Underlying surface body-fitting grid generation method and electronic equipment for high-precision simulation

Abstract

The present invention provides a method and electronic device for generating a body-fitting mesh of an underlying surface for high-precision simulation, the method comprising: determining the building vertex indication data of each building based on the building indication data of each building; generating the initial top surface indication data and the side surface indication data of each building based on the building vertex indication data of each building, and determining the target top surface indication data of each building based on the initial top surface indication data of each building; generating a three-dimensional underlying surface model of a target area based on the target top surface indication data and the side surface indication data of each building; generating an underlying surface body-fitting mesh of the target area based on the underlying surface three-dimensional model, the underlying surface body-fitting mesh supporting the use of diffusion simulation for the target area. The embodiment of the present invention can conveniently generate an underlying surface body-fitting mesh, and improve the generation efficiency of the underlying surface body-fitting mesh.

Description

Technical Field

[0001] The invention relates to the technical field of diffusion simulation, and in particular to a method for generating underlying surface body-fitting grids for high-precision simulation and electronic equipment. Background Art

[0002] As an effective means, numerical simulation technology has been widely used in the study of atmospheric boundary layer and atmospheric aerosol transport and diffusion, and has achieved good results. Among them, studying the diffusion and transport laws of substances (such as aerosols, etc.) under the real underlying surface body-fitting grid is of great significance for the rational allocation of environmental resources in these areas and the design of risk avoidance plans after the occurrence of hazardous substance leakage incidents. The underlying surface body-fitting grid of a region is generated through the underlying surface three-dimensional model of the corresponding region. Based on this, the diffusion simulation of any substance in the target area can be realized based on the small-scale model of Computational Fluid Dynamics (CFD) (i.e., CFD model), but the CFD model usually only supports three-dimensional model data in a fixed format (such as .obj (a 3D (Three Dimensions, three-dimensional) model file format), .stl (a file format for representing triangular meshes), etc.); but the related technology usually uses modeling software such as 3D Max (a three-dimensional animation rendering and production software) to make a three-dimensional model of the underlying surface by manual modeling, that is, the three-dimensional model of the underlying surface is usually made manually, resulting in cumbersome and low efficiency in the operation of generating the underlying surface three-dimensional model, which leads to cumbersome and low efficiency in the operation of generating the underlying surface body-fitting mesh. Based on this, how to conveniently generate the underlying surface body-fitting mesh of the target area to improve the generation efficiency of the underlying surface body-fitting mesh has not yet had a good solution. Summary of the invention

[0003] In view of this, an embodiment of the present invention provides a method and electronic device for generating a body-fitting mesh of an underlying surface for high-precision simulation, so as to solve the problems of cumbersome operation and low efficiency of generating a body-fitting mesh of an underlying surface caused by related technologies; that is, an embodiment of the present invention can conveniently generate a three-dimensional model of the underlying surface of the target area through the target top surface indication data and side surface indication data of each building in the target area, thereby conveniently generating a body-fitting mesh of the underlying surface of the target area, which can effectively improve the generation efficiency of the body-fitting mesh of the underlying surface.

[0004] According to one aspect of an embodiment of the present invention, a method for generating a body-fitting mesh of an underlying surface for high-precision simulation is provided, the method comprising:

[0005] Acquire target building data of a target area, wherein the target building data includes building indication data of each building in the target area;

[0006] Determine building vertex indication data of each building based on the building indication data of each building, wherein the building vertex indication data of one building includes vertex data of each building vertex in the corresponding building, and one vertex data includes vertex coordinates of the vertex of the corresponding building;

[0007] Generating initial top surface indication data and side surface indication data of each building based on the building vertex indication data of each building respectively, and determining target top surface indication data of each building based on the initial top surface indication data of each building respectively;

[0008] Based on the target top surface indication data and side surface indication data of each building, generating a three-dimensional model of the underlying surface of the target area;

[0009] Based on the underlying surface three-dimensional model, an underlying surface body-fitting mesh of the target area is generated, and the underlying surface body-fitting mesh supports diffusion simulation of the target area.

[0010] According to another aspect of an embodiment of the present invention, there is provided a device for generating a body-fitting mesh of an underlying surface for high-precision simulation, the device comprising:

[0011] An acquisition unit, configured to acquire target building data of a target area, wherein the target building data includes building indication data of each building in the target area;

[0012] A processing unit, configured to determine building vertex indication data of each building based on the building indication data of each building, wherein the building vertex indication data of one building includes vertex data of each building vertex in the corresponding building, and one vertex data includes vertex coordinates of the vertex of the corresponding building;

[0013] The processing unit is further used to generate initial top surface indication data and side surface indication data of each building based on the building vertex indication data of each building, and determine target top surface indication data of each building based on the initial top surface indication data of each building;

[0014] The processing unit is further used to generate a three-dimensional model of the underlying surface of the target area based on the target top surface indication data and the side surface indication data of each building;

[0015] The processing unit is further used to generate an underlying surface body-fitting mesh of the target area based on the underlying surface three-dimensional model, and the underlying surface body-fitting mesh supports diffusion simulation of the target area.

[0016] According to another aspect of an embodiment of the present invention, an electronic device is provided, comprising a processor and a memory storing a program, wherein the program comprises instructions, which, when executed by the processor, enable the processor to perform the above-mentioned method.

[0017] According to another aspect of an embodiment of the present invention, a non-transitory computer-readable storage medium storing computer instructions is provided, wherein the computer instructions are used to enable a computer to execute the above-mentioned method.

[0018] The embodiment of the present invention can obtain the target building data of the target area, the target building data includes the building indication data of each building in the target area; and based on the building indication data of each building, the building vertex indication data of each building is determined, the building vertex indication data of one building includes the vertex data of each building vertex in the corresponding building, and one vertex data includes the vertex coordinates of the vertex of the corresponding building. Based on this, the initial top surface indication data and side surface indication data of each building can be generated based on the building vertex indication data of each building, and the target top surface indication data of each building can be determined based on the initial top surface indication data of each building. Further, the underlying surface three-dimensional model of the target area can be generated based on the target top surface indication data and side surface indication data of each building; and based on the underlying surface three-dimensional model, the underlying surface body-fitting mesh of the target area is generated, and the underlying surface body-fitting mesh supports the use of diffusion simulation for the target area. It can be seen that the embodiment of the present invention can conveniently generate the underlying surface three-dimensional model of the target area through the target top surface indication data and the side surface indication data of each building in the target area, thereby conveniently generating the underlying surface body-fitting mesh of the target area, which can effectively improve the generation efficiency of the underlying surface body-fitting mesh; and the target top surface indication data and the side surface indication data of a building can be used to represent the three-dimensional building model of the corresponding building, that is, the embodiment of the present invention can generate the three-dimensional building model of any building through the target top surface indication data and the side surface indication data of any building, that is, when generating the three-dimensional building model, the embodiment of the present invention can only generate the side surface and the top surface, without generating the bottom surface of the building below the ground that needs to be eliminated later when generating the underlying surface body-fitting mesh, which can effectively save computing resources; in addition, the embodiment of the present invention can accurately represent the top surface of the building through the target top surface indication data of each building, which can effectively improve the accuracy of the target top surface indication data, and then improve the quality of the underlying surface three-dimensional model, so as to realize high-precision simulation (i.e. diffusion simulation) through the high-quality underlying surface three-dimensional model. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Further details, features and advantages of the invention are disclosed in the following description of exemplary embodiments in conjunction with the accompanying drawings, in which:

[0020] Figure 1 A schematic flow chart of a method for generating a body-fitting mesh of an underlying surface for high-precision simulation according to an exemplary embodiment of the present invention is shown;

[0021] Figure 2 A schematic flow chart of another underlying surface body-fitting mesh generation method for high-precision simulation according to an exemplary embodiment of the present invention is shown;

[0022] Figure 3 A schematic flow chart of another underlying surface body-fitting mesh generation method for high-precision simulation according to an exemplary embodiment of the present invention is shown;

[0023] Figure 4 A schematic flow chart of another underlying surface body-fitting grid generation method for high-precision simulation according to an exemplary embodiment of the present invention is shown;

[0024] Figure 5 A schematic diagram of a three-dimensional model of an underlying surface according to an exemplary embodiment of the present invention is shown;

[0025] Figure 6 A schematic diagram of an underlying surface body-fitting grid according to an exemplary embodiment of the present invention is shown;

[0026] Figure 7 A schematic diagram of another underlying surface body-fitting grid according to an exemplary embodiment of the present invention is shown;

[0027] Figure 8 A schematic block diagram of a device for generating a body-fitting mesh of an underlying surface for high-precision simulation according to an exemplary embodiment of the present invention is shown;

[0028] Fig. 9 A block diagram of an exemplary electronic device that can be used to implement an embodiment of the present invention is shown. DETAILED DESCRIPTION

[0029] Embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although certain embodiments of the present invention are shown in the accompanying drawings, it should be understood that the present invention can be implemented in various forms and should not be construed as being limited to the embodiments described herein, which are instead provided for a more thorough and complete understanding of the present invention. It should be understood that the drawings and embodiments of the present invention are only for exemplary purposes and are not intended to limit the scope of protection of the present invention.

[0030] It should be understood that the various steps described in the method embodiments of the present invention may be performed in different orders and / or in parallel. In addition, the method embodiments may include additional steps and / or omit the steps shown. The scope of the present invention is not limited in this respect.

