Industrial mold curved surface filling method and device

Abstract

The application belongs to the technical field of computer aided design, and provides an industrial mold curved surface filling method and device, and the technical scheme is as follows: in response to a type selection instruction, corresponding ring line column information is automatically searched according to the selected type; whether the ring line column has an error is judged, if yes, the ring line column is automatically repaired, if the repair is successful, the ring line column is automatically divided into a four-side contour according to the related information of the repaired ring line column, if there is no error, the ring line column is directly divided into a four-side contour according to the related information of the ring line column; the divided four-side contour is drawn into a NURBS curved surface; whether there is a neighboring surface of the ring line column is judged, if yes, the information of the neighboring surface and the line is acquired, the control points and the weight of the NURBS curved surface are automatically adjusted, so that the curved surface and the neighboring surface maintain a certain continuity. The filling curved surface is fast and high in quality.

Description

Technical Field

[0001] This invention belongs to the field of computer-aided design technology, and in particular relates to a method and apparatus for filling curved surfaces of industrial molds. Background Technology

[0002] The statements in this section are merely background information related to the present invention and do not necessarily constitute prior art.

[0003] While surface filling technology is widely used in the design of curved surfaces for industrial molds, existing technologies still have some shortcomings:

[0004] 1. Quality: Due to the irregular curvature changes and complex geometry of the boundary lines of complex curved surfaces in industrial molds, the surface filling algorithm may not be able to match every detail perfectly, resulting in tiny gaps or discontinuities at the boundaries, which affects the overall accuracy and appearance quality of the surface.

[0005] 2. Efficiency: The contour boundaries of complex surfaces in industrial molds are often highly complex, containing numerous details and irregular shapes. For such complex boundaries, surface filling algorithms require extensive computation and iteration to generate suitable surfaces, leading to excessively long computation times, especially when dealing with large-scale industrial mold surface models, which may affect design and development efficiency.

[0006] 3. In terms of flexibility: The parameter settings for industrial mold surface filling are relatively complex. For example, how to ensure the continuity between the filled surface and adjacent curves depends on the designer's experience and knowledge. If the continuity is low, it will lead to visual discontinuity and damage the surface quality of the vehicle. Summary of the Invention

[0007] To address at least one of the technical problems mentioned above, this invention provides a method and system for filling curved surfaces in industrial molds. This system can perform a series of fully automated processes, including automatic retrieval of continuous lines, line array repair, ring line array judgment, ring line array segmentation, surface filling, and surface adjustment. This reduces reliance on the professional knowledge and experience of designers and enables rapid, high-quality surface filling.

[0008] To achieve the above objectives, the present invention adopts the following technical solution:

[0009] The first aspect of the present invention provides a method for filling curved surfaces of industrial molds, comprising the following steps:

[0010] In response to the type selection command, the corresponding ring line column information is automatically retrieved based on the selected type;

[0011] Determine if there are errors in the loop column. If so, automatically repair it into a loop column. If the repair is successful, automatically segment it into a polygonal outline based on the relevant information of the successfully repaired loop column. If there are no errors, directly segment it into a polygonal outline based on the relevant information of the loop column.

[0012] The segmented polygonal contours are drawn as NURBS surfaces;

[0013] Determine if there are adjacent faces in the loop line column. If so, obtain information about the adjacent faces and lines, and automatically adjust the control points and weights of the NURBS surface to maintain a certain continuity between the surface and adjacent faces.

[0014] Furthermore, the step of automatically retrieving the corresponding ring line column information based on the selected type in response to the type selection instruction includes:

[0015] If the response type is a sheet, the topology information of all sheets is automatically retrieved, and the inner ring boundary line information is obtained based on the topology information of all sheets.

[0016] If the response type is a boundary line or a line, automatically retrieve the connected loop columns.

[0017] Furthermore, the criterion for determining whether there is an error in the loop line column is as follows: if the line column is separated, intersecting, overlapping, or the number of lines in a group of the loop line column exceeds the set number, then the loop line column is determined to have an error.

[0018] Furthermore, if errors exist in the circular column, the process of automatically repairing it into a circular column includes:

[0019] If the line sequence is separated, determine whether the distance between two near endpoints of the line sequence is less than the set distance tolerance. If it is satisfied, the line sequence is determined to be a continuous line; otherwise, the line sequence is determined to be a non-continuous line.

