Geometric contour reconstruction method of rule elements and computer program product

Abstract

The invention discloses a geometric contour reconstruction method of rule elements and a computer program product. Comprising the following steps: firstly, obtaining an original geometric contour of a rule element through original point cloud data or an oblique photography model; original point cloud data or an oblique photography model is usually composed of a plurality of nodes, so that the obtained original geometric contour is relatively complex. Therefore, the nodes in the obtained original geometric contour can be grouped, and the nodes with similar directions can be determined. And then, regularizing and recombining the direction edges among the nodes in the node group by adopting an angle vector method to obtain corresponding regularized contour edges, thereby simplifying a plurality of nodes in the node group into two nodes of the regularized contour edges, and reducing the number of the nodes of the geometric contour of the regular element. And finally, reconstructing the geometric contour of the rule element through each regularized contour, and describing the rule element by using the more concise and accurate geometric contour so as to facilitate the subsequent processing of the rule element.

Description

Technical Field

[0001] The present invention relates to the technical field of computer-aided design of buildings, and in particular to a method for reconstructing the geometric outline of regular elements and a computer program product. Background Art

[0002] Oblique photography models or point cloud data can describe and express the real world with high precision. The original geometric contours of regular elements can be obtained from oblique photography models or point cloud data. However, due to the characteristics of oblique photography models and point cloud data, each edge of the original geometric contours is composed of many nodes, which makes the original geometric contours relatively complex and inconvenient for the subsequent processing of regular elements. Therefore, it is necessary to simplify the contour edges of multiple nodes to describe the regular elements with a more concise and accurate geometric contour for the subsequent processing of regular elements. Summary of the invention

[0003] In view of the shortcomings of the prior art, the present invention proposes a geometric contour reconstruction method of a regular element and a computer program product, which can simplify the geometric structure of the regular element and describe the regular element with a more concise and accurate geometric contour. The specific technical solution is as follows:

[0004] In a first aspect, a method for reconstructing a geometric outline of a regular element is provided. In a first implementable manner of the first aspect, the method comprises:

[0005] Obtain the original geometric outline of the regular feature, and group all nodes of the original geometric outline;

[0006] The angle vector method is used to simplify and reconstruct each node group to obtain the corresponding regularized contour edge;

[0007] The geometric contour of the regular element is reconstructed based on all the regularized contour edges.

[0008] In combination with the first implementable manner of the first aspect, in a second implementable manner of the first aspect, obtaining the original geometric outline of the regular element includes:

[0009] The original geometric outline of the regular element is obtained through the original point cloud data or the oblique photography model of the regular element.

[0010] In combination with the first implementable manner of the first aspect, in a third implementable manner of the first aspect, grouping all nodes of the rule element includes:

[0011] Traverse each node in turn according to the set direction, and calculate the azimuth angle between the direction edge connecting the current node and the previous node and the direction edge connecting the current node and the next node;

[0012] The calculated azimuth angle is compared with an angle threshold, and in response to the azimuth angle exceeding the angle threshold, the current node is regarded as a corner point;

[0013] All nodes between two adjacent corner points are grouped into the same group.

[0014] In combination with the first implementable manner of the first aspect, in a fourth implementable manner of the first aspect, the node groups are reconstructed respectively using an angle vector method, including:

[0015] Calculating the center of gravity of the regularized contour edge according to the coordinates of all nodes in the node group;

[0016] The starting points of the direction edges between the nodes in the node group are translated to the same starting point, and the vectors of all the translated direction edges are summed to obtain the direction vector of the regularized contour edge;

[0017] The regularized silhouette edge is reconstructed based on the center of gravity and the direction vector.

[0018] In combination with the fourth implementable manner of the first aspect, in a fifth implementable manner of the first aspect, calculating the direction vector of the regularized contour edge according to all the translated direction edge vectors includes:

[0019] The vector of each directional edge is compared with a preset vector threshold range, and in response to the vector of the directional edge not being within the vector threshold range, the vector of the directional edge is removed.

[0020] In combination with the first implementable manner of the first aspect, in a sixth implementable manner of the first aspect, reconstructing the geometric contour of the regular element based on all the regularized contour edges includes:

[0021] Determine the intersection points between each adjacent regularized contour edge according to the corresponding center of gravity and direction vector;

[0022] The intersection points are connected in sequence according to the connection order to reconstruct the regularized geometric outline of the regular element.

[0023] In a second aspect, a computer program product is provided, comprising a computer program / instruction, characterized in that when the computer program / instruction is executed by a processor, the steps of the method for reconstructing the geometric contour of regular elements as described in any one of the first to sixth implementable methods of the first aspect are implemented.

