JP2677233B2 - Computer graphics display method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [0001] BACKGROUND OF THE INVENTION The present invention relates to a model in graphic processing.
And 3D computer graphics.
Computer graphics table suitable for rafix
Regarding the indicating method. [0002] 2. Description of the Related Art Conventionally, three-dimensional computer graphics
IPSJ Transactions, Vol. 25, No. 6 (19
(84) As stated on page 948,
Each object model occupies a local area in the whole space,
Using the property that the areas of
We are trying to speed up the process. For example, what you want to display
A circumscribed rectangular parallelepiped is defined for the body model, and the model is created in space.
When performing the process of searching, only the inside of this circumscribed rectangular parallelepiped
It is a method of limiting. From the object model
Since it is not necessary to search far away areas,
It is possible to speed up the process. Further, a display speed increasing method utilizing the same property
As a method, in Japanese Patent Laid-Open No. 60-79477, on-screen
High-speed display by limiting the search to the rectangular area surrounding the object
Is becoming Further, JP-A-61-139890 discloses an object model.
The search range is limited by using the local existence of
This is a high-speed display method that utilizes the uniformity of the search processing. On the other hand, computer graphics 16-
3 (1982) pp. 9-18 (Computer Graph
ics, Vol.16, No.3 (1982) pp9-18)
In the system discussed in
It is possible to assign multiple models to
The operator created models with different levels of detail
The object on the screen and the size on the screen
Select and display the model with the level of detail required by the system.
Is possible. [0005] SUMMARY OF THE INVENTION Among the above prior arts,
In the high-speed display method using the local existence of the object model,
For example, if the object model is defined in a region far from the viewpoint,
Occupies a very small area on the screen
Details about the inside of a limited area, even if not
Since the object model is close enough,
Compared with the case, the processing time is reduced by a small percentage. one
On the other hand, in a system that can display models with different levels of detail,
The processing can be speeded up if the object model is far enough,
Models need to be created and assigned by the operator
Yes, to create multiple models for the same object,
The work man-hours of the data are large. It is an object of the present invention to reproduce a natural image at high speed.
To provide a way to display a computer graphic
You. [0007] [MEANS FOR SOLVING THE PROBLEMS] To achieve the above object
In the present invention,Depending on the moving speed of the model to be displayed,
Switch between detailed model and abbreviated modelDisplay equipment
Display in place. [0008] Further, the detailed model and the omitted model are
When switching and displaying on the display device, detailed
While changing the transmittance of each of the Dell and omitted models,
Switch from one to another. [0010] [0011][Action] Depending on the moving speed of the model to be displayed,Details
Switch between Dell and abbreviated models and display them on the display device.
As the model is shown, models with movement that is difficult to see are omitted.
The image can be displayed at high speed while realizing a natural image. Further, the detailed model and the omitted model are switched off.
When changing and displaying on the display device, the detailed model
While changing the transmittance of each of the
Since it is switched, the image does not change suddenly
There is little unnaturalness on the image. [0013] DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIG.
You. FIG. 1 is a diagram showing the outline of the present invention.
Viewpoint set in three-dimensional space as shown in 1 (a)
From 1, the ray 5 that passes through the screen 2 is traced to
The detailed model 3 to be the first three-dimensional model and the first
The two-dimensional screen
It explains how to display it on the screen. In addition, these
It is expressed as a numerical model on a computer.
Therefore, C that actually becomes the display as a result of the calculation
On the screen 8 of a two-dimensional display such as RT, liquid crystal, or EL
Detailed model display 6 (Fig. 1 (b)) or omitted
Display image such as display 7 ((Fig. 1 (c)) by model)
Can be obtained. FIG. 1 (d) shows a hardware for realizing the present invention.
It is a software configuration. The input device 1000 is a keyboard or
Inputting model information and display control information with devices such as bullets
Used to enter. The computer 1001 is according to this embodiment.
To execute input algorithms and control input / output devices
Input and definition of the detailed model, which is the first storage unit.
The essence part, the operation part that generates the abbreviated model and the abbreviated model
And a model selection part to display
Consists of Display controller 1002 is a computer
Analog signal for display from digital signal from
To display and control the display device 1003.
U. Then, by the display device 1003 which is the display unit
Images can be displayed on the screen. In addition,
The play device is a three-dimensional display using holography, etc.
Ray is fine. Here, the present invention will be described with reference to FIG.
The operation of each part of the embodiment when implemented by software
Will be described. Note that these may also depend on the hardware.
It is possible. First, step 101 is necessary for display.
This is a step of inputting detailed models and visual field information. example
For example, if the detailed model 3 has a rectangular parallelepiped shape with rounded corners
Is 8 spherical elements, 12 cylindrical elements and 6 as shown in FIG.
It is composed of 2 plane elements. And this detailed model
If we call it part 1, the structure of the graphic structure is shown in FIG.
