Annular cutting method of three-dimensional clothing sleeve model based on near-cylinder mapping

Abstract

The invention discloses an annular cutting method of a three-dimensional clothing sleeve model based on near-cylinder mapping, which can perform annular cutting on sleeves in a clothing three-dimensional model acquired by three-dimensional scanning to obtain a series of annular cutting lines. Comprising the following steps: (1) preprocessing a sleeve three-dimensional mesh model; (2) rotating, translating and zooming the sleeve three-dimensional mesh model; (3) detecting the boundary of the sleeve three-dimensional mesh model; (4) plane mapping of boundaries of the sleeve three-dimensional grid model; (5) carrying out tensile deformation on the sleeve three-dimensional mesh model; (6) setting a three-dimensional cutting plane; and (7) cutting the stretched sleeve three-dimensional mesh model by using a three-dimensional cutting plane, and repeatedly using the weight of the sleeve three-dimensional mesh model.

Description

Technical Field

[0001] This invention belongs to the field of clothing sleeve design, and specifically relates to a method for ring cutting of a three-dimensional clothing sleeve model based on near-cylindrical mapping. Background Technology

[0002] With the accelerated digital transformation of the apparel industry, 3D apparel modeling technology has become a core link connecting design, production, and customization. Among these technologies, 3D scanning technology is widely used for 3D model reconstruction of apparel due to its ability to quickly acquire data on the true shape of clothing. As a key functional and styling component of clothing, the accurate processing of the 3D model of the sleeve directly determines the efficiency and accuracy of reverse engineering. Currently, when performing structural decomposition and feature extraction on scanned 3D apparel models, the circular data segmentation of the sleeve model remains a technical challenge. Traditional cutting methods often rely on manual marking or simple geometric feature division, requiring designers to have extensive experience. Furthermore, the cutting lines are prone to offset and discontinuity, making it difficult to adapt to the complex curved surface of the near-cylindrical shape of the sleeve. This leads to the accumulation of data errors in subsequent reverse engineering steps such as mesh flattening and pattern generation, affecting the fit of the garment. Existing technologies lack a dedicated circular cutting scheme for sleeve models, making it impossible to efficiently generate uniform and accurate circular cutting lines, thus hindering the automation and standardization of reverse engineering of 3D apparel models. Summary of the Invention

[0003] The purpose of this invention is to provide a circular cutting method for a three-dimensional garment sleeve model based on near-cylindrical mapping. In view of the deficiencies in the prior art, the sleeve in the three-dimensional garment model acquired by three-dimensional scanning is cut in a circular manner to obtain a series of circular cutting lines.

[0004] To solve the above-mentioned technical problems, the following technical solution is adopted.

[0005] A method for circular cutting of a 3D garment sleeve model based on near-cylindrical mapping includes the following steps.

[0006] (1) Preprocessing of the sleeve 3D mesh model to make the area distribution of all triangles in the sleeve 3D mesh model uniform.

[0007] (2) The sleeve 3D mesh model is rotated, translated and scaled to adjust to the orientation or trend required by the design.

[0008] (3) Boundary detection of the sleeve three-dimensional mesh model.

[0009] (4) Planar mapping of the boundary of the sleeve 3D mesh model.

[0010] (5) Stretching deformation of the three-dimensional mesh model of the sleeve.

[0011] (6) Setting the three-dimensional cutting plane.

[0012] (7) The three-dimensional cutting plane cuts and reuses the weights of the stretched sleeve three-dimensional mesh model.

[0013] After optimization, step (2) includes:

[0014] a. Rotate the 3D mesh model of the sleeve so that the main body of the sleeve is distributed along the Z-axis of the XYZ coordinate system, with the cuff located above the XY plane and the heel located below the XY plane.

[0015] b. Translate the 3D mesh model of the sleeve so that its centroid is at the origin of the XYZ coordinate axis.

[0016] c. Scale the sleeve 3D mesh model to the unit sphere.

[0017] After optimization, in step (3), the three-dimensional vertices belonging to the boundary points in the three-dimensional mesh model of the sleeve are selected and marked as the cuff boundary point and the sleeve root boundary point according to their position on the sleeve.

[0018] After optimization, in step (4), the selected cuff boundary points are mapped to a three-dimensional space plane PL1, which is perpendicular to the Z-axis of the XYZ coordinate axis; the selected cuff boundary points are mapped to a three-dimensional space plane PL2, which is perpendicular to the Z-axis of the XYZ coordinate axis, and PL1 and PL2 are parallel.

