Method and apparatus for measuring area of three-dimensional face model, electronic device, and storage medium

Abstract

The present application provides a method and apparatus for measuring the area of a three-dimensional face model, an electronic device, and a storage medium. In the method, a user can perform point selection operations on a three-dimensional face model to be measured, to obtain ordered three-dimensional control points. Then, a three-dimensional closed edge line is generated on the basis of the plurality of ordered three-dimensional control points. Finally, the area of a three-dimensional mesh region to be measured of said three-dimensional face model enclosed by the three-dimensional closed edge line is measured. That is, the surface area of the three-dimensional face model is measured by adding the control points to close the edge line. The operation is simple and visualized. The determined three-dimensional mesh region to be measured is continuous. Moreover, the method of automatically generating the three-dimensional control points by means of the point selection operations has high precision, and the finally obtained three-dimensional closed edge line and said three-dimensional mesh region enclosed by the three-dimensional closed edge line are more accurate.

Description

Methods, devices, electronic equipment, and storage media for measuring the area of ​​3D facial models Cross-reference to related applications

[0001] This application claims priority to Chinese Patent Application No. 202411586231.5, filed on November 7, 2024, entitled "Method, Apparatus, Electronic Device and Storage Medium for Measuring Area of ​​3D Face Model", the entire contents of which are incorporated herein by reference. Technical Field

[0002] This application relates to the field of measurement technology, and in particular to a method, apparatus, electronic device, and storage medium for measuring the area of ​​a three-dimensional face model. Background Technology

[0003] Currently, area measurement products typically involve selecting the area to be measured on a 3D model using a brush, as shown in Figure 1. The software then automatically measures the area based on the selected region.

[0004] The above method of selecting the area to be measured using a brush is prone to penetration, meaning that the selected area lacks continuity; in addition, it is difficult to select the area to be measured at the turning point using a brush.

[0005] In summary, traditional methods for measuring the area of ​​3D models suffer from technical problems such as complex operation, lack of continuity in the selected area, and poor accuracy during brush operation when selecting the area to be measured. Summary of the Invention

[0006] In view of this, the present application provides a method, apparatus, electronic device and storage medium for measuring the area of ​​a three-dimensional face model, so as to alleviate the technical problems of traditional three-dimensional model area measurement methods, such as complicated operation when selecting the area to be measured, lack of continuity of the selected area to be measured, and poor accuracy when using brush operation.

[0007] In a first aspect, embodiments of this application provide a method for measuring the area of ​​a 3D face model, comprising: loading and displaying a 3D face model to be measured in a planar display area; generating ordered 3D control points based on user point selection operations on the 3D face model to be measured, and displaying them on the display plane; wherein the order of the 3D control points is related to the order of user point selection operations; the 3D control points are rays extending from the point selection operation positions displayed on the display plane, perpendicular to the display plane and pointing to the 3D face model to be measured, and the first intersection point of the ray with the 3D face model to be measured; generating 3D closed edge lines based on multiple ordered 3D control points; determining the 3D mesh region to be measured of the 3D face model to be measured enclosed by the 3D closed edge lines; and measuring the area of ​​the 3D mesh region to be measured to obtain the area of ​​the 3D mesh region to be measured.

[0008] Furthermore, a three-dimensional closed edge line is generated based on multiple ordered three-dimensional control points, including: generating the current three-dimensional edge line between the current three-dimensional control point and the previous three-dimensional control point using spline curves, and optimizing all the generated three-dimensional edge lines based on the current three-dimensional control point to make the three-dimensional edge lines on both sides of each three-dimensional control point transition smoothly, until the current three-dimensional control point is the starting point of the three-dimensional control point, thus obtaining the three-dimensional closed edge line.

[0009] Furthermore, a three-dimensional closed edge line is generated based on multiple ordered three-dimensional control points, including: generating the current three-dimensional edge line between the current three-dimensional control point and the previous three-dimensional control point using spline curves, and optimizing the previous three-dimensional edge line based on the current three-dimensional control point to make the three-dimensional edge lines on both sides of the current three-dimensional control point transition smoothly until the current three-dimensional control point becomes the starting point of the three-dimensional control point, thus obtaining the three-dimensional closed edge line.

[0010] Furthermore, the current 3D edge line is generated between the current 3D control point and the previous 3D control point using spline curves, including: if the distance between the current 3D control point and the previous 3D control point is greater than a preset distance threshold, an additional 3D control point is generated between the current 3D control point and the previous 3D control point; the current 3D edge line is generated between the previous 3D control point, the additional 3D control point and the current 3D control point using spline curves.

[0011] Furthermore, determining the 3D mesh region of the 3D face model to be measured, enclosed by the 3D closed edge line, includes: determining the extreme point of the 3D edge line in a first target direction, where the first target direction is arbitrary; traversing the 3D closed edge line along a second target direction starting from the extreme point of the 3D edge line, and traversing along the outer 3D edge line when a fork occurs, until returning to the extreme point of the 3D edge line, to obtain the maximum region enclosed by the 3D closed edge line, where the second target direction includes any of the following directions: clockwise direction and counterclockwise direction; and taking the maximum region enclosed by the 3D closed edge line as the 3D mesh region of the 3D face model to be measured, enclosed by the 3D closed edge line.

[0012] Furthermore, the area measurement of the three-dimensional mesh region to be measured includes: if the first target triangle in the three-dimensional mesh region to be measured is not divided by a three-dimensional closed edge line, then the area of ​​the first target triangle is calculated based on the three-dimensional coordinates of its vertices; if the second target triangle in the three-dimensional mesh region to be measured is divided by a three-dimensional closed edge line, then the second target triangle is subdivided into second target sub-triangles using the three-dimensional edge line used for division as the dividing line, and the area of ​​the second target sub-triangle is calculated based on the three-dimensional coordinates of its vertices, wherein the second target sub-triangle is a triangle located within the three-dimensional mesh region to be measured; the area of ​​the three-dimensional mesh region to be measured is calculated based on the area of ​​the first target triangle and the area of ​​the second target sub-triangle.

