CN114219913A - Section sealing method and device for three-dimensional model of empty area - Google Patents

Section sealing method and device for three-dimensional model of empty area Download PDF

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CN114219913A
CN114219913A CN202111393354.3A CN202111393354A CN114219913A CN 114219913 A CN114219913 A CN 114219913A CN 202111393354 A CN202111393354 A CN 202111393354A CN 114219913 A CN114219913 A CN 114219913A
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contour line
point
line
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dimensional model
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林远华
杨桂远
李先敬
曾春茂
冯建华
钟水平
苏红军
陈涛
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Fankou Lead Zinc Mine of Shenzhen Zhongjin Lingnan Nonfemet Co Ltd
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Fankou Lead Zinc Mine of Shenzhen Zhongjin Lingnan Nonfemet Co Ltd
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Abstract

The embodiment of the application is suitable for the technical field of mining, and provides a section sealing method and device of a three-dimensional model of an empty area, wherein the method comprises the following steps: obtaining a contour line generated by sectioning a three-dimensional model of a vacant area by a sectioning plane, wherein the three-dimensional model of the vacant area is a solid triangular mesh model and comprises a plurality of triangles in a triangular mesh form; cutting off the convex area of the contour line to obtain a target contour line, wherein the target contour line is a polygonal contour line; performing internal interpolation on the target contour line to generate a plurality of regular triangular meshes in the target contour line; extracting regular triangle mesh boundaries formed by a plurality of regular triangle meshes; and closing the section of the empty area three-dimensional model based on the regular triangle mesh boundary and the target contour line. By adopting the method, the section of the three-dimensional model of the empty area can be accurately sealed, and the integrity and uniformity of the generated new model area are ensured.

Description

Section sealing method and device for three-dimensional model of empty area
Technical Field
The embodiment of the application belongs to the technical field of mining, and particularly relates to a section sealing method and device of a three-dimensional model of an empty area.
Background
A goaf formed by underground mining of mineral resources is one of main disaster sources endangering safety production of mines, detection of the goaf is effectively implemented, spatial characteristic information such as three-dimensional shape, spatial position, actual boundary and volume size of the goaf is accurately obtained, and the goaf detection method is an important basic work for analyzing, predicting and monitoring disasters caused by the goaf and improving mining design and safety management levels.
In the prior art, a digital tool can be adopted to detect the empty area and construct a three-dimensional model of the empty area. Sectioning the three-dimensional model of the dead zone can provide a basis for performing related mining design (such as pillar mining) and other works around the dead zone. In general, the cutting of the three-dimensional model of the empty region will form two parts of a positive region and a negative region, and in order to ensure the integrity of the newly generated model, the section of the model needs to be closed.
In the prior art, the method of cutting ears and inserting a central point is generally adopted to seal the section of the model. However, the above method easily generates a long narrow or self-intersecting model region.
Disclosure of Invention
In view of this, the embodiment of the present application provides a method and an apparatus for closing a section of a three-dimensional model of an empty area, so as to accurately close the section of the three-dimensional model of the empty area and ensure the integrity and uniformity of a generated new model area.
A first aspect of an embodiment of the present application provides a section sealing method for a three-dimensional model of an empty area, including:
obtaining a contour line generated by sectioning a three-dimensional model of a vacant area by a sectioning plane, wherein the three-dimensional model of the vacant area is a solid triangular mesh model and comprises a plurality of triangles in a triangular mesh form;
cutting off the convex area of the contour line to obtain a target contour line, wherein the target contour line is a polygonal contour line;
performing internal interpolation on the target contour line to generate a plurality of regular triangular meshes in the target contour line;
extracting regular triangle mesh boundaries formed by a plurality of regular triangle meshes;
and closing the section of the empty area three-dimensional model based on the regular triangle mesh boundary and the target contour line.
Optionally, the obtaining a contour line generated by sectioning the three-dimensional model of the void region by a sectioning plane includes:
acquiring an initial contour line from an intersection line container for storing intersection line segments between the sectioning plane and the plurality of triangles, wherein the initial contour line has a head point and a tail point;
and determining an adjacent intersection line segment of the initial contour line from the intersection line container, and updating a tail point of the initial contour line according to a target point of the adjacent intersection line segment until the contour line is generated, wherein the target point of the adjacent intersection line segment is one of a head point and a tail point of the adjacent intersection line segment, which is farther from the initial contour line.
Optionally, the determining the adjacent intersection segments of the initial contour line from the intersection container includes:
respectively calculating the distance between the head point and the tail point of each intersection line segment in the intersection line container and the tail point of the initial contour line;
and when the distances between the head point and the tail point of the intersection line segment and the tail point of the initial contour line are smaller than a preset distance threshold, determining the intersection line segment as an adjacent intersection line segment of the initial contour line.
Optionally, the cutting off the protruding region of the contour line to obtain a target contour line includes:
determining each salient point on the contour line;
and cutting off a triangle formed by each salient point and two adjacent end points to obtain the target contour line.
