CN116137056A

CN116137056A - Facade sampling line generation method, device, equipment and storage medium

Info

Publication number: CN116137056A
Application number: CN202111357794.3A
Authority: CN
Inventors: 尤西霞
Original assignee: Beijing CHJ Automobile Technology Co Ltd
Current assignee: Beijing CHJ Automobile Technology Co Ltd
Priority date: 2021-11-16
Filing date: 2021-11-16
Publication date: 2023-05-19

Abstract

The embodiment of the application provides a method, a device, equipment and a storage medium for generating a vertical surface sampling line. In the method for generating the elevation sampling line, point cloud data of an object, a preset upper top line and a preset lower bottom line can be obtained, the sampling limit of the elevation sampling line is determined according to the upper top line and the lower bottom line, and a plurality of triangular planes are obtained by constructing a triangular network of the point cloud data in the sampling limit. And determining sampling points in the triangular planes according to preset sampling line interval values, and carrying out elevation line tracking in the triangular planes according to the elevations of the sampling points so as to obtain elevation sampling lines. By the implementation mode, the efficiency and the accuracy of drawing the elevation sampling line can be improved.

Description

Facade sampling line generation method, device, equipment and storage medium

Technical Field

The present invention relates to the field of map drawing, and in particular, to a method, an apparatus, a device, and a storage medium for generating a facade sampling line.

Background

With the continuous development of mapping technology, facade sampling lines are increasingly widely applied to numerous mapping scenes. In the prior art, elevation sampling lines are typically drawn manually. However, this way of manually drawing is less efficient and less accurate. Therefore, a solution is needed.

Disclosure of Invention

The embodiment of the application provides a method, a device, equipment and a storage medium for generating a vertical surface sampling line, which are used for accurately and rapidly generating the vertical surface sampling line.

The embodiment of the application provides a method for generating a vertical face sampling line, which comprises the following steps: acquiring point cloud data of an object and preset upper top lines and lower bottom lines; determining a sampling limit of a vertical surface sampling line according to the upper top line and the lower bottom line; performing triangle network construction operation on the point cloud data in the sampling limit to obtain a plurality of triangle planes; determining sampling points in the triangular planes according to preset sampling line interval values; and carrying out elevation line tracking on the triangular planes according to the elevation of the sampling point to obtain elevation sampling lines.

Further optionally, the upper top line is used for determining an upper limit value of the elevation sampling line; the lower bottom line is used for determining the lower limit value of the elevation sampling line.

Further optionally, performing a triangle network construction operation on the point cloud data within the sampling limit to obtain a plurality of triangle planes, including: performing triangle network construction operation according to the point cloud data to obtain a plurality of initial triangle planes; the screening operation is carried out on the plurality of initial triangular planes to obtain a plurality of triangular planes through the following steps: for any one of the plurality of initial triangular planes, judging whether the triangular plane is positioned above the upper top line or below the lower bottom line according to the elevation of the vertex of the triangular plane, the elevation corresponding to the upper top line and the elevation corresponding to the lower bottom line; and deleting the triangular plane if the triangular plane is positioned above the upper top line or below the lower bottom line.

Further optionally, determining sampling points in the plurality of triangular planes according to a preset sampling line interval value includes: acquiring the preset sampling line interval value; the sampling line interval value is used for describing the elevation difference of sampling points on two adjacent sampling lines; and determining a plurality of sampling points on the edges of the triangular planes according to the elevation of the upper top line and the sampling line interval.

Further optionally, according to the elevation of the sampling point, performing elevation line tracking in the triangular planes to obtain a facade sampling line, including: and sequentially connecting the points with the same elevation in every two adjacent triangular planes according to the elevations of the sampling points to obtain elevation sampling lines corresponding to the points with the same elevation.

Further optionally, before performing a triangle network construction operation on the point cloud data within the sampling limit to obtain a plurality of triangle planes, the method further includes: responding to the editing operation aiming at the point cloud data, and determining a point cloud editing area; the editing area includes: a point cloud recessed region or a point cloud protruding region; and supplementing point data in the point cloud editing area according to the editing operation so as to update the point cloud data.

Further optionally, performing a triangle network construction operation on the point cloud data within the sampling limit, and after obtaining a plurality of triangle planes, further includes: acquiring update information of the point cloud data; the updating information is obtained according to the fitting degree of the plurality of triangular planes and the point cloud data; and responding to the triangular network reconstruction operation, and performing triangular network reconstruction according to the update information of the point cloud data to obtain a plurality of updated triangular planes.

Further optionally, according to the elevation of the sampling point, performing elevation line tracking in the triangular planes to obtain elevation sampling lines, and further including: smoothing the elevation sampling line; and/or removing target sampling points on the elevation sampling line, wherein the distance between the target sampling points and the adjacent sampling points is smaller than a preset distance threshold value; and/or intercepting the elevation sampling line by using the upper top line or the lower bottom line so that the elevation sampling line is positioned within the sampling limit.

