JP6444826B2 - 3D line graph viewpoint control device and 3D line graph viewpoint control program - Google Patents

Description

  Embodiments described herein relate generally to a three-dimensional line graph viewpoint control device and a three-dimensional line graph viewpoint control program.

  For the modeled three-dimensional shape, for example, rendering processing for rendering on a two-dimensional screen is performed in consideration of the position and orientation of the viewpoint and the light source from the viewpoint of enhancing the realism.

  Among the three-dimensional models, an algorithm has been proposed that calculates an optimal viewpoint that maximizes the amount of information representing the visible area when rendering an object.

  However, with regard to the three-dimensional line graph, the state in which the data of the three-dimensional graph is plotted may overlap with the previous series, and the algorithm cannot be applied as it is.

  Unlike an object, a three-dimensional line graph does not need to rotate the viewpoint in all directions to obtain an optimal viewpoint so that it makes little sense when viewed from directly above. This means that in order to draw a three-dimensional line graph in an easy-to-view manner, a mechanism for managing the viewpoint and limiting the rotation range by the user operation is necessary.

`` Automatic View Selection Using Viewpoint Entropy and its Application to Image-Based Modeling '' Pere-Pau Vazquez, Miquel Feixas, Mateu Sbert and Wolfgang Heidrich COMPUTER GRAPHICS Forum Volume 22, Issue 4, pages 689-700, December 2003 "Previewing Volume Decomposition Through Optimal Viewpoints" S. Takahashi, I. Fujishiro, Y. Takeshima, and C. Bi, Dagstuhl Follow-Up Seminar Book "Scientific Visualization: Interactions, Features, Metaphors", in Scientific Visualization: Interactions, Features, Metaphors 2011, (H. Hagen ed.) Dagstuhl Follow-Ups Series, Vol. 2, Schloss Dagstuhl--Leibniz-Zentrum fuer Informatik, pp. 346-359, November, 2011.

JP-A-9-81774 JP 2004-361112 A

  The problem to be solved by the present invention is a three-dimensional line graph viewpoint capable of calculating an optimum viewpoint and viewing angle for drawing a line graph having information plotted in a three-dimensional space on a display area of a two-dimensional screen. It is to provide a control device and a three-dimensional line graph viewpoint control program.

The 3D line graph viewpoint control device of the embodiment is a 3D line graph viewpoint control device that sets a 3D space on a display area of a 2D screen and displays a 3D line graph on the display area. An input unit that accepts input of initial values of viewpoints and viewpoint distances, a data storage unit that stores data for drawing the three-dimensional line graph, and data of initial values of viewpoints and viewpoint distances from the input units, Each of the three-dimensional line graph data is fetched from the data storage unit, and the information amount representing the amount that the three-dimensional line graph can be visually recognized using the coordinates and the viewing angle of an arbitrary viewpoint given as an initial value is quantified. a calculation unit in which the information amount using the entropy equation of one viewpoint to calculate the coordinates and viewing angles of the viewpoint becomes maximum, the coordinate of the viewpoint calculated by the arithmetic unit And a display unit for displaying the 3-dimensional line graph based on the corner.

The three-dimensional line graph viewpoint control program of the embodiment sets a three-dimensional space on a display area of a two-dimensional screen and displays a three-dimensional line graph on the display area. Based on the function of accepting the input of the initial value of the viewpoint distance, the function of capturing the data for drawing the three-dimensional line graph, the data of the initial value of the viewpoint and the viewpoint distance, the data of the three-dimensional line graph, The amount of information is maximized by using an entropy formula for the viewpoint, which is a numerical value of the amount of information representing the amount that the three-dimensional line graph can be viewed using the coordinates and viewing angle of an arbitrary viewpoint given as an initial value. A function for calculating the coordinates and viewing angle of the viewpoint, and a function for displaying the three-dimensional line graph on the display area based on the calculated coordinates and viewing angle of the viewpoint To realize the door.

It is a block diagram which shows schematic structure of the three-dimensional line graph viewpoint control apparatus which concerns on embodiment of this invention. It is a figure explaining the relationship between a three-dimensional line graph and a viewpoint. It is a flowchart which shows the flow of the process which selects a single viewpoint. It is a flowchart which shows the flow of the process which selects a some viewpoint. It is a figure explaining the relationship between a viewpoint and the center point of graph area space. It is a figure explaining adjustment of the distance between a viewpoint and a graph center point. It is a figure explaining the movement of a viewpoint. It is a figure explaining the viewpoint to rotate.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the drawings, the same portions are denoted by the same reference numerals, and redundant description is omitted.

