CN-121600218-B - Building exterior surface model rapid construction method based on BIM technology

CN121600218BCN 121600218 BCN121600218 BCN 121600218BCN-121600218-B

Abstract

The invention relates to the technical field of three-dimensional modeling, in particular to a building exterior surface model rapid construction method based on BIM technology, which is used for solving the technical problem of insufficient model precision of BIM modeling in the prior art. The method comprises the steps of constructing a first triangular mesh model based on building outer surface data, calculating first folding costs of each side of each triangle in the first triangular mesh model based on a secondary error measurement method, correcting the first folding costs of each side based on a first inhibition factor of each side and/or a second inhibition factor of each side to obtain second folding costs of each side, wherein the first inhibition factor is used for inhibiting folding costs of high-detail-density areas, the second inhibition factor is used for inhibiting folding costs of high-shape-change areas, and simplifying the sides in the first triangular mesh model based on the second folding costs of each side to obtain a second triangular mesh model.

Inventors

WANG PING
MA TIELIN
FENG SHIFEI
WU QIANG
CAI WENFENG
ZHAO DONGJIE
SUN BING
WANG PENGFEI
LI QIANG
ZHU YUNDA
DONG LISHENG

Assignees

辽宁云创大数据科技有限公司

Dates

Publication Date: 20260512
Application Date: 20251201

Claims (8)

1. A building exterior surface model rapid construction method based on BIM technology is characterized by comprising the following steps: Constructing a first triangular mesh model based on building exterior surface data, wherein the first triangular mesh model is a model formed by splicing a plurality of triangles and used for representing the shape of the building exterior surface; Calculating a first folding cost of each side of each triangle in the first triangular mesh model based on a secondary error measurement method; Correcting the first folding price of each side based on a first inhibition factor of each side and/or a second inhibition factor of each side to obtain a second folding cost of each side, wherein the first inhibition factor is used for inhibiting the folding cost of a high-detail-density region, and the second inhibition factor is used for inhibiting the folding cost of a high-shape change region; simplifying the edges in the first triangular mesh model based on the second folded price of each edge to obtain a second triangular mesh model; wherein prior to modifying the first folded price based on the first inhibitor and the second inhibitor, the method further comprises: Calculating the average area of adjacent triangles of two end points of a target side, wherein each adjacent triangle refers to a triangle taking one of the two end points of the target side as a triangle vertex, and the target side is any side in the first triangular mesh model; Calculating the average value of the average areas of the adjacent triangles of the two end points; Calculating a first inhibition factor of the target side based on the average value of the average areas, wherein the first inhibition factor of the target side is inversely related to the average area of the adjacent triangles; Calculating curvature characteristic values of two endpoints of a target edge, wherein the curvature characteristic values are used for representing the average change degree of the surface of the position where the endpoints are located; and calculating a second inhibition factor of the target side based on the maximum value in the curvature characteristic values of the two endpoints, wherein the second inhibition factor is positively correlated with the maximum value.
2. The method for quickly constructing a building exterior surface model based on the BIM technique according to claim 1, wherein the calculating the first suppression factor of the target edge based on the average value of the average areas includes: Determining a first inhibitor adjustment hyper-parameter; Calculating the ratio of the first inhibitor adjustment hyper-parameter to the average value of the average area; and taking the sum of the ratio and a first preset value as the first inhibition factor.
3. The method for quickly constructing a building external surface model based on the BIM technique according to claim 1, wherein the calculating the curvature characteristic values of the two end points of the target edge includes: Calculating the unit normal vector of each adjacent triangle of the endpoint; Multiplying the unit normal vector of each adjacent triangle by the area to obtain a weighted normal vector of each adjacent triangle; summing all the weighted normal vectors and normalizing the summation result to obtain an average weighted normal vector of the endpoint; calculating a space included angle between the unit normal vector of each adjacent triangle and the average weighting normal vector; And calculating the average value of the space included angles as the curvature characteristic value.
4. The method for quickly constructing a building exterior surface model based on the BIM technology according to claim 1, wherein the correcting the first folding price of each side based on the first inhibitor of each side and/or the second inhibitor of each side to obtain the second folding cost of each side includes: subtracting a second preset value from the sum of the first inhibition factor and the second inhibition factor of the target side to obtain a combined inhibition factor; taking the product of the combined suppression factor and the first folding cost as a second folding cost of the target edge.
5. The method for quickly constructing a building external surface model based on the BIM technology according to claim 1, wherein the simplifying the edges in the first triangular mesh model based on the second folded price of each edge to obtain a second triangular mesh model includes: step one, stacking and sorting edges according to the order of the second folding cost of the edges from small to large; selecting the side with the minimum second folding valence in the current sequencing to fold, and updating the connection relation between the rest side and the vertex to obtain a new triangular mesh model; step three, recalculating second folding cost of each edge in the new triangular mesh model; and iteratively executing the first step to the third step until the preset iteration times are reached or the simplification error of the new triangular mesh model is smaller than a first threshold value, and outputting the current triangular mesh model as the second triangular mesh model.
6. The method for quickly constructing a building exterior surface model based on the BIM technique according to claim 5, wherein selecting the side with the smallest second folding valence in the current ranking for folding includes: Deleting a folding edge which is required to be folded currently, two end points of the folding edge, and two triangles taking the folding edge as a common edge; calculating the positions of two vertexes of the folded edge based on a preset vertex generation algorithm to generate a new vertex; And updating the topological connection relation of the triangular mesh model based on the new vertex and the other two vertexes of the two triangles to form a new triangle.
7. The method for quickly constructing a building exterior surface model based on the BIM technology according to claim 1, wherein the constructing a first triangular mesh model based on building exterior surface data includes: acquiring initial three-dimensional point cloud data of the outer surface of the building, which is obtained by scanning the outer surface of the building by using laser radar equipment; Performing outlier filtering processing on the initial three-dimensional point cloud data to remove noise, and obtaining processed three-dimensional point cloud data; converting the processed three-dimensional point cloud data into triangular meshes based on a poisson curved surface reconstruction algorithm; and performing geometric processing, semantic mapping and parametric modeling on the triangular meshes to obtain the first triangular mesh model.
8. The method for quickly constructing a building exterior surface model based on the BIM technology according to claim 7, wherein the performing outlier filtering processing on the initial three-dimensional point cloud data to remove noise, and obtaining the processed three-dimensional point cloud data includes: setting a distance threshold based on a neighborhood distance between each point cloud data in the initial three-dimensional point cloud data; Deleting a target point in the initial three-dimensional point cloud data to obtain processed three-dimensional point cloud data, wherein the target point is a point with the target point as a center and the distance threshold as a radius range, and the number of the point cloud data is smaller than a second threshold.