The embodiment of the application provides a facade sampling line generating device, including: the data acquisition module is used for acquiring point cloud data of an object and preset upper top lines and lower bottom lines; the sampling limit determining module is used for determining the sampling limit of the elevation sampling line according to the upper top line and the lower bottom line; the triangle network construction module is used for carrying out triangle network construction operation on the point cloud data in the sampling limit to obtain a plurality of triangle planes; the sampling point determining module is used for determining sampling points in the triangular planes according to a preset sampling line interval value; and the elevation line tracking module is used for carrying out elevation line tracking on the plurality of triangular planes according to the elevation of the sampling point to obtain an elevation sampling line.

The embodiment of the application also provides electronic equipment, which comprises: a memory and a processor; wherein the memory is for: store one or more computer instructions; the processor is configured to execute the one or more computer instructions to: the steps in the above-described facade sampling line generation method are performed.

The embodiment of the application also provides a computer readable storage medium storing a computer program, and the computer program can realize the steps in the vertical surface sampling line generation method when being executed.

In the method, the device, the equipment and the storage medium for generating the elevation sampling line, point cloud data of an object, a preset upper top line and a preset lower bottom line can be obtained, a sampling limit of the elevation sampling line is determined according to the upper top line and the lower bottom line, and a plurality of triangular planes are obtained by constructing a triangle network of the point cloud data in the sampling limit. And determining sampling points in the triangular planes according to preset sampling line interval values, and carrying out elevation line tracking in the triangular planes according to the elevations of the sampling points so as to obtain elevation sampling lines. By the implementation mode, the efficiency and the accuracy of drawing the elevation sampling line can be improved.

Drawings

The accompanying drawings, which are included to provide a further understanding of the application and are incorporated in and constitute a part of this application, illustrate embodiments of the application and together with the description serve to explain the application and do not constitute an undue limitation to the application. In the drawings:

FIG. 1 is a flow chart of a method for generating an elevation sampling line according to an exemplary embodiment of the present application;

FIG. 2 is a schematic diagram of a triangular mesh provided in an exemplary embodiment of the present application;

FIG. 3 is a schematic diagram of a sampling line according to an exemplary embodiment of the present application;

FIG. 4 is a schematic view of a sampling line cut provided in an exemplary embodiment of the present application;

fig. 5 is a flowchart in a practical application scenario provided in an exemplary embodiment of the present application;

FIG. 6 is a schematic diagram of an elevation sample line generating device according to an exemplary embodiment of the present application;

fig. 7 is a schematic structural diagram of an electronic device according to an exemplary embodiment of the present application.

Detailed Description

For the purposes, technical solutions and advantages of the present application, the technical solutions of the present application will be clearly and completely described below with reference to specific embodiments of the present application and corresponding drawings. It will be apparent that the described embodiments are only some, but not all, of the embodiments of the present application. All other embodiments, which can be made by one of ordinary skill in the art without undue burden from the present disclosure, are within the scope of the present disclosure.

Aiming at the mode of manually drawing the sampling line in the prior art, the efficiency and the accuracy are lower. In response to this technical problem, in some embodiments of the present application, a method for generating a facade sampling line is provided.

In the method for generating the elevation sampling line, point cloud data of an object, a preset upper top line and a preset lower bottom line can be obtained, the sampling limit of the elevation sampling line is determined according to the upper top line and the lower bottom line, and a plurality of triangular planes are obtained by constructing a triangular network of the point cloud data in the sampling limit. And determining sampling points in the triangular planes according to preset sampling line interval values, and carrying out elevation line tracking in the triangular planes according to the elevations of the sampling points so as to obtain elevation sampling lines. The following describes in detail the technical solutions provided by the embodiments of the present application with reference to the accompanying drawings.

Fig. 1 is a flow chart of a method for generating an elevation sampling line according to an exemplary embodiment of the present application, as shown in fig. 1, the method includes:

and 11, acquiring point cloud data of an object and preset upper top lines and lower bottom lines.

And step 12, determining the sampling limit of the elevation sampling line according to the upper top line and the lower bottom line.

And 13, performing triangle network construction operation on the point cloud data in the sampling limit to obtain a plurality of triangle planes.

And step 14, determining sampling points in a plurality of triangular planes according to a preset sampling line interval value.

And 15, carrying out elevation line tracking on a plurality of triangular planes according to the elevations of the sampling points to obtain elevation sampling lines.

The execution main body of the embodiment may be a terminal device, where the terminal device may be a computer or a tablet computer, and a user may access an editing platform based on the terminal device to perform editing operations of top line and bottom line, and may process the generated triangle network and sampling line.