It can be expressed in a book structure like this. Here, in this embodiment, as shown in FIG.
Some scenes consist of several objects
However, each object is also composed of several parts, and each part
An item is assumed to be composed of several graphic elements.
The hierarchical level of an object is called the object level, and so on.
Will be referred to as the component level and the graphic element level.
You. In this way, the input of the detailed model is the set of graphic elements
And define the shape of the 3D model on a computer.
You. On the other hand, the input of the visual field information means the viewpoint 1 or the viewpoint 1 in FIG.
To determine the position of screen 2 in three-dimensional space
And input with XYZ coordinate values, for example. Further screen
For screen size and orientation of the screen
Also enter. Other than that, a large number of pixels on the screen
Determine whether to display the object occupying the size in the detailed model
Therefore, enter the minimum size required to display the detailed model.
You. In short, in step 101, the object three-dimensional shape model is
Input detailed information as detailed model information and display it further
Enter the field of view information such as viewpoint and screen position for
This is a step of storing in the first storage unit. Step 102 is input in Step 101.
Based on the information of the detailed model created, the tree structure data of FIG.
Is the step of searching. In this embodiment, the tree structure of FIG.
Generating an abbreviated model at the part level in the build
Then, the tree structure in the same figure is searched for, for example, in the case of the component 1.
As described above, the detection at the component level is performed. Step 103 is the input detailed model.
Algorithm to generate an abbreviated model for
Up. Here, the detailed model is shown in FIGS. 3 and 4.
It shall be defined by a set of such graphic elements. So
As an abbreviated model, the circumscribed rectangular parallelepiped of the detailed model
Make a call. To generate this circumscribed rectangular parallelepiped,
As shown in 5, when the detailed model is projected on the XYZ axes,
The maximum / minimum value can be obtained. Projected on the X-axis in the figure
When the maximum value is x_max, The minimum value is x_minAnd the same below
Like y_max, Y_min, Z_max, Z_minSeeking. these
6 planes as shown in Fig. 6 from the maximum and minimum values
Formula, X = x_max, X = x_min, Y = y_max, Y = y_min, Z
= Z_max, Z = z_minGenerate Of these six planes
A three-dimensional model composed of equations is called an abbreviated model
And allocate. The detailed model entered is shown in Fig. 3.
It consists of a total of 26 graphic elements.
Each shape element has parameters such as radius and length. one
On the other hand, in the generated abbreviated model, circumscribing as in this embodiment
In case of rectangular parallelepiped, the above 6 plane equations are specified.
It can be described with 6 parameters. Therefore this step
Then, with the calculation means that reduces the number of parameters of the detailed model
is there. In addition, the spherical element and the cylindrical element that match the detailed model
Since such a quadric surface is not included in this abbreviated model,
It is a means of reducing the number of dimensions of Dell. Also, the data structure
The structure changes the tree structure shown in FIG. 4 as shown in FIG. here
The detailed model 3 is a set of 26 graphic elements in FIG.
The omitted model 4 is one circumscribed rectangular parallelepiped shown in FIG.
It is. That is, for the same part,
Assign two Dell models. Step 104 is for each pixel on the screen 2.
About repeating steps 105 to 108
I taste. Screen 2 is as shown in Figure 1.
It has m × n pixels and is usually a table of the display 1003.
Match the indicated resolution. Therefore, m up to step 108
× n times will be repeated. Step 105 is for the ray 5 in FIG.
This is the step of determining the equation. According to step 101
Field of view information has been entered, the viewpoint position and screen
The position and each pixel position are known. The ray is the viewpoint position P
_VAnd one pixel position P on the screen_SIs a straight line connecting
, P_V, P_SPosition vector of P_V, P_SThen t
As a parameter, t (P_S−P_V) Can be represented as
it can. P_VPosition is fixed, but P_SIs the position
Take m × n positions on the lean. In this way, m
Xn ray equations can be determined. Step 106 corresponds to step 103
For each generated omission model, from step 107
It is shown that steps up to step 108 are repeated. FIG.
Usually, there are multiple abbreviated models generated, as shown in.
For example, in addition to omitted model 4, omitted model A and omitted
Model B exists. In this step,
And for one ray 5 determined in
All the abbreviated models are detected from the tree structure in Fig. 7 and the
Repeat processing of steps 107 and 108. In step 107, the rays 5 are omitted models.
Is a means of determining whether or not there is an intersection. Ray of light
The equation is the linear equation determined in step 105,
The model is described by the equation of 6 planes as shown in FIG.
ing. Therefore, the determination of the intersection is an intersection question of the straight line and the plane.
It can be obtained as a subject. The light beam being processed is
When passing through the inner area of Dell's six planes, the intersection
Judge that there was. In step 108, the intersection point is
The step to display the abbreviated model when it is detected.
