Scanning bar tailoring method, device, equipment and computer readable storage medium

Abstract

The application discloses a scanning rod cutting method and device, equipment and computer readable storage medium, and relates to the technical field of medical treatment, and comprises the following steps: acquiring a dental arch grid model and a scanning rod radius; determining a scanning rod seed point included in the dental arch grid model, determining all scanning rod grids corresponding to the scanning rod seed point; determining a target fitting direction corresponding to the scanning rod seed point, and determining a projection distance between each scanning rod grid and the target fitting direction; regarding a scanning rod grid with a projection distance less than or equal to the scanning rod radius as a target scanning rod grid, and cutting a grid region included in the target scanning rod grid to obtain a scanning rod. The application improves the cutting accuracy of the scanning rod.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of medical treatment, in particular to a scanning rod cutting method, device, equipment and computer readable storage medium. BACKGROUND

[0002] In dental restoration, the position and direction of the implant in the oral cavity can be obtained by scanning the scanning rod in the model, and the surface matching of the model in the implant database in the design software can obtain the implant information, so as to complete the personalized restoration. Therefore, how to accurately cut the scanning rod in the model plays a crucial role in the successful restoration of teeth.

[0003] However, at present, the scanning rod can only be obtained by cutting the mesh region matching the standard scanning rod in the dental model through the matching of the dental model and the standard scanning rod model. However, in actual scenarios, the direction, size and other factors of the scanning rod are various, and the fixed and single cutting method for cutting the scanning rod has large difference between the cut scanning rod and the actual scanning rod, and the cutting accuracy of the scanning rod is low. SUMMARY

[0004] The main purpose of the present application is to provide a scanning rod cutting method, device, equipment and computer readable computer readable storage medium, which aims to solve the technical problem of how to improve the cutting accuracy of the scanning rod.

[0005] To achieve the above purpose, the present application provides a scanning rod cutting method, which comprises the following steps:

[0006] Obtaining a dental mesh model and a scanning rod radius;

[0007] Determining a scanning rod seed point included in the dental mesh model, and determining all scanning rod meshes corresponding to the scanning rod seed point;

[0008] Determining a target fitting direction corresponding to the scanning rod seed point, and determining a projection distance between each scanning rod mesh and the target fitting direction;

[0009] The scanning rod mesh with a projection distance less than or equal to the scanning rod radius is taken as a target scanning rod mesh, and a mesh region included in the target scanning rod mesh is cut to obtain a scanning rod.

[0010] Optionally, the step of determining the scanning rod seed point included in the dental mesh model comprises:

[0011] Determining all scanning rod sample points included in the dental mesh model, and determining a bounding box corresponding to each scanning rod sample point;

[0012] sequentially detecting whether each of the bounding boxes satisfies a preset seed condition, and taking a bounding box satisfying the preset seed condition as a target bounding box, wherein the preset seed condition comprises matching a major axis length of the detected bounding box with a preset standard part length;

[0013] taking a scanning rod sample point corresponding to the target bounding box as a scanning rod seed point.

[0014] Optionally, the step of determining all scanning rod sample points included in the dental jaw mesh model comprises:

[0015] determining all scanning rod feature points included in the dental jaw mesh model, and determining a first scanning rod feature point with a curvature greater than zero among all the scanning rod feature points, wherein the scanning rod feature point comprises a target model point matching a preset scanning rod feature among all model points included in the dental jaw mesh model;

[0016] determining a normal of the first scanning rod feature point, constructing a ray along a reverse direction of the normal with the first scanning rod feature point as a starting point, and determining all intersection points of the ray and the dental jaw mesh model;

[0017] determining a scanning rod diameter corresponding to the scanning rod radius, and determining a scanning rod sample point based on the first scanning rod feature point if a distance between each of the intersection points and the first scanning rod feature point is less than or equal to the scanning rod diameter.

[0018] Optionally, the step of determining a scanning rod sample point based on the first scanning rod feature point comprises:

[0019] performing density clustering on all the scanning rod feature points with a preset radius to obtain a clustering cluster, and detecting whether the first scanning rod feature point is included in the clustering cluster;

[0020] if the first scanning rod feature point is included in the clustering cluster, taking the first scanning rod feature point as a scanning rod sample point.

[0021] Optionally, the step of determining all scanning rod meshes corresponding to the scanning rod seed point comprises:

[0022] determining all meshes included in the dental jaw mesh model;

[0023] determining a first mesh in which the scanning rod seed point is located according to each of the meshes, and determining a first target mesh topologically connected with the first mesh among all the meshes;

[0024] taking all the first target meshes as scanning rod meshes corresponding to the scanning rod seed point.

[0025] Optionally, the step of determining the target fitting direction corresponding to the scan bar seed point comprises:

[0026] determining a second target grid in the first target grid and having a distance to the scan bar seed point less than the scan bar radius;

[0027] determining an initial fitting direction corresponding to the second target grid, taking scan bar feature points in the second target grid among all the scan bar feature points as second scan bar feature points, and determining an included angle between a normal of each second scan bar feature point and the initial fitting direction;

[0028] determining a target included angle less than a preset angle among all the included angles, and taking a scan bar feature point corresponding to the target included angle as a third scan bar feature point;

[0029] taking a normal of the third scan bar feature point as the target fitting direction corresponding to the scan bar seed point.