In this embodiment, the terminal device may acquire point cloud data of the object, and preset upper top lines and lower bottom lines. The upper top line and the lower bottom line can be manually selected and drawn by a user in advance on the editing platform according to the actual form of the object or according to preset drawing rules. An upper top line for determining an upper limit value of the elevation sampling line; the lower bottom line is used for determining the lower limit value of the elevation sampling line. A point cloud refers to a collection of massive points of a target surface property of an object. The object may be a building, infrastructure, road element, etc.

After the terminal equipment acquires the point cloud data of the object and the preset upper top line and lower bottom line, the sampling limit of the elevation sampling line can be determined according to the upper top line and the lower bottom line.

After determining the sampling limit, the triangle network construction operation can be performed on the point cloud data within the sampling limit, so as to obtain a plurality of triangle planes. Specifically, the triangle mesh construction operation can be performed by using the characteristics of empty circles, maximized minimum angles and the like in Delaunay (triangulation algorithm). Wherein, as shown in fig. 2, the constructed triangular net is composed of a plurality of triangular planes.

After the step of constructing the triangular mesh, sampling points may be determined in a plurality of triangular planes according to a preset sampling line interval value. The sampling line interval value is used for describing the elevation difference of sampling points on two adjacent sampling lines. The sampling line interval may be set by a user on an editing platform. For example, the difference 10 between the height of the sampling line L1 with the height of 20 and the height of the sampling line L2 with the height of 30 is the sampling line interval value.

Where a sampling point refers to a point determined from the edge of a triangular plane that satisfies a specified condition, a plurality of sampling points may constitute a facade sampling line. When drawing the elevation sampling line, the points on the edges of the triangular planes can be circularly sampled. Where the loop samples points on the sides of multiple triangular planes, the first sampled point meeting the specified condition may be referred to as the starting sampling point.

For example, as shown in fig. 3, in the triangle mesh of fig. 3, if the first sampled sampling point satisfying the specified condition is point a in the process of loop judgment, point a may be taken as the sampling start point.

After the sampling points are determined, elevation line tracking can be performed on the triangular planes according to the elevations of the sampling points, so as to obtain elevation sampling lines. Where elevation refers to the Z value in the projected coordinate system (i.e., the value on the normal direction coordinate axis), elevation tracking refers to the operation of finding points of the same elevation and connecting the points of the same elevation. Taking the above example as a starting point, assuming that the coordinates of the point a in the projection coordinate system are (3, 6, 8), another point having the same height as the point a, i.e., a point B, C, D, E having a height of 8 can be found in the triangular plane shown in fig. 3. A, B, C, D, E are connected in sequence to form a vertical sampling line. Similarly, other sampling points can be determined, and points with the same elevation can be connected by the elevation line tracking method, so that the elevation sampling line can be obtained.

In this embodiment, the terminal device may acquire point cloud data of an object, a preset upper top line and a preset lower bottom line, determine a sampling limit of a facade sampling line according to the upper top line and the lower bottom line, and perform a triangle network construction operation on the point cloud data within the sampling limit to obtain a plurality of triangle planes. And determining sampling points in the triangular planes according to preset sampling line interval values, and carrying out elevation line tracking in the triangular planes according to the elevations of the sampling points so as to obtain elevation sampling lines. By the implementation mode, the efficiency and the accuracy of drawing the elevation sampling line can be improved.

In some alternative embodiments, performing a triangle mesh construction operation on the point cloud data within the sampling limit to obtain a plurality of triangle planes may be implemented based on the following steps.

And carrying out the construction operation of the triangular network according to the point cloud data to obtain a plurality of initial triangular planes. Wherein the initial triangle plane refers to a triangle plane generated based on all the input point cloud data. After the triangular net is constructed, the sampling limit of the elevation sampling line can be determined according to the upper top line and the lower bottom line, and the step aims to prevent the sampling line from being generated outside the sampling limit and causing unnecessary resource waste.

Optionally, after obtaining the plurality of initial triangular planes, the screening operation may be performed on the plurality of initial triangular planes to obtain a plurality of triangular planes by:

for any one of the plurality of initial triangular planes, judging whether the triangular plane is positioned above the upper top line or below the lower bottom line according to the elevation of the vertex of the triangular plane, the elevation corresponding to the upper top line and the elevation corresponding to the lower bottom line. If the triangle plane is located above the upper top line or below the lower bottom line, the triangle plane is deleted.

Specifically, three vertexes of the triangle plane can be sequentially ordered from large to small in height, and a vertex with the largest height and a vertex with Gao Chengzui small height are selected. If the highest vertex of the triangle plane has a higher elevation than Gao Chengxiao corresponding to the bottom line, it can be determined that the triangle plane is located below the bottom line. If the vertex of the triangle plane, which is Cheng Zui small in height, has a greater elevation than the elevation corresponding to the upper vertex line, then it can be determined that the triangle plane is located above the upper vertex line. For example, the coordinates of the vertex 1, the vertex 2 and the vertex 3 of the triangle plane in the projection coordinate system are (1, 2, 8), (2, 4, 9) and (4, 6, 10), respectively, and assuming that the elevation corresponding to the lower base line is 11 and the elevation 10 of the vertex 3 with the largest elevation is smaller than the elevation 11 corresponding to the lower base line, it is determined that the triangle plane is located below the lower base line, and the triangle plane is deleted.

Based on the above screening process, the triangle plane located above the upper top line or below the lower bottom line can be deleted to reduce the drawing calculation amount.

In some alternative embodiments, in order to make the generated triangle mesh more conform to the shape of the object, the following steps may be performed to supplement the point cloud data before performing the triangle mesh construction operation on the point cloud data within the sampling limit to obtain a plurality of triangle planes.

And responding to the editing operation of the user on the point cloud data in the editing platform, and determining a point cloud editing area. Wherein the editing area includes: a point cloud recessed region or a point cloud protruding region. The editing region may be represented by coordinate boundaries, for example, a point cloud concave region or a point cloud convex region is 1< x <2,4< y <5, and 8< z <10.

According to the user editing operation, the terminal device can supplement the point data in the point cloud editing area so as to update the point cloud data. For example, the user adds two points (5, 6, 7), (5,5,8) in the point cloud editing area on the operation platform, and in response to this editing operation by the user, the terminal device can supplement the two points (5, 6, 7), (5,5,8) in the editing area.

By the steps, the point data are supplemented, so that the triangle net generated by the updated point cloud data is smoother than the triangle net generated by the point cloud data before updating.

In some scenes, after the triangle network construction operation is performed on the point cloud data in the sampling limit, the fitting degree of the triangle network and the point cloud data is poor. In order to improve the fitting degree of the triangle mesh and the point cloud data, in some alternative embodiments, after performing the triangle mesh construction operation according to the point cloud data to obtain a plurality of triangle planes, the following steps may be performed to reconstruct the triangle mesh.

And acquiring update information of the point cloud data. The updating information is obtained according to the fitting degree of the plurality of triangular planes and the point cloud data. The fitting degree is used for representing the fitting probability of the triangular planes and the point cloud data, and the fitting degree can be compared with a preset fitting degree threshold value, so that whether the fitting degree of the point cloud data and the triangular planes is good or not is judged. The fit threshold may be 80%, 70% or 60% equivalent, which is not limited in this embodiment.

If the bonding degree is smaller than the bonding threshold value, the point cloud data can be updated; if the bonding degree is greater than the bonding threshold, the point cloud data may not be updated. In some scenarios, the user may check, at the editing platform, whether the generated triangle mesh meets the actual surface features and other features of the object, whether certain points fly, and input the fitting degree of a plurality of triangle planes and point cloud data through the operation experience, which aims to prevent the generated triangle mesh from being inconsistent with the actual form of the object. For example, the preset bonding degree threshold value is 70%, the user checks the triangle net generated according to the point cloud data on the surface of a certain building, and finds that the triangle net is greatly deviated from the actual surface of the building, some points have a flying phenomenon, and the user inputs 50% bonding degree according to experience and is smaller than the bonding degree threshold value, so that the updating information of the point cloud data is obtained.

And reconstructing the triangular network according to the obtained updated information. Specifically, responding to the triangle network reconstruction operation, and performing triangle network reconstruction according to the update information of the point cloud data to obtain a plurality of updated triangle planes.

In some alternative embodiments, determining sampling points in a plurality of triangular planes according to a preset sampling line interval value may be implemented based on the following steps:

step 141, obtaining a preset sampling line interval value. The sampling line interval value is used for describing the elevation difference of sampling points on two adjacent sampling lines.

Based on the above-described sampling line interval values, the following steps may be performed to determine a plurality of sampling points.

Step 142, determining a plurality of sampling points on the edges of the triangular planes according to the elevation of the upper top line and the sampling line interval. For example, if the elevation of the upper top line is 50 and the sampling line interval is 5, then a plurality of sampling points with the elevations of 45, 40 and 35 equivalent can be determined. That is, points with a height of 45, points with a height of 40, and points with a height of 35 are found on the sides of the triangular planes.

After determining the plurality of sampling points based on the step 142, the points with the same elevation in the triangular planes adjacent to each other can be sequentially connected according to the elevation of the plurality of sampling points, so as to obtain elevation sampling lines corresponding to the points with the same elevation.

