Garment prototype template generation method based on feature point space mapping

Abstract

The invention discloses a feature point space mapping-based garment prototype template generation method, which comprises the following steps of: acquiring accurate three-dimensional point cloud data of a human body by using a [TC] 2 three-dimensional human body scanner to obtain 10 pieces of human body data related to a template making size; eight feature sections and twelve feature points of the upper body of the human body are defined. The Euclidean distance between two adjacent points is accumulated, the length of a characteristic section curve is approximately calculated, and MATLAB is used for carrying out quadratic polynomial fitting on curve parameters, so that the accuracy of the method is verified. Setting a two-dimensional plane, translating the coordinates of the points on the cross section in the projection direction or translating the mapping distance in the reverse direction to obtain the projection coordinates of the points, and realizing the mapping of the three-dimensional curve to the two-dimensional plane. And finally, carrying out structure correction by using reverse engineering software Geomagic control X 64. According to the technical scheme of the invention, the generation of the clothing prototype template based on feature point space mapping can be realized, the generation precision and production efficiency of the template are improved, and the purpose of production is achieved.

Description

Technical Field

[0001] The invention belongs to the field of clothing samples, and in particular relates to a method for generating clothing prototype samples based on feature point space mapping. The method combines three-dimensional human body scanning technology, reverse engineering modeling technology, quadratic polynomial fitting curve technology, mathematical and geometric principles to generate clothing prototype samples. Background Art

[0002] Clothing samples are a key link in clothing design and production. As the industry trend shifts from mass production to personalized customization, prototype samples, the foundation of all kinds of clothing design, have an increasingly significant impact on the industry. At present, the generation of prototype samples mainly adopts the following three methods: (1) three-dimensional cutting method; (2) prototype formula method; (3) computer-aided surface flattening technology. In actual operation, the three-dimensional cutting method is limited by the skills and experience of the craftsman and has a limited scope of application. In contrast, the prototype formula method is more common and is designed on a two-dimensional plane. However, this method requires designers to convert three-dimensional shapes into two-dimensional patterns, which often leads to repeated modifications and sample redoing, which wastes resources. The surface flattening method can improve accuracy, reduce costs, and adapt to rapidly changing market demands. It shows great potential in ensuring the fit and comfort of clothing and is one of the key breakthrough directions in the current field of computer modeling.

[0003] Among them, Patent No. CN108741346A solves the demand for personalized customization of clothing prototype samples, and converts the human body surface unfolding into sample curve parameter adjustment, but its model complexity and parameter adjustment accuracy directly affect the final sample quality, and the algorithm needs to be further optimized to ensure efficient and accurate sample generation; CN 108634459A combines 3D human body measurement data with NURBS surface fitting and three-dimensional surface flattening technology to achieve digital sample generation from three-dimensional to two-dimensional for women's tops, but there is still room for improvement in the complexity and precision control of NURBS surface fitting, and the detail retention and distortion balance during two-dimensional flattening; Patent No. CN102880741A discloses a method for generating prototype samples of clothing bodies based on personalized three-dimensional virtual mannequins. This method can realize three-dimensional virtual mannequin construction and precise surface processing, and integrates three-dimensional accuracy and two-dimensional CAD convenience, but continuous optimization is needed in three-dimensional data processing and surface flattening algorithms. Patent No. CN109685883A discloses a method for automatically generating high-precision clothing samples by collecting human feature points, generating feature part curves, matching clothing prototype samples, and applying a distance slack model. However, there is a problem of limited personalized adaptability of the samples. How to efficiently and accurately generate clothing prototype samples that meet different human characteristics has become a research hotspot. Summary of the invention

[0004] The purpose of the present invention is to provide a clothing prototype sample generation method based on feature point space mapping. This method mainly solves the limitations of personalized sample generation in the previous technology, the model complexity and the parameter adjustment accuracy problems, and obtains a more accurate and efficient clothing prototype automatic generation technology to meet the market demand for rapid personalized customization.

