A method for surface reconstruction of a three-dimensional model

Abstract

The application belongs to the technical field of image processing, and discloses a three-dimensional model surface reconstruction method, which constructs a general cubic reconstruction index table, which includes all combinations of six face patches of a cubic participating in reconstruction and corresponding face patch reconstruction masks, vertex reconstruction masks and vertex indexes; the face patch reconstruction mask is a six-bit binary number, and the face patch corresponding to the bit with a value of 1 participates in reconstruction; the vertex reconstruction mask is an eight-bit binary number, and the vertex corresponding to the bit with a value of 1 participates in reconstruction; three-dimensional body data is obtained, each voxel has three-dimensional indexes and a binary state; the binary state of adjacent voxels is used to obtain the face patch reconstruction mask, and the voxel is a reconstruction effective voxel when the binary state is greater than 0; a reconstruction effective voxel set and a face patch reconstruction mask set are obtained, and a face patch array set participating in reconstruction and a vertex coordinate set are obtained according to the sets and the general cubic reconstruction index table; the face patch array is the global index of four vertices constituting a reconstruction face patch; and a reconstruction surface model is constructed. The generation efficiency and speed of a dynamic surface model are improved.

Description

Technical Field

[0001] This invention belongs to the field of image processing technology, specifically, it relates to a method for reconstructing the surface of a three-dimensional model. Background Technology

[0002] In numerous fields such as industrial inspection, medical imaging, and scientific computing, 3D volumetric data has become an indispensable core data format. Industrial computed tomography (CT) can non-destructively acquire high-precision 3D structural information about the interior of objects; medical imaging technologies such as CT and MRI generate detailed 3D data describing human organs, tissues, and lesions. This volumetric data is essentially a 3D regular mesh containing scalar attributes such as density and material properties. How to efficiently and accurately reconstruct a surface model from this mesh for visualization and interactive operation is a crucial and challenging issue.

[0003] Traditional 3D surface reconstruction algorithms (such as the classic Marching Cubes algorithm), while versatile, often face efficiency bottlenecks when processing massive volumes of data and struggle to meet the stringent performance requirements of real-time interactive applications. This is particularly true in scenarios such as real-time surgical simulations, online inspection of industrial parts, and virtual sculpting and editing, where users not only need to observe static models but also perform dynamic, visual interactive operations (such as cutting, smearing, deformation, and Boolean operations). These operations require the system to provide immediate feedback on modifications, placing extremely high demands on the speed and flexibility of the underlying reconstruction algorithms. Summary of the Invention

[0004] This invention provides a method for reconstructing the surface of a three-dimensional model. It uses a predefined topological structure to generate a voxel cube reconstruction index table. By looking up the table, the neighborhood state of the voxel is mapped to the set of surface patches to be generated, making the reconstructed surface visible to the patches facing the external space. This simplifies the reconstruction process and improves the generation efficiency and speed of dynamic surface models.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A method for reconstructing the surface of a three-dimensional model includes the following steps.

[0007] A general cube reconstruction index table is constructed, which includes all combinations of the six faces of the cube participating in reconstruction and the corresponding face reconstruction mask, vertex reconstruction mask, and vertex index; the face reconstruction mask is a six-bit binary number, where a bit with a value of 1 represents the corresponding face participating in reconstruction; the vertex reconstruction mask is an eight-bit binary number, where a bit with a value of 1 represents the corresponding vertex participating in reconstruction.

[0008] Acquire three-dimensional volume data, which includes multiple voxels; each voxel has a defined three-dimensional index, binary state, and spatial size; the binary state includes an active state and an inactive state;

[0009] The patch reconstruction mask is obtained based on the binary state of the adjacent voxels in the active state. When the value is greater than 0, the voxel is a valid voxel for reconstruction. The set of valid voxels for reconstruction C and the corresponding set of patch reconstruction masks B are obtained.

[0010] The set of effective voxels for reconstruction C, the set of face reconstruction masks B, and the general cube reconstruction index table are used to obtain the set of face arrays and the set of vertex coordinates for reconstruction; the face array is the global index of the four vertices that make up the reconstructed face.

[0011] The reconstructed surface model is constructed based on the set of face arrays and the set of vertex coordinates.