Description

Building exterior surface model rapid construction method based on BIM technology Technical Field The invention relates to the technical field of three-dimensional modeling, in particular to a building exterior surface model rapid construction method based on a BIM technology. Background The current industries of building design and scheme creation, construction and engineering management, city planning and digital twin, historical building repair and the like all need to obtain high-precision building outer surfaces. In the related art, the external surface of the building can be constructed based on a building information model (Building Information Modeling, BIM) technology, and the method has the advantages of integrating various data, realizing three-dimensional visualization, construction prefabrication, precision control and the like. However, the BIM technology involves a huge amount of data, so that the modeling efficiency is low, and the high-precision modeling of the outer surface of the building cannot be obtained rapidly. In order to improve modeling efficiency, a BIM model needs to be simplified currently, for example, a side folding algorithm based on a secondary error metric is used for simplifying the BIM model to reduce the data size of the BIM model, and the side folding algorithm of the secondary error metric is used for realizing model simplification by calculating a geometric distance error generated by side folding as folding cost and sequentially folding the side with the smallest cost. However, in the simplified process, the edge folding algorithm of the secondary error measurement only uses a single geometric distance error as a measurement standard of folding cost, the measurement standard is single, the detail condition of the outer surface of the building cannot be accurately reflected, and the model precision of the final BIM modeling is insufficient. Disclosure of Invention In order to solve the technical problem of insufficient model precision of BIM modeling in the prior art, the invention aims to provide a building exterior surface model rapid construction method based on BIM technology, and the adopted technical scheme is as follows: constructing a first triangular mesh model based on building exterior surface data, wherein the first triangular mesh model is a model formed by splicing a plurality of triangles and used for representing the shape of the building exterior surface; calculating a first folding cost of each side of each triangle in the first triangular mesh model based on a secondary error measurement method; Correcting the first folding price of each side based on the first inhibition factor of each side and/or the second inhibition factor of each side to obtain a second folding cost of each side, wherein the first inhibition factor is used for inhibiting the folding cost of the high-detail-density region, and the second inhibition factor is used for inhibiting the folding cost of the high-shape change region; And simplifying the edges in the first triangular mesh model based on the second folding cost of each edge to obtain a second triangular mesh model. As one possible implementation manner, the method further comprises the steps of calculating average areas of adjacent triangles of two end points of the target edge, wherein each adjacent triangle refers to a triangle taking one of the two end points of the target edge as a triangle vertex, the target edge is any one side of a first triangular mesh model, calculating average values of average areas of adjacent triangles of the two end points, and calculating a first inhibition factor of the target edge based on the average values of the average areas, wherein the first inhibition factor of the target edge is inversely related to the average areas of the adjacent triangles. As one possible implementation, the method further includes determining a first inhibitor adjustment hyper-parameter, calculating a ratio of the first inhibitor adjustment hyper-parameter to an average of the average areas, and taking a sum of the ratio and a first preset value as the first inhibitor. As a possible implementation manner, the method further comprises the steps of calculating curvature characteristic values of two endpoints of the target edge, wherein the curvature characteristic values are used for representing the average change degree of the surface where the endpoints are located, the target edge is any one edge in the first triangular mesh model, and based on the maximum value in the curvature characteristic values of the two endpoints, a second inhibition factor of the target edge is calculated, and the second inhibition factor is positively related to the maximum value. As a possible implementation manner, the method further comprises the steps of calculating unit normal vectors of each adjacent triangle of the endpoint, multiplying the unit normal vectors of each adjacent triangle by the area to obtain a weighted nor