[0019] After optimization, in step (5), the mapped cuff boundary point coordinates and the mapped sleeve root boundary point coordinates are used as part of the new coordinates of the sleeve three-dimensional mesh model. The new coordinates are used as constraint points, and the new coordinates of the remaining vertices are solved using the Laplace mesh deformation method or the Poisson deformation method. After stretching, the cuff boundary and sleeve root boundary of the sleeve three-dimensional mesh model are on parallel three-dimensional planes, and the sleeve three-dimensional model is approximately cylindrical.

[0020] After optimization, the three-dimensional mesh model of the sleeve after stretching and deformation is not a true cylindrical mapping result, but is essentially a three-dimensional mesh model of the sleeve that approximates a cylinder.

[0021] After optimization, in step (6), a series of cutting planes perpendicular to the Z coordinate axis are set. The Z value of the series of cutting planes ranges from -2 to 2. The height difference of the Z value of adjacent cutting planes can be set according to the actual situation. If a large number of cutting lines are required, the height difference is reduced; if a small number of cutting lines are required, the height difference is increased.

[0022] After optimization, in step (7), the cutting planes are traversed to find all intersection points between the mapped sleeve 3D mesh model and each cutting plane. The intersection point refers to the intersection point of the triangle side in the sleeve 3D mesh model and the cutting plane. The weight coefficient of the intersection point is calculated. The weight coefficient refers to the coefficient of the intersection point on its intersecting edge. Since the topology of the sleeve model remains unchanged before and after stretching, the calculated weight coefficient is applied to the triangle side of the sleeve 3D mesh model before deformation to find an intersection point of the sleeve 3D mesh model before stretching and deformation. The result is recorded as a cutting result.

[0023] After optimization, the weight coefficients of the intersection points are calculated, including the intersection points. On the side of the triangle superior, The two endpoints are and ,satisfy , Intersection On the side of the triangle The weighting coefficients.

[0024] After optimization, the intersection points of the 3D mesh model of the sleeve before stretching deformation are calculated. Triangle edges applied to the undeformed 3D mesh model of the sleeve Using the formula Find the intersection points of the 3D mesh model of the sleeve before stretching and deformation.

[0025] The above technical solution has the following beneficial effects.

[0026] The method proposed in this invention can cut a three-dimensional triangular sleeve model in a straight or bent state into a series of ring-shaped cutting lines, which can provide technical support for the reverse design of clothing three-dimensional models.

[0027] This invention can cut a three-dimensional mesh model of a sleeve in a bent or straight state using a circular cutting method.

[0028] This method is highly flexible and can adjust the density of the final cutting result according to the actual situation.

[0029] This method is not limited to circular cutting of the sleeve's three-dimensional mesh model; it can also be used to achieve vertical cutting of the sleeve model according to the method of this invention.

[0030] The key technology of this invention lies in the mapping of two sets of boundaries of the sleeve three-dimensional model to two planes and the stretching deformation of the sleeve three-dimensional mesh model. This set of algorithms can stretch the originally curved sleeve three-dimensional mesh model into an approximately cylindrical three-dimensional model, so that parallel three-dimensional planes can cut it. Attached Figure Description

[0031] The invention will now be further described with reference to the accompanying drawings.

[0032] Figure 1 A flowchart of a method for circular cutting of a 3D garment sleeve model based on near-cylindrical mapping.

[0033] Figure 2 Example of the boundary vertices of a 3D mesh model of a sleeve.

[0034] Figure 3 Example of 3D boundary mapping and mesh stretching deformation results for a sleeve 3D mesh model.

[0035] Figure 4 Examples of 3D mesh models of sleeves after stretching and deformation, and cutting planes with different settings.

[0036] Figure 5 Example image of cutting a 3D mesh model of a sleeve. Detailed Implementation

[0037] The present invention aims to provide a method for circular cutting of a three-dimensional garment sleeve model based on near-cylindrical mapping, which involves circularly cutting the sleeve of a three-dimensional garment model acquired by three-dimensional scanning to obtain a series of circular cutting lines.

[0038] The present invention will be further described below with reference to specific embodiments.

[0039] A method for circular cutting of a 3D garment sleeve model based on near-cylindrical mapping includes the following steps.

[0040] (1) Preprocessing of the three-dimensional mesh model of the sleeve.

[0041] Preprocessing ensures that all triangles in the sleeve's 3D mesh model have a uniform area distribution, meaning that the areas of all triangle elements are similar. Figure 1 The 3D mesh model of the sleeve shown refers to a sleeve without buttons or seams at the cuff. This 3D mesh model of the sleeve can be in a straight state or a bent state.

[0042] (2) The sleeve three-dimensional mesh model is rotated, translated and scaled to adjust to the orientation or trend required by the design, specifically including.

[0043] a. Rotate the 3D mesh model of the sleeve so that the main body of the sleeve is distributed along the Z-axis of the XYZ coordinate system, with the cuff located above the XY plane and the heel located below the XY plane.