Continuing with the illustration of the previous example embodiment, it is assumed that triangular planes are drawn from the point cloud data, which are triangular planes S1, S2, and S3, respectively. Wherein, the triangular plane S1 is adjacent to the triangular plane S2, and the triangular plane S2 is adjacent to the triangular plane S3. After a plurality of sampling points with the elevation of 45 are obtained in the triangular planes S1, S2 and S3, two points with the elevation of 45 in the S1 and the S2 can be connected, and then two points with the elevation of 45 in the S2 and the S3 are connected, so that a vertical sampling line with the elevation of 45 is obtained. Similarly, a plurality of points with the elevation of 40 in the triangular planes S1, S2 and S3 are sequentially connected, so that a vertical sampling line with the elevation of 40 can be obtained, and the description is omitted.

In some alternative embodiments, after elevation line tracking is performed in multiple triangular planes according to the elevation of the sampling point, the elevation sampling line may be optimized by the following implementation.

In the first embodiment, the facade sampling line is smoothed, specifically, the Douglas-Peuker algorithm is adopted for thinning, so that the facade sampling line is smoother. The 3-point 5-point 7-point linear smoothing strategy may also be used to smooth the vertical sampling line, which is not limited in this embodiment.

In the second embodiment, the target sampling points on the elevation sampling line, the distance between which and the adjacent sampling points is smaller than the preset distance threshold value, are removed. The preset distance threshold may be 0.5m, 1m, or 2m, which is not limited in this embodiment, and the target sampling point refers to one of two adjacent sampling points with a distance smaller than the distance threshold. Illustratively, if the facade sampling line has two adjacent sampling points U1 and U2 with a distance of 0.4m and a distance threshold value smaller than 0.5m, one of the target sampling points U1 and U2 is removed.

In the third embodiment, the vertical surface sampling line is intercepted by using the upper top line or the lower bottom line. This step aims at having the facade sampling line within the sampling limit. As shown in fig. 4, sampling lines L3, L4, L5, and L6 are taken by the upper top line.

The first, second and third embodiments may be executed alone or in combination, and the present embodiment is not limited thereto.

The method for generating the elevation sampling line according to the embodiment of the present application will be further described with reference to fig. 5 and a practical application scenario.

As shown in FIG. 5, after the user opens the facade job page, the upper top line and lower bottom line may be drawn to determine the facade limits. If the elevation is uneven, shape points are added at the shape change position, so that a TIN (Triangulated Irregular Network, irregular triangular net) with constraint based on an upper top line and a lower bottom line is constructed. After the TIN is constructed, illegal triangles can be deleted, sampling line generation positions can be judged, each triangular net is determined to generate a corresponding elevation sampling line, and then points with the same elevation are connected to form the sampling line. Based on the above steps, the sampling line shape points can be optimized. And finally, assembling the upper top line, the sampling line and the lower bottom line into a complete vertical face structure and outputting. Through the steps, a user can generate and optimize the sampling line under the actual application scene, so that the rate and accuracy of sampling line generation are improved.

It should be noted that, the execution subjects of each step of the method provided in the above embodiment may be the same device, or the method may also be executed by different devices. For example, the execution subject of steps 11 to 15 may be the device a; for another example, the execution subject of

steps

11 and 12 may be device a, and the execution subject of steps 13 to 15 may be device B; etc.

In addition, in some of the flows described in the above embodiments and the drawings, a plurality of operations appearing in a specific order are included, but it should be clearly understood that the operations may be performed out of the order in which they appear herein or performed in parallel, the sequence numbers of the operations such as 11, 12, etc. are merely used to distinguish between the various operations, and the sequence numbers themselves do not represent any order of execution. In addition, the flows may include more or fewer operations, and the operations may be performed sequentially or in parallel.

It should be noted that, the descriptions of "first" and "second" herein are used to distinguish different messages, devices, modules, etc., and do not represent a sequence, and are not limited to the "first" and the "second" being different types.

The embodiment of the application provides a facade sampling line generating device, as shown in fig. 6, the facade sampling line generating device includes: a data acquisition module 601, a sampling limit determination module 602, a triangle net construction module 603, a sampling point determination module 604, and an elevation line tracking module 605.

The data acquisition module 601 is configured to acquire point cloud data of an object and preset upper top lines and lower bottom lines; a sampling limit determining module 602, configured to determine a sampling limit of a facade sampling line according to the upper top line and the lower bottom line; the triangle net construction module 603 is configured to perform triangle net construction operation on the point cloud data within the sampling limit, so as to obtain a plurality of triangle planes; a sampling point determining module 604, configured to determine sampling points in the plurality of triangular planes according to a preset sampling line interval value; and the elevation line tracking module 605 is configured to perform elevation line tracking in the triangular planes according to the elevation of the sampling point, so as to obtain an elevation sampling line.

Further optionally, the triangle mesh construction module 603 performs triangle mesh construction operation on the point cloud data within the sampling limit to obtain a plurality of triangle planes, which is specifically configured to: performing triangle network construction operation according to the point cloud data to obtain a plurality of initial triangle planes; the screening operation is carried out on the plurality of initial triangular planes to obtain a plurality of triangular planes through the following steps: for any one of the plurality of initial triangular planes, judging whether the triangular plane is positioned above the upper top line or below the lower bottom line according to the elevation of the vertex of the triangular plane, the elevation corresponding to the upper top line and the elevation corresponding to the lower bottom line; and deleting the triangular plane if the triangular plane is positioned above the upper top line or below the lower bottom line.

Further optionally, the sampling point determining module 604 is specifically configured to, when determining sampling points in the plurality of triangular planes according to a preset sampling line interval value: acquiring the preset sampling line interval value; the sampling line interval value is used for describing the elevation difference of sampling points on two adjacent sampling lines; and determining a plurality of sampling points on the edges of the triangular planes according to the elevation of the upper top line and the sampling line interval.

Further optionally, the elevation line tracking module 605 is specifically configured to, when performing elevation line tracking in the plurality of triangular planes according to the elevation of the sampling point to obtain an elevation sampling line: and sequentially connecting the points with the same elevation in every two adjacent triangular planes according to the elevations of the sampling points to obtain elevation sampling lines corresponding to the points with the same elevation.

Further optionally, before performing a triangle mesh construction operation on the point cloud data within the sampling limit, the triangle mesh construction module 603 is further configured to: responding to the editing operation aiming at the point cloud data, and determining a point cloud editing area; the editing area includes: a point cloud recessed region or a point cloud protruding region; and supplementing point data in the point cloud editing area according to the editing operation so as to update the point cloud data.

Further optionally, the triangle mesh construction module 603 is further configured to, after performing triangle mesh construction operation on the point cloud data within the sampling limit, obtain a plurality of triangle planes: acquiring update information of the point cloud data; the updating information is obtained according to the fitting degree of the plurality of triangular planes and the point cloud data; and responding to the triangular network reconstruction operation, and performing triangular network reconstruction according to the update information of the point cloud data to obtain a plurality of updated triangular planes.

Further optionally, the elevation line tracking module 605 is further configured to, after performing elevation line tracking in the plurality of triangular planes according to the elevation of the sampling point, obtain an elevation sampling line: smoothing the elevation sampling line; and/or removing target sampling points on the elevation sampling line, wherein the distance between the target sampling points and the adjacent sampling points is smaller than a preset distance threshold value; and/or intercepting the elevation sampling line by using the upper top line or the lower bottom line so that the elevation sampling line is positioned within the sampling limit.

Fig. 7 is a schematic structural diagram of an electronic device according to an exemplary embodiment of the present application, as shown in fig. 7, including: memory 701 and processor 702.

The memory 701 is used for storing a computer program and may be configured to store other various data to support operations on the terminal device. Examples of such data include instructions for any application or method operating on the terminal device, contact data, phonebook data, messages, pictures, video, etc.

The memory 701 may be implemented by any type or combination of volatile or nonvolatile memory devices such as Static Random Access Memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic or optical disk.

A processor 702 coupled with the memory 701 for executing the computer program in the memory 701 for: acquiring point cloud data of an object and preset upper top lines and lower bottom lines; determining a sampling limit of a vertical surface sampling line according to the upper top line and the lower bottom line; performing triangle network construction operation on the point cloud data in the sampling limit to obtain a plurality of triangle planes; determining sampling points in the triangular planes according to preset sampling line interval values; and carrying out elevation line tracking on the triangular planes according to the elevation of the sampling point to obtain elevation sampling lines.

Further optionally, when performing a triangle network construction operation on the point cloud data within the sampling limit, the processor 702 is specifically configured to: performing triangle network construction operation according to the point cloud data to obtain a plurality of initial triangle planes; the screening operation is carried out on the plurality of initial triangular planes to obtain a plurality of triangular planes through the following steps: for any one of the plurality of initial triangular planes, judging whether the triangular plane is positioned above the upper top line or below the lower bottom line according to the elevation of the vertex of the triangular plane, the elevation corresponding to the upper top line and the elevation corresponding to the lower bottom line; and deleting the triangular plane if the triangular plane is positioned above the upper top line or below the lower bottom line.

Further optionally, the processor 702 is specifically configured to, when determining the sampling points in the plurality of triangular planes according to the sampling limit and according to a preset sampling line interval value: acquiring the preset sampling line interval value; the sampling line interval value is used for describing the elevation difference of sampling points on two adjacent sampling lines; and determining a plurality of sampling points on the edges of the triangular planes according to the elevation of the upper top line and the sampling line interval.

Further optionally, the processor 702 is specifically configured to, when performing elevation line tracking in the plurality of triangular planes according to the elevation of the sampling point to obtain an elevation sampling line: and sequentially connecting the points with the same elevation in every two adjacent triangular planes according to the elevations of the sampling points to obtain elevation sampling lines corresponding to the points with the same elevation.

Further optionally, the processor 702 is further configured to: responding to the editing operation aiming at the point cloud data, and determining a point cloud editing area; the editing area includes: a point cloud recessed region or a point cloud protruding region; and supplementing point data in the point cloud editing area according to the editing operation so as to update the point cloud data.

Further optionally, the processor 702 is further configured to, after performing a triangle mesh construction operation according to the point cloud data, obtain a plurality of triangle planes: acquiring update information of the point cloud data; the updating information is obtained according to the fitting degree of the plurality of triangular planes and the point cloud data; and responding to the triangular network reconstruction operation, and performing triangular network reconstruction according to the update information of the point cloud data to obtain a plurality of updated triangular planes.

Further optionally, the processor 702 is further configured to, after performing elevation line tracking in the plurality of triangular planes according to the elevation of the sampling point, obtain an elevation sampling line: smoothing the elevation sampling line; and/or removing target sampling points on the elevation sampling line, wherein the distance between the target sampling points and the adjacent sampling points is smaller than a preset distance threshold value; and/or intercepting the elevation sampling line by using the upper top line or the lower bottom line so that the elevation sampling line is positioned within the sampling limit.

The memory of fig. 7 described above may be implemented by any type of volatile or non-volatile memory device or combination thereof, such as Static Random Access Memory (SRAM), electrically erasable programmable read-only memory (EEPROM), erasable programmable read-only memory (EPROM), programmable read-only memory (PROM), read-only memory (ROM), magnetic memory, flash memory, magnetic or optical disk.

The display 703 in fig. 7 described above includes a screen, which may include a Liquid Crystal Display (LCD) and a Touch Panel (TP). If the screen includes a touch panel, the screen may be implemented as a touch screen to receive input signals from a user. The touch panel includes one or more touch sensors to sense touches, swipes, and gestures on the touch panel. The touch sensor may sense not only the boundary of a touch or slide action, but also the duration and pressure associated with the touch or slide operation.

Further, as shown in fig. 7, the electronic device further includes: communication component 704, power supply component 705, and other components. Only some of the components are schematically shown in fig. 7, which does not mean that the electronic device only comprises the components shown in fig. 7.

The communication component 704 in fig. 7 described above is configured to facilitate communication between the device in which the communication component resides and other devices, either in a wired or wireless manner. The device in which the communication component is located may access a wireless network based on a communication standard, such as WiFi,2G, 3G, 4G, or 5G, or a combination thereof. In one exemplary embodiment, the communication component receives a broadcast signal or broadcast-related information from an external broadcast management system via a broadcast channel. In one exemplary embodiment, the communication component may be implemented based on Near Field Communication (NFC) technology, radio Frequency Identification (RFID) technology, infrared data association (IrDA) technology, ultra Wideband (UWB) technology, bluetooth (BT) technology, and other technologies.

Wherein the power supply assembly 705 provides power to the various components of the device in which the power supply assembly is located. The power components may include a power management system, one or more power sources, and other components associated with generating, managing, and distributing power for the devices in which the power components are located.

In this embodiment, point cloud data of an object, a preset upper top line and a preset lower bottom line may be obtained, a sampling limit of a facade sampling line is determined according to the upper top line and the lower bottom line, and a plurality of triangular planes are obtained by performing a triangle network construction operation on the point cloud data within the sampling limit. And determining sampling points in the triangular planes according to preset sampling line interval values, and carrying out elevation line tracking in the triangular planes according to the elevations of the sampling points so as to obtain elevation sampling lines. By the implementation mode, the efficiency and the accuracy of drawing the elevation sampling line can be improved.

Accordingly, embodiments of the present application also provide a computer-readable storage medium storing a computer program, which when executed by a processor causes the processor to implement steps in a facade sampling line generation method.

It will be appreciated by those skilled in the art that embodiments of the present invention may be provided as a method, system, or computer program product. Accordingly, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present invention is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the invention. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In one typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include volatile memory in a computer-readable medium, random Access Memory (RAM) and/or nonvolatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM). Memory is an example of computer-readable media.

Computer readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Disks (DVD) or other optical storage, magnetic cassettes, magnetic disk storage or other magnetic storage devices, or any other non-transmission medium which can be used to store information that can be accessed by a computing device. Computer-readable media, as defined herein, does not include transitory computer-readable media (transmission media), such as modulated data signals and carrier waves.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article or apparatus that comprises the element.