[0024] Beneficial effect: The geometric contour reconstruction method and computer program product of the regular element of the present invention can determine the nodes with similar directions by grouping all the nodes of the original geometric contour, and then use the angle vector method to reorganize the nodes of the same node group into a regularized contour edge, thereby reducing the number of nodes in the geometric contour of the regular element. Finally, the geometric contour of the regular element is reconstructed through the regularized contours, thereby describing the regular element with a more concise and accurate geometric contour. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the specific implementation of the present invention, the following will briefly introduce the drawings required for use in the specific implementation. In all the drawings, each element or part is not necessarily drawn according to the actual scale.

[0026] Figure 1 A flow chart of a method for reconstructing the geometric outline of a regular element provided by an embodiment of the present invention;

[0027] Figure 2 The original geometric outline of the building is obtained;

[0028] Figure 3 Schematic diagram of node grouping;

[0029] Figure 4 Schematic diagram of node grouping;

[0030] Figure 5 Schematic diagram for calculating the direction vector of the regularized contour edge;

[0031] Figure 6 A schematic diagram showing the comparison of a certain contour edge of the original geometric contour before and after reconstruction;

[0032] Figure 7 Schematic diagram comparing the geometric outlines before and after reconstruction of regular features. DETAILED DESCRIPTION

[0033] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and are therefore only used as examples, and cannot be used to limit the protection scope of the present invention.

[0034] like Figure 1 Flow chart of the geometric contour reconstruction method of the regular element shown, the reconstruction method comprises:

[0035] Step 1: Obtain the original geometric outline of the regular element and group all nodes of the original geometric outline;

[0036] Step 2: Use the angle vector method to simplify and reconstruct each node group to obtain the corresponding regularized contour edge;

[0037] Step 3: Reconstruct the geometric contour of the regular element based on all the regularized contour edges.

[0038] Specifically, first, the original geometric contour of the regular element can be obtained through the collected original point cloud data or oblique photography model. Since the original point cloud data or oblique photography model is usually composed of many nodes, the original geometric contour obtained is relatively complex. To this end, the nodes in the obtained original geometric contour can be grouped to determine the nodes with similar directions. Afterwards, the angle vector method can be used to regularize the directional edges between the nodes in the node group to obtain the corresponding regularized contour edges, thereby simplifying the multiple nodes in the node group into two nodes of the regularized contour edge, reducing the number of nodes in the geometric contour of the regular element. Finally, the geometric contour of the regular element can be reconstructed through each regularized contour, and the regular element can be described with a more concise and accurate geometric contour to facilitate the subsequent processing of the regular element.

[0039] In this embodiment, optionally, all nodes of the rule elements are grouped, including:

[0040] Traverse each node in turn according to the set direction, and calculate the azimuth angle between the direction edge connecting the current node and the previous node and the direction edge connecting the current node and the next node;

[0041] The calculated azimuth angle is compared with an angle threshold, and in response to the azimuth angle exceeding the angle threshold, the current node is regarded as a corner point;

[0042] All nodes between two adjacent corner points are grouped into the same group.

[0043] Specifically, when grouping nodes, each node can be traversed in turn according to the set direction. The direction angle between the direction edge connecting the current node and the previous node and the direction edge connecting the current node and the next node is calculated. The calculated direction angle is then compared with the angle threshold. If the direction angle exceeds the angle threshold, the current node is taken as a corner point. Repeating this process, all corner points in the original geometric outline of the regular element can be determined. The nodes between two adjacent corner points belong to nodes with similar directions, and all nodes between two adjacent corner points can be grouped together.

[0044] In this embodiment, the angle threshold can be set to 20°. Figure 2 The nodes of the building outline are grouped as shown. Figure 3 As shown in Figure 1, starting from point P, a total of 17 corner points are determined in the clockwise direction. The determined corner points are as follows: Figure 4 As shown, these 17 corner points are P1, P2, P3, ... P 17The nodes between P1 and P2 can be grouped into one group, and the nodes between P2 and P3 can be grouped into another group. Repeating this process, 17 node groups can be obtained.

[0045] In this embodiment, optionally, the node groups are reconstructed respectively using an angle vector method, including:

[0046] Calculating the center of gravity of the regularized contour edge according to the coordinates of all nodes in the node group;

[0047] The starting points of the direction edges between the nodes in the node group are translated to the same starting point, and the vectors of all the translated direction edges are summed to obtain the direction vector of the regularized contour edge;

[0048] The regularized silhouette edge is reconstructed based on the center of gravity and the direction vector.

[0049] Specifically, after all nodes of the regular element are grouped, the same angle idea can be used to reconstruct each node group. Specifically, first, the center of gravity of the regularized contour can be calculated according to the coordinates of all nodes in the node group. The specific calculation formula is as follows:

[0050]

[0051] Among them, x and y are the coordinates of the center of gravity, x i ,y i is the coordinate of the node, n is the number of nodes in the node group. The calculated centroid is the point through which the regularized contour edge passes.

