Three-dimensional extended global mesh partitioning method and system based on spatial octree

Abstract

This application provides a three-dimensional extended global grid partitioning method and system based on a spatial octree, relating to the field of global grid partitioning. The method includes: constructing a basic spatial structure with consistent latitude and longitude spans for the Earth; recursively partitioning the Earth along the longitude and latitude dimensions to construct a multi-level grid structure; performing extended mapping processing on the altitude domain to construct a unified three-dimensional spatial representation system of longitude, latitude, and altitude; and simultaneously performing bisection recursive partitioning of the three-dimensional spatial units to construct a three-dimensional grid system adapted to the spatial octree structure; further, using a bitwise interpolation encoding method to fuse and encode the longitude, latitude, and altitude indices to obtain the grid code of the three-dimensional grid unit, and establishing parent-child mapping relationships between different levels of grids to obtain the global grid partitioning result. This application, used in the global grid partitioning process, solves the technical problem of existing technologies struggling to achieve spatially coordinated and unified expression in global grid partitioning.

Description

Technical Field

[0001] This application relates to the field of global mesh generation, and in particular to a three-dimensional extended global mesh generation method and system based on spatial octrees. Background Technology

[0002] With the development of the low-altitude economy, smart cities, and global spatial information services, the demand for unified and efficient global three-dimensional spatial grid representation is constantly increasing. Constructing a stable and reliable spatial partitioning method is crucial for improving spatial data organization and processing capabilities. Current technologies typically employ latitude and longitude-based two-dimensional grid partitioning to discretize geospatial data, and then manage the space at multiple scales through hierarchical subdivision or spatial indexing structures, combined with simple coding methods for grid positioning and retrieval. However, in practical applications, these methods often suffer from inconsistent partitioning standards across different dimensions and a lack of overall consistency in spatial representation. This leads to inconsistencies in the organization and computation of the three-dimensional spatial structure, consequently affecting spatial data processing efficiency and application effectiveness. Therefore, existing technologies face the technical challenge of achieving a unified and coordinated spatial representation in global grid partitioning. Summary of the Invention

[0003] This application provides a three-dimensional extended global mesh generation method and system based on spatial octrees, which solves the technical problem that existing technologies have difficulty in achieving spatially coordinated and unified expression in global mesh generation.

[0004] To achieve the above objectives, this application adopts the following technical solution: Firstly, a three-dimensional extended global grid partitioning method based on a spatial octree is provided, comprising: performing hemispherical pre-partitioning of the Earth's latitude and longitude space to construct a basic space with consistent latitude and longitude spans; based on the basic space, performing recursive partitioning in the longitude and latitude dimensions to construct a multi-level grid structure; based on the multi-level grid structure, performing extended mapping processing on the altitude domain to construct a unified three-dimensional spatial expression system of longitude, latitude, and altitude; based on the unified three-dimensional spatial expression system of longitude, latitude, and altitude, performing synchronous binary recursive partitioning of the three-dimensional spatial units to construct a three-dimensional grid system adapted to the spatial octree structure; based on the three-dimensional grid system, using a bitwise interpolation encoding method to fuse and encode the longitude, latitude, and altitude indices to obtain the grid code of the three-dimensional grid unit; the grid code of the three-dimensional grid unit includes a hierarchical identifier; based on the grid code of the three-dimensional grid unit, establishing a parent-child mapping relationship between different levels of grids to obtain the global grid partitioning result.

[0005] In conjunction with the first aspect mentioned above, one possible implementation involves pre-dividing the Earth's latitude and longitude space into hemispherical segments to construct a basic space with consistent latitude and longitude spans. This includes pre-dividing the Earth's latitude and longitude space into hemispherical segments, dividing the longitude range into western and eastern hemisphere intervals, so that the longitude span of a single hemisphere is consistent with the latitude span, thus constructing a basic space with consistent latitude and longitude spans.

[0006] In conjunction with the first aspect mentioned above, one possible implementation involves recursively partitioning the base space along the longitude and latitude dimensions to construct a multi-level grid structure. This includes: recursively partitioning the base space along the longitude and latitude dimensions using a bisection method to construct a multi-level grid; maintaining a two-fold ratio between adjacent levels of the multi-level grid to form a multi-level two-dimensional grid structure with a clear parent-child hierarchical mapping relationship.

