JP2740484B2 - Graphic processing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a graphic processing system, and more particularly, to a graphic conversion system between a two-dimensional plane figure and a three-dimensional roll figure.

[0002]

2. Description of the Related Art Conventionally, this type of graphic processing system converts a two-dimensional shape data into a three-dimensional surface data by converting the two-dimensional shape data into a three-dimensional surface data and displaying the roll surface by connecting a plurality of three-dimensional planes. There is a three-dimensional plane approximation method which approximates and displays the data, which can reduce the amount of calculation as compared with the curved surface data conversion method, but is inferior in the naturalness of the roll figure.

FIG. 7 is a conceptual diagram of the above-mentioned prior art.
(A) is a plan view, (b) is a roll shape displayed by a curved surface data conversion method, and (c) is a roll shape displayed by a three-dimensional plane approximation method.

In the curved surface data conversion method, the position of two-dimensional data on a roll surface is determined by solving a differential equation, and three-dimensional curve data is created and displayed. In the three-dimensional plane approximation method, as shown in FIG. 8, a connection destination (ridge line) of a plane to be connected is approximately expressed as a group of contact planes on a roll curved surface.

[0005]

In the conventional method described above, the curved surface data conversion method is used for converting a two-dimensional plane into three-dimensional curved surface data, or conversely, for converting a three-dimensional data back to a planar shape. Since the transformation is performed by solving the differential equation, there is a disadvantage that the calculation amount is large and a high-performance computer is required.On the other hand, in the three-dimensional plane approximation method, the three-dimensional approximate roll shape has ridge lines on the roll surface. When the length of the approximated contact plane group in the roll direction is smaller than the actual roll shape length because it is created by connecting the contacting planes, and when returning from the created 3D plane to the 2D plane, However, there is a disadvantage that the length needs to be corrected.

[0006]

A first invention converts a two-dimensional plane figure into a three-dimensional roll surface and displays the converted three-dimensional roll surface on a display device via a three-dimensional figure processing device. In the graphic processing method in the case where the two-dimensional plane figure is developed, the developed figure shape data storage means for storing the developed figure shape data of the two-dimensional plane figure; Roll surface dividing means for dividing the two-dimensional planar figure into a three-dimensional roll curved surface by a second algorithm by a second algorithm. And a development control device for displaying the three-dimensional roll curved surface on a display device via the three-dimensional graphic processing device.

[0007] The second invention is based on the first invention.
The first algorithm is based on the development view creation information prepared in advance corresponding to the development view shape data, and calculates the number of divisions in the direction perpendicular to the roll direction and the division at that time using a division number calculation formula prepared in advance. A method of calculating a length, wherein the second algorithm is a method of approximating the roll surface defined by the developed view shape data using the number of divisions and the division length.

[0008]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention, FIG. 2 is a flowchart showing the operation of the roll shape approximating apparatus 1 in FIG. 1, and FIG. 3 is a roll curved surface developed on a plane and a cross section of the roll shape. FIG. 4, FIG. 4 is an image diagram in which the developed plane shown in FIG. 3 is divided into a plurality of surfaces, FIG. 5 is a cross-sectional view when the divided plane shown in FIG. 4 is approximated to a roll shape, and FIG. It is a figure showing an example of a display of a result.

As shown in FIG. 1, the graphic processing method of the present embodiment comprises a roll shape designating device 1, a three-dimensional graphic processing device 2, a display device 21, a developed view data creating device 3, a developed view shape data 31, It is composed of diagram creation information 4 and a development diagram control device 5.

The roll shape approximating apparatus 1 includes a roll curved surface dividing means 11 and a divided surface connection processing means 12.

Next, the operation of the graphic processing system of this embodiment will be described with reference to FIGS.