  First, main terms used in the present embodiment will be described.

  “Display area” refers to a two-dimensional area displaying a three-dimensional space on the screen. In the display area, the content of a three-dimensional space projected from a certain viewpoint in the space onto a two-dimensional plane is drawn. Which projection method is used to project onto a two-dimensional plane differs depending on the application.

  “Projection plane” refers to a two-dimensional plane on which a three-dimensional model (graph) is projected onto a screen.

  “Viewpoint” means what determines where and in what direction the space is viewed. By changing the position of the viewpoint and the direction of the viewpoint (gaze direction), an object in the three-dimensional space can be viewed from different angles. The viewpoint is defined by the coordinates (x, y, z) of the viewpoint and the line-of-sight direction (vx, vy, vz, θ). The line-of-sight direction (line-of-sight axis) is obtained by rotating the reference line-of-sight (0, 0, −1) by θ radians around arbitrary rotation axes (vx, vy, vz). (1, 0, 0, θ) represents vertical line-of-sight movement, (0, 1, 0, θ) represents horizontal line-of-sight movement, and (0, 0, 1, θ) represents rotation of the visual axis. . A plurality of viewpoints can be set in the three-dimensional space.

  “Field of view (FOV)” refers to an angle formed by two straight lines connecting the viewpoint and the end of the projection plane. There are horizontal viewing angles and vertical viewing angles. In this embodiment, a vertical viewing angle is used.

  A “three-dimensional line graph” refers to a result of plotting a series of data having three types of information in a three-dimensional space displayed on the X, Y, and Z axes and connecting them with lines.

  “Series” refers to a series of data having two or three types of information connected in one axial direction.

  The “graph center point” refers to a coordinate value corresponding to the center of the graph area space.

  In the present embodiment, an optimal viewpoint and viewing angle (or a distance between the line of sight and the graph center point) for drawing a three-dimensional line graph on the display area (projection plane) of the two-dimensional screen are obtained. Here, the viewpoint indicates the line-of-sight direction of the Z-axis of the three-dimensional line graph display, and coordinates and line-of-sight directions that maximize the amount of information representing the amount that the three-dimensional line graph can be seen (viewed). Specified by Further, the viewing angle (or the distance between the line of sight and the graph center point) is a viewing angle within a range in which the three-dimensional line graph is within the projection plane. In the present embodiment, a viewpoint with a large amount of information is calculated in consideration of the shape of a three-dimensional line graph, for example, the degree of alignment (intervals) between the graphs.

  FIG. 1 is a block diagram showing a schematic configuration of a three-dimensional line graph viewpoint control apparatus according to an embodiment of the present invention. This apparatus is realized using a general-purpose computer (for example, a personal computer (PC) or the like), software that operates on the computer, and software that operates on the cloud or the Web. The computer includes an engineering workstation (EWS) suitable for CAD (Computer Aided Design) and CAE (Computer Aided Engineering). In the computer according to this embodiment, a viewpoint and a viewpoint distance are set in a three-dimensional line graph viewpoint control device that sets a three-dimensional space on a display area of a two-dimensional screen and displays a three-dimensional line graph on the display area. 3D line graph based on the function of accepting the initial value input, the function of fetching data for drawing the 3D line graph, the initial value data of the viewpoint and viewpoint distance, and the data of the 3D line graph A function that calculates the coordinates and viewing angle of the viewpoint using the entropy formula of the viewpoint, which is a numerical value of the amount of information that represents the amount that can be viewed, and a display area that displays a three-dimensional line graph based on the calculated coordinates and viewing angle of the viewpoint It can also be implemented as a program that realizes the function displayed above.

  As shown in FIG. 1, the three-dimensional line graph viewpoint control device 1 according to the present embodiment mainly includes an input unit 10, an arithmetic processing unit 20, a display unit 30, and a data storage unit 40.

  The input unit 10 receives an initial value of a viewpoint or a viewpoint distance. The initial values of the input viewpoint and viewpoint distance are sent to the arithmetic processing unit 20.

  The data storage unit 40 stores data for drawing a three-dimensional line graph. A three-dimensional line graph is a result of plotting a series of data having three types of information on the X, Y, and Z axes and connecting them with lines. The three-dimensional line graph is composed of a plurality of series, for example, m series. The series is a series of data having two or three types of information connected in any one of the X, Y, and Z axes.