[0030] Optionally, the step of determining the initial fitting direction corresponding to the second target grid comprises:

[0031] determining a maximum boundary of the second target grid;

[0032] determining a first center point of the maximum boundary and a second center point of the second target grid;

[0033] taking a direction from the first center point to the second center point as the initial fitting direction corresponding to the second target grid.

[0034] In addition, to achieve the above object, the application further provides a scan bar cutting device, which comprises:

[0035] an acquisition module, configured to acquire a dental arch grid model and a scan bar radius;

[0036] a first determination model, configured to determine a scan bar seed point included in the dental arch grid model, and determine all scan bar grids corresponding to the scan bar seed point;

[0037] a second determination module, configured to determine a target fitting direction corresponding to the scan bar seed point, and determine a projection distance between each scan bar grid and the target fitting direction;

[0038] a cutting module, configured to take a scan bar grid having a projection distance less than or equal to the scan bar radius as a target scan bar grid, and cut a grid region included in the target scan bar grid to obtain a scan bar.

[0039] In addition, to achieve the above object, the application further provides a scanning rod cutting method and device, comprising a memory, a processor and a scanning rod cutting method program stored in the memory and executable on the processor, which realizes the steps of the scanning rod cutting method as above when executed by the processor.

[0040] In addition, to achieve the above object, the application further provides a computer readable storage medium, which stores a scanning rod cutting method program, which realizes the steps of the scanning rod cutting method as above when executed by a processor.

[0041] In the application, after the dental arch grid model and the scanning rod radius are obtained, the scanning rod seed point included in the scanning rod grid model is determined, the target fitting direction corresponding to the scanning rod seed point is determined, all scanning rod grids corresponding to the scanning rod seed point are determined, the projection distance between each scanning rod grid and the target fitting direction is determined, the scanning rod grid with a projection distance smaller than the scanning rod radius is taken as a target scanning rod grid, and the grid region included in the target scanning rod grid is cut to obtain a scanning rod. Thus, compared with the cutting mode of matching the standard scanning rod model in the prior art, the application determines the scanning rod seed point, cuts the grid region of the target scanning rod grid with a projection distance smaller than the scanning rod radius between the scanning rod seed point, and obtains the scanning rod, thereby improving the cutting accuracy of the scanning rod. BRIEF DESCRIPTION OF DRAWINGS

[0042] The object, functional characteristics and advantages of the application will be further described with reference to the embodiments and the accompanying drawings.

[0043] Figure 1 is a terminal device structure schematic diagram of a hardware running environment involved in the embodiment of the application;

[0044] Figure 2 is a flowchart of the first embodiment of the scanning rod cutting method of the application;

[0045] Figure 3 is a scanning rod fitting direction schematic diagram of the scanning rod cutting method of the application;

[0046] Figure 4 is a scanning rod cutting result schematic diagram in the scanning rod cutting method of the application;

[0047] Figure 5 is a scanning rod cutting effect schematic diagram in the scanning rod cutting method of the application;

[0048] Figure 6 is another scanning rod cutting effect schematic diagram in the scanning rod cutting method of the application;

[0049] Figure 7 The scanning rod feature point reverse intersection schematic diagram in the scanning rod tailoring method of the present application is shown.

[0050] Figure 8 The scanning rod sample point density clustering schematic diagram in the scanning rod tailoring method of the present application is shown.

[0051] Figure 9 The device module schematic diagram of the scanning rod tailoring device of the present application is shown. DETAILED DESCRIPTION

[0052] It should be understood that the specific embodiments described herein merely exemplify the present application and do not limit the present application.

[0053] Reference Figure 1 , Figure 1 The scanning rod tailoring method device structure schematic diagram of the hardware running environment involved in the embodiment scheme of the present application is shown.

[0054] As Figure 1 shown, the scanning rod tailoring method device can include a processor 1001, such as a central processing unit (CPU), a communication bus 1002, a user interface 1003, a network interface 1004, and a memory 1005. The communication bus 1002 is used to realize the connection and communication between these components. The user interface 1003 can include a display screen (Display) and an input unit such as a keyboard (Keyboard). The optional user interface 1003 can also include a standard wired interface, a wireless interface. The network interface 1004 can optionally include a standard wired interface, a wireless interface (such as a wireless fidelity (WIreless-FIdelity, WI-FI) interface). The memory 1005 can be a high-speed random access memory (RAM) memory, or a stable non-volatile memory (NVM), such as a magnetic disk memory. The memory 1005 can also be an independent storage device from the aforementioned processor 1001.

[0055] Those skilled in the art can understand Figure 1 that the structure shown in the foregoing embodiments does not constitute a limitation on the scanning rod tailoring method device, and can include more or fewer components than those shown, or combine certain components, or different component arrangements.

[0056] As Figure 1 shown, the memory 1005, as a computer-readable computer-readable storage medium, can include an operation device, a data storage module, a network communication module, a user interface module, and a scanning rod tailoring method program.