[0012] In some specific embodiments, when acquiring the reconstructed effective voxels, the space of the three-dimensional volume data is divided into multiple spatial regions, and the reconstructed effective voxels of different spatial regions are acquired in parallel using multi-threading.

[0013] In some specific embodiments, the adjacent voxels are implemented using a global index of each voxel, including:

[0014] The three-dimensional volume data has a defined three-dimensional dimension. The three-dimensional index of each voxel is: ;

[0015] The global index of the voxel is: ;

[0016] The global indices of each adjacent voxel are as follows: , , , , , .

[0017] In some specific embodiments, the vertex indices participating in the reconstruction in the general cube reconstruction index table are represented by a three-dimensional array; the first dimension is the sequence number of the face combination; the second dimension is the face number under the face combination sequence number; and the third dimension is the vertex number corresponding to the face number.

[0018] In some specific embodiments, the vertex coordinates of each effective voxel are obtained based on the three-dimensional index and spatial size of the voxel, including:

[0019] According to the three-dimensional index of the voxel The center point coordinates of the voxel are obtained by the transformation matrix T from discrete index coordinates to world coordinates. ;

[0020] Based on the spatial dimensions of the voxel and the coordinates of the center point The coordinates of the eight vertices of the voxel are obtained as follows: , , , , , , , ;

[0021] in,

[0022] This is a function for the coordinates of voxel vertices, whose parameter is the voxel vertex index;

[0023] , , , , , .

[0024] In some specific embodiments, obtaining the set of vertex coordinates participating in the reconstruction based on the set of effective voxels for reconstruction, the set of facet reconstruction masks, and the general cube reconstruction index table includes:

[0025] Each of the reconstructed effective voxels in the reconstructed effective voxel set is renumbered and indexed. ;

[0026] voxels The number of vertices involved in the outer surface reconstruction is Each vertex The coordinates are calculated using the following formula:

[0027] ;

[0028] In the formula, , for The binary representation of each bit (0 or 1), the function voxels The local vertex index is converted to the world coordinates of that vertex;

[0029] The set of vertex coordinates is:

[0030] .

[0031] In some specific embodiments, obtaining the set of facet arrays participating in reconstruction based on the set of effective reconstructed voxels, the set of facet reconstruction masks, and the general cube reconstruction index table includes:

[0032] Obtain the patch offset of each of the reconstructed effective voxels. and vertex offset :

[0033] , ;

[0034] in, The function is the number of patches involved in the reconstruction of the effective voxels, and its parameter is the patch reconstruction mask; The function is the number of vertices participating in the reconstruction of the effective voxels, and its parameter is the vertex reconstruction mask;

[0035] Obtain the set of face arrays:

[0036] ;

[0037] in, ; N represents the number of effective voxels in the reconstruction. The function is the index of each vertex participating in the reconstruction of the effective voxel, with the parameter being the three-dimensional array; , This is the global indexing function for vertices.

[0038] In some specific embodiments, the construction of the face array and the acquisition of vertex coordinates are both performed using multi-threading.

[0039] In some specific embodiments, an absolute tolerance is set. Merging distance is less than The vertices are used to optimize the reconstructed surface model.

[0040] In some specific embodiments, all quadrilateral patches in the reconstructed surface model are decomposed into triangular patches to obtain a pure triangular mesh surface model;

[0041] The pure triangular mesh surface model is smoothed using a smoothing filter based on the window Sinc function to obtain the final smooth mesh model.

[0042] Compared with the prior art, the advantages and positive effects of the present invention are as follows: The three-dimensional model surface reconstruction method of the present invention predefines the combination of the six faces of the cube participating in the reconstruction and generates a general cube reconstruction index table with corresponding topological structure. It also uses an adjacency activation mechanism to obtain the effective voxels for reconstruction and a fast lookup table mechanism to obtain the set of face arrays and vertex coordinates of the effective voxels for reconstruction. This method is directly used for the reconstruction of the outer surface of the three-dimensional graphics, which significantly reduces the amount of computation, simplifies the reconstruction process, improves computational efficiency, and shortens the computation time. It effectively solves the technical problems of low computational efficiency and low three-dimensional surface reconstruction efficiency of traditional methods. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a schematic diagram of the three-dimensional model surface reconstruction method according to the embodiment;

[0045] Figure 2 This is a schematic diagram of a voxel cube according to an embodiment;

[0046] Figure 3 This is a schematic diagram of the connection structure of adjacent voxels according to an embodiment.