You. The fact that the intersection is detected means that the ray being processed is
It is said that the image of the omitted model is also projected on the clean 2
That is. So one pixel on the screen where the ray passes
Will display the abbreviated model. However, multiple
If there is an intersection, display the intersection closest to the viewpoint
And Step 10 for all pixels on screen
When the process up to 8 is completed, as shown in FIG.
Make sure that all the abbreviated models are projected and drawn on the screen 2.
And Step 109 is the step up to the above.
Detect the abbreviated model drawn on the screen and
This is a step for repeating steps 110 to 113. S
As shown in FIG. 9, clean is a m × n two-dimensional array.
Data is stored, and this sequence data is searched and omitted.
Discover the model. Step 110 is to project on a two-dimensional screen.
Steps to determine the size of the shadow / drawn abbreviated model
It is. For example, as shown in FIG. 9, two omitted models are
It has been projected and drawn. To determine the size
For example, the horizontal (u) direction of the flat screen and the vertical
The size (u) projected in the (v) direction₁, V₁)
You. This u₁And v₁Is entered in step 101.
The minimum size required to display the detailed model
It is determined whether or not it is. Step 111 is the same as step 110.
Detailed model display from the size projected on the screen
For the omitted models that are determined to
Switch to the detailed model and switch for each detailed model.
Steps for repeatedly processing steps 112 and 113
It is Tep. The detailed model is, for example, as shown in
It is usually composed of many graphic elements.
The steps up to step 113 are repeated for the graphic element. Step 112 is a graphic element of the detailed model.
Is a means for determining the intersection of
In the same way as the case, the ray distance that passes through each pixel on the screen
The intersection between the expression and the graphic element is determined. Step 113 is the same as step 112.
Rays that have been determined to have an intersection point across the screen
Position P_SFor the pixels of
And a detailed model is displayed. As described above, in this embodiment, the details entered
The number of parameters or
Generate an abbreviated model with a reduced number of dimensions and first determine intersection points.
Display in an abbreviated model that is easy to
Detailed only for large projections that require detailed information
Displayed as a thin model. Therefore, all details
It is possible to speed up the display process compared to displaying with a model
Since the abbreviated model is automatically generated,
The effect is that there is no need to manually enter. In the above embodiment, the image is projected on the screen.
When displaying a large object with a detailed model
However, when the abbreviated model is displayed, the processing is aborted and details are
You can choose not to display the thin model at all. For this
Is processed when step 108 in FIG. 2 is completed.
You can finish. All objects are displayed in an abbreviated model
By doing so, the display processing time can be speeded up, so
It can be used when checking. Switching from the omitted model to the detailed model
Since the judgment is made by algorithm as described above,
But can also be decided by the judgment of the operator
You. To this end, the means of step 110 in FIG.
Can be realized by replacing the with the dialog processing with the operator
It is. This interactive processing is the plane screen as shown in FIG.
The abbreviated model drawn on the screen
On the display while the operator visually checks the display.
With a pointing device such as a stylus pen.
By designating an abbreviated model to switch to the thin model display
is there. In this way, switching to a detailed model through interactive processing
The operator can choose an abbreviated model
Since it is possible to leave it, the intentional abbreviation is
It is possible. As a method of switching to the detailed model,
Switch based on the distance from the point to the omitted model.
Can also be. The flowchart in this case is shown in FIG.
You. First, in step 101, the detailed model and the view information
In addition, the switch setting value based on the viewpoint-intersection distance is input. Less than
Steps 102 to 107 are the same as above.
Since it exists, the description is omitted. Step 201 Step
Based on the position of the intersection of the abbreviated model and the ray obtained in 107
Then, the distance between the viewpoint and the intersection is calculated. As shown in FIG.
Viewpoint P_VAnd the intersection P on the abbreviated model₀At two points on ray 5
Yes, the distance between these two points can be easily obtained. S
Step 202 is the above-mentioned viewpoint-intersection distance and step 10
The set value input by 1 is compared in magnitude. Set value
If the calculated distance is large, that is, if it is far,
P on the screen by step 203_SPosition (Fig. 8)
The abbreviated model is displayed on the pixel of. On the other hand, than the set value
If small, ie close, step 11 in FIG.
1 to 113 and steps 204 to 206
P_SThe detailed model is displayed at the pixel at the position of. like this
From the abbreviated model to the detailed model depending on the distance from the viewpoint
When switching between all models, omit all models once.
Display as a model and then switch to the detailed model sequentially
Instead of using the
Since Dell is separated, the display man-hours of the abbreviated model are small.
Therefore, the processing speed can be increased. Depending on the size of the model of the object itself
Also, it is possible to switch between the abbreviated model and the detailed model.
FIG. 11 is a flowchart showing this method. First
Step 101 is a step of input,
In addition to the visual field information, the omitted model is generated depending on the size of the model.
