Construction method of cocoon type space grid body and related device

Abstract

The embodiment of the invention provides a cocoon type space grid body construction method and a related device, and the method comprises the steps: obtaining a basic three-dimensional digital model of a shot target, and constructing a space detection grid body surrounding the basic three-dimensional digital model. Setting a spherical detector in a preset radius range at each target vertex of the space detection grid body, obtaining the number of collision points of each spherical detector and the basic three-dimensional digital model, and if the number of the collision points is 1, obtaining the sphere center position coordinates of the spherical detector and the connecting line space angle of the sphere center pointing to the collision points, according to the plurality of sphere center position coordinates and the plurality of connecting line space angles, a cocoon-type space grid body is constructed, and the distance between the finally obtained cocoon-type space grid body and the basic three-dimensional digital model meets a preset radius range, that is, the difference between the cocoon-type space grid body and the outer contour feature of the shot target is small; therefore, the modeling precision of performing accurate three-dimensional modeling on the shooting target by using the cocoon-type space grid body is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of high-precision tilt mapping and the field of aerial modeling, and in particular to a cocoon-type space grid construction method and related device. BACKGROUND

[0002] Tilt photography and aerial modeling is a technology for quickly and extensively obtaining a three-dimensional model of a geographic information carrying a photographed target using a camera payload and an observation platform. The camera payload and the observation platform can be a camera-carrying unmanned aerial vehicle. The unmanned aerial vehicle performs planar maneuvering in the air to collect images of the photographed target for three-dimensional modeling. However, this planar maneuvering for photographing the photographed target is sufficient for the information in the orthographic plane dimension, but insufficient for the information in other dimensions, which results in low modeling completeness and modeling accuracy when the photographed target is subsequently modeled three-dimensionally.

[0003] Currently, a low-fineness base three-dimensional digital model (i.e., a coarse model) of the photographed target can be loaded in a computer virtual space, and one or more maneuvering surfaces can be manually constructed on the basis of the coarse model to obtain a grid body that conforms to the contour features of the photographed target. Then, the camera payload and the observation platform collect images of the photographed target according to the grid body. Although the above-described method of forming a grid body by using a maneuvering surface can improve the modeling completeness when the photographed target is precisely three-dimensionally modeled, the maneuvering surface is manually constructed, which results in poor matching between the maneuvering surface and the contour features of the photographed target, and thus the grid body obtained by fitting the maneuvering surface has a large difference from the contour features of the photographed target, which finally results in problems in the modeling accuracy when the photographed target is precisely three-dimensionally modeled. SUMMARY

[0004] Therefore, the present application aims to provide a cocoon-type space grid construction method and related device, which can form a cocoon-type space grid that has a small difference from the contour features of the photographed target and completely covers the photographed target, so as to improve the modeling accuracy and completeness when the photographed target is precisely three-dimensionally modeled.

[0005] To achieve the above-mentioned purpose, the present application has the following technical solutions.

[0006] The present application provides a cocoon-type space grid construction method, which comprises the following steps:

[0007] obtaining a base three-dimensional digital model of a photographed target;

[0008] constructing a space exploration grid body that surrounds the base three-dimensional digital model, wherein the space exploration grid body comprises a plurality of micro-unit grid bodies, and each micro-unit grid body comprises a plurality of target vertices;

[0009] setting a spherical detector with a preset radius range at each of the target vertexes, obtaining a number of collision points of each of the spherical detector and the basic three-dimensional digital model, the collision points including intersection points and tangent points;

[0010] if the number of collision points of each of the spherical detector and the basic three-dimensional digital model is one, obtaining a spherical center position coordinate of the spherical detector and a spatial angle of a line connecting the spherical center and the collision point;

[0011] constructing a cocoon type spatial grid according to the plurality of spherical center position coordinates and the plurality of spatial angles of the line, a distance between the cocoon type spatial grid and the basic three-dimensional digital model satisfying the preset radius range.

[0012] Optionally, the method further comprises:

[0013] determining a connection relationship of the plurality of spherical center position coordinates according to the plurality of spatial angles of the line;

[0014] connecting the plurality of spherical center position coordinates to form the cocoon type spatial grid according to the connection relationship.

[0015] Optionally, the method further comprises:

[0016] a camera load and an observation platform shoot the photographed target using the cocoon type spatial grid, a position of the camera load and the observation platform being the spherical center position coordinate, and an angle of the camera load and the observation platform towards the photographed target being the spatial angle of the line.

[0017] Optionally, the method further comprises: moving each of the model vertexes of the basic three-dimensional digital model by a preset distance along a normal direction corresponding to each of the model vertexes to obtain a plurality of first vertexes;

[0018] connecting adjacent first vertexes to obtain a plurality of lines with different lengths, and equally dividing the plurality of lines by the line with the minimum length to obtain a plurality of second vertexes with equal intervals;

[0019] screening the plurality of target vertexes using the second vertexes;

[0020] the method further comprises:

[0021] setting the spherical detector with the preset radius range at the target vertexes with a distance from the second vertexes within a limited interval.

[0022] Optionally, the method further comprises:

[0023] According to an axial point of the basic three-dimensional digital model, the basic three-dimensional digital model is enlarged by a preset ratio to obtain a plurality of third vertices, a plurality of connecting lines of different lengths are obtained by connecting adjacent third vertices, and the plurality of connecting lines are equally divided by a connecting line of a minimum length to obtain a plurality of fourth vertices at equal intervals;

[0024] The fourth vertices are used to screen the plurality of target vertices;

[0025] The ball-shaped detector with a preset radius range is arranged at each target vertex.