[0031] The term "including" and its variations used in this document are open inclusions, that is, "including but not limited to". The term "based on" means "based at least in part on". The term "one embodiment" means "at least one embodiment"; the term "another embodiment" means "at least one other embodiment"; the term "some embodiments" means "at least some embodiments". Relevant definitions of other terms will be given in the following description. It should be noted that the concepts of "first", "second", etc. mentioned in the present invention are only used to distinguish different devices, modules or units, and are not used to limit the order or interdependence of the functions performed by these devices, modules or units.

[0032] It should be noted that the modifications of "one" and "plurality" mentioned in the present invention are illustrative rather than restrictive, and those skilled in the art should understand that, unless otherwise clearly indicated in the context, it should be understood as "one or more".

[0033] The names of the messages or information exchanged between multiple devices in the embodiments of the present invention are only used for illustrative purposes, and are not used to limit the scope of these messages or information.

[0034] It should be noted that the execution subject of the underlying surface body-fitting mesh generation method for high-precision simulation provided by the embodiment of the present invention can be one or more electronic devices, and the present invention does not limit this; wherein, the electronic device can be a terminal (i.e., a client) or a server, then when the execution subject includes multiple electronic devices, and the multiple electronic devices include at least one terminal and at least one server, the underlying surface body-fitting mesh generation method for high-precision simulation provided by the embodiment of the present invention can be jointly executed by the terminal and the server. Accordingly, the terminal mentioned here can include but is not limited to: smart phones, tablet computers, laptops, desktop computers, etc.; the server mentioned here can be an independent physical server, or a server cluster or distributed system composed of multiple physical servers, or a cloud server that provides cloud services, cloud databases, cloud computing (cloud computing), cloud functions, cloud storage, network services, cloud communications, middleware services, domain name services, security services, CDN (Content Delivery Network), and basic cloud computing services such as big data and artificial intelligence platforms, etc.

[0035] Based on the above description, an embodiment of the present invention proposes a method for generating a body-fitting mesh of an underlying surface for high-precision simulation. The method for generating a body-fitting mesh of an underlying surface for high-precision simulation can be executed by the electronic device (terminal or server) mentioned above; or, the method for generating a body-fitting mesh of an underlying surface for high-precision simulation can be executed jointly by a terminal and a server. For the sake of convenience, the following description will be given by taking the electronic device executing the method for generating a body-fitting mesh of an underlying surface for high-precision simulation as an example; Figure 1 As shown, the underlying surface body-fitting grid generation method for high-precision simulation may include the following steps S101-S105:

[0036] S101, acquiring target building data of a target area, where the target building data includes building indication data of each building in the target area.

[0037] Optionally, the target area may be any area, which is not limited in the embodiment of the present invention. Optionally, a building may include multiple building contour points; Optionally, the building indication data of a building may include but is not limited to: the contour point coordinates of each building contour point in the corresponding building and the building height indication information of the corresponding building, which is not limited in the embodiment of the present invention.

[0038] In the embodiment of the present invention, the target building data may be obtained in the following ways, but not limited to:

[0039] The first acquisition method: the target building data of the target area may be stored in the storage space of the electronic device itself. In this case, the electronic device may acquire the target building data from its own storage space.

[0040] The second acquisition method: the electronic device can obtain a building data download link of the target area, and use the building data downloaded based on the building data download link as the target building data.

[0041] The third acquisition method: electronic devices can obtain initial building data. The initial building data can be an original SHP (ESRI shapefile) data (i.e., SHP file, an open spatial data format). SHP data stores a layer of geometric graphics, such as lines, points, or polygons, and is associated with a geographic coordinate system. It is a composite data set and can be composed of at least three files: .shp, .shx (an index file used to store the affiliation between map elements) and .dbf (a database format file). SHP files are widely used in various maps and map features. Common SHP files containing building information may include building id (Identity document), coordinates of each boundary point on the bottom surface of the building (2D, two-dimensional, i.e., the initial contour point coordinates of the building contour points), number of building floors, etc. Based on this, the electronic device can clip the initial building data according to the target area range of the target area to obtain clipped building data, and the clipped building data may include initial building indication data of each building in the target area, and the initial building indication data of a building may include initial contour point coordinates and the number of building floors of each building contour point in the corresponding building, and an initial contour point coordinate may be a two-dimensional longitude and latitude coordinate; and the clipped building data may be used to determine the target building data. Optionally, a building contour point of a building can be used to indicate multiple bottom surface vertices in the bottom surface of the corresponding building and multiple top surface vertices in the top surface of the corresponding building, and a building contour point may correspond to a bottom surface vertex and a top surface vertex, and the initial building data may include initial building indication data of each initial building in at least one initial building.

[0042] Optionally, when the initial building data is clipped according to the target area range of the target area to obtain the clipped building data, each initial building in at least one initial building can be traversed, and the currently traversed initial building can be used as the current initial building, and the geometric information of the current initial building (that is, the initial contour point coordinates of each building contour point in the current initial building) can be determined from the initial building indication data of the current initial building; and according to the target area range of the target area (that is, the longitude and latitude range of the target area), it can be judged whether the initial contour point coordinates of each building contour point in the current initial building are all within the longitude and latitude range of the target area (that is, none of them exceed the longitude and latitude range of the target area); if the initial contour point coordinates of each building contour point in the current initial building are all within the longitude and latitude range of the target area, then the initial building indication data of the current initial building is added to the clipped building data (to take the current initial building as a building in the target area), so as to obtain the clipped building data (which can be a new SHP file) after traversing each initial building in at least one initial building. Optionally, the electronic device may also create a new empty index linked list to store the indexes of the buildings in the target area. In this case, if the initial contour point coordinates of each building contour point in the current initial building are within the longitude and latitude range of the target area, the index of the current initial building (such as id) is added to the above-mentioned index linked list, and after the traversal is completed, the initial building indication information of the initial buildings corresponding to each index in the index linked list is output and added to the cropped building data.

[0043] Optionally, when the cropped building data is used to determine the target building data, for any building in the target area, the initial building indication data of any building can be determined from the cropped building data, and the initial contour point coordinates of each building contour point in any building can be converted to obtain the contour point coordinates of each building contour point in any building. A contour point coordinate can be the coordinate of the corresponding building contour point in a Cartesian coordinate system (such as a unit of meters, etc.), and a contour point coordinate can be a two-dimensional coordinate in a Cartesian coordinate system with the target point as the origin; optionally, the target point can be the center point of the target area, or it can be The upper left corner point of the target area, etc., are not limited in the embodiment of the present invention; based on this, the coordinates of each building contour point in any building can be converted from the initial contour point coordinates (i.e., longitude and latitude coordinates) to contour point coordinates (i.e., Cartesian coordinates with the target point as the origin), that is, the initial contour point coordinates of any building contour point can be used to calculate the x coordinate (i.e., horizontal coordinate) and y coordinate (i.e., vertical coordinate) of any building contour point in the Cartesian coordinate system with the target point as the origin, so as to obtain the contour point coordinates of any building contour point, thereby adding the contour point coordinates of each building contour point in any building to the building indication data of any building. Optionally, the electronic device can also add the number of building floors of any building to the building indication data of any building, so as to use the number of building floors of any building as the building height indication information of any building; or, the height of any building (i.e., building height) can be calculated by using the number of building floors and the floor height (i.e., the height of a single floor) of any building, and the height of any building can be added to the building indication data of any building, so as to use the height of any building as the building height indication information of any building, so as to achieve the acquisition of target building data; and so on. Optionally, the electronic device may also assign an index to each building in the target area, and add the index of any building to the building indication data of any building, so that the building indication data of any building may also include the index of any building (such as building ID, etc.); or, the index of each building may be added to the target building data, so that the target building data may also include the index of each building. Optionally, the floor height may be set according to experience or according to actual needs, which is not limited in the embodiment of the present invention; illustratively, the floor height may be 3m (meter).

[0044] S102, determining building vertex indication data of each building based on the building indication data of each building, wherein the building vertex indication data of one building includes vertex data of each building vertex in the corresponding building, and one vertex data includes vertex coordinates of the vertex of the corresponding building.

[0045] Among them, a building may include multiple building vertices, and the multiple building vertices in a building may include multiple bottom surface vertices of the corresponding building (i.e., multiple bottom surface vertices in the bottom surface of the corresponding building) and multiple top surface vertices (i.e., multiple top surface vertices in the top surface of the corresponding building); then correspondingly, each building vertex in a building may be each building vertex among the multiple building vertices included in the corresponding building. In the embodiment of the present invention, a point in a building (such as a building vertex or a bottom surface vertex, etc.) may also be referred to as a point of the corresponding building; correspondingly, a point in a surface may also be referred to as a point of the corresponding surface, and so on.