[0013] Furthermore, the method also includes: adjusting the position of the target 3D control point based on the user's drag operation on the target 3D control point on the 3D closed edge line; updating the 3D closed edge line based on the adjusted position of the target 3D control point; determining the updated 3D mesh region of the face model to be measured enclosed by the updated 3D closed edge line based on the updated 3D closed edge line; and measuring the area of ​​the updated 3D mesh region to be measured to obtain the area of ​​the updated 3D mesh region to be measured.

[0014] Furthermore, the method also includes: determining the two endpoints of the three-dimensional edge line closest to the new three-dimensional control point based on the user's operation of adding a new three-dimensional control point on the three-dimensional closed edge line, and calculating the nearest point of the line segment formed by the new three-dimensional control point and the two endpoints; determining whether the length from the new three-dimensional control point to the nearest point is less than the preset line segment width; if it is less, determining that the new three-dimensional control point is projected onto the nearest three-dimensional edge line, and completing the operation of adding a new three-dimensional control point on the nearest three-dimensional edge line.

[0015] Furthermore, the method also includes: deleting the target 3D control points based on the user's deletion operation on the target 3D control points on the 3D closed edge line; updating the 3D closed edge line based on the remaining 3D control points on the 3D closed edge line; determining the updated 3D mesh region of the face model to be measured enclosed by the updated 3D closed edge line based on the updated 3D closed edge line; and measuring the area of ​​the updated 3D mesh region to be measured to obtain the area of ​​the updated 3D mesh region to be measured.

[0016] Secondly, embodiments of this application also provide an area measurement device for a three-dimensional face model, comprising: a first generation unit configured to load and display a three-dimensional face model to be measured in a planar display area, and generate ordered three-dimensional control points based on the user's point selection operation on the three-dimensional face model to be measured, and display them on the display plane, wherein the order between the three-dimensional control points is related to the order of the user's point selection operation, the three-dimensional control points are rays extending from the point selection operation positions displayed on the display plane, perpendicular to the display plane and pointing to the three-dimensional face model to be measured, and the first intersection point of the ray with the three-dimensional face model to be measured; a second generation unit configured to generate three-dimensional closed edge lines based on multiple ordered three-dimensional control points; a determination unit configured to determine the three-dimensional mesh region to be measured of the three-dimensional face model to be measured surrounded by the three-dimensional closed edge lines; and an area measurement unit configured to measure the area of ​​the three-dimensional mesh region to be measured to obtain the area of ​​the three-dimensional mesh region to be measured.

[0017] Thirdly, embodiments of this application also provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method described in any of the first aspects above.

[0018] Fourthly, embodiments of this application also provide a computer-readable storage medium storing machine-executable instructions, which, when invoked and executed by a processor, cause the processor to perform the method described in any of the first aspects above.

[0019] In this embodiment, a method for measuring the area of ​​a 3D face model is provided, comprising: loading and displaying a 3D face model to be measured in a planar display area; generating ordered 3D control points based on user point selection operations on the 3D face model to be measured, and displaying them on the display plane; wherein the order of the 3D control points is related to the order of user point selection operations; the 3D control points are rays extending from the point selection operation positions displayed on the display plane, perpendicular to the display plane and pointing to the 3D face model to be measured, and the first intersection point of the ray with the 3D face model to be measured; generating 3D closed edge lines based on multiple ordered 3D control points; determining the 3D mesh region to be measured of the 3D face model to be measured enclosed by the 3D closed edge lines; and measuring the area of ​​the 3D mesh region to be measured to obtain the area of ​​the 3D mesh region to be measured. As described above, in the method for measuring the area of ​​a 3D face model in this application, the user can perform point selection operations on the 3D face model to be measured, thereby obtaining ordered 3D control points. Then, based on multiple ordered 3D control points, a 3D closed edge line is generated. Finally, the area of ​​the 3D mesh region of the 3D face model to be measured, which is surrounded by the 3D closed edge line, is measured. That is, the surface area of ​​the 3D face model is measured by adding control points and closing the edge line. The operation is simple and visual. The determined 3D mesh region to be measured is continuous. Moreover, the method of automatically generating 3D control points through point selection is highly accurate. The final obtained 3D closed edge line and the 3D mesh region to be measured surrounded by the 3D closed edge line are more accurate. This alleviates the technical problems of traditional 3D model area measurement methods, such as complex operation when selecting the region to be measured, lack of continuity of the selected region to be measured, and poor accuracy when using brush operations. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the specific embodiments or related technologies of this application, the drawings used in the description of the specific embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 is a schematic diagram of selecting the area to be measured on a 3D model using a brush, provided by traditional techniques.

[0022] Figure 2 is a flowchart of a method for measuring the area of ​​a three-dimensional face model provided in an embodiment of this application;

[0023] Figure 3 is a schematic diagram of the generation of ordered three-dimensional control points provided in an embodiment of this application;

[0024] Figure 4 is a schematic diagram of a three-dimensional closed edge line in the case of self-intersection of three-dimensional edge lines provided in the embodiments of this application;

[0025] Figure 5 is a schematic diagram of a three-dimensional closed edge line in the case where the three-dimensional edge lines do not intersect, provided in an embodiment of this application;

[0026] Figure 6 is a schematic diagram of the three-dimensional control points for dragging the target provided in an embodiment of this application;

[0027] Figure 7 is a schematic diagram of adding, dragging, and deleting control points provided in an embodiment of this application;

[0028] Figure 8 is a schematic diagram of an area measurement device for a three-dimensional face model provided in an embodiment of this application;

[0029] Figure 9 is a schematic diagram of an electronic device provided in an embodiment of this application. Detailed Implementation

[0030] The technical solutions of this application will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] Traditional methods for measuring the area of ​​3D models are complex to operate when selecting the area to be measured, lack continuity in the selected area, and have poor accuracy when using brushes.