Optionally, the determining the respective bumps on the contour line includes:
aiming at any end point on the contour line, judging whether a connecting line between two end points adjacent to the end point is positioned in the contour line;
and if a connecting line between two end points adjacent to the end points is positioned in the contour line, judging that the end points are the salient points on the contour line.
Optionally, the performing the internal interpolation on the target contour line includes:
determining an interpolation main line and an interpolation distance, wherein the interpolation main line is a connecting line between two points with the maximum distance in the target contour line;
drawing an auxiliary line system comprising a plurality of auxiliary lines according to the interpolation interval, wherein the distance between any two adjacent auxiliary lines is equal to the interpolation interval, and each auxiliary line is rotated clockwise by 60 degrees and then is parallel to or coincided with the interpolation main line;
determining intersection points between the auxiliary lines and the target contour line;
inserting interpolation points equally spaced between two intersection points of the plurality of the auxiliary lines to obtain a plurality of regular triangle meshes.
Optionally, the closing the section of the empty area three-dimensional model based on the regular triangle mesh boundary and the target contour line includes:
aiming at any boundary point on the boundary of the regular triangle mesh, determining the adjacent point of the boundary point on the target contour line;
determining a point with the largest opening angle relative to the known edge as a third point of the target triangle by taking a connecting line between the boundary point and the adjacent point as the known edge, wherein the third point is a point on the boundary of the regular triangle or a point on the target contour line;
and repeatedly executing the step of determining a point with the largest opening angle relative to the known edge as a third point of the coil triangle by taking one edge of the target triangle as a new known edge so as to finish the closing of the section of the empty area three-dimensional model, wherein one edge of the target triangle is the edge which connects the mesh boundary of the regular triangle and the target contour line and contains the third point.
A second aspect of an embodiment of the present application provides a section sealing device for a three-dimensional model of an empty area, including:
the acquisition module is used for acquiring a contour line generated by sectioning a three-dimensional model of a vacant area by a sectioning plane, wherein the three-dimensional model of the vacant area is a solid triangular mesh model and comprises a plurality of triangles in a triangular mesh form;
the cutting module is used for cutting the convex area of the contour line to obtain a target contour line, and the target contour line is a polygonal contour line;
the interpolation module is used for carrying out internal interpolation on the target contour line so as to generate a plurality of regular triangle meshes in the target contour line;
the extraction module is used for extracting regular triangle mesh boundaries formed by a plurality of regular triangle meshes;
and the closing module is used for closing the section of the empty area three-dimensional model based on the regular triangle grid boundary and the target contour line.
A third aspect of embodiments of the present application provides a computer device, which includes a memory, a processor, and a computer program stored in the memory and executable on the processor, and the processor executes the computer program to implement the section closing method for the three-dimensional model of the empty area according to the first aspect.
A fourth aspect of embodiments of the present application provides a computer-readable storage medium, which stores a computer program, and the computer program, when executed by a processor, implements the section closing method for the three-dimensional model of the empty area according to the first aspect.
A fifth aspect of embodiments of the present application provides a computer program product, which when run on a computer, causes the computer to execute the section closing method for the three-dimensional model of the empty area according to the first aspect.
Compared with the prior art, the embodiment of the application has the following advantages:
according to the embodiment of the application, the contour line generated by sectioning the three-dimensional model of the empty area through the sectioning plane is obtained, the convex area of the contour line can be firstly cut off, the target contour line in a polygonal form is obtained, and the generation of a long and narrow triangle when the section is closed is effectively avoided. On the basis, internal interpolation can be carried out on the target contour line, and a plurality of regular triangle meshes are generated in the target contour line; by extracting the regular triangle mesh boundary formed by the regular triangle meshes, the section of the three-dimensional model of the empty area can be closed based on the regular triangle mesh boundary and the target contour line, and a perfect closed model section is obtained. By adopting the method provided by the embodiment of the application, the section of the model can be better closed, and a completely closed new goaf triangulation network model can be output.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings used in the embodiments or the description of the prior art will be briefly described below. It is obvious that the drawings in the following description are only some embodiments of the application, and that for a person skilled in the art, other drawings can be derived from them without inventive effort.
FIG. 1 is a schematic flow chart illustrating steps of a method for sealing a section of a three-dimensional model of a vacant area according to an embodiment of the present application;
FIG. 2 is a schematic flow chart illustrating steps of another method for sealing a section of a three-dimensional model of a vacant area according to an embodiment of the present application;
FIG. 3 is a schematic diagram illustrating an implementation manner of step S201 of a section closing method for a three-dimensional model of an empty area according to an embodiment of the present application;
FIG. 4 is a diagram illustrating a process for interpolating a target contour according to an embodiment of the present application;
FIG. 5 is a schematic diagram illustrating an effect of closing a cross section of a three-dimensional model of a dead space according to an embodiment of the present application;
FIG. 6 is a schematic illustration of a cross-sectional confinement arrangement for a three-dimensional model of a void according to an embodiment of the present application;
fig. 7 is a schematic structural diagram of a computer device according to an embodiment of the present application.
Detailed Description
In the following description, for purposes of explanation and not limitation, specific details are set forth, such as particular system structures, techniques, etc. in order to provide a thorough understanding of the embodiments of the present application. However, it will be apparent to one skilled in the art that the present application may be practiced in other embodiments that depart from these specific details. In other instances, detailed descriptions of well-known systems, devices, circuits, and methods are omitted so as not to obscure the description of the present application with unnecessary detail.
The technical solution of the present application will be described below by way of specific examples.
Referring to fig. 1, a schematic flow chart illustrating steps of a section closing method for a three-dimensional model of a vacant area according to an embodiment of the present application is shown, and the method may specifically include the following steps:
s101, obtaining a contour line generated by sectioning a three-dimensional model of an empty area by a sectioning plane, wherein the three-dimensional model of the empty area is a solid triangular mesh model and comprises a plurality of triangles in a triangular mesh form.
It should be noted that the method may be applied to a computer device, that is, the execution subject of the embodiment of the present application is a computer device.
In this embodiment, the three-dimensional model of the empty area may be a three-dimensional model constructed by acquiring detection data by performing on-site detection on the empty area with the aid of a digital tool and then using the detection data.
Illustratively, the vacant area may be detected using a vacant area monitoring system (CMS). CMS is mainly applicable to detection and precision measurement of underground stopes and empty areas, and the empty area is detected efficiently by adopting a CMS system, and the visual effect of detection results is good. The detection result can be directly used for calculating the volume and the roof area of the goaf, establishing a three-dimensional model of the goaf and the like, and further used for guiding related mining management and control processes such as goaf filling, pillar blasting design, stoping lean loss control, goaf stability analysis and the like.
Generally, the detection data obtained by detecting the empty region by using the CMS is three-dimensional point cloud data. According to the detection principle of CMS, these three-dimensional point cloud data can be stored in a circle. Therefore, when the three-dimensional model of the empty area is constructed based on the three-dimensional point cloud data, the topological relation among the point clouds can be established according to the storage rings, and therefore the entity triangular mesh model capable of accurately reflecting the form of the empty area is established. The entity triangular mesh model comprises a plurality of triangles in a triangular mesh form.
The sectioning plane can be a plane for sectioning the three-dimensional model of the empty area according to actual requirements. Because the empty area three-dimensional model comprises a plurality of triangles, the process of sectioning the empty area three-dimensional model by adopting the sectioning plane can be regarded as the process of sectioning the plurality of triangles by adopting the sectioning plane. There will be points of intersection with the cut plane in the cut triangle. The intersection points belonging to the same triangle can form an intersection line segment, and the intersection line segments corresponding to a plurality of triangles can be combined into a sectioning plane to section the three-dimensional model of the empty area to obtain a contour line.
Generally, a cutting plane is adopted to cut the three-dimensional model of the empty area to obtain a positive area triangular net and a negative area triangular net. In order to ensure the integrity of the newly generated triangular mesh model, the model section needs to be closed. Generally, the model section may be one or more irregular polygons, and the essence of closing the model section is to triangulate the inside of the irregular polygons on the plane, that is, to triangulate the polygons formed by the aforementioned contour lines.
S102, cutting off the convex area of the contour line to obtain a target contour line, wherein the target contour line is a polygonal contour line.
In the embodiment of the present application, for the outline in the form of a polygon, it may include a partially convex region. In order to ensure the smooth proceeding of the subsequent interpolation and avoid generating a very long and narrow triangle during the closing, the convex area on the contour line can be cut off to obtain the target contour line. It should be noted that the contour of the target obtained by cutting off the protruding region is still a polygon.
S103, carrying out internal interpolation on the target contour line so as to generate a plurality of regular triangle meshes in the target contour line.
In this embodiment, the internal interpolation of the target contour line may refer to determining a plurality of interpolation points in a polygon formed by the target contour line by means of interpolation, and the interpolation points may form a plurality of regular triangle meshes with each other.
In a specific implementation, an interpolation interval, that is, a side length of a regular triangle, may be determined first. Then, an initial interpolation point is determined in a polygon formed by the target contour line, and the initial interpolation point is used as a vertex of the regular triangle to respectively form a plurality of regular triangles with the interpolation distance as the side length towards the periphery.
In general, the starting interpolation point may be as close as possible to the central region of the polygon formed by the target contour line. According to the characteristics of regular triangles, the start interpolation point is used as a vertex of the regular triangle, and at most six regular triangles can be formed around the start interpolation point. After the six regular triangles are formed, one side of each regular triangle can be used as one side of another regular triangle, and the new regular triangle is formed by continuing to expand towards the periphery until a plurality of regular triangle meshes are formed in the area surrounded by the target contour line.
It should be noted that the boundaries of the regular triangular meshes finally formed in the region surrounded by the target contour line should not exceed the target contour line. That is, the respective vertices of the plurality of regular triangular meshes formed within the region surrounded by the target contour line should be located within the region surrounded by the target contour line.
And S104, extracting the regular triangle mesh boundary formed by the plurality of regular triangle meshes.
Since the regular triangles formed in the foregoing steps are all located within the range surrounded by the target contour line, the boundaries of the regular triangle mesh formed by these regular triangles should also be located within the range surrounded by the target contour line. The computer equipment can extract the corresponding regular triangle mesh boundary according to the finally formed regular triangle mesh.
And S105, closing the section of the empty area three-dimensional model based on the regular triangle mesh boundary and the target contour line.
In the embodiment of the present application, the polygon formed by the boundary of the regular triangle mesh and the object outline can be regarded as two independent non-intersecting coils. The computer equipment can seal the section of the three-dimensional model of the dead zone based on the regular triangle mesh boundary and the target contour line, so that a perfect sealed model section can be generated on the premise of avoiding generating a long and narrow triangle.
In the embodiment of the application, the contour line generated by sectioning the three-dimensional model of the empty area through the sectioning plane is obtained, the convex area of the contour line can be firstly cut off to obtain the target contour line in the polygonal form, and the generation of a long and narrow triangle when the section is closed is effectively avoided. On the basis, internal interpolation can be carried out on the target contour line, and a plurality of regular triangle meshes are generated in the target contour line; by extracting the regular triangle mesh boundary formed by the regular triangle meshes, the section of the three-dimensional model of the empty area can be closed based on the regular triangle mesh boundary and the target contour line, and a perfect closed model section is obtained. By adopting the method provided by the embodiment of the application, the section of the model can be better closed, and a completely closed new goaf triangulation network model can be output.
Referring to fig. 2, a schematic flow chart illustrating steps of another method for closing a section of a three-dimensional model of a vacant area according to an embodiment of the present application is shown, which may specifically include the following steps:
s201, obtaining a contour line generated by sectioning a three-dimensional model of an empty area by a sectioning plane, wherein the three-dimensional model of the empty area is a solid triangular mesh model and comprises a plurality of triangles in a triangular mesh form.
In the embodiment of the application, the three-dimensional model of the empty area may be an entity triangular mesh model which is constructed by performing on-site detection on the empty area to obtain detection data and then accurately reflecting the form of the empty area, and the entity triangular mesh model includes a plurality of triangles in a triangular mesh form. Therefore, the process of sectioning the three-dimensional model of the empty area by adopting the sectioning plane can be regarded as a process of sectioning a plurality of triangles by adopting the sectioning plane. The intersection points between the cutting plane and the respective triangle being cut may form a contour line.
In a possible implementation manner of the embodiment of the present application, as shown in fig. 3, obtaining a contour line generated by sectioning the three-dimensional model of the void area by a sectioning plane may specifically include the following substeps S2011-S2012:
and S2011, acquiring an initial contour line from an intersection line container for storing intersection line segments between the sectioning plane and the plurality of triangles, wherein the initial contour line has a head point and a tail point.
S2012, determining an adjacent intersection line segment of the initial contour line from the intersection line container, and updating a tail point of the initial contour line according to a target point of the adjacent intersection line segment until the contour line is generated, wherein the target point of the adjacent intersection line segment is one of a head point and a tail point of the adjacent intersection line segment, which is farther from the initial contour line.
In the embodiment of the application, when the cutting plane cuts the three-dimensional model of the empty area, two intersection points exist between each cut triangle and the cutting plane, a line segment connecting the two intersection points can be called as an intersection line segment of the cutting plane and the triangle, and the two intersection points are the head point and the tail point of the intersection line segment.
During the sectioning process, a cross line container can be used to store each cross line segment. Each intersection segment in the intersection container has a beginning point and an ending point. Because the storage of the intersection line segments in the intersection line container is disordered, the key point for accurately extracting the contour lines of the cross sections is to find the head-tail adjacent relation of the intersection line segments.
In specific implementation, an intersection line segment can be randomly selected from the intersection line container as an initial contour line, and then on the basis, other intersection line segments in the intersection line container are subjected to head-to-tail identification, so that a final contour line is constructed.
In the embodiment of the present application, for the initial contour line, the head point and the tail point thereof may be defined first. It should be noted that, for the extracted initial contour line, one intersection point may be randomly defined as a head point, and the corresponding other intersection point is a tail point. After the initial contour line is selected, the initial contour line may be deleted from the intersection container.
Then, all the intersecting line segments in the intersecting line container can be traversed, the adjacent intersecting line segments of the initial contour line are determined, and the tail points of the initial contour line are updated according to the target points of the adjacent intersecting line segments until the final contour line is generated. The target point of the adjacent intersection line segment is the point farther away from the initial contour line in the head point and the tail point of the adjacent intersection line segment.
In a specific implementation, the distances between the head point and the tail point of each intersection line segment in the intersection line container and the tail point of the initial contour line can be calculated respectively. When the distance between the head point and the tail point of a certain intersection line segment and the distance between the tail point of the initial contour line segment and the tail point of the initial contour line segment are both smaller than a preset distance threshold, the intersection line segment can be determined to be an adjacent intersection line segment of the initial contour line segment. The distance threshold can be determined according to actual needs, and in general, the distance threshold can be 10-6。
In the embodiment of the present application, the end point of the initial contour line is updated according to the target point of the adjacent intersection line segment, that is, the target point of the adjacent intersection line segment is connected with the end point of the initial contour line, the line segment formed after the connection is used as the updated initial contour line, and the target point is used as the end point of the updated initial contour line. At the same time, the adjacent intersection segment should be deleted from the intersection container.
The above steps may then be repeated continuously, continually updating the initial contour line until a closed contour line is generated. It is to be noted that whether or not a closed contour line is generated is judgedWhether the distance between the head point and the tail point of the generated contour line is smaller than the preset distance threshold value or not can be calculated. For example, it is judged whether the distance between the head point and the tail point is less than 10-6If so, it can be considered that a closed contour line has been generated currently.
S202, determining all salient points on the contour line.
In the embodiments of the present application, the salient points on the contour lines may refer to those points that cause the polygons formed by the contour lines to be convex polygons.
In a possible implementation manner of the embodiment of the present application, in order to determine each bump on the contour line, it may be determined whether a connection line between two end points adjacent to any end point on the contour line is located inside the contour line. If the connecting line between two end points adjacent to the end point is positioned in the contour line, the end point can be judged to be a convex point on the contour line; otherwise, the terminal is not a bump.
Illustratively, inside the polygon formed by the contour lines, B can be considered as a bump assuming that the connecting line between the ACs is located inside the polygon for any adjacent three point A, B, C.
S203, cutting off a triangle formed by each convex point and two adjacent end points to obtain the target contour line, wherein the target contour line is a polygonal contour line.
In the embodiment of the present application, a triangle formed by each protruding point and two adjacent end points can be cut off to avoid a long and narrow triangle from being generated when the cross section is subsequently closed.
Illustratively, for any adjacent three points A, B, C, if point B is a bump, triangle ABC can be cut away.
S204, determining an interpolation main line and an interpolation distance, wherein the interpolation main line is a connecting line between two points with the largest distance in the target contour line.
In the embodiment of the present application, in order to generate a plurality of regular triangles in the target contour line by means of interpolation, an interpolation main line and an interpolation interval may be determined first. The interpolation main line is a connection line between two points with the maximum distance in the target contour line, and the interpolation distance is the side length of the generated regular triangles. In general, 1 to 5 times of the average value of the side lengths of the respective sides of the polygon formed by the object contour line may be used as the interpolation distance.
Fig. 4 is a schematic diagram illustrating a process of interpolating a target contour line according to an embodiment of the present application. In fig. 4 (a), the regions S1 and S2 are the cut-out convex regions, and the interpolation main line is a connection line between two points at the maximum distance on the target contour line after the cut-out convex regions, that is, the line segment AB in fig. 4 (a).
S205, drawing an auxiliary line system comprising a plurality of auxiliary lines according to the interpolation interval, wherein the distance between any two adjacent auxiliary lines is equal to the interpolation interval, and each auxiliary line is rotated clockwise by 60 degrees and then is parallel to or coincided with the interpolation main line.
As shown in fig. 4 (a), a series of straight lines may be obtained by rotating counterclockwise by 60 degrees with reference to the main line, that is, the auxiliary line system, including l as shown in fig. 4 (a)-2、l-1、l0、l1、l2、l3、l4A wire, etc. And the distance between two adjacent auxiliary lines is equal to the interpolation distance. For example, |1、l2The distance between is equal to the interpolation distance. Each auxiliary line is rotated by 60 degrees clockwise and then is parallel to or coincided with the interpolation main line. Specifically, if each auxiliary line is rotated by 60 degrees clockwise with a point where the auxiliary line intersects the main line as an axis, the obtained line segment should coincide with the main line; if each auxiliary line is rotated clockwise by 60 degrees with other points as axes, the resulting line segment should be parallel to the main line.
S206, determining the intersection points between the auxiliary lines and the target contour line; interpolation points are inserted at equal intervals between two intersection points of the plurality of the auxiliary lines.
After obtaining the plurality of auxiliary lines, part of the auxiliary lines are necessarily intersected with the target contour line. For example, in (a) in FIG. 4,/-2、l-1、l0、l1、l2、l3、l4The auxiliary lines are all intersected with the target contour line。
In the embodiment of the present application, for a secondary line intersecting with an object contour line, interpolation points may be inserted at equal intervals between two intersection points of the secondary line. Based on the interpolation points inserted on the respective secondary lines, a plurality of regular triangle meshes as shown in (b) in fig. 4 can be obtained.
And S207, extracting the regular triangle mesh boundary formed by the regular triangle meshes.
In the embodiment of the application, after the regular triangle mesh is generated, the boundary of the regular triangle mesh can be extracted by sequentially searching clockwise. The equilateral triangular mesh boundaries and outline polygons can be viewed as two independent non-intersecting coils.
As shown in fig. 4 (b), the contour polygon of the coil 1 is a boundary of a polygon formed by the object contour line, and the contour polygon of the coil 2 is a boundary of a regular triangle mesh formed by a plurality of regular triangle meshes.
And S208, closing the section of the empty area three-dimensional model based on the regular triangle mesh boundary and the target contour line.
In the embodiment of the application, a maximum opening angle triangulation algorithm can be adopted to realize triangulation between the coils, and a point with the largest opening angle relative to a known edge is searched from adjacent points of the two coils to serve as a third point of a triangle, wherein the known edge is a step-by-step advancing edge connected between the two coils.
In a specific implementation, for any boundary point on the boundary of the aligned triangle mesh, the neighboring point of the boundary point on the target contour line may be determined. Then, by taking the connecting line between the boundary point and the adjacent point as a known edge, a point with the largest opening angle relative to the known edge is determined as a third point of the target triangle, and the third point can be a point on the boundary of the regular triangle mesh or a point on the target contour line. Thus, based on the boundary points, neighboring points, and the third point, a target triangle can be constructed. Then, one side of the target triangle can be taken as a new known side, and the step of determining the point with the largest opening angle relative to the known side as the third point of the target triangle is repeatedly executed, so as to complete the closing of the section of the empty area three-dimensional model. One side of the target triangle is a side connecting the mesh boundary of the regular triangle and the target contour line and including a third point. As shown in fig. 5, it is a schematic view showing the effect of closing the cross section of the three-dimensional model of the empty space according to the above method. As can be seen from FIG. 5, the section of the model is closed by adopting the scheme, so that a high-quality section can be obtained, and the contour line is accurate and details are not lost. Compared with the situation that more long and narrow triangles are easily generated when the cross section is closed by adopting a single ear cutting algorithm and other modes in the prior art, the triangular meshes on the cross section obtained by adopting the method provided by the embodiment of the application are very uniform and regular.
It should be noted that, the sequence numbers of the steps in the foregoing embodiments do not mean the execution sequence, and the execution sequence of each process should be determined by the function and the inherent logic of the process, and should not constitute any limitation on the implementation process of the embodiments of the present application.
Referring to fig. 6, a schematic diagram of a section closing device of a three-dimensional model of a vacant area according to an embodiment of the present application is shown, and specifically may include an obtaining module 601, a removing module 602, an interpolating module 603, an extracting module 604, and a closing module 605, where:
an obtaining module 601, configured to obtain a contour line generated by sectioning a three-dimensional model of a void area by a sectioning plane, where the three-dimensional model of the void area is a solid triangular mesh model and includes a plurality of triangles in a triangular mesh form;
a removing module 602, configured to remove the protruding region of the contour line to obtain a target contour line, where the target contour line is a polygonal contour line;
an interpolation module 603, configured to perform internal interpolation on the target contour line to generate a plurality of regular triangle meshes in the target contour line;
an extracting module 604, configured to extract a regular triangle mesh boundary formed by a plurality of regular triangle meshes;
and a closing module 605, configured to close the section of the empty area three-dimensional model based on the regular triangle mesh boundary and the target contour line.
In this embodiment of the application, the obtaining module 601 may be specifically configured to: acquiring an initial contour line from an intersection line container for storing intersection line segments between the sectioning plane and the plurality of triangles, wherein the initial contour line has a head point and a tail point; and determining an adjacent intersection line segment of the initial contour line from the intersection line container, and updating a tail point of the initial contour line according to a target point of the adjacent intersection line segment until the contour line is generated, wherein the target point of the adjacent intersection line segment is one of a head point and a tail point of the adjacent intersection line segment, which is farther from the initial contour line.
In this embodiment of the application, the obtaining module 601 may further be configured to: respectively calculating the distance between the head point and the tail point of each intersection line segment in the intersection line container and the tail point of the initial contour line; and when the distances between the head point and the tail point of the intersection line segment and the tail point of the initial contour line are smaller than a preset distance threshold, determining the intersection line segment as an adjacent intersection line segment of the initial contour line.
In this embodiment, the resection module 602 may be specifically configured to: determining each salient point on the contour line; and cutting off a triangle formed by each salient point and two adjacent end points to obtain the target contour line.
In an embodiment of the present application, the ablation module 602 may further be configured to: aiming at any end point on the contour line, judging whether a connecting line between two end points adjacent to the end point is positioned in the contour line; and if a connecting line between two end points adjacent to the end points is positioned in the contour line, judging that the end points are the salient points on the contour line.
In this embodiment, the interpolation module 603 may be specifically configured to: determining an interpolation main line and an interpolation distance, wherein the interpolation main line is a connecting line between two points with the maximum distance in the target contour line; drawing an auxiliary line system comprising a plurality of auxiliary lines according to the interpolation interval, wherein the distance between any two adjacent auxiliary lines is equal to the interpolation interval, and each auxiliary line is rotated clockwise by 60 degrees and then is parallel to or coincided with the interpolation main line; determining intersection points between the auxiliary lines and the target contour line; inserting interpolation points equally spaced between two intersection points of the plurality of the auxiliary lines to obtain a plurality of regular triangle meshes.
In this embodiment, the closing module 605 may be specifically configured to: aiming at any boundary point on the boundary of the regular triangle mesh, determining the adjacent point of the boundary point on the target contour line; determining a point with the largest opening angle relative to the known edge as a third point of the target triangle by taking a connecting line between the boundary point and the adjacent point as the known edge, wherein the third point is a point on the boundary of the regular triangle or a point on the target contour line; and repeatedly executing the step of determining a point with the largest opening angle relative to the known edge as a third point of the coil triangle by taking one edge of the target triangle as a new known edge so as to finish the closing of the section of the empty area three-dimensional model, wherein one edge of the target triangle is the edge which connects the mesh boundary of the regular triangle and the target contour line and contains the third point.
For the apparatus embodiment, since it is substantially similar to the method embodiment, it is described relatively simply, and reference may be made to the description of the method embodiment section for relevant points.
Referring to fig. 7, a schematic structural diagram of a computer device according to an embodiment of the present application is shown. As shown in fig. 7, the computer device 700 of the present embodiment includes: a processor 710, a memory 720, and a computer program 721 stored in said memory 720 and operable on said processor 710. The processor 710 executes the computer program 721 to implement the steps of the above-mentioned section sealing method for the three-dimensional model of the empty area, such as the steps S101 to S105 shown in fig. 1. Alternatively, the processor 710, when executing the computer program 721, implements the functions of each module/unit in each device embodiment described above, for example, the functions of the modules 601 to 605 shown in fig. 6.
Illustratively, the computer program 721 may be divided into one or more modules/units, which are stored in the memory 720 and executed by the processor 710 to accomplish the present application. The one or more modules/units may be a series of computer program instruction segments capable of performing certain functions, which may be used to describe the execution of the computer program 721 in the computer device 700. For example, the computer program 721 may be divided into an acquisition module, an ablation module, an interpolation module, an extraction module, and a sealing module, and each module may specifically function as follows:
the acquisition module is used for acquiring a contour line generated by sectioning a three-dimensional model of a vacant area by a sectioning plane, wherein the three-dimensional model of the vacant area is a solid triangular mesh model and comprises a plurality of triangles in a triangular mesh form;
the cutting module is used for cutting the convex area of the contour line to obtain a target contour line, and the target contour line is a polygonal contour line;
the interpolation module is used for carrying out internal interpolation on the target contour line so as to generate a plurality of regular triangle meshes in the target contour line;
the extraction module is used for extracting regular triangle mesh boundaries formed by a plurality of regular triangle meshes;
and the closing module is used for closing the section of the empty area three-dimensional model based on the regular triangle grid boundary and the target contour line.
The computer device 700 may be a desktop computer, a cloud server, or the like. The computer device 700 may include, but is not limited to, a processor 710, a memory 720. Those skilled in the art will appreciate that fig. 7 is only one example of a computer device 700 and is not intended to limit the computer device 700 and that computer device 700 may include more or less components than shown, or some components may be combined, or different components, e.g., computer device 700 may also include input output devices, network access devices, buses, etc.
The Processor 710 may be a Central Processing Unit (CPU), other general purpose Processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf Programmable Gate Array (FPGA) or other Programmable logic device, discrete Gate or transistor logic device, discrete hardware component, etc. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like.
The memory 720 may be an internal storage unit of the computer device 700, such as a hard disk or a memory of the computer device 700. The memory 720 may also be an external storage device of the computer device 700, such as a plug-in hard disk, a Smart Media Card (SMC), a Secure Digital (SD) Card, a Flash memory Card (Flash Card), etc. provided on the computer device 700. Further, the memory 720 may also include both internal storage units and external storage devices of the computer device 700. The memory 720 is used for storing the computer program 721 and other programs and data required by the computer device 700. The memory 720 may also be used to temporarily store data that has been output or is to be output.
The embodiment of the application also discloses a computer device, which comprises a memory, a processor and a computer program stored in the memory and capable of running on the processor, wherein the processor executes the computer program to realize the section closing method of the three-dimensional model of the empty area according to the foregoing embodiments.
The embodiment of the application also discloses a computer-readable storage medium, which stores a computer program, and the computer program is executed by a processor to implement the section closing method of the three-dimensional model of the empty area according to the foregoing embodiments.
The embodiment of the present application further discloses a computer program product, when the computer program product runs on a computer, the computer device is enabled to execute the section closing method of the three-dimensional model of the empty area according to the foregoing embodiments.
The above-mentioned embodiments are only used for illustrating the technical solutions of the present application, and not for limiting the same. Although the present application has been described in detail with reference to the foregoing embodiments, it should be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; such modifications and substitutions do not substantially depart from the spirit and scope of the embodiments of the present application and are intended to be included within the scope of the present application.

Claims (10)

1. A section closing method of a dead zone three-dimensional model is characterized by comprising the following steps:
obtaining a contour line generated by sectioning a three-dimensional model of a vacant area by a sectioning plane, wherein the three-dimensional model of the vacant area is a solid triangular mesh model and comprises a plurality of triangles in a triangular mesh form;
cutting off the convex area of the contour line to obtain a target contour line, wherein the target contour line is a polygonal contour line;
performing internal interpolation on the target contour line to generate a plurality of regular triangular meshes in the target contour line;
extracting regular triangle mesh boundaries formed by a plurality of regular triangle meshes;
and closing the section of the empty area three-dimensional model based on the regular triangle mesh boundary and the target contour line.
2. The method of claim 1, wherein the obtaining a contour line generated by sectioning the three-dimensional model of the void region by a sectioning plane comprises:
acquiring an initial contour line from an intersection line container for storing intersection line segments between the sectioning plane and the plurality of triangles, wherein the initial contour line has a head point and a tail point;
and determining an adjacent intersection line segment of the initial contour line from the intersection line container, and updating a tail point of the initial contour line according to a target point of the adjacent intersection line segment until the contour line is generated, wherein the target point of the adjacent intersection line segment is one of a head point and a tail point of the adjacent intersection line segment, which is farther from the initial contour line.
3. The method of claim 2, wherein said determining adjacent intersection segments of said initial contour line from said intersection container comprises:
respectively calculating the distance between the head point and the tail point of each intersection line segment in the intersection line container and the tail point of the initial contour line;
and when the distances between the head point and the tail point of the intersection line segment and the tail point of the initial contour line are smaller than a preset distance threshold, determining the intersection line segment as an adjacent intersection line segment of the initial contour line.
4. The method according to any one of claims 1-3, wherein said cutting out the protruding regions of the contour line to obtain the target contour line comprises:
determining each salient point on the contour line;
and cutting off a triangle formed by each salient point and two adjacent end points to obtain the target contour line.
5. The method of claim 4, wherein said determining each bump on said contour line comprises:
aiming at any end point on the contour line, judging whether a connecting line between two end points adjacent to the end point is positioned in the contour line;
and if a connecting line between two end points adjacent to the end points is positioned in the contour line, judging that the end points are the salient points on the contour line.
6. The method of any of claims 1-3 or 5, wherein said internally interpolating the target contour line comprises:
determining an interpolation main line and an interpolation distance, wherein the interpolation main line is a connecting line between two points with the maximum distance in the target contour line;
drawing an auxiliary line system comprising a plurality of auxiliary lines according to the interpolation interval, wherein the distance between any two adjacent auxiliary lines is equal to the interpolation interval, and each auxiliary line is rotated clockwise by 60 degrees and then is parallel to or coincided with the interpolation main line;
determining intersection points between the auxiliary lines and the target contour line;
inserting interpolation points equally spaced between two intersection points of the plurality of the auxiliary lines to obtain a plurality of regular triangle meshes.
7. The method of claim 6, wherein said closing the section of the empty area three-dimensional model based on the regular triangle mesh boundary and the target contour line comprises:
aiming at any boundary point on the boundary of the regular triangle mesh, determining the adjacent point of the boundary point on the target contour line;
determining a point with the largest opening angle relative to the known edge as a third point of the target triangle by taking a connecting line between the boundary point and the adjacent point as the known edge, wherein the third point is a point on the boundary of the regular triangle or a point on the target contour line;
and repeatedly executing the step of determining a point with the largest opening angle relative to the known edge as a third point of the coil triangle by taking one edge of the target triangle as a new known edge so as to finish the closing of the section of the empty area three-dimensional model, wherein one edge of the target triangle is the edge which connects the mesh boundary of the regular triangle and the target contour line and contains the third point.
8. A section closing device of a three-dimensional model of a dead zone is characterized by comprising:
the acquisition module is used for acquiring a contour line generated by sectioning a three-dimensional model of a vacant area by a sectioning plane, wherein the three-dimensional model of the vacant area is a solid triangular mesh model and comprises a plurality of triangles in a triangular mesh form;
the cutting module is used for cutting the convex area of the contour line to obtain a target contour line, and the target contour line is a polygonal contour line;
the interpolation module is used for carrying out internal interpolation on the target contour line so as to generate a plurality of regular triangle meshes in the target contour line;
the extraction module is used for extracting regular triangle mesh boundaries formed by a plurality of regular triangle meshes;
and the closing module is used for closing the section of the empty area three-dimensional model based on the regular triangle grid boundary and the target contour line.
9. A computer device comprising a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the processor implements the method for section closure of a three-dimensional model of a vacant area according to any one of claims 1 to 7 when executing the computer program.
10. A computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor, implements the section sealing method for the three-dimensional model of the empty area according to any one of claims 1 to 7.
CN202111393354.3A 2021-11-23 2021-11-23 Section sealing method and device for three-dimensional model of empty area Pending CN114219913A (en)

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Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
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