  The arithmetic processing unit 20 takes in the data of the initial values of the viewpoint and the viewpoint distance from the input unit 10 and the data of the three-dimensional line graph from the data storage unit 40, respectively, and represents the amount by which the three-dimensional line graph can be seen (viewed). The optimal viewpoint and viewing angle that maximize the amount of information are calculated. Details of the calculation method will be described later.

  The display unit 30 sets a three-dimensional space displayed on the X, Y, and Z axes, for example, on a display area of a two-dimensional screen displayed on the X, Y axes, and displays a three-dimensional line graph on the area. To do. In the present embodiment, a three-dimensional line graph in which data is stored in the data storage unit 40 is displayed on the display unit 30 in advance. The display unit 30 displays a three-dimensional line graph based on the optimal viewpoint and viewing angle calculated by the arithmetic processing unit 20.

  The optimal viewpoint and viewing angle calculated by the arithmetic processing unit 20 are displayed to the user.

  Next, the optimal viewpoint calculation processing in the three-dimensional line graph viewpoint control apparatus 1 configured as described above will be described in detail.

<Optimal viewpoint>
FIG. 2 is a diagram illustrating the relationship between the three-dimensional line graph and the viewpoint. As shown in FIG. 2, a plurality of series are displayed in an XY parallel plane frame representing a two-dimensional display area.

  In the example shown in FIG. 2, m series are drawn. From the viewpoint located in the Z-axis direction, since a plurality of series having respective shapes are drawn at equal intervals or different intervals, it is not possible to see all the series. That is, a certain series is visible and hidden by the shape of a series (referred to as a forward series) that is positioned forward from the viewpoint.

In the present embodiment, when calculating the optimum viewpoint, the viewpoint is entropy calculated by quantifying the amount of information in which the three-dimensional line graph can be seen. In the example shown in FIG. 2, the sequence i is visible and hidden by the forward sequence. When both are overlapped, the area that is visible from the viewpoint is positive (+), and the area that is not visible from the viewpoint is negative (−). In other words, the amount of information in which the series i can be seen is the sum of the area of the front series and the XY parallel plane frame.

here,
E: Amount of information
V: Given perspective
Ai: Amount of visible series i
S: Sum of integrals of each series
m: Number of series. The above Ai is preferably the sum of the areas of the front series and the XY parallel plane frame, for example.

<Single viewpoint selection>
FIG. 3 is a flowchart showing a flow of processing for selecting a single viewpoint.

  First, an initial viewpoint and an initial viewpoint distance are set (step S31).

  Next, the maximum value of the information amount that can be seen in the three-dimensional line graph is set to zero (step S32).

  Next, the viewpoint is moved by the viewpoint movement unit in the XZ parallel circle (step S33). Here, even if the viewpoint is moved in units of, for example, 1 degree or 5 degrees, the increase or decrease in the information amount is slight. Therefore, it is preferable to set π / 12 = 15 degrees, for example, in an arc degree unit where 180 degrees = π radians. Further, as the viewpoint movement direction (direction), the movement in the −Y direction is, for example, movement within the range of the height of the graph area.

  Subsequently, it is determined whether or not the entire three-dimensional line graph is displayed (step S34).

  If the entire three-dimensional line graph is not displayed (No in step S34), the distance between the viewpoint and the graph center point is extended (step S35), and the process returns to step S34.

  On the other hand, if the entire three-dimensional line graph is displayed (Yes in step S34), the graph information amount is calculated by the above-described entropy equation and set as E (step S36).

  Next, it is determined whether or not the graph information amount E is larger than the maximum value (step S37).

  If the graph information amount E is larger than the maximum value (Yes in step S37), the maximum value = E is set (step S38), and it is determined whether or not the moving distance is larger than 2π radians (step S39).

  On the other hand, if the graph information amount E is not larger than the maximum value (No in step S37), the process proceeds to step S39.

  Next, if the moving distance is not greater than 2π radians (No in step S39), the process returns to step S33.

  On the other hand, if the movement distance is greater than 2π radians (Yes in step S39), the movement is completed, and the process of selecting a single viewpoint is terminated.

<Multiple viewpoint selection>
Next, processing for selecting a plurality of viewpoints will be described. FIG. 4 is a flowchart showing a flow of processing for selecting a plurality of viewpoints.

  First, an initial viewpoint and an initial viewpoint distance are set (step S401).

  Next, the maximum value of the amount of information that can be seen in the three-dimensional line graph is set to zero (step S402). Here, as an example of selecting two viewpoints, the maximum value Max1 of the information amount of one viewpoint and the maximum value Max2 of the information amount of the other viewpoint are each set to zero.

  Next, the viewpoint is moved by the viewpoint movement unit in the XZ parallel circle (step S403). Here, the viewpoint movement unit is preferably π / 12 = 15 degrees, for example. Further, as the viewpoint movement direction (direction), the movement in the −Y direction is, for example, movement within the range of the height of the graph area.

  Subsequently, it is determined whether or not the entire three-dimensional line graph is displayed (step S404).

  If the entire three-dimensional line graph is not displayed (No in step S404), the distance between the viewpoint and the graph center point is extended (step S405), and the process returns to step S404.

  On the other hand, if the entire three-dimensional line graph is displayed (Yes in step S404), the graph information amount is calculated by the above-described entropy formula and set as E (step S406).

  Next, it is determined whether or not the graph information amount E is larger than the maximum value Max1 (step S407).

  If the graph information amount E is larger than the maximum value Max1 (Yes in step S407), the maximum value Max1 = E is set (step S408), and the process proceeds to step S411.

  If the graph information amount E is not larger than the maximum value Max1 (No in step S407), it is determined whether or not the graph information amount E is larger than the maximum value Max2 (step S409).

  If the graph information amount E is larger than the maximum value Max2 (Yes in step S409), the maximum value Max2 = E is set (step S410). On the other hand, if the graph information amount E is not larger than the maximum value Max2 (No in step S409), the process proceeds to step S411.

  Subsequently, it is determined whether or not the moving distance is greater than 2π radians (step S411).

  Next, if the moving distance is not greater than 2π radians (No in step S411), the process returns to step S403.

  On the other hand, if the movement distance is larger than 2π radians (Yes in step S411), the movement is completed, and the process of selecting a plurality of viewpoints is terminated.

<Setting the initial values for the viewpoint and line-of-sight direction>
The initial values of the viewpoint and the line-of-sight direction can be arbitrarily set by the user. For example, according to X3D application software which is a file format for expressing three-dimensional computer graphics, initial values can be described as follows.

<Viewpoint position = “0 0 10” orientation = “0 0 0 1” field Of View = “π / 4”>
<Transform translation = “…”>
Further, the center point of the graph area space (graph center point) can be set as shown in FIG.

X: n of X / 2
Y: Max (y (x, z)) / 2
Z: n of Z / 2
n: Total number of data, y (x, z)> 0. Here, the data indicates the increments of the X axis and the Z axis. For example, if the increment of the X axis is 24, n = 24 of the X axis, and if the increment of the Z axis is 12, the n axis of the Z axis is equal to n = 24. 12.

<Distance between viewpoint and graph center point>
FIG. 6 is a diagram for explaining adjustment of the distance between the viewpoint and the graph center point. As shown in FIG. 6, in order to extend the distance between the viewpoint and the graph center point, an equivalent processing result can be obtained by increasing the viewing angle.

<Moving the viewpoint>
FIG. 7 is a diagram for explaining the movement of the viewpoint. In the example shown in FIG. 7, the viewpoint moves on the XZ parallel circle by a unit. The Y of the parallel circle is the Y of the graph center point. The maximum movement distance of the viewpoint is 2π radians, and when the 2π radians are moved, the viewpoint returns to the initial point.

  It is also possible to provide a plurality of XZ parallel circles by shifting along the Y axis.

<Rotating viewpoint>
FIG. 8 is a diagram for explaining a rotating viewpoint. For example, it is possible to accept key operations by a user (a well-known technique can be applied and will not be described in detail here), and as shown in FIG. 8, the line-of-sight direction (line-of-sight axis) is aligned with the graph center point on the XZ parallel circle The viewpoint selected by key operation can be changed.

[Example]
Next, a calculation example of the information amount E described above will be described as an example of the present embodiment. Here, in order to facilitate the calculation, the number of series m is 12, the amount Ai that the series i is visible is uniformly 30, and the sum S of integrals of each series is 50. If these are applied to the above equation,

E is about 1.597.

(Modification 1 of this embodiment)
Next, Modification 1 of the present embodiment will be described. A plurality of the above viewpoints are obtained, and the plurality of viewpoints are selected by a user operation. It is preferable to change the layout from the selected viewpoint to a layout that maximizes the amount of information, and to set the grid interval of each axis that maximizes the amount of information in the three-dimensional graph.