[0057] In Figure 1 In the scanning rod cutting method device shown, the network interface 1004 is mainly used for data communication with other devices; the user interface 1003 is mainly used for data interaction with the user; the processor 1001 and the memory 1005 in the scanning rod cutting method device can be arranged in the scanning rod cutting method device, and the scanning rod cutting method device calls the scanning rod cutting method program stored in the memory 1005 through the processor 1001, and executes the scanning rod cutting method provided in the embodiment.

[0058] Plant scanning is divided into oral scanning, model scanning, oral scanning + face bow scanning. For integrated (model + scanning rod + gum completely integrated, model + scanning rod integrated, gum separated alone), split type (model, scanning rod, gum completely separated model (model may have gum on the top), scanning rod + gum) scanning piece, the scanning rod needs to be cut out for registration with the standard rod.

[0059] The current scanning rod cutting method has the following problems: 1) The gum or model is too much adhered to the scanning rod, the position of the scanning rod can be recognized, but the correct grid area cannot be cut out; 2) The number of scanning rods cannot be automatically recognized.

[0060] Based on the above phenomenon, referring to Figure 2 The present application provides a scanning rod cutting method. In the first embodiment of the scanning rod cutting method, the scanning rod cutting method comprises the following steps:

[0061] Step S10, obtaining a dental arch grid model and a scanning rod radius;

[0062] The dental arch grid model is a scanning model including a scanning rod and a gum. The scanning rod radius can be input by the user, or a default scanning rod radius can be preset. When the user does not input the scanning rod radius, the default scanning rod radius is selected. In addition, if the dental arch grid model includes a plurality of scanning rods, the user can also input the number of scanning rods and the scanning rod radius of each scanning rod. Each scanning rod can be cut by the cutting method of the embodiment.

[0063] Step S20, determining a scanning rod seed point included in the dental arch grid model, and determining all scanning rod grids corresponding to the scanning rod seed point;

[0064] Screening the scan rod seed point in the dental arch grid model, the screening method can be as follows: projecting all scan rod feature points included in the dental arch grid model to the occlusal direction of the dental arch, sorting according to the projection height from high to low and traversing, and cutting out the region with each scan rod feature point as the starting point and the distance from the point being less than or equal to the diameter of the scan rod. As known by those skilled in the art, each connected region in the grid is a component, and the components are not connected to each other. After removing other small components other than the largest connected region of the grid, the OBB (Oriented Bounding Box) bounding box is calculated, that is, the largest connected region of the grid is retained as region 1. It is judged whether the main axis length of the OBB bounding box matches the preset standard part length. If the match is successful, the scan rod feature point is taken as the scan rod seed point. The preset standard part length can be set by the user in advance and can be a value or a length range, such as 0.8 cm to 1.2 cm. When the preset standard part length is a length range, if the main axis length of the OBB bounding box is within the range, the main axis length of the OBB bounding box matches the preset standard part length successfully, otherwise, the match fails.

[0065] It should be noted that the OBB bounding box calculation method can be as follows:

[0066] 1) Calculate the center point of the model: calculate the average value of the coordinates of all grid vertices included in region 1 to obtain the center point coordinates, and the center point is denoted as p.

[0067] 2) Calculate the covariance matrix: calculate the deviation vectors of all grid vertices in region 1 from the center point p. Determine the covariance matrix based on all deviation vectors.

[0068] 3) Perform eigenvalue decomposition on the covariance matrix: calculate the eigenvalues and corresponding eigenvectors of the covariance matrix.

[0069] 4) Determine the main axis direction (the three directions of the OBB coordinate system): select the eigenvector with the largest eigenvalue of the covariance matrix as the first main axis direction. Select the eigenvector with the second largest eigenvalue of the covariance matrix as the second main axis direction. Select the eigenvector with the third largest eigenvalue of the covariance matrix as the third main axis direction.

[0070] 4) Determine the main axis length: calculate the difference between the minimum value and the maximum value of the projection of all vertices in each main axis direction to obtain the main axis length.

[0071] 5) Construct the OBB bounding box: construct the OBB bounding box based on the center point p as the origin and the main axis direction and the main axis length.

[0072] If the spindle length of the OBB bounding box matches the preset standard part length in all three spindle directions, then the spindle length of the OBB bounding box is successfully matched with the preset standard part length.

[0073] In one embodiment, the step of determining all scan rod grids corresponding to the scan rod seed point includes:

[0074] Step A10: Determine all the meshes included in the dental mesh model;

[0075] Step A20: Determine the first grid where the scanning rod seed point is located based on each of the grids, and determine the first target grid that is topologically connected to the first grid among all the grids;

[0076] Step A30: Use all the first target grids as the scan rod grids corresponding to the scan rod seed points.

[0077] The first target grid, which is topologically connected to the first grid where the scanning rod seed point is located, is used as the scanning rod grid corresponding to the scanning rod. This ensures that the scanning rod grids are topologically connected. The scanning rod is then clipped from the scanning rod grids that are topologically connected to the grid where the scanning rod seed point is located, reducing the number of grids to be filtered and improving the clipping efficiency and accuracy of the scanning rod.