[0020] If two lines intersect, the intersection point is taken as the new endpoint;

[0021] If there are overlapping lines, discard the redundant line sets;

[0022] If the number of lines in a group of loop lines exceeds the set number, the line group is converted into a single line based on the relevant information of the line group within the loop. The single-lined line group and the remaining line groups are then combined to form a loop. If the number of lines in a group still exceeds the set number after single-line conversion, the lines are grouped, auxiliary lines are added, and then a loop is formed again.

[0023] Furthermore, based on the relevant information of the inner loop line column, it is automatically segmented into a polygonal contour, including:

[0024] If the number of lines in a loop exceeds the set number, calculate the curvature and tangent direction of each curve at the endpoint. If the curvature error between two adjacent curves at the endpoint is within the preset range and the tangent angle is less than the set angle, collect continuous data points of adjacent curves for fitting to generate a simplified curve. Then, combine the simplified line group with the remaining line groups to form a loop.

[0025] If, after processing, the number of lines in a group still exceeds the set number, the lines will be grouped, auxiliary lines will be added, and then loops will be formed.

[0026] Furthermore, the least squares method or iterative optimization method can be used when automatically adjusting the control points and weights of the NURBS surface.

[0027] A second aspect of the present invention provides an industrial mold curved surface filling device, comprising:

[0028] An automatic retrieval module is used to automatically retrieve the corresponding ring column information based on the selected type in response to a type selection command;

[0029] The loop column repair module is used to determine whether there are errors in the loop column. If so, it is automatically repaired into a loop column. If the repair is successful, it is automatically segmented into a polygonal contour based on the relevant information of the successfully repaired loop column. If there are no errors, it is directly segmented into a polygonal contour based on the relevant information of the loop column.

[0030] The surface drawing module is used to draw the segmented polygonal contours into NURBS surfaces;

[0031] The surface adjustment module is used to determine whether there are adjacent surfaces in the loop line column. If so, it obtains information about the adjacent surfaces and lines, and automatically adjusts the control points and weights of the NURBS surface to maintain a certain continuity between the surface and the adjacent surfaces.

[0032] A third aspect of the present invention provides a computer-readable storage medium.

[0033] A computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-described method for filling curved surfaces of an industrial mold.

[0034] A fourth aspect of the present invention provides a computer device.

[0035] A computer device includes a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the above-described method for filling curved surfaces of an industrial mold.

[0036] A fourth aspect of the present invention provides a program product, which is a computer program product including a computer program that, when executed by a processor, implements the steps in the above-described method for filling curved surfaces of an industrial mold.

[0037] Compared with the prior art, the beneficial effects of the present invention are:

[0038] 1. This invention automatically repairs erroneous loop columns. After repair, the relevant information of the loop columns is automatically divided into four-sided contours and drawn into NURBS surfaces. Combining the information of adjacent surfaces and lines, the control points and weights of the NURBS surfaces are automatically adjusted to maintain a certain continuity between the surfaces and adjacent surfaces. This solves the problem of discontinuity in the boundary lines of complex surfaces in industrial molds and improves the overall accuracy and appearance quality of the surfaces.

[0039] 2. This invention improves the efficiency of industrial mold surface design by automatically retrieving continuous lines, repairing line arrays, judging loop lines, dividing loop lines, filling surfaces, and adjusting surfaces in a fully automated process when processing large-scale industrial mold surface models.

[0040] Advantages of additional aspects of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0041] The accompanying drawings, which form part of this invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention.

[0042] Figure 1 This is a flowchart of an industrial mold surface filling method provided by an embodiment of the present invention;

[0043] Figure 2 This is a schematic diagram of the inner ring boundary of the sheet body provided in an embodiment of the present invention;

[0044] Figure 3 This is a reference diagram for determining the separation of ring lines provided in an embodiment of the present invention;

[0045] Figure 4 This is a reference diagram for determining the intersection of ring lines provided in an embodiment of the present invention;

[0046] Figure 5 This is a reference diagram for determining the overlap of ring lines provided in an embodiment of the present invention;

[0047] Figure 6 This is a reference diagram for determining the linearization of an array, provided in an embodiment of the present invention.

[0048] Figure 7This is an image showing the automatic judgment result of adding auxiliary lines provided in an embodiment of the present invention;

[0049] Figure 8 These are schematic diagrams of curves 2, 3, and 4 provided in the embodiments of the present invention;

[0050] Figure 9 This is a schematic diagram of multi-line auxiliary segmentation provided in an embodiment of the present invention;

[0051] Figure 10 This is a schematic diagram of the surface creation reference points when the loop column consists of two lines, as provided in this embodiment of the invention.

