502, a bank that stores the ray space data in the "gray" state is searched for, and the bank number is stored in the work register WK. Step S
At 504, the value of the status register F _WK of the bank of that number is set to 0 (data invalid). In step S506, the associated register ID _B (FIG. 23) and register B (FIG. 24) values are reset to reflect the invalidation of the data.

Thus, if the user stays in the transition zone for a predetermined time or more, it is presumed that the user has a clear intention to leave the original display target zone, and the ray space data in the gray state is invalidated. That is, the buffer is automatically released on behalf of the user.

The second embodiment can be variously modified.

I: For example, in the second embodiment, a zone surrounding one display target zone is provided with only two double zones, that is, a transition zone and an intermediate zone, but the number is two. Not limited to one. For example, it is proposed to provide two upper transition zones and two lower transition zones. That is, in the second embodiment, the look-ahead of the ray space data is performed when the process proceeds to the next display target zone (display target zone → transition zone). However, the read-ahead was also performed when going from the intermediate zone to the display target zone, but since this is the read-ahead that starts in the transition zone of the layer next to the display target zone, the display target is immediately displayed from the transition zone. It will be moved to the zone, and its effectiveness is poor. Therefore, as described above, a transition zone of two layers is provided, in the transition zone of the upper layer, pre-reading when entering the display target zone is performed, and in the transition zone of the lower layer, the display target zone is changed to another display target zone. Try to look ahead when proceeding to. In this case, the intermediate zone becomes unnecessary. II: In the second embodiment, for example, the display target zone
(A) → Transition zone from A to B → Intermediate zone → Transition zone from C → Display target zone C, in the transition zone from A to B, ray space data for display target zone B Although the pre-reading is performed, the pre-reading does not become an efficient pre-reading because it is moved to the display target zone C in the end. In preparation for such a case, it is possible to prevent the prefetching inefficiency by subdividing all the intermediate zones in correspondence with the display target zones.

III: In the above embodiment, the light space data is described as an example, but the present invention is not limited to this.
The present invention is also applicable to spatial data that requires a certain amount of time for data transfer, that is, any spatial data that requires a data transfer time that hinders real-time processing. Therefore, according to the present invention, between the main memory and the DB,
It is not applied only to the system connected by the communication line, and whether or not the process of the present invention is necessary should be judged according to the degree of real-time requirement of the application. Therefore, in some cases, the present invention can be applied to a system in which the main memory and the database DB are connected by a parallel bus.

IV: In the second embodiment, the light space data in the gray area is erased when it stays in the transition zone for a predetermined time. However, the user further performs a predetermined keyboard operation. (Or, for example, the 36th
The erase operation may be started by an operation on a predetermined icon as shown in the figure). V: In the second embodiment, the ray space data is encoded in the database 29 and is decoded each time it is downloaded from the database. However, as described with reference to the third example of the first embodiment, while the decoding process of the encoded spatial data requires time, the encoded spatial data does not occupy a large memory capacity. That is, depending on the memory capacity of the main memory installed in the system, there is a possibility that there will be room for storing all the encoded ray space data. Therefore, when the main memory 27 has room, a modification similar to the third embodiment is applied to the second embodiment, that is, all the ray space data is downloaded to the memory 27. We propose a modification that decodes only the ray space data at the user viewpoint position that has moved in real time. In this modification, a processor or task dedicated to the decryption process is separately provided from the second embodiment, and further, the download operation of the second embodiment is modified so as to correspond to the decryption process. That is, whether or not downloading of flags (COM) is changed to whether flag or during the decoding process, the data in the bank is effective whether the flag (F _B of FIG. 23) is decoded Is set as a flag indicating whether or not Then, the modification is made so that the light space data of all the display target zones are downloaded together with the billboard image data in step S100 (FIG. 27). Then, the pre-reading from the database of the light space data when entering the new display target zone is changed to the operation of preceding the process of decoding the encoded data.

With such a modification, the real-time processing is further improved as compared with the second embodiment.

[0124]

As described above, according to the present invention, at least one of the spatial data is stored in the external memory in consideration of the capacity of the spatial data, and is downloaded as needed. However, during downloading, the user can experience the virtual space by drawing a virtual image based on the spatial data of the one existing in the internal memory. That is, it is possible to make both the optimization of the memory capacity and the constant presentation of the virtual image compatible .