[0026] The ball-shaped detector with a preset radius range is arranged at the target vertex having a distance from the fourth vertex within a limited range.

[0027] Optionally, the connecting line space angle includes a yaw angle, a pitch angle and a roll angle, the plurality of micro-unit grid bodies are cuboids of the same size, and a shooting density of shooting by using the cocoon-type space grid body is determined according to the size of the cuboid.

[0028] The application provides a construction device of a cocoon-type space grid body, which comprises:

[0029] A first acquisition unit is configured to acquire a basic three-dimensional digital model of a photographed target.

[0030] A first construction unit is configured to construct a space detection grid body surrounding the basic three-dimensional digital model, wherein the space detection grid body comprises a plurality of micro-unit grid bodies, and the micro-unit grid bodies comprise a plurality of target vertices.

[0031] A collision unit is configured to arrange a ball-shaped detector with a preset radius range at each target vertex, acquire a number of collision points between each ball-shaped detector and the basic three-dimensional digital model, and the collision points include intersection points and tangent points.

[0032] A second acquisition unit is configured to acquire a ball center position coordinate of the ball-shaped detector and a connecting line space angle of a connecting line from the ball center to the collision point if the number of collision points between the ball-shaped detector and the basic three-dimensional digital model is 1.

[0033] A second construction unit is configured to construct a cocoon-type space grid body according to a plurality of ball center position coordinates and a plurality of connecting line space angles, and a distance between the cocoon-type space grid body and the basic three-dimensional digital model satisfies the preset radius range.

[0034] The application provides a construction device of a cocoon-type space grid body, which comprises a processor and a memory.

[0035] The memory is configured to store instructions.

[0036] The processor is configured to execute the instructions in the memory to perform the method of any one of the preceding methods.

[0037] The present application provides a computer readable storage medium for storing a computer program, which, when executed on a computer device, causes the computer device to perform the method of any one of the preceding methods.

[0038] The present application provides a computer program product comprising a computer program, which, when executed on a computer device, causes the computer device to perform the method of any one of the preceding methods.

[0039] The present application provides a method for constructing a cocoon-shaped space grid, the method comprising: obtaining a basic three-dimensional digital model of a photographed target, constructing a space detection grid surrounding the basic three-dimensional digital model, the space detection grid comprising a plurality of micro-unit grids, each micro-unit grid comprising a plurality of target vertices, i.e., the basic three-dimensional digital model is surrounded by the plurality of micro-unit grids, thereby providing a basic grid structure for subsequent formation of the cocoon-shaped space grid. A spherical detector with a preset radius range is set at each target vertex, the number of collision points between each spherical detector and the basic three-dimensional digital model is obtained, the collision points comprising intersection points and tangent points, if the number of collision points between the spherical detector and the basic three-dimensional digital model is one, the position coordinates of the spherical center of the spherical detector and the spatial angle of the connecting line between the spherical center and the collision point are obtained, i.e., the spherical detector with the preset radius range can determine the position coordinates of the spherical center and the spatial angle of the connecting line with the outer contour feature of the photographed target having a fixed distance in the process of colliding with the basic three-dimensional digital model, thereby realizing subsequent construction of the cocoon-shaped space grid according to the plurality of position coordinates of the spherical center and the plurality of spatial angles of the connecting line, and the distance between the finally obtained cocoon-shaped space grid and the basic three-dimensional digital model satisfies the preset radius range, i.e., the cocoon-shaped space grid and the outer contour feature of the photographed target have a small difference and a high coverage, thereby improving the modeling accuracy and the modeling completeness when the photographed target is precisely three-dimensionally modeled by using the cocoon-shaped space grid. BRIEF DESCRIPTION OF DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and those skilled in the art can also obtain other drawings according to these drawings without any creative effort.

[0041] Figure 1 A schematic diagram showing the relationship between image shooting distance and accuracy is shown;

[0042] Figure 2A flow diagram of a cocoon type space grid body construction method provided by an embodiment of the present application is shown.

[0043] Figure 3 A basic three-dimensional digital model (rough model) provided by an embodiment of the present application is shown.

[0044] Figure 4 A space exploration grid body structure provided by an embodiment of the present application is shown.

[0045] Figure 5 A ball-shaped detector and basic three-dimensional digital model collision detection provided by an embodiment of the present application is shown.

[0046] Figures 6-8 A ball-shaped detector and basic three-dimensional digital model collision detection provided by an embodiment of the present application is shown.

[0047] Figures 9-11 A ball-shaped detector and basic three-dimensional digital model collision detection provided by an embodiment of the present application is shown.

[0048] Figures 12-14 A ball-shaped detector and basic three-dimensional digital model collision detection provided by an embodiment of the present application is shown.

[0049] Figure 15 A cocoon type space grid body structure provided by an embodiment of the present application is shown.

[0050] Figure 16 A cocoon type space grid body structure provided by an embodiment of the present application is shown.

[0051] Figure 17 A cocoon type space grid body structure provided by an embodiment of the present application is shown. DETAILED DESCRIPTION

[0052] In order to make the above objectives, features and advantages of the present application more apparent and comprehensible, the specific embodiments of the present application are described in detail below with reference to the accompanying drawings.

[0053] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the present application, therefore the present application is not limited to the specific embodiments disclosed below.