[0052] Figure 11 This is a schematic diagram of UV control points when the ring column has two lines, as provided in this embodiment of the invention.

[0053] Figure 12 This is a schematic diagram of the grid surface constructed when the ring column consists of two lines, as provided in an embodiment of the present invention.

[0054] Figure 13 This is a schematic diagram of the surface creation reference points when the loop column has 3 lines, as provided in this embodiment of the invention;

[0055] Figure 14 This is a schematic diagram of UV control points when the ring column has 3 lines, as provided in an embodiment of the present invention;

[0056] Figure 15 This is a schematic diagram of the NURBS surface when the loop column has 3 lines, as provided in the embodiment of the present invention;

[0057] Figure 16 This is a schematic diagram of the surface creation reference points when the loop column has 4 lines, as provided in this embodiment of the invention;

[0058] Figure 17 This is a schematic diagram of reference points when the ring column has 4 lines, as provided in this embodiment of the invention;

[0059] Figure 18 This is a schematic diagram of UV control points and NURBS surface when the ring column has 4 lines, provided by an embodiment of the present invention;

[0060] Figure 19 This invention provides an industrial mold curved surface filling device.

[0061] Figure 20 This is a schematic diagram of the structure of a terminal provided in an embodiment of the present invention;

[0062] Figure 21 This is a schematic diagram of the structure of a server provided in an embodiment of the present invention. Detailed Implementation

[0063] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0064] It should be noted that the following detailed description is illustrative and intended to provide further explanation of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0065] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0066] While surface filling technology is widely used in industrial mold surface design, existing techniques still have some shortcomings. Taking automotive mold surface design as an example, surface filling is a crucial technique in various aspects of automotive mold design. It transforms contour boundaries into smooth, continuous surfaces, meeting the aesthetic and aerodynamic requirements of automotive exteriors. It also allows for the design of surfaces that conform to human comfort and ease of operation, based on ergonomic principles. Furthermore, it helps designers create precise surface models, facilitating subsequent mold design and manufacturing. However, due to the irregular curvature variations and complex geometric shapes inherent in complex automotive surfaces, surface filling algorithms may not be able to perfectly match every detail, resulting in minute gaps or discontinuities at the boundaries, affecting the overall accuracy and appearance quality of the surface. The contour boundaries of complex automotive surfaces are often highly complex, containing numerous details and irregular shapes. For such complex boundaries, surface filling algorithms require extensive computation and iteration to generate suitable surfaces, leading to excessively long computation times, especially when dealing with large-scale automotive surface models, which may affect design and development efficiency. Surface filling parameter settings are also complex; for example, ensuring the continuity between the filled surface and adjacent curves relies on the designer's experience and knowledge. Low continuity can cause visual discontinuity and compromise the surface quality of the vehicle model.

[0067] This invention provides a method and system for filling curved surfaces in industrial molds. It can perform a series of fully automated processes, including automatic retrieval of continuous lines, line array repair, ring line array judgment, ring line array segmentation, curved surface filling, and curved surface adjustment. This reduces the reliance on the professional knowledge and experience of designers and achieves fast and high-quality curved surface filling.

[0068] Please refer to Figure 1 This document illustrates a flowchart of an industrial mold surface filling method according to an embodiment of the present invention. This industrial mold surface filling method can be applied to a computer-aided industrial mold surface design system. The industrial mold surface filling method includes the following steps:

[0069] Step 101: In response to the type selection command, automatically retrieve the corresponding loop column information based on the selected type;

[0070] In this embodiment, if the response type is a sheet body, the topology information of all sheets body is automatically retrieved, and the inner ring boundary line information is obtained based on the topology information of all sheets body.

[0071] If the response type is boundary line or line, automatically retrieve the connected loop column;

[0072] Understandably, a sheet can be a curved surface model or a thin sheet entity. These curved surface models or thin sheet entities may include information such as faces, edges, and loops. For each sheet, there is usually an outer loop and several inner loops. The inner loops represent holes in the face, so it is necessary to extract the boundary lines of all inner loops (i.e., the edges that make up the inner loops).

[0073] Step 102: Determine if there are errors in the loop column. If so, automatically repair it into a loop column. If the repair is successful, automatically segment it into a polygonal outline based on the relevant information of the successfully repaired loop column. If there are no errors, directly segment it into a polygonal outline based on the relevant information of the loop column.

