JPH01306971A - Shape model designing device - Google Patents

Abstract

PURPOSE:To design a columnar or cylindrical three-dimensional solid body in a short time with the columnar body having a polygonal cross section by providing a calculating means which produces two-dimensional segment data of a regular polygon from designated values of the number of angles and radius of the osculating circle. CONSTITUTION:A segment producing section (two-dimensional segment producing and changing section) 5 which calculates the vertex coordinates of a regular polygon from designated values of the number of angles and radius of the osculating circle and produces the segment data of the polygon formed by connecting each vertex with straight lines in a two-dimensional plane is provided. More over, a transforming section 7 which moves and rotates the segment data of the polygon by designated quantities in a three-dimensional space and transforms two-dimensional graphics into a three-dimensional graphic is provided, in order to produce a solid body having polygonal cross sections at plural required points. Therefore, segment data which give outer shapes of cross sections are automatically produced when the number of angles and the radius of the osculating circuit are designated and a solid body, such as a columnar body, cylindrical body, etc., having a point-symmetrical cross section can be designed in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a shape model design device such as a three-dimensional CAD device.

[Summary of the invention]

A calculation means is provided to generate two-dimensional line segment data of a regular polygon with a specified number of angles and tangent radius, so that a columnar or cylindrical three-dimensional solid whose cross section is a polygon can be designed in an extremely short time. It is a shape model design device that has been developed.

[Conventional technology]

In the design method called CAD, which handles three-dimensional data on a computer and designs a shape model with a free-form surface, several cross-sectional shapes are designed on a two-dimensional plane, and then calculated by rotation and translation operations. A design procedure may be used in which cross-sectional contour curves are arranged in a three-dimensional space, and a curved surface is calculated and generated by interpolating between the respective curves, which is used as the model's contour data.

Such a design method is applied to the design of columnar or cylindrical articles, such as grips of tools, knobs of electronic devices, solid or liquid containers, and the like. Possible cross-sectional shapes include polygons such as quadrangles, pentagons, and hexagons.

Conventionally, in order to design such a cross-sectional shape on a two-dimensional plane, in the case of a regular polygon, the coordinates of the vertices of the polygon are calculated by dividing the angle in the same direction as the circle centered on the origin of the X-Y coordinates. It was obtained by connecting each vertex with a straight line.

After designing the basic shape of the cross section, a quadratic or cubic Bezier curve, etc. is generated to round the corners, and the control points of the curve are moved and modified to obtain the desired free-form cross-sectional shape. Perform the transformation operation as shown below.

Once the cross-sectional design of the required location is completed, the data of each cross-sectional curve is translated and rotated to arrange the cross-section in three-dimensional space, and furthermore, a batch ( (area) to obtain the outline of the model.

[Problem to be solved by the invention]

As described above, designing a model of a columnar or cylindrical body with a three-dimensional free-form surface based on regular polygons is very time-consuming.

The present invention aims to solve this problem and enable the design of a shape model in a short time.

[Means for Solving the Problems] The shape model design device of the present invention calculates the coordinates of the vertices of a regular polygon based on the designated values of the number of angles and the tangent radius, and calculates the line segments of the polygon connecting each of the vertices. A line segment generation unit (5) generates data on a two-dimensional plane, and a three-dimensional It includes a quadratic to cubic converter (7) that performs a specified amount of movement and rotation in space.

[Effect]

By specifying the number of angles and the tangent radius, line segment data giving the cross-sectional outline is automatically generated. Therefore, it is possible to design three-dimensional bodies such as columnar bodies and cylindrical bodies whose cross sections are point-symmetric in a short time.

〔Example〕

FIG. 1 shows a functional block diagram of the shape model designing device of the present invention. This shape model design device has a computer configuration and includes a calculation section 1 and a display section 2 (or display terminal). A typical design procedure is to form a plurality of cross-sectional curves SC on the X-Y plane, as shown in the display screen 3a of FIG. Perform operations such as three-dimensional rotation and movement to create X-Y-
A shape model U represented by a three-dimensional free-form surface is obtained by arranging each cross-sectional curve in the Z space and then performing interpolation calculations between the cross-sectional curves to form batches (surface elements).

FIG. 2 shows a flowchart of the cross-sectional design procedure.