[0054] The application is described in detail in conjunction with the schematic diagram. In the detailed description of the embodiments of the application, the cross-sectional view of the device structure is partially enlarged without the general proportion for the convenience of description, and the schematic diagram is only an example, which should not limit the scope of protection of the application herein. In addition, the three-dimensional spatial dimensions of length, width and depth should be included in the actual manufacture.

[0055] Currently, image acquisition of the photographed target can be performed by using close-range photogrammetry technology, that is, by loading a basic three-dimensional digital model of the photographed target in a computer virtual space, manually operating to build one or more motorized planes, and the motorized planes can be composed of horizontal planes, vertical planes, inclined planes or annular planes, etc. A grid body conforming to the outer contour features of the photographed target can be obtained by fitting the motorized planes, and then the camera load and the observation platform perform image acquisition on the photographed target according to the grid body, that is, the camera load and the observation platform perform image acquisition on the photographed target according to the preset flight path of each motorized plane that meets the three-dimensional reconstruction overlap rate.

[0056] Although the above-mentioned method of forming a grid body by using a motorized plane can improve the modeling completeness when three-dimensional modeling of the photographed target is performed, the motorized plane is manually operated to build, and the building efficiency of the motorized plane is low, and there is a problem that the matching degree of the motorized plane and the outer contour features of the photographed target is poor, which further leads to a large difference between the grid body obtained by fitting the motorized plane and the outer contour features of the photographed target, and finally leads to a problem of modeling accuracy when precise three-dimensional modeling of the photographed target is performed.

[0057] In addition, when the camera load and the observation platform perform image acquisition on the photographed target, the distance between the center point of each image and the different positions of the photographed target is large, and the length is different. As shown in the reference Figure 1 That is, when the grid body is specifically used for image acquisition, the modeling accuracy of the photographed target in subsequent three-dimensional modeling is not uniform due to the large distance between the center point of the acquired image and the different positions of the photographed target.

[0058] Based on this, the application provides a construction method of a cocoon type space grid body, which comprises the following steps: The method comprises the following steps: obtaining a basic three-dimensional digital model of a photographed target, constructing a space detection grid body surrounding the basic three-dimensional digital model, the space detection grid body comprising a plurality of micro unit grid bodies, each micro unit grid body comprising a plurality of target vertices, i.e. the basic three-dimensional digital model is surrounded by the plurality of micro unit grid bodies, thereby providing a basic grid structure for subsequent formation of the cocoon type space grid body. A spherical detector with a preset radius range is arranged at each target vertex, the number of collision points between each spherical detector and the basic three-dimensional digital model is obtained, the collision points comprising intersection points and tangent points, if the number of collision points between the spherical detector and the basic three-dimensional digital model is one, the position coordinates of the spherical center of the spherical detector and the spatial angle of the connecting line from the spherical center to the collision point are obtained, i.e. in the process of collision with the basic three-dimensional digital model, the spherical detector with the preset radius range can determine the position coordinates of the spherical center with a fixed distance from the contour feature of the photographed target and the spatial angle of the connecting line, thereby realizing subsequent construction of the cocoon type space grid body according to the plurality of position coordinates of the spherical center and the plurality of spatial angles of the connecting line, and the distance between the finally obtained cocoon type space grid body and the basic three-dimensional digital model satisfies the preset radius range, i.e. the cocoon type space grid body is close to the contour feature of the photographed target, thereby improving the modeling accuracy when the photographed target is precisely modeled by using the cocoon type space grid body.

[0059] In order to better understand the technical solutions and technical effects of the application, specific embodiments will be described in detail below with reference to the drawings.

[0060] Reference Figure 2 As shown in the figure, the method comprises the following steps:

[0061] S101, obtaining a basic three-dimensional digital model of a photographed target.

[0062] In the embodiments of the application, the photographed target can be any geographical space or any object. Before actual image acquisition of the photographed target, a basic three-dimensional digital model of the photographed target can be obtained, the basic three-dimensional digital model being a coarse accuracy three-dimensional model matching the contour feature of the photographed target, i.e. a coarse model, which can be used as a basic model for subsequent construction of a cocoon type space grid body conforming to the contour feature of the photographed target. The basic three-dimensional digital model can be imported into a computer virtual three-dimensional space, so as to obtain the cocoon type space grid body in the computer virtual three-dimensional space.

[0063] As an example, the basic three-dimensional digital model of the photographed target can refer to the figure. Figure 3 As shown in the figure.

[0064] S102, constructing a space detection grid body surrounding the basic three-dimensional digital model.

[0065] In the embodiments of the present application, in order to form a cocoon-shaped space grid body matching the outer contour features of the photographed target, the cocoon-shaped space grid body can be calculated based on a space exploration grid body around the basic three-dimensional digital model of the photographed target, that is, a space exploration grid body surrounding the basic three-dimensional digital model can be constructed to provide a basic grid structure for subsequent formation of the cocoon-shaped space grid body.

[0066] Specifically, the space exploration grid body includes a plurality of micro-unit grid bodies, and each micro-unit grid body includes a plurality of target vertices. The connecting lines between adjacent target vertices form a micro-unit grid body. That is, a plurality of micro-unit grid bodies are stacked adjacent to each other to form a space exploration grid body, and the stacked plurality of micro-unit grid bodies surround the basic three-dimensional digital model.