[0074] In this embodiment, the system determines whether there are errors in the loop line column based on the set judgment criteria. For example, if there are problems such as separation, intersection, or overlap of the line column, it is determined that there are errors in the loop line column and it needs to be repaired. Otherwise, based on information such as the curvature, line length, control points, tangent direction and normal direction of the points on the curve in the loop line column, auxiliary points and auxiliary lines are added to divide the loop line column into a four-sided contour. If there are less than four sides, it is divided into a three-sided contour or a two-sided contour together with the four sides of the previous group.

[0075] Furthermore, if the repair fails, return to re-evaluate whether there are errors in the circular column.

[0076] Step 103: Draw the segmented quadrilateral contours as NURBS surfaces;

[0077] Step 104: Determine if there are adjacent faces in the loop column. If they exist, obtain the information of the adjacent faces and lines, and automatically adjust the control points and weights of the NURBS surface to maintain a certain continuity between the surface and the adjacent faces. If they do not exist, return to step 102.

[0078] In summary, the industrial mold surface filling method provided by the embodiments of the present invention improves the quality and speed of industrial mold surface design.

[0079] Please refer to Figure 2 , Figure 2 This is a schematic diagram of the inner ring boundary of the sheet body, as shown below. Figure 2 As shown, in step 101, if the response type is a sheet, the topology information of all sheets is automatically retrieved, and the inner ring boundary information is obtained based on the topology information of all sheets; the obtained inner ring boundary of the sheet includes inner ring 1 and inner ring 2.

[0080] Please refer to Figures 3-6 For reference diagrams on determining circular columns, see below. Figure 3 The diagram shown is a reference diagram for judging the separation of loop lines. In it, 1, 2, 3... represent lines, a, b, c... represent endpoints, and (1), (2), (3)... represent loops.

[0081] Select a boundary line or line, determine the starting and ending points, repair separated, intersecting, and coincident lines, and form a closed loop of a set of boundary lines or line sequences as a loop.

[0082] Specifically, in step 102, if the line array is separated, intersecting, overlapping, or the number of lines in a group of loop lines exceeds the set number, it is determined that there is an error in the loop line array;

[0083] Specifically, in step 102, if the line array is separated, the repair process includes:

[0084] If the line sequence is separated, determine whether the distance between two adjacent endpoints is less than the set distance tolerance. If it is satisfied, the line sequence is determined to be a continuous line; otherwise, the line sequence is determined to be a non-continuous line.

[0085] Specifically, line L1 has a starting point S1 and an ending point E1, and line L2 has a starting point S2 and an ending point E2. If the distance between S1 and S2 is less than a set distance tolerance, or the distance between S1 and E2 is less than a set distance tolerance, or the distance between E1 and S2 is less than a set distance tolerance, or the distance between E1 and E2 is less than a set distance tolerance, then L1 and L2 are considered continuous lines. Otherwise, L1 and L2 are considered discontinuous.

[0086] In this embodiment, the distance tolerance can be set manually, such as 0.01mm;

[0087] The specified error can be set manually, such as 0.05mm;

[0088] Please see Figure 3 , Figure 3If the distance between the endpoints of a line is less than the set distance tolerance, then the line is considered a continuous line.

[0089] The ends of the lines are connected to form a loop, such as... Figure 3 The loop (1) is formed by line segments 1, 2, 3, and 4.

[0090] Even if the endpoints are inconsistent, they are still considered connected if the distance is within the specified error.

[0091] like Figure 3 If the distance between the midpoints a and b is less than the specified error, the loop formed by lines 4, 5, 6, and 7 is (2); otherwise, if the distance between the endpoints is greater than the specified error, it is determined that it is not a loop. For example, the endpoints... c , d If the distance is greater than the specified error, the line sequence 3, 8, 9, and 10 cannot form a loop.

[0092] Specifically, in step 102, if it is determined that the loop columns intersect, the loop column repair process includes:

[0093] If two lines intersect, the intersection point is taken as the new endpoint. If a set of lines intersect, the intersection point is taken as the new endpoint. For example... Figure 4 As shown, the endpoints of lines 11 and 12 are... e , f Updated to intersection point g , forming a ring (4).

[0094] Figure 5 This is a reference diagram for determining the overlap of circular lines. If overlapping lines exist, the redundant lines are discarded. Figure 5 In the middle, 19 (endpoints) are not connected in a loop. h , i ), directly discard. If 19 and 16 (endpoints) h , j Since the starting and ending points also coincide, one of them can be discarded. The remaining 15, 16, 17, and 18 form a ring (5).