[0044] b. Translate the 3D mesh model of the sleeve so that its centroid is at the origin of the XYZ coordinate axis.

[0045] c. Scale the sleeve 3D mesh model to the unit sphere.

[0046] (3) Boundary detection of the sleeve three-dimensional mesh model.

[0047] Filter the 3D vertices that are boundary points in the 3D mesh model of the sleeve, and mark them as cuff boundary points and sleeve root boundary points according to their positions on the sleeve; for example Figure 2 The red curves shown represent the cuff and sleeve root boundaries.

[0048] (4) Planar mapping of the boundary of the sleeve 3D mesh model.

[0049] The selected cuff boundary points are mapped to a three-dimensional space plane PL1, which is perpendicular to the Z-axis of the XYZ coordinate system; the selected cuff boundary points are also mapped to a three-dimensional space plane PL2, which is perpendicular to the Z-axis of the XYZ coordinate system. PL1 and PL2 are parallel.

[0050] Map the cuff boundary B1 onto a two-dimensional circle with center (0, 0, 2) and normal vector (0, 0, 1); map the sleeve root boundary B2 onto a two-dimensional circle with center (0, 0, -2) and normal vector (0, 0, -1).

[0051] (5) Stretching deformation of the three-dimensional mesh model of the sleeve.

[0052] Map the cuff boundary B 1F and the mapped sleeve root boundary B 2F Using the known three-dimensional vertex, the sleeve three-dimensional mesh model is subjected to Poisson deformation or Laplace deformation. After stretching, the cuff boundary and the hem boundary of the sleeve model are on parallel three-dimensional planes. The sleeve three-dimensional model is approximately cylindrical. The stretched and deformed sleeve three-dimensional mesh model is not a true cylindrical mapping result, but is essentially an approximately cylindrical sleeve three-dimensional mesh model.

[0053] The 3D mesh model of the stretched and deformed sleeve is as follows: Figure 3 As shown, the upper boundary of the stretched and deformed sleeve model is located on the plane Z=2, and the lower boundary is located on the plane Z=-2. Here, Z=-2 and Z=2 can be adjusted according to the actual situation.

[0054] (6) Setting the three-dimensional cutting plane.

[0055] Different 3D planes are used to cut the stretched sleeve model. In this invention, the cutting plane is set perpendicular to the Z-axis, and the height (i.e., Z-value) of the cutting plane ranges from [-2, 2]. The step size is determined according to the actual situation. If a large number of cutting lines are required, the height difference is reduced; if a small number of cutting lines are required, the height difference is increased. The higher the number of cutting planes, the more accurately the cutting lines can represent the 3D mesh model of the sleeve. The cutting plane is not limited to a plane perpendicular to the Z-axis; it can also be set as a series of planes perpendicular to the XY-axis and passing through the Z-axis. This type of cutting plane can be used to cut along the length of the sleeve.

[0056] like Figure 4 As shown, setting the step size to 0.5 allows the use of 5 consecutive planar cut sleeve models; setting the step size to 0.2 allows the use of 21 consecutive planar cut sleeve models.

[0057] (7) The three-dimensional cutting plane cuts and reuses the weights of the stretched sleeve three-dimensional mesh model.

[0058] Traverse the cutting planes and find all intersection points between the mapped sleeve 3D mesh model and each cutting plane. An intersection point refers to the point where the sides of a triangle in the sleeve 3D mesh model intersect the cutting plane. Calculate the weight coefficient of each intersection point, which is the coefficient of the intersection point on its intersecting edges. For example, for a given intersection point... On the side of the triangle superior, The two endpoints are and ,satisfy , Intersection On the side of the triangle The weighting coefficients. Since the topology of the sleeve model remains unchanged before and after stretching, the weighting coefficients will be... Triangle edges applied to the undeformed 3D mesh model of the sleeve Using the formula Find the intersection points of the 3D mesh model of the sleeve before stretching and deformation, and record the result as the cutting result.

[0059] (8) Cutting results of the sleeve 3D model under different conditions.

[0060] like Figure 5 As shown, the method proposed in this invention can cut 3D sleeve models of different types and states. Regardless of whether the sleeve model is bent or straight, loose sleeves and wide-necked sleeves can be cut in a ring shape. Furthermore, cutting can also be achieved when the sleeve undergoes local deformation. Moreover, different cutting densities can be obtained based on the number of layers in the cutting plane.

[0061] The above are merely specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent substitutions, or modifications made based on the present invention to solve essentially the same technical problems and achieve essentially the same technical effects are all covered within the protection scope of the present invention.