[0046] Optionally, a vertex data may also include an index of a corresponding building vertex, that is, the vertex data of a building vertex may include but is not limited to the vertex coordinates and index of the corresponding building vertex, etc., which is not limited in the embodiment of the present invention; wherein, a vertex coordinate may be a three-dimensional coordinate (including an x-coordinate, a y-coordinate and a z-coordinate (i.e., a vertical coordinate, the vertical coordinate of a building vertex may be the height of the corresponding building vertex)); illustratively, the z-coordinate of a bottom vertex of any building may be 0 (i.e., the height of any bottom vertex may be 0), and the z-coordinate of a top vertex of any building may be determined based on the height of any building (i.e., the height of a top vertex in any building may be determined based on the height of any building). Optionally, a building contour point may correspond to a bottom vertex and a top vertex, that is, the contour point coordinates of a building contour point may include an x-coordinate and a y-coordinate, then the x-coordinates in the vertex coordinates of the bottom vertex and the top vertex corresponding to a building contour point may both be the x-coordinates of the corresponding building contour point, and the y-coordinates in the vertex coordinates of the bottom vertex and the top vertex corresponding to a building contour point may both be the y-coordinates of the corresponding building contour point. For example, the coordinates of a vertex may be expressed as vx coordinate y coordinate z coordinate, that is, as “v{x}{y}{z}”, where v may represent a point.

[0047] S103, generating initial top surface indication data and side surface indication data of each building based on the building vertex indication data of each building, and determining target top surface indication data of each building based on the initial top surface indication data of each building.

[0048] The target top surface indication data and side surface indication data of a building can be used to represent the three-dimensional building model of the corresponding building. Correspondingly, the target top surface indication data and side surface indication data of all buildings in the target area can be used to represent the three-dimensional building complex model, that is, the target top surface indication data and side surface indication data of each building in the target area can be used to represent the three-dimensional building complex model of the target area.

[0049] In the embodiment of the present invention, it can be assumed that the shapes of all buildings are basically the same from top to bottom. Optionally, for any building in the target area, the electronic device can generate the side indication data of any building based on the building vertex indication data of any building in accordance with the target side link order, and the side indication data of any building includes the surface representation information of each side of the k sides of any building, and one surface representation information includes the index of each point in a surface (that is, the corresponding surface can be represented by the index of each point in a surface), k is the number of building contour points in any building, and k is an integer greater than 1; optionally, the target side link order can be clockwise (i.e., clockwise order), or counterclockwise (i.e., counterclockwise order), etc., and the embodiment of the present invention does not limit this.

[0050] Optionally, the indices of each bottom surface vertex in any building may be p+1, p+2, ..., p+k, and the indices of each top surface vertex in any building may be p+k+1, p+k+2, ..., p+k+k; where p is the initial vertex index of any building, and the number of bottom surface vertices and the number of top surface vertices in any building are both k. Based on this, since the side faces are all rectangles (convex polygons), the k side faces of any building can be directly generated according to the target side face linking order; illustratively, assuming that the target side face linking order is counterclockwise, each side face can be linked counterclockwise, then the face representation information of the i-th side face (i∈[1, k-1]) of any building can be f p+i p+i+1p+i+1+kp+i+k, and the face representation information of the k-th side face can be f p+k p+1p+k+1p+k+k; wherein, f can represent a face, when m in p+m is less than or equal to k, p+m can represent the index of the m-th bottom surface vertex among the multiple bottom surface vertices of any building (such as p+i or p+1 mentioned above), and when m is greater than k, p+m can represent the index of the mk-th top surface vertex among the multiple top surface vertices of any building (such as p+i+k mentioned above), and m is a positive integer.

[0051] Correspondingly, the electronic device can determine the vertex data of each top surface vertex in the top surface of any building from the building vertex indication data of any building; and based on the vertex data of each top surface vertex, triangulate the top surface of any building to obtain the initial top surface indication data of any building, and the initial top surface indication data of any building includes the surface representation information of each initial top surface triangulation surface among multiple initial top surface triangulation surfaces of the top surface of any building.

[0052] Optionally, the electronic device may perform Delaunay triangulation (a triangulation algorithm) on the top surface of any building to obtain surface representation information of each initial top surface triangulation surface (also referred to as triangular surface for short) that does not overlap with each other and can cover the top surface of any building (one surface representation information is represented by the index of each point in the corresponding surface, and the surface representation information of a surface may also be called the point index of the corresponding surface). Optionally, the electronic device may call a module for implementing Delaunay triangulation in the scipy library (a commonly used software package in the fields of mathematics, science, and engineering) in Python (a high-level scripting language that combines interpretability, compilation, interactivity, and object-orientedness), and perform Delaunay triangulation on the top surface of any building based on vertex data of each top surface vertex; wherein the point index output by calling the Delaunay triangulation module in Python starts from 0, and the index needs to be corrected. For example, if the index information of an initial top surface triangulation surface of the top surface of any building output is 0 1 2, the index actually written into the surface representation information of the initial top surface triangulation surface should be added with p+k+1 (that is, the surface representation information of the initial top surface triangulation surface can be: f p+k+1p+k+2p+k+3, that is, index 0 can correspond to the index "p+k+1" in the index of each top surface vertex in any building, index 1 can correspond to the index "p+k+2" in the index of each top surface vertex in any building, and so on), so that the initial top surface indication data of any building can be obtained.

[0053] It should be noted that redundant triangles may be generated when triangulating a non-convex polygon, that is, redundant initial top triangulation surfaces may be generated. Accordingly, when determining the target top surface indication data of each building based on the initial top surface indication data of each building respectively, for any building in the target area, the electronic device can traverse each initial top surface triangulation surface of multiple initial top surface triangulation surfaces of the top surface of any building, and use the currently traversed initial top surface triangulation surface as the current initial top surface triangulation surface; then, the center of gravity of the current initial top surface triangulation surface can be determined based on the surface representation information of the current initial top surface triangulation surface, that is, the vertex coordinates of each top surface vertex in the current initial top surface triangulation surface can be determined based on the surface representation information of the current initial top surface triangulation surface, thereby performing a mean operation on the vertex coordinates of each top surface vertex in the current initial top surface triangulation surface, so as to use the average value between the vertex coordinates of each top surface vertex in the current initial top surface triangulation surface as the center of gravity of the current initial top surface triangulation surface; if the center of gravity of the current initial top surface triangulation surface is located at any building if the current initial top surface triangulation surface is located within the top surface of any building (at this time, it can be determined that the current initial top surface triangulation surface is located within the top surface of any building), the surface representation information of the current initial top surface triangulation surface is added to the target top surface indication data of any building, so that the current initial top surface triangulation surface is used as a target top surface triangulation surface of the top surface of any building; if the centroid of the current initial top surface triangulation surface is not located within the top surface of any building (at this time, it can be determined that the current initial top surface triangulation surface is not located within the top surface of any building), the surface representation information of the current initial top surface triangulation surface is not added to the target top surface indication data of any building; after traversing each of the multiple initial top surface triangulation surfaces of the top surface of any building, the target top surface indication data of any building can be obtained; wherein, the target top surface indication data of any building includes the surface representation information of each target top surface triangulation surface of the multiple target top surface triangulation surfaces of the top surface of any building. Optionally, each target top surface triangulation surface of the top surface of any building may be located within the top surface of any building. Based on this, only the initial top surface triangulation surface whose center of gravity is located within the top surface of any building can be used as the target top surface triangulation surface of the top surface of any building, which can effectively improve the accuracy of triangulation, so as to effectively improve the accuracy of the target top surface indication data, and thus improve the quality of the subsequent underlying surface three-dimensional model. Optionally, after completing the triangulation, the index of each initial top surface triangulation surface obtained can be written in the form of "f{index1}{index2}{index3}" until all the initial top surface triangulation surfaces are output; wherein, index can be expressed as an index, that is, the surface representation information of a top surface triangulation surface can include the index of each of the three top surface vertices.It can be seen that the embodiment of the present invention proposes to use the triangle centroid method to determine whether the triangle generated by triangulation is outside the top surface, so when the top surface is a concave polygon, the effect of triangulating the concave polygon can be improved.

[0054] Optionally, the electronic device may also determine whether the number of building contour points in any building is greater than a preset contour point threshold; if the number of building contour points in any building is greater than the preset contour point threshold, the above-mentioned vertex data based on each top surface vertex is triggered to triangulate the top surface of any building to obtain initial top surface indication data of any building, and then the above-mentioned traversal of each initial top surface triangulation surface of the top surface of any building may be triggered to determine the target top surface indication data of any building; if the number of building contour points in any building is less than or equal to the preset contour point threshold, the vertex data of each top surface vertex in the top surface of any building is used to generate the top surface representation information of any building (at this time, the top surface representation information of any building may include the index of each top surface vertex in the top surface of any building, such as the top surface representation information may be represented as f p+k+1p+k+2…p+k+k), so as to add the top surface representation information of any building to the initial top surface indication data of any building, and the top surface representation information of any building includes the index of each top surface vertex in the top surface of any building; based on this, when determining the target top surface indication data of each building based on the initial top surface indication data of each building, the initial top surface indication data of any building can be used as the target top surface indication data of any building. Optionally, the preset contour point number threshold can be set according to experience or according to actual needs, and the embodiment of the present invention does not limit this; illustratively, the preset contour point number threshold can be 4, and it should be understood that when the number of building contour points in any building does not exceed 4 (that is, less than or equal to 4), the top surface of any building is usually a simple polygon, so the index of each top surface vertex in any building can be directly output according to the target top surface order; optionally, the target top surface order can be clockwise or counterclockwise, etc., and the embodiment of the present invention does not limit this. Based on this, the embodiment of the present invention can first determine whether the building outline is a complex polygon (that is, determine whether the number of building outline points is greater than the preset outline point threshold, and the complex polygon can be the top surface whose number of building outline points is greater than the preset outline point threshold), so as to only triangulate the complex polygon, which can effectively improve the computing efficiency.