[0067] The size of the plurality of micro-unit grid bodies can be defined by itself, and the plurality of micro-unit grid bodies have the same and consistent properties. For example, the plurality of micro-unit grid bodies are cuboids of the same size, and the length, width and height of the cuboids can be defined by themselves.

[0068] Since the space exploration grid body is a basic grid structure for subsequent formation of the cocoon-shaped space grid body, the size of the plurality of micro-unit grid bodies can affect the shooting density of the shooting using the cocoon-shaped space grid body. When the size of the micro-unit grid body is smaller, the shooting density of the shooting using the cocoon-shaped space grid body is higher, and vice versa. When the size of the micro-unit grid body is larger, the shooting density of the shooting using the cocoon-shaped space grid body is smaller.

[0069] As an example, referring to Figure 4 As shown, the plurality of micro-unit grid bodies are cuboids of the same size, and the shooting density of the shooting using the cocoon-shaped space grid body is determined according to the size of the cuboids, that is, according to the length, width and height of the cuboids.

[0070] S103, a spherical detector with a preset radius range is set at each target vertex, and the number of collision points of each spherical detector and the basic three-dimensional digital model is obtained.

[0071] S104, if the number of collision points of the spherical detector and the basic three-dimensional digital model is 1, the position coordinates of the center of the spherical detector and the spatial angle of the connecting line from the center to the collision point are obtained.

[0072] In the embodiments of the present application, it is considered that the more the cocoon-shaped space grid body matches the outer contour features of the photographed target, the higher the modeling accuracy of the accurate three-dimensional model obtained by the camera load and the observation platform when photographing with the cocoon-shaped space grid body. One of the factors affecting the matching of the cocoon-shaped space grid body and the outer contour features of the photographed target is the uniformity of the distance between the cocoon-shaped space grid body and the outer contour features of the photographed target, that is, the uniformity of the distance between the cocoon-shaped space grid body and the basic three-dimensional digital model. Therefore, in order to form a cocoon-shaped space grid body with uniform distance from the basic three-dimensional digital model, after forming a space detection grid body surrounding the basic three-dimensional digital model, a spherical detector with a preset radius range can be set at each target vertex of each micro-unit grid body, and the number of collision points of each spherical detector and the basic three-dimensional digital model is obtained, wherein the collision points include intersection points and tangent points, the center of the spherical detector is located at the position of the target vertex, and the preset radius range is the radius range of the spherical detector. That is, it is obtained whether each spherical detector and the basic three-dimensional digital model intersect, are tangent or do not contact at different target vertex positions. When intersecting, the number of collision points of each spherical detector and the basic three-dimensional digital model is greater than 1, when tangent, the number of collision points of each spherical detector and the basic three-dimensional digital model is equal to 1, and when not contacting, the number of collision points of each spherical detector and the basic three-dimensional digital model is 0.

[0073] In order to realize the uniform distance between the cocoon-shaped space grid body formed subsequently and the basic three-dimensional digital model, the target vertex can be screened by using the case that the number of collision points of each spherical detector and the basic three-dimensional digital model is equal to 1, because the number of collision points of each spherical detector and the basic three-dimensional digital model equal to 1 represents that each spherical detector and the basic three-dimensional digital model are tangent, so that the distance between each spherical detector and the basic three-dimensional digital model is equal to the radius of the spherical detector when tangent, and then the target vertex with a fixed distance from the basic three-dimensional digital model is determined by using the spherical detector. That is, the preset radius range of the spherical detector is the distance range between the cocoon-shaped space grid body and the basic three-dimensional digital model, that is, the target vertex with a fixed distance from the basic three-dimensional digital model in the space detection grid body is screened by using the preset radius range, and the position coordinates of these target vertices are the center coordinates of the spherical detector. Wherein, the preset radius range is 1-1.3 times of the preset radius, and the preset radius can be determined according to the actual shooting distance.

[0074] In view of the fact that in image acquisition of a photographed object, in addition to the shooting position affecting the image acquisition effect, the shooting angle also affects the image acquisition effect, and further affects the modeling accuracy of the subsequent precise three-dimensional model, therefore, in the collision detection using the spherical detector and the basic three-dimensional digital model, in addition to obtaining the spherical center position coordinates of the spherical detector according to the number of collision points being 1, the spatial angle of the line connecting the spherical center to the collision point can also be obtained, that is, the spatial angle of the line connecting the target vertex to the tangent point. When the number of collision points is 1, the spherical center position of the spherical detector is perpendicular to the collision point, that is, the spatial angle of the line is the shooting angle of the camera load and the observation platform shooting the photographed object. The spatial angle of the line includes the yaw angle (Yaw), the pitch angle (pitch) and the roll angle (roll).

[0075] As an example, referring to Figure 5 , a spherical detector with a preset radius range is set at the target vertex, the number of collision points of each spherical detector and the basic three-dimensional digital model is obtained, referring to Figures 6-8 , a cross-sectional view of the spherical detector and the basic three-dimensional digital model is shown. When the number of collision points of each spherical detector and the basic three-dimensional digital model is equal to 1, the spherical center position coordinates of the spherical detector and the spatial angle of the line connecting the spherical center to the collision point are obtained, referring to Figure 6 , when the number of collision points of each spherical detector and the basic three-dimensional digital model is greater than 1, which is equal to 2, referring to Figure 7 , at this time, the spherical center position coordinates of the spherical detector and the spatial angle of the line do not need to be obtained. When the number of collision points of each spherical detector and the basic three-dimensional digital model is equal to 0, referring to Figure 8 , at this time, the spherical center position coordinates of the spherical detector and the spatial angle of the line do not need to be obtained.