[0095] Specifically, in step 102, if the number of lines in a set of loop lines exceeds the set number, the curvature and tangent direction of each curve at its endpoints are calculated. If the curvature error between two adjacent curves at their endpoints is within a certain range (the curvature error threshold is usually set to 5%), and the angle between their tangent directions is less than a set angle, such as 5°, then these two adjacent curves can be integrated into one line. Continuous data points (including points in overlapping areas) of adjacent curves are collected, and cubic spline interpolation (ensuring the continuity of the second derivative) is used for fitting to generate a one-line curve. The one-line line group and the remaining line groups are then combined to form a loop.

[0096] If, after processing, the number of lines in a group still exceeds the set number, the lines will be grouped, auxiliary lines will be added, and then loops will be formed.

[0097] like Figure 6 As shown, if the number of lines in a group is 5 and is set to no more than 4, then the line group will be converted into a single line based on information such as curvature and line direction. Figure 6 In the middle, after 24 and 20 are simplified, they form a ring with 21, 22 and 23 (6).

[0098] like Figure 7 As shown, if the number of lines in a group still exceeds 4 after the line-simplification process, the lines will be grouped into groups of 4. Figure 7 In the middle, after 25, 26, and 27 are converted into 32, the number of lines is 5; then, according to the line length, curvature, and other information, auxiliary line 33 is added to divide it into 2 contours, 30, 31, 32, and 33 are loops (7), and 28, 29, and 33 are loops (8).

[0099] It should be noted that during automatic grouping, the location of auxiliary lines is determined based on priority: larger curvature error, larger tangent angle, and larger line length difference. Figure 7 The auxiliary lines added in the code are the result of automatic judgment; the effect of auxiliary lines at other endpoints is much worse.

[0100] In step 103, in order to make more precise adjustments to the surface, the segmented four-sided contours are drawn as NURBS surfaces;

[0101] Obtain information such as the number, curvature, line length, tangent direction and normal direction of points on the curve of the loop boundary lines, and adjust the loop boundary lines to have 4 sides for processing.

[0102] When importing data, curves and other line columns are easily divided into countless small line segments, resulting in an uncertainty in the number of loop line columns.

[0103] Specifically, the steps include the following:

[0104] Step 301: When the number of circular lines is less than the set number of lines, force the circular lines to be converted into a single line. If they cannot be converted into a single line, process them as separate lines.

[0105] For example, if the inner loop consists of line segments with sharp angles between adjacent segments, it cannot be processed as a single line. Therefore, it is divided into different numbers of curves based on the line length and curvature. For example... Figure 8 The diagrams shown are schematics illustrating the number of curves in the loop columns of 2, 3, and 4, respectively.

[0106] Step 302: If the number of loops after the one-line processing exceeds the set number, such as 4, add auxiliary points and auxiliary lines for segmentation, ultimately forming a four-sided loop, such as... Figure 9 As shown.

[0107] The following describes the surface creation under the conditions of lines 2, 3, and 4 mentioned above:

[0108] like Figure 10 , Figure 11 and Figure 12 As shown, when the number of circular columns is 2, it specifically includes:

[0109] a) Calculate the centers of the two curves and the midpoint between the two centers;

[0110] b) Determine the division points by dividing the two curves into the number of parts based on information such as curvature and control points;

[0111] For example, determine that the curves are divided into three equal parts, and draw a temporary triangular plane using the first third point of the two curves and the midpoint calculated in a). The centroid of this plane is used as the "star point"; draw another temporary triangular plane using the second third point of the two curves and the midpoint calculated in a). The centroid of this plane is used as another control point.

[0112] c) Calculate the segmentation points again based on the curves after segmentation.

[0113] d) Based on the boundary seam requirements, create auxiliary curves (dashed lines), and use the intersection points (references) of each pair as UV control points.

[0114] e) Create a NURBS surface based on UV.

[0115] like Figure 13 , Figure 14 and Figure 15 As shown, when the number of circular columns is 3, it specifically includes:

[0116] a) Calculate the centers of the three curves and draw a temporary triangular plane with the three midpoints. The centroid of this plane is used as the "star point".

[0117] b) Divide the three curves at their midpoints, and then calculate the division points for each of the divided curves. The division points are set according to requirements.