[0055] S104, generating a three-dimensional model of the underlying surface of the target area based on the target top surface indication data and the side surface indication data of each building.

[0056] The target top surface indication data and side surface indication data of each building can constitute a three-dimensional building complex model of the target area; optionally, the three-dimensional building complex model can be an obj file (that is, it can be stored in the form of an obj file, and the obj file storing the three-dimensional building complex model can be called a three-dimensional building complex model obj file, that is, the three-dimensional building complex model can be called a three-dimensional building complex model obj file), that is, after obtaining the target top surface indication data and side surface indication data of any building, the target top surface indication data and side surface indication data of any building can also be added to the three-dimensional building complex model obj file to generate a three-dimensional building complex model in obj format, that is, a three-dimensional building complex model obj file containing the target top surface indication data and side surface indication data of each building can be generated. An obj format file can include but is not limited to at least one of the following: vertex data, free-form surface / surface attributes, drawing index sequence, free-form surface / surface content declaration, associated free-form surface, group and rendering attribute information. Most common drawing indexes are expressed as geometric vertices, texture coordinates, vertex normals, and polygon faces. Compared with similar file formats such as stl files, the obj format supports high-resolution data, and the obj file can represent complex or irregularly shaped objects by dividing its surface into small triangle blocks. This subdivision and assembly process makes it easier to operate and render the design.

[0057] In one embodiment, the electronic device may use the target top surface indication data and side surface indication data of each building to generate a three-dimensional building complex model of the target area, and use the three-dimensional building complex model as the underlying surface three-dimensional model of the target area. At this time, the underlying surface three-dimensional model may only include the three-dimensional building complex model. Optionally, the underlying surface three-dimensional model can be an obj file (that is, it can be stored in the form of an obj file, and the obj file of the underlying surface three-dimensional model can be called the underlying surface three-dimensional model obj file); in this case, the three-dimensional building complex model can be used as the underlying surface three-dimensional model, that is, the three-dimensional building complex model obj file can be used as the underlying surface three-dimensional model obj file. Based on this, the embodiment of the present invention can generate an underlying surface three-dimensional model in obj format. Based on this, the bottom surface indicated by the underlying surface three-dimensional model of the target area can be a plane with z equal to 0.

[0058] In another embodiment, the electronic device may also generate a three-dimensional terrain model of the target area, so as to use the target top surface indication data and side surface indication data of each building, and the three-dimensional terrain model, to generate a three-dimensional model of the underlying surface of the target area, etc. The specific implementation of generating the three-dimensional terrain model of the target area and using the target top surface indication data and side surface indication data of each building, and the three-dimensional terrain model, to generate the three-dimensional model of the underlying surface of the target area can be seen as follows, and the embodiments of the present invention will not be repeated here.

[0059] S105, generating an underlying surface body-fitting mesh of the target area based on the underlying surface three-dimensional model, wherein the underlying surface body-fitting mesh supports diffusion simulation of the target area.

[0060] In the embodiment of the present invention, the electronic device can use the underlying surface body-fitting grid to perform diffusion simulation on any substance (such as any pollutant) in the target area, that is, the underlying surface body-fitting grid can support the diffusion simulation of any substance in the target area. Optionally, any substance can be any aerosol or any pollutant, etc., which is not limited in the embodiment of the present invention.

[0061] The embodiment of the present invention can obtain the target building data of the target area, the target building data includes the building indication data of each building in the target area; and based on the building indication data of each building, the building vertex indication data of each building is determined, the building vertex indication data of one building includes the vertex data of each building vertex in the corresponding building, and one vertex data includes the vertex coordinates of the vertex of the corresponding building. Based on this, the initial top surface indication data and side surface indication data of each building can be generated based on the building vertex indication data of each building, and the target top surface indication data of each building can be determined based on the initial top surface indication data of each building. Further, the underlying surface three-dimensional model of the target area can be generated based on the target top surface indication data and side surface indication data of each building; and based on the underlying surface three-dimensional model, the underlying surface body-fitting mesh of the target area is generated, and the underlying surface body-fitting mesh supports the use of diffusion simulation for the target area. It can be seen that the embodiment of the present invention can conveniently generate the underlying surface three-dimensional model of the target area through the target top surface indication data and the side surface indication data of each building in the target area, thereby conveniently generating the underlying surface body-fitting mesh of the target area, which can effectively improve the generation efficiency of the underlying surface body-fitting mesh; and the target top surface indication data and the side surface indication data of a building can be used to represent the three-dimensional building model of the corresponding building, that is, the embodiment of the present invention can generate the three-dimensional building model of any building through the target top surface indication data and the side surface indication data of any building, that is, when generating the three-dimensional building model, the embodiment of the present invention can only generate the side surface and the top surface, without generating the bottom surface of the building below the ground that needs to be eliminated later when generating the underlying surface body-fitting mesh, which can effectively save computing resources; in addition, the embodiment of the present invention can accurately represent the top surface of the building through the target top surface indication data of each building, which can effectively improve the accuracy of the target top surface indication data, and then improve the quality of the underlying surface three-dimensional model, so as to realize high-precision simulation (i.e. diffusion simulation) through the high-quality underlying surface three-dimensional model.

[0062] Based on the above description, an embodiment of the present invention further proposes a more specific underlying surface body-fitting mesh generation method for high-precision simulation. Accordingly, the underlying surface body-fitting mesh generation method for high-precision simulation can be executed by the electronic device (terminal or server) mentioned above; or, the underlying surface body-fitting mesh generation method for high-precision simulation can be executed by the terminal and the server together. For the sake of ease of explanation, the following description will be taken as an example of an electronic device executing the underlying surface body-fitting mesh generation method for high-precision simulation; please refer to Figure 2 The underlying surface body-fitting grid generation method for high-precision simulation may include the following steps S201-S207:

[0063] S201, obtaining initial terrain data of a target area, where the initial terrain data includes an initial terrain height of each grid point in the target area.

[0064] Optionally, the target area may include multiple grid areas, and each grid area in the target area may be each grid area in the multiple grid areas. Optionally, the multiple grid areas in the target area may be divided according to the target resolution, and the target resolution may be used to indicate the size of a grid area in the target area; optionally, the target resolution may be set according to experience or according to actual needs, which is not limited in the embodiments of the present invention. Among them, a grid point in the target area may be the center point of a grid area in the target area, that is, each grid point in the target area may be the center point of each grid area in the target area. Optionally, the initial terrain height of a grid point may be the altitude of the corresponding grid point.

[0065] Optionally, the initial terrain data may include the initial grid point coordinates of each grid point in the target area, and the initial grid point coordinates of a grid point may include but are not limited to the x-coordinate, y-coordinate and initial terrain height of the corresponding grid point (here, the z-coordinate of the corresponding grid point); that is, the initial terrain data may also include the x-coordinate and y-coordinate of each grid point in the target area. Optionally, an initial grid point coordinate and the following one of the grid point coordinates may be three-dimensional coordinates in a Cartesian coordinate system with the target point as the origin. Optionally, the initial terrain data of the target area may be a point cloud data, that is, the embodiment of the present invention may obtain the point cloud data of the target area, which may include the initial grid coordinates of each grid point.

[0066] In the embodiment of the present invention, the initial terrain data may be obtained in the following ways, but not limited to:

[0067] The first acquisition method: the initial terrain data of the target area may be stored in the storage space of the electronic device itself. In this case, the electronic device may acquire the initial terrain data of the target area from the storage space of the electronic device itself.

[0068] The second acquisition method: the electronic device can obtain a download link for the target area terrain data, and use the terrain data downloaded based on the download link for the target area terrain data as the initial terrain data for the target area.

[0069] The third acquisition method: the electronic device can obtain the original terrain data, and clip the original terrain data according to the target area range of the target area to obtain the clipped terrain data, the clipped terrain data may include the original grid point data of each original grid point in the target area, the original grid point data of an original grid point may include the latitude and longitude coordinates and the original terrain height of the corresponding original grid point, and an original terrain height may be the altitude of the corresponding original grid point; based on this, the initial terrain data can be determined based on the clipped terrain data to achieve the acquisition of the initial terrain data of the target area, etc. Optionally, the original terrain data can be a DEM (Digital elevation model, digital terrain model, also known as digital elevation model) data (the original terrain data can also be called original DEM data or original DEM file), which can usually be in tif format (an image file format), and the digital elevation model can be a representation of the topological surface of the earth's bare surface (bare ground), excluding trees, buildings and any other surface objects.

[0070] Optionally, when the original terrain data is clipped according to the target area range of the target area to obtain the clipped terrain data, the original grid point data of all original grid points whose latitude and longitude coordinates are within the target area range can be added to the clipped terrain data to obtain the original grid point data of each original grid point in the target area, thereby obtaining the clipped terrain data.

[0071] Optionally, when determining the initial terrain data based on the clipped terrain data, the target area can be gridded according to the target resolution (at this time, the target resolution can be used to indicate the area size of a grid area in the latitude and longitude coordinate system) and the target area range to obtain multiple grid areas in the target area (that is, the latitude and longitude coordinates of each grid point in the target area can be obtained, and a grid point can be the center point of a grid area), so that the original grid point data of each original grid point in the target area can be used to calculate the initial terrain height of each grid point respectively, and the longitude and latitude coordinates of each grid point can be transformed to obtain the xy coordinates of each grid point (that is, the xy coordinates of each grid point in the Cartesian coordinate system with the target point as the origin are obtained), so as to obtain the initial terrain data; optionally, for any grid point in the target area, the first P original grid points closest to the longitude and latitude coordinates of any grid point can be determined from the target area, so as to perform a weighted summation (such as a mean operation, etc.) of the original terrain heights of each original grid point in the first P original grid points to obtain the initial terrain height of any grid point. Alternatively, the electronic device may also first perform coordinate conversion on the target area range and the longitude and latitude coordinates of each original grid point to obtain the target conversion range of the target area in the Cartesian coordinate system and the conversion coordinates of each original grid point (i.e., the xy coordinates with the target point as the coordinate origin), and may grid-divide the target area according to the target resolution (at this time, the target resolution may be used to indicate the area size of a grid area in the Cartesian coordinate system) and the target conversion range to obtain multiple grid areas in the target area (i.e., the xy coordinates of each grid point in the target area), based on which, for any grid point in the target area, the first P original grid points closest to the xy coordinate of any grid point may be determined from the target area based on the xy coordinates of any grid point and the conversion coordinates of each original grid point in the target area, so as to perform weighted summation on the original terrain heights of each original grid point in the first P original grid points to obtain the initial terrain height of any grid point, thereby obtaining the initial grid point coordinates of any grid point, and so on. Wherein, P may be a positive integer.

[0072] S202, determining the relative terrain height of each grid point based on the initial terrain height of each grid point; and generating a three-dimensional terrain model of the target area based on the relative terrain height of each grid point.

[0073] Optionally, when determining the relative terrain height of each grid point based on the initial terrain height of each grid point, the electronic device may determine the minimum initial terrain height from the initial terrain height of each grid point, and use the difference between the initial terrain height of each grid point and the minimum initial terrain height as the relative terrain height of the corresponding grid point, that is, the relative terrain height of any grid point may be the difference between the initial terrain height of any grid point and the minimum initial terrain height, that is, the altitude of the lowest point may be subtracted to achieve the determination of the relative terrain height of each grid point. It should be understood that the three-dimensional terrain model does not need to reflect the actual altitude of the terrain, but only needs to reflect the terrain undulations of the target area. Considering that when the altitude is too high, unnecessary storage and computing resources are consumed in the subsequent background grid generation and grid refinement steps, the embodiment of the present invention may convert the altitude into a relative terrain height relative to the lowest point of the target area (the relative terrain height of this point may be 0).

[0074] Optionally, when generating a three-dimensional terrain model of the target area based on the relative terrain height of each grid point, the electronic device may triangulate the target area based on the relative terrain height of each grid point to obtain a terrain triangulation result of the target area, the terrain triangulation result includes the grid point coordinates of each grid point and the surface representation information of each terrain triangulation surface in multiple terrain triangulation surfaces, the grid point coordinates of a grid point may include the x coordinate, y coordinate and relative terrain height of the corresponding grid point (that is, the z coordinate of a grid point may be the relative terrain height of the corresponding grid point at this time); and the terrain triangulation result is added to the three-dimensional terrain model file to realize the generation of the three-dimensional terrain model of the target area. In other words, the target area may be triangulated based on the grid point coordinates of each grid point to obtain a terrain triangulation result of the target area; optionally, the grid point coordinates of each grid point may also be called the relative terrain data of the target area, that is, the relative terrain data may include the grid point coordinates of each grid point, and the target area may be triangulated based on the relative terrain data of the target area. Based on this, when the initial terrain data is point cloud data, an embodiment of the present invention proposes a method for generating a three-dimensional bottom surface based on the point cloud data and through triangulation. That is, the embodiment of the present invention can triangulate the point cloud data of relative terrain height to generate a three-dimensional terrain model; and, when processing the initial terrain height (altitude), it is converted into relative terrain height, which can effectively avoid the waste of computing and storage resources caused by the subsequent generation of overly tall background grids. Among them, the three-dimensional terrain model file can be used to represent the three-dimensional terrain model of the target area; optionally, the three-dimensional terrain model file can be an obj file, that is, the format of the three-dimensional terrain model can be in obj format, that is, the embodiment of the present invention can generate a three-dimensional terrain model in obj format; optionally, the three-dimensional terrain model file can also be called a three-dimensional terrain model obj file, so that the terrain triangulation result is added to the three-dimensional terrain model obj file, and the grid point coordinates of each grid point and the surface representation information of each terrain triangulation surface can be written into the three-dimensional terrain model obj file respectively, such as Figure 3 It should be understood that the three-dimensional terrain model is a continuous three-dimensional bottom surface, which can be composed of a plurality of non-overlapping triangular surfaces.

[0075] Optionally, the electronic device can perform Delaunay triangulation on the target area. Optionally, the electronic device can call the module for implementing Delaunay triangulation in the scipy library in Python (which can be referred to as the Delaunay triangulation module) to perform Delaunay triangulation on the target area; based on this, when outputting the three-dimensional terrain model obj file, the grid point coordinates of all grid points in the target area can be first written in the form of "v{x}{y}{z}" (the value of z in a grid point coordinate is the relative terrain height of the corresponding grid point), and then according to the triangulation, the surface representation information of all terrain triangulation surfaces can be output in the form of "f{index1}{index2}{index3}". It should be noted that the point index (i.e., surface representation information) output by calling the delaunay triangulation module in Python starts from 0, and the index needs to be corrected. For example, if the surface information of the first terrain triangulation surface output is 0 1 2, the index actually written into the three-dimensional terrain model file should be added by +1 (i.e., the surface representation information of the first terrain triangulation surface can be f 1 2 3). In addition, the electronic device can also record the number of all grid points written, which can be recorded as N, that is, the number of grid points in the target area can be N, and N is a positive integer.

[0076] S203, acquiring target building data of the target area, where the target building data includes building indication data of each building in the target area.

[0077] S204, determining building vertex indication data of each building based on the building indication data of each building, wherein the building vertex indication data of one building includes vertex data of each building vertex in the corresponding building, and one vertex data includes vertex coordinates of the vertex of the corresponding building.

[0078] The building indication data of a building include the contour point coordinates of each building contour point in the corresponding building and the building height indication information of the corresponding building, and a vertex data may also include the index of the vertex of the corresponding building.

[0079] Based on this, the electronic device can traverse each building in the target area and use the currently traversed building as the current building; optionally, the target building data can also include the building identification of each building in the target area, then each building identification in the target building data can be traversed, and the building indicated by the currently traversed building identification can be used as the currently traversed building to achieve traversal of each building in the target area; a building identification can be used to indicate a building, and a building identification can be the number (i.e., id) of the corresponding building. For example, the building identification of the first building in the target area can be 1, then when s represents the currently traversed building identification and the currently traversed building is the first building, the value of s can be 1. In other words, the current building can refer to the sth building.

[0080] Furthermore, the electronic device may determine the initial vertex index of the current building, and based on the initial vertex index of the current building, determine the index of each building vertex in the current building; wherein, when the current building is the first building (i.e., s=1), the initial vertex index of the current building may be p=N, and when the current building is not the first building, the initial vertex index of the current building may be p=p (here p is the initial vertex index of the building before the current building) + 2×k (here k is the number of building contour points of the building before the current building), that is, at this time the initial vertex index of the current building may be the initial vertex index of the building before the current building + 2×the number of building contour points of the building before the current building. Correspondingly, when determining the index of each building vertex in the current building based on the initial vertex index of the current building, p+1, p+2, ..., p+k can be used in sequence as the index of each bottom surface vertex in the multiple bottom surface vertices of the current building, that is, the index of each bottom surface vertex of the current building can be the initial vertex index + 1, initial vertex index + 2, ..., and initial vertex index + k of the current building (here k can be the number of building contour points of the current building); and p+k+1, p+k+2, ..., p+k+k can be used in sequence as the index of each top surface vertex in the multiple top surface vertices of the current building, that is, the index of each top surface vertex of the current building can be the initial vertex index + k+1, initial vertex index + k+2, ..., and initial vertex index + k+k of the current building, and the building vertices of a building may include multiple bottom surface vertices of the corresponding building (i.e., multiple bottom surface vertices of the bottom surface of the corresponding building) and multiple top surface vertices (i.e., multiple top surface vertices of the top surface of the corresponding building), thereby realizing the determination of the index of each building vertex in the current building.

[0081] Further, the electronic device can determine the building center point coordinates of the current building based on the contour point coordinates of each building contour point in the current building, that is, the contour point coordinates of each building contour point in the current building are averaged to obtain the building center point coordinates of the current building (a two-dimensional coordinate, that is, the x coordinate in the building center point coordinates can be the average of the x coordinates of each building contour point, and the y coordinate in the building center point coordinates can be the average of the y coordinates of each building contour point); and can determine the relative ground height of the current building based on the relative terrain height of each grid point in the M grid points corresponding to the building center point coordinates, that is, the relative terrain height of each grid point in the M grid points is weighted summed (such as average operation, etc.) to obtain the relative ground height of the current building, and the M grid points can be determined from the grid points included in the target area, and M is a positive integer. Optionally, the electronic device can determine M grid points from the target area based on the building center point coordinates and the xy coordinates of each grid point in the target grid area, and the M grid points can be the first M grid points in the target area with the closest distance between the xy coordinates and the building center point coordinates.

[0082] Then, accordingly, the electronic device can determine the vertex coordinates of each building vertex in the current building based on the contour point coordinates of each building contour point in the current building, the relative height from the ground, and the building height indication information of the current building; and can add the vertex coordinates and index of each building vertex in the current building to the building vertex indication data of the current building, so that the vertex data of a building vertex in the current building includes the vertex coordinates and index of the corresponding building vertex, thereby realizing the determination of the building vertex indication data of the current building, such as Figure 4Optionally, the x coordinate in the vertex coordinates of a building vertex may be the x coordinate of the building contour point corresponding to the corresponding building vertex, the y coordinate in the vertex coordinates of a building vertex may be the y coordinate of the building contour point corresponding to the corresponding building vertex, and the z coordinate in the vertex coordinates of a building vertex may be determined based on the building height indication information of the corresponding building and the relative height to the ground or may be zero, and a vertex coordinate may be a three-dimensional coordinate. Optionally, the electronic device may use the sum of the height of the current building and the relative height to the ground as the height of each top surface vertex in the current building (i.e., the z coordinate of the top surface vertex); optionally, when the building height indication information of a building is the number of building floors of the corresponding building, the z coordinate in the vertex coordinates of a top surface vertex in the current building (i.e., the z coordinate of a top surface vertex) may be the building height indication information of the current building × the floor height + the relative height to the ground, that is, the building height indication information of the current building and the floor height are multiplied to obtain the height of the current building, and the sum of the height of the current building and the relative height to the ground is used as the height of each top surface vertex in the current building (i.e., the z coordinate of the top surface vertex); when the building height indication information of a building is the height of the corresponding building (i.e., the building height), the z coordinate in the vertex coordinates of a top surface vertex in the current building may be the building height indication information of the current building + the relative height to the ground, that is, the sum of the building height indication information of the current building and the relative height to the ground is used as the height of each top surface vertex in the current building; accordingly, the z coordinate in the vertex coordinates of a bottom surface vertex may be zero. Among them, the x-coordinate, y-coordinate and z-coordinate in the vertex coordinates of a building vertex may also be referred to as the x-coordinate, y-coordinate and z-coordinate of the corresponding building vertex. It can be seen that the embodiment of the present invention can stretch the building height when generating the building, so as to stretch the building height to the actual building height plus the relative height of the ground where the building is located, so that the part below the ground can be eliminated when the underlying surface body-fitting mesh is generated by the subsequent docking CFD model, so that the bottom surface of the building can be ignored when processing the building part, and only the side and top surfaces of the building are generated, so as to effectively save computing resources.

[0083] Based on this, after traversing each building in the target area, the building vertex indication data of each building can be obtained. Accordingly, assuming that the number of buildings in the target area is S, when the building identification s of the current building is less than S, the buildings in the target area can be traversed continuously until each building is traversed.

[0084] S205, generating initial top surface indication data and side surface indication data of each building based on the building vertex indication data of each building, and determining target top surface indication data of each building based on the initial top surface indication data of each building.

[0085] S206, using the target top surface indication data and side surface indication data of each building and the three-dimensional terrain model, generate a three-dimensional model of the underlying surface of the target area.

[0086] In an embodiment of the present invention, the electronic device may superimpose the three-dimensional building complex model onto the three-dimensional terrain model to generate a three-dimensional model of the underlying surface. Figure 5 As shown; that is, the three-dimensional building complex model obj file containing the target top surface indication data and side surface indication data of each building can be superimposed (i.e. merged) with the three-dimensional terrain model obj file containing the three-dimensional terrain model to obtain the underlying surface three-dimensional model obj file, thereby realizing the generation of the underlying surface three-dimensional model of the target area.

[0087] In other words, the electronic device can use the three-dimensional building complex model (including the target top surface indication data and side surface indication data of each building) and the three-dimensional terrain model to generate a three-dimensional model of the underlying surface of the target area.

[0088] S207, generating an underlying surface body-fitting mesh of the target area based on the underlying surface three-dimensional model, wherein the underlying surface body-fitting mesh supports diffusion simulation of the target area.

[0089] In an embodiment of the present invention, the electronic device can import the underlying surface 3D model obj file into the CFD model to call the CFD model to generate the background mesh of the target area, that is, call the background mesh generation tool of the CFD model to generate a background mesh whose origin is consistent with the underlying surface 3D model and whose range does not exceed the underlying surface 3D model (that is, does not exceed the target area). Based on this, the underlying surface 3D model and the background mesh of the target area can be used to generate the underlying surface body-fitting mesh of the target area, such as Figure 6 As shown; that is, the mesh refinement tool of the CFD model can be called to refine the background mesh and remove the mesh below the underlying surface and inside the building, so as to generate an underlying surface body-fitting mesh that fits the real underlying surface for subsequent simulation use. The underlying surface body-fitting mesh can also be called a body-fitting mesh that fits the underlying surface tightly; optionally, the underlying surface body-fitting mesh can include all meshes in the background mesh of the target area except the meshes occupied by the underlying surface three-dimensional model, that is, it can include all meshes in the background mesh of the target area except the meshes below the underlying surface (i.e., below the ground) and inside the building.

[0090] In other embodiments, when the underlying surface three-dimensional model only includes a three-dimensional building complex model, the internal grid of the building can be removed from the background grid to generate an underlying surface body-fitting grid. In this case, the underlying surface body-fitting grid can be as follows: Figure 7As shown; optionally, at this time, features on the surface of the underlying three-dimensional model can also be extracted to remove the internal grid of the building from the background grid based on the features on the surface of the underlying three-dimensional model, thereby generating an underlying surface body-fitting grid, etc.; the present invention is not limited to this.

[0091] The embodiment of the present invention can obtain the initial terrain data of the target area, and the initial terrain data includes the initial terrain height of each grid point in the target area; thereby, based on the initial terrain height of each grid point, the relative terrain height of each grid point is determined, and based on the relative terrain height of each grid point, a three-dimensional terrain model of the target area is generated. Accordingly, the target building data of the target area can be obtained, and the target building data includes the building indication data of each building in the target area; and based on the building indication data of each building, the building vertex indication data of each building is determined, and the building vertex indication data of a building includes the vertex data of each building vertex in the corresponding building, and one vertex data includes the vertex coordinates of the vertex of the corresponding building. Then, the initial top surface indication data and side surface indication data of each building can be generated based on the building vertex indication data of each building, and the target top surface indication data of each building can be determined based on the initial top surface indication data of each building. Based on this, the target top surface indication data and side surface indication data of each building, as well as the three-dimensional terrain model, can be used to generate a three-dimensional model of the underlying surface of the target area; and based on the underlying surface three-dimensional model, the underlying surface body-fitting mesh of the target area is generated, and the underlying surface body-fitting mesh supports the use of diffusion simulation for the target area. It can be seen that the embodiment of the present invention can realize the superposition of the three-dimensional building complex model with the three-dimensional terrain model to obtain a more realistic underlying surface three-dimensional model, and then generate a more realistic underlying surface body-fitting mesh, so as to improve the accuracy of diffusion simulation through accurate underlying surface body-fitting mesh; based on this, the embodiment of the present invention proposes a method for generating a three-dimensional terrain model based on DEM data to superimpose a three-dimensional building complex model generated based on an SHP file, and then proposes a method for generating a body-fitting mesh required to support CFD simulation based on SHP data and DEM data, which has a high degree of automation, simple and efficient operation, can effectively improve the generation efficiency of the underlying surface body-fitting mesh, and can effectively improve the accuracy of the underlying surface body-fitting mesh.

[0092] Based on the description of the related embodiments of the underlying surface body-fitting mesh generation method for high-precision simulation, the embodiment of the present invention further proposes an underlying surface body-fitting mesh generation device for high-precision simulation, and the underlying surface body-fitting mesh generation device for high-precision simulation can be a computer program (including program code) running in an electronic device; Figure 8 As shown, the underlying surface body-fitting grid generation device for high-precision simulation may include an acquisition unit 801 and a processing unit 802. The underlying surface body-fitting grid generation device for high-precision simulation may be executed Figure 1 or Figure 2 The underlying surface body-fitting grid generation method for high-precision simulation, that is, the underlying surface body-fitting grid generation device for high-precision simulation can run the above-mentioned units:

[0093] An acquisition unit 801 is used to acquire target building data of a target area, wherein the target building data includes building indication data of each building in the target area;

[0094] The processing unit 802 is used to determine the building vertex indication data of each building based on the building indication data of each building, wherein the building vertex indication data of one building includes the vertex data of each building vertex in the corresponding building, and one vertex data includes the vertex coordinates of the vertex of the corresponding building;

[0095] The processing unit 802 is further configured to generate initial top surface indication data and side surface indication data of each building based on the building vertex indication data of each building, and determine target top surface indication data of each building based on the initial top surface indication data of each building;

[0096] The processing unit 802 is further configured to generate a three-dimensional model of the underlying surface of the target area based on the target top surface indication data and the side surface indication data of each building;

[0097] The processing unit 802 is further configured to generate an underlying surface body-fitting mesh of the target area based on the underlying surface three-dimensional model, wherein the underlying surface body-fitting mesh supports diffusion simulation of the target area.