Enter the setting value to configure. Step 102 is shown in FIG.
Is the same as Step 301 is detailed as shown in FIG.
It is a means to judge the size of the thin model, and each axis of XYZ.
The size of the model is obtained by projecting in the direction. And
If it is smaller than the setting value input at step 101,
In step 302, an abbreviated model is generated. Sa
In addition, in step 302, as shown in FIG.
Or, if you create an abbreviated model for a part, you can create a detailed model
Replace with. In other words, either the detailed model or the abbreviated model
One of the offsets is assigned to the part or object. Step
The groups 104 and 105 are the same as those in FIG. Step 30
3 corresponds to the object or part in the data structure of FIG.
Model to be detected, and then steps 304 to 308
Repeat. Modes assigned in step 304
Detailed model is determined by determining whether Dell is a detailed model or an abbreviated model.
In the case of, display processing is performed by steps 305 and 306.
However, in the case of the abbreviated model, steps 307 and 308 are performed.
Display processing. In this way, the size of the model of the object
Therefore, if you switch to the omitted model,
The abbreviated model is assigned only by the shape information
Therefore, the omitted display can be performed independently of the viewpoint position.
You. In other words, the size is small regardless of the viewpoint position.
Only the object can be displayed as an abbreviated model. In computer graphics,
Still images created by each frame are continuously displayed at about 30 frames / second.
A moving image is displayed by continuously displaying. This movie table
When showing, only the moving objects on the screen are omitted.
You can switch to Dell and display it. Figure 13
3 and the model information of the graphic element (cylinder) shown in FIG.
It is an example showing the contents. In the figure, 2h is the length of the cylinder
2r is the diameter of the cylinder.
Call it news. The position from the origin O about the center P of the cylinder
Is a_x, A_y, A_zAnd indicates the orientation of the cylinder
The rotation angle is θ_x, Θ_y, Θ_zAnd these are called placement information.
Huh. When an object moves on the display, that is, the screen
First, if the placement information changes between frames
Secondly, there is a case where the visual field information has changed. This
Here, as shown in FIG. 14, when an object is moving on the screen,
A method of displaying the model will be described. Steps
Reference numeral 401 is the details one frame before the frame currently being processed.
This is the step to enter model / field of view information, etc.
Enter detailed model / view information etc.
Power. Step 102 is similar to the example of FIG. Stay
Step 402 is a step of determining the behavior of the model,
Is the information entered in steps 401 and 101?
Changes in the arrangement information and the visual field information are detected. Move here
If it is determined that there is a work, according to step 302
Replace the detailed model with the abbreviated model as shown in Figure 12.
You. The following steps are the same as in the example of FIG.
It is possible to display only objects that are abbreviated models. Movement
In case of the image display, the moving object on the display
Difficult to gaze and recognize detailed model information
I can't. Therefore, the speed of the moving object is an evaluation index
When it is omitted, the image quality is less degraded and
This has the effect of speeding up processing. In the above-described embodiments, detailed models and omissions are made.
The model switching is performed instantaneously with a certain frame as a boundary.
However, the transmittance of the model is defined, and this is
As Dell, change gradually while changing
Can be. For example, in FIG. 1, the display in the first frame
Suppose the image looks like Display 6 by the detailed model. No.
This object starts moving from 2 frames, and is an abbreviated model
The display is switched to, but the switching is complete.
It is the fourth frame. Between this 1st-4th frame
Therefore, the transmittance of the detailed model is 0 as shown in FIG.
%, 33%, 66%, 100%, while omitting model
Changes to 100%, 66%, 33%, 0%. Need
However, the detailed model is displayed in a progressively thinner
The approximate model is displayed as it gradually darkens. In addition, this
Here, the transmittance is a number indicating the rate at which light rays pass through an object,
When the transmittance is 0%, the object is completely visible, and 100% is complete.
It is invisible. Figure 15 (b) shows this method.
It is a flowchart. Steps 401 and 101
Is similar to the case of FIG. Step 501 is already
Enter the transmittance information for the object that is starting to move.
In the current frame of the detailed and abbreviated model
Enter the transmittance. Step 102 to Step 303
Up to this is the same as in the case of FIG. After step 502
Is a means for determining and displaying the intersection of the ray and the model.
You. First, in step 502, the presence or absence of an abbreviated model is detected.
You. For example, one object, such as component 1 in FIG.
Or, for parts, not only detailed models but also omitted models are assigned.
Detects what is being applied. Abbreviated model
For objects that do not have a territory, see step 503 for details.
Display Dell normally. On the other hand, the allocation of the omitted model
In the case of
A transparent display is performed, and then in step 505, the omission mode is set.
Overwrite the transparent display of the file. Overwriting is one pixel
Colors should be mixed and displayed according to the ratio of their transmittance.
And For example, the transmittance of the detailed model is A, and the detailed model is
Display color is C₁And the transmittance of the omitted model is (1-
A), display color is C_TwoThen, the transparent display color C is C = A ・ C₁+ (1-A) C₂ Calculate as follows. In this way a detailed model
Switch to the omitted model while changing the transmittance.
By doing so, they switch while overlapping.
Therefore, it is possible to display a smooth moving image. Stepwise switching from detailed model to abbreviated model
As a replacement method, the detailed model is gradually deformed and omitted
The display can be performed while matching the model. example
For example, as shown in Fig. 16, the detailed model reduces the cylindrical shape.
It is assumed that the model has a rectangular parallelepiped shape. here,
In order to sequentially transform the cylinder into a rectangular parallelepiped,
Define corresponding points on Dell. For example, as shown in the figure,
P for the thin model₁~ P₁₆Is P ′ for the abbreviated model
₁~ P '₁₆Is defined as the corresponding point. 17 is the same as FIG.
It is a top view, in the middle of deformation from the detailed model and the omitted model
6 is a diagram illustrating a method of generating the interpolation model of FIG. I
In addition, the interpolation model to be generated is
If it is intermediate, the corresponding point Q of the interpolation model₁~
Q₈To obtain, the line segment P₁P '₁From line segment P₈P '₈Until
It is sufficient to find the midpoints in sequence. Flow chart of this method
Is shown in FIG. Steps 401 and 101 are shown in FIG.
Is similar to the example. Step 601 inputs corresponding point information
And the detailed model as shown in FIG.
If there is an abbreviated model, define corresponding points for each
You. Steps 102 to 503 are similar to the example of FIG.
It is. Step 602 is between the detailed model and the abbreviated model
Is a step to generate an interpolation model with the shape of
It is generated as shown in 17. And step 603
At, the generated interpolation model is displayed. This
As shown in the figure, the detailed model is deformed in sequence and cut into the omitted model.
To prevent momentary switching by switching
Therefore, it is possible to display a smooth video.
is there. Since the abbreviated model is generated from the detailed model,
Instead, a three-dimensional abbreviated model is first defined as shape data.
In other words, the transmittance data that describes the transparency of an object to light rays.
Data is described as mapping data in a two-dimensional table format.
Memorize and paste the mapping data to the shape model
It is also possible to define a detailed model and display it.
is there. As shown in FIG. 19, the three-dimensional shape data is saved as
Define a rough model. For example, in the example in the figure, the abbreviated model
4 vertices P₁~ P_FourCoordinate value (x₁, Y₁, Z₁) ~ (X_Four,
y_Four, Z_Four) Is defined. In addition, the transmittance data
Two-dimensional data with such a distribution, for example the shaded area
The transmittance is 100%, and the transmittance is 0% except the shaded area. This
Here, with the mapping means, the transmittance data can be displayed in the omitted model.
In order to paste the
It is necessary to establish the correspondence. For example, in this embodiment,
Point M at 4 corners of transmittance data₁~ M_FourIs the abbreviated model 4 peak
Point P₁~ P_FourRespectively correspond to. Other than the apex
The correspondence between the points is interpolated at the position from the vertex. Figure
20 is a flowchart for explaining the present embodiment.
You. In step 101, input detailed model and view information
I do. Detailed model information is omitted in this step.
This is the correspondence between Dell and the transmittance data and both.
Enter all the information. In this embodiment, detailed model and omission
Models are switched based on the distance from the viewpoint.
You. However, as described above, switching between the detailed model and the omitted model
There are several methods to change the
Can also be combined in this embodiment. Step 104
The subsequent steps are almost the same as those in FIG.
The iterative process for the detailed model after 4 is shown in FIG.
As shown in, the omitted model and the transmittance data
It is processed against. Intersection of step 205
When the intersection is in the part where the transmittance is 100%,
Has no intersections, as the rays pass through the model.
And then processed. On the other hand, the intersection is in the area where the transmittance is 0%.
If it does, it is treated as if there was an intersection. these
As a result of the processing, details are displayed on the display as shown in FIG.
Obtaining a thin model representation and an abbreviated model representation
Can be. In this way, the transmittance data is mapped to the omitted model.
Transparency by defining detailed models
The light is transmitted through the part where the ratio is 100%, so it looks like an object.
Since the body is not displayed, the outline of a complicated object is
Can be expressed only with cloth, and it is complicated with a small amount of shape data.
It is possible to describe various objects. Also, use of transmittance data
/ By not using it, you can switch between the detailed model and the omitted model.
Possible and less important objects are omitted
By doing so, the processing speed can be increased. The transmittance data and the color data are mapped to the omitted model.
The detailed model is also displayed by performing the wrapping process.
be able to. The omitted model and transmittance data shown in FIG.
22 to the color data shown in FIG. This color day
The data is a two-dimensional table format like the transmittance data.