[0078] Step S30: Determine the target fitting direction corresponding to the seed point of the scanning rod, and determine the projection distance between each scanning rod grid and the target fitting direction;

[0079] The mapping relationship between the coordinates of different scanning rod seed points and the target fitting direction can be preset, and the target fitting direction corresponding to the scanning rod seed point can be determined based on the preset mapping relationship. The target fitting direction can be referenced. Figure 3 The direction indicated by d2 in the diagram.

[0080] Step S40: The scanning rod grid with a projection distance less than or equal to the scanning rod radius is taken as the target scanning rod grid, and the grid area included in the target scanning rod grid is trimmed to obtain the scanning rod.

[0081] The topology-continuous grid with a projection distance to the target fitting direction being less than or equal to the scanning rod radius is obtained as a target scanning rod grid. The grid region included in the target scanning rod grid is cropped to obtain a scanning rod. Further, an included angle between a normal of each scanning rod grid and the target fitting direction can be calculated, and the topology-continuous grid with a projection distance to the target fitting direction being less than or equal to the scanning rod radius and an included angle between the topology-continuous grid and the target fitting direction being less than a preset angle is obtained as a target scanning rod grid. That is, the scanning rod grid with the projection distance being less than or equal to the scanning rod radius is taken as a first scanning rod grid, a normal of each first scanning rod grid is determined, an included angle between each normal and the target fitting direction is determined, and the first scanning rod grid with the included angle being less than a preset angle is taken as a target scanning rod grid. The cropping to obtain a scanning rod can refer to Figure 4

[0082] The scanning rod cropping method of the embodiment can be used to crop a given number of scanning rods for a split-type or integrated-type dental scanning model. The scanning rod cropping effect for the split-type scanning model can refer to Figure 5 Figure 6

[0083] In the embodiment, after the dental model and the scanning rod radius are obtained, a scanning rod seed point included in the scanning rod grid model is determined, a target fitting direction corresponding to the scanning rod seed point is determined, all scanning rod grids corresponding to the scanning rod seed point are determined, a projection distance between each scanning rod grid and the target fitting direction is determined, a scanning rod grid with the projection distance being less than the scanning rod radius is taken as a target scanning rod grid, and a grid region included in the target scanning rod grid is cropped to obtain a scanning rod. Thus, compared with the cropping method of matching a standard scanning rod model in the prior art, the embodiment of the application determines a scanning rod seed point, crops a grid region of a target scanning rod grid with a projection distance between the scanning rod seed point being less than a scanning rod radius, and thus improves the cropping accuracy of the scanning rod.

[0084] Further, based on the first embodiment of the application, a second embodiment of the scanning rod cropping method of the application is provided. The same or similar contents as the first embodiment can refer to the foregoing description, and will not be described in detail. In the embodiment, the step S20 of the foregoing embodiment is refined, and includes the following steps.

[0085] In step B10, all scanning rod sample points included in the dental model are determined, and a bounding box corresponding to each scanning rod sample point is determined.

[0086] ​​​In an embodiment, the step of determining all scan rod sample points included in the dental arch mesh model comprises:

[0087] Step C10, determining all scan rod feature points included in the dental arch mesh model, determining first scan rod feature points with curvature greater than zero among all the scan rod feature points, wherein the scan rod feature points include target model points in all model points included in the dental arch mesh model that match preset scan rod features;

[0088] As known by those skilled in the art, scan rod feature points can be determined according to preset scan rod feature sets, such as point color value features, point position features, etc. For example, if the preset feature set is point color value in interval range A, all model points with color value in interval range A are obtained to obtain scan rod feature points.

[0089] The point curvature of all scan rod feature points is calculated through the mesh model to obtain first scan rod feature points with curvature greater than 0.

[0090] Step C20, determining the normal of the first scan rod feature point, constructing a ray along the reverse direction of the normal with the first scan rod feature point as the starting point, and determining all intersection points of the ray and the dental arch mesh model.

[0091] As known by those skilled in the art, a second mesh in which the first scan rod feature point is located is determined, all third meshes in the dental arch mesh model that are topologically connected to the second mesh are determined, a ray is constructed along the reverse direction of the normal of the first scan rod feature point with the first scan rod feature point as the starting point, and all intersection points of the ray and the dental arch mesh model are determined, wherein the all intersection points can be intersection points of the ray and each third mesh, i.e. intersection points of the first scan rod feature point along the reverse direction of the normal with itself. Refer to Figure 7 for the intersection point diagram.

[0092] Step C30, determining a scan rod diameter corresponding to the scan rod radius, if the distance between each intersection point and the first scan rod feature point is less than or equal to the scan rod diameter, determining a scan rod sample point based on the first scan rod feature point.

[0093] In a feasible implementation, all intersection points of the reverse direction of the normal with itself and the scan rod feature points with a distance less than or equal to the scan rod diameter can be taken as scan rod sample points.