When the roll shape approximating device 1 is started from the developed view data creating device 3, the roll curved surface dividing means 11 is started. When the roll surface dividing means 11 is activated, in the roll surface information acquisition processing 201 in FIG. 6, the development as shown in FIG. 3 stored in the development view shape data 31 created by the development view data creation device 3 The element data D1 to D4 representing the figure plane shape, the roll center angle Θ1 representing the sectional shape, and the roll radius R are read.
The division length L1 and division reference angle A stored in the development view creation information 4 are read, and the division number N and division length L shown in FIG.
2 is calculated based on the following equation. Note that the division reference angle A is an angle serving as a reference at the time of division predetermined by the system, and is a value determined from an empirical rule or the like.

The number of divisions N = ((Θ1 * R-2 * L1) /
(R * A * 2)) + 2 division length = (Θ1 * R−2 * L1) / (N−2) When N and L2 are calculated, division plane creation processing 203
From the division length L1 read in the pre-processing and the division length L2 calculated, a line segment from H1 to H (N-1) with respect to the element D1 so as to be perpendicular to the roll direction as shown in FIG.
The developed plane is divided into F1 to FN, and divided plane data is created. When the above processing is completed, the roll curved surface dividing means 11 transfers control to the divided surface connection processing means 12.

As shown in FIG. 5, F1 and F1 in FIG.
F1 so that both ends of N are in contact with both ends of the roll curved surface.
And the other ends of FN are connected by N surfaces F2 to create an approximate cross section of a roll curved surface.

When the processing is completed, the split plane connection processing means 12 transfers control to the developed view control device 5. Development view control device 5
Is obtained by using the divided data of FIG. 4 and the cross-sectional data of FIG.
Is displayed on the display device 21 as shown in FIG.

As described above, the present invention divides the two-dimensional development plane shown in FIG. 3 as shown in FIG.
Since the roll surface is approximated with the size as it is, when the three-dimensional shape created as shown in FIG. 6 is returned to the original two-dimensional plane, there is an effect that the length correction becomes unnecessary.

[0018]

As described above, the present invention divides a two-dimensional plane into a plurality of planes and approximates the three-dimensional roll shape from the divided planes. Also, when returning to the two-dimensional plane from the above, there is an effect that the correction of the length in the roll direction becomes unnecessary.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of the present invention.

FIG. 2 is a flowchart showing an operation of the roll shape approximating apparatus 1 in FIG.

FIG. 3 is a diagram illustrating a roll curved surface developed on a plane and a cross section of a roll shape according to the present embodiment.

FIG. 4 is an image diagram in which the development plane shown in FIG. 3 is divided into a plurality of planes.

5 is a cross-sectional view when the divided plane shown in FIG. 4 is approximated to a roll shape.

FIG. 6 is a diagram showing a display example of a result processed according to the present invention.

FIG. 7 is a conceptual diagram of a conventional technique.

FIG. 8 is an explanatory diagram of a conventional technique.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Roll shape approximation apparatus 2 3D graphic processing apparatus 3 Development view data creation apparatus 4 Development view creation information 5 Development view control apparatus 11 Roll surface division means 12 Division plane connection processing means 21 Display device 31 Development view shape data

Claims (2)

(57) [Claims] 1. A graphic processing method for converting a two-dimensional planar graphic into a three-dimensional roll surface and displaying the converted three-dimensional roll surface on a display device via a three-dimensional graphic processing device. A developed shape data storage unit for storing developed shape data of the two-dimensional planar figure; and dividing the two-dimensional planar figure defined by the developed shape data into a direction perpendicular to the roll direction by a first algorithm. Roll surface dividing means; dividing surface connection processing means for approximating the divided two-dimensional plane figure to the three-dimensional roll surface by a second algorithm; and converting the approximated three-dimensional roll surface to the three-dimensional roll surface. A graphic processing system, comprising: a developed view control device for displaying on a display device via the graphic processing device. 2. The method according to claim 1, wherein the first algorithm divides the image in a direction perpendicular to the roll direction using a division number calculation formula prepared in advance, based on development drawing creation information prepared in advance corresponding to the development drawing shape data. A method of calculating the number and the division length at that time, wherein the second algorithm is a method of approximating the roll surface defined by the developed view shape data using the division number and the division length. 2. The graphic processing method according to claim 1, wherein: