19 results about "Triangulated irregular network" patented technology

The invention discloses a high-precision DEM construction method based on a point cloud model. The method comprises the following steps: step 1, performing grid division on urban point cloud data, dynamically adjusting the grid size and the neighborhood range based on a weighted gradient value, and calculating the weighted gradient value through the height difference and the distance between the lowest points of a central grid and a neighborhood grid; 2, clustering the urban point clouds by using DBSCAN (Density Based Spatial Clustering of Applications with Noise) and combining the features of color, intensity and texture of the point clouds; 3, taking the extracted ground feature line as a constraint during point cloud filtering, and determining the boundary of a ground point and a non-ground point; step 4, based on the ground feature line constraint in the step 3, executing multi-scale adaptive filtering, and removing non-ground points; 5, taking the extracted ground feature line as a constraint during point cloud filtering, and determining the boundary of a ground point and a non-ground point; and step 6, aiming at different partitions, respectively using a nearest neighbor interpolation up-sampling algorithm to construct a TIN (Triangulated Irregular Network) method to construct an urban high-precision DEM (Digital Elevation Model).

The invention discloses a refined fourth-century three-dimensional geological modeling integration method which comprises the steps that basic geological data and drilling data of a research area are acquired, and the basic geological data comprise bedrock geological data and fourth-century geological data; the drilling data is modeled by a triangulated irregular network, and the basic unit of the triangulated irregular network is GTP; performing standardization processing on the drilling data; carrying out fourth stratigraphic division on the research area according to the basic geological data; dEMs of stratum interfaces are sequentially established from the earth surface to the underground according to the drilling data, sewing processing is conducted on the adjacent DEMs belonging to the same stratum, and a three-dimensional stratum model based on the multiple layers of DEMs is formed; dividing the GTP into TEN, and according to the three-dimensional stratum model based on the multilayer DEM, taking the TEN as a basic voxel, and constructing a fourth-century three-dimensional geologic model based on MD-GTP-TEN; the model constructed by the invention can express the geologic body more accurately and perform spatial analysis more efficiently.

The invention discloses a flood dynamic display method and device, equipment, a medium and a product. The method comprises the steps of performing grid reconstruction on irregular quadrilateral grid data at a plurality of moments based on a triangulated irregular network algorithm, and generating first triangular grid data at the plurality of moments; extracting a target quadrilateral grid from the irregular quadrilateral grid data at multiple moments; determining second triangular mesh data at multiple moments corresponding to the target quadrilateral mesh in the first triangular mesh data at multiple moments; constructing an index structure of the second triangular mesh data based on the index identifier, the first mapping relationship and the second mapping relationship; based on the second triangular mesh data and the index structure, generating a to-be-rendered dynamic water surface data set; and based on a time sequence and a multi-normal superposition rendering technology based on a graphic interface, generating visual data representing dynamic changes of the water surface. In this way, the visualization effect and performance of flood routing simulation are improved.

The invention provides a reservoir sediment modeling method based on multi-time-sequence multi-beam sounding point cloud data, and relates to the field of reservoir sediment monitoring and modeling, and the method comprises the steps: constructing a reservoir area space grid skeleton model, and collecting multi-time-sequence multi-beam point cloud data and corresponding hydrological auxiliary data; performing space division by adopting an adaptive tile subdivision method, generating multi-level point cloud tiles by adopting a feature point downsampling method, and establishing a three-dimensional composite index; the indexed multi-level point cloud tile set is processed through an anisotropic ICP registration method, and a point cloud tile set of multi-time-sequence registration is obtained; establishing an initial triangulated irregular network sediment model, carrying out differentiated partitioning by utilizing historical hydrological auxiliary data, and carrying out dynamic updating based on a partitioning state to obtain a dynamic reservoir sediment model; and S5, calculating to obtain deposition parameters, and mapping the deposition by adopting a three-dimensional engine to obtain an interactive three-dimensional dynamic deposition situation map. According to the invention, high-precision dynamic visualization of the reservoir sediment deposition process is realized.

The present application relates to the technical field of visual domain analysis of digital elevation model, and particularly relates to a DEM visual domain analysis method and system based on volume shadow, which comprises the following steps: S1, obtaining digital elevation model DEM data and user input viewpoint parameters, and constructing a regular triangulated irregular network model based on the DEM data; S2, calculating the yin and yang properties of each triangular face based on the viewpoint parameters, and determining the shadow edge according to the yin and yang properties of adjacent triangular faces and the horizontal distance to the viewpoint. In the present application, the DEM visual domain analysis problem is converted into a volume shadow problem with the viewpoint equal to the light source, and the interpolation processing of the terrain by the DEM data and the GIS platform is neat and standard, which simplifies the calculation related to the volume shadow, realizes the precision of the accurate algorithm, approaches the operation speed of the approximate algorithm, and can consider the inclined surface generated by the interpolation processing of the terrain.