[0005] In order to solve the above technical problems, the following technical solutions are adopted:

[0006] A method for generating a clothing prototype sample based on feature point space mapping, characterized by comprising the following steps:

[0007] (1) Adopt [TC] 2 A 3D human body scanner obtains 3D point cloud data of the human body;

[0008] (2) Determine the characteristic cross-sections and characteristic points of the human body;

[0009] (3) Calculation of arc length of characteristic section: The arc length of characteristic section is approximately obtained by accumulating the Euclidean distance between adjacent characteristic points on the characteristic section;

[0010] (4) Feature point mapping: Set a two-dimensional projection plane. Each feature point on the feature section has a corresponding arc length value, which represents the distance between the feature point and the starting point of the feature section, i.e., the mapping distance. Determine the projection direction based on the arc length value of the feature point on the feature section. Shift the coordinates of the feature point on the feature section toward the projection direction or in the opposite direction by the mapping distance to obtain the projection coordinates of the feature point.

[0011] (5) Prototype template mapping generation: Set the fixed point of the projection plane. For each characteristic section, map the characteristic point coordinates to the specified plane by adding or subtracting the arc length of the characteristic section to achieve the planarization of the three-dimensional curve.

[0012] (6) Structural modification: The mapped coordinates are imported into Geomagic control X 64 software to visualize the prototype.

[0013] After optimization, the step (1) adopts [TC] 2 The 3D human body scanner obtains 3D human body point cloud data and saves them in .wrl and .obj formats respectively; the scanner accuracy is 0.1mm, the scanning speed is 550000 points / second, and the spatial point distance is 0.2mm-3mm.

[0014] After optimization, 10 human body data related to the plate making size are selected from the obtained human body three-dimensional point cloud data, namely net chest circumference, net waist circumference, neck root circumference, front chest height, front chest width, back length, back width, shoulder width (1 / 2), armhole depth, and small shoulder width.

[0015] After optimization, in the step (2), the characteristic cross-section includes 4 basic characteristic cross-sections and 4 auxiliary characteristic cross-sections, the 4 basic characteristic cross-sections include a neck root circumference cross-section, a shoulder circumference cross-section, a chest circumference line cross-section and a waist circumference line cross-section; the 4 auxiliary characteristic cross-sections include an upper chest circumference line cross-section, a neck-shoulder equal section, an upper chest circumference-chest circumference equal section, and a chest circumference-waist circumference equal section.

[0016] After optimization, in the step (2), the feature points include side neck points, front collar points, back neck points, shoulder end points, chest points, waist side seam feature points, front armpit points, armhole points, back armpit points, front center, back center feature points and waist dart feature points, totaling 12 feature points.

[0017] After optimization, in step (3), after obtaining the arc length of the characteristic section, MATLAB is used to fit the curve parameters with a quadratic polynomial, generate coordinate data of the fitting curve, draw images of the original point cloud and the fitting curve, and finally calculate the length of the fitting curve and output the result to verify the accuracy of the characteristic section arc length calculation method.

[0018] After optimization, in the step (4), a two-dimensional plane is selected as a projection plane, which is a plane perpendicular to the characteristic section or a plane tangent to the characteristic section; the three-dimensional coordinates (x, y, z) of the characteristic point on the characteristic section are regarded as vector p; the projection direction is determined according to the arc length value of the characteristic point on the characteristic section; if the projection plane is perpendicular to the characteristic section, the projection direction is the same as the normal vector of the characteristic section; if the projection plane is tangent to the characteristic section, the projection direction is obtained by calculating the normal vector of the tangent plane; the coordinates of the characteristic point on the characteristic section are translated in the projection direction or in the opposite direction, and the distance is the arc length value of the characteristic point to obtain the projection coordinates of the characteristic point.

[0019] After optimization, the projection coordinates of the feature points mapped onto the two-dimensional projection plane are used for visualization to obtain information about the feature cross-sectional shape and the distribution of the feature points.

[0020] After optimization, the step (6) is visualized, the neckline arc and the armhole arc are rounded, the horizontal lines are symmetrical, and the vertical lines are kept vertical.