[0098] In one implementation, the acquisition unit 801 may also be used to:

[0099] Acquire initial terrain data of the target area, wherein the initial terrain data includes an initial terrain height of each grid point in the target area;

[0100] The processing unit 802 may also be used to:

[0101] Determining the relative terrain height of each grid point based on the initial terrain height of each grid point; and generating a three-dimensional terrain model of the target area based on the relative terrain height of each grid point;

[0102] When the processing unit 802 generates the underlying surface three-dimensional model of the target area based on the target top surface indication data and the side surface indication data of each building, it can be specifically used to:

[0103] The target top surface indication data and side surface indication data of each building and the three-dimensional terrain model are used to generate a three-dimensional model of the underlying surface of the target area.

[0104] In another implementation, when the processing unit 802 generates the three-dimensional terrain model of the target area based on the relative terrain height of each grid point, it can be specifically used to:

[0105] Based on the relative terrain height of each grid point, triangulate the target area to obtain a terrain triangulation result of the target area, wherein the terrain triangulation result includes the grid point coordinates of each grid point and surface representation information of each terrain triangulation surface in a plurality of terrain triangulation surfaces;

[0106] The terrain triangulation result is added to a three-dimensional terrain model file to realize the generation of a three-dimensional terrain model of the target area.

[0107] In another implementation manner, the building indication data of a building includes the contour point coordinates of each building contour point in the corresponding building and the building height indication information of the corresponding building, and the vertex data also includes the index of the vertex of the corresponding building; when the processing unit 802 determines the building vertex indication data of each building based on the building indication data of each building, it can be specifically used to:

[0108] Traverse each building in the target area, and use the currently traversed building as the current building;

[0109] Determine an initial vertex index of the current building, and based on the initial vertex index of the current building, determine an index of each building vertex in the current building;

[0110] Determine the building center point coordinates of the current building based on the contour point coordinates of each building contour point in the current building; and determine the relative ground height of the current building based on the relative terrain heights of each grid point in M ​​grid points corresponding to the building center point coordinates, wherein the M grid points are determined from the grid points included in the target area, and M is a positive integer;

[0111] Determine the vertex coordinates of each building vertex in the current building based on the contour point coordinates of each building contour point in the current building, the relative height to the ground, and the building height indication information of the current building; and add the vertex coordinates and index of each building vertex in the current building to the building vertex indication data of the current building, so that the vertex data of a building vertex in the current building includes the vertex coordinates and index of the corresponding building vertex;

[0112] After traversing each building in the target area, building vertex indication data of each building is obtained.

[0113] In another implementation manner, when the processing unit 802 generates the initial top surface indication data and the side surface indication data of each building based on the building vertex indication data of each building, the processing unit 802 may be specifically configured to:

[0114] For any building in the target area, based on the building vertex indication data of the any building, the side indication data of the any building is generated in the target side link order, wherein the side indication data of the any building includes the surface representation information of each side of the k sides of the any building, and one surface representation information includes the index of each point in a surface, and k is the number of building contour points in the any building;

[0115] From the building vertex indication data of any one of the buildings, the vertex data of each top surface vertex in the top surface of any one of the buildings is determined; and based on the vertex data of each top surface vertex, the top surface of any one of the buildings is triangulated to obtain the initial top surface indication data of any one of the buildings, the initial top surface indication data of any one of the buildings including the surface representation information of each initial top surface triangulation surface of a plurality of initial top surface triangulation surfaces of the top surface of any one of the buildings.

[0116] In another implementation manner, when the processing unit 802 determines the target top surface indication data of each building based on the initial top surface indication data of each building, it can be specifically used to:

[0117] Traversing each of the multiple initial top surface triangulation surfaces of the top surface of any building, and using the currently traversed initial top surface triangulation surface as the current initial top surface triangulation surface;

[0118] Determining the centroid of the current initial top surface triangulation surface based on the surface representation information of the current initial top surface triangulation surface;

[0119] If the centroid of the current initial top surface triangulation surface is located within the top surface of any one of the buildings, then adding the surface representation information of the current initial top surface triangulation surface to the target top surface indication data of any one of the buildings, so that the current initial top surface triangulation surface is used as a target top surface triangulation surface of the top surface of any one of the buildings;

[0120] If the centroid of the current initial top surface triangulation surface is not located within the top surface of any of the buildings, then the surface representation information of the current initial top surface triangulation surface is not added to the target top surface indication data of any of the buildings;

[0121] After traversing each of the multiple initial top surface triangulation surfaces of the top surface of any building, the target top surface indication data of any building is obtained; wherein the target top surface indication data of any building includes the surface representation information of each target top surface triangulation surface of the multiple target top surface triangulation surfaces of the top surface of any building.

[0122] In another implementation, the processing unit 802 may also be used to:

[0123] Determining whether the number of building contour points in any of the buildings is greater than a preset contour point number threshold;

[0124] If the number of building contour points in any of the buildings is greater than the preset contour point number threshold, the process of triangulating the top surface of any of the buildings based on the vertex data of each top surface vertex is triggered to obtain initial top surface indication data of any of the buildings;

[0125] If the number of building contour points in any of the buildings is less than or equal to the preset contour point number threshold, the vertex data of each top surface vertex in the top surface of any of the buildings is used to generate top surface representation information of the building, so as to add the top surface representation information of the building to the initial top surface indication data of the building, and the top surface representation information of the building includes the index of each top surface vertex in the top surface of the building; determining the target top surface indication data of each building based on the initial top surface indication data of each building, includes: using the initial top surface indication data of the building as the target top surface indication data of the building.

[0126] According to one embodiment of the present invention, Figure 8 Each unit in the underlying surface body-fitting grid generation device for high-precision simulation shown can be separately or completely combined into one or several other units to form, or one (some) of the units can be further divided into multiple smaller units in function to form, which can achieve the same operation without affecting the realization of the technical effects of the embodiments of the present invention. The above-mentioned units are divided based on logical functions. In practical applications, the function of one unit can also be realized by multiple units, or the functions of multiple units can be realized by one unit. In other embodiments of the present invention, any underlying surface body-fitting grid generation device for high-precision simulation can also include other units. In practical applications, these functions can also be implemented with the assistance of other units, and can be implemented by the collaboration of multiple units.

[0127] According to another embodiment of the present invention, the program can be executed by running a program on a general electronic device such as a computer including a central processing unit (CPU), a random access memory medium (RAM), a read-only memory medium (ROM), and other processing elements and storage elements. Figure 1 or Figure 2 A computer program (including program code) for each step involved in the corresponding method shown in Figure 8 The computer program can be recorded on a computer storage medium, for example, and loaded into the electronic device through the computer storage medium, and run therein.

[0128] Based on the description of the above method embodiment and device embodiment, the exemplary embodiment of the present invention further provides an electronic device, including: at least one processor; and a memory connected to the at least one processor in communication. The memory stores a computer program that can be executed by the at least one processor, and the computer program is used to enable the electronic device to perform the method according to the embodiment of the present invention when executed by the at least one processor.

[0129] Exemplary embodiments of the present invention also provide a non-transitory computer-readable storage medium storing a computer program, wherein the computer program, when executed by a processor of a computer, is used to cause the computer to perform a method according to an embodiment of the present invention.

[0130] An exemplary embodiment of the present invention further provides a computer program product, comprising a computer program, wherein when the computer program is executed by a processor of a computer, the computer is used to enable the computer to perform a method according to an embodiment of the present invention.

[0131] refer to Fig. 9 , a block diagram of an electronic device 900 that can be used as a server or client of the present invention will now be described, which is an example of a hardware device that can be applied to various aspects of the present invention. The electronic device is intended to represent various forms of digital electronic computer devices, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present invention described and / or required herein.

[0132] like Fig. 9As shown, the electronic device 900 includes a computing unit 901, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 902 or a computer program loaded from a storage unit 908 into a random access memory (RAM) 903. In the RAM 903, various programs and data required for the operation of the electronic device 900 can also be stored. The computing unit 901, the ROM 902, and the RAM 903 are connected to each other via a bus 904. An input / output (I / O) interface 905 is also connected to the bus 904.

[0133] A plurality of components in the electronic device 900 are connected to the I / O interface 905, including: an input unit 906, an output unit 907, a storage unit 908, and a communication unit 909. The input unit 906 may be any type of device capable of inputting information to the electronic device 900, and the input unit 906 may receive input digital or character information, and generate key signal inputs related to user settings and / or function control of the electronic device. The output unit 907 may be any type of device capable of presenting information, and may include, but is not limited to, a display, a speaker, a video / audio output terminal, a vibrator, and / or a printer. The storage unit 908 may include, but is not limited to, a disk, an optical disk. The communication unit 909 allows the electronic device 900 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks, and may include, but is not limited to, a modem, a network card, an infrared communication device, a wireless communication transceiver, and / or a chipset, such as a Bluetooth™ device, a WiFi device, a WiMax device, a cellular communication device, and / or the like.

[0134] The computing unit 901 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 901 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 901 performs the various methods and processes described above. For example, in some embodiments, the underlying surface body-fitting grid generation method for high-precision simulation may be implemented as a computer software program, which is tangibly included in a machine-readable medium, such as a storage unit 908. In some embodiments, part or all of the computer program may be loaded and / or installed on the electronic device 900 via the ROM 902 and / or the communication unit 909. In some embodiments, the computing unit 901 may be configured to perform the underlying surface body-fitting grid generation method for high-precision simulation by any other appropriate means (e.g., by means of firmware).