[0076] In the embodiments of the present application, since the space detection grid body includes a plurality of target vertices, in view of the efficiency problem of setting a spherical detector at each target vertex for collision detection, a plurality of target vertices that are more matched with the basic three-dimensional digital model can be screened out, and setting a spherical detector at these target vertices can greatly speed up the efficiency of collision detection. The plurality of target vertices that are more matched with the basic three-dimensional digital model have the following two possible implementation manners:

[0077] As a possible implementation manner, after the basic three-dimensional digital model is acquired, model vertices of the basic three-dimensional digital model are determined, and a normal direction corresponding to each model vertex is determined according to the model vertex of the basic three-dimensional model, wherein the normal direction of the model vertex is regarded as a direction of a normal vector of a tangent plane on which the model vertex is located on a curved surface of the basic three-dimensional digital model, and then each model vertex of the basic three-dimensional digital model is migrated along the normal direction corresponding to each model vertex by a preset distance to obtain a plurality of first vertices. A plurality of connecting lines of different lengths are obtained by connecting adjacent first vertices, and the plurality of connecting lines are equally divided in units of connecting lines of minimum length to obtain a plurality of second vertices at equal intervals. Subsequently, the plurality of target vertices can be screened by using the second vertices, and specifically, a spherical probe of a preset radius range can be set for a target vertex having a distance from the second vertex within a limited interval. Since the second vertex is matched with a vertex of the basic three-dimensional digital model, when the second vertex and the target vertex have a distance within the limited interval, the target vertex is also matched with a vertex of the basic three-dimensional digital model, and setting the spherical probe for the target vertex can greatly improve the efficiency of collision detection. The unit of the connecting line of minimum length is the preset distance, which can be determined according to the shooting density of the shooting by using the cocoon type space grid body.

[0078] As an example, referring to FIG. 1, Figure 9 the basic three-dimensional digital model is an octahedron, the normal direction corresponding to each model vertex is determined according to the model vertex of the basic three-dimensional model, referring to FIG. 2, Figure 10 each model vertex of the basic three-dimensional digital model is migrated along the normal direction by a preset distance to obtain a plurality of first vertices, a plurality of connecting lines of different lengths are obtained by connecting adjacent first vertices, referring to FIG. 3, Figure 11 the plurality of connecting lines are equally divided in units of connecting lines of minimum length to obtain a plurality of second vertices at equal intervals.

[0079] As another possible implementation manner, after the basic three-dimensional digital model is acquired, an axis point of the basic three-dimensional digital model is determined, the basic three-dimensional digital model is enlarged according to a preset ratio to obtain a plurality of third vertices, a plurality of connecting lines of different lengths are obtained by connecting adjacent third vertices, the plurality of connecting lines are equally divided in units of connecting lines of minimum length to obtain a plurality of fourth vertices at equal intervals. Subsequently, the plurality of target vertices can be screened by using the fourth vertices, and specifically, a spherical probe of a preset radius range can be set for a target vertex having a distance from the fourth vertex within a limited interval. Since the fourth vertex is matched with a vertex of the basic three-dimensional digital model, when the fourth vertex and the target vertex have a distance within the limited interval, the target vertex is also matched with a vertex of the basic three-dimensional digital model, and setting the spherical probe for the target vertex can greatly improve the efficiency of collision detection. The preset ratio can be determined according to the shooting density of the shooting by using the cocoon type space grid body.

[0080] As an example, reference is made to Figure 12 As shown in FIG. 8, the basic three-dimensional digital model is an octahedron, and the basic three-dimensional model is enlarged according to the axial point of the basic three-dimensional model by a preset ratio to obtain a plurality of third vertices. As shown in FIG. 9, the adjacent third vertices are connected to obtain a plurality of lines with different lengths, and the adjacent third vertices and the model vertices can also be connected. Figure 13 As shown in FIG. 10, the plurality of lines are equally divided in units of lines with the smallest length to obtain a plurality of fourth vertices with equal intervals. Figure 14

[0081] Therefore, a plurality of target vertices that are more matched with the basic three-dimensional digital model can be screened out by the above two methods, and the setting of the spherical probe at these target vertices can greatly improve the efficiency of collision detection. In actual application, other methods can also be used to screen out a plurality of target vertices that are more matched with the basic three-dimensional digital model, thereby improving the efficiency of collision detection and further improving the construction efficiency of the cocoon-type spatial grid.

[0082] S105, constructing a cocoon-type spatial grid according to the plurality of spherical center position coordinates and the plurality of line space angles.

[0083] In the embodiments of the present application, after obtaining the positions of the plurality of target vertices with a fixed distance from the basic three-dimensional digital model, i.e., after obtaining the plurality of spherical center position coordinates and the plurality of line space angles, the cocoon-type spatial grid can be constructed according to the plurality of spherical center position coordinates and the plurality of line space angles. Since the distance between the plurality of spherical center position coordinates and the basic three-dimensional digital model is the radius of the spherical probe, the radius of the spherical probe satisfies the preset radius range, i.e., the distance between the cocoon-type spatial grid and the basic three-dimensional digital model satisfies the preset radius range, thereby realizing that the cocoon-type spatial grid and the outer contour feature of the photographed target are less different, and thereby improving the modeling accuracy when the cocoon-type spatial grid is used to accurately model the photographed target.