[0007] In conjunction with the first aspect mentioned above, in one possible implementation, based on a multi-level grid structure, the height domain is extended and mapped to construct a three-dimensional unified spatial expression system of longitude, latitude, and height. This includes: based on the multi-level grid structure, mapping the height dimension to a first interval according to a preset ratio, so that the physical size of the height dimension is consistent with the physical size of the latitude direction, thereby constructing a three-dimensional unified spatial expression system of longitude, latitude, and height.

[0008] In conjunction with the first aspect mentioned above, in one possible implementation, the first interval range is greater than or equal to zero degrees and less than or equal to ninety degrees.

[0009] In conjunction with the first aspect mentioned above, one possible implementation involves using a unified three-dimensional spatial representation system based on longitude, latitude, and altitude. This system performs synchronous bisection recursive partitioning of three-dimensional spatial units to construct a three-dimensional mesh system adapted to a spatial octree structure. This includes: using three-dimensional spatial units composed of longitude, latitude, and altitude as initial mesh units; in each recursive level, synchronously bisecting the current mesh unit along the longitude, latitude, and altitude dimensions, dividing the current mesh unit into eight sub-mesh units; assigning a corresponding three-dimensional spatial index position to each sub-mesh unit to identify its relative spatial orientation within the parent mesh unit; repeatedly performing the bisection recursive partitioning operation on the sub-mesh units until a preset level depth or target spatial resolution requirement is reached; and during the recursive partitioning process, establishing a one-to-one correspondence between parent and sub-mesh units according to the partitioning levels to obtain a hierarchical three-dimensional mesh system that satisfies the spatial octree structure.

[0010] In conjunction with the first aspect mentioned above, in one possible implementation, based on a three-dimensional grid system, a bitwise interpolation encoding method is used to fuse and encode the longitude, latitude, and altitude indices to obtain the grid code of the three-dimensional grid unit. This includes: traversing the discretized index values ​​corresponding to the longitude, latitude, and altitude dimensions of the three-dimensional grid unit in the three-dimensional grid system, including the longitude index, latitude index, and altitude index; converting the longitude index, latitude index, and altitude index into binary representation sequences of equal length; interleaving the binary representation sequences of the longitude index, latitude index, and altitude index according to a preset bitwise interpolation rule, so that the binary bits of different dimensions are combined alternately to obtain an interleaved binary sequence; concatenating the interleaved binary sequence to obtain the Morton code sequence; the Morton code sequence is used to represent the three-dimensional spatial position; and combining the Morton code sequence with the corresponding hierarchical identifier to obtain the grid code of the three-dimensional grid unit.

[0011] In conjunction with the first aspect mentioned above, in one possible implementation, after obtaining the global grid subdivision results, the method further includes calculating the physical dimensions of the three-dimensional grid cells based on latitude information, including: obtaining the latitude value and Earth radius parameter corresponding to the target three-dimensional grid cell; calculating the equatorial latitude length based on the Earth radius parameter; calculating the latitude length at the target latitude based on the latitude value; mapping the latitude length to the grid angle span based on the longitude and latitude span of the current grid level to obtain the actual physical dimensions of the grid cell in the longitude and latitude directions; and determining the spatial physical scale information of the three-dimensional grid cell based on the physical dimensions in the longitude and latitude directions.

[0012] Secondly, a three-dimensional extended global meshing system based on a spatial octree is provided. The system includes: a hemispherical pre-meshing module, a two-dimensional recursive meshing module, a height domain mapping module, a three-dimensional mesh construction module, an encoding generation module, and a hierarchical mapping module. The system comprises the following modules: a hemispherical pre-partitioning module for pre-partitioning the Earth's latitude and longitude space to construct a basic space with consistent latitude and longitude spans; a two-dimensional recursive partitioning module for recursively partitioning the basic space along the longitude and latitude dimensions to construct a multi-level grid structure; a height domain mapping module for extending and mapping the height domain based on the multi-level grid structure to construct a unified three-dimensional spatial representation system of longitude, latitude, and height; a three-dimensional grid construction module for synchronously bisectioning and recursively partitioning three-dimensional spatial units based on the unified three-dimensional spatial representation system of longitude, latitude, and height to construct a three-dimensional grid system adapted to a spatial octree structure; an encoding generation module for fusing and encoding the longitude, latitude, and height indices using bitwise interpolation based on the three-dimensional grid system to obtain the grid code of the three-dimensional grid unit; the grid code of the three-dimensional grid unit includes a hierarchical identifier; and a hierarchical mapping module for establishing parent-child mapping relationships between different levels of grids based on the grid code of the three-dimensional grid unit to obtain the global grid partitioning results.

