[0058] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, not all of the embodiments. . Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work shall fall within the protection scope of the present invention.
[0059] The application scenarios described in the embodiments of the present invention are to illustrate the technical solutions of the embodiments of the present invention more clearly, and do not constitute a limitation on the technical solutions provided by the embodiments of the present invention. Those of ordinary skill in the art will know that as new application scenarios change It appears that the technical solutions provided by the embodiments of the present invention are equally applicable to similar technical problems. Wherein, in the description of the present invention, unless otherwise specified, "multiple" means two or more.
[0060] A method for constructing a simulated city model in an embodiment of the present invention, such as figure 1 As shown, including the following steps:
[0061] Step S10: Perform a three-dimensional reconstruction of the urban outdoor building based on the oblique photogrammetry technology to obtain an outdoor model of the building;
[0062] Step S20, acquiring an indoor model of a city building based on BIM technology;
[0063] Step S30, fusing the outdoor model of the building with the indoor model to obtain a three-dimensional simulation building model that is integrated between indoor and outdoor;
[0064] Step S40, fusing the simulated building model and the ground surface model to obtain a simulated city model; wherein the ground surface model includes ground elevation information, road coordinate information, water system coordinate information, vegetation coordinate information, etc., but does not include building information.
[0065] Among them, such as figure 2 As shown, in step S10, using the tilt camera measurement technology to obtain an outdoor model of a building includes the following steps:
[0066] Step S101: Obtain UAV remote sensing images
[0067] The quality of building a three-dimensional city model based on oblique photogrammetry largely depends on the quality of data collection. The acquisition of UAV remote sensing images mainly includes four steps: camera calibration, route planning, image control point measurement and UAV aerial survey. Among them, the camera calibration is: in the image measurement process and machine vision applications, in order to determine the relationship between the three-dimensional geometric position of a point on the surface of a space object and its corresponding point in the image, the geometric model of the camera imaging must be established. These geometric models The parameters are the camera parameters; under most conditions, these parameters must be obtained through experiments and calculations. This process of solving the parameters is called camera calibration (or camera calibration).
[0068] Step S102, data preprocessing
[0069] Data preprocessing is mainly to prepare for outdoor modeling, including image uniform light processing and POS (position and orientation system) data acquisition.
[0070] Due to the influence of factors such as light changes, different sensors, and different acquisition times, the images acquired by drones generally have color imbalances between the same photo or different photos. In order to ensure the uniform light color of the aerial photos, the photos need to be uniformed and uniformed.
[0071] POS data is the corresponding position and attitude data of the image obtained by the drone, and the format of the data is related to the specific drone. For the POS data directly written into the image, the post-modeling software can be directly read. For POS files and images that need to be input into the post-modeling software independently, generally need to use the drone software to convert into a fixed format image control point data file .
[0072] Step S103, aerial triangulation and control point calculation
[0073] The essence of aerial triangulation in this method is to measure the coordinates of the image points in the overlapping area of the image, combine with the coordinates of the field image control points, and calculate the external orientation elements of the image according to the collection relationship between the image and the ground object. The coordinates of the encryption point. The process mainly adopts the integrated method of image control point image correlation and aerial triangulation. This method can avoid the problem of excessive workload of establishing all image control points and most of the image related files, and can also reduce the difficulty of thorn points while ensuring accuracy .
[0074] In this method, the aerial triangulation at any scale and azimuth is performed first without adding image control points, which can initially check the field data results. Secondly, select 3 image control points among all image control points, and for each image control point, select 2 corresponding images with clear image control points, complete the association of image control points and images, and perform aerial triangle under non-fixed control points Measure and then perform precise correlation to ensure that each lens has at least 3 consecutive image punctures and 3 photos for each control point to complete aerial triangulation under a fixed control point. Finally, refine the thorn points according to the adjustment results, and perform aerial triangulation again until all control points meet the accuracy requirements.
[0075] Step S104, 3D outdoor model establishment
[0076] After obtaining the control point data, a 3D model can be established. Utilize the image dense matching solution provided by the ContextCapture platform to reconstruct the image with ultra-high density point cloud Digital Surface Model (DSM), and parallel GPU acceleration, which greatly improves the efficiency, such as image 3 Shown.
[0077] Step S105, texture matching and refinement processing
[0078] Texture matching and refinement processing is a technique for adding satellite images to the surface of a three-dimensional model, which can provide rich surface detail information without increasing the complexity of the surface of the object. Using automatic texture mapping technology, matching the corresponding image data on the ultra-high-density point cloud digital surface model (DSM) to form a more realistic three-dimensional building model.
[0079] In addition, the 3D model based on oblique photogrammetry images using related software (such as ContextCapture), due to insufficient near-surface images, often leads to problems such as model adhesion and texture loss. DpModeler modeling software can be used to repair and refine.