[0032] Based on this, in the method for measuring the area of ​​a 3D face model in this application, the user can perform point selection operations on the 3D face model to be measured, thereby obtaining ordered 3D control points. Then, based on multiple ordered 3D control points, a 3D closed edge line is generated. Finally, the area of ​​the 3D mesh region of the 3D face model to be measured, which is surrounded by the 3D closed edge line, is measured. That is, the surface area of ​​the 3D face model is measured by adding control points and closing the edge line. The operation is simple and visual. The determined 3D mesh region to be measured is continuous. Moreover, the method of automatically generating 3D control points through point selection is highly accurate. The final 3D closed edge line and the 3D mesh region to be measured surrounded by the 3D closed edge line are more accurate.

[0033] To facilitate understanding of this embodiment, a method for measuring the area of ​​a three-dimensional face model disclosed in this application will be described in detail first.

[0034] Example 1:

[0035] According to an embodiment of this application, an embodiment of a method for measuring the area of ​​a three-dimensional face model is provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0036] Figure 2 is a flowchart of a method for measuring the area of ​​a 3D face model according to an embodiment of this application. As shown in Figure 2, the method includes the following steps:

[0037] Step S202: Load and display the 3D model of the face to be tested in the planar display area, and generate ordered 3D control points based on the user's point selection operation on the 3D model of the face to be tested, and display them on the display plane. The order of the 3D control points is related to the order of the user's point selection operation. The 3D control point is a ray that extends from the point selection operation position displayed on the display plane, is perpendicular to the display plane and points to the 3D model of the face to be tested, and is the first intersection point of the ray with the 3D model of the face to be tested.

[0038] In this embodiment, the method for measuring the area of ​​the aforementioned 3D face model can be implemented using 3D model area measurement software. When measuring the area of ​​the 3D face model to be measured, the software first loads and displays the 3D face model, as shown in Figure 3. The user can then perform point selection operations on the 3D face model. During point selection, ordered 3D control points (i.e., 3D model world coordinates) are generated. These point selection operations can be performed via mouse clicks, touch clicks, etc., resulting in 3D control point A as shown in Figure 3. Then, when the selected point position is floated to another location on the screen (i.e., the display plane), another point selection operation is performed to obtain 3D control point B. Subsequently, 3D control points C, D, E, F... are added sequentially until they are connected and closed with A. In this way, multiple ordered 3D control points related to the user's point selection sequence are obtained. Among these multiple ordered 3D control points, the starting and ending 3D control points are the same.

[0039] Step S204: Generate a three-dimensional closed edge line based on multiple ordered three-dimensional control points;

[0040] Specifically, in implementation, a three-dimensional closed edge line can be generated based on multiple ordered three-dimensional control points after all ordered three-dimensional control points have been generated. Alternatively, a three-dimensional edge line can be generated between each ordered three-dimensional control point and the previous three-dimensional control point. In this way, a three-dimensional closed edge line is finally obtained.

[0041] Step S206: Determine the three-dimensional mesh region to be measured of the three-dimensional face model surrounded by the three-dimensional closed edge line based on the three-dimensional closed edge line.

[0042] Step S208: Measure the area of ​​the three-dimensional mesh region to be measured to obtain the area of ​​the three-dimensional mesh region to be measured.

[0043] It should be noted that if there is another three-dimensional closed edge line inside the aforementioned three-dimensional closed edge line, then the three-dimensional mesh area to be measured should be the area enclosed by the two three-dimensional closed edge lines. When measuring the area, the difference between the area of ​​the three-dimensional mesh area to be measured enclosed by the outer three-dimensional closed edge line and the area of ​​the three-dimensional mesh area to be measured enclosed by the inner three-dimensional closed edge line is the area of ​​the area enclosed by the two three-dimensional closed edge lines, which is to say, the measurement of the void area is achieved.

[0044] In this embodiment, a method for measuring the area of ​​a 3D face model is provided, comprising: loading and displaying a 3D face model to be measured in a planar display area; generating ordered 3D control points based on user point selection operations on the 3D face model to be measured, and displaying them on the display plane; wherein the order of the 3D control points is related to the order of user point selection operations; the 3D control points are rays extending from the point selection operation positions displayed on the display plane, perpendicular to the display plane and pointing to the 3D face model to be measured, and the first intersection point of the ray with the 3D face model to be measured; generating 3D closed edge lines based on multiple ordered 3D control points; determining the 3D mesh region to be measured of the 3D face model to be measured enclosed by the 3D closed edge lines; and measuring the area of ​​the 3D mesh region to be measured to obtain the area of ​​the 3D mesh region to be measured. As described above, in the method for measuring the area of ​​a 3D face model in this application, the user can perform point selection operations on the 3D face model to be measured, thereby obtaining ordered 3D control points. Then, based on multiple ordered 3D control points, a 3D closed edge line is generated. Finally, the area of ​​the 3D mesh region of the 3D face model to be measured, which is surrounded by the 3D closed edge line, is measured. That is, the surface area of ​​the 3D face model is measured by adding control points and closing the edge line. The operation is simple and visual. The determined 3D mesh region to be measured is continuous. Moreover, the method of automatically generating 3D control points through point selection is highly accurate. The final obtained 3D closed edge line and the 3D mesh region to be measured surrounded by the 3D closed edge line are more accurate. This alleviates the technical problems of traditional 3D model area measurement methods, such as complex operation when selecting the region to be measured, lack of continuity of the selected region to be measured, and poor accuracy when using brush operations.

[0045] The above provides a brief overview of the area measurement method for the 3D face model in this application. The specific details involved are described in detail below.

[0046] In one optional embodiment of this application, generating a three-dimensional closed edge line based on a plurality of ordered three-dimensional control points specifically includes the following steps:

[0047] The current 3D edge line is generated between the current 3D control point and the previous 3D control point using spline curves. All generated 3D edge lines are then optimized based on the current 3D control point to make the transition of the 3D edge lines on both sides of each 3D control point smooth, until the current 3D control point becomes the starting point of the 3D control point, thus obtaining the 3D closed edge line.

[0048] In one optional embodiment of this application, generating a three-dimensional closed edge line based on a plurality of ordered three-dimensional control points specifically includes the following steps:

[0049] The current 3D edge line is generated between the current 3D control point and the previous 3D control point using spline curves. The previous 3D edge line is then optimized based on the current 3D control point to make the transition of the 3D edge lines on both sides of the current 3D control point smooth, until the current 3D control point becomes the starting point of the 3D control point, thus obtaining the 3D closed edge line.

[0050] Specifically, when a current 3D control point is generated, a spline curve is used to generate the current 3D edge line between the current 3D control point and the previous 3D control point. The previous 3D edge line is then optimized based on the current 3D control point to make the transition of the 3D edge lines on both sides of the current 3D control point smooth. Specifically, the 3D edge lines between 3D control points can be interpolated using spline curves until the current 3D control point is the starting point of the 3D control point, thus obtaining a 3D closed edge line.

[0051] In an optional embodiment of this application, a spline curve is used to generate the current 3D edge line between the current 3D control point and the previous 3D control point, specifically including the following steps:

[0052] (1) If the distance between the current 3D control point and the previous 3D control point is greater than the preset distance threshold, an additional 3D control point is generated between the current 3D control point and the previous 3D control point.

[0053] Specifically, the generation of additional 3D control points ensures that the distance between two adjacent 3D control points is less than a preset distance threshold.

[0054] The system has a preset distance threshold between two 3D control points. If the distance between the two 3D control points is greater than the preset distance threshold, additional 3D control points will be generated to ensure that the distance between adjacent 3D control points is not greater than the preset distance threshold. If the distance between the two 3D control points is too large, multiple additional 3D control points may be generated.

[0055] (2) Generate the current 3D edge line between the previous 3D control point, the additional 3D control point and the current 3D control point using spline curves.

[0056] Specifically, the generation of 2D edge lines is real-time and visualized, achieving "connecting wherever you point", and the transition after closure is smooth.

[0057] In one optional embodiment of this application, the measurement of the three-dimensional mesh region of the three-dimensional face model surrounded by the three-dimensional closed edge line is determined based on the three-dimensional closed edge line, specifically including the following steps:

[0058] (1) Determine the extreme point of the three-dimensional edge line in the first target direction based on the three-dimensional closed edge line, where the first target direction is any direction;

[0059] (2) Starting from the extreme point of the three-dimensional edge line, traverse the three-dimensional closed edge line along the second target direction, and when a fork occurs, traverse along the outer three-dimensional edge line until returning to the extreme point of the three-dimensional edge line, to obtain the largest area enclosed by the three-dimensional closed edge line. The second target direction includes any of the following directions: clockwise direction and counterclockwise direction.

[0060] (3) The largest area enclosed by the three-dimensional closed edge line is taken as the three-dimensional mesh area to be measured of the three-dimensional face model to be measured.

[0061] Specifically, to support users in editing 3D edge lines in any direction and arbitrarily intersecting 3D edge lines, careful handling is required when selecting the internal region of a 3D closed edge line. The maximum region enclosed by the 3D closed edge line can be obtained through the following steps:

[0062] 1) Select the extreme point of the 3D edge line: Randomly select the extreme point of the contour in any direction as the extreme point of the 3D edge line. If there are multiple extreme points of the 3D edge line, the direction can be randomly selected again.

[0063] 2) Starting from a selected extreme point of a three-dimensional edge line, traverse the three-dimensional closed edge line. When a fork occurs, follow the outer three-dimensional edge line (usually using the common rolling ball method).

[0064] 3) Until the extreme point of the three-dimensional edge line (i.e. the starting point) is finally reached, the outer contour of one circle is obtained, that is, the maximum area enclosed by the three-dimensional closed edge line is obtained, as shown in Figure 4. For the case of self-intersection of the three-dimensional edge line, the maximum enclosed area is taken for calculation.

[0065] In an optional embodiment of this application, the area measurement of the three-dimensional mesh region to be measured specifically includes the following steps:

[0066] (1) If the first target triangle in the three-dimensional mesh region to be measured is not divided by the three-dimensional closed edge line, the area of ​​the first target triangle is calculated based on the three-dimensional coordinates of the vertices of the first target triangle;

[0067] Specifically, the area of ​​the first target triangle is equal to half the size of the cross product of the vectors formed by the three-dimensional coordinates of each pair of vertices of the first target triangle.

[0068] (2) If the second target triangle in the three-dimensional mesh region to be measured is divided by a three-dimensional closed edge line, the second target triangle is subdivided into second target sub-triangles using the three-dimensional edge line used for division as the dividing line, and the area of ​​the second target sub-triangle is calculated based on the three-dimensional coordinates of the vertices of the second target sub-triangle, wherein the second target sub-triangle is a triangle located in the three-dimensional mesh region to be measured.

[0069] (3) Calculate the area of ​​the three-dimensional mesh region to be measured based on the area of ​​the first target triangle and the area of ​​the second target sub-triangle.

[0070] Specifically, as shown in Figure 5, after the three-dimensional edge lines are connected end-to-end and closed, the second target triangles intersecting with the three-dimensional edge lines are subdivided. For a given second target triangle, all intersecting three-dimensional edge lines are collected. Using these three-dimensional edge lines as dividing lines, this second target triangle is subdivided into smaller triangles (i.e., second target sub-triangles). By traversing the three-dimensional closed edge lines, all second target triangles near the three-dimensional edge lines can be subdivided, resulting in second target sub-triangles located within the area of ​​the three-dimensional mesh to be measured. Then, the area of ​​the second target sub-triangle is calculated based on the three-dimensional coordinates of its vertices. According to the formula: the area of ​​a triangle is equal to half the size of the cross product of the vectors formed by the three-dimensional coordinates of each pair of vertices, this is calculated by iterating through the triangles. Finally, the calculated areas of all first target triangles and all second target sub-triangles are summed to obtain the area of ​​the three-dimensional mesh area to be measured.

[0071] In an optional embodiment of this application, the method further includes the following steps:

[0072] (1) Adjust the position of the target 3D control point according to the user's drag operation on the target 3D control point on the 3D closed edge line;

[0073] (2) Update the three-dimensional closed edge line according to the adjusted position of the target three-dimensional control point;

[0074] (3) Determine the updated three-dimensional mesh region of the face model to be measured, which is surrounded by the updated three-dimensional closed edge line;

[0075] (4) Measure the area of ​​the updated three-dimensional mesh region to be measured to obtain the area of ​​the updated three-dimensional mesh region to be measured.

[0076] Specifically, as shown in Figure 6, when the user makes a mistake or is dissatisfied with the measurement results, the target 3D control point B is dragged to position B'. The 3D edge line is redrawn in real time. When the drag is released, a new updated 3D closed edge line and an updated 3D mesh area to be measured are generated, and the area of ​​the updated 3D mesh area to be measured is recalculated.

[0077] In an optional embodiment of this application, the method further includes the following steps:

[0078] (1) Based on the user's operation of adding a new three-dimensional control point on the three-dimensional closed edge line, determine the two endpoints of the three-dimensional edge line that are closest to the new three-dimensional control point, and calculate the closest point of the line segment formed by the new three-dimensional control point and the two endpoints;

[0079] (2) Determine whether the length from the new 3D control point to the nearest point is less than the preset line segment width;

[0080] (3) If it is less than, then determine the projection of the new 3D control point onto the nearest 3D edge line, and complete the operation of adding the new 3D control point on the nearest 3D edge line.

[0081] Specifically, for greater flexibility in interaction, this application allows for the manual addition of new 3D control points along the edge lines to achieve a more accurate area envelope.

[0082] As shown in Figure 7, since the 3D closed edge line is composed of multiple 3D edge lines, the distance from the mouse position P (i.e., the new 3D control point) to the two endpoints BC of the nearest 3D edge line is calculated. Then, the nearest point Q of the line segment BC formed by the new 3D control point and these two endpoints is found. It is then determined whether the length of PQ is less than the preset line segment width. Based on this, it is determined whether the new 3D control point has been projected onto the nearest 2D edge line and its corresponding 3D coordinates Q. After adding a new 3D control point, it can also be dragged, and the edge line updates in real time based on the positions of all 3D control points.

[0083] In an optional embodiment of this application, the method further includes the following steps:

[0084] (1) Delete the target 3D control points based on the user's deletion operation on the target 3D closed edge line;

[0085] (2) Update the three-dimensional closed edge line based on the remaining three-dimensional control points on the three-dimensional closed edge line;

[0086] (3) Determine the updated three-dimensional mesh region of the face model to be measured, which is surrounded by the updated three-dimensional closed edge line;

[0087] (4) Measure the area of ​​the updated three-dimensional mesh region to be measured to obtain the area of ​​the updated three-dimensional mesh region to be measured.

[0088] Specifically, after deleting the target 3D control points, the 3D edge lines will also be updated in real time based on all the remaining 3D control points. Finally, when the mouse is released, the updated 3D closed edge lines are obtained. The updated 3D mesh region to be measured, which is surrounded by the updated 3D closed edge lines (i.e., the model triangular mesh is accurately subdivided using the updated 3D closed edge lines), is then calculated, and the area of ​​the updated 3D mesh region to be measured is obtained.

[0089] The method for measuring the area of ​​a 3D face model in this application enables accurate and effective measurement of the surface area on the 3D face model in a visual manner, and allows for real-time adjustment of the measurement position. It also effectively solves the problems of measuring complex surfaces, measuring intersecting edge lines, and measuring geometric edges and holes.

[0090] Key points of this application include:

[0091] 1. A surface area measurement method that involves adding control points one by one to close the edge line;

[0092] 2. First, use the edge lines to coarsely divide the inner and outer triangular meshes, and then finely divide the triangular meshes that the edge lines pass through;

[0093] 3. Drag, add, or delete control points to create new closed regions.

[0094] This application has the following advantages:

[0095] 1. The surface area of ​​a 3D model can be measured by adding control points to close the edge lines. The operation is simple and the visualization is intuitive.

[0096] 2. Automatic edge smoothing optimizes user experience. Triangular meshes are cut using a coarse-to-fine subdivision method, resulting in accurate and reliable area results.

[0097] 3. Control points can be dragged, added, and deleted, allowing users to adjust measurement results according to actual needs.

[0098] Example 2:

[0099] This application also provides an area measurement device for a three-dimensional face model. This three-dimensional face model area measurement device is mainly configured to execute the area measurement method for a three-dimensional face model provided in Embodiment 1 of this application. The following is a detailed description of the area measurement device for a three-dimensional face model provided in this application.

[0100] Figure 8 is a schematic diagram of an area measurement device for a 3D face model according to an embodiment of this application. As shown in Figure 8, the device mainly includes: a first generation unit 10, a second generation unit 20, a determination unit 30, and an area measurement unit 40, wherein:

[0101] The first generation unit is configured to load and display the 3D model of the face to be tested in the planar display area, and generate ordered 3D control points based on the user's point selection operation on the 3D model of the face to be tested, and display them on the display plane. The order of the 3D control points is related to the order of the user's point selection operation. The 3D control point is a ray that extends from the point selection operation position displayed on the display plane, is perpendicular to the display plane and points to the 3D model of the face to be tested, and is the first intersection point of the ray with the 3D model of the face to be tested.

[0102] The second generation unit is configured to generate a three-dimensional closed edge line based on multiple ordered three-dimensional control points;

[0103] The unit is configured to determine the three-dimensional mesh region of the three-dimensional face model to be measured, which is surrounded by the three-dimensional closed edge line, based on the three-dimensional closed edge line.

[0104] The area measurement unit is configured to measure the area of ​​the three-dimensional mesh region to be measured, thereby obtaining the area of ​​the three-dimensional mesh region to be measured.