[0013] In conjunction with the second aspect mentioned above, in one possible implementation, the hemispherical pre-segmentation module is also used to: perform hemispherical pre-segmentation processing on the Earth's latitude and longitude space, divide the longitude range into the western hemisphere interval and the eastern hemisphere interval, so that the longitude span of a single hemisphere is consistent with the span of the latitude range, and construct a basic space with consistent longitude and latitude span.

[0014] This application provides a three-dimensional extended global grid partitioning method and system based on a spatial octree. It pre-partitions the Earth's latitude and longitude space into a hemispherical structure and constructs a basic space with consistent latitude and longitude spans. Based on this, it combines two-dimensional recursive partitioning of latitude and longitude with height dimension mapping extension to achieve a unified expression of the three-dimensional space of longitude, latitude, and height. Furthermore, it constructs a three-dimensional grid system adapted to the spatial octree structure through synchronous binary recursion. Simultaneously, it combines bitwise interpolation encoding to achieve efficient expression and hierarchical association of three-dimensional spatial positions, resulting in a well-structured and regular grid structure. Compared to existing technologies, this application effectively improves the structural coordination and expression consistency of three-dimensional spatial partitioning, enhances the ability to express the relationships between different levels of grids, and has higher processing efficiency and scalability in spatial indexing, data organization, and computation. It is suitable for the high-efficiency computational needs of complex spatial scenarios and solves the technical problem of difficulty in achieving spatially coordinated and unified expression in existing global grid partitioning technologies.

[0015] It should be understood that the descriptions of technical features, technical solutions, beneficial effects, or similar language in this application do not imply that all features and advantages can be achieved in any single embodiment. Rather, it is understood that the description of a feature or beneficial effect means that a specific technical feature, technical solution, or beneficial effect is included in at least one embodiment. Therefore, the descriptions of technical features, technical solutions, or beneficial effects in this specification do not necessarily refer to the same embodiment. Furthermore, the technical features, technical solutions, and beneficial effects described in this embodiment can be combined in any suitable manner. Those skilled in the art will understand that embodiments can be implemented without one or more specific technical features, technical solutions, or beneficial effects of a particular embodiment. In other embodiments, additional technical features and beneficial effects may be identified in specific embodiments that do not embody all embodiments. Attached Figure Description

[0016] Figure 1 A system architecture diagram of a three-dimensional extended global mesh partitioning system based on a spatial octree is provided for embodiments of this application; Figure 2 A flowchart illustrating a three-dimensional extended global mesh generation method based on a spatial octree, provided for an embodiment of this application; Figure 3 This is a schematic diagram of the basic space construction provided for an embodiment of this application; Figure 4 A schematic diagram of a 20-22 level multi-level mesh structure provided in an embodiment of this application; Figure 5 This is a schematic diagram illustrating the principle of height domain partitioning in an embodiment of this application. Figure 6 A schematic diagram illustrating the principle of calculating the physical dimensions of the longitude direction provided in the embodiments of this application; Figure 7 A flowchart illustrating another three-dimensional extended global mesh generation method based on a spatial octree provided in this application embodiment; Figure 8 This is a flowchart illustrating another three-dimensional extended global mesh generation method based on a spatial octree, provided in an embodiment of this application. Detailed Implementation

[0017] In the description of this application, unless otherwise stated, " / " means "or," for example, A / B can mean A or B. The "and / or" in this document is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, and B alone. Furthermore, "at least one" means one or more, and "multiple" means two or more. The terms "first," "second," etc., do not limit the quantity or order of execution, and "first," "second," etc., do not necessarily imply differences.