Similarly, the corresponding point M ′ with the abbreviated model₁~ M '_FourDetermined
You. Then, the same processing as that shown in FIG.
There is a detailed model display on the display 8.
Or you can get the display by the abbreviated model. This
By adding more color data like
Patterns can be registered as two-dimensional data, so more precise
A detailed model display can be obtained. The transmittance data, color data, and
You can also add normal data to to get a detailed model display.
Wear. FIG. 24 is a diagram showing the concept of additional normal line data.
The distribution of normal vectors on the object is in a two-dimensional table format
It is stored in. Transmittance data and color data
And the corresponding point M ′₁~ M '_FourThe abbreviated model
Establish a correspondence with. Between the light source vector and the normal vector
When performing the inner product calculation and determining the display color, the normal of the object is
Instead of calculating the normal data on the table,
I will use it. Then, as shown in Fig. 24, it is actually stored.
The normal data is as shown in (b), and the shape of the abbreviated model is
Although the shape is a plane, it is calculated by the inner product calculation with the light source vector.
When the display is decided, it will be displayed as having a surface like (a).
It is. FIG. 25 shows an abbreviated model with transmittance data and color data.
And normal data were added and displayed as a detailed model.
It is an example. In addition, the display example by the abbreviated model is the case of FIG.
Normal data that is similar to
Since it is possible to define various normal distributions, complex surface irregularities
An object with can be displayed as a detailed model. The omission model has transmittance data, color data, and modulus.
A detailed model table is created by giving line data and vertex normal data.
You can also get an indication. FIG. 26 shows the vertex normal vector N₁
~ N_FourTo the four vertices P₁~ P_FourThe example given to
Specify the direction to spread to
This is an example of attaching and displaying. Figure 27 shows a table like a curved surface
It is a figure which shows the reason shown. Now as shown in (a)
N₁And N_FourFrom the vector interpolation of N_FourTo calculate N_Two
And N_ThreeTo N_A′ Is calculated. And N_AAnd N_AFrom ’
Vector interpolation to the normal vector in the abbreviated model
Ask for le. As a result (b),
All normals of are obtained by interpolation. Within the light source vector
If you use this normal vector for product calculation,
The display brightness changes smoothly on the top and it looks like a curved surface.
You. In addition, the normal line obtained by this interpolation is shown in FIG.
Vector addition and display of radiation data on a two-dimensional table
Then, the shape data is a plane as shown in (c).
However, the detailed model is an object with more unevenness on the curved surface.
Can be displayed. The value stored as mapping data
In addition to the above, input optical characteristics such as reflection coefficient
It is possible to This allows optical features on the surface.
Objects with changing sex can also be displayed. A single abbreviated model is used for transmission data and color data.
Rather than assigning data and normal data,
These data can be added to the abbreviated model that has elements. Figure
In the example shown in 28, the abbreviated model is a set of 6 plane elements.
It is a body and the vertex is P₁~ P₁₂Has 12 of. like this
In case of abbreviated model, it corresponds to each vertex
Define corresponding points in the data in 2D table format.
In the case of the figure, M₁~ M₁₂, M '₁~ M '₁₂, M ″₁
~ M "₁₂Is to specify. In this way,
As long as correspondence is specified, the abbreviated model and detailed model
The display can be realized by the flowchart shown in FIG.
You. In this way, as shown in FIG.
Display by detailed model and table by abbreviated model on a.
You can get an indication. Generate and display an abbreviated model from the detailed model
When you do, assign one omitted model to the same object
Instead of assigning multiple omitted models with different levels of detail.
It can also be displayed. In the example shown in FIG. 30, parts
Allocate n omitted models and detailed models for 1
I have. Where the number of parameters or dimensions from the detailed model
Reduce the number to generate an abbreviated model, but
Or the one with the smallest number of dimensions is called the first omitted model,
Hereinafter, the second, ..., Nth omitted model will be referred to. FIG.
1 assigns and displays abbreviated models with different levels of detail
6 is a flowchart showing a method. First, step 701
Then, in addition to the detailed model and field of view information, enter the switching setting value.
You. This is a value to specify the abbreviated model to be displayed
Then, switching is performed according to the distance from the viewpoint as in this embodiment.
When performing, specify n distance values from the set values 1 to n.
Show. These switching set values are set in the order of increasing distance from the viewpoint 1,
Set value 2, ... Set value n. Steps 104 and 1
05 is similar to the example of FIG. Step 702 is the most
For the first abbreviated model with few parameters or dimensions
Means to repeat the following steps. S
Step 702 and step 107 are the same as in the example of FIG.
It is. Step 703 is calculated in Step 201.
The viewpoint-intersection distance that has been set and the input in step 701.
This is a step of making a comparison with the changed switching set value. Perspective
Objects farther away than the farthest setting value 1 from
In step 704, the first omitted model is displayed. Setting
If the object is at a distance between the constant value 1 and the set value 2, then step 7
Check the intersection of the second abbreviated model and the ray with 05.