[0105] In this embodiment, a device for measuring the area of ​​a 3D face model is provided, comprising: loading and displaying a 3D face model to be measured in a planar display area; generating ordered 3D control points based on user point selection operations on the 3D face model to be measured, and displaying them on the display plane, wherein the order of the 3D control points is related to the order of user point selection operations, and the 3D control points are rays extending from the point selection operation positions displayed on the display plane, perpendicular to the display plane and pointing to the 3D face model to be measured, and the first intersection point of the ray with the 3D face model to be measured; generating 3D closed edge lines based on multiple ordered 3D control points; determining the 3D mesh region to be measured of the 3D face model to be measured enclosed by the 3D closed edge lines; and measuring the area of ​​the 3D mesh region to be measured to obtain the area of ​​the 3D mesh region to be measured. As described above, in the face 3D model area measurement device of this application, the user can perform point selection operations on the face 3D model to be measured, thereby obtaining ordered 3D control points. Then, based on multiple ordered 3D control points, a 3D closed edge line is generated. Finally, the area of ​​the 3D mesh region of the face 3D model to be measured, which is surrounded by the 3D closed edge line, is measured. That is, the surface area of ​​the face 3D model is measured by adding control points and closed edge lines. The operation is simple and visual. The determined 3D mesh region to be measured is continuous. Moreover, the method of automatically generating 3D control points through point selection is highly accurate. The final obtained 3D closed edge line and the 3D mesh region to be measured surrounded by the 3D closed edge line are more accurate. This alleviates the technical problems of traditional 3D model area measurement methods, such as complicated operation when selecting the region to be measured, lack of continuity of the selected region to be measured, and poor accuracy when using brush operations.

[0106] Optionally, the second generation unit is further configured to: generate the current 3D edge line between the current 3D control point and the previous 3D control point using spline curves, and optimize all generated 3D edge lines according to the current 3D control point to make the 3D edge lines on both sides of each 3D control point transition smoothly until the current 3D control point is the starting 3D control point, thus obtaining a 3D closed edge line.

[0107] Optionally, the second generation unit is further configured to: generate the current 3D edge line between the current 3D control point and the previous 3D control point using spline curves, and optimize the previous 3D edge line according to the current 3D control point so that the 3D edge lines on both sides of the current 3D control point are smoothly transitioned until the current 3D control point is the starting 3D control point, thus obtaining a 3D closed edge line.

[0108] Optionally, the second generation unit is further configured to: if the distance between the current 3D control point and the previous 3D control point is greater than a preset distance threshold, generate an additional 3D control point between the current 3D control point and the previous 3D control point; and generate the current 3D edge line between the previous 3D control point, the additional 3D control point and the current 3D control point using a spline curve.

[0109] Optionally, the determining unit is further configured to: determine the extreme point of the three-dimensional edge line in the first target direction based on the three-dimensional closed edge line, wherein the first target direction is arbitrary; traverse the three-dimensional closed edge line along the second target direction starting from the extreme point of the three-dimensional edge line, and when a fork occurs, traverse along the outer three-dimensional edge line until returning to the extreme point of the three-dimensional edge line, thereby obtaining the maximum region enclosed by the three-dimensional closed edge line, wherein the second target direction includes any of the following directions: clockwise direction and counterclockwise direction; and take the maximum region enclosed by the three-dimensional closed edge line as the three-dimensional mesh region to be measured of the three-dimensional face model to be measured enclosed by the three-dimensional closed edge line.

[0110] Optionally, the area measurement unit is further configured to: if the first target triangle in the three-dimensional mesh region to be measured is not divided by a three-dimensional closed edge line, calculate the area of ​​the first target triangle based on the three-dimensional coordinates of its vertices; if the second target triangle in the three-dimensional mesh region to be measured is divided by a three-dimensional closed edge line, subdivide the second target triangle into second target sub-triangles using the three-dimensional edge line used for division as the dividing line, and calculate the area of ​​the second target sub-triangle based on the three-dimensional coordinates of its vertices, wherein the second target sub-triangle is a triangle located within the three-dimensional mesh region to be measured; and calculate the area of ​​the three-dimensional mesh region to be measured based on the area of ​​the first target triangle and the area of ​​the second target sub-triangle.

[0111] Optionally, the device is further configured to: adjust the position of the target 3D control point based on the user's dragging operation on the target 3D control point on the 3D closed edge line; update the 3D closed edge line based on the adjusted position of the target 3D control point; determine the updated 3D mesh region of the face model to be measured enclosed by the updated 3D closed edge line based on the updated 3D closed edge line; and measure the area of ​​the updated 3D mesh region to be measured to obtain the area of ​​the updated 3D mesh region to be measured.

[0112] Optionally, the device is further configured to: determine the two endpoints of the three-dimensional edge line closest to the new three-dimensional control point based on the user's operation of adding a new three-dimensional control point on the three-dimensional closed edge line, and calculate the nearest point of the line segment formed by the new three-dimensional control point and the two endpoints; determine whether the length from the new three-dimensional control point to the nearest point is less than the preset line segment width; if it is less, determine that the new three-dimensional control point is projected onto the nearest three-dimensional edge line, and complete the operation of adding a new three-dimensional control point on the nearest three-dimensional edge line.

[0113] Optionally, the device is further configured to: delete the target 3D control points based on the user's deletion operation on the target 3D control points on the 3D closed edge line; update the 3D closed edge line based on the remaining 3D control points on the 3D closed edge line; determine the updated 3D mesh region of the face model to be measured enclosed by the updated 3D closed edge line based on the updated 3D closed edge line; and perform area measurement on the updated 3D mesh region to obtain the area of ​​the updated 3D mesh region to be measured.

[0114] The device provided in this application embodiment has the same implementation principle and technical effect as the aforementioned method embodiment. For the sake of brevity, any parts not mentioned in the device embodiment can be referred to the corresponding content in the aforementioned method embodiment.

[0115] As shown in Figure 9, an electronic device 600 provided in this application embodiment includes: a processor 601, a memory 602 and a bus. The memory 602 stores machine-readable instructions that can be executed by the processor 601. When the electronic device is running, the processor 601 and the memory 602 communicate through the bus. The processor 601 executes the machine-readable instructions to perform the steps of the above-described method for measuring the area of ​​a three-dimensional face model.

