9 results about "Quadratic error" patented technology

The invention discloses a lightweight method and system for a highway engineering three-dimensional live-action model and a medium, and relates to the technical field of three-dimensional live-action modeling. The method comprises the following steps: firstly, carrying out engineering semantic segmentation on an input three-dimensional grid model, and extracting design parameters in a BIM / GIS (Basic Information Model / Geographic Information System); then, constructing a multi-level constraint model fusing semantic constraints, engineering precision constraints and design parameter constraints; and finally, carrying out iterative simplification under the guidance and limitation of the multi-level constraint model by adopting an improved quadratic error measurement algorithm. The method solves the problems of semantic information loss, out-of-control local precision and disjunction with design intention when a traditional pure geometric simplification method is applied to highway engineering, and can intelligently reserve key engineering characteristics, control geometric errors and fit a design form while ensuring that the data size of the model is greatly reduced. And a high-quality lightweight model suitable for professional analysis and application is generated.

Mesh simplification reduces the complexity of 3D objects while maintaining visual fidelity. While there are effective techniques for mesh simplification for simple meshes, in actual use cases it may be difficult to simplify more complicated meshes. A technical solution retrieves an initial mesh (e.g. a triangle mesh) and constructs an edge list including physical and virtual edges for the initial mesh. The initial mesh is then decimated by iteratively collapsing the edges, prioritized based on a modified quadric error metric that may combine a memory edge quadric error and a memoryless area quadric error. The technical solution may maintain a correspondence map during the decimating and use it to perform texture transfer after simplification based on the correspondence map.

The present invention relates to the technical field of three-dimensional visualization, and discloses a method and system for controlling three-dimensional visualization operations for intelligent roadbed construction. The method comprises: collecting multi-source roadbed data, performing position correction on the multi-source roadbed data using an improved SLAM algorithm; performing multi-source fusion on the position-corrected multi-source roadbed data to obtain roadbed fusion data; constructing a three-dimensional model of the roadbed construction based on the roadbed fusion data; and performing lightweight processing and dynamic operation rendering on the three-dimensional model of the roadbed construction using a quadratic error measure grid simplification algorithm. The present invention calculates the multi-dimensional feature entropy of different roadbed areas, selects roadbed areas with complex terrain for multiple resampling, improves the accuracy of three-dimensional modeling of complex roadbed areas, merges triangle face vertices in the three-dimensional model of the roadbed construction based on their error matrix, realizes lightweight processing of the three-dimensional model of the roadbed construction, and performs real-time three-dimensional visualization of the roadbed construction operation process.

The invention relates to the technical field of three-dimensional modeling, in particular to a building outer surface model rapid construction method based on a BIM technology, and is used for solving the technical problem of insufficient model precision of BIM modeling in the prior art. The method comprises the following steps: constructing a first triangular mesh model based on building outer surface data; calculating a first folding cost of each edge of each triangle in the first triangular mesh model based on a quadratic error measurement method; correcting the first folding cost of each edge based on the first inhibition factor of each edge and / or the second inhibition factor of each edge to obtain the second folding cost of each edge; 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; 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.

The application provides a three-dimensional mesh model simplification method, device, equipment and medium, and relates to the technical field of model simplification. The method comprises the following steps: adopting a region growing algorithm, determining a growing region according to a free selection region and geometric topology information of a three-dimensional mesh model; determining an error matrix of each triangular facet in the growing region according to the geometric topology information, and determining the sum of quadratic errors of all associated triangular facets according to the error matrix; determining a vertex folding cost and a new vertex according to the sum of quadratic errors, determining an edge folding cost and performing priority sorting according to the new vertex; and performing edge simplification folding according to the sorted edge folding cost, so as to obtain simplified vertices and corresponding simplified geometric topology information. The application can improve the simplification effect.

The invention provides a three-dimensional grid model simplification method and device, equipment and a medium, and relates to the technical field of model simplification, and the method comprises the steps: employing a region growth algorithm, and determining a growth region according to a free selection region and geometric topology information of a three-dimensional grid model; determining an error matrix of each triangular patch in the growth area according to the geometric topology information, and determining the sum of secondary errors of all associated triangular patches according to the error matrix; according to the sum of the secondary errors, determining a vertex folding cost and a new vertex, and according to the new vertex, determining an edge folding cost and performing priority ranking; and performing edge simplified folding according to the sorted edge folding cost to obtain simplified vertexes and corresponding simplified geometric topology information. The invention can improve the simplification effect.

The present invention discloses a method, system, device and storage medium for supporting lightweight processing and lossless compression of multi-source three-dimensional models, which relates to the field of three-dimensional technology, including: performing format compatibility check on the imported three-dimensional model, and analyzing the geometric structure, texture characteristics and material properties of the model; using a quadratic error metric algorithm and edge folding to simplify the geometric structure of the three-dimensional model, optimizing the simplified model through edge segmentation operations to obtain a lightweight model; using a data compression algorithm to compress the geometric data of the lightweight model, and compressing the texture data through predictive coding to complete the lossless compression of the three-dimensional model. The method of the present invention significantly improves the loading speed and real-time rendering efficiency by reducing the file size of the three-dimensional model and optimizing the texture compression algorithm. The lossless compression technology ensures that high-quality visual effects are maintained during the lightweight process, and the lightweight model reduces storage space requirements and also reduces energy consumption by reducing data transmission and processing.

The application relates to the technical field of three-dimensional modeling, in particular to a building outer surface model rapid construction method based on BIM technology, which is used to solve the technical problem of insufficient model precision in BIM modeling in the prior art. The method comprises the following steps: constructing a first triangular mesh model based on building outer surface data; calculating a first folding cost of each edge of each triangle in the first triangular mesh model based on a quadratic error measurement method; correcting the first folding cost of each edge based on a first inhibition factor of each edge and / or a second inhibition factor of each edge to obtain a second folding cost of each edge; the first inhibition factor is used to inhibit the folding cost of a high-detail-density area, and the second inhibition factor is used to inhibit the folding cost of a high-shape-change area; and performing simplification processing on the edges in the first triangular mesh model based on the second folding cost of each edge to obtain a second triangular mesh model.

The application discloses a triangle mesh graph neural network simplification method, and belongs to the technical field of computer deep learning, which acquires a triangle mesh model to be simplified and constructs a graph structure with vertices as nodes and undirected edges based on the topological relation of triangular facets as graph edges; the nodes are subjected to feature initialization, and geometric, topological and Laplacian position coding information is fused; a multi-scale adjacency relation containing 1st-order adjacent edges and 2nd-order adjacent edges is constructed; the node features and the multi-scale adjacency relation are input into a graph neural network, message passing and feature aggregation are completed in different neighborhoods based on a graph convolution network, and edge importance probability is predicted; the edge geometric structure importance is integrated into a simplification process, and the key feature protection effect is improved; the geometric structure features extracted by deep learning are combined with a classical quadratic error measurement algorithm, and the edge collapse cost is dynamically scaled, so that the number of mesh facets is greatly reduced, and the geometric features and the topological structure of the model are effectively maintained.