[0080] Among them, such as Figure 4 As shown, the construction of an indoor model of a city building based on BIM technology in step S20 includes the following steps:
[0081] Step S201, establishment of building site and site components
[0082] The layout of the building site is related to factors such as building floor and topographic surface. The terrain surface can be set up in Revit (a kind of BIM modeling software) by importing CAD contour lines, or by reading elevation files.
[0083] In the embodiment of the present invention, DSM (Digital Surface Model) information is extracted according to the outdoor model creation process and imported into the CAD file to form the corresponding contour map. The topographic surface of the project can be obtained in Revit information.
[0084] Step S202, establishment of elevation and grid
[0085] The positioning information in the building is determined by the grid and elevation. The role of the grid is equivalent to the coordinate system of each plane, and the elevation corresponds to the height of the building plane. In Revit, elevation and grid together constitute a grid positioning system, which is the basis for the establishment of later components. Usually each level in a building corresponds to a floor plan. Generally, when the BIM data model is imported into Revit, the elevation part is displayed normally and does not need to be rebuilt. If the elevation line is too long to observe, you can adjust the elevation line length horizontally through the elevation view.
[0086] Among them, the elevation and grid, as well as the internal wall structure and pipeline structure in the following design, can be obtained from the data (such as drawing information, design electronic document information, etc.) during the construction of the building, or can be obtained by measurement.
[0087] Step S203, structural design
[0088] When creating a BIM model, select the required types from different families according to the needs, and adjust its parameters to meet the needs. There are three types of walls involved in the production: basic wall, laminated wall and curtain wall. Different families are called and the parameters are set for drawing. In addition to the wall, the structural composition of the model also includes columns, beams, floor slabs, etc., which are the same as the wall settings. The corresponding families are respectively called and drawn to the specified location according to the drawing.
[0089] Step S204, pipe network modeling
[0090] Pipeline construction needs to re-establish the model, call the mechanical model, and then call the pipeline template in the system tab to draw.
[0091] When drawing a pipeline using Revit modeling software, it is divided into three steps: selecting the system, selecting the pipe diameter (material, fittings, etc.), and determining the height. Click on the bottom of the pipe property bar and select the system type as "circulating water supply", then click edit type, select "piping system configuration", general pipe fittings, size ranges, and pipe fitting types are all set here. For mechanical templates, you can also draw pipes Elbows, tees and other components. After the simple drawing is completed, the height and diameter of the pipe can be changed according to the needs of the project. The specific operation is to click the pipe to highlight it, move the mouse to the end of the pipe, right-click and click "Draw Pipe", re-enter the pipe diameter and height, and then Continue drawing, click on the 3D view, the pipe will generate a riser. After the pipeline is drawn, the pipelines of different systems can be distinguished according to specific needs, and material colors can be added.
[0092] Step S205, building internal component modeling
[0093] The internal components of a building contain indoor items. Building internal structure modeling usually divides indoor internal components into furniture decoration and office equipment. The furniture decoration includes: TV, refrigerator, water dispenser, aquarium, bonsai, cabinet, etc.; office equipment includes: desk, office chair, conference table, etc. The general shape of the interior components is not very regular, the size is different, the complexity is various, and the family file provided by the software can be used for rapid modeling, and the physical model can also be made according to the required size.
[0094] Step S206, rendering of the 3D model
[0095] Complete the model establishment in Revit, and render the model in a three-dimensional view to obtain a visual effect. Set the model display detail level to "Fine" and the rendering effect to the best. After the rendering is completed, the interior model of the building is obtained.
[0096] It should be noted that the construction of the indoor model can be based on the BIM model during the construction of the building, or can be constructed based on various drawing data during the construction of the building.
[0097] Among them, such as Figure 5 As shown, the process of fusing the outdoor model and the indoor model of the building in step S30 is as follows:
[0098] Step S301, preliminary integration of outdoor model and indoor model
[0099] Select an outdoor architectural feature point P as the origin of the relative coordinate system on the 3D outdoor model of the building obtained by oblique photogrammetry, import the 3D outdoor model into 3DMax software, and adjust the position of the model so that the outdoor architectural feature point P and the coordinates The system origin coincides.
[0100] Select the indoor model obtained based on BIM modeling, calculate the relative coordinates of multiple indoor architectural feature points of the indoor model with respect to the outdoor architectural feature point P, import the indoor model into the 3DMax software, and adjust the position according to the relative coordinates so that The indoor model is roughly the same space as the outdoor model.
[0101] Use 3DMax software to adjust the attitude parameters (Rotation) and scale parameters (Scale) of the indoor model to ensure that the indoor model is consistent with the outdoor model. The outdoor model and the indoor model of all buildings are integrated in turn, and the integrated simulation buildings The model is merged and exported to fbx format.