[0135] The program code for implementing the method of the present invention can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer or other programmable data processing device, so that the program code, when executed by the processor or controller, enables the functions / operations specified in the flow chart and / or block diagram to be implemented. The program code can be executed entirely on the machine, partially on the machine, partially on the machine as a stand-alone software package and partially on a remote machine, or entirely on a remote machine or server.

[0136] In the context of the present invention, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, electronic, magnetic, optical, electromagnetic, infrared, or semiconductor systems, devices, or equipment, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0137] As used herein, the terms "machine-readable medium" and "computer-readable medium" refer to any computer program product, apparatus, and / or device (e.g., disk, optical disk, memory, programmable logic device (PLD)) for providing machine instructions and / or data to a programmable processor, including a machine-readable medium that receives machine instructions as a machine-readable signal. The term "machine-readable signal" refers to any signal for providing machine instructions and / or data to a programmable processor.

[0138] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0139] Furthermore, it should be understood that what is disclosed above is only a preferred embodiment of the present invention, and certainly cannot be used to limit the scope of rights of the present invention. Therefore, equivalent changes made according to the claims of the present invention are still within the scope of the present invention.

Claims

1. A method for generating a body-fitting mesh of an underlying surface for high-precision simulation, characterized in that: include: Acquire target building data of a target area, wherein the target building data includes building indication data of each building in the target area; Determine building vertex indication data of each building based on the building indication data of each building respectively, the building indication data of one building includes the contour point coordinates of each building contour point in the corresponding building and the building height indication information of the corresponding building, the building vertex indication data of one building includes the vertex data of each building vertex in the corresponding building, and one vertex data includes the vertex coordinates of the vertex of the corresponding building; Based on the building vertex indication data of each building, the initial top surface indication data and side surface indication data of each building are generated, including: for any building in the target area, based on the building vertex indication data of any building, the side surface indication data of any building is generated according to the target side surface linking order, the side surface indication data of any building includes the surface representation information of each side surface of k side surfaces of any building, one surface representation information includes the index of each point in a surface, k is the number of building contour points in any building, and the target side surface linking order is clockwise or counterclockwise; from the building vertex indication data of any building, the vertex data of each top surface vertex in the top surface of any building is determined; and based on the vertex data of each top surface vertex, the top surface of any building is triangulated to obtain the initial top surface indication data of any building, the initial top surface indication data of any building includes the surface representation information of each initial top surface triangulation surface of multiple initial top surface triangulation surfaces of the top surface of any building; Determining target top surface indication data of each building based on the initial top surface indication data of each building; Based on the target top surface indication data and the side surface indication data of each building, a three-dimensional model of the underlying surface of the target area is generated, including: using the target top surface indication data and the side surface indication data of each building to generate a three-dimensional building complex model of the target area, and using the three-dimensional building complex model as the three-dimensional model of the underlying surface of the target area; or using the target top surface indication data and the side surface indication data of each building and the three-dimensional terrain model of the target area to generate the three-dimensional model of the underlying surface; Based on the underlying surface three-dimensional model, an underlying surface body-fitting mesh of the target area is generated, and the underlying surface body-fitting mesh supports diffusion simulation of any material in the target area.

2. The method according to claim 1, characterized in that The method further comprises: Acquire initial terrain data of the target area, wherein the initial terrain data includes an initial terrain height of each grid point in the target area; Based on the initial terrain height of each grid point, the relative terrain height of each grid point is determined; and based on the relative terrain height of each grid point, a three-dimensional terrain model of the target area is generated.

3. The method according to claim 2, characterized in that The step of generating a three-dimensional terrain model of the target area based on the relative terrain height of each grid point comprises: Based on the relative terrain height of each grid point, triangulate the target area to obtain a terrain triangulation result of the target area, wherein the terrain triangulation result includes the grid point coordinates of each grid point and surface representation information of each terrain triangulation surface in a plurality of terrain triangulation surfaces; The terrain triangulation result is added to a three-dimensional terrain model file to realize the generation of a three-dimensional terrain model of the target area.

4. The method according to claim 2, characterized in that: One vertex data also includes an index of a corresponding building vertex; and determining the building vertex indication data of each building based on the building indication data of each building, respectively, includes: Traverse each building in the target area, and use the currently traversed building as the current building; Determine an initial vertex index of the current building, and based on the initial vertex index of the current building, determine an index of each building vertex in the current building; Determine the building center point coordinates of the current building based on the contour point coordinates of each building contour point in the current building; and determine the relative ground height of the current building based on the relative terrain heights of each grid point in M ​​grid points corresponding to the building center point coordinates, wherein the M grid points are determined from the grid points included in the target area, and M is a positive integer; Determine the vertex coordinates of each building vertex in the current building based on the contour point coordinates of each building contour point in the current building, the relative height to the ground, and the building height indication information of the current building; and add the vertex coordinates and index of each building vertex in the current building to the building vertex indication data of the current building, so that the vertex data of a building vertex in the current building includes the vertex coordinates and index of the corresponding building vertex; After traversing each building in the target area, building vertex indication data of each building is obtained.

5. The method according to any one of claims 1 to 4, characterized in that: The determining the target top surface indication data of each building based on the initial top surface indication data of each building respectively includes: Traversing each of the multiple initial top surface triangulation surfaces of the top surface of any building, and using the currently traversed initial top surface triangulation surface as the current initial top surface triangulation surface; Determining the centroid of the current initial top surface triangulation surface based on the surface representation information of the current initial top surface triangulation surface; If the centroid of the current initial top surface triangulation surface is located within the top surface of any one of the buildings, then adding the surface representation information of the current initial top surface triangulation surface to the target top surface indication data of any one of the buildings, so that the current initial top surface triangulation surface is used as a target top surface triangulation surface of the top surface of any one of the buildings; If the centroid of the current initial top surface triangulation surface is not located within the top surface of any of the buildings, then the surface representation information of the current initial top surface triangulation surface is not added to the target top surface indication data of any of the buildings; After traversing each of the multiple initial top surface triangulation surfaces of the top surface of any building, the target top surface indication data of any building is obtained; wherein the target top surface indication data of any building includes the surface representation information of each target top surface triangulation surface of the multiple target top surface triangulation surfaces of the top surface of any building.

6. The method according to any one of claims 1 to 4, characterized in that: The method further comprises: Determining whether the number of building contour points in any of the buildings is greater than a preset contour point number threshold; If the number of building contour points in any of the buildings is greater than the preset contour point number threshold, the process of triangulating the top surface of any of the buildings based on the vertex data of each top surface vertex is triggered to obtain initial top surface indication data of any of the buildings; If the number of building contour points in any of the buildings is less than or equal to the preset contour point number threshold, the vertex data of each top surface vertex in the top surface of any of the buildings is used to generate top surface representation information of the building, so as to add the top surface representation information of the building to the initial top surface indication data of the building, and the top surface representation information of the building includes the index of each top surface vertex in the top surface of the building; determining the target top surface indication data of each building based on the initial top surface indication data of each building, includes: using the initial top surface indication data of the building as the target top surface indication data of the building.

7. A device for generating underlying surface body-fitting grids for high-precision simulation, characterized in that: The device comprises: An acquisition unit, configured to acquire target building data of a target area, wherein the target building data includes building indication data of each building in the target area; A processing unit, configured to determine building vertex indication data of each building based on the building indication data of each building, respectively, wherein the building indication data of one building includes the contour point coordinates of each building contour point in the corresponding building and the building height indication information of the corresponding building, and the building vertex indication data of one building includes the vertex data of each building vertex in the corresponding building, and one vertex data includes the vertex coordinates of the vertex of the corresponding building; The processing unit is further used to generate initial top surface indication data and side surface indication data of each building based on the building vertex indication data of each building, including: for any building in the target area, based on the building vertex indication data of any building, generating the side surface indication data of any building in the target side surface link order, wherein the side surface indication data of any building includes the surface representation information of each side surface of the k side surfaces of any building, one surface representation information includes the index of each point in a surface, k is the number of building contour points in the any building, and the target side surface link order is In a clockwise order or a counterclockwise order; from the building vertex indication data of any building, determine the vertex data of each top surface vertex in the top surface of any building; and based on the vertex data of each top surface vertex, triangulate the top surface of any building to obtain the initial top surface indication data of any building, the initial top surface indication data of any building includes the surface representation information of each initial top surface triangulation surface of the top surface of any building; and based on the initial top surface indication data of each building, determine the target top surface indication data of each building; The processing unit is further used to generate a three-dimensional model of the underlying surface of the target area based on the target top surface indication data and the side surface indication data of each building, including: using the target top surface indication data and the side surface indication data of each building to generate a three-dimensional building complex model of the target area, and using the three-dimensional building complex model as the three-dimensional model of the underlying surface of the target area; or using the target top surface indication data and the side surface indication data of each building and the three-dimensional terrain model of the target area to generate the three-dimensional model of the underlying surface; The processing unit is further used to generate an underlying surface body-fitting mesh of the target area based on the underlying surface three-dimensional model, wherein the underlying surface body-fitting mesh supports diffusion simulation of any substance in the target area.

8. An electronic device, characterized in that: include: processor; as well as Memory for storing programs, The program includes instructions, which, when executed by the processor, cause the processor to perform the method according to any one of claims 1 to 6.

9. A non-transitory computer-readable storage medium storing computer instructions, wherein: The computer instructions are used to make a computer execute the method according to any one of claims 1-6.

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