A keyboard, light pen, mouse, etc. are used to input design data and instructions.When the display menu on the screen is turned pink, the computer displays operational guidance to inform you of the data to be input, so you can input according to the instructions. I do.

For example, in the menu display, "2D curve generation"
When you select the menu, a menu screen with shape types such as circles, ellipses, polygons, and free curves appears. When you select a polygon, you will be asked for the angle IN and radius r, so go to step S.
1. In S2, enter the data manually using the numeric keypad. In the case of a pentagon, the vertices P and -P5 of the pentagon are then found on the circumference of the circle C with radius r in a loop of steps 83 to S6.・In other words, the entire circumference is 1/N, 2/N---
−−−−−=−n/Point P on the circumference divided by N
, is calculated.

Next, in step S7, a Bezier curve connecting the vertices P and ~P5 with a straight line is generated, and in step S8, a regular pentagonal cross-sectional line is displayed on the X-Y plane as shown in screen 3a of FIG. . By repeating this process, it is possible to easily manually input cross-sectional line data for each key point of the design target shape model.

In FIG. 1, the above-mentioned input operation is detected by the human operator unit 4 of the calculation unit 1, and further processed by the two-dimensional segment generation/modification unit 5 to generate segment data constituting the cross-sectional line. Ru.

The generated data is stored in the two-dimensional segment haphazard memory 6.
is memorized. The contents of the frame buffer memory 6 are periodically read out, converted into pixel data for display, and placed in the frame buffer memory 10. The display 3a in FIG. 1 is performed based on the contents of the frame buffer memory 10.

The data DXy in the segment buffer memory 6 is
As shown in the data structure in the figure, it is managed by a management table 11, and for each cross-sectional line, the starting address of segment data AI, A2 -----1 and the number of segment data k, Xk 2 ------- -- is recorded in table 11. Corresponding address A of buffer memory 6,
Segment data DXy is stored in each block of +k+, A2+k2--'-"-.

Generation of a three-dimensional curved surface based on the cross-sectional line is performed as in flowchart 1 in FIG. First, in step S1, "3D curve operation" is selected from the menu screen, and in step S2, one of the cross-sectional lines on the screen 3a is indicated with a cursor, etc., and in step S3, "3D movement" is selected. A menu for 3D operations such as ``3D rotation'' is displayed on the screen.

If, for example, "three-dimensional movement" is selected in step S4, a message asking for the amount of movement for each of the X, Y, and Z axes will appear on the screen, and the amount of movement data will be input in step S5. Furthermore, “3D rotation”
If the operation ' is required, steps S4 and S5 are repeated to input the rotation amounts of each of the x, y, and z axes.

After entering the necessary data, proceed to the next step S6.
A rotation operation is performed. This calculation is performed by the calculation unit 1 in Figure 1.
This is performed in the converting section 7. The three-dimensional segment data D My2 resulting from the calculation is sent from the conversion unit 7 to the three-dimensional segment buffer memory 9 and stored therein in step S7. As shown in the data structure of FIG. 3, the two-dimensional and three-dimensional segment panzer memories 6.9 actually use the same memory, and are stored for each section line in a block area managed by table 11. Ru. At this time again.

In step S8, as shown in FIG. 3, the amount of parallel movement and rotational movement of each of the X, Y, and Z axes are recorded in the management table 11.

Furthermore, in the next step S9, the screen is switched to the three-dimensional screen display 3b, and the cross-sectional line converted in step SIO is displayed in a three-dimensional space, for example, in a different color from the others. 3D display is 3
This is done by transferring the data in the dimensional segment buffer memory 9 to the frame buffer memory 0 via a perspective display transformation 7 trix (not shown).

In the flowchart of FIG. 4, in order to arrange another cross-sectional line in the three-dimensional space, "2-dimensional to three-dimensional conversion" is selected from the menu display in step S11. As a result, the display switches to the two-dimensional display screen 3a that is the object of operation (step 512). That is, frame buffer memory 0 is rewritten to the contents of two-dimensional segment buffer memory 6. When the next cross-sectional line to be converted is picked on the screen 3a (step 513), the process jumps to step S4, and from then on, conversion such as movement, rotation, etc. and display are performed according to steps 84 to SIO as described above. .