[0102] Step S302, the single processing of the simulation building model
[0103] The single processing of the simulation building model is to separate the wall of the simulation building model from the ground surface where the simulation building model is located, and separately obtain the bottom vector information and wall surface vector information of each simulation building model. Through the singulation processing of the simulation building model, more accurate vector information of the outdoor building model can be obtained, so that the outdoor model and the indoor model can be further refined and fused to obtain a better fusion effect. In this implementation manner, DpModeler and 3DMax can be used to link the simulation building model into a single unit. Specifically include the following steps:
[0104] Step S302a. Use DpModeler and 3DMax linkage plug-in to load the simulated building model after preliminary fusion; collect the building feature points that need to be singulated in DpModeler and disperse the outdoor model to obtain various wall surface vector parameters, and obtain the building’s Bottom surface vector parameters;
[0105] Among them, the wall surface vector information is obtained in the following way: the wall surface feature points of each individualized building model are drawn in turn, and the wall surface feature points are converted into closed surface vector parameters using DpModeler. The bottom surface vector parameters of the building are obtained in the following way: the bottom surface feature points of each single building model are drawn in turn, and the bottom surface feature points are converted into closed surface vectors using DpModeler. After completing the wall surface vector parameters and the bottom surface vector parameters, export them respectively.
[0106] Step S302b, call the wall surface vector information correction model in 3DMax, adjust the wall surface position of the outdoor model, and accurately merge the indoor model with the outdoor model;
[0107] Step S302c, refine the structure of the model in 3DMax, and modify the special different surface;
[0108] Step S302d: Use the DpModeler and 3DMax linkage plug-in to complete the automatic texture mapping, and check and modify the abnormal texture.
[0109] Among them, such as Image 6 As shown, the steps of fusing the simulated building model and the ground surface model in step S40 are as follows:
[0110] Step S401, construct a surface model
[0111] According to the needs of 3D reconstruction of the city, the necessary vector information of the surface model is obtained according to the fusion city model. The vector information of the surface model includes ground elevation information, road coordinate information, water system coordinate information, and vegetation coordinate information.
[0112] Among them, the VBS3 military simulation engine is used to construct the ground based on the ground elevation information; the rivers and lakes are constructed based on the water system vector information; the road network model is constructed based on the vector information such as road coordinates and the fusion model road material; based on the vegetation vector information Construction of vegetation models in gardens and woodlands.
[0113] Step S402, extract the digital elevation model
[0114] Select the surface elevation points at a certain sampling interval from the ground surface of the simulation building model, establish a triangulation network and generate a digital elevation model according to the selected elevation points;
[0115] Step S403, fusion of the simulation building model and the ground model
[0116] The VBS3 military simulation engine retrieves the bottom vector information obtained in step S302a, and at the same time retrieves the surface model data, and locates the simulated building model to the specific position of the surface model; the VBS3 military simulation engine retrieves the digital elevation model obtained according to step S402, and It is integrated with the surface model. The model and vector information of some special structures can be extracted according to needs, such as billboards, factory buildings, power poles, communication poles and other structure information, and integrated into the surface model, and at the same time set the surface attributes, texture parameters and other information to generate a simulated city model . The simulated city model obtained is as Figure 7 Shown.
[0117] In the embodiment of the present invention, the VBS3 military simulation engine is used to complete the three-dimensional modeling of the city. Because the VBS3 simulation platform needs to add surface simulation attributes (such as friction coefficient, adhesion coefficient, muddy degree, elastic coefficient, etc.) during the establishment of the three-dimensional surface model, according to The input requirements of the VBS3 simulation platform require vector information extraction and model singulation operations on the integrated simulation building model, and then use the VBS3 military simulation engine to complete the construction of the simulation city model.
[0118] It should be noted that in this embodiment, the data processing and data conversion are as follows:
[0119] At present, the 3D real scene model acquired based on oblique photogrammetry widely adopts the OSGB data format to facilitate data exchange and rapid visualization of 3D scene data. The general output format of the urban building indoor model generated by Revit based on BIM above is FBX, and data formats such as IFC and RVT can also be output. FBX format is Autodesk's free format that can be used for cross-platform data exchange. It provides a C++ software development platform and API toolkit for users to read and write. OSGB is a default format of OSG and can be loaded directly by OSG. The indoor model built with Revit software can optimize the texture through 3DMax, and the 3DMax plug-in osgExp can be used to convert the 3DMax model into an OSGB file, which can then be loaded by OSG. In the embodiment of the present invention, the integration of the outdoor model obtained by oblique photogrammetry and the indoor model obtained by BIM modeling is the key. First, the radius function and center function in the BoundingSphere class in OSG need to be used to obtain the outdoor model and indoor model size and Center coordinates, and then use the setScale function and setPosition function in the PositionAttitudeTransform class to adjust the size and position to ensure the consistency of the indoor model and the outdoor model. This completes the data fusion of the outdoor model based on oblique photogrammetry and the indoor model based on BIM.