The application discloses a land surveying method and device based on multi-source data fusion, and relates to the technical field of surveying, which comprises the following steps: collecting three-dimensional geodetic coordinate data and three-dimensional space point cloud data, obtaining starting three-dimensional coordinate and ending three-dimensional coordinate of surveying, constructing a triangulated irregular network (TIN) terrain model and a shortest path search model on the ground, searching for a starting node and a target node in a weighted undirected graph, calculating the shortest path on the ground and the ground distance, rendering the TIN terrain model to draw the shortest path on the ground, and setting through points and forbidden areas to update the shortest path on the ground and the ground distance. The application breaks through the dependence of traditional land surveying on the line-of-sight condition by fusing multi-source data and constructing continuous digital terrain, intelligently calculates and visualizes the shortest path on the ground, avoids the error accumulation of manual segmented operation, provides interactive path replanning capability, and significantly improves the accuracy, efficiency and scientific nature of planning and decision-making of ground surveying under complex terrain.

The invention discloses a coordinate system conversion method and system based on a triangulated irregular network, and belongs to the technical field of GIS. The method comprises the following steps: respectively acquiring coordinate values of a reference point in a conversion area under a source coordinate system and a target coordinate system; establishing an irregular triangulation network according to a Delaunay triangulation rule by taking the coordinate value of the reference point in the source coordinate system or the target coordinate system as a vertex; calculating local conversion parameters on three sides of each triangle in the triangulated irregular network; calculating a local conversion parameter of any point in each triangle by using the local conversion parameters on the three sides of each triangle and adopting a triangle interpolation algorithm; and performing conversion between a source coordinate system and a target coordinate system on the coordinate points in the conversion area according to the local conversion parameters of any point in each triangle. The method is high in processing efficiency, small in conversion error and better in applicability, and can be suitable for mass coordinate conversion.

The invention provides a three-dimensional model construction method and system for topographic survey, and belongs to the technical field of model construction, and the method comprises the steps: segmenting a satellite image of a target survey region based on the topographic complexity, and obtaining a complex topographic region and an open topographic region; acquiring laser scanning data of the complex terrain area and low-altitude image data of the open terrain area; performing data fusion on the laser scanning data and the low-altitude image data to obtain a target data set corresponding to the target survey area; constructing a regular grid model corresponding to the target survey area based on the target data set; constructing an irregular triangular grid model corresponding to the target surveying area based on the laser scanning data; and fusing the regular grid model and the irregular triangular grid model to obtain a three-dimensional model of the target surveying area. According to the three-dimensional model construction method and system for topographic survey provided by the invention, the modeling precision can be improved.

The invention discloses a point cloud data-based urban rainfall flood simulation-oriented drainage ditch modeling method, which belongs to the technical field of urban hydrological modeling, and comprises the following steps of: extracting point cloud data of ditch bottom points to construct an irregular triangulation network model of a drainage ditch; judging whether the triangulated irregular network model of the drainage ditch contains the geometric center of the point cloud data of the ditch bottom point or not; if not, separating the inner edge and the outer edge of the drainage ditch, and then extracting the edge point of the drainage ditch by using a double-ray method; if so, extracting edge points of the drainage ditch by using a direct ray method; for a straight edge of the drainage ditch, fitting edge points of the drainage ditch by using a linear interpolation method; for the curved edge of the drainage ditch, fitting the edge of the drainage ditch by using a second-order B-spline curve; and modeling according to the drainage ditch vector edge and the drainage ditch internal point set to generate a drainage ditch model. According to the method, the problems that a traditional modeling method is large in simulation error, complex water flow characteristics are lacked, and the dynamic characteristics of water flow convergence, overflow and drainage cannot be truly restored are solved.