[0021] The above technical solution has the following beneficial effects:

[0022] The present invention, on the basis of having solved the demand for personalized customization of clothing prototype samples, provides a prototype sample generation method based on human body surface morphology mapping, and simplifies the mapping model through feature point correspondence, feature arc length calculation and curve mapping between three-dimensional space and two-dimensional samples on the basis of existing three-dimensional data processing and surface flattening algorithms, so as to achieve the correspondence between human feature points, feature lines and two-dimensional samples on the prototype sample structure, effectively solving the problem of limited personalized adaptability of samples, and simultaneously reducing the difficulty of three-dimensional flattening, so as to efficiently and accurately generate clothing prototype samples that meet the characteristics of different human bodies. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The present invention will be further described below in conjunction with the accompanying drawings:

[0024] Figure 1 This is the prototype structure diagram of the eighth generation of Japan's new culture style;

[0025] Figure 2 It is a schematic diagram of a cross section of a human body;

[0026] Figure 3 This is a schematic diagram of the prototype;

[0027] Figure 4 It is a schematic diagram of the feature point-line correspondence relationship;

[0028] Figure 5 It is a schematic diagram of the characteristic section arc length approximation algorithm;

[0029] Figure 6 It is a schematic diagram of feature point mapping;

[0030] Figure 7 It is a schematic diagram of the three-dimensional curve mapping of the front piece;

[0031] Figure 8 It is a schematic diagram of the three-dimensional curve mapping of the rear piece;

[0032] Fig. 9 It is a schematic diagram of the rear-front piece sample;

[0033] Fig.10 Correction diagram for the sample structure;

[0034] Fig.11 This is the effect picture of virtual fitting. DETAILED DESCRIPTION

[0035] The technical solution of the present invention is described in detail below in conjunction with specific embodiments:

[0036] (1) Obtaining 3D point cloud data of the human body

[0037] The subject stands upright with his upper body clean, passing [TC] 2The 3D human body scanner measures the test subject and obtains the 3D human body point cloud data. The 3D human body point cloud data is saved in .wrl and .obj formats. The scanner accuracy is 0.1mm, the scanning speed is 550,000 points / second, and the spatial point distance is 0.2mm-3mm. The required plate making size (such as Figure 1 ), and selected 10 parameters including net chest circumference, net waist circumference, neck circumference, front chest height, front chest width, back length, back width, shoulder width (1 / 2), armhole depth, and small shoulder width from the obtained human body 3D point cloud data samples. The above measurement items are all net body dimensions of the human body. These parameters can basically characterize the morphology of each part of the prototype sample.

[0038] (2) Determine the characteristic cross-section of the human body

[0039] The corresponding relationship between the human body characteristic cross section and the prototype sample is as follows Figure 2 and Figure 3 As shown, the following is a detailed description of the selected basic feature section and auxiliary feature section:

[0040] Basic feature sections, including:

[0041] a) Neck root section: Corresponding to the neck circumference of the prototype sample, this section surrounds the root of the human neck and provides an accurate reference for the design of the prototype neckline, ensuring that the size and shape of the prototype neckline conforms to the neck contour of the wearer.

[0042] b) Shoulder section: Corresponding to the shoulder point position and small shoulder width length of the prototype sample, this characteristic section surrounds the shoulder and determines the design and width of the prototype shoulder so that it can fit the wearer's shoulder contour.

[0043] c) Bust line section: Corresponding to the chest point position, chest dart position, and chest line height of the prototype pattern, this characteristic section surrounds the fullest part of the chest and determines the design and fit of the prototype chest to ensure that the chest part of the prototype can fit the wearer's chest contour and provide a comfortable wearing experience.

[0044] d) Waistline section: Corresponding to the waist height and waist length of the prototype sample, this characteristic section surrounds the thinnest part of the waist and determines the design and fit of the prototype waist to ensure that the prototype can fit the waist curve of the wearer.