[0018] It should be noted that, in this application, the terms "exemplary" or "for example" are used to indicate that something is being described as an example, illustration, or illustration. Any embodiment or design described as "exemplary" or "for example" in this application should not be construed as being more preferred or advantageous than other embodiments or design solutions. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0019] The three-dimensional extended global mesh generation method based on spatial octrees provided in this application can be applied to, for example... Figure 1 In the spatial octree-based 3D extended global mesh partitioning system shown, such as Figure 1 As shown, the system includes: a hemispherical pre-partitioning module 101, a two-dimensional recursive partitioning module 102, a height domain mapping module 103, a three-dimensional mesh construction module 104, an encoding generation module 105, and a hierarchical mapping module 106; Among them, the hemispherical pre-segmentation module 101 is used to perform hemispherical pre-segmentation processing on the Earth's latitude and longitude space to construct a basic space with consistent latitude and longitude spans; The two-dimensional recursive partitioning module 102 is used to perform recursive partitioning based on the base space in the longitude and latitude dimensions to construct a multi-level grid structure. The height domain mapping module 103 is used to perform extended mapping processing on the height domain based on a multi-level grid structure, and to construct a three-dimensional unified spatial expression system of longitude, latitude and height. The 3D mesh construction module 104 is used to synchronously and recursively divide 3D spatial units based on a unified 3D spatial representation system of longitude, latitude and altitude, and construct a 3D mesh system adapted to the spatial octree structure. The encoding generation module 105 is used to fuse the longitude, latitude and altitude indices according to the three-dimensional grid system using a bit-by-bit interpolation encoding method to obtain the grid code of the three-dimensional grid cell; the grid code of the three-dimensional grid cell includes a hierarchical identifier. The hierarchical mapping module 106 is used to establish parent-child mapping relationships between different levels of meshes based on the mesh encoding of three-dimensional mesh units, and to obtain global mesh subdivision results.

[0020] To address the technical problem of difficulty in achieving spatially coordinated and unified representation in existing global grid partitioning technologies, this application provides a three-dimensional extended global grid partitioning method based on a spatial octree.

[0021] Figure 2 This is a flowchart illustrating the three-dimensional extended global mesh generation method based on spatial octrees provided in an embodiment of this application, as shown below. Figure 2 As shown, the method includes: S201. Perform hemispherical pre-division processing on the Earth's latitude and longitude space to construct a basic space with consistent latitude and longitude spans.

[0022] Among them, hemispheric pre-division refers to dividing the global longitude range into two independent spatial regions, the Eastern Hemisphere and the Western Hemisphere, based on longitude as the dividing benchmark; consistent longitude and latitude span means that within a single hemisphere, the length of the longitude range and the length of the latitude range remain the same on the angular scale, thus forming a regular rectangular space.

[0023] In one possible implementation, the latitude and longitude ranges in a standard geographic coordinate system are obtained, with the longitude range being [-180°, 180°] and the latitude range being [-90°, 90°]. Using the 0° meridian as the dividing line, the longitude is divided into two intervals: [-180°, 0°] and [0°, 180°]. These two intervals are then combined with the complete latitude range [-90°, 90°] to construct two basic spatial units. An independent spatial index is established for each basic spatial unit, and its coordinate origin and direction are uniformly defined, ensuring that the two hemispherical spaces have a consistent data structure and processing method in subsequent processing. Finally, two basic spaces with consistent latitude and longitude spans are output.

[0024] It should be noted that this hemispheric division only changes the way longitude is organized, without changing the physical meaning of the original geographic coordinates; the Earth's latitude and longitude space is pre-divided into hemispheres, dividing the longitude range into the western hemisphere and the eastern hemisphere, so that the longitude span of a single hemisphere is consistent with the latitude span, thus constructing a basic space with consistent longitude and latitude spans.

[0025] As an example, Figure 3 A schematic diagram of the basic space construction provided for the embodiments of this application, such as Figure 3As shown, in a standard geographic coordinate system, with 0° longitude as the dividing line, the global longitude range from -180° to 180° is divided into two symmetrical regions: the left side is the Western Hemisphere (labeled 0, corresponding to a longitude range of -180° to 0°), and the right side is the Eastern Hemisphere (labeled 1, corresponding to a longitude range of 0° to 180°); simultaneously, both sides maintain a complete latitude range of -90° to 90°. Through this division, the longitude span of each hemisphere is 180°, perfectly consistent with the 180° latitude span, thus forming a regular rectangular space of "180° × 180°" within each hemisphere.

[0026] This step employs a hemispherical pre-partitioning design to address the core challenge of non-square grid physical dimensions near the equator. It divides the Earth into two equal hemispheres along the longitude direction, ensuring that the longitude span of each hemisphere is 180°, matching the full latitude span. This guarantees consistent longitude and latitude span dimensions from the outset, adapting to spatial octree storage logic and laying the foundation for efficient subsequent encoding and storage. This differs from existing technologies that lack hemispherical partitioning, resulting in mismatched longitude and latitude spans.

[0027] S202. Based on the basic space, recursively partition the space along the longitude and latitude dimensions to construct a multi-level grid structure.

[0028] Among them, recursive subdivision refers to the process of repeatedly dividing the current spatial unit into multiple sub-units according to fixed rules; multi-level mesh structure refers to a hierarchical mesh set composed of different subdivision levels, where each level corresponds to a different spatial resolution.