[0116] Specifically, the memory 602 and processor 601 mentioned above can be general-purpose memory and processor, without any specific limitations. When the processor 601 runs the computer program stored in the memory 602, it can execute the above-mentioned method for measuring the area of ​​the three-dimensional face model.

[0117] Processor 601 may be an integrated circuit chip with signal processing capabilities. In implementation, each step of the above method can be completed by the integrated logic circuitry in the hardware of processor 601 or by instructions in software form. The processor 601 can be a general-purpose processor, including a Central Processing Unit (CPU), a Network Processor (NP), etc.; it can also be a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field-Programmable Gate Array (FPGA), or other programmable logic devices, discrete gate or transistor logic devices, or discrete hardware components. It can implement or execute the methods, steps, and logic block diagrams disclosed in the embodiments of this application. The general-purpose processor can be a microprocessor or any conventional processor. The steps of the methods disclosed in the embodiments of this application can be directly manifested as execution by a hardware decoding processor, or execution by a combination of hardware and software modules in the decoding processor. The software module can reside in a mature storage medium in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory 602, and processor 601 reads the information from memory 602 and, in conjunction with its hardware, completes the steps of the above method.

[0118] Corresponding to the above-described method for measuring the area of ​​a 3D face model, this application also provides a computer-readable storage medium storing machine-executable instructions. When the machine-executable instructions are called and run by a processor, the machine-executable instructions cause the processor to perform the steps of the above-described method for measuring the area of ​​a 3D face model.

[0119] The face 3D model area measurement device provided in this application embodiment can be specific hardware on a device or software or firmware installed on the device. The device provided in this application embodiment has the same implementation principle and technical effects as the aforementioned method embodiment. For the sake of brevity, any parts not mentioned in the device embodiment can be referred to the corresponding content in the aforementioned method embodiment. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can all be referred to the corresponding processes in the above method embodiments, and will not be repeated here.

[0120] In the embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. The apparatus embodiments described above are merely illustrative. For example, the division of units is only a logical functional division, and there may be other division methods in actual implementation. Furthermore, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Additionally, the coupling or direct coupling or communication connection shown or discussed may be through some communication interface; the indirect coupling or communication connection between apparatuses or units may be electrical, mechanical, or other forms.

[0121] For example, the flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of apparatus, methods, and computer program products according to various embodiments of this application. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing the specified logical function. It should also be noted that in some alternative implementations, the functions marked in the blocks may occur in a different order than those marked in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. It should also be noted that each block in a block diagram and / or flowchart, and combinations of blocks in block diagrams and / or flowcharts, may be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

[0122] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0123] In addition, the functional units in the embodiments provided in this application can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit.

[0124] If the aforementioned functions are implemented as software functional units and sold or used as independent products, they can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of this application, or a part thereof, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause an electronic device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the face 3D model area measurement method of various embodiments of this application. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, portable hard drives, read-only memory (ROM), random access memory (RAM), magnetic disks, or optical disks.

[0125] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. In addition, the terms "first", "second", "third", etc. are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0126] Finally, it should be noted that the above-described embodiments are merely specific implementations of this application, used to illustrate the technical solutions of this application, and not to limit them. The protection scope of this application is not limited thereto. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can still modify or easily conceive of changes to the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features, within the scope of the technology disclosed in this application; and these modifications, changes, or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application. All should be covered within the protection scope of this application. Therefore, the protection scope of this application should be determined by the protection scope of the claims. Industrial applicability

[0127] In this embodiment, a method for measuring the area of ​​a 3D face model is provided, comprising: loading and displaying a 3D face model to be measured in a planar display area; generating ordered 3D control points based on user point selection operations on the 3D face model to be measured, and displaying them on the display plane; wherein the order of the 3D control points is related to the order of user point selection operations; the 3D control points are rays extending from the point selection operation positions displayed on the display plane, perpendicular to the display plane and pointing to the 3D face model to be measured, and the first intersection point of the ray with the 3D face model to be measured; generating 3D closed edge lines based on multiple ordered 3D control points; determining the 3D mesh region to be measured of the 3D face model to be measured enclosed by the 3D closed edge lines; and measuring the area of ​​the 3D mesh region to be measured to obtain the area of ​​the 3D mesh region to be measured. As described above, in the method for measuring the area of ​​a 3D face model in this application, the user can perform point selection operations on the 3D face model to be measured, thereby obtaining ordered 3D control points. Then, based on multiple ordered 3D control points, a 3D closed edge line is generated. Finally, the area of ​​the 3D mesh region of the 3D face model to be measured, which is surrounded by the 3D closed edge line, is measured. That is, the surface area of ​​the 3D face model is measured by adding control points and closing the edge line. The operation is simple and visual. The determined 3D mesh region to be measured is continuous. Moreover, the method of automatically generating 3D control points through point selection is highly accurate. The final obtained 3D closed edge line and the 3D mesh region to be measured surrounded by the 3D closed edge line are more accurate. This alleviates the technical problems of traditional 3D model area measurement methods, such as complex operation when selecting the region to be measured, lack of continuity of the selected region to be measured, and poor accuracy when using brush operations.

Claims

1. A method for measuring the area of ​​a 3D face model, comprising: A 3D model of the face to be tested is loaded and displayed in the planar display area. Ordered 3D control points are generated based on the user's point selection operation on the 3D model of the face to be tested, and displayed on the display plane. The order of the 3D control points is related to the order of the user's point selection operation. The 3D control point is a ray that is perpendicular to the display plane and points to the 3D model of the face to be tested from the point selection operation position displayed on the display plane. The first intersection point of the ray with the 3D model of the face to be tested is the first point of intersection of the ray with the 3D model of the face to be tested. A three-dimensional closed edge line is generated based on multiple ordered three-dimensional control points; The three-dimensional mesh region to be measured of the three-dimensional face model under test, enclosed by the three-dimensional closed edge line, is determined based on the three-dimensional closed edge line. The area of ​​the three-dimensional mesh region to be measured is obtained by measuring the area of ​​the three-dimensional mesh region to be measured.