[0047] Figure 4 This is a schematic diagram showing the arrangement of vertex numbers of voxels according to an embodiment. Detailed Implementation

[0048] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0049] Reference Figure 1 , Figure 2 , Figure 3 This invention discloses a method for reconstructing the surface of a three-dimensional model, comprising:

[0050] S1. Construct a general cube reconstruction index table, which includes all combinations of the six faces of the cube participating in reconstruction and the corresponding face reconstruction mask, vertex reconstruction mask, and vertex index. The face reconstruction mask is a six-bit binary number, where a bit with a value of 1 represents that the corresponding face participates in reconstruction, and a bit with a value of 0 represents that the corresponding face does not participate in reconstruction. The vertex reconstruction mask is an eight-bit binary number, where a bit with a value of 1 represents that the corresponding vertex participates in reconstruction, and a bit with a value of 0 represents that the corresponding vertex does not participate in reconstruction.

[0051] S2. Obtain three-dimensional volume data, which includes multiple voxels; each voxel has a defined three-dimensional index, spatial size, and binary state; the spatial size of each voxel is the same, but it can also be different; the binary state includes active state and inactive state.

[0052] S3. Obtain the patch reconstruction mask of the voxel in the active state based on the binary state of each voxel directly adjacent to each voxel in the active state. When the value is greater than 0, the voxel is a valid voxel for reconstruction. Obtain the set of valid voxels C and the corresponding set of patch reconstruction masks B.

[0053] S4. Based on the set of effective voxels for reconstruction C, the set of face reconstruction masks B, and the general cube reconstruction index table, obtain the set of face arrays and vertex coordinates for reconstruction; the face array is the global index of the four vertices that make up the reconstructed face.

[0054] S5. Construct a reconstructed surface model based on the set of face arrays and vertex coordinates.

[0055] S1 is a one-time construction used in the process of reconstructing the surfaces of various 3D models during 3D image updates; S2 to S5 are repeated during 3D image updates.

[0056] The three-dimensional model surface reconstruction method of the present invention predefines the combination of the six faces of a cube participating in the reconstruction and generates a general cube reconstruction index table with corresponding topological structures. It also uses an adjacency activation mechanism to obtain the effective voxels for reconstruction and a fast table lookup mechanism to obtain the set of face arrays and vertex coordinates of the effective voxels for reconstruction. This method is directly used for the reconstruction of the outer surface of three-dimensional graphics, which significantly reduces the amount of computation, simplifies the reconstruction process, improves computational efficiency, and shortens the computation time. It effectively solves the technical problems of low computational efficiency and low three-dimensional surface reconstruction efficiency of traditional methods.

[0057] The specific process and principle of the three-dimensional model surface reconstruction method of the present invention will be described in detail below through specific embodiments.

[0058] In some specific embodiments, refer to Figure 1 , Figure 2 , Figure 3 Three-dimensional volume data has a defined three-dimensional dimension. ; , , These represent the number of voxels along the x-axis, y-axis, and z-axis, respectively; each voxel has a defined three-dimensional index. ; ; ; .

[0059] Define a global index for voxels:

[0060] ;

[0061] This is the global index value of the voxel.

[0062] 3D indexing of each vertex of a voxel Then, the vertices of the voxel are defined with global indices:

[0063] ;

[0064] The global index value of the voxel's vertex.

[0065] Then the body element direct adjacent voxels The global index values ​​are respectively , , , , , They respectively through , , Obtained by inputting the global index definition of the voxel.

[0066] The relative positions of adjacent voxels corresponding to each global index value are shown in Table 1 below.

[0067] Table 1 Global Linear Index of Neighboring Voxels

[0068]

[0069] The three-dimensional model surface reconstruction method in this embodiment defines a global index for voxels and obtains the global index of each directly adjacent voxel through the global index. It then obtains the data of each voxel stored continuously in memory through the global index, such as the binary state of each adjacent voxel. This simplifies the retrieval of data stored in the one-dimensional continuous space of the three-dimensional volume data in memory, improves the speed of obtaining information of directly adjacent voxels, and thus improves the efficiency of obtaining the effective set of voxels for reconstruction.