The invention provides a three-dimensional gradient adjustment method based on a triangulation network normal vector, and relates to the technical field of computer aided design, and the method comprises the following steps: S1, obtaining a triangulation network vertex; s2, generating a triangulation network DEM model; s3, calculating a normal vector of each triangulation network; s4, calculating a slope value of each triangulation network; s5, gradient critical analysis; s6, screening the triangulation network to be adjusted; and S7, adjusting the vertex elevation of the triangulation network. According to the method, regression calculation is carried out through slope analysis and adjustment based on triangulation network corner control, rationality verification is carried out with the assistance of slope rendering and slope screening methods, the automation degree is high, the visualization effect is good, efficient analysis and calculation adjustment of large-range, large-data-volume and complex terrain slopes can be achieved with the assistance of a computer, and the method is suitable for popularization and application. The design precision and efficiency are greatly improved, and the labor cost in the design process is reduced.

The invention relates to the field of computer simulation and virtual reality, in particular to a simulation war game deduction situation display technology based on a three-dimensional inclined terrain. The simulation war game deduction situation display technology based on the three-dimensional inclined terrain comprises the following steps: a, a terrain data loading and processing step: obtaining a digital elevation model or triangulated irregular network data of a battlefield area, and processing the digital elevation model or triangulated irregular network data into a three-dimensional gridding terrain model for real-time calculation, according to the method, the three-dimensional gridding terrain model is deeply integrated into the deduction kernel and directly used for resolving the intervisibility field based on real terrain shielding in real time, and the problem that the terrain and deduction logic are disjointed in the traditional technology is fundamentally solved by combining the firing range limited by the pitch angle of a weapon and the maneuverability influenced by the gradient, so that the method is suitable for the large-scale industrial application. And the accuracy and authenticity of tactical judgment and deduction results are remarkably improved.

The invention relates to the technical field of data acquisition, in particular to an ecological park topographic feature high-precision acquisition method based on an unmanned aerial vehicle, and the method comprises the steps: collecting high-precision topographic data in a park through arranging a two-stage RTK-GNSS control network and combining an aerial survey technology that an unmanned aerial vehicle carries an oblique photography camera; the first-level control points are arranged in a terrain stable area, and the second-level control points are arranged in an encrypted mode according to complex terrains such as side slopes and depressions; the unmanned aerial vehicle performs data acquisition in a simulated flight mode, and ensures comprehensive coverage of images through multi-angle supplementary shooting; the point cloud data is accurately registered through the ICP algorithm with the weight, and the accuracy of key feature points is effectively improved; the generated triangulated irregular network (TIN) model is further used for terrain modeling to ensure the precision and continuity of a key area; and finally, performing precision verification on the three-dimensional scene through the reserved check points to ensure that the plane position error is not greater than + / -2cm and the elevation error is not greater than + / -3cm.

The invention relates to a spoil ground three-dimensional form modeling method based on time sequence LiDAR data. The method comprises the steps that spoil ground terrain collaborative data collection is carried out by using unmanned aerial vehicle oblique photogrammetry and laser radar technologies; importing the image data into three-dimensional modeling software to generate an orthoimage, calculating an exterior orientation element and an interior orientation element of the image through aerial triangulation, and establishing a geometrical relationship between the images; dense matching is carried out by adopting a multi-view stereo matching algorithm, and point cloud optimization is realized by fusing statistical filtering and radius filtering; adopting a progressive triangulation network encryption algorithm to construct and optimize the density and the structure of the initial irregular triangulation network; and carrying out texture mapping, image registration and seam optimization on the optimized triangulated irregular network to realize the construction of a live-action three-dimensional model. According to the scheme provided by the invention, the details of the spoil site can be effectively reserved, the features are accurately restored, the visual authenticity of the three-dimensional model is improved, and the actual condition of the spoil site is accurately reflected.

The application provides a three-dimensional model construction method and system for topographic survey, and belongs to the technical field of model construction. The method comprises the following steps: segmenting satellite images of a target survey area based on the complexity of the terrain to obtain complex terrain areas and open terrain areas; obtaining laser scanning data of the complex terrain areas and low-altitude image data of the open terrain areas; fusing the laser scanning data and the low-altitude image data to obtain a target data set corresponding to the target survey area; constructing a regular grid model corresponding to the target survey area based on the target data set; constructing an irregular triangular grid model corresponding to the target survey area based on the laser scanning data; and fusing the regular grid model and the irregular triangular grid model to obtain a three-dimensional model of the target survey area. The three-dimensional model construction method and system for topographic survey can improve the modeling accuracy.