[0084] Specifically, after obtaining the plurality of spherical center position coordinates and the plurality of line space angles, the connection relationship of the plurality of spherical center position coordinates can be determined according to the plurality of line space angles, and then the plurality of spherical center position coordinates are connected to form the cocoon-type spatial grid. This is because the plurality of line space angles can determine the spherical center position coordinates that are connected to each other, thereby avoiding the cocoon-type spatial grid formed after the connection of the spherical center position coordinates not matching the outer contour feature of the photographed target, for example, avoiding the line between the connected spherical center position coordinates penetrating the photographed target, and thereby further improving the accuracy of the formed cocoon-type spatial grid.

[0085] As an example, the cocoon-type spatial grid is constructed according to the plurality of spherical center position coordinates and the plurality of line space angles, reference is made to Figure 15 As shown in FIG. 11,​Figure 15 The cocoon-shaped spatial grid consists of multiple rectangles with tilted angles. The intersection of the diagonals of each rectangle is the coordinate of the sphere's center. The tilt angle of each rectangle is the spatial angle of the connecting line. Each rectangle represents the estimated shooting range, shooting position, and shooting angle of the camera payload and observation platform at that location.

[0086] In practical applications, cocoon-shaped spatial grids can completely cover the target being photographed, conforming to the target's outer contour features, as referenced. Figure 16 As shown, the thickness of the cocoon-shaped spatial grid or the preset radius of the spherical detector is the shooting distance. A fixed shooting distance is called equidistant shooting, which can achieve higher uniformity of image accuracy.

[0087] In the embodiments of this application, after the cocoon-shaped spatial mesh is calculated, the camera payload and observation platform can use the cocoon-shaped spatial mesh to photograph the target. The position of the camera in the camera payload and observation platform is the coordinate of the center of the sphere, and the angle of the camera in the camera payload and observation platform toward the target is the spatial angle of the line connecting them. That is, the cocoon-shaped spatial mesh can be used by the camera payload and observation platform to perform aerial photography operations, thereby forming a high-precision, accurate 3D model of the target.

[0088] Therefore, the cocoon-shaped spatial grid construction method provided in this application can automatically generate a cocoon-shaped spatial grid that equidistantly covers the target being photographed using a spatial detection grid and a spherical detector. This cocoon-shaped spatial grid can automatically adapt to the surface geometry of the target based on its elevation changes, greatly improving fitting efficiency and accuracy compared to manually fitting the outer contour features of the target. In other words, the cocoon-shaped spatial grid automatically generated by this application eliminates the need for manually constructing complex and rigid moving surfaces each time. Because it includes multiple sphere center coordinates and multiple connecting spatial angles, it can form a smoothly curved cocoon-shaped spatial grid that matches the target. The sphere center coordinates in the cocoon-shaped spatial grid represent the positions of the camera payload and the observation platform, i.e., the sphere center coordinates are aerial photography points. The distances between multiple aerial photography points and the target are always the same, resulting in extremely high uniformity of image accuracy. Since the angle of the camera towards the target is a connecting spatial angle, the shooting angles of the camera payload and the observation platform can adaptively change according to the surface undulations of the target. In addition, the movement of the camera payload and observation platform is restricted to the surface of the cocoon-shaped space grid, reducing the probability of collisions between the camera payload and the observation platform and thus increasing safety.

[0089] Based on the method for constructing a cocoon-shaped spatial mesh provided in the above embodiments, this application also provides a device for constructing a cocoon-shaped spatial mesh, see reference. Figure 17As shown, it is a structural schematic view of a cocoon type space grid body construction device provided by the embodiment of the application. The cocoon type space grid body construction device 200 provided by the embodiment of the application comprises:

[0090] A first acquisition unit 210 is configured to acquire a basic three-dimensional digital model of a photographed target.

[0091] A first construction unit 220 is configured to construct a space detection grid body surrounding the basic three-dimensional digital model, wherein the space detection grid body comprises a plurality of micro unit grid bodies, and each micro unit grid body comprises a plurality of target vertices.

[0092] A collision unit 230 is configured to set a spherical detector with a preset radius range at each target vertex, acquire a number of collision points of each spherical detector and the basic three-dimensional digital model, and the collision points comprise intersection points and tangent points.

[0093] A second acquisition unit 240 is configured to acquire a spherical center position coordinate of the spherical detector and a space angle of a line connecting the spherical center to the collision point if the number of collision points of the spherical detector and the basic three-dimensional digital model is 1.

[0094] A second construction unit 250 is configured to construct a cocoon type space grid body according to a plurality of spherical center position coordinates and a plurality of space angles of lines, and a distance between the cocoon type space grid body and the basic three-dimensional digital model satisfies the preset radius range.

[0095] Optionally, the second construction unit 250 is configured to:

[0096] determine a connection relationship of the plurality of spherical center position coordinates according to the plurality of space angles of lines; and

[0097] connect the plurality of spherical center position coordinates to form the cocoon type space grid body according to the connection relationship.

[0098] Optionally, a camera load and an observation platform photograph the photographed target by using the cocoon type space grid body, a position of the camera load and the observation platform is the spherical center position coordinate, and an angle of the camera load and the observation platform towards the photographed target is the space angle of the line.

[0099] Optionally, the first construction unit further comprises a first screening unit configured to:

[0100] migrate each model vertex of the basic three-dimensional digital model by a preset distance along a normal direction corresponding to each model vertex of the basic three-dimensional digital model to obtain a plurality of first vertices.