[0118] c) Create auxiliary curves according to the boundary joint requirements, and use the intersection points of each pair as UV control points.

[0119] d) Create a NURBS surface based on UV.

[0120] like Figure 16 , Figure 17 and Figure 18 As shown, when the number of circular columns is 4, it specifically includes:

[0121] a) Calculate the centers of the four curves and draw a temporary plane using the four midpoints. If they are not coplanar, draw a boundary plane. The centroid of this plane is designated as a "star point".

[0122] b) Calculate the segmentation points again based on the curves after segmentation.

[0123] c) Based on the boundary seam requirements, create auxiliary curves (dashed lines), and use the intersection points (references) of each pair as UV control points.

[0124] d) Create a NURBS surface based on UV.

[0125] In step 104, information about adjacent surfaces and boundary lines is obtained, and the positions of the control points of the NURBS surface are automatically adjusted to change the surface so that it remains continuous with adjacent surfaces at G0, G1 or G2 on the specified boundary line.

[0126] In this embodiment, the least squares method or iterative optimization method can be used to automatically adjust the control points of the NURBS surface. The specific adjustment process is described below using the two methods.

[0127] When using the least squares method, the specific steps include:

[0128] Constructing the error function: Transform the continuity condition of G1 or G2 into an error function.

[0129] For example, for G1 continuity, the error function E can be defined as the sum of the squares of the position error and the tangential error:

[0130] ,

[0131] in, This indicates the first curve on the parametric section. At, with parameters Describing the position vector This indicates the second curve on the parametric section. place, and Corresponding to the same slice, same parameters Comparison position vector Indicates the first curve at Section, parameters Regarding parameters tangent vector This indicates that the second curve is in Section, parameters Regarding parameters tangent vector The scaling factor (scalar function) represents the ratio of the magnitudes of the tangent vectors of two curves. The parameter value representing the upper bound of the integration interval usually indicates the position of a parameter of the second curve after the connection point (or the parameter extension boundary of the first curve), which is specifically determined by the parameterization range of the curve. Indicates that the two curves are in The parameter values ​​of the common connection points on the cross section (i.e. the parameters corresponding to the connection points of adjacent curves).

[0132] For G2 continuity, a curvature error term also needs to be added.

[0133] Solve for the control points of the error function E with respect to the NURBS surface. Sum of weights Find the partial derivatives, set them to zero, and you will get a set of linear or nonlinear equations. Solve the equations to get the adjusted control points and weight factors.

[0134] When using iterative optimization methods, the specific methods include:

[0135] Initialization: Given an initial control point and weighting factors .

[0136] Error calculation: In the t-th iteration, calculate the position error, tangential error (G1 continuous), and curvature error (G2 continuous) of the current surface on the common boundary line.

[0137] Calculate the adjustment amount: Based on the error situation, use optimization algorithms such as gradient descent and Newton's method to calculate the adjustment amount of the control points and weight factors. and For example, in gradient descent, the adjustment amount is proportional to the negative gradient of the error function.

[0138] Update parameters: Update control points and weighting factors , .

[0139] Termination condition: Repeat the above steps until the error is less than a predetermined threshold or the maximum number of iterations is reached.

[0140] The method of this invention enables fully automated batch filling of curved surfaces, reducing manual judgment and adjustment, significantly shortening the creation time of complex curved surfaces, and improving design efficiency. Simultaneously, it can automatically adjust the surface control points to ensure smoothness with adjacent surfaces. This avoids users manually adjusting surface parameters and prevents designers from failing to achieve the desired surface effect due to insufficient professional knowledge and experience.

[0141] Please refer to Figure 19 The diagram illustrates a structural block diagram of an industrial mold surface filling device according to another embodiment of the present invention. This industrial mold surface filling device can be applied to a computer-aided industrial mold surface design system. The industrial mold surface filling device includes:

[0142] Automatic retrieval module 1901 is used to automatically retrieve the corresponding ring column information according to the selected type in response to the type selection instruction;

[0143] The loop column repair module 1902 is used to determine whether there is an error in the loop column. If so, it is automatically repaired into a loop column. If the repair is successful, it is automatically segmented into a polygonal contour based on the relevant information of the successfully repaired loop column. If there is no error, it is directly segmented into a polygonal contour based on the relevant information of the loop column.

[0144] The surface drawing module 1903 is used to draw the segmented polygonal contours into NURBS surfaces.