Through the above two-dimensional to three-dimensional conversion operation, segment data in which cross-sectional lines are arranged in three-dimensional space is obtained.

If you need rounding deformation to round the corners of a polygonal section,
Furthermore, perform the following operations.

As shown in FIG. 5, first, by specifying the deformation control point PDM on the cross section &mD of the polygon, the curve segment K is
s. Define the area in which to generate. Furthermore, these deformation control points P. M is the end point P. If two control points P, ,P2 are specified internally as ,P3, then there are four control points P. ~P3
The cubic Bezier vector function R(t)=(1-t)'PO+3(1'-t)2Pl determined by the two-dimensional coordinates of
+3(1-t)t2P2+t3P3 segment of the rounding deformation curve) Ksc can be generated (
t is a parameter from 0 to 1).

If this operation is performed for each corner of the polygon, a cross-sectional curve Sc shown in screen 3a of FIG. 1 is obtained.

This rounding transformation is performed in the two-dimensional segment generation/modification unit 5 shown in FIG. 1, and the data of the transformed segment is transferred to the buffer memory 6 and rewritten.

Next, when "2D-3D conversion" is selected from the menu, the conversion unit 7 reads the values of the translation amount and rotation amount in the management table 11 in FIG. 3 for the transformed segment, and converts the transformed segment into 3D data. administer. The recalculated three-dimensional space segment data is transferred from the conversion unit 7 to the three-dimensional segment buffer 9, and the block area storing the corresponding segment data is rewritten. The correction results are displayed on the three-dimensional screen 3b. Therefore, the correction results in two dimensions can be confirmed in three dimensions. To further modify the segment of the deformation curve, return to 2D and select the control point P. -P3
and perform the quadratic-cubic transformation again.

Contrary to the above, it is also possible to perform partial correction on a curve in a three-dimensional space, convert the correction result into two-dimensional data, display it, and confirm the deformation in the two-dimensional curve. In this case, the three-dimensional segment generation/alteration unit 8 shown in FIG. 1 makes necessary corrections to the segment data. Next, when 3D-2D conversion is performed, the 3D segment with the corrected conversion part M is inversely converted into a 2D segment based on table 11 in FIG. Then, the display is switched to the two-dimensional screen 3a, and the correction results are displayed as a two-dimensional curve.

When the three-dimensional spatial arrangement of the cross-sectional curves is completed as described above, a process of placing batches between the curves is then performed.

This process is performed using a cross-sectional curve S, as shown in the display screen 3b of FIG. A three-dimensional curve SP such as a B-spline curve connecting control points on the circumference of is obtained, and a quadruple punch is calculated and generated using four adjacent points of the many control points on this curve as nodes. It is obtained by The shape model U is represented by a set of these punches.

The designed geometric model is then transferred to a tool bus generation routine to generate a program for the NC milling machine.

〔Effect of the invention〕

As described above, the present invention automatically generates line segment data of regular polygons by simply specifying the number of angles and the tangent radius. 3D model design can be done in an extremely short time.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram of the shape model design device according to the present invention, FIG. 2 is a flowchart showing the procedure for generating a polygonal cross section, and FIG. 3 is a two-dimensional and three-dimensional data configuration diagram of the constituent elements of the cross-sectional line. FIG. 4 is a flowchart showing the procedure for generating a cubic curve from a quadratic curve, and FIG. 5 is a diagram of curve segments showing rounding deformation processing. In addition, in the symbols used in the drawings, 1----------1 calculation section 2--・---1--Display section 3a, 3b, -
Display screen 4--------------Operation input section 5-----
-----Two-dimensional segment generation/change unit 6------
Two-dimensional segment buffer memory 7
Conversion unit 8--1--3-dimensional segment I/generation/
Changing unit 9-11--------- Three-dimensional segment buffer memory 10----11111 Frame haphazard memory 11------- ---Table S c """""-'----Cross-sectional curve U ---
----It is a shape model.

Claims (1)

[Claims] A line segment generation unit that calculates the vertex coordinates of a regular polygon using each specified value of the number of angles and tangent radius, and generates line segment data of a polygon connecting each vertex on a two-dimensional plane, and multiple polygons. In order to generate a solid body with key cross-sectional outline lines as A shape model design device comprising: