JPH11134520A - Three-dimensional shape data processor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To adjust a spatial frequency, i.e., a range wherein it is considered that there is one projection or recessed part by regarding a three-dimensional surface between points on a calculated outline as a smoothed curved surface and extracting feature quantities from the shape. SOLUTION: For mapping, viewer coordinates (x, y, z) are converted into polar coordinates (r, θ, ϕ) to convert the coordinates of vertexes of solid model data into the polar coordinates. Mapping data are given by regarding the intersection Pb of the straight line passing a point Pa on a solid model Pb from the origin O with a spherical surface S as a point corresponding to a point Pa on the solid model. Those Pa and Pb are value (r) different and the values and ϕ match each other. Namely, when the vertexes of the solid model data are converted to the polar coordinates, angular components θ and ϕ are mapping data on corresponding points on the spherical surface as they are. Thus, the solid model surface surrounded with the line of intersection of a range on a cylinder prescribed with the value obtained from the spatial frequency and the solid model surface is regarded as a smoothed curved surface to calculate features quantities.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a three-dimensional shape data processing apparatus for analyzing the physical properties of a measurement target using the three-dimensional shape data of the measurement target, and more particularly to a characteristic quantity such as a curvature of the surface of the measurement target. Is calculated.

[0002]

2. Description of the Related Art In recent years, in order to examine the physical properties of a three-dimensional measurement object, the measurement object is measured by measuring the spatial position of a plurality of points (apex) constituting the measurement object using a range finder or the like. Acquired as three-dimensional shape data, and analyzing the three-dimensional shape data using a mathematical method is performed.

In the analysis of such three-dimensional shape data, the three-dimensional shape data is represented by a point group whose position is spatially specified. At first glance it is hard to understand. Therefore, it is necessary to obtain a characteristic amount representing a shape such as a curvature or a differential value of the surface of the three-dimensional shape and quantitatively evaluate the characteristic amount. Conventionally, when a feature amount such as curvature is obtained from three-dimensional shape data, the feature amount at the noted vertex is calculated using a mathematical approximation formula by using the vertex coordinates of interest and the coordinates of the vertices around it. It was calculated.

[0004]

However, in the three-dimensional shape data, the interval between adjacent vertices necessarily varies depending on the shape of the object to be measured and the method of measurement. Specifically, when measuring the shape with a range finder, the measurement target is measured at equal intervals from one direction, so sampling is performed based on the difference between the optical axis direction of the range finder and the normal direction of each point on the measurement target surface. There is a difference in the distance between the two points. For example, as shown in FIG. 45, when the measurement object X is sampled at equal intervals to the right by irradiating the light of the range finder from below, the distance between the sampling points Pa and Pb and the distance between the sampling points Pc and Pd are measured. The distance will be greatly different.

[0005] When such a variation occurs, a feature value in a region having a high vertex density is calculated taking into account only a very narrow range, and a feature value in a region having a low vertex density has only a very wide range. For example, the considered value is calculated. That is, the calculation accuracy of the characteristic amount differs for each part of the three-dimensional shape. this is,
In other words, it can be said that the spatial frequency of the unevenness of the three-dimensional surface with respect to the region is at a different level in each portion.

[0006] Further, the feature amount is greatly affected by the level of unevenness of the three-dimensional shape data. Explaining two-dimensionally for the sake of convenience, for example, the outline of a part of a cross section of the captured three-dimensional shape data X includes a fine irregular component as shown in FIG. Let's say that the curve is Excluding the high frequency components of the spatial frequency from this contour, a smooth curve as shown in FIG. For example, when a differential value is obtained as a feature value at the point A of the same portion in these two contours, a clearly different value is obtained. Further, when the measurement target itself has small irregularities on the surface, the user may want to calculate a macroscopic curve ignoring the small irregularities, that is, a feature amount at a small level of the spatial frequency, or conversely, There is also a case where it is desired to calculate a microscopic curve for the unevenness, that is, a feature amount at a large level of the spatial frequency.

However, if the feature amount is calculated using only the target vertex and its surrounding vertices as in the prior art, the range for calculating the feature amount is fixed for each part. Only a feature amount at a spatial frequency level can be calculated, and a feature amount according to the unevenness level cannot be calculated flexibly. Therefore, the present invention provides a three-dimensional shape data processing apparatus capable of adjusting a spatial frequency, in other words, adjusting a range in which one convex or concave part is considered to be present, when calculating a feature amount from three-dimensional shape data. The purpose is to provide.

[0008]

According to the present invention, there is provided a three-dimensional shape data processing apparatus for calculating a feature quantity representing a shape of a three-dimensional shape surface represented by three-dimensional shape data. Distance obtaining means for obtaining the size of the area, range calculating means for calculating a plurality of points on the contour of the surface of the three-dimensional shape within a range defined by the obtained distance, and points on the calculated contour And a feature value calculating unit that calculates a feature value from the curved surface shape by regarding the three-dimensional surface in between as a smoothed curved surface.

[0009] The distance acquiring means may acquire the distance by calculating the distance based on vertex data constituting three-dimensional shape data. Also,
The distance obtaining means may obtain the distance by receiving a distance specified by a user.
The feature amount may be a curvature.

Further, the range calculating means includes a target point obtaining unit for obtaining a measurement target point on the three-dimensional shape surface, and the three-dimensional shape surface within a range of the obtained distance around the measurement target. It is preferable that the feature point calculation unit calculates a feature amount at the measurement target point acquired by the target point acquisition unit.

[0011]

Embodiments of the present invention will be described below with reference to the drawings. (1) System Configuration FIG. 1 is a functional block diagram showing the internal configuration of the three-dimensional shape data processing apparatus according to the present embodiment. As shown in the figure, the three-dimensional shape data processing apparatus includes an optical measurement unit 1,
It comprises a measurement object modeling unit 2, a disk device 3, a display 4, a mouse 5, a keyboard 6, a GUI system 7, a main module 8, and a measuring module 9.

The optical measuring section 1 is disclosed in, for example, Japanese Patent Laid-Open No. 7-174.
A device such as a range finder described in No. 536, which has a laser measuring device and optically reads an object to be measured. The measurement object modeling unit 2 models the optically read measurement object into a three-dimensional model. FIGS. 2A and 2B show the relationship between the three-dimensional model and the measurement object. FIG. 2A shows a part of a human body as an example of a measurement target. A plurality of points on the surface to be measured are irradiated with a laser by the optical measuring unit 1, and the positions on the spatial coordinates of each point are read. Using the position data read in this way, the measurement object modeling unit 2
Converts a measurement object into a three-dimensional model as shown in FIG. A three-dimensional model (three-dimensional shape model) is a model based on polygon mesh data that represents a measurement target by approximating a polyhedron, and is composed of thousands and tens of thousands of planes.

The circle in y201 shown in FIG.
The part surrounded by the circle y200 of the three-dimensional model of FIG. Each plane constituting the three-dimensional model is called a polygon mesh and has a triangular or quadrangular shape. Note that there is a place in the y201 of FIG. 2C where no stereo model data has been generated. This is a defective portion caused by defective reading of the reflected light from the optical measurement unit.

FIG. 3 shows the data structure of the three-dimensional model. The data representing the three-dimensional model includes a combination of the total number of vertices and the total number of polygon meshes, a polygon mesh list, and a vertex list. The vertex list contains an identifier assigned to each vertex,
5 is a list showing three-dimensional coordinates of each vertex. The polygon mesh list is a list indicating identifiers assigned to the respective polygon meshes, the number of vertices forming the respective polygon meshes, and identifiers of the respective vertices forming the polygon mesh.

The arrangement order of the identifiers of the vertices constituting each polygon mesh in the polygon mesh list is such that the three-dimensional model is counterclockwise when viewed from the front side. In addition, the inside and outside of the three-dimensional model can be identified. The disk device 3 stores a large number of data files containing three-dimensional model data.

The display 4 has a spacious display surface of 20 inches or more, on which a number of windows can be arranged. "VIEWER", "CANVAS",
There are three types, such as "panel". The viewer is a window for displaying three-dimensional data, the canvas is a window for displaying two-dimensional data, and the panel is a window for displaying various operation buttons and measured values.

In the display of the viewer, the surface can be shaded by a rendering process, and a pattern / pattern can be attached by a texture mapping process. In addition to a window, a goggle type three-dimensional display having a liquid crystal shutter, real-time holography, or the like can be used for displaying the viewer.

FIG. 4 shows a display example of the display 4. In the figure, the display surface of the display 4 has three viewers y2201 to y2203 and four canvases y22.
04 to y2207 and two panels 70 and 90 are arranged. The viewer y 2201 displays a perspective image of the three-dimensional model data, the viewer y 2202 displays a side image, and the viewer y 2203 displays a top image of the three-dimensional model data. Canvas y2204-y
In 2206, a cross-sectional image obtained by cutting the three-dimensional model data is displayed. The reason why a plurality of canvases are arranged in this way is to individually display a plurality of cross sections of the three-dimensional model such as a neck circumference, a waist circumference, and a chest circumference of the three-dimensional model.
The panel displays the cross-sectional area information and distance information of the three-dimensional model, the measuring processing operation panel for inputting the user's instruction, the display of the feature value in the curved surface mode, and the input of the user's instruction. Panel for curved surface mode processing.

FIG. 5 shows the correspondence between the coordinate system of the viewer and the coordinate system of the canvas. FIG. 5 (b)
, The coordinates of the viewer system have the origin at the lower left of the three-dimensional model data. On the other hand, the coordinate system on the canvas has the origin at the center of a virtual plane called a reference plane, and forms a coordinate system based on the X axis and the Y axis set on this plane. This reference plane is a virtual plane used by the user to specify which part of the three-dimensional model to measure and repair, and is displayed together with the three-dimensional model in the viewer. The polygon mesh on the front side of the reference plane has a positive coordinate value on the Z coordinate, and the polygon mesh on the back side has a negative coordinate value on the Z coordinate.

The reference plane will be described with reference to FIGS. As shown in FIG. 6A, the X, Y, and Z axes of the canvas coordinate system are orthogonal to the center position of the reference plane. The orthogonal point is the origin in the canvas coordinate system. These X axis, Y axis, and Z axis are displayed together with the reference plane, and
Each axis is set to a different color so that it can be easily distinguished, and further, the positive portion and the negative portion have different colors.

The reference plane shown in FIG. 6A is represented by a data structure shown in FIG. That is, the reference plane is composed of a normal vector (p, q, r), coordinates (Xa, Ya, Za) of the center position expressed in the viewer coordinate system, a vertical width LX, and a horizontal width Ly.
Are represented by a data structure in which In the viewer coordinate system, p (X−Xa) + q is between any coordinate (X, Y, Z) on the reference plane and the normal vector (p, q, r).
The relationship of (Y−Ya) + r (Z−Za) = 0 holds.

The reference plane has six degrees of freedom (position and orientation in a three-dimensional space). That is, as shown in FIG. 7A, the posture of the reference plane is changed in the X-axis and the Y-axis in accordance with the operation of the user.
It rotates in the directions of arrows Rx, Ry, and Rz around the Z axis, and as shown in FIG. 7B, the position of the reference plane is the arrow mx, m of the X axis, the Y axis, and the Z axis.
It slides in the y and mz directions. The mouse 5 and the keyboard 6 are input devices for specifying a position in the canvas or the viewer, indicating buttons set on various panels, and inputting numerical values.

The GUI system 7 manages events, and controls the allocation of canvases and viewers on the display 4 and the allocation of various menus. The main module 8 is an executable program that describes the procedure of the main routine.
Is an executable program that describes the procedure of measuring processing and other processing branched from the main routine. These modules are loaded onto the memory from the disk device 3 and executed by the processor 10 one by one.

The processor 10 is an integrated circuit having a decoder, an ALU, and various registers.
Various three-dimensional data processing is controlled based on the contents of the measuring module 9. Note that the three-dimensional data processing device may be implemented by using a normal computer capable of inputting data of the optical measurement unit 1 and incorporating a program that causes the computer to perform the following operations and functions. The program can be realized, and the program can be recorded on a recording medium readable by the computer, such as a CD-ROM.

(2) Outline of Control Operation Next, control contents of the processor based on the main module 8 will be described with reference to a main flowchart of FIG. First, in step 10, the processor 10
Performs initialization such as hardware initialization and display of various windows. After the initial setting, the display 4 displays a POPUP menu for asking the user whether to execute the three-dimensional model data capturing process, the measuring process, or other processes. Here, if the user selects the three-dimensional model data import process, step 11 becomes Yes and the process proceeds to step 12.

In step 12, the processor 10 activates the optical measuring section 1, irradiates the object to be measured with a laser beam by the optical measuring section 1, and measures the reflected light. After the laser irradiation, the measurement target modeling unit 2 is caused to generate three-dimensional model data based on the measurement result. Thereby, the three-dimensional model data as shown in the explanatory diagram of FIG. 2 is generated. When the three-dimensional model is generated in this way, in step 17, the processor 10 displays the generated three-dimensional model data on the viewer. By step 17, the display is
The screen will look like the display example shown in FIG. The cursor position on this screen is appropriately moved by the event management of the GUI system 7.

The user can measure the three-dimensional model data,
When the restoration process is selected, step 13 becomes Yes and the process proceeds to step 14. The details of this processing will be described later. If the user selects a process other than these, S1
5 is Yes, the process proceeds to step 16, and the processor 1
A value of 0 causes processing such as data deletion and conversion, and processing such as rotation and movement of the three-dimensional model.

(3) Measuring Process Next, the contents of the measuring process of FIG. 8 will be described in detail. FIG. 9 shows a main flowchart of the measuring process. When the process shifts to the measuring process, the display 4 displays a measuring process operation panel 70 as shown in FIG. In the measuring process, various modes are activated in response to clicking a button on the measuring process operation panel 70 shown in the figure.

As shown in FIG. 10, the measuring processing operation panel 70 has the following buttons for accepting a user's instruction and activating various modes. That is, (1) a cutting mode start button 71 for starting a cutting mode for virtually cutting the three-dimensional model by the reference plane and calculating the cross-sectional area and perimeter of the cut surface, and (2) between two points of the three-dimensional model. Mode start button 72 for activating a distance mode for obtaining the distance of the object or the path length on the surface, (3) surface mode activating button 73 for activating a surface mode for obtaining a feature amount of the three-dimensional model surface, (4) A restoration mode activation button 74 for activating a restoration mode for automatically restoring a missing portion of the three-dimensional model is provided.

Further, as a button for receiving a user's instruction, a reference plane moving button 76 for moving the reference plane, a reference plane rotation button 77 for rotating the reference plane, and a three-dimensional model for loading the three-dimensional model It has a load button 78 and a measuring process end button 79 for ending the process. Further, in order to display measurement results and the like to the user, a model size display unit 81 indicating the size of the shape model in the X, Y, and Z directions in the viewer coordinate system, and a cut surface of the three-dimensional model cut into the reference plane. Section information display sections 82 and 2 for displaying the perimeter and the sectional area
Distance information display section 8 for displaying the straight-line distance between points and the path length
Three.

The user operates the mouse and keyboard,
The cursor is moved to each button on the measuring processing operation panel 70 to input an instruction. Here, when an event is input by a button operation of the user, the process shifts to a series of determination steps from step 31 to step 36, and the determination is sequentially performed until “Yes” in any of the steps.

(3-1) Reference plane display processing The reference plane display processing is executed via step 31 in FIG. 9 when the reference object is not displayed on the viewer. When the three-dimensional shape data processing device is activated,
Since the reference plane has not been displayed, the routine normally proceeds to step 31 to perform the reference surface treatment. The main purpose of this reference plane display process is to display the reference plane by adjusting the reference plane to the size of the three-dimensional model.

How the matching with the three-dimensional model is performed will be described with reference to the flowchart of FIG. First, in step 101, the maximum value and the minimum value of the X coordinate, Y coordinate, and Z coordinate are searched from the vertex list shown in FIG. In step 102, the size of the three-dimensional model in each of the XYZ directions is calculated from the searched maximum value and minimum value. Since the maximum value and the minimum value of the coordinates of the vertices have already been searched in step 101, the vertical size and the horizontal size of the three-dimensional model data are calculated based on these. The calculated sizes are displayed on the model size display section 81 on the measuring operation panel 70 shown in FIG.

After execution of step 102, step 103
In, the processor 10 determines the size of the reference plane to match the calculated vertical size and horizontal size of the three-dimensional model. Here, one side of the reference plane is defined as X of the three-dimensional model.
The length is obtained by multiplying the maximum value of the size in each of the YZ directions by 1.1 times. After execution of step 103, step 104
The processor 10 calculates the range occupied by the three-dimensional model data using the maximum value and the minimum value of the X coordinate, the Y coordinate, and the Z coordinate, and calculates the center position thereof. The position calculated here is the center position of the reference plane. When step 104 is completed, in step 105, the processor 10 sets the reference plane at the midpoint position in the viewer. Finally, the reference plane is displayed on the viewer in a state where it is set at the center of the three-dimensional model data. At this time, the sign of each axis of the reference plane is displayed in different colors.

(3-2) Reference plane movement / rotation processing When the reference plane movement button 76 or the reference plane rotation button 77 of the measuring processing operation panel 70 is operated by the user, the reference plane is moved from step 32 in FIG. Move to the movement / rotation processing. The reference plane is for the user to specify which part of the three-dimensional model is to be measured and repaired, and the displayed reference plane is moved and rotated according to the user's intention. FIG. 12 shows a flowchart of the reference plane movement / rotation processing.

The reference plane movement / rotation processing includes processing (1) for changing the attitude of the reference plane activated by the reference plane rotation button 77 and processing for changing the position of the reference plane activated by the reference plane movement button 76 ( 2) The amount of rotation in (1) and the amount of movement in (2) are determined by the amount of event input by the user. Here, the user inputs the event amount by using a rotation / movement amount input panel 90 displayed by clicking the reference plane rotation button 77 and the reference plane movement button 76 shown in FIG. Specifically, the user operates the rotation / movement input panel 90.
An input amount of each coordinate is designated by a cursor and a desired numerical value is key-typed to input an event amount.

In the reference plane moving / rotating process, first, at step 111, the amount of event input by the user is detected. The input event amount is displayed on the display units 91, 92, 93 for each coordinate. When the user clicks the confirm button 94, the displayed input value is confirmed and the event amount is accepted. The input of the event amount may use the rotation amount of the sphere built in the mouse 5 obtained by the running operation of the mouse 5.

Next, at step 112, it is determined whether or not the reference plane rotation button 77 has been clicked. Here, when the reference plane rotation button 77 is clicked, it is determined that the rotation amount has been input, and the process proceeds to step 113. In step 113, the processor 10 calculates the amount of rotation about each reference axis based on the amount of event detected in step 111. After execution of step 113, the process proceeds to step 114, and the reference plane is rotated around the reference axes by the calculated rotation amounts (see FIG. 7A). Finally, the process proceeds to step 118, where the reference object is displayed again based on the posture obtained by the rotation. Thereafter, the process returns to the main routine shown in FIG.

If No is determined in the step 112, the process shifts to a step 115 to determine whether or not the reference plane moving button 76 is clicked. Here, if the reference plane movement button 76 is in a clicked state, it is determined that the movement amount has been input, and the process proceeds to step 116. In step 116, the movement amount in each reference axis direction is calculated from the event amount input in step 111, and the movement amount calculated in step 117 is added to the origin coordinate value of the reference plane in the viewer coordinate system. That is, assuming that the center coordinate of the reference plane in the viewer coordinate system is (Xa, Ya, Za), the movement amount calculated in step 35 is newly added to this. By these processes,
The position of the reference plane slides freely according to the event amount (see FIG. 7B). Thereafter, the process also proceeds to step 57, where the reference object is displayed again at the moved position, and the process returns to the main routine shown in FIG.

By the above operation, the intersection angle between the reference plane and the three-dimensional model can be freely changed in accordance with the user's instruction, and by freely sliding the reference plane, the cutting position of the three-dimensional model can be changed. You can switch freely. (3-3) Cutting Mode Processing In the main flow of FIG.
Is operated, the flow shifts to the disconnection mode processing in step 40. FIG. 14 is a flowchart showing the cutting mode process. As shown in the flowchart of FIG. 14, in the cutting mode processing, the cross-section data of the three-dimensional model data with the reference plane as the cut plane is calculated in the cross-section data calculation processing in step 61, and the cross-section data calculated in the cross-section display processing in step 62 is calculated. A cross-sectional image is displayed on the canvas based on the image. Then, in the cross-sectional area measurement processing in step 63, the cross-sectional area is calculated based on the cross-sectional data, and step 64 is performed.
In the contour length measuring process, the contour length of the section is measured. Finally, in the cross-sectional area / contour length display step of step 65, the cross-sectional area and the contour length are displayed. Each of the above processes will be described in further detail below.

(3-3-1) Section data calculation mode “Cross section data” refers to the intersection between the reference plane and the three-dimensional model,
This is information expressing a cross section of the three-dimensional model by a line segment series connecting these intersections. Figure 1 shows the procedure for calculating the cross-sectional data.
5 to FIG. FIG.
In the flowcharts of FIGS. 5A and 5B, “section i” is a variable indicating each of a plurality of section data obtained on the reference plane. In the cross section data calculation process, first,
In step 201, the processor 10 converts the vertex coordinates of the polygon mesh into a canvas coordinate system. Then, in step 202, the process branches to the flowchart of FIG. FIG.
In step 301 of the flowchart of FIG. 5B, the process branches to the flowchart of FIG. 16 to perform the “connection process of intersections”, and in step 302, branches to the flowchart of FIG. 17 to perform the “connection process of line segment sequence”.

(3-3-2) Connection processing between intersections The “connection processing between intersections” shown in FIG. 16 calculates the coordinates of the intersection between the three-dimensional model and the reference plane, and connects the calculated intersections. Generate In the process of connecting the intersections, first, in step 403, the processor 10 has a negative product of the Z coordinates (here, the Z coordinates are the Z coordinates in the canvas coordinate system) for the combination of the vertex coordinates of one polygon. And if it is negative, a line segment connecting the vertex and XY
Find the intersection with the plane. That is, a negative product of the Z coordinate indicates that the vertices of the combination face each other via the reference plane. For example, when the positional relationship between the polygon mesh and the reference plane is as shown in FIG. 18A, among the combinations of the vertices of the polygon meshes P1, P2, P3, P4, and P5, combination 2601, combination 2602, combination Since the vertices of 2603 face each other via the reference plane, the z coordinate is inverted between positive and negative, and the product is negative. Therefore, the vertices of these combinations are connected by a straight line, and the coordinates of the intersection with the reference plane as shown by the mark “x” in FIG. When the above processing is completed for all the vertex combinations of the polygon mesh, a plurality of intersections can be obtained on the reference plane as shown in FIG.

Subsequently, in step 405, the processor 10 determines whether two intersections have been generated for one polygon, and if so, in step 406, the processor 10 generates a line segment connecting the intersections. For example, as shown in FIG. 19A, it is assumed that an intersection is obtained on the reference plane in the process of step 402. Intersection y270
1 and y2702 are both intersections of the polygon mesh P1 shown in FIG. 18, so that a line segment y2710 connecting these is generated as shown in FIG. 19B. Similarly, since the intersections y2702 and y2703 are also intersections of the polygon mesh P2, a line segment y2711 connecting these is generated.

(3-3-3) Linking Process of Line Segment Sequence When the connecting process of the intersections is completed, the process proceeds to the connecting process of the line segment sequence. The “line segment sequence” is a polygonal line for expressing a contour line of a three-dimensional model on a reference plane, and is generated by connecting line segments generated by a connection process between intersections. FIG. 17 shows a specific procedure of the “connection process of line segment sequence”. In this flowchart, “line segment i” is a variable for designating an individual line segment on the reference plane, and “line segment sequence i” is a variable for designating a line sequence including the line segment i. is there.

In the connecting process of the line segment sequence, first, in step 5
At 02, it is determined whether or not a line segment m having an end point that matches the end point coordinates exists for the line segment k. If such a line segment m exists, a line segment sequence i including the line segment k is detected, and the line segment m is converted to the line segment sequence i.
Connect to The above processing is performed for all the line segments k (k = 1, 2,...)
When repeated for n), for example, the line segment group shown in FIG. 19B becomes a polygonal line segment sequence on the reference plane as shown in FIG. 19C. Note that y in FIG.
2704, y2705, y2706, and y2707 are not connected by a straight line. This is the result of the missing part appearing on the reference plane.

(3-3-4) Cross-Section Data Judgment Processing When the “connection processing of the line segment sequence” is completed, the process proceeds to step 303 in FIG. 15B, where all cross-sections i are closed or opened. Is determined. In step 305, the processor 10 determines whether or not the start point and the end point of the line segment sequence for the cross section i are the same or within a predetermined distance. If so, the process proceeds to step 306, where this is regarded as a closed section, and the section flag Fi is set to 0 indicating that the section is closed for the section i. On the other hand, the intersection y2704-intersection y270 in FIG.
5. If the start point and the end point of the line segment sequence are separated by a predetermined distance or more, such as between the intersection point y2706 and the intersection point y2707, the nearest line segment sequence is searched in step 307. If the search finds a line segment sequence, in step 308 the processor 1
A value of 0 determines whether the distance from the line segment is longer than a predetermined value. If the line segment is not opened by more than the predetermined value, the line is connected to the line segment sequence and the process returns to step 305 again. On the other hand, if the opening is not less than the predetermined value, the process proceeds to step 310 and the section flag Fi for the section i is set to 1 indicating that the section is open. When the above processing is completed for all the cross sections i (i = 1, 2,... N), step 203 in FIG.
Return to In step 203, the vertices of the cross-section data are converted to a canvas coordinate system. After the execution of step 203, the process proceeds to step 204 to create a contour of a cross section.

(3-3-5) Cross-Section Display Processing In the cross-section display processing in step 62 of FIG. 14, a contour line represented as a connected body of line segments is displayed on the canvas as a cross-section image. In this display, the display is changed depending on whether the outline is a closed cross section or an open cross section with reference to the cross section flag Fi. That is, if Fi = 0 and the contour is a closed cross section, the cross section of the cross section is painted in “light green” and displayed on one of the canvases. This filling is easily realized by a color conversion algorithm realized in an existing graphics system. On the other hand, if the contour line is open when Fi = 1, only the intersection line indicating the cross section is displayed in "yellow". This is because if you try to fill the inside of the section where the outline is open with the above color conversion algorithm, the part outside the section will be filled by mistake, and only the intersection line of the reference plane is drawn with a different color. It is something to keep.

(3-3-6) Cross-Section Area Measurement Processing In the “cross-section area measurement processing” of step 63 in FIG. 14, the cross-sectional area on the reference plane is calculated by polygon approximation. That is, when the intersections forming the cross section as shown in FIG. 20A are calculated, the area (Sum1, Sum2, Sum3) of the triangle formed by the adjacent intersection and the origin as shown in FIG.・
・ ・) Is calculated to calculate the cross-sectional area. The area of each triangle is calculated based on the cross product of vectors from the origin to the adjacent intersection. If the origin is located outside the cross section, the area of the triangle formed by the vector tangent to the outside of the cross section is a negative value, and the area of the triangle formed by the vector tangent to the inside of the cross section is By setting it to a positive value, the cross-sectional area can be obtained.

(3-3-7) Contour Length Measurement Processing In “contour length measurement” in step 64 of FIG. 14, the contour length of the cross section is calculated by approximating it to the broken line length (line segment length). For example, when the intersection is obtained as shown in FIG.
Sum of each line segment composed of adjacent intersections (Len1 + Len2 +
Len3 + Len4 + ...) calculates the contour length. If the cross section is open, the distance between the start point and the end point of the contour is added to the contour length Len.

When the above processing is completed, the cross-sectional area and the contour length calculated in step 65 of FIG. 14 are displayed on the cross-section information display section 82 of the measuring processing operation panel 70 with four significant digits to execute the cutting mode processing. Finish. (3-4) Distance Mode Processing In the flowchart of FIG. 9, when the distance mode start button 72 of the measuring processing operation panel 70 is operated, the processing shifts to the distance mode processing of step 41. In the distance mode processing, a desired distance in a three-dimensional space where the three-dimensional model data is placed is measured.

Here, it is assumed that the linear distance between two points in the three-dimensional model and the length of a path passing on the surface of the three-dimensional model are measured. The processing is performed for two types of path lengths that do not exist on one plane. FIG. 21 is a flowchart showing the distance mode processing. First, when the distance mode is activated, the selection panel 130 shown in FIG. On the selection panel 130, a two-point mode button 131 for starting a two-point mode for setting a mode for obtaining a straight line distance between two points, and a three-point mode for obtaining a path length existing on one plane of the three-dimensional model surface are started. A three-point mode button 132, an N-point mode button 133 for starting an N-point mode for finding a path length that does not exist on one plane of the three-dimensional model surface, and a cancel button 134 for ending the processing are provided. Next, in step 602, the process waits for the mode to be input to the selection panel 130, and shifts to processing according to the input mode.

(3-4-1) Two-Point Input Mode Processing When the two-point mode button 131 is operated from the selection panel 130, in step 604, the two points of the start point and the end point are determined in order to obtain the linear distance between the two points. It is determined whether or not a point has been input. If not, the process waits for an input in step 605. In this mode, the user inputs a point by clicking a point on the surface of the three-dimensional model displayed on the viewer or by clicking on a point on the contour displayed on the canvas.

When the input of two points is received, the process shifts to the main routine, and returns to step 604 again. Here, since two points have been input, the distance between the two points is calculated from the coordinate values of the two points in step 606, and the distance information display section 83 of the measuring processing operation panel 70 is calculated in step 607.
Displays the calculated value. (3-4-2) Three-Point Input Mode Processing When the three-point mode button 132 is operated from the selection panel 130, the process shifts to a three-point input mode for obtaining the path length on one plane of the three-dimensional model surface from step 608. . Here, three inputs are determined first, and if not, the input of three points of the three-dimensional model is waited. In the three-point mode, the user can click the start point, end point, and passing point on the contour line of the cross section displayed on the canvas, or start, end, and passing points on the surface of the three-dimensional model displayed in the viewer. This is done by clicking.

The input of these three points will be specifically described below. First, when inputting from the outline of the cross section displayed on the canvas, the user clicks two points that are the start point and the end point on the outline of the cross section displayed on the canvas. For example, a cross section 4 as shown in FIG.
Assuming that 0 is displayed on the canvas, the user inputs a start point and an end point by clicking points 41 and 42 on the outline of the cross section. When the start point and the end point are input, the path with the two points as the start point and the end point is a path 44a and a path 44b.
It becomes two. Therefore, the user finally clicks the point 43 as a passing point to select any one of these routes. Note that the route may be selected by a method such as clicking the area on the side where the route exists instead of the passing point.

Next, when inputting three points of the three-dimensional model displayed in the viewer, the user clicks three points on the surface of the three-dimensional model displayed in the viewer in the order of the start point and the end point. . For example, for a three-dimensional model 32 as shown in FIG. 24A, a point 51 is input as a start point, a point 52 as an end point, and a point 53 as a pass point as shown in FIG. The input from the canvas and the input from the viewer are distinguished depending on whether the user has input the first point from the canvas or the viewer.

When the input of three points is completed, the process returns to the main routine and returns to step 609 again. In this case, since three points have been input, the processing shifts to the next processing.
Steps 611 to 613 are processing for obtaining a cross section passing through three points. However, when three points are input from the canvas, since the cross section has already been obtained, the processing in these steps uses the obtained values as they are. I do.

When three points are input from the viewer's three-dimensional model, in step 611, the direction and position of a reference plane passing through the three points are calculated. When three points are designated as shown in FIG. 24B, first, as shown in FIG. 24C, a straight line connecting the point 51 which is the start point and the point 52 which is the end point is set as the X axis of the reference object. The direction and position of the reference plane are determined by setting the middle point between the two points as the origin and the plane passing through the X axis and the point 53 as the passing point as the XY plane.

Next, a reference plane is displayed on the viewer in accordance with the direction and position obtained in step 612.
Then, in step 613, the cut surface of the three-dimensional model by the reference plane is calculated. The method of calculating the cut surface is the same as that of the cutting process. When the cut surface is determined, FIG.
It is displayed on the canvas as shown in (d). When the above processing is completed, the path length is calculated in step 614 regardless of the three-point input by the canvas or the three-point input by the viewer. The calculation of the path length is easily performed by integrating the line segment length from the start point to the end point through the passing point. The path length measurement processing will be described with reference to the flowchart in FIG. In this flowchart, the “path length Len” is a variable for storing the length of a path including a start point, an end point, and a passing point. When the process proceeds to the flowchart, the processor 10 initializes the path length Len in step 651 by substituting 0 for the path length Len.

Subsequently, in step 652, the processor 10 obtains a line segment sequence including a start point, an end point, and a passing point. Then, control is passed to step 653, and control is performed so that the process of step 654 is repeated from the start point to the end point. In step 653, the processor 10 calculates the distance between the combinations and adds it to the path length Len. When this process is repeated for all the intersections from the start point to the end point, a path length passing through the three designated points is obtained.

When the path length is calculated, the process proceeds to step 615, where the specified path is displayed in a color thicker and different from the line forming the normal cross section (FIGS. 23 (c) and 24 ( d)). Finally, the value calculated in step 614 is displayed on the distance information display section 83 of the measuring processing operation panel 70. (3-4-3) N-Point Input Mode Processing In the N-point input mode, processing is performed to obtain a path length that is not on one plane of the surface of the solid model. As a means for specifying a route that is not on one plane, dragging the mouse on the surface of the object may be considered, but it is difficult for the user to accurately drag the route on the surface of the three-dimensional model on the two-dimensional screen. Here, a route is specified by a plurality of points on the three-dimensional model. The user specifies N points including a start point, an end point, and a plurality of passing points.

The N point on the three-dimensional model usually does not exist on one plane. Therefore, there are countless paths passing through the N points, and it is difficult to specify the paths. Therefore, here, N
3 points are extracted from the points, and the obtained 3 points are
The path length passing through three points is calculated by the method used in the point input mode, and the path length passing through N points is approximately obtained using the result.

A specific description will be made with reference to FIG. For example, as shown in FIG. 26A, four points P1, P2, P3, P4 (P1 is a start point, P4 is an end point, P2, P3
Is a passing point). Where point P
Using three points of P1, P2, and P3 to determine a route from a plane passing through the three points, points P1 and P3 shown in FIG.
2. A path through P3 is obtained. Where P
1, the distance between P2 is La12, and the distance between P2 and P3 is La23.

Next, using the three points P2, P3 and P4,
When a path is obtained from a plane passing through the three points, a path passing through points P2, P3, and P4 as shown in FIG. 26C is obtained. Here, the distance between P2 and P3 of this route is Lb23, and the distance between P3 and P4 is Lb34. Note that La12, La23, Lb23, L
The path length of b34 can be obtained by the same method as in the three-point input mode.

In this case, there are two paths passing through the points P2 and P3, a path having a length La23 and a path having a length Lb23. Therefore, here, the route to be sought is 2
La23, Lb23
Is the length of the path passing through the points P2 and P3. That is, 4
The length of the path passing through the points P1, P2, P3, and P4 is La12 + ((L
a23 + Lb23) / 2) + Lb34.

By further generalizing this, the path length by designating N points of P1, P2,.
Let ath (P1, P2,... PN) be obtained. The path length between the starting point and the passing point is represented by L (Pi, Pi + 1, Pi) for the path length obtained from a plane passing through three consecutive points Pi, Pi + 1, and Pi + 2 as the starting point, the passing point, and the ending point. +2, "former"), and the path length between the passing point and the end point is L (Pi, Pi + 1, Pi +
2, "latter").

The distance between the start point P1 of the entire route and the next point P2 and the distance between the end point PN and the point PN-1 just before the end point of the entire route are uniquely determined. Other points Pi between points,
The path length of Pi + 1 (i = 2, 3,..., N-2) is L (P
i, Pi + 1, Pi + 2, “former”) and L (Pi + 1, Pi + 2, Pi +
3, “latter”). As a result, the path length Pa
th (P1, P2, ... PN) is

[0067]

(Equation 1)

Can be expressed as Next, a description will be given of what operation is performed to actually perform the path length passing through the N point. When the N-point mode button 133 is operated on the selection panel 130 to enter the N-point input mode for performing the above-described processing, the processing shifts to Step N608 in FIG. First, at step 618, it is determined whether or not N points have been input. If the N point has not been input, the flow shifts to step 619 to wait for the N point input.

The input of points is performed by the user clicking on the surface of the solid model in the viewer. When the user clicks the first point on the surface of the three-dimensional model, FIG.
A pop-up menu 150a for prompting the user to specify the next point as shown in FIG. Subsequently, when the user designates the second point and the third point, the pop-up menu 150a shown in FIG. 27A is displayed.

By the way, in the N-point input mode, if there are four or more points, points can be specified without limitation, and it is necessary to indicate that the user has finally input all points. Therefore, after inputting the fourth point, each time a point is input, a pop-up menu 15 asking whether to end N-point input or to input another point as shown in FIG.
0b is displayed. Here, the user clicks the finish button 151 when the input of the desired N points is completed, and clicks the continue button 1 when the input is still continued.
Click 52. When the user clicks the finish button 151, the input of the N points is completed, and the coordinate values of each point in the viewer coordinate system are input.

When the input of the N points has been accepted, the process returns from the main routine to step 618 again.
Move to 0. At step 620, the processor 10 divides the path. Specifically, a set of three consecutive points from the input N points is extracted while shifting one point at a time. Subsequently, a cross section is calculated for a set of three points extracted in step 621, and a path length is calculated in step 622. In this process, a reference plane passing through three points is obtained, a cut plane is derived from the reference plane, and a path length between the points is obtained from the cut plane. The same calculation as the calculation method performed in the three-point input mode process is performed. Is sufficient.

After performing the above processing of steps 621 and 622 for all sets of three points, the total path length is calculated by the above equation in step 624. Then, in step 625, a path for inputting N points is displayed. Here, it is assumed that the displayed route displays a line segment connecting each of the N points with a straight line. Needless to say, various displays are possible, such as calculating a curve connecting the N points smoothly and displaying the calculated curve.

Finally, at step 626, the processor 10 displays the path length calculated at step 624 on the distance information display section 83 of the measuring processing operation panel 70, and ends the N-point input mode processing. As described above, N
In the point input processing, an arbitrary path length on the surface of the three-dimensional model can be calculated. Note that, here, the distance between two points whose two path lengths were calculated was obtained by calculating the two path lengths. However, the distance between the two points of each curve was defined as the overlapping portion of the two paths. Various methods can be employed, such as calculating a path length by linearly complementing with a weight and obtaining a curve. Here, three consecutive points out of N points are 1
Three points were extracted by grouping while shifting each point. However, it is sufficient if two of the three points are grouped so as to share another group. For example, for points Pa, Pb, Pc, and Pd, Therefore, it is also possible to make a grouping such as (Pa, Pb, Pd) and (Pa, Pb, Pd).

(3-5) Surface Mode Processing In the surface mode processing, characteristic values such as differential values and curvatures are obtained for points and surfaces on the surface of the three-dimensional model designated by the user, and these characteristic values are displayed as numerical values and images. In calculating the feature amount, the level of the unevenness of the three-dimensional model, that is, the spatial frequency of the unevenness of the three-dimensional model is set and adjusted. This curved surface mode process shifts via step 35 when the curved surface mode start button 73 of the measuring process operation panel 70 is clicked in the flowchart of the measuring process of FIG. FIG. 28 shows a flowchart of the curved surface mode processing. Hereinafter, the curved surface mode processing will be described separately according to this flowchart into spatial frequency adjustment processing and feature quantity calculation processing.

(3-5-1) Adjustment of Spatial Frequency Adjustment of the spatial frequency removes high-frequency noise generated when measuring an object to be measured, alleviates unevenness in the distance between sampling points, and allows the user to adjust the spatial frequency. The spatial frequency is adjusted in consideration of, for example, a case where it is desired to obtain a feature amount macroscopically or microscopically from the model. Note that the spatial frequency here refers to the period of the physical unevenness per unit length, and the adjustment of the spatial frequency refers to specifying how much unevenness is to determine the feature amount. . From a different point of view, one reciprocal of the spatial frequency represents the distance of one period of the unevenness, so that it can be said that the range in which one convex portion or one concave portion is formed is adjusted.

More specifically, designation of a spatial frequency,
That is, by specifying the distance, for example, the three-dimensional model surface portion Sxa in the intersection of the three-dimensional model X and the range represented by the cylinder C having a diameter of the distance d defined by the reciprocal of the spatial frequency shown in FIG. The part is regarded as a smoothed surface Sxb as shown in FIG. 29B, and the feature amount of the three-dimensional model surface Sxa is calculated. In the actual calculation, it is not necessary to find the line of intersection between the range and the surface of the three-dimensional model, and it is sufficient if there are several points on the line of intersection.

In the flowchart of FIG. 28, if a curved surface mode processing panel described later is not displayed, step 7 is executed.
Moving to the 02 side, the spatial frequency is adjusted. Normally, immediately after the curved surface mode is activated, the curved surface mode processing panel is not displayed, and the process proceeds to step 702. Step 702
In, the reference value of the spatial frequency is calculated. This is to determine an appropriate spatial frequency for calculating the feature amount according to the average of the distance between the points constituting the three-dimensional model. The reference value of the spatial frequency is calculated based on the distribution density of the vertices of the three-dimensional model. FIG. 30 is a flowchart showing a process for calculating the reference value of the spatial frequency. In calculating the reference value of the spatial frequency, first, in step 802, the average value avr (1 / Lside) of the reciprocal of the vertex of the three-dimensional model is obtained. This is the average value of the spatial frequency with one cycle between vertices. Next, at step 803, the reference value of the spatial frequency is calculated by multiplying the obtained average value by the correction value Vfrag to avr (1 / Lside). Vfrag is a value obtained experimentally or empirically. Here, Vfrag = 0.25 is used. Note that the reference value of the spatial frequency is not limited to the case where the reference value is obtained from the distribution density of the vertex group. For example, the reference value of the spatial frequency on the surface of the three-dimensional model that has the largest band can be selected.

When the reference value of the spatial frequency is determined, step 7
At 03, the value is stored in the predetermined storage area, and the curved surface mode processing panel 140 is displayed. This curved surface mode processing panel 140 displayed in step 704 is shown in FIG. The curved surface mode processing panel 140 includes the slider 1
41, spatial frequency display section 142, feature selection button 1
44, 145, 146, differential direction selection button 147, calculated value display section 148, point mode start button 149,
It comprises an area mode start button 150, a mapping mode start button 151 and an end button 152.

The slider 141 is used by the user to adjust the spatial frequency. The slider 141 is moved left and right by using a mouse so that the value of the spatial frequency is set to 10 with respect to the calculated spatial frequency reference value. It can be changed at a magnification from -3 to 103. Spatial frequency display section 142
Displays the value of the spatial frequency obtained according to the adjustment amount of the slider. At first, the reference value of the spatial frequency calculated in step 702 is displayed.

Buttons 144, 145, 14 for selecting feature values
Reference numeral 6 denotes a button for selecting a feature amount to be calculated by the user. Here, an average curvature can be selected by a feature amount selection button 144, and a Gaussian curvature can be selected by a feature amount selection button 145. The differential value can be selected using the feature amount selection button 146.
When a differential value is selected as a feature value, a differentiation direction is selected by a differentiation direction selection button 147.

The point mode start button 149 is a button for starting a point mode for obtaining a feature amount of one point on the three-dimensional model. The feature amount obtained here is displayed on the calculated value display section 148. The area mode activation button 150 is a button for activating an area mode in which feature amounts are calculated for all points when the three-dimensional model is viewed from one direction, and the result is displayed as an image. The mapping mode activation button 151 is a button for activating a mapping mode in which feature amounts are calculated for all points on the surface of the three-dimensional model, and the result is attached as an image to the three-dimensional model by a texture mapping process. The end button 152 is a button for ending the curved surface mode.

(3-5-2) Feature Amount Calculation Process When the curved surface mode processing panel 140 is displayed, the main routine shifts to step 702 again, and shifts to the next feature amount calculation process. In the feature amount calculation processing, processing in the point mode, the area mode, and the mapping mode is performed according to the operation content of the surface mode processing panel 140, and any one of a differential value, an average curvature, and a Gaussian curvature is obtained as the feature amount. . The average curvature indicates to which side the curved surface bulges. The Gaussian curvature indicates whether a curved surface can be formed by bending a plane, and the value does not become 0 in the case of a curved surface requiring expansion and contraction in addition to bending of a plane. The feature amount depends on the normal direction of the location to be measured, and there is a feature that does not depend on the coordinate system determined by the normal direction according to the feature amount,
The coordinate system defined by the reference plane is properly used.

(3-5-2a) Calculation of Differential Value Since the differential value can be calculated regardless of the normal direction of the measurement point, a coordinate system determined by a reference plane is used. This coordinate system is defined as XLYLZL coordinates. In this coordinate system, the coordinates of a point near the measurement point on the surface of the three-dimensional model can be expressed as (x, y, f (x, y)). Where f (x,
The value of y) is calculated between each vertex and each measurement point using the ZL coordinates of the vertices P1, P2,... Pn constituting the polygon mesh where the point (x, y, f (x, y)) exists. Is obtained by complementing the reciprocal of the distance in as a weight. Specifically, the vertex Pi
Let ZL (Pi) denote the ZL coordinate of, and L (Pi) denote the distance from the vertex Pi to the measurement point.

[0084]

(Equation 2)

Note that the value of f (x, y) may be obtained by approximating a feather metric curve or curved surface by a technique such as B-spline or normal blending. Now, let the measurement point be (x
0, y0, f (x0, y0)), and if the section length obtained from the spatial frequency is d, the differential values in the XL-axis direction and the YL-axis direction can be expressed by the following equations, respectively.

[0086]

(Equation 3)

[0087]

(Equation 4)

Sections d and f specified by the spatial frequency
(X0, y0), f (x0-d / 2, y0), f (x0 + d / 2, y0)
32 is shown in FIG. FIG. 32A shows a case where the value of d is set to a narrow value d1 (high spatial frequency value).
2 (b) shows a case where the value of d is set to a wide value d2 (low spatial frequency value). Note that the method of calculating the derivative is the same in the XL-axis direction and the YL-axis direction. Therefore, only the XL-axis direction will be described here. The above formula is used to calculate the measurement point (x0, y
(X0-d / 2, y0, f (x0-d / 2, y0)), (x0-d / 2, y0), (x0-f / 2)
+ d / 2, y0, f (x0 + d / 2, y0)), so that the curve substantially sandwiched between the two points shown in the figure is smoothed as C1 or C2. This means that the feature amount has been calculated. That is, if the section d is small, the feature amount can be calculated in a more microscopic unevenness range, and if the section d is large, the feature amount can be calculated in a more macroscopic unevenness range. In this case, the calculation is performed assuming that the curve (curved surface) is smoothed. However, even if the normal differentiation processing is performed after the curve (curved surface) in the section d is actually smoothed, almost the same operation is performed. The result can be obtained. This is the same in the following calculation of the curvature.

(3-5-2b) Calculation of curvature Since the curvature depends on the normal direction of the measurement point, the calculation is performed using a local XLYLZL coordinate system determined by the normal line of the measurement point. Specifically, as shown in FIG. 33, the measurement point of the three-dimensional model is set as the origin, and Z is set in the direction opposite to the normal at the measurement point.
Use a coordinate system with an L axis. The XL axis and the YL axis are appropriately set each time. Also in this coordinate system, the coordinates of a point near the measurement point on the surface of the three-dimensional model are (x, y, f).
(X, y)), and f (x, y) can also be obtained by the above method.

The calculated average curvature κm and Gaussian curvature κg can be expressed by the following equations.

[0091]

(Equation 5)

[0092]

(Equation 6)

Now, the XL and YL coordinates of the measurement point are represented by XL
= X0, YL = y0, then ∂ ² f / ∂
^{x 2, ∂ 2 f / ∂y} 2, the value of ∂ ² f / (∂x∂y), using the section obtained from the spatial frequency length d (the reciprocal of the spatial frequency) can be approximated by the following equation.

[0094]

(Equation 7)

[0095]

(Equation 8)

[0096]

(Equation 9)

By using the above equations, the average curvature and the Gaussian curvature can be obtained from the vertex data of the three-dimensional model. In these expressions, for example, in the x-axis direction, the same sections d and f (x0, y0), f as shown in FIG.
(X0−d / 2, y0), f (x0 + d / 2, y0), and the feature amount is regarded as that the surface of the solid model sandwiched between the two points is smoothed into a curve C1 (C2). Is calculated. However, since local coordinates are used in the calculation of curvature, x0 = 0 and y0 = 0.

(3-5-3) Point Mode Processing When the point mode start button 149 of the curved surface mode processing panel 140 shown in FIG. 31 is operated, the point mode is set via the step 705 in the curved surface mode flowchart of FIG. Move on to processing. In the point mode, first, in step 706, the user waits for designation of a measurement point on the surface of the three-dimensional model in the viewer. When the measurement point is designated, the current spatial frequency, that is, the spatial frequency display section 142 of the curved surface mode processing panel 140 is determined in step 707.
Capture the value of the spatial frequency displayed in.

Next, in step 710, the characteristic amount of the curved surface is calculated. FIG. 34 is a flowchart illustrating a process of calculating the feature amount of a curved surface. The calculation of the feature amount is changed depending on the differentiation, average curvature, and Gaussian curvature selected by the feature amount selection button on the surface mode processing panel 140.
First, the processor 10 determines whether or not the selected feature amount is a curvature. If the curvature has not been selected, the differentiation has been selected.
The coordinate system of the reference plane is set as the coordinate system for obtaining the feature amount. In step 910, the differential value of the measurement point is calculated using an equation according to the direction set by the differential direction selection button 147 of the curved surface mode processing panel 140.

On the other hand, if the curvature is selected in step 901, first the normal vector at the measurement point is obtained in step 902, and the XLYL ZL coordinates shown in FIG. 33 are obtained from the normal vector obtained in step 903. Set the system. Next, it is determined whether the curvature determined in step 906 is an average curvature. If it is the average curvature here, the average curvature κm at the measurement point is obtained in step 907 by using the formulas,. On the other hand, if it is not the average curvature, the Gaussian curvature has been selected, so that step 908 is executed.
Is used to determine the Gaussian curvature κg at the measurement point.

When the characteristic amount calculation processing of the curved surface is completed as described above, in step 711, the curved surface mode processing panel 14
The calculated feature amount is displayed on the calculated value display unit 148 of 0, and the point mode processing ends. (3-5-4) Area Mode Processing In the area mode processing, when the three-dimensional model is projected on the reference plane, the feature amount of each point projected on the three-dimensional model is represented as an image. More specifically, as shown in FIG. 35 (a), on a three-dimensional model obtained by projecting a coordinate model p from the coordinate points p, p, p on the reference plane H corresponding to the position of the pixel of the canvas in the Z-axis direction. Is calculated for each point (a point on the surface on the left side of the two-dot chain line in the figure), and the density of the corresponding pixel of the canvas is determined in accordance with the calculated feature amount. This is displayed on the canvas as shown in FIG. When shifting to this mode, the user needs to adjust the posture and move the reference plane so that a desired direction of the three-dimensional model can be projected.

The curved surface mode processing panel 14 shown in FIG.
When the area mode start button 150 of “0” is operated, FIG.
Step 7 in the flowchart of the curved surface mode 8
Then, the processing shifts to the area mode processing via the line 12. In the area mode, first, in step 713, the current spatial frequency, that is, the value of the spatial frequency displayed on the spatial frequency display section 142 of the surface mode processing panel 140 is fetched. Then, in step 714, the attitude of the reference plane is captured.
When the posture of the reference plane is captured, in step 715, Z is calculated from the coordinate point corresponding to the pixel position of the canvas on the reference plane.
The coordinates of points on the three-dimensional model are calculated by projecting the three-dimensional model in the axial direction. The canvas is 48
It is assumed that pixels of 0 × 480 are arranged.

When the projection points are extracted, the feature amount calculation processing of the curved surface is performed for each of the points extracted in step 716. This processing is the same as the processing in the flowchart of FIG. 34 described in the point processing mode. When the calculation of the feature amounts for all points is completed, step 7
At 17, mapping is performed on a two-dimensional orthogonal plane, that is, a canvas plane, by changing the density of the corresponding pixel according to the feature amount of each point. Specifically, as the pixel data of each pixel on the canvas plane, a smaller brightness value is set as the absolute value of the feature value at the corresponding point is larger, and a larger brightness value is set as the absolute value of the feature value is smaller. When the value of the amount is positive, an RGB value that gives a color according to the positive or negative, such as blue when the value is negative and red when the value is negative, is set. When the mapping calculation is completed, the data mapped on the canvas is displayed in step 720, and the area mode ends.

Here, a point projected on the three-dimensional model is obtained from the coordinate point on the reference plane corresponding to the pixel position on the canvas, and the shading represented by the characteristic amount of the point is represented by the corresponding pixel. However, this involves projecting each vertex of the three-dimensional model on the reference plane, finding the corresponding point on the reference plane of each vertex, calculating the density of each vertex from the feature amount of each vertex,
Using the shades, the shades of the portion surrounded by each point can be complemented and displayed.

(3-5-5) Mapping Mode Processing In the mapping mode processing, a feature amount at each point on the surface of the three-dimensional model is calculated, and an image corresponding to the feature amount is subjected to texture mapping on the three-dimensional model surface. The image is attached to the surface of the three-dimensional model.

In the texture mapping process, as shown in FIG. 36, a texture pattern to be attached to a three-dimensional model X such as A is formed on a texture formation surface set in a texture space, and a texture formation represented by texture space coordinates is performed. Mapping data indicating the correspondence between the surface and the solid model X surface represented by the coordinates (viewer coordinates) of the solid model space to which the texture is attached is set, and based on this, coordinate conversion from the texture space to the solid model space is performed. T
The texture is formed on the surface of the three-dimensional model as shown in FIG.

Here, a polar coordinate system is used as the texture space coordinates, and a spherical surface is used as the texture forming surface. The spherical surface is used as the texture forming surface because the plane in the two-dimensional rectangular coordinate system is not appropriate here for performing texture mapping on the entire three-dimensional surface. However, if appropriate mapping is performed, the plane in the two-dimensional rectangular coordinate system can also be used as the texture forming surface,
In addition, various texture forming surfaces such as a cylindrical texture forming surface can be used.

The mapping data between the spherical surface in the polar coordinate space and the three-dimensional model is given as follows. Now, as shown in FIG. 37, for the three-dimensional model X in the viewer coordinate system,
It is assumed that a spherical surface S, which is a texture forming surface, surrounds the surface. This sphere has its origin at the center in texture space,
The radius is rb. Also, it is assumed that the origin of the viewer coordinate system and the origin of the polar coordinates coincide, and that the origin is inside the three-dimensional model. If the origin is outside the three-dimensional model, the three-dimensional model is translated so that the origin is located within the three-dimensional model.

In order to perform mapping, it is necessary to first match the coordinate systems. Therefore, first, the viewer coordinates (x, y, z) are converted into polar coordinates (r, θ, φ).
This conversion is given by the following equation.

[0110]

(Equation 10)

By this conversion, the coordinates of the vertices of the three-dimensional model data are converted to polar coordinates. From now on, the mapping data is given as follows. That is, as shown in FIG. 37, a point Pb at which a straight line passing from the origin O to a point Pa on the three-dimensional model X intersects the spherical surface S is given mapping data as a point corresponding to the point Pa on the three-dimensional model. As shown in FIG.
Pa and Pb differ only in the value of r, and the values of θ and φ match.
That is, when the vertices of the three-dimensional model data are converted into polar coordinates, the angle components θ and φ become mapping data of the corresponding points on the spherical surface as they are. Since rb is constant, there is no need to determine it after all.

The specific operation of the mapping mode processing will be described below. Panel 1 for curved surface mode processing shown in FIG.
When the mapping mode start button 151 of 40 is operated, the process proceeds to the mapping mode processing via step 721 in the flowchart of the curved surface mode of FIG.
Also in the mapping mode, first, in step 722, the current spatial frequency is fetched. Then, the feature amount calculation processing of the curved surface is performed for each of the vertices of the three-dimensional model. This processing is also performed in FIG. 34 described in the point processing mode.
This is the same process as the flowchart in FIG. When the calculation of the feature amounts is completed for all the processes, the texture mapping process is performed in step 728.

FIG. 38 is a flowchart showing the texture mapping process. In the texture mapping processing, first, as described above, the viewer coordinates of the vertices of the three-dimensional model (translated as necessary) are converted to polar coordinates. Then, 2 of θ and φ of each vertex after conversion into polar coordinates
The luminance value and RGB data of the vertex position are set at the two-dimensional coordinate position represented by the component according to the feature amount of the vertex.
The way of setting the luminance value and the RGB value is the same as in the case of the area mode processing. In step 1004, the correspondence between the viewer coordinates and the angle components of the polar coordinates is stored as mapping data. When the processing of steps 1002 to 1004 is completed for all vertices, in step 1006, image patterns on surfaces other than the vertices are obtained by complementing using the image patterns set as vertices. Specifically, for a point on a surface surrounded by vertices forming a polygon mesh, the density of each vertex is weighted according to the distance, and the average is calculated. As a result, a complete texture pattern is formed as data on the texture forming surface.