[0145] The surface adjustment module 1904 is used to determine whether there are adjacent surfaces in the loop line column. If there are, it obtains the information of the adjacent surfaces and lines, and automatically adjusts the control points and weights of the NURBS surface to maintain a certain continuity between the surface and the adjacent surfaces.

[0146] Figure 20 A schematic diagram of a terminal 2000 provided in an exemplary embodiment of this application is shown. The terminal 2000 can be used to perform the steps executed by the computer device in the above-described industrial mold surface filling method.

[0147] Typically, terminal 2000 includes a processor 2001 and a memory 2002.

[0148] Processor 2001 may include one or more processing cores, such as a quad-core processor, an octa-core processor, etc. Processor 1901 may be implemented using at least one hardware form selected from DSP (Digital Signal Processing), FPGA (Field Programmable Gate Array), and PLA (Programmable Logic Array). Processor 2001 may also include a main processor and a coprocessor. The main processor, also known as a CPU (Central Processing Unit), is used to process data in the wake-up state; the coprocessor is a low-power processor used to process data in the standby state. In some embodiments, processor 2001 may integrate a GPU (Graphics Processing Unit), which is responsible for rendering and drawing the content required to be displayed on the screen. In some embodiments, processor 2001 may also include an AI (Artificial Intelligence) processor, which is used to handle computational operations related to machine learning.

[0149] The memory 2002 may include one or more computer-readable storage media, which may be non-transitory. The memory 2002 may also include high-speed random access memory and non-volatile memory, such as one or more disk storage devices or flash memory devices. In some embodiments, the non-transitory computer-readable storage media in the memory 2002 are used to store at least one instruction, which is used by the processor 2001 to implement the industrial mold surface filling method provided in the method embodiments of this application.

[0150] In some embodiments, the device 2000 may also optionally include a peripheral device interface 2003 and at least one peripheral device. The processor 2001, memory 2002, and peripheral device interface 2003 can be connected to each other via a bus or signal line. Each peripheral device can be connected to the peripheral device interface 2003 via a bus, signal line, or circuit board.

[0151] Those skilled in the art will understand that Figure 20 The structure shown does not constitute a limitation on terminal 2001 and may include more or fewer components than shown, or combine certain components, or use different component arrangements.

[0152] Figure 21 This is a schematic diagram of a server structure provided in an embodiment of this application. The server 2100 can vary significantly due to different configurations or performance. It may include one or more Central Processing Units (CPUs) 2101 and one or more memories 2102. The memories 2102 store at least one instruction, which is loaded and executed by the processor 2101 to implement the methods provided in the various method embodiments described above. Of course, the server 2100 may also have wired or wireless network interfaces, a keyboard, and input / output interfaces for input and output. The server may also include other components for implementing device functions, which will not be elaborated upon here.

[0153] Server 2100 can be used to perform the steps executed by the computer device in the above-described industrial mold surface filling method.

[0154] This application also provides a computer device for an industrial mold surface filling method. The computer device includes a processor and a memory. The memory stores at least one instruction, which is loaded and executed by the processor to implement the parametric mesh-based surface trimming method of the above embodiments.

[0155] This application also provides a computer program product including computer instructions stored in a computer-readable storage medium. A processor of a computer device reads the computer instructions from the computer-readable storage medium and executes the computer instructions, causing the computer device to perform the aforementioned industrial mold surface filling method.

[0156] Those skilled in the art will understand that all or part of the steps of the above embodiments can be implemented by hardware or by a program instructing related hardware. The program can be stored in a computer-readable storage medium, such as a read-only memory, a disk, or an optical disk.