[0029] In one possible implementation, a hemispherical base space is used as the initial grid unit, with its longitude and latitude ranges treated as two independent dimensions. Within each level, the current grid unit is equally divided along both the longitude and latitude directions, generating multiple sub-grid units. A unique two-dimensional index (such as a row or column index) is assigned to each sub-grid. The same partitioning operation is performed on each sub-grid until a preset level depth or target spatial resolution is reached. During the recursive process, the index relationships and spatial range information of each level of grid are recorded, ultimately forming a complete multi-level grid structure. The grid sizes of adjacent levels in the multi-level grid maintain a two-fold ratio, forming a multi-level two-dimensional grid structure with a clear parent-child hierarchical mapping relationship.

[0030] It should be noted that in actual implementation, each level of the grid should be stored using a unified data structure, such as a hierarchical index table based on an array or tree structure, to facilitate quick location and query; at the same time, it is necessary to ensure that there are no overlapping or missing areas during the partitioning process.

[0031] As an example, Figure 4This is a schematic diagram of a 20-22 level multi-level mesh structure provided in an embodiment of this application, as shown below. Figure 4 As shown, starting with a basic space of "180°×180°" for a single hemisphere as the initial grid (L20 level), it is bisected simultaneously in both longitude and latitude directions, dividing it into four equal-scale sub-grids to form a higher level (L21). The same bisecting operation is then performed on a specific sub-grid to obtain a finer grid unit (L22). The diagram illustrates the progressive relationship between L20, L21, and L22 through a progressively enlarged view. Meanwhile, the labels "180×2^(-20)°, 180×2^(-21)°, 180×2^(-22)°" at the top indicate that as the level increases, the grid side length decreases by a power of 2. That is, with each level increase, the grid size shrinks to half the size of the previous level, thus ensuring a strict 2:1 scale relationship between adjacent levels. The dashed lines in the figure not only reflect the spatial distribution of the grid, but also intuitively reflect the inclusion relationship between the parent and child grids. This allows for quick mapping and conversion between coarse-grained and fine-grained grids through simple hierarchical indexing, avoiding the complex scale conversion problems in traditional non-standard meshing methods.

[0032] Based on the above steps, this step employs a bisection method to perform layer-by-layer subdivision of the two hemispheres. The core objective is to clarify the dimensional relationships and mapping logic between adjacent grid levels, addressing the problems of complex cross-level mapping calculations and low computational efficiency in existing technologies. Specifically, the hemispherical subdivision scheme ensures the consistency of the latitude and longitude spans of the eastern and western hemispheres, providing a uniform base grid for the bisection method. By simultaneously performing bisection on the latitude and longitude dimensions of each hemisphere, the grid sizes between adjacent levels always maintain a 2:1 ratio (the size of the upper-level grid is twice that of the lower-level grid). Furthermore, this bisection method is highly compatible with the core principles of Morton coding, enabling efficient storage of grid codes through bit-by-bit interpolation, significantly improving storage space utilization, simplifying the coding read / write process, supporting subsequent real-time spatial calculations, and providing a clear logical basis for the rapid conversion between coarse-grained and fine-grained grids.

[0033] S203. Based on a multi-level grid structure, the height domain is extended and mapped to construct a three-dimensional unified spatial representation system of longitude, latitude and height.

[0034] Among them, the height domain extension mapping refers to converting the real physical height value into a normalized representation consistent with the latitude and longitude angle scale; the three-dimensional unified spatial expression system refers to the spatial structure that describes longitude, latitude and height information simultaneously under the same coordinate system.

[0035] In one possible implementation, the range of height values ​​is first determined, such as the maximum height range above the Earth's surface and underground. Based on the Earth's radius and the physical scale corresponding to latitude and longitude, the height values ​​are mapped proportionally to a preset angle range (e.g., [0°, 90°]). The mapped height values ​​are used as the third dimension, and together with the original longitude and latitude, they construct a three-dimensional coordinate system. The three-dimensional coordinate system is then uniformly normalized to ensure that the three dimensions are consistent in terms of numerical range and scale. Finally, a three-dimensional spatial model expressing longitude, latitude, and height in a unified manner is obtained.

[0036] It should be noted that the height mapping ratio should be adjusted according to the specific application scenario to take into account the resolution requirements of ground, low-altitude and underground spaces; at the same time, the mapping function should be guaranteed to be a monotonic function to ensure that the spatial positional relationship is not confused.