When the above processing is completed, the texture pattern obtained as data based on the mapping data is pasted on the surface of the three-dimensional model and displayed on the viewer, and the processing is terminated. Here, each vertex of the three-dimensional model is mapped to the texture forming surface, and the texture pattern of the surface surrounded by the point corresponding to each vertex is complemented from the shading obtained from the feature amount of each vertex. However, this maps the coordinates of the texture forming surface that are selected sufficiently finely and evenly and the three-dimensional model surface to obtain a corresponding point on the three-dimensional model, and calculates a feature amount at the obtained point.
A texture pattern may be formed by forming shading corresponding to the feature amount at a point on the texture forming surface corresponding to each point.

By the above-described processing, the characteristic amount of the surface of the three-dimensional model is adjusted in the curved surface mode while adjusting the spatial frequency.
It can be calculated numerically and further visually displayed as an image. Here, as shown in FIG. 29, the solid model surface surrounded by the intersection of the range on the cylinder defined by the value of d obtained by the spatial frequency and the solid model surface is regarded as a smoothed curved surface. Although the quantity has been calculated, this range may be a sphere having a radius of d instead of a cylinder. FIG. 3 is a diagram corresponding to the XLZL plane of FIG. 32 in this case.
It is shown in FIG.

In FIG. 39, the diameter is d around the measurement point.
F (xa, y) from the intersection of the sphere (circle)
0) and f (xb, y0). Then, the feature amount of the measurement point can be obtained using this.
In this way, the range of the uniform distance from the measurement point to the surface of the three-dimensional model can be used as data for calculating the feature amount regardless of the variation in the distance between the vertices.

In the area mode processing and the mapping processing, the feature amount is visually displayed by changing the density, but this is visually displayed by changing the color or the pattern of hatching or tone. You can do so. Further, as the feature value obtained from the shape, the differential value and the curvature are used here, but this may be another feature value, such as calculating the Laplacian Δ represented by the following equation. Is also good.

[0118]

[Equation 11]

Laplacian represents the strength of an edge in three dimensions. In addition, a specific coefficient of a polynomial representing a smoothed curved surface, an average of curvature, or the like may be used as the feature amount. (3-6) Restoration Mode Processing In the restoration mode processing, the missing part of the three-dimensional model is automatically restored. The basic concept of the repair mode process will be described with reference to FIG. For example, as shown in FIG.
The three-dimensional model data X is cut along a plurality of planes whose normals are in a certain axial direction. Then, a plurality of cross-sectional data (contours) can be obtained by the same calculation as in the cutting mode described above. By arranging the obtained section data in a three-dimensional space in the axial direction and generating a polygon between the sections, three-dimensional model data X ^* can be obtained. The original three-dimensional model data X and the obtained three-dimensional model data X ^* can be regarded as substantially the same if the interval between the cutting planes is sufficiently small.

Similarly, when the three-dimensional model data X having a defect as shown in FIG. 40B is cut along a plurality of planes whose normal lines are set in a certain axial direction, a plurality of cross-sectional data can be obtained. At this time, the missing portion can be determined as an unclosed cross section because the line segments are not connected in the flowchart of the line connecting process of FIG. 15B in the cutting mode. An open portion of such an unclosed cross section can be restored to a closed cross section by complementing the outline. afterwards,
Similarly, if the cross-section data is arranged in a three-dimensional space and a polygon is generated between the cross sections, a three-dimensional model X ^* is obtained. If the interval between the cutting planes is made sufficiently small, this three-dimensional model X ^* is almost the same as the original three-dimensional model X, and the defective part is restored.

It is important in this method to determine the direction of the normal to the cut surface, and it is important to set the direction in such a manner that the defective portion can be sliced appropriately. Therefore, here, the Z-axis direction of the reference plane is set as the normal direction of the cut plane, so that the user can set an appropriate direction. When the restoration mode start button 74 is operated in the flowchart of the measuring processing of FIG. 9, the processing shifts to the cutting mode processing of step 43. FIG. 41 is a flowchart showing the operation of the restoration mode process. In the restoration mode processing, first, the posture of the reference plane set by the user in step is captured. Next, the height of the three-dimensional model in the Z-axis direction is obtained,
The height between the cutting planes is obtained from this height. Here, the height is set to 1/1000 of the obtained height.

Next, in step S1105, the three-dimensional model is cut by a plane at intervals of 1 to obtain cross-sectional data. The method of obtaining the section data is the same as that described in the section mode processing. Then, it is determined whether or not the section data obtained in step 1107 has a defect, that is, whether or not the section data is an unclosed section.
To restore the section data. This repair processing will be described later in detail.

When the above processing is completed for all of the cut surfaces corresponding to the height in the Z-axis direction of the three-dimensional model, the three-dimensional model data is restored by connecting the cross-sectional data including the cross-sectional data restored in step 113. To end. (3-6-1) Cross Section Data Restoration Processing Next, the section data restoration processing in step 1109 will be described. Here, the section data is restored only from the shape near the portion where the section data is missing. That is, for example, it is assumed that the missing portion in the cross-sectional data shown in FIGS. 42A and 42B is a part of the same missing portion in the three-dimensional model. If the missing part is complemented in consideration of a part distant from the defective part, (a) and (b)
Since the shape is greatly different in a portion away from the defective portion, the restoration result is also quite different. On the other hand, when only the vicinity of the defective portion is considered, both can obtain a considerably close restoration result.

FIG. 43 is a flowchart showing the cross-section data restoration processing. Further, as an example of the cross-sectional data having a defect, it is assumed that the cross-sectional data as shown in FIG. The cross-sectional data in FIG. 44 (a) has two line segments (P
0,0, P0,1,... P0, N) and (P1,0, P1,1,
.., P1, N), and the portions between the points P0, 0 P1, 0 and between the points P0, NP1, P1 are deficient portions. First, in step 1202, a set of points whose end points are closest, that is, a set of end points that constitute a missing portion is determined. In the example of FIG.
A set of (P0,0 P1,0) and a set of (P0, N P1, N) are obtained. Here, P0,0 P1,0 is P1, P2, P0, N P
1, N is represented as P5 and P6.

Next, in step 1203, the length of the line segment is calculated, and in step 1204, the reference length for restoration is obtained based on this length. Here, the length of 1/5 of the length of the line segment from the end point is set as the reference length for restoration. And
A point located at a distance from the end point constituting the missing portion by this reference length is set as a representative point, and the representative point is obtained by appropriate interpolation processing. In FIG. 44A, for example, P0, P3, P4, and P6 are obtained as representative points.

Then, in step 1205, a curve that smoothly passes through the set of end points obtained in step 1202 and the representative point obtained from each end point obtained in step 1204 is obtained. Here, a general blending method is used as a method for obtaining a curve. Specifically, for example, FIG.
Of the end points P1 and P2 and the representative point P obtained from the end points
A smooth curve passing through 0 and P3 can be obtained as follows. That is, assuming that the points P0, P1, P2, and P3 are given as position vectors, a coordinate vector C (t) (0 ≦ t ≦ 1) on a curve passing through four points is given by the following equation by a general blending method.

[0127]

(Equation 12)

As a result, a curve that smoothly connects P1 and P2 is obtained as shown in FIG. Thereafter, in step 1206, it is determined whether or not processing of all missing parts has been completed. If processing of all missing parts has been completed, in step 1207, the curve shown in FIG. Restore some suitable points as shown in ()). Then, the section data is restored by reconstructing the profile of the section including the point cloud restored in step 1208. Thus, the cross-sectional data of FIG.
It will be repaired as shown in FIG. Thus, in the restoration mode processing, even if there is a missing portion in the three-dimensional model data, the missing portion can be repaired very easily. Here, the normal direction of the cutting plane is manually specified by the reference plane, but this may be automatically obtained by processing such as thinning of the three-dimensional model. In addition, here, each cut surface has the same normal direction, but the normal direction of each cut surface does not necessarily have to match.

As described above, in the three-dimensional shape data processing apparatus according to the present embodiment, the cutting mode processing, the distance mode,
The three-dimensional shape data can be variously processed and analyzed by the curved surface mode, the restoration mode, and the like. In the present embodiment, the measurement is optically read, but three-dimensional data created by a modeler or the like can be used. Also,
In the present embodiment, the three-dimensional model data is composed of a polygon mesh, but the three-dimensional model data may be expressed in another format. Specific examples include voxel data, a plurality of contour data, surface data in parametric expression such as NURBS, CAD data, and the like.

[0130]

According to the above description, the present invention has the following effects. That is, the three-dimensional shape data processing device according to the present invention calculates a plurality of points on the contour of the surface of the three-dimensional shape within the range defined by the distance acquired by the distance acquiring means, using the range calculating means. The amount calculation means considers the three-dimensional surface between the calculated points on the contour as a smoothed curved surface, and calculates the feature amount from the curved surface shape.

By such an operation, the feature amount is calculated by setting the range obtained by the distance obtaining means as a range in which one convex portion or concave portion exists, and even if the vertices of the three-dimensional shape data vary. The spatial frequencies in all portions of the three-dimensional shape surface become equal, and the accuracy of the feature amount can be matched in all portions. Further, if the distance obtaining means obtains the distance by calculating the distance based on the vertex data constituting the three-dimensional shape data, an appropriate distance in consideration of the balance of the entire vertex, that is, the spatial frequency It is possible to obtain

On the other hand, if the distance acquiring means acquires the distance by accepting the distance specified by the user, the characteristic amount of the curved surface excluding the high-frequency component of the three-dimensional shape surface according to the user's will. Alternatively, it is possible to arbitrarily calculate a feature amount when the curved surface is viewed macroscopically or a feature amount when the curved surface is viewed microscopically. Then, by making the feature amount a curvature, it is possible to calculate the feature amount that most represents the feature of the three-dimensional surface by appropriately adjusting the spatial frequency.

A point on the contour of the surface of the three-dimensional shape within the range of the acquired distance is centered on the measurement target point on the surface of the three-dimensional shape acquired by the range calculating means by the object point acquiring unit. Calculated by a point calculation unit, and the feature amount calculation means calculates the feature amount at the measurement target point acquired by the target point acquisition unit, the curve included in the equidistant range centered on the measurement target Since the feature amount is calculated assuming that the feature has been smoothed, the feature amount of the measurement target can be more appropriately calculated.

[Brief description of the drawings]

FIG. 1 is a functional block diagram showing an internal configuration of a three-dimensional shape data processing device according to an embodiment.

FIG. 2A is a diagram illustrating an example of a measurement target;
(B) It is a figure which shows an example of what was converted into the three-dimensional model of the measurement object of (a), (c) is the elements on larger scale of (b).

FIG. 3 is a diagram showing a data structure of a three-dimensional model.

FIG. 4 is a diagram showing an example of a display screen of a display in the three-dimensional shape data processing device according to the embodiment.

5A is an explanatory diagram illustrating a canvas coordinate system, and FIG. 5B is an explanatory diagram illustrating a viewer coordinate system.

6A is a diagram illustrating a reference plane, and FIG. 6B is a diagram illustrating a data structure of the reference plane.

FIG. 7A is a diagram showing a change in posture on a reference plane;
(B) is a diagram showing the movement of the reference plane.

FIG. 8 is a main flowchart of the three-dimensional shape data processing device according to the embodiment;

FIG. 9 is a flowchart illustrating a measuring process.

FIG. 10 is a diagram illustrating a measuring processing operation panel.

FIG. 11 is a flowchart showing reference object display processing.

FIG. 12 is a flowchart illustrating reference object movement / rotation processing.

FIG. 13 is a diagram illustrating a rotation / movement amount input panel.

FIG. 14 is a flowchart showing a cutting mode process.

FIG. 15A is a flowchart illustrating a cross-sectional data calculation process, and FIG. 15B is a flowchart illustrating a line segment joining process.

FIG. 16 is a flowchart illustrating a connection process between intersections.

FIG. 17 is a flowchart illustrating a process of connecting a line segment sequence;

18A is a diagram illustrating an example of a state where a reference plane cuts a polygon mesh, and FIG. 18B is a diagram illustrating an example of an intersection between the reference plane and the polygon mesh.

19A is a diagram illustrating an example of an intersection formed by one polygon mesh, FIG. 19B is a diagram illustrating a state in which the intersections illustrated in FIG. It is a figure which shows the state which connected the line segment shown by (b).

20A is a diagram for explaining a method of calculating the contour length of the cut surface, and FIG. 20B is a diagram for explaining a method of calculating the area of the cut surface.

FIG. 21 is a flowchart showing a distance mode process.

FIG. 22 is a diagram showing a selection panel.

23A is a diagram illustrating a state in which a cross section is displayed on the canvas, FIG. 23B is a diagram illustrating a state in which a start point and an end point are selected from the contour of the cross section in FIG. () Is a diagram showing a state in which a passing point for the start point and the end point in (b) is selected.

24A is a diagram illustrating a state in which a stereo model is displayed in a viewer, and FIG. 24B is a diagram illustrating a state in which a start point, an end point, and a passing point are designated from the stereo model displayed in FIG. FIG. 3C is a diagram showing a state where a reference plane passing through the designated three points is displayed, and FIG. 4D is a diagram showing an image of a canvas defined by the reference plane of FIG. .

FIG. 25 is a flowchart illustrating a path length measurement process.

26A is a diagram illustrating a state in which four points are designated from the three-dimensional model on the viewer, and FIG. 26B is a diagram illustrating a path obtained from three of the four points designated in FIG. And
(C) is a diagram showing a path obtained from three points different from (b) out of the four points specified in (a).

27A is a diagram illustrating one pop-up menu in an N-point mode, and FIG. 27B is a diagram illustrating another pop-up menu in an N-point mode.

FIG. 28 is a flowchart showing a curved surface mode process.

29A is a diagram illustrating a curved surface included in a range defined by a spatial frequency, and FIG. 29B is a diagram illustrating a state where the curved surface illustrated in FIG.

FIG. 30 is a flowchart showing a reference value calculation process of a spatial frequency.

FIG. 31 is a diagram showing a curved surface mode processing panel.

FIG. 32 (a) is a diagram showing variables used for calculating feature values when a high spatial frequency is set, and FIG. 32 (b) shows variables used for coefficients of the feature values when a low spatial frequency is set. FIG.

FIG. 33 is a diagram showing a coordinate system defined by a normal line of curvature.

FIG. 34 is a flowchart showing a process of calculating a feature value of a curved surface.

FIG. 35 (a) is a diagram showing projection of pixels from a reference plane onto a three-dimensional model, and FIG. 35 (b) is a diagram showing an area of the three-dimensional model projected from the reference plane on a canvas.

FIG. 36 is a diagram illustrating a texture mapping process.

FIG. 37 is a diagram for describing mapping between the surface of a three-dimensional model on a rectangular coordinate system and a spherical surface of a polar coordinate system.

FIG. 38 is a flowchart showing a texture mapping process.

FIG. 39 is a diagram illustrating variables for calculating a feature amount when a range of an area obtained from a spatial frequency is within a spherical surface.

40A is a schematic diagram showing a procedure for decomposing a solid model having no defect into cross-sectional data and then reproducing the solid model again, and FIG. 40B is a diagram showing a three-dimensional model having a defect decomposed and restored to cross-sectional data. It is a figure showing the procedure which reproduces a three-dimensional model later.

FIG. 41 is a flowchart showing a restoration mode process.

42A is a diagram illustrating an example of cross-sectional data having a defect, and FIG. 42B is a diagram illustrating an example of cross-sectional data having the same defect as in FIG. is there.

FIG. 43 is a flowchart showing a cross-section data restoration process.

44A is a diagram showing an example of cross-sectional data having a defect, FIG. 44B is a diagram showing a state in which a defective portion is complemented by a curve, and FIG. 44C is a diagram showing the cross-sectional data of FIG. FIG. 11 is a diagram showing a state in which is restored.

FIG. 45 is a diagram showing a variation in distance between measurement points when a measurement target is measured with a range finder.

46A is a diagram showing a three-dimensional shape surface represented by three-dimensional shape data on which high frequency components are superimposed, and FIG. 46B is a diagram showing a state in which high frequency components are removed from the diagram shown in FIG. is there

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical measurement part 2 Measurement object modeling part 3 Disk device 4 Display 5 Mouse 6 Keyboard 7 GUI system 8 Main module 9 Measuring module 10 Processor

Claims (10)

[Claims] 1. A three-dimensional shape data processing device for calculating a feature quantity representing a shape of a three-dimensional shape surface represented by three-dimensional shape data, comprising: distance obtaining means for obtaining a magnitude of a distance; Range calculating means for calculating a plurality of points on the contour of the three-dimensional surface existing within a range defined by the distance, and a curved surface obtained by smoothing the three-dimensional surface between the calculated points on the contour. A three-dimensional shape data processing apparatus having a feature amount calculating means for calculating a feature amount from the curved surface shape. 2. The three-dimensional data processing apparatus according to claim 1, wherein the distance obtaining means obtains the distance by calculating the distance based on vertex data constituting the three-dimensional shape data. 3. The three-dimensional data processing device according to claim 1, wherein the distance obtaining unit obtains the distance by receiving a distance specified by a user. 4. The three-dimensional data processing apparatus according to claim 1, wherein said characteristic amount is a curvature. 5. The range calculating means, comprising: a target point obtaining unit that obtains a measurement target point on the three-dimensional shape surface; and the three-dimensional object within a range of the obtained distance around the measurement target point. 5. The method according to claim 1, further comprising: a contour point calculation unit configured to calculate a point on a contour of the shape surface, wherein the feature amount calculation unit calculates a feature amount at the measurement target point acquired by the target point acquisition unit. Item 3. The three-dimensional data processing device according to item 1. 6. A computer which calculates a feature quantity representing a shape of a three-dimensional surface represented by three-dimensional shape data.
A computer-readable recording medium on which a program to be operated as a dimensional data processing apparatus is recorded, wherein the computer is located within a range defined by a distance acquisition unit that acquires a magnitude of a distance, and the acquired distance. 3 above
A range calculating means for calculating a plurality of points on the contour of the three-dimensional surface; and a feature amount is calculated from the curved surface shape by regarding the three-dimensional surface between the calculated points on the contour as a smoothed curved surface. A recording medium that stores a program that functions as a feature amount calculating unit. 7. The recording medium according to claim 6, wherein the distance obtaining means obtains the distance by calculating the distance based on vertex data constituting three-dimensional shape data. 8. The recording medium according to claim 6, wherein said distance obtaining means obtains said distance by receiving a distance specified by a user. 9. The recording medium according to claim 6, wherein the characteristic amount is a curvature. 10. The range calculation means, a target point acquisition unit for acquiring a measurement target point on the surface of the three-dimensional shape, and the three-dimensional shape existing within the range of the acquired distance around the measurement target. 10. A contour point calculation unit that calculates a point on a contour of the surface, wherein the feature amount calculation unit calculates a feature amount at the measurement target point acquired by the target point acquisition unit. 11. A recording medium according to claim 1.