[0157] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method of filling a curved surface of an industrial mold, characterized by, The method comprises the following steps: in response to a type selection instruction, automatically retrieving corresponding ring line information according to the selected type; determining whether the ring line has errors, and if so, automatically repairing the ring line, and if the repair is successful, automatically segmenting the ring line into a multi-edge contour according to the relevant information of the repaired ring line, and if there are no errors, directly segmenting the ring line into a multi-edge contour according to the relevant information of the ring line; drawing the segmented multi-edge contour into a NURBS surface; determining whether the ring line has adjacent surfaces, and if so, obtaining the information of the adjacent surfaces and lines, and automatically adjusting the control points and weights of the NURBS surface to maintain a certain continuity between the surface and the adjacent surfaces; wherein, if the ring line has errors, the process of automatically repairing the ring line comprises: if the line has separation, determining whether the distance between the two end points close to the line is less than the set distance tolerance, and if so, determining that the line is continuous; if not, determining that the line is not continuous; if the two lines intersect, obtaining the intersection point as a new end point; if there are coincident lines, discarding the redundant line; if the number of lines in a group of lines exceeds the set number, one-lining the line according to the relevant information of the ring line, and grouping the one-lined line and the remaining lines into a ring; if the number of lines in a group of lines still exceeds the set number after one-lining, grouping the lines, adding auxiliary lines, and then grouping the lines into a ring; wherein, the automatic segmentation of the ring line into a multi-edge contour comprises: if the number of lines in a group of lines exceeds the set number, calculating the curvature and tangent direction of each curve at the end point, and if the curvature error of the adjacent two curves at the end point is within the preset range and the tangent direction angle is less than the set angle, collecting the continuous data points of the adjacent curves to fit and generate a one-lined curve, and grouping the one-lined line and the remaining lines into a ring; if the number of lines in a group of lines still exceeds the set number after one-lining, grouping the lines, adding auxiliary lines, and then grouping the lines into a ring.

2. A method of filling a curved surface of an industrial mold as recited in claim 1, wherein, The automatic retrieval of corresponding ring line information in response to a type selection instruction comprises: if the response type is a sheet, automatically retrieving the topological structure information of all sheets, and obtaining the inner ring boundary line information according to the topological structure information of all sheets; if the response type is a boundary line or a line, automatically retrieving the connected ring line.

3. A method for filling a curved surface of an industrial mold as recited in claim 1, wherein The determination basis for determining whether the ring line has errors is that if the line has separation, intersection, coincidence, or the number of lines in a group of lines exceeds the set number, the ring line is determined to have errors.

4. A method for filling a curved surface of an industrial mold as recited in claim 1, wherein In the automatic adjustment of the control points and weights of the NURBS surface, the least square method or the iterative optimization method can be used.

5. An industrial mold curved surface filling device characterized by comprising: It comprises: an automatic retrieval module for automatically retrieving corresponding ring line information according to the selected type in response to a type selection instruction; a ring line repair module for determining whether the ring line has errors, and if so, automatically repairing the ring line, and if the repair is successful, automatically segmenting the ring line into a multi-edge contour according to the relevant information of the repaired ring line, and if there are no errors, directly segmenting the ring line into a multi-edge contour according to the relevant information of the ring line; If the ring line column has errors, the automatic repairing process includes: If the line column has separation, it is determined whether the distance between the two end points of the line column is less than the set distance tolerance, if yes, the line column is determined to be continuous; if not, the line column is determined to be not continuous; If the two lines intersect, the intersection point is obtained as a new end point; If there are overlapping lines, the redundant line column is discarded; If the number of lines in the ring line column exceeds the set number, the line column is one-ized according to the related information of the line column in the ring, and the one-ized line column and the remaining line column form a ring; if the number of lines in the line column still exceeds the set number after the one-ization processing, the line is grouped, and the ring is formed after adding auxiliary lines; The automatic segmentation into a multi-edge contour according to the related information of the line column in the ring includes: If the number of lines in the ring line column exceeds the set number, the curvature and tangent direction of each curve at the end point are calculated, if the curvature error of the adjacent two curves at the end point is within the preset range, and the tangent direction angle is less than the set angle, the continuous data points of the adjacent curves are collected and fitted to generate a one-ized curve, and the one-ized line column and the remaining line column form a ring; If the number of lines in the line column still exceeds the set number after the one-ization processing, the line is grouped, and the ring is formed after adding auxiliary lines; A surface drawing module is used to draw the segmented multi-edge contour into a NURBS surface; A surface adjustment module is used to determine whether there are adjacent surfaces in the ring line column, if yes, the information of the adjacent surfaces and the line is obtained, the control points and weights of the NURBS surface are automatically adjusted to make the surface and the adjacent surface maintain a certain continuity.

6. A computer-readable storage medium having stored thereon a computer program, characterized in that, The program is executed by the processor to realize the steps in the industrial mold surface filling method of any one of claims 1-4.

7. A computer device comprising a memory, a processor, and a computer program stored on the memory and executable on the processor, characterized in that, The processor executes the program to realize the steps in the industrial mold surface filling method of any one of claims 1-4.

8. A program product, the program product being a computer program product comprising a computer program, characterized in that The computer program is executed by the processor to realize the steps in the industrial mold surface filling method of any one of claims 1-4.

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