[0070] In some specific embodiments, refer to Figure 2The face reconstruction mask of the active voxel is calculated to determine whether it is a valid voxel for reconstruction, that is, to determine whether the voxel participates in the reconstruction of the three-dimensional surface model.

[0071] The patch reconstruction mask is a six-bit binary number. From the least significant bit to the most significant bit, each bit represents a patch in the x+ (right), x- (left), y+ (back), y- (front), z+ (up), and z- (down) directions, respectively. If a patch participates in the reconstruction, the corresponding bit is 1; otherwise, it is 0. That is, a bit with a value of 1 indicates that the corresponding patch participates in the reconstruction. When the voxel adjacent to the patch participating in the reconstruction is an inactive voxel, the corresponding patch is a patch on a three-dimensional surface, and its corresponding patch mask bit is 1.

[0072] Reference Figure 4 The bits from least significant to most significant represent vertices 0 to 7 of the cube. Similarly, the vertex reconstruction mask is an eight-bit binary number, where a bit with a value of 1 indicates that the corresponding vertex is involved in the reconstruction. When the face containing a vertex is involved in the reconstruction, the bits of the vertex reconstruction mask corresponding to its four vertices are 1.

[0073] The voxel patch reconstruction mask b is calculated as follows:

[0074] ;

[0075] in, The brackets represent Iverson; the value is 1 if the condition is true, and 0 otherwise.

[0076] This refers to the six directly adjacent voxels in the voxel's six directions. Represents the adjacent voxel in the d-th direction;

[0077] It represents the binary state of a voxel, with 1 for the active state and 0 for the inactive state.

[0078] The set of voxels participating in the 3D surface reconstruction is the effective set of voxels for reconstruction. The corresponding set of patch reconstruction masks is , The number of effective voxels involved in the reconstruction of the outer surface.

[0079] In some specific embodiments, when obtaining effective voxels for reconstruction, the space of the 3D volume data is divided into multiple spatial regions, and different spatial regions are processed in parallel using multi-threading. This effectively improves the utilization of computing resources, significantly increases computational efficiency, shortens computation time, and effectively solves the technical problems of low computational efficiency and long computation time in traditional methods.

[0080] In some specific embodiments, each voxel in the reconstructed effective voxel set is re-indexed globally. Its value is 0, 1, 2, ..., N-1; N is the number of reconstructed effective voxels in the reconstructed effective voxel set. The voxels involved in the outer surface reconstruction... Establish mapping for individual elements:

[0081] ;

[0082] Calculate the global index position for the reconstructed facets and vertices of each reconstructed effective voxel; that is, the position or number corresponding to the first reconstructed facet of the reconstructed effective voxel, and the position or number corresponding to the first reconstructed vertex of the reconstructed effective voxel, specifically:

[0083] , ;

[0084] In the formula, To reconstruct the effective voxel numbers, the values ​​are 0, 1, 2, ..., N-1; and These represent the number of faces and vertices involved in the reconstruction of voxels, respectively, with parameters being the face mask and vertex mask.

[0085] and The value can be obtained by adding the number of faces and vertices involved in the reconstruction to the general cube reconstruction index table, and then based on the effective voxels of the reconstruction. The corresponding face mask is obtained by looking up a table.

[0086] Final total number of reconstructed facets Total number of reconstructed vertices They are respectively:

[0087] , ;

[0088] Similarly, and They represent the patch mask respectively. The corresponding functions for the number of reconstructed faces and the number of reconstructed vertices for voxels have the face mask and vertex mask of the effective voxels as parameters, respectively.

[0089] Similarly, and The value can be obtained by adding the number of faces and vertices involved in the reconstruction to the general cube reconstruction index table, and then based on the effective voxels of the reconstruction. The corresponding face mask is obtained by looking up a table.

[0090] The position or number of the first reconstructed vertex of the reconstructed effective voxel is used to obtain the global index of the vertex; the final total number of reconstructed patches Total number of reconstructed vertices This is to reserve storage space for storing the reconstructed surface model.