[Brief description of drawings]

FIG. 1 is a diagram illustrating a principle of generating ray space data.

FIG. 2 is a diagram illustrating data in a real space.

FIG. 3 is a diagram when the space of FIG. 2 is represented by ray space data.

FIG. 4 is a diagram illustrating a principle of generating real space data when there are a plurality of cameras.

FIG. 5 is a diagram for explaining the principle of generating ray space data when there are a plurality of cameras.

[FIG. 6] From ray space data when there are multiple cameras,
The figure explaining the principle which produces | generates ray space data (x + Zu = X) in arbitrary viewpoint positions.

FIG. 7 is a diagram illustrating the principle of reconstructing the real space from the arbitrary viewpoint of FIG.

FIG. 8 is a diagram for explaining an inconvenience that may occur in a walkthrough environment proposed by the inventor.

FIG. 9 is a diagram illustrating a configuration of a virtual space presentation device (virtual image drawing device) according to the first embodiment and the second embodiment.

FIG. 10 is a diagram illustrating a configuration of a virtual space in the first embodiment and the second embodiment.

FIG. 11 is a diagram illustrating a configuration of a main part of the device according to the first embodiment.

FIG. 12 is a diagram illustrating a configuration of a table that manages a download state of ray space data and billboard image data in the system of the first embodiment.

FIG. 13 is a flowchart showing a control procedure of a first example of the first embodiment.

FIG. 14 is a flowchart showing a control procedure of a second example of the first embodiment.

FIG. 15 is a block diagram illustrating a configuration of a second embodiment of the present invention.

FIG. 16 is a diagram illustrating a configuration example of a virtual space used in the second embodiment.

FIG. 17 is a diagram showing attribute information given to each zone in the virtual space in the second embodiment.

18 Zone A of FIG. 16 according to the attributes of FIG.
The figure explaining the attribute value given to.

FIG. 19 is a diagram schematically illustrating a main control operation performed in a process in which the user's viewpoint position moves from the intermediate zone to the transition zone to the display target zone in the second embodiment.

FIG. 20 is a diagram schematically illustrating a main control operation performed in a process in which a user's viewpoint position moves from a display target zone to a transition zone and further to an intermediate zone in the second embodiment.

FIG. 21 is a diagram schematically illustrating a control operation when the user's viewpoint position reciprocates between the display target zone and the transition zone in the second embodiment.

FIG. 22 is a diagram schematically illustrating a control operation when the viewpoint position of the user stays in the transition zone in the second embodiment.

FIG. 23 is a diagram illustrating various registers used in the control procedure of the second embodiment, in particular, a register that manages the state of the memory bank and a register that stores the identification of the image stored in the bank.

FIG. 24 is a diagram illustrating various registers used in the control procedure of the second embodiment, particularly registers that manage the relationship between the ray space data to be drawn in each display target zone and the storage destination of the data.

[FIG. 25] Various registers used in the control procedure of the second embodiment, in particular, a register PR-Z that stores the identification of the display target zone that the user was immediately before and a register CR that stores the identification of the current display target zone. The figure explaining -Z.

FIG. 26 is a diagram illustrating a register COM and a timer TMR used in the control procedure of the second embodiment.

FIG. 27 is a flowchart relating to the main routine of the control procedure of the second embodiment.

FIG. 28 is a diagram illustrating a relationship between a virtual image based on ray space data and a virtual image based on billboard image data in the second embodiment (similarly to the first embodiment).

FIG. 29 is a flowchart illustrating a part of the control procedure of the second embodiment.

FIG. 30 is a flowchart illustrating a part of the control procedure of the second embodiment.

FIG. 31 is a flowchart illustrating a part of the control procedure of the second embodiment.

FIG. 32 is a flowchart illustrating a part of the control procedure of the second embodiment.

FIG. 33 is a flowchart illustrating a part of the control procedure of the second embodiment.

FIG. 34 is a flowchart illustrating a part of the control procedure of the second embodiment.

FIG. 35 is a flowchart illustrating a part of a control procedure of a third example of the first embodiment.