[0101] connecting adjacent ones of the first vertices to obtain a plurality of lines of different lengths, and equally dividing the plurality of lines by a unit of the line of the minimum length to obtain a plurality of second vertices at equal intervals;

[0102] screening the plurality of target vertices by using the second vertices;

[0103] the collision unit 230 is configured to:

[0104] setting a spherical detector with a preset radius range for the target vertex which is within a limited interval from the second vertex.

[0105] Optionally, the method further comprises a second screening unit configured to:

[0106] enlarging the basic three-dimensional digital model by a preset ratio according to an axial point of the basic three-dimensional digital model to obtain a plurality of third vertices, connecting adjacent ones of the third vertices to obtain a plurality of lines of different lengths, and equally dividing the plurality of lines by a unit of the line of the minimum length to obtain a plurality of fourth vertices at equal intervals;

[0107] screening the plurality of target vertices by using the fourth vertices;

[0108] the collision unit 230 is configured to:

[0109] setting a spherical detector with a preset radius range for the target vertex which is within a limited interval from the fourth vertex.

[0110] Optionally, the line space angle comprises a yaw angle, a pitch angle and a roll angle, the plurality of micro-unit grid bodies are cuboids of the same size, and a shooting density of the shooting by using the cocoon-type space grid body is determined according to the size of the cuboid.

[0111] Based on the construction method of the cocoon-type space grid body provided in the above embodiments, an embodiment of the present application further provides a construction device of the cocoon-type space grid body, which comprises:

[0112] The processor can be one or more. In some embodiments of the present application, the processor and the memory can be connected by a bus or other means.

[0113] The memory can include a read-only memory and a random access memory, and provide instructions and data for the processor. A part of the memory can also include an NVRAM. The memory stores an operating system and operation instructions, executable modules or data structures, or subsets thereof, or extended sets thereof, wherein the operation instructions can include various operation instructions for implementing various operations. The operating system can include various system programs for implementing various basic services and processing hardware-based tasks.

[0114] The processor controls the operation of the terminal device, and the processor can also be referred to as a CPU.

[0115] The method disclosed in the embodiments of the present application can be applied to a processor or implemented by the processor. The processor can be an integrated circuit chip with a signal processing capability. In the implementation process, the steps of the above method can be completed by hardware integrated logic circuits in the processor or by software form instructions. The processor mentioned above can be a general processor, a DSP, an ASIC, an FPGA, or other programmable logic devices, discrete gates or transistor logic devices, discrete hardware components. The disclosed methods, steps and logic block diagrams in the embodiments of the present application can be implemented or executed. The general processor can be a microprocessor or the processor can also be any conventional processor. The steps of the method disclosed in combination with the embodiments of the present application can be directly embodied as a hardware code processor for execution, or a combination of hardware and software modules in the code processor for execution. The software module can be located in a random access memory, a flash memory, a read-only memory, a programmable read-only memory or an electrically erasable programmable memory, a register, or other mature storage media in the art. The storage medium is located in the storage, and the processor reads the information in the storage, and combines the hardware to complete the steps of the above method.

[0116] The embodiments of the present application also provide a computer readable storage medium for storing program codes, the program codes being used for executing any one of the methods in the embodiments of the above method.

[0117] In the context of the present application, the machine readable medium can be a tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus or device. The machine readable medium can be a machine readable signal medium or a machine readable storage medium. The machine readable medium can include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus or device, or any suitable combination of the above. More specific examples of machine readable storage media can include one or more wires, portable computer disks, hard disks, random access memories (RAM), read-only memories (ROM), erasable programmable read-only memories (EPROM or flash memory), optical fibers, compact disk read-only memories (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination of the above.

[0118] It should be noted that the computer-readable medium in the above embodiments of the present application can be a computer-readable signal medium or a computer-readable storage medium or any combination of the two. The computer-readable storage medium may, for example, but is not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, device or apparatus, or any combination of the above. More specific examples of the computer-readable storage medium can include, but are not limited to, an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the above. In this application, the computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, device or apparatus. In this application, the computer-readable signal medium can include a data signal carried in a baseband or as a part of a carrier wave, which carries computer-readable program code. Such a propagated data signal can take many forms, including but not limited to an electromagnetic signal, an optical signal, or any suitable combination of the above. The computer-readable signal medium can also be any computer-readable medium other than the computer-readable storage medium that can send, propagate or transmit a program for use by or in connection with an instruction execution system, device or apparatus. The program code contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to a wire, an optical fiber, an RF (radio frequency) or the like, or any suitable combination of the above.

[0119] When introducing the elements of various embodiments of the present application, the articles "a", "an" and "the" are intended to mean one or more elements, unless otherwise specified. The words "comprise", "comprises" and "comprising" are inclusive and mean that in addition to the listed elements, other elements can also be present.

[0120] It should be noted that those of ordinary skill in the art can understand that all or part of the processes in the above method embodiments can be completed by a computer program instructing relevant hardware, and the program can be stored in a computer-readable storage medium. When the program is executed, it can include the processes of the above method embodiments. The storage medium can be a magnetic disk, an optical disk, a read-only memory (ROM) or a random access memory (RAM), etc.

[0121] Computer program code for carrying out operations of the present application can be written in any combination of one or more programming languages, including an object oriented programming language such as Java, Smalltalk, C++ or the like, and conventional procedural programming languages, such as the "C" programming language or similar programming languages. The program code can execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer can be connected to the user's computer through any type of network, including a local area network (LAN) or a wide area network (WAN), or the connection can be made to an external computer (for example, through the Internet using an Internet Service Provider).