[0091] In some specific embodiments, the local index of each reconstructed vertex in the voxel is represented by a three-dimensional array; the first dimension is the patch combination number, with a value of 0 to 63; the second dimension is the patch number under the corresponding patch combination number, with a value of 0 to 6; and the third dimension is the vertex number corresponding to the patch number, with a value of 0 to 7.

[0092] Then, the global index of the reconstructed vertices of the effective voxels is:

[0093] ;

[0094] in, ; N represents the number of effective voxels for reconstruction. A function to index the vertices involved in the reconstruction of effective voxels, with a three-dimensional array as the parameter; This is the global indexing function for vertices. That is, the transformation function. Convert the vertex index local to the current voxel to the global vertex index.

[0095] The reconstructed patch array set is then:

[0096] ;

[0097] in, ; The three-dimensional surface reconstruction model includes Each quadrilateral patch; each patch array It consists of 4 vertex indices.

[0098] In some specific embodiments, refer to Figure 4 The vertex coordinates of a voxel are obtained from its 3D index, specifically:

[0099] Based on the three-dimensional index of voxels and the transformation matrix from discrete index coordinates to world coordinates Obtain the center coordinates of the voxel ;

[0100] Based on the spatial dimensions of voxels The coordinates of the eight vertices of the voxel obtained from the coordinates of point C are as follows: , , , , , , , ;

[0101] in,

[0102] This is a function for the coordinates of voxel vertices, whose parameter is the voxel vertex index;

[0103] , , , , , . Along the center point of the voxel The x-axis coordinate is offset by half a unit in the positive direction. along The x-axis coordinate is offset by half a unit in the negative direction. Along the center point of the voxel The y-axis coordinate is offset by half a unit length in the positive direction of the axis. along The y-axis coordinate is offset by half a unit in the negative direction. Along the center point of the voxel The z-axis coordinate is offset by half a unit length in the positive direction of the axis. along The z-axis coordinate is offset by half a unit length in the negative direction.

[0104] Specific voxels The mapping relationship of the coordinates of each vertex is shown in Table 2 below, which is the coordinate in the world coordinate system.

[0105] Table 2 Vertex Coordinate Expressions

[0106]

[0107] In some specific embodiments, the set of reconstructed vertex coordinates of the effective voxels is as follows:

[0108] ;

[0109] voxels The number of vertices involved in the outer surface reconstruction is Each vertex Coordinates are calculated using the following formula:

[0110] ;

[0111] In the formula, , for The value of each bit in binary form (0 or 1), i.e. ;function voxels The local vertex index is converted to the world coordinates of that vertex.

[0112] In some specific embodiments, the specific steps for obtaining the vertex coordinate set and the face array set are as follows:

[0113] parallel ;

[0114] Voxel acquisition ;

[0115] Calculate center coordinates ;

[0116] Generate coordinates of 8 vertices ;

[0117] Reconstruct the mask based on the vertices. Get the vertices you need to use; The local vertex index used is converted to the global vertex index;

[0118] Based on the vertex index list Generate an array of facets.

[0119] That is, the acquisition of reconstructed vertex coordinates and the construction of the face array are both executed in parallel using multi-threading, thereby improving reconstruction efficiency.

[0120] In some specific embodiments, an absolute tolerance is set. ; Obtain the distance between each reconstructed vertex; merge distances less than The vertices are used to optimize the 3D surface model.

[0121] In some specific embodiments, all quadrilateral patches in the three-dimensional surface model are decomposed into triangular patches to obtain a pure triangular mesh surface model.

[0122] A smoothing filter based on the window Sinc function is used to smooth the pure triangular mesh surface model to obtain the final smooth mesh model.