[0045] Auxiliary feature sections, including:

[0046] a) Neck-shoulder section: This characteristic section divides the neck and shoulder equally, which helps to determine the shoulder width and collar position of the prototype, ensuring that the shoulder design of the prototype is consistent with the wearer's shoulder proportions.

[0047] b) Upper bust line section: Corresponding to the front armpit point and armhole dart position of the prototype pattern, this characteristic section surrounds the upper chest and determines the fit and slimming effect of the prototype upper body part to ensure that the prototype's upper body design conforms to the wearer's body curve.

[0048] c) Upper Bust-Chest Bisection: This section divides the upper bust and chest into equal parts, which helps to adjust the fit and cut of the prototype upper body part to ensure that the design of the prototype upper body fits the wearer's body shape.

[0049] d) Chest-waist equal section: This section divides the chest and waist into equal parts, which helps to adjust the transition effect between the upper and lower body of the prototype and ensure that the connection between the upper and lower body parts of the prototype is natural and smooth.

[0050] (3) Determine the human body feature points

[0051] Prototype design usually needs to take into account the key parts of the human body to ensure the fit and aesthetics of the prototype. Therefore, the neck, shoulders, chest, and waist points are selected as mapping feature points, such as Figure 4 shown.

[0052] a) Neck circumference feature points: The side neck point corresponds to the peak point of the radius of the neck root circumference section, and the value point is P19; the front collar point corresponds to the front midpoint of the shoulder section, and the value point is P1; the back neck point corresponds to the back midpoint of the neck-shoulder equal section, and the value point is P37.

[0053] b) Shoulder width feature point: The shoulder end points on both sides of the shoulders are usually located at the junction of the shoulder and the arm, corresponding to the peak point of the shoulder cross-sectional radius, and the value point is P19.

[0054] c) Chest feature point: The chest is the fullest part of the upper body and is usually located on the horizontal line of the highest point of the breast. The highest point of the chest is usually P9.

[0055] d) Waist circumference feature point: the thinnest part of the abdomen, the side seam value point is P19.

[0056] e) Armhole feature points: The armhole extends from the front armpit point through the armhole point to the back armpit point and finally to the shoulder point. The front armpit point is P14, the armhole point is P19, and the back armpit point is P25.

[0057] f) Front center and back center feature points: the value points are P1 and P37.

[0058] g) Waist dart feature point: The waist dart position is on the same vertical line as the bust point, and the value point is P9.

[0059] (4) Calculation of arc length of characteristic section: The arc length of characteristic section is approximated by accumulating the Euclidean distance between adjacent characteristic points on the characteristic section, such as Figure 5 shown.

[0060] For two adjacent feature points p i and p i+1 , calculate the Euclidean distance d between them i , using the distance formula between two points:

[0061]

[0062] The sum of the Euclidean distances between all two adjacent feature points is taken as the approximate arc length of the characteristic section curve, that is:

[0063]

[0064] Use MATLAB to fit the curve parameters with a quadratic polynomial, generate the coordinate data of the fitting curve, draw images of the original point cloud and the fitting curve, and finally calculate the arc length of the fitting curve and output the result to verify the accuracy of the characteristic section arc length calculation method.

[0065] (5) Feature point mapping, such as Figure 6 As shown, including:

[0066] a) Calculate the mapping distance: After the arc length of the characteristic section is calculated, each feature point of the characteristic section has a corresponding arc length value, which indicates the distance from the point to the starting point of the characteristic section.

[0067] b) Set 2D plane: Select a 2D plane as the projection plane. This plane is usually a plane perpendicular to the characteristic section or a plane tangent to the characteristic section. The choice of plane depends on the projection effect you want to obtain and the characteristics of the data.

[0068] c) Perform coordinate mapping: For each feature point on the feature section, perform the following steps to perform coordinate mapping. The three-dimensional coordinates (x, y, z) of the feature point on the feature section are regarded as vector p. Determine the projection direction based on the arc length value of the feature point on the feature section. If the projection plane is perpendicular to the section, the projection direction is usually the same as the normal vector of the section; if the projection plane is tangent to the section, the projection direction can be obtained by calculating the normal vector of the tangent plane. Translate the coordinates of the feature point on the section in the projection direction or in the opposite direction, and the distance is the arc length value of the point. In this way, the projection coordinates of the point can be obtained on the projection plane.

[0069] d) Visualization: The projected coordinates mapped onto a two-dimensional plane are used for visualization in order to obtain information about the cross-sectional shape and the distribution of feature points.

[0070] (6) Prototype template mapping generation:

[0071] Set the chest point as the fixed point of the mapping plane. For each section, the front and back center points P1-P 37, you only need to change the z coordinate to map to the plane where the chest point is located. The other key points of the template need to be mapped by adding or subtracting the arc length of the cross section based on the x coordinate of the front or back midpoint, such as Figure 7 and Figure 8 shown.

[0072] a) Front piece: For ac section, P1-P 19 The arc length of the curve is used as the sample size data of the front shoulder; for the d section, P1-P 14 As the size data from the armhole to the center front; for the eg section, P1-P 19 The arc length of the curve is used as the size data of the front chest sample; for the h section, P1-P 19 The arc length of the curve is used as the sample size data of the waist of the front piece; for the fi section, the line between P9 is used as the chest and waist dart of the front piece;

[0073] b) Back piece: For ac section, P 19 -P 37 The arc length of the curve is used as the sample size data of the shoulder of the rear piece; for the d section, P 25 -P 37 As the dimension from armhole to center back; for eg section, P 19 -P 37 The arc length of the curve is used as the size data of the back sample of the back piece; for the di section, P 29 The connecting line is used as the back dart

[0074] According to the above size correspondence rules, the coordinate points are mapped to the same xy plane to realize the planarization of the three-dimensional curve, and the Fig. 9 Front and rear panel samples shown.

[0075] (7) Structural modification: Import the mapped coordinates into the reverse engineering software Geomagic controlX 64 to visualize the prototype initial template. Since the prototype initial template is directly mapped from the human neck to waist curve, the collar arc and armhole arc need to be rounded. The rounding rules are as follows:

[0076] a) Horizontal: Keep the horizontal lines such as shoulder line, bust line, bottom line balanced and symmetrical on the left and right sides of the sample to ensure the overall coordination of the prototype.

[0077] b) Vertical: Keep the vertical lines such as the front center line and the back center line vertical in the pattern. When smoothing the side seams and waist darts, fully consider the natural curves of the human body.

[0078] c) Arcs: The arc of the collar, armhole, etc. need to remain smooth and natural, avoiding abrupt turns or sharp corners.

[0079] The adjustment of the neckline is based on the natural shape of the human neck and wearing requirements. The size, shape and depth of the neckline should be determined according to the human neck size, collar design and wearing comfort.

[0080] The correction of the armhole curve should take into account the shape of the human shoulder and upper limbs. The size, shape and depth of the armhole should be determined according to the width of the human shoulder, the length of the upper limbs and the design of the sleeve type. By adjusting the curvature and position of the armhole curve, the connection between the sleeve and the body of the garment will be natural and smooth.

[0081] The modified template is as follows Fig.10 shown.

[0082] Through the above method, the present invention realizes the mapping generation from three-dimensional point cloud data to prototype samples, which can be used for virtual fitting, such as Fig.11 shown.

[0083] The above are only specific embodiments of the present invention, but the technical features of the present invention are not limited thereto. Any simple changes, equivalent replacements or modifications made based on the present invention to solve basically the same technical problems and achieve basically the same technical effects are all included in the protection scope of the present invention.