FIG. 36 is a view for explaining the shape of an icon according to a modification of the second embodiment.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Daisuke Kotake, 6-145, Hanasaki-cho, Nishi-ku, Yokohama, Yokohama, Hanasaki Building, M Systems Co., Ltd. (56) Reference Japanese Patent Laid-Open No. 10-222699 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G06T 15/00-17/50 G06F 13/00

Claims (10)

(57) [Claims] 1. A drawing method for drawing a virtual image at an arbitrary viewpoint position in a virtual space , comprising: first space data at a first viewpoint position ,
Has a first data format and comprises a billboard image
The first spatial data that is the optimal spatial data for is stored in the internal memory, the second spatial data in the second format at the first viewpoint position is stored in an external memory different from the internal memory, In order to generate a virtual image at an arbitrary viewpoint position, the second spatial data is downloaded from the external memory, and the virtual image at the arbitrary viewpoint position is stored in the internal memory while the download is not completed. The image drawing method is characterized in that the drawing is performed based on the first spatial data, and after the download is completed, the drawing is performed based on the second spatial data downloaded to the internal memory. 2. A virtual image at an arbitrary viewpoint position in a virtual space
Is a rendering method for rendering the first space position in VRML format at the first viewpoint position.
Data in the internal memory, and is the light space theoretical data at the first viewpoint position.
The second spatial data that is different from the internal memory that is different from the internal memory.
In order to store in memory and generate a virtual image at any viewpoint position,
Download the second spatial data from the partial memory
And, a virtual image at the arbitrary viewpoint position, the download complete
If not, the first spatial data in the internal memory is used.
Draw based on the above, and after the download is complete, the internal memory
Based on the second spatial data downloaded to
An image drawing method characterized by drawing. 3. A process according to claim 1, characterized in that it provides a virtual walk-through environment to the user in the virtual space also
Is the image drawing method according to claim 2 . 4. The first spatial data is stored in the external memory, and the downloading of the first spatial data to the internal memory is terminated before the downloading of the second spatial data. Claim 1 to claim
Item 4. The image drawing method according to any one of Items 3 . 5. The external data is stored in the external memory as spatial data of a plurality of images captured in advance from a plurality of different viewpoint positions, the viewpoint position of the user to be moved is detected, and the viewpoint after the movement is performed. Image drawing processing at the position, and the second
The image drawing method according to any one of claims 1 to 4 , wherein the download processing of the spatial data is performed in parallel. 6. Spatial data of a plurality of images previously captured from different viewpoint positions are stored in the external memory as second spatial data, the viewpoint position of the user to be moved is detected, and the viewpoint after the move is performed. The spatial data corresponding to the position is downloaded from the external memory, and the first data in the internal memory is downloaded while the download is not completed.
The drawing on the basis of space data, after the download is complete the claims 1 to, characterized in that the drawing on the basis of the second space data corresponding to the viewpoint position after the movement has been downloaded into the internal memory Item 6. The image drawing method according to any one of Items 5 . Wherein said internal memory, at least, image drawing according to any one of claims 1 to 6, characterized in that it has a capacity to store the first spatial data and second spatial data Method. 8. A drawing device for drawing a virtual image at an arbitrary viewpoint position in a virtual space, comprising: first space data at a first viewpoint position ,
It has a data format of 1 and is used to compose a billboard image.
An internal memory for storing first spatial data that is optimum spatial data, and an external memory for storing the second spatial data of the second format at the first viewpoint position, which is different from the internal memory Downloading means for downloading the second spatial data from the external memory to the internal memory to generate a virtual image at an arbitrary viewpoint position, and downloading a virtual image at the arbitrary viewpoint position. Drawing means for drawing on the basis of the first space data in the internal memory while not completing, and drawing on the basis of the second space data downloaded to the internal memory after the completion of download. An image drawing device characterized by. 9. A virtual image at an arbitrary viewpoint position in a virtual space
And a first spatial data of VRML format at a first viewpoint position.
And an internal memory for storing data and a light space theoretical data format at the first viewpoint position.
The internal memory for storing second spatial data;
In order to generate virtual images at different viewpoints with different external memories,
The second spatial data from the partial memory to the internal memory
And the virtual image at the arbitrary viewpoint position are completely downloaded.
If not, the first spatial data in the internal memory is used.
Draw based on the above, and after the download is complete, the internal memory
Based on the second spatial data downloaded to
Image drawing characterized by comprising drawing means for drawing
Painting equipment. 10. The method according to any one of claims 1 to 7.
A computer system that realizes the image drawing method described above.
Computer device recording computer program
Recordable media.