Claims

1. A method for circular cutting of a 3D garment sleeve model based on near-cylindrical mapping, characterized in that... The process includes the following steps: (1) Preprocessing the sleeve 3D mesh model to make the area distribution of all triangles in the sleeve 3D mesh model uniform; (2) Rotating, translating and scaling the sleeve 3D mesh model to adjust it to the orientation or trend required by the design; (3) Boundary detection of the sleeve 3D mesh model; (4) Planar mapping of the boundary of the sleeve 3D mesh model; (5) Stretching deformation of the sleeve 3D mesh model; (6) Setting of the 3D cutting plane; (7) Cutting and weighting the stretched sleeve 3D mesh model with the 3D cutting plane.

2. The method for ring cutting of a three-dimensional garment sleeve model based on near-cylindrical mapping according to claim 1, characterized in that: Step (2) includes: a) rotating the sleeve 3D mesh model so that the main body of the sleeve is distributed along the Z-axis of the XYZ coordinate axis, with the cuff located above the XY plane and the heel located below the XY plane; b) translating the sleeve 3D mesh model so that its centroid is at the origin of the XYZ coordinate axis; c) scaling the sleeve 3D mesh model to the unit sphere.

3. The method for ring cutting of a three-dimensional garment sleeve model based on near-cylindrical mapping according to claim 1, characterized in that: In step (3), the three-dimensional vertices that belong to the boundary points in the three-dimensional mesh model of the sleeve are selected and marked as the cuff boundary point and the sleeve root boundary point according to their position on the sleeve.

4. The method for ring cutting of a three-dimensional garment sleeve model based on near-cylindrical mapping according to claim 3, characterized in that: In step (4), the selected cuff boundary points are mapped to a three-dimensional space plane PL1, which is perpendicular to the Z-axis of the XYZ coordinate system; the selected cuff boundary points are mapped to a three-dimensional space plane PL2, which is perpendicular to the Z-axis of the XYZ coordinate system, and PL1 and PL2 are parallel.

5. The method for ring cutting of a three-dimensional garment sleeve model based on near-cylindrical mapping according to claim 4, characterized in that: In step (5), the mapped cuff boundary point coordinates and the mapped sleeve root boundary point coordinates are used as part of the new coordinates of the sleeve three-dimensional mesh model. These new coordinates are used as constraint points. The new coordinates of the remaining vertices are solved using the Laplace mesh deformation method or the Poisson deformation method. After stretching, the cuff boundary and sleeve root boundary of the sleeve three-dimensional mesh model are on parallel three-dimensional planes, and the sleeve three-dimensional mesh model is approximately cylindrical.

6. The method for ring cutting of a three-dimensional garment sleeve model based on near-cylindrical mapping according to claim 5, characterized in that: The stretched and deformed 3D mesh model of the sleeve is not a true cylindrical mapping result; it is essentially a 3D mesh model of the sleeve that approximates a cylinder.

7. The method for ring cutting of a three-dimensional garment sleeve model based on near-cylindrical mapping according to claim 1, characterized in that: In step (6), a series of cutting planes perpendicular to the Z-axis are set. The Z-value of the series of cutting planes ranges from -2 to 2. The height difference of the Z-value of adjacent cutting planes can be set according to the actual situation. If a large number of cutting lines are required, the height difference is reduced; if a small number of cutting lines are required, the height difference is increased.

8. The method for ring cutting of a three-dimensional garment sleeve model based on near-cylindrical mapping according to claim 7, characterized in that: In step (7), traverse the cutting planes and find all intersection points between the mapped sleeve 3D mesh model and each cutting plane. The intersection point refers to the intersection point between the triangle side in the sleeve 3D mesh model and the cutting plane. Calculate the weight coefficient of the intersection point, which is the coefficient of the intersection point on its intersecting edge. Since the topology of the sleeve model remains unchanged before and after stretching, apply the calculated weight coefficient to the triangle edge of the sleeve 3D mesh model before deformation to find the intersection point of the sleeve 3D mesh model before stretching and deformation, and record the result as the cutting result.

9. A method for ring cutting of a three-dimensional garment sleeve model based on near-cylindrical mapping according to claim 8, characterized in that: Calculate the weight coefficient of the intersection point, including the intersection point. On the side of the triangle superior, The two endpoints are and ,satisfy , Intersection On the side of the triangle The weighting coefficients.

10. A method for circular cutting of a three-dimensional garment sleeve model based on near-cylindrical mapping according to claim 9, characterized in that: Calculate the intersection points of the 3D mesh model of the sleeve before stretching and deformation. Triangle edges applied to the undeformed 3D mesh model of the sleeve Using the formula Find the intersection points of the 3D mesh model of the sleeve before stretching and deformation.

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