[0123] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0124] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0125] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0126] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0127] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0128] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for reconstructing the surface of a three-dimensional model, characterized in that, include: A general cube reconstruction index table is constructed, which includes all combinations of the six faces of the cube participating in reconstruction and the corresponding face reconstruction mask, vertex reconstruction mask, and vertex index; the face reconstruction mask is a six-bit binary number, where a bit with a value of 1 represents the corresponding face participating in reconstruction; the vertex reconstruction mask is an eight-bit binary number, where a bit with a value of 1 represents the corresponding vertex participating in reconstruction. Acquire three-dimensional volume data, which includes multiple voxels; each voxel has a defined three-dimensional index, binary state, and spatial size; the binary state includes an active state and an inactive state; The patch reconstruction mask is obtained based on the binary state of the adjacent voxels in the active state. When the value is greater than 0, the voxel is a valid voxel for reconstruction. The set of valid voxels for reconstruction C and the corresponding set of patch reconstruction masks B are obtained. The set of effective voxels for reconstruction C, the set of face reconstruction masks B, and the general cube reconstruction index table are used to obtain the set of face arrays and the set of vertex coordinates for reconstruction; the face array is the global index of the four vertices that make up the reconstructed face. Construct a reconstructed surface model based on the set of face arrays and the set of vertex coordinates; The set of facet arrays participating in reconstruction, obtained based on the reconstructed effective voxel set, the facet reconstruction mask set, and the general cube reconstruction index table, includes: Each of the reconstructed effective voxels in the reconstructed effective voxel set is renumbered and indexed. ; Obtain the patch offset of each of the reconstructed effective voxels. and vertex offset : , ； in, The function is the number of patches involved in the reconstruction of the effective voxels, and its parameter is the patch reconstruction mask; The function is the number of vertices participating in the reconstruction of the effective voxels, and its parameter is the vertex reconstruction mask; Obtain the set of face arrays: ； in, ; N represents the number of effective voxels in the reconstruction. The function is the index of each vertex participating in the reconstruction of the effective voxel, with the parameter being the three-dimensional array; , This is the global indexing function for vertices; The set of vertex coordinates for reconstruction, obtained based on the set of effective voxels, the set of face reconstruction masks, and the general cube reconstruction index table, includes: voxels The number of vertices involved in the outer surface reconstruction is Each vertex The coordinates are calculated using the following formula: ; In the formula, , for The binary representation of each bit is either 0 or 1, and the function... voxels The local vertex index is converted to the world coordinates of that vertex; The set of vertex coordinates is: 。 2. The three-dimensional model surface reconstruction method according to claim 1, characterized in that, When acquiring the reconstructed effective voxels, the space of the three-dimensional volume data is divided into multiple spatial regions, and the reconstructed effective voxels of different spatial regions are acquired in parallel using multi-threading.

3. The three-dimensional model surface reconstruction method according to claim 1, characterized in that, The adjacent voxels are implemented through a global index of each voxel, including: The three-dimensional volume data has a defined three-dimensional dimension. The three-dimensional index of each voxel is: ; , , These represent the number of voxels in the x-axis, y-axis, and z-axis directions, respectively. ; ; ; The global index of the voxel is: ; The global indices of each adjacent voxel are as follows: , , , , , .

4. The three-dimensional model surface reconstruction method according to claim 3, characterized in that, In the general cube reconstruction index table, the vertex indices participating in the reconstruction are represented by a three-dimensional array; the first dimension is the sequence number of the face combination; the second dimension is the face number under the face combination sequence number; and the third dimension is the vertex number corresponding to the face number.

5. The three-dimensional model surface reconstruction method according to claim 4, characterized in that, The vertex coordinates of each effective voxel are obtained based on the voxel's 3D index and spatial dimensions, including: According to the three-dimensional index of the voxel and the transformation matrix from discrete index coordinates to world coordinates Obtain the center point coordinates of the voxel ; ; Based on the spatial dimensions of the voxel and the coordinates of the center point The coordinates of the eight vertices of the voxel are obtained as follows: , , , , , , , ; in, This is a function for the coordinates of voxel vertices, whose parameter is the voxel vertex index; , , , , , 。 6. The three-dimensional model surface reconstruction method according to claim 5, characterized in that, The construction of the face array and the acquisition of vertex coordinates are both performed using multi-threading.

7. The method for reconstructing the surface of a three-dimensional model according to any one of claims 1 to 6, characterized in that, Setting absolute tolerance Merging distance is less than The vertices are used to optimize the reconstructed surface model.

8. The three-dimensional model surface reconstruction method according to claim 7, characterized in that, All quadrilateral patches in the reconstructed surface model are decomposed into triangular patches to obtain a pure triangular mesh surface model. The pure triangular mesh surface model is smoothed using a smoothing filter based on the window Sinc function to obtain the final smooth mesh model.

Images