[0094] In the embodiment, the scanning rod feature points with the curvature greater than zero and the scanning rod feature points with all intersection points of the reverse direction along the normal and the intersection with itself and the distance from the intersection points to the scanning rod feature points themselves less than or equal to the diameter of the scanning rod are selected as the scanning rod sample points, so that the range of the sample points can be reduced and the selection efficiency of the subsequent selection of the scanning rod seed points can be improved.

[0095] In step B20, whether each bounding box meets the preset seed condition is detected in sequence, and the bounding box meeting the preset seed condition is taken as a target bounding box, wherein the preset seed condition includes that the major axis length of the detected bounding box matches the preset standard part length.

[0096] In step B30, the scanning rod sample point corresponding to the target bounding box is taken as a scanning rod seed point.

[0097] The bounding box has multiple major axes, and the major axis length of each major axis matches the preset standard part length, so that whether the bounding box meets the preset seed condition is determined. For example, in a scene, assuming that the bounding box corresponding to a scanning rod sample point m1 has three major axes X, Y and Z, the preset standard part length is 0.8 cm to 1.2 cm, the major axis length of the major axis X of the bounding box is 1 cm, the major axis length of the major axis Y of the bounding box is 0.6 cm, and the major axis length of the major axis Z of the bounding box is 1.1 cm, so that the major axis length of the major axis Y of the bounding box does not match the preset standard part length, and the bounding box does not meet the preset seed condition. In another scene, assuming that the bounding box corresponding to a scanning rod sample point m2 has three major axes X, Y and Z, the preset standard part length is 0.8 cm to 1.2 cm, the major axis length of the major axis X of the bounding box is 0.8 cm, the major axis length of the major axis Y of the bounding box is 0.9 cm, and the major axis length of the major axis Z of the bounding box is 1 cm, so that the major axis length of each major axis of the bounding box matches the preset standard part length, and the bounding box meets the preset seed condition, and the scanning rod sample point m2 can be taken as a scanning rod seed point.

[0098] In another feasible embodiment, the number of the major axes of the bounding box matching the preset standard part length is greater than or equal to a preset number (such as 1, 2, 3, etc.), so that whether the bounding box meets the preset seed condition is determined. For example, assuming that the preset number is 1, the bounding box corresponding to a scanning rod sample point m1 has three major axes X, Y and Z, the preset standard part length is 0.8 cm to 1.2 cm, the major axis length of the major axis X of the bounding box is 1 cm, the major axis length of the major axis Y of the bounding box is 0.6 cm, and the major axis length of the major axis Z of the bounding box is 1.1 cm, so that the number of the major axes of the bounding box matching the preset standard part length is 2, which is greater than the preset number 1, the bounding box meets the preset seed condition, and the scanning rod sample point m1 can be taken as a scanning rod seed point.

[0099] In the embodiment, the scanning rod sample point meeting the preset seed condition is taken as the scanning rod seed point, wherein the preset seed condition includes that the major axis length of the bounding box corresponding to the scanning rod sample point matches the preset standard part length, and the scanning rod sample point with the major axis length of the bounding box matching the preset standard part length is selected as the scanning rod seed point, so that the effectiveness of the selected scanning rod seed point is ensured.

[0100] In an embodiment, the step of determining the scanning rod sample point based on the first scanning rod feature point includes:

[0101] Step D10, density clustering is performed on all the scanning rod feature points with a preset radius to obtain a clustering cluster, and it is detected whether the first scanning rod feature point is contained in the clustering cluster;

[0102] Step D20, if the first scanning rod feature point is contained in the clustering cluster, the first scanning rod feature point is taken as the scanning rod sample point.

[0103] A feasible density clustering method can be as follows:

[0104] 1) Initialization: all scanning rod feature points are marked as unvisited.

[0105] 2) Iteration of sample set: each scanning rod feature point p in the sample set is iterated in turn, if p has been visited, the point is skipped; otherwise, p is marked as visited, and the number of sample points in the preset radius neighborhood of p is obtained, wherein the preset radius neighborhood can be an ε-neighborhood.

[0106] 3) Core object: if the number of sample points in the preset radius neighborhood is greater than or equal to a preset value, p is marked as a core object, and p is added to a new cluster.

[0107] 4) Density direct: for the core object p, the scanning rod feature points in the preset radius neighborhood of p are added to the cluster, and the scanning rod feature points in the preset radius neighborhood of these scanning rod feature points are recursively added to the cluster, and the scanning rod feature points added to the cluster are marked as visited.

[0108] 5) Density connection: for a non-core object q, if q is located in the preset radius neighborhood of a core object p in a cluster, q is added to the cluster.

[0109] 6) Complete clustering: when all sample points are marked as visited, the clustering process ends.

[0110] 7) Output result: each cluster and the scanning rod feature points contained therein are taken as the clustering result and output. Meanwhile, the sample points not contained in any cluster are regarded as noise points.

[0111] The clustering process can refer toFigure 8 As shown, the clustering mode of the density clustering can refer to the prior art, and the embodiment provides a possible density clustering mode, which does not limit the density clustering mode.

[0112] In the embodiment, the first scan rod feature point is determined whether it is contained in the clustering cluster, if the first scan rod feature point is contained in the clustering cluster, the first scan rod feature point is taken as the scan rod sample point. It can be understood that the density of the scan rod feature points near the scan rod is large, and some outlier scan rod feature points are removed, so that the scan rod seed point can be more accurately identified. The reduction of the scan rod feature points makes the number of selection operation of the subsequent scan rod seed point less, and the cutting speed of the scan rod is improved.

[0113] In an embodiment, the step of determining the target fitting direction corresponding to the scan rod seed point comprises:

[0114] Step E10, determining a second target grid in the first target grid and having a distance from the scan rod seed point less than the scan rod radius;

[0115] Step E20, determining an initial fitting direction corresponding to the second target grid, taking the scan rod feature points in the second target grid among all the scan rod feature points as second scan rod feature points, and determining the included angle between the normal of each second scan rod feature point and the initial fitting direction;

[0116] Step E30, determining a target included angle less than a preset angle among all the included angles, and taking the scan rod feature point corresponding to the target included angle as a third scan rod feature point;

[0117] Step E40, taking the normal of the third scan rod feature point as the target fitting direction corresponding to the scan rod seed point.

[0118] If there are multiple third scan rod feature points, the normal of each third scan rod feature point is vector summed to obtain a direction, and the direction is taken as the target fitting direction corresponding to the scan rod seed point. It should be noted that the second scan rod feature point in the embodiment includes all points in the newly cut single grid which are traversed from the scan rod seed point and have a distance less than the scan rod radius, that is, all points in the newly cut single grid which are traversed from the scan rod seed point.

[0119] An angle between a normal of the second scan bar feature point and the initial fitting direction is determined, and a scan bar feature point with an angle less than a preset angle is taken as a third scan bar feature point, where the preset angle can be set by a user according to an actual situation, such as 55 degrees, 60 degrees, 65 degrees, etc. That is, a point set composed of the third scan bar feature points can be obtained, an average coordinate of all the third scan bar feature points in the point set is calculated, a center point c2 of the point set can be obtained, and a target fitting direction d2 passing through the point c2 is determined, as shown in Figure 3

[0120] In an embodiment, the step of determining the initial fitting direction corresponding to the second target grid comprises:

[0121] Step F10, determining a maximum boundary of the second target grid;

[0122] Step F20, determining a first center point of the maximum boundary and a second center point of the second target grid;

[0123] Step F30, taking a direction from the first center point to the second center point as the initial fitting direction corresponding to the second target grid.

[0124] The maximum boundary is a boundary with the largest grid radius, the first center point of the maximum boundary and the second center point of the second target grid are determined, and the direction from the first center point to the second center point is taken as the initial fitting direction, as shown in Figure 3 Figure 3 where d1 is the initial fitting direction, the bottom boundary is the maximum boundary, the center point is the first center point, and the other point in the direction of d1 is the second center point of the second target grid.

[0125] In the embodiment, the bottom boundary of the scan bar is preliminarily determined by determining the maximum boundary of the second target grid, the initial fitting direction is obtained by taking the direction from the first center point of the maximum boundary to the second center point of the second target grid, the third scan bar feature point with an angle less than a preset angle between a normal and the initial fitting direction is selected, and the target fitting direction corresponding to the scan bar seed point is determined based on the third scan bar feature point, thereby improving the effectiveness and accuracy of the obtained target fitting direction.

[0126] To help understand the technical concept or technical principle of the present application, a specific embodiment is listed:

[0127] The scan bar cutting process in the specific embodiment is as follows:

[0128] ​​1) By bite direction, the curvature of the point, the direction of the point, the distance of the point along the normal and itself intersection, the scanning rod sample points are screened out. By calculating the point curvature of all scanning rod feature points of the grid model, the point set with curvature greater than 0 is obtained, and the intersection point of all scanning rod feature points in the point set along the normal is obtained. The distance of all intersection points to itself is less than the diameter of the scanning rod, and the scanning rod feature point is used as the scanning rod sample point.

[0129] 2) Based on density clustering, the data points are divided into different clusters by using the density estimation result, and the clusters with high density are automatically identified, and the low density area is regarded as noise points.

[0130] The flow of density clustering can be as follows:

[0131] Initialization: all scanning rod sample points are marked as unvisited.

[0132] Traverse the sample set: for each scanning rod sample point p in the sample set, if p has been visited, skip the point; otherwise, mark p as visited, and get the number of scanning rod sample points in its ε-neighborhood.

[0133] Core object: if the number of scanning rod sample points in the ε-neighborhood is greater than or equal to the preset value, mark p as a core object, and add p to a new cluster.

[0134] Density direct: for the core object p, add the sample points in its ε-neighborhood to the cluster, and recursively add the sample points in the ε-neighborhood of these points to the cluster.

[0135] Density connection: for non-core object q, if q is located in the ε-neighborhood of core object p in a cluster, add q to the cluster.

[0136] Complete clustering: when all scanning rod sample points are visited, the clustering process ends.

[0137] Output result: output each cluster and its contained sample points as the clustering result. At the same time, the sample points not contained by any cluster are regarded as noise points.

[0138] 3) Project all scanning rod sample points contained in the clustering cluster onto the bite direction, sort and traverse according to the projection height from high to low, and cut out each scanning rod sample point as the starting point to query the region less than or equal to the scanning rod diameter from the point. After removing the small components, calculate the OBB bounding box, and according to whether the length of the main axis of the bounding box matches the length of the preset standard part, if it matches, mark the scanning rod sample point corresponding to the bounding box as a scanning rod seed point, otherwise do not mark it as a scanning rod seed point.

[0139] The way to calculate the OBB bounding box can be as follows:

[0140] Center point of the computational model: calculate the average of the coordinates of all vertices in the grid region to get the center point coordinates.

[0141] Covariance matrix calculation: for each vertex, calculate its deviation vector from the center point. Calculate the covariance matrix according to all deviation vectors.

[0142] Eigenvalue decomposition of the covariance matrix: calculate the eigenvalues and corresponding eigenvectors of the covariance matrix.

[0143] Determine the principal axis direction (three directions of the OBB coordinate system): select the eigenvector with the largest eigenvalue of the covariance matrix as the first principal axis direction. Select the eigenvector with the second largest eigenvalue of the covariance matrix as the second principal axis direction. Select the eigenvector with the third largest eigenvalue of the covariance matrix as the third principal axis direction.

[0144] Determine the principal axis length: calculate the difference between the minimum and maximum values of the projection of all vertices in each principal axis direction to get the principal axis length.

[0145] Construct the OBB bounding box: use the center point, principal axis direction and principal axis length to define the position and size of the OBB, and construct the OBB bounding box.

[0146] 4) Starting from the scan rod seed point, traverse the continuous grid with a distance less than the scan rod radius and clip it into a separate grid, find the boundary with the largest radius of this grid, connect the midpoint of the center of the grid and the largest boundary as the approximate direction d1 of the current scan rod, find the point set with the angle between the normal of the point and d1 less than the preset angle, calculate the center c2 and the average normal (i.e. the vector sum of the normal) d2 of the point set.

[0147] 5) Starting from the scan rod seed point, clip the topologically continuous grid with a projection distance to the fitting direction d2 less than or equal to the scan rod radius, clip the bottom boundary to get the scan rod.

[0148] In addition, with reference to Figure 9 , the application also provides a scan rod clipping device, which comprises:

[0149] An acquisition module 10 is configured to acquire a dental arch grid model and a scan rod radius.

[0150] A first determination model 20 is configured to determine a scan rod seed point included in the dental arch grid model, and determine all scan rod grids corresponding to the scan rod seed point.

[0151] A second determination module 30 is configured to determine a target fitting direction corresponding to the scan rod seed point, and determine a projection distance between each scan rod grid and the target fitting direction.

[0152] The clipping module 40 is configured to clip the scanning rod grid whose projection distance is less than or equal to the scanning rod radius as a target scanning rod grid, and clip the scanning rod in the grid area included in the target scanning rod grid.

[0153] In addition, the present application further provides a scanning rod clipping device. The scanning rod clipping device comprises a memory, a processor, and a scanning rod clipping program stored in the memory and executable on the processor. When the scanning rod clipping program is executed by the processor, the steps of the scanning rod clipping method described above are implemented.

[0154] The specific implementation of the scanning rod clipping method and device of the present application is basically the same as that of the above-mentioned scanning rod clipping method, and will not be repeated here.

[0155] In addition, in order to achieve the above-mentioned purpose, the present application further provides a computer readable storage medium, and the computer readable storage medium stores a scanning rod clipping program. When the scanning rod clipping program is executed by a processor, the steps of the scanning rod clipping method described above are implemented.

[0156] The specific implementation of the computer readable storage medium of the present application is basically the same as that of the above-mentioned scanning rod clipping method, and will not be repeated here.

[0157] It should be noted that in this paper, the term "including", "containing" or any other variant thereof is intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed, or includes elements inherent to such process, method, article or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of other identical elements in the process, method, article or device including the element.

[0158] The above-mentioned serial numbers of the embodiments of the present application are only for description, and do not represent the advantages and disadvantages of the embodiments.

[0159] Those skilled in the art can clearly understand the above-mentioned embodiment method can be realized by means of software and the necessary general hardware platform, of course, can also be through hardware, but in many cases the former is a better embodiment. Based on such understanding, the technical solutions of the present application essentially or say the part of the prior art contribution can be embodied in the form of software products, the computer software product is stored in a computer readable computer readable storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, including a number of instructions to make a terminal device (may be a mobile phone, computer, cloud server, air conditioner, or network equipment, etc.) executes the method described in various embodiments of the present application.