(Modification 2 of this embodiment)
Next, a second modification of the present embodiment will be described. In the example illustrated in FIG. 8, for each viewpoint from (1) to (5), an animation that alternately displays a difference viewpoint between the left eye and the right eye parallax can be provided. In this way, parallax for the user to recognize as a three-dimensional line graph can be displayed.

  As described above, according to this embodiment, when drawing a three-dimensional line graph, it is possible to obtain an optimal viewpoint that maximizes the amount of information that can be visually recognized. In addition, a plurality of viewpoints with a large amount of information can be used as a user's viewpoint changing operation.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 1 ... 3D line graph viewpoint control apparatus 10 ... Input part 20 ... Arithmetic processing part 30 ... Display part 40 ... Data storage part

Claims (9)

A 3D line graph viewpoint control device that sets a 3D space on a display area of a 2D screen and displays a 3D line graph on the display area,
An input unit for receiving input of initial values of a viewpoint and a viewpoint distance;
A data storage unit for storing data for drawing the three-dimensional line graph;
Data of initial values of viewpoints and viewpoint distances from the input unit, and data of the three-dimensional line graph from the data storage unit, respectively, and the three-dimensional using the coordinates and viewing angles of arbitrary viewpoints given as initial values A calculation unit that calculates the coordinates and viewing angle of the viewpoint at which the information amount is maximized using an entropy formula of the viewpoint, which is a numerical value of the amount of information that represents the amount that the line graph can be visually recognized;
A three-dimensional line graph viewpoint control device comprising: a display unit configured to display the three-dimensional line graph based on viewpoint coordinates and a viewing angle calculated by the arithmetic unit. The three-dimensional line graph is composed of a plurality of series, and the series is composed of a series of data connected in one axial direction,
E: Amount of information
V: Given perspective
Ai: Amount by which the sequence i is visible by the forward sequence when the plurality of sequences are drawn on the display area of the two-dimensional screen
S: Sum of integrals of each series
m is the number of series
The entropy formula is

The three-dimensional line graph viewpoint control device according to claim 1.   When the series displayed on the XY parallel plane frame representing the display area of the two-dimensional area is obscured by a forward series positioned forward when viewed from a certain viewpoint located in the Z-axis direction, from a certain viewpoint 3. The three-dimensional line graph viewpoint according to claim 2, wherein an amount of the series that is visible based on an area that is visible and an area that is not visible from a certain viewpoint is a sum of an area that forms a front series and an XY parallel plane frame. Control device.   The three-dimensional line graph viewpoint control apparatus according to claim 3, wherein the viewpoint movement unit is π radians / 12.   The three-dimensional line graph viewpoint control device according to claim 4, wherein, when selecting a viewpoint, the distance between the viewpoint and the graph center point is increased and adjusted.   The three-dimensional line graph viewpoint control device according to claim 5, wherein the viewpoint is rotated on a parallel circle with a line-of-sight direction aligned with the graph center point.   The three-dimensional line graph viewpoint control apparatus according to claim 6, wherein when a plurality of viewpoints are selected, selection by a user can be accepted. In a 3D line graph viewpoint control device that sets a 3D space on a display area of a 2D screen and displays a 3D line graph on the display area,
A function that accepts input of initial values of viewpoint and viewpoint distance;
A function of capturing data for drawing the three-dimensional line graph;
Information representing the amount that the three-dimensional line graph can be visually recognized using the coordinates and the viewing angle of an arbitrary viewpoint given as an initial value based on the data of the initial values of the viewpoint and the viewpoint distance and the data of the three-dimensional line graph A function for calculating the coordinates and viewing angle of the viewpoint that maximizes the information amount using an entropy formula of the viewpoint that is a numerical value of the amount;
A three-dimensional line graph viewpoint control program for realizing the function of displaying the three-dimensional line graph on the display area based on the calculated viewpoint coordinates and viewing angle. The three-dimensional line graph is composed of a plurality of series, and the series is composed of a series of data connected in one axial direction,
E: Amount of information
V: Given perspective
Ai: Amount by which the sequence i is visible by the forward sequence when the plurality of sequences are drawn on the display area of the two-dimensional screen
S: Sum of integrals of each series
m is the number of series
The entropy formula is

The three-dimensional line graph viewpoint control program according to claim 8.

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