Display this, if any. Objects closer to the set value n are
Check the intersection with the ray using 705
Display a thin model. Now, assuming that n = 2,
2 The omission model is generated as shown in FIGS. 5 and 6.
It is a circumscribed rectangular parallelepiped of the detailed model. Then, this second omission
A first omitted model can be generated from the model. That is, in FIG.
As shown, generate a circumscribing sphere with radius r around point C.
The first omitted model. At this time, point C is the circumscribed rectangular parallelepiped
It is the center of gravity, and the radius r is 1/2 the length of the diagonal of the circumscribed rectangular parallelepiped.
That's it. The circumscribed sphere is described by one quadratic equation
Therefore, it is better than the circumscribed rectangular parallelepiped described by the six plane equations.
The number of meters is decreasing. In this way, some omissions
An abbreviated model with fewer parameters or dimensions than the model
Less important by assigning and displaying Dell
Faster display time as objects can be displayed in a more simplified manner
Is effective in Generate the first to n-th omitted models from the detailed model.
As a method to achieve this, change the number of divisions of the figure.
But it is possible. In the example shown in FIG. 33, the detailed model is
It has a cylindrical shape, and it is divided into 16
The second omitted model is a prism. And the second ministry
The first model is an octagonal prism with a reduced number of models.
Use as a model. The first omitted model is better than the second omitted model
The number of planes is small and it is made to describe with few parameters.
So, if you assign this to a less important object, the display time
It is possible to speed up. Evaluation of the number of divisions such as distance and size
Value function can be set automatically,
It is not necessary to save the abbreviated model as data.
The data can be made compact. By reducing the number of dimensions, it is possible to save more detail.
As a method of calculating and assigning a rough model, complete quadratic
The original figure can also be used. For example, as shown in Figure 34
The three-dimensional second abbreviation model projected on the screen
Circumscribing figure is obtained in the state and divided as the first omitted model.
Dedicate If the two-dimensional figure is assigned in this way, the display process
Since the processing becomes extremely simple, it is possible to speed up the display time.
is there. In the above example, is the omitted model a detailed model?
, It was automatically generated by an algorithm.
But the abbreviated model is defined across the parts
In some cases, the operator will give instructions and display it in advance.
You can do it. FIG. 35 is based on operator instruction
It is a figure which shows the definition method of an omission model. For example, in FIG.
As shown in (a), the object 1, the part 1, the part 2, and the part 3 are ORed.
It is assumed that it is defined by a bond (denoted as U), and details
As a model, it has a shape in which three cylinders are stacked as shown in the figure.
Let's do it. This is all represented by a detailed model
State Object 1 = Part 1U Part 2U Part 3 Write as. Next, as shown in FIG. 5B, only the component 1
When switching to the omitted model, Object 1 = (Part 1) U Part 2 U Part 3 Enclose parts to be switched to the omitted model in parentheses, such as
Instruct. Similarly, as shown in FIG.
When making the part 2 and the omitted model, Object 1 = (Part 1U Part 2) U Part 3 And, as shown in FIG. 35 (d), all the models are omitted.
In case of Object 1 = (part 1U part 2U part 3) Define as follows and assign the abbreviated model. Real truth
In the example, the operator can instruct the operator to assign the omitted model.
It is possible to apply, and the texture is finer than when automatically generated
In addition, it is possible to control the omitted model. According to the embodiment of the present invention, it is important in the screen.
Automatically identify inferior objects and adjust parameters from detailed models.
Automatically generate an abbreviated model with the number of data or dimensions reduced.
Since it can be displayed, it is effective for speeding up the display.
There is. For example, find the intersection of the 3D model and the line of sight
In this case, the function that describes the model and the viewpoint that is a straight line
Treated as a point finding problem, but with higher-order functions and straight lines
The intersection is not easily found and requires a great deal of processing time.
However, if the number of dimensions is reduced to the first or second dimension,
If it is an abbreviated model, the intersection of this model and the line of sight is extremely
Can be easily requested. Also, the determination of switching to the omitted model and
All model generation is automatic and
There is no need for a pelator to intervene. For example, all objects
If you define one detailed model and one omitted model in,
If there is no automatic generation function of the abbreviated model, double the size of the object
Number of models must be entered by the operator, but the book
In the embodiment of the invention, only the detailed model needs to be input.
It is also effective in reducing man-hours. [0051] According to the present invention, a natural image can be recorded at high speed.