The invention relates to the technical field of digital elevation model processing, in particular to a confidence-based mountain city staggered-floor building DEM optimization method and system, and the method comprises the steps: carrying out the grouping frequency number statistics of a buffer region, generating a frequency number histogram, recognizing a significant wave crest in the frequency number histogram, calculating a staggered-floor confidence score, and carrying out the calculation of the frequency number histogram according to the significant wave crest and the staggered-floor confidence score. The house type is judged, if the house type is a common house, the minimum elevation value in the significant wave crests is taken as the terrace height, and if the house type is a split-level building, a binding relation set of the house side edge and the terrace height is established; and taking the house contour line as a terrain fracture line, generating a constraint point in combination with the terrace height, and generating a DEM by adopting a constraint triangulated irregular network method. According to the scheme, manual intervention is not needed, the split-level building in the mountain city can be automatically, effectively and accurately recognized, high-fidelity modeling is conducted on the multi-level terrace height of the split-level building, and therefore the high-precision DEM conforming to semantic authenticity is generated, and the precision and authenticity of the DEM are improved.

The invention relates to the technical field of geographic information processing, and discloses a complex terrain multi-resolution modeling method based on LOD and triangulation network folding, which comprises the following steps: firstly, constructing an irregular triangulation network and extracting a landform skeleton network, and then carrying out spatial partitioning according to the sampling distribution density and the elevation change rate; for each block, calculating an entanglement sensitivity index representing the change response of the ridge-valley space compactness along with the analysis granularity, and constructing a comprehensive evaluation system comprising a geometric deviation component and a skeleton structure retention component according to the entanglement sensitivity index; and finally, controlled grid folding optimization is executed based on the evaluation system, and weighting parameterization stitching is performed on adjacent block boundaries by using the sensitivity indexes. According to the method, the key landform skeleton in the complex mountain scene can be accurately sensed and reserved, structural topology errors in the simplification process are avoided, and the spatial structure consistency and splicing smoothness of the multi-resolution model under different levels are ensured.

The application relates to the technical field of geographic information processing, and discloses a complex terrain multi-resolution modeling method based on LOD and triangulation net folding, which comprises the following steps: firstly, constructing an irregular triangulation net and extracting a landform skeleton network, then carrying out spatial block division according to sampling distribution density and elevation change rate; for each block, calculating an entanglement sensitivity index representing the response of ridge-valley spatial tightness to the change of analysis granularity, and constructing a comprehensive evaluation system containing a geometric deviation component and a skeleton structure maintaining component according to the index; finally, performing controlled grid folding optimization based on the evaluation system, and performing weighted parameterized suture on the boundaries of adjacent blocks by using the above sensitivity index. The application can accurately perceive and retain the key landform skeleton in a complex mountainous scene, avoid structural topological errors in the simplification process, and ensure the spatial structure consistency and splicing smoothness of the multi-resolution model at different levels.

The invention relates to the technical field of visual field analysis of a digital elevation model, in particular to a DEM (Digital Elevation Model) intervisibility field analysis method and system based on volume shadow, and the method comprises the following steps: S1, obtaining DEM data and viewpoint parameters input by a user, and constructing a regular triangulation network model based on the DEM data; and S2, calculating the yin and yang attributes of each triangular surface based on the viewpoint parameters, and determining a shielded edge according to the yin and yang attributes of the adjacent triangular surfaces and the horizontal distance to the viewpoint. According to the method, the DEM intervisibility field analysis problem is converted into the problem that the viewpoint is equal to the volume shadow of the light source, the feature that interpolation processing of DEM data and a GIS platform on the terrain is neat and standard is utilized, calculation related to the volume shadow is simplified, the precision of an accurate algorithm is achieved, the operation speed is close to that of an approximation algorithm, and the calculation efficiency is improved. And meanwhile, an inclined plane generated by terrain interpolation processing can be considered.

The invention provides a method for updating the depth of a channel and a storage medium, and the method comprises the steps: firstly carrying a depth finder on a ship, and collecting discrete new depth sounding points containing coordinates, a water depth value and a timestamp in real time; then generating a sounding surface by using a concave shell boundary extraction algorithm and a triangulated irregular network interpolation algorithm; uniformly converting the newly generated sounding surface and the old water depth surface into a point set form for projection registration to obtain a registration point pair corresponding to the space; the registration point pairs are processed through a Huber loss function and an iterative reweighted least square algorithm, and the real-time draught depth of the depth finder is obtained through inversion; and finally, superposing the draft obtained by inversion with the sounding surface, and outputting a new version of water depth surface. According to the method, traditional periodic off-line water depth survey is converted into on-ship instant on-line updating, the problem of water depth data lag caused by water level dynamic change and terrain deposition is effectively solved, and the current trend of data is remarkably improved.