The foregoing is merely exemplary of the present application and is not intended to limit the present application. Various modifications and changes may be made to the present application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc. which are within the spirit and principles of the present application are intended to be included within the scope of the claims of the present application.

Claims

1. A method for generating a facade sampling line, comprising:

acquiring point cloud data of an object and preset upper top lines and lower bottom lines;

determining a sampling limit of a vertical surface sampling line according to the upper top line and the lower bottom line;

Performing triangle network construction operation on the point cloud data in the sampling limit to obtain a plurality of triangle planes;

determining sampling points in the triangular planes according to preset sampling line interval values;

and carrying out elevation line tracking on the triangular planes according to the elevation of the sampling point to obtain elevation sampling lines.

2. The method of claim 1, wherein the upper top line is used to determine an upper limit value for elevation of the facade sampling line; the lower bottom line is used for determining the lower limit value of the elevation sampling line.

3. The method of claim 1, wherein performing a triangle mesh construction operation on the point cloud data within the sampling limit to obtain a plurality of triangle planes comprises:

performing triangle network construction operation according to the point cloud data to obtain a plurality of initial triangle planes;

the screening operation is carried out on the plurality of initial triangular planes to obtain a plurality of triangular planes through the following steps:

for any one of the plurality of initial triangular planes, judging whether the triangular plane is positioned above the upper top line or below the lower bottom line according to the elevation of the vertex of the triangular plane, the elevation corresponding to the upper top line and the elevation corresponding to the lower bottom line;

And deleting the triangular plane if the triangular plane is positioned above the upper top line or below the lower bottom line.

4. The method of claim 1, wherein determining sampling points in the plurality of triangular planes based on a preset sampling line interval value comprises:

acquiring the preset sampling line interval value; the sampling line interval value is used for describing the elevation difference of sampling points on two adjacent sampling lines;

and determining a plurality of sampling points on the edges of the triangular planes according to the elevation of the upper top line and the sampling line interval.

5. The method of claim 4, wherein performing elevation line tracking in the plurality of triangular planes based on the elevation of the sampling point to obtain elevation sampling lines comprises:

and sequentially connecting the points with the same elevation in every two adjacent triangular planes according to the elevations of the sampling points to obtain elevation sampling lines corresponding to the points with the same elevation.

6. The method of claim 1, wherein performing a triangle mesh construction operation on the point cloud data within the sampling limit, before obtaining a plurality of triangle planes, further comprises:

Responding to the editing operation aiming at the point cloud data, and determining a point cloud editing area; the editing area includes: a point cloud recessed region or a point cloud protruding region;

and supplementing point data in the point cloud editing area according to the editing operation so as to update the point cloud data.

7. The method of claim 1, wherein performing a triangle mesh construction operation on the point cloud data within the sampling limit to obtain a plurality of triangle planes, further comprises:

acquiring update information of the point cloud data; the updating information is obtained according to the fitting degree of the plurality of triangular planes and the point cloud data;

and responding to the triangular network reconstruction operation, and performing triangular network reconstruction according to the update information of the point cloud data to obtain a plurality of updated triangular planes.

8. The method of any of claims 1-7, wherein performing elevation line tracking in the plurality of triangular planes based on the elevation of the sampling point, after obtaining the elevation sampling line, further comprises:

smoothing the elevation sampling line; and/or the number of the groups of groups,

removing target sampling points on the elevation sampling line, wherein the distance between the target sampling points and the adjacent sampling points is smaller than a preset distance threshold value; and/or the number of the groups of groups,

And intercepting the vertical surface sampling line by utilizing the upper top line or the lower bottom line so that the vertical surface sampling line is positioned in the sampling limit.

9. A facade sampling line generating device, characterized by comprising:

the data acquisition module is used for acquiring point cloud data of an object and preset upper top lines and lower bottom lines;

the sampling limit determining module is used for determining the sampling limit of the elevation sampling line according to the upper top line and the lower bottom line;

the triangle network construction module is used for carrying out triangle network construction operation on the point cloud data in the sampling limit to obtain a plurality of triangle planes;

the sampling point determining module is used for determining sampling points in the triangular planes according to a preset sampling line interval value;

and the elevation line tracking module is used for carrying out elevation line tracking on the plurality of triangular planes according to the elevation of the sampling point to obtain an elevation sampling line.

10. An electronic device, comprising: a memory and a processor;

wherein the memory is for: store one or more computer instructions;

the processor is configured to execute the one or more computer instructions to: performing the steps of the method of any one of claims 1-8.

11. A computer readable storage medium storing a computer program, characterized in that the computer program, when executed by a processor, causes the processor to carry out the steps of the method according to any one of claims 1-8.