[0120] Based on the same inventive concept, embodiments of the present invention provide a device for constructing a simulated city model, such as Picture 8 As shown, it includes: a processor 81 and a memory 82, wherein the memory 82 stores program code, and when the program code is executed by the processor 81, the processor 81 is caused to perform the following steps:
[0121] The outdoor model of the building obtained by oblique photogrammetry and the indoor model of the building constructed by BIM are merged to obtain a simulated architectural model; wherein, the outdoor model and the indoor model are obtained by combining the coordinates of the outdoor model The data and the coordinate data of the indoor model are placed in the same coordinate system to achieve fusion;
[0122] The simulated building model and the ground surface model are fused to obtain a simulated city model.
[0123] In an embodiment of the present invention, the device is specifically used to realize the integration of the outdoor model and the indoor model in the following manner:
[0124] Establishing a coordinate system based on the coordinate data of the outdoor model, and taking an outdoor building feature point in the outdoor model as the origin of the coordinate system;
[0125] Calculating the relative coordinates of multiple indoor building feature points and the outdoor building feature points in the indoor model;
[0126] The position of the indoor model in the coordinate system is adjusted according to the relative coordinates to realize the fusion of the outdoor model and the indoor model to obtain the simulated building model.
[0127] In an embodiment of the present invention, the device is specifically used to realize the integration of the simulated building model and the ground surface model in the following manner:
[0128] Singulate the simulation building model to obtain the bottom surface vector parameters of the building;
[0129] Acquire the digital elevation model of the simulated building model;
[0130] The bottom surface of the simulated building model and the ground surface of the ground surface model are fused according to the bottom surface vector parameters, and the digital elevation model and the ground surface model are fused to obtain the simulated city model.
[0131] In an embodiment of the present invention, the device is specifically used for, after singulating the simulated building model to obtain the bottom surface vector parameters of the building, compare the digital elevation model with the Before the fusion of the surface model to obtain the simulated city model, it also includes:
[0132] The surface of the simulated building model is modified by using texture automatic mapping technology.
[0133] In an embodiment of the present invention, the device is specifically used to construct an indoor model of the building in the following manner:
[0134] Obtaining a digital surface model of the building according to the outdoor model;
[0135] Building an indoor model on the digital surface model according to the construction information of the building.
[0136] Based on the same inventive concept, the present invention provides an embodiment of a simulation city model construction device, such as Picture 9 Shown, including:
[0137] The first fusion unit 91 combines the outdoor model of the building obtained by oblique photogrammetry with the indoor model of the building constructed by BIM to obtain a simulation building model; wherein, the outdoor model and the indoor model are obtained by combining The coordinate data of the outdoor model and the coordinate data of the indoor model are placed in the same coordinate system to achieve fusion;
[0138] The second fusion unit 92 merges the simulated building model and the ground surface model to obtain a simulated city model.
[0139] Based on the same inventive concept, an embodiment of the present invention provides a storage medium in which program code is stored, and the program code is set to execute the following steps when running:
[0140] The outdoor model of the building obtained by oblique photogrammetry and the indoor model of the building constructed by BIM are merged to obtain a simulated architectural model; wherein, the outdoor model and the indoor model are obtained by combining the coordinates of the outdoor model The data and the coordinate data of the indoor model are placed in the same coordinate system to achieve fusion;
[0141] The simulated building model and the ground surface model are fused to obtain a simulated city model.
[0142] The foregoing describes the present application with reference to block diagrams and/or flowcharts illustrating methods, devices (systems) and/or computer program products according to embodiments of the present application. It should be understood that one block of the block diagram and/or flowchart diagram and a combination of the blocks in the block diagram and/or flowchart diagram can be implemented by computer program instructions. These computer program instructions can be provided to the processor of a general-purpose computer, a special-purpose computer, and/or other programmable data processing devices to produce a machine such that the instructions executed via the computer processor and/or other programmable data processing device create A method to implement the functions/actions specified in the block diagram and/or flowchart block.
[0143] Correspondingly, hardware and/or software (including firmware, resident software, microcode, etc.) can also be used to implement this application. Furthermore, this application may take the form of a computer program product on a computer-usable or computer-readable storage medium, which has a computer-usable or computer-readable program code implemented in the medium to be used by the instruction execution system or Used in conjunction with the instruction execution system. In the context of this application, a computer-usable or computer-readable medium can be any medium that can contain, store, communicate, transmit, or transmit a program for use by an instruction execution system, device, or device, or in combination with an instruction execution system, Device or equipment use.
[0144] Obviously, those skilled in the art can make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. In this way, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.