[0052] Then, you can translate the starting points of the directional edges between the nodes in the node group to the same starting point, such as Figure 5 Then the direction vector of the regularized contour edge is calculated using the following formula:

[0053] o=e1+e1…e n ;

[0054] Among them, o is the direction vector of the regularized contour edge, e n is the direction edge vector.

[0055] The centroid and direction are used as control conditions. The centroid is the point through which the reconstructed contour edge passes. By calculating the direction vector, the reconstructed regularized contour edge can be obtained.

[0056] Taking the node group corresponding to P1 and P2 as an example, the regularized contour edge obtained by the above method is as follows: Figure 6 As shown. Figure 6 It can be seen that the above method can simplify the 12 nodes between P1 and P2 into two nodes, reducing the number of nodes of the regular element geometric outline.

[0057] In this embodiment, optionally, the direction vector of the regularized contour edge is calculated based on the vectors of all the directional edges after translation, including:

[0058] The vector of each directional edge is compared with a preset vector threshold range, and in response to the vector of the directional edge not being within the vector threshold range, the directional edge is removed.

[0059] Specifically, in order to reduce the impact of local errors, before using the angle vector method to reconstruct the regularized contour edge, the vectors of the edges in each direction after translation can be compared with the vector threshold range. If the vector of the direction edge is not within the vector threshold range, the direction edge can be removed from the node group and will not participate in the calculation of the direction vector of the regularized contour edge, thereby ensuring the accuracy of the reconstructed geometric contour.

[0060] In this embodiment, optionally, reconstructing the geometric contour of the regular element based on all the regularized contour edges includes:

[0061] Determine the intersection points between each adjacent regularized contour edge according to the corresponding center of gravity and direction vector;

[0062] The intersection points are connected in sequence according to the connection order to reconstruct the regularized geometric outline of the regular element.

[0063] Specifically, after obtaining the regularized contour edges corresponding to all node groups, the geometric contour of the regular element can be reconstructed through all the regularized contour edges. Specifically, first determine the intersection of two adjacent regularized contour edges according to the centroid and direction vector of each regularized contour edge. Then, connect all the calculated intersections in sequence according to the set connection order to obtain the geometric contour of the regular element. The obtained geometric contour is as follows: Figure 7 As shown. This realizes the regular reconstruction of regular elements and achieves the purpose of describing regular elements with more concise and accurate geometric contours.

[0064] A computer program product comprises a computer program / instruction, which, when executed by a processor, implements the steps of the above-mentioned method for reconstructing the geometric contour of regular elements.

[0065] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents. These modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and specification of the present invention.

Claims

1. A method for reconstructing the geometric contour of regular elements, characterized in that: include: Obtain the original geometric outline of the regular feature, and group all nodes of the original geometric outline; The angle vector method is used to simplify and reconstruct each node group to obtain the corresponding regularized contour edge; The geometric contour of the regular element is reconstructed based on all the regularized contour edges.

2. The geometric contour reconstruction method of regular elements according to claim 1, characterized in that: Get the original geometric outline of the regular feature, including: The original geometric outline of the regular element is obtained through the original point cloud data or the oblique photography model.

3. The geometric contour reconstruction method of regular elements according to claim 1, characterized in that: Grouping all nodes of the rule elements includes: Traverse each node in turn according to the set direction, and calculate the azimuth angle between the direction edge connecting the current node and the previous node and the direction edge connecting the current node and the next node; The calculated azimuth angle is compared with an angle threshold, and in response to the azimuth angle exceeding the angle threshold, the current node is regarded as a corner point; All nodes between two adjacent corner points are grouped into the same group.

4. The geometric contour reconstruction method of regular elements according to claim 1, characterized in that: The angle vector method is used to reconstruct the node groups separately, including: Calculating the center of gravity of the regularized contour edge according to the coordinates of all nodes in the node group; The starting points of the direction edges between the nodes in the node group are translated to the same starting point, and all the translated direction edge vectors are summed to obtain the direction vector of the regularized contour edge; The regularized silhouette edge is reconstructed based on the center of gravity and the direction vector.

5. The geometric contour reconstruction method of regular elements according to claim 4, characterized in that: The direction vector of the regularized contour edge is calculated based on the vectors of all the directional edges after translation, including: The vector of each directional edge is compared with a preset vector threshold range, and in response to the vector of the directional edge not being within the vector threshold range, the directional edge is removed.

6. The geometric contour reconstruction method of regular elements according to claim 1, characterized in that: Reconstructing the geometric contour of the regular element based on all the regularized contour edges, including: Determine the intersection points between each adjacent regularized contour edge according to the corresponding center of gravity and direction vector; The intersection points are connected in sequence according to the connection order to reconstruct the regularized geometric outline of the regular element.

7. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instructions are executed by a processor, the steps of the method for geometric contour reconstruction of regular elements as described in any one of claims 1-6 are implemented.

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