2. The method according to claim 1, wherein, Generating a three-dimensional closed edge line based on multiple ordered three-dimensional control points, including: The current 3D edge line is generated between the current 3D control point and the previous 3D control point using spline curves. All generated 3D edge lines are then optimized based on the current 3D control point to make the transition of the 3D edge lines on both sides of each 3D control point smooth, until the current 3D control point becomes the starting 3D control point, thus obtaining the 3D closed edge line.

3. The method according to claim 1, wherein, Generating a three-dimensional closed edge line based on multiple ordered three-dimensional control points, including: The current 3D edge line is generated between the current 3D control point and the previous 3D control point using spline curves. The previous 3D edge line is then optimized based on the current 3D control point to make the 3D edge lines on both sides of the current 3D control point transition smoothly until the current 3D control point becomes the starting 3D control point, thus obtaining the 3D closed edge line.

4. The method according to claim 3, wherein, The current 3D edge line is generated between the current 3D control point and the previous 3D control point using spline curves, including: If the distance between the current 3D control point and the previous 3D control point is greater than a preset distance threshold, then an additional 3D control point is generated between the current 3D control point and the previous 3D control point. The current 3D edge line is generated between the previous 3D control point, the additional 3D control point, and the current 3D control point using the spline curve method.

5. The method according to any one of claims 1 to 4, wherein, The three-dimensional mesh region to be measured of the three-dimensional face model enclosed by the three-dimensional closed edge line is determined based on the three-dimensional closed edge line, including: The extreme point of the three-dimensional edge line in the first target direction is determined based on the three-dimensional closed edge line, wherein the first target direction is any direction; Starting from the extreme point of the three-dimensional edge line, traverse the three-dimensional closed edge line along the second target direction, and when a fork occurs, traverse along the outer three-dimensional edge line until returning to the extreme point of the three-dimensional edge line, to obtain the maximum area enclosed by the three-dimensional closed edge line. The second target direction includes any of the following directions: clockwise direction and counterclockwise direction. The largest region enclosed by the three-dimensional closed edge line is taken as the three-dimensional mesh region to be measured of the three-dimensional face model to be measured, which is enclosed by the three-dimensional closed edge line.

6. The method according to any one of claims 1 to 5, wherein, The area measurement of the three-dimensional mesh region to be measured includes: If the first target triangle in the three-dimensional mesh region to be measured is not divided by the three-dimensional closed edge line, then the area of ​​the first target triangle is calculated based on the three-dimensional coordinates of the vertices of the first target triangle; If the second target triangle in the three-dimensional mesh region to be measured is divided by the three-dimensional closed edge line, the second target triangle is subdivided into second target sub-triangles using the three-dimensional edge line used for division as the dividing line, and the area of ​​the second target sub-triangle is calculated based on the three-dimensional coordinates of the vertices of the second target sub-triangle, wherein the second target sub-triangle is a triangle located in the three-dimensional mesh region to be measured; The area of ​​the three-dimensional mesh region to be measured is calculated based on the area of ​​the first target triangle and the area of ​​the second target sub-triangle.

7. The method according to any one of claims 1 to 6, further comprising: The position of the target 3D control point is adjusted according to the user's dragging operation on the target 3D control point on the 3D closed edge line; Update the 3D closed edge line based on the adjusted position of the target 3D control points; The updated three-dimensional mesh region of the three-dimensional face model under test, enclosed by the updated three-dimensional closed edge line, is determined based on the updated three-dimensional closed edge line. The area of ​​the updated three-dimensional mesh region to be measured is obtained by measuring the area of ​​the updated three-dimensional mesh region to be measured.

8. The method according to any one of claims 1 to 7, further comprising: Based on the user's operation of adding a new 3D control point on the 3D closed edge line, determine the two endpoints of the 3D edge line closest to the new 3D control point, and calculate the nearest point of the line segment formed by the new 3D control point and the two endpoints; Determine whether the length from the new 3D control point to the nearest point is less than the preset line segment width; If it is less than, then the new 3D control point is determined to be projected onto the nearest 3D edge line, and the operation of adding the new 3D control point on the nearest 3D edge line is completed.

9. The method according to any one of claims 1 to 8, further comprising: The target 3D control point is deleted based on the user's deletion operation on the target 3D control point on the 3D closed edge line; Update the three-dimensional closed edge line based on the remaining three-dimensional control points on the three-dimensional closed edge line; The updated three-dimensional mesh region of the three-dimensional face model under test, enclosed by the updated three-dimensional closed edge line, is determined based on the updated three-dimensional closed edge line. The area of ​​the updated three-dimensional mesh region to be measured is obtained by measuring the area of ​​the updated three-dimensional mesh region to be measured.

10. An area measurement device for a three-dimensional face model, comprising: The first generation unit is configured to load and display a 3D model of the face to be tested in a planar display area, and generate ordered 3D control points based on the user's point selection operation on the 3D model of the face to be tested, and display them on the display plane. The order of the 3D control points is related to the order of the user's point selection operation. The 3D control point is a ray that extends from the point selection operation position displayed on the display plane, is perpendicular to the display plane and points to the 3D model of the face to be tested, and the first intersection point of the ray with the 3D model of the face to be tested. The second generation unit is configured to generate a three-dimensional closed edge line based on a plurality of ordered three-dimensional control points; The determining unit is configured to determine the three-dimensional mesh region to be measured of the three-dimensional face model surrounded by the three-dimensional closed edge line based on the three-dimensional closed edge line; An area measurement unit is configured to measure the area of ​​the three-dimensional grid region to be measured, thereby obtaining the area of ​​the three-dimensional grid region to be measured.

11. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the steps of the method according to any one of claims 1 to 9.

12. A computer-readable storage medium storing machine-executable instructions that, when invoked and executed by a processor, cause the processor to perform the method of any one of claims 1 to 9.

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