Computer graphics can be displayed.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram and a hardware configuration diagram of an embodiment of the present invention. FIG. 2 is a flowchart for realizing by a computer algorithm. FIG. 3 is an explanatory diagram of graphic elements forming a detailed model. FIG. 4 is a tree structure diagram showing the configuration of graphic elements. FIG. 5 is an explanatory diagram of a method of obtaining an abbreviated model from a detailed model. FIG. 6 is an explanatory diagram of a plane forming an abbreviated model. FIG. 7 is a tree structure diagram showing a configuration of an omitted model after allocation. FIG. 8 is an explanatory diagram of a method of projecting an abbreviated model on a screen. FIG. 9 is an explanatory diagram of an abbreviated model projected on a screen. FIG. 10 is a flowchart when models are switched according to the viewpoint-intersection distance. FIG. 11 is a flowchart in the case of performing model switching according to the size of the omitted model. FIG. 12 is a tree structure diagram showing allocation of models in the case of FIG. FIG. 13 is an explanatory diagram of model information of graphic elements. FIG. 14 is a flowchart in the case of performing model switching for a moving object. 15A and 15B are an explanatory diagram and a flow chart when a model is switched while changing the transmittance. FIG. 16 is an explanatory diagram of corresponding points between the detailed model and the omitted model. 17 is an explanatory diagram of a method of generating an interpolation model in the top view of FIG. FIG. 18 is a flowchart of a case where a detailed model is deformed and an abbreviated model is switched. FIG. 19 is an explanatory diagram of an abbreviated model and transmittance data. FIG. 20 is a flow chart of a method for providing detailed model display by adding transmittance data to an omitted model by mapping. FIG. 21 is an explanatory diagram of the display of a detailed model and an abbreviated model obtained from the display by the method of FIG. 20. FIG. 22 is an explanatory diagram of color data added by mapping of an abbreviated model. FIG. 23 is an explanatory diagram of a display by a detailed model and an abbreviated model on the display when the color data of FIG. 22 is added to the data of FIG. FIG. 24 is an explanatory diagram of normal line data added to the omitted model. FIG. 25 is an explanatory diagram of a display by a detailed model on the display when the normal line data of FIG. 24 is added to the data of FIGS. 19 and 22. FIG. 26 is an explanatory diagram of vertex normals given to the omitted model. FIG. 27 is an explanatory diagram of an interpolation method of vertex normals. FIG. 28 is an explanatory diagram of a case where the omitted model is composed of a plurality of graphic elements. FIG. 29 is an explanatory diagram of a detailed model and an abbreviated model when the data of FIG. 28 is displayed on the display. FIG. 30 is a tree structure diagram showing a data structure when a plurality of omitted models with different degrees of detail are assigned to a single part. 31 is a flow chart of a method of displaying the data of FIG. FIG. 32 is an explanatory diagram showing a method of generating a first omission model based on a circumscribing sphere from a second omission model based on a circumscribing cuboid. FIG. 33 is a diagram illustrating the second method by controlling the number of divisions of the figure from the detailed model.
It is explanatory drawing which shows the method of generating an abbreviated model and a 1st abbreviated model. FIG. 34 is an explanatory diagram of a method of generating a first omitted model by subtracting the number of dimensions from the second omitted model. FIG. 35 is an explanatory diagram showing a description method when assigning models with different degrees of detail according to operator instructions. [Explanation of Codes] 1 ... Viewpoint, 2 ... Screen, 3 ... Detailed model, 4 ... Abbreviated model, 5 ... Rays, 6 ... Detailed model display, 7 ... Abbreviated model display, 8 ... Display screen.

   ────────────────────────────────────────────────── ─── Continuation of front page    (56) References Computer Graphic               s, vol. 16, no. 3, p9-18,               F. C. Crow, "A More F               flexible Timage Gene               relation Environmen               t "

Claims (1)

(57) [Claims] In a computer graphics display method for storing a three-dimensional detailed model of an object and its three-dimensional omitted model, and switching between the detailed model and the omitted model for display on a display device , depending on the moving speed of the model to be displayed. With the detailed model
Switch between the abbreviated model and display on the display device.
Computer graphics display wherein the cormorant. 2. A computer graphics display method for storing a three-dimensional detailed model of an object and its three-dimensional omitted model and switching between the detailed model and the omitted model for display on a display device, according to the moving speed of the model to be displayed. is displayed on the display device by switching the abbreviated model and the detailed model, display switching between abbreviated model and the detailed model
When displaying on the device, the detailed model and abbreviated model
Switching while changing the transmittance, which is the shade of each display
A computer graphics display method characterized by performing replacement . 3. In a computer graphics display method for storing a three-dimensional detailed model of an object and its three-dimensional omitted model, and switching between the detailed model and the omitted model for display on a display device , the size of the model to be displayed on the screen Is judged,
If the size is larger than the preset value,
Displays a thin model and the size is smaller than the preset value.
If not, switch to display the detailed model
When the detailed model and the abbreviated model are switched and displayed on the display device, the detailed model and the abbreviated model are displayed.
A computer graphics display method characterized in that switching is performed while changing the transmittance, which is the shade of each display .