[0160] The above is only the preferred embodiment of the present application, not therefore limit the patent scope of the present application, all equivalent structures or equivalent process transformation using the contents of the present application specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A method of scanning bar tailoring, characterized by, The scanning rod cutting method comprises the following steps: Obtaining a dental arch grid model and a scanning rod radius; Determining all scanning rod sample points included in the dental arch grid model, and determining a bounding box corresponding to each scanning rod sample point; sequentially detecting whether each bounding box meets a preset seed condition, and taking the bounding box meeting the preset seed condition as a target bounding box, wherein the preset seed condition comprises matching the major axis length of the detected bounding box with a preset standard part length; Taking the scanning rod sample point corresponding to the target bounding box as a scanning rod seed point, and determining all scanning rod grids corresponding to the scanning rod seed point; Determining a second target grid between each scanning rod grid and the scanning rod seed point, wherein the distance between the second target grid and the scanning rod seed point is less than the scanning rod radius; Determining an initial fitting direction corresponding to the second target grid, taking the scanning rod feature points in the second target grid among all scanning rod feature points as second scanning rod feature points, and determining the included angle between the normal of each second scanning rod feature point and the initial fitting direction, wherein the scanning rod feature points comprise target model points among all model points included in the dental arch grid model, which match a preset scanning rod feature; Determining a target included angle less than a preset angle among all included angles, and taking the scanning rod feature point corresponding to the target included angle as a third scanning rod feature point; Taking the normal of the third scanning rod feature point as a target fitting direction corresponding to the scanning rod seed point, and determining the projection distance between each scanning rod grid and the target fitting direction; Taking the scanning rod grid with a projection distance less than or equal to the scanning rod radius as a target scanning rod grid, and cutting the grid region included in the target scanning rod grid to obtain a scanning rod.

2. The scan bar tailoring method of claim 1, wherein, The step of determining all scanning rod sample points included in the dental arch grid model comprises: Determining all scanning rod feature points included in the dental arch grid model, and determining a first scanning rod feature point with a curvature greater than zero among all scanning rod feature points; Determining the normal of the first scanning rod feature point, constructing a ray in the reverse direction of the normal with the first scanning rod feature point as the starting point, and determining all intersection points of the ray and the dental arch grid model; Determining a scanning rod diameter corresponding to the scanning rod radius, and if the distance between each intersection point and the first scanning rod feature point is less than or equal to the scanning rod diameter, determining a scanning rod sample point based on the first scanning rod feature point.

3. The scan bar tailoring method of claim 2, wherein, The step of determining a scanning rod sample point based on the first scanning rod feature point comprises: Performing density clustering on all scanning rod feature points with a preset radius to obtain a clustering cluster, and detecting whether the first scanning rod feature point is included in the clustering cluster; If the first scanning rod feature point is included in the clustering cluster, taking the first scanning rod feature point as a scanning rod sample point.

4. The scan bar tailoring method of claim 1, wherein, The step of determining all scanning rod grids corresponding to the scanning rod seed point comprises: Determining all grids included in the dental arch grid model; Determining a first grid where the scanning rod seed point is located according to each grid, and determining a first target grid topologically connected with the first grid among all grids; All the first target meshes are taken as scanning rod meshes corresponding to the scanning rod seed points.

5. The scan bar tailoring method of claim 1, wherein, The step of determining the initial fitting direction corresponding to the second target mesh comprises: determining a maximum boundary of the second target mesh; determining a first center point of the maximum boundary and a second center point of the second target mesh; taking a direction from the first center point to the second center point as the initial fitting direction corresponding to the second target mesh.

6. A scanning bar cutting device, characterized by The scanning rod cutting device comprises: An acquisition module is configured to acquire a dental arch mesh model and a scanning rod radius. A first determination module is configured to determine all scanning rod sample points included in the dental arch mesh model, determine an enclosing box corresponding to each scanning rod sample point, and sequentially detect whether each enclosing box meets a preset seed condition. The preset seed condition comprises detecting that a main axis length of the enclosing box matches a preset standard length. The target enclosing box corresponding to the scanning rod sample point is taken as a scanning rod seed point, and all scanning rod meshes corresponding to the scanning rod seed point are determined. A second determination module is configured to determine a second target mesh having a distance to the scanning rod seed point less than the scanning rod radius, determine an initial fitting direction corresponding to the second target mesh, take a scanning rod feature point in the second target mesh as a second scanning rod feature point, determine an included angle between a normal of each second scanning rod feature point and the initial fitting direction, determine a target included angle less than a preset angle among all the included angles, take a scanning rod feature point corresponding to the target included angle as a third scanning rod feature point, take a normal of the third scanning rod feature point as a target fitting direction corresponding to the scanning rod seed point, and determine a projection distance between each scanning rod mesh and the target fitting direction. A cutting module is configured to take a scanning rod mesh having a projection distance less than or equal to the scanning rod radius as a target scanning rod mesh, and cut a mesh region included in the target scanning rod mesh to obtain a scanning rod.

7. A scan bar tailoring apparatus, characterized by, The scanning rod cutting device comprises a memory, a processor, and a scanning rod cutting program stored on the memory and executable on the processor. When the scanning rod cutting program is executed by the processor, the steps of the scanning rod cutting method according to any one of claims 1 to 5 are implemented.

8. A computer-readable storage medium, characterized in that, A scanning rod cutting program is stored on the computer readable storage medium. When the scanning rod cutting program is executed by the processor, the steps of the scanning rod cutting method according to any one of claims 1 to 5 are implemented.

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