Claims

1. A method for generating a clothing prototype pattern based on feature point space mapping, characterized in that The steps include: (1) Adopt [TC] 2 The 3D human body scanner obtains 3D point cloud data of the human body; (2) Determine the characteristic cross-sections and characteristic points of the human body; (3) Calculation of arc length of characteristic section: The arc length of characteristic section is approximately obtained by accumulating the Euclidean distance between adjacent characteristic points on the characteristic section; (4) Feature point mapping: Set a two-dimensional projection plane. Each feature point on the feature section has a corresponding arc length value, which represents the distance between the feature point and the starting point of the feature section, i.e., the mapping distance. Determine the projection direction based on the arc length value of the feature point on the feature section. Shift the coordinates of the feature point on the feature section toward the projection direction or in the opposite direction by the mapping distance to obtain the projection coordinates of the feature point. (5) Prototype template mapping generation: Set the fixed point of the projection plane. For each characteristic section, map the characteristic point coordinates to the specified plane by adding or subtracting the arc length of the characteristic section to achieve the planarization of the three-dimensional curve. (6) Structural modification: The mapped coordinates are imported into Geomagic control X 64 software to visualize the prototype.

2. The method for generating a clothing prototype based on feature point space mapping according to claim 1, characterized in that: In step (1), [TC] 2 The 3D human body scanner obtains 3D human body point cloud data and saves them in .wrl and .obj formats respectively; the scanner accuracy is 0.1mm, the scanning speed is 550000 points / second, and the spatial point distance is 0.2mm-3mm.

3. The method for generating a clothing prototype based on feature point space mapping according to claim 1, characterized in that: Ten human body data related to the plate making size are selected from the obtained human body three-dimensional point cloud data, namely net chest circumference, net waist circumference, neck root circumference, front chest height, front chest width, back length, back width, shoulder width (1 / 2), armhole depth, and small shoulder width.

4. The method for generating a clothing prototype pattern based on feature point space mapping according to claim 1, characterized in that: In the step (2), the characteristic cross-section includes 4 basic characteristic cross-sections and 4 auxiliary characteristic cross-sections, the 4 basic characteristic cross-sections include a neck base cross-section, a shoulder cross-section, a chest line cross-section and a waist line cross-section; the 4 auxiliary characteristic cross-sections include an upper chest line cross-section, a neck-shoulder equal section, an upper chest-chest equal section, and a chest-waist equal section.

5. The method for generating a clothing prototype based on feature point space mapping according to claim 1, characterized in that: In the step (2), the feature points include side neck points, front collar points, back neck points, shoulder end points, chest points, waist side seam feature points, front armpit points, armhole points, back armpit points, front center, back center feature points and waist dart feature points, totaling 12 feature points.

6. The method for generating a clothing prototype pattern based on feature point space mapping according to claim 1, characterized in that: In the step (3), after obtaining the arc length of the characteristic section, MATLAB is used to fit the curve parameters with a quadratic polynomial, generate coordinate data of the fitting curve, draw images of the original point cloud and the fitting curve, and finally calculate the length of the fitting curve and output the result to verify the accuracy of the characteristic section arc length calculation method.

7. The method for generating a clothing prototype pattern based on feature point space mapping according to claim 1, characterized in that: The step (4) selects a two-dimensional plane as a projection plane, which is a plane perpendicular to the characteristic section or a plane tangent to the characteristic section; regards the three-dimensional coordinates (x, y, z) of the characteristic point on the characteristic section as a vector p; determines the projection direction according to the arc length value of the characteristic point on the characteristic section curve; if the projection plane is perpendicular to the characteristic section, the projection direction is the same as the normal vector of the characteristic section; if the projection plane is tangent to the characteristic section, the projection direction is obtained by calculating the normal vector of the tangent plane; the coordinates of the characteristic point on the characteristic section are translated in the projection direction or in the opposite direction, and the distance is the arc length value of the characteristic point to obtain the projection coordinates of the characteristic point.

8. The method for generating a clothing prototype based on feature point space mapping according to claim 7, characterized in that: The projection coordinates of the feature points mapped onto the two-dimensional projection plane are used for visualization to obtain information about the feature cross-sectional shape and the distribution of feature points.

9. The method for generating a clothing prototype pattern based on feature point space mapping according to claim 1, characterized in that: The step (6) is visualized, the neckline arc and the armhole arc are rounded, the horizontal lines are symmetrical, and the vertical lines are kept vertical.

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