[0122] The embodiments of the present application further provide a computer program product, which, when running on a computer device, causes the computer device to execute any one of the methods of the preceding embodiments.

[0123] Each of the embodiments in the specification is described in a progressive manner, and the same or similar parts between the embodiments can be referred to each other. Each of the embodiments focuses on the difference from other embodiments. In particular, the device embodiments are described more simply because they are basically similar to the method embodiments, and the relevant parts can be referred to the part of the method embodiments.

[0124] The above only describes the preferred embodiments of the present application. Although the present application has been disclosed as above with the preferred embodiments, it is not intended to limit the present application. Any person skilled in the art can make many possible changes and modifications to the technical solutions of the present application, or modify equivalent embodiments with the disclosed methods and technical contents without departing from the scope of the technical solutions of the present application. Therefore, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present application, without departing from the content of the technical solutions of the present application, still belongs to the protection scope of the technical solutions of the present application.

Claims

1. A method of constructing a cocoon space grid, characterized by, The method comprises the following steps: acquiring a basic three-dimensional digital model of a photographed target; constructing a space detection grid body surrounding the basic three-dimensional digital model, the space detection grid body comprising a plurality of micro-unit grid bodies, and each micro-unit grid body comprising a plurality of target vertices; setting a spherical detector with a preset radius range at each target vertex, acquiring the number of collision points between each spherical detector and the basic three-dimensional digital model, and the collision points comprising intersection points and tangent points; if the number of collision points between the spherical detector and the basic three-dimensional digital model is 1, acquiring the spherical center position coordinates of the spherical detector and the spatial angle of the line connecting the spherical center to the collision point; constructing a cocoon-shaped space grid body according to the plurality of spherical center position coordinates and the plurality of spatial angles of the line, and the distance between the cocoon-shaped space grid body and the basic three-dimensional digital model satisfying the preset radius range.

2. The method of claim 1, wherein, The method further comprises the following steps: a camera load and an observation platform photograph the photographed target by using the cocoon-shaped space grid body, the position of the camera load and the observation platform being the spherical center position coordinates, and the angle of the camera load and the observation platform towards the photographed target being the spatial angle of the line. The method further comprises the following steps:

3. The method of claim 1, wherein, migrating each model vertex of the basic three-dimensional digital model by a preset distance along the normal direction corresponding to each model vertex to obtain a plurality of first vertices; connecting adjacent first vertices to obtain a plurality of lines with different lengths, and equally dividing the plurality of lines by the line with the minimum length to obtain a plurality of second vertices with equal intervals; 4. The method of claim 1, wherein, screening the plurality of target vertices by using the second vertices; the step of setting a spherical detector with a preset radius range at each target vertex comprises the following step: setting a spherical detector with a preset radius range at each target vertex with a distance from the second vertex within a limited interval. The method further comprises the following steps: enlarging the basic three-dimensional digital model by a preset ratio according to the axial point of the basic three-dimensional digital model to obtain a plurality of third vertices, connecting adjacent third vertices to obtain a plurality of lines with different lengths, and equally dividing the plurality of lines by the line with the minimum length to obtain a plurality of fourth vertices with equal intervals; screening the plurality of target vertices by using the fourth vertices; 5. The method of claim 1, wherein, the step of setting a spherical detector with a preset radius range at each target vertex comprises the following step: setting a spherical detector with a preset radius range at each target vertex with a distance from the fourth vertex within a limited interval. The spatial angle of the line comprises a yaw angle, a pitch angle and a roll angle, the plurality of micro-unit grid bodies are cuboids with the same size, and the photographing density by using the cocoon-shaped space grid body for photographing is determined according to the size of the cuboids. The method comprises the following steps: a first acquisition unit is configured to acquire a basic three-dimensional digital model of a photographed target; 6. The method of claim 1, wherein, ​ 7. A cocooning space grid construction apparatus, characterized by, ​ ​ A first constructing unit is configured to construct a space exploration grid body surrounding the basic three-dimensional digital model, the space exploration grid body comprising a plurality of micro-unit grid bodies, and each micro-unit grid body comprising a plurality of target vertices; A collision unit is configured to set a spherical detector with a preset radius range at each target vertex, and obtain a number of collision points of each spherical detector and the basic three-dimensional digital model, the collision points comprising intersection points and tangent points; A second obtaining unit is configured to, if the number of collision points of each spherical detector and the basic three-dimensional digital model is 1, obtain a spherical center position coordinate of the spherical detector and a spatial angle of a line connecting the spherical center and the collision point; A second constructing unit is configured to construct a cocoon-type space grid body according to a plurality of spherical center position coordinates and a plurality of spatial angles of the lines, and a distance between the cocoon-type space grid body and the basic three-dimensional digital model satisfies the preset radius range.

8. A cocooning space grid construction device, characterized by The device comprises a processor and a memory; The memory is configured to store instructions; The processor is configured to execute the instructions in the memory, and execute the method in any one of claims 1-6.

9. A computer-readable storage medium, characterized in that, The computer readable storage medium is configured to store a computer program, and when the computer program runs on a computer device, the computer device executes the method in any one of claims 1-6.

10. A computer program product comprising a computer program, characterized in that, When the computer program runs on a computer device, the computer device executes the method in any one of claims 1-6.

Images