[0037] As an example, Figure 5 This is a schematic diagram of the height domain subdivision principle provided in an embodiment of this application, such as... Figure 5 As shown, based on the Earth's radius and the physical scale corresponding to latitude and longitude, the altitude domain is precisely mapped to the range of [0°, 90°] according to the proportion of half the length of the meridian, so that the physical size and span mapping relationship of the altitude domain is completely consistent with the physical size and span mapping relationship of the latitude direction, and together with the original longitude and latitude, a three-dimensional coordinate system is constructed.

[0038] Based on the above steps, this step aims to achieve deep integration of the altitude domain and latitude / longitude dimensions in encoding. This addresses the shortcomings of existing technologies where altitude domain and latitude / longitude encoding are independent, cannot be adapted to octree storage, and result in storage redundancy. This application uses precise calculations based on the actual physical dimensions of the Earth and adopts a design scheme of altitude domain expansion and mapping to achieve deep integration of the altitude domain and latitude / longitude dimensions. This breaks the limitation of independent altitude domain encoding in existing technologies, ensures the uniformity of the geometric characteristics of the mesh in three-dimensional space, further adapts to spatial octree storage logic, reduces data storage redundancy, and provides accurate mesh support for three-dimensional spatial calculations required for scenarios such as low-altitude economic airspace management and UAV route planning.

[0039] S204. Based on a unified three-dimensional spatial representation system of longitude, latitude and altitude, three-dimensional spatial units are synchronously bisected and recursively partitioned to construct a three-dimensional mesh system adapted to a spatial octree structure.

[0040] Among them, synchronous binary recursive partitioning refers to performing equal division operations on the three dimensions of the three-dimensional space at the same time in each level; spatial octree structure refers to a three-dimensional hierarchical structure in which each parent node corresponds to 8 child nodes.

[0041] In one possible implementation, a three-dimensional spatial unit is used as the initial node. In each recursive level, the current space is bisected along the three directions of longitude, latitude, and altitude, dividing it into 8 sub-units. A three-dimensional index identifier is assigned to each sub-unit to represent its relative position in the parent node. The sub-unit is then used as a new node to continue performing the same partitioning operation until the preset level or resolution requirement is reached. Throughout the process, the hierarchical relationship between nodes and spatial boundary information are recorded, ultimately forming a complete octree structure three-dimensional mesh system.

[0042] Based on the above steps, this step constructs a standard octree structure, which enables the three-dimensional space to have a clear hierarchical relationship and a regular division method, which is conducive to improving the organization efficiency of spatial data and the three-dimensional query and analysis capabilities.

[0043] S205. Based on the three-dimensional grid system, the longitude, latitude and altitude indices are fused and encoded using a bitwise interpolation encoding method to obtain the grid code of the three-dimensional grid cell.

[0044] Bitwise interpolation coding refers to a method of combining binary representations of multiple dimensions bitwise in an interleaved manner to form a single coding sequence; grid coding is a digital sequence used to uniquely identify a three-dimensional grid cell, and the grid code of a three-dimensional grid cell includes a hierarchical identifier.

[0045] In one possible implementation, the discrete index values ​​of the target 3D mesh unit in the three dimensions of longitude, latitude, and altitude are obtained; the three index values ​​are converted into binary sequences of equal length; the corresponding bits of each sequence are extracted in a preset order and interleaved to form a new binary sequence; this sequence is used as a spatial location code and combined with the current mesh level information to generate a complete mesh code; finally, the encoding result used to uniquely identify the 3D mesh unit is output.

[0046] Based on the above steps, this step achieves efficient identification of three-dimensional spatial units by integrating multi-dimensional spatial indexes into a single code, which is beneficial to improving spatial indexing speed and data storage compactness.

[0047] S206. Based on the mesh encoding of three-dimensional mesh units, establish the parent-child mapping relationship between different levels of mesh to obtain the global mesh subdivision results.

[0048] The parent-child mapping relationship refers to the containment relationship between different levels of meshes, where the upper-level mesh is the parent node and the lower-level mesh is the child node.

[0049] In one possible implementation, based on the hierarchical identifier of the 3D mesh code, the code is segmented and parsed to extract its hierarchical information; by truncating or expanding the code sequence, the conversion between different levels is realized; the lower-level code is used as a subset of the higher-level code to establish the correspondence between parent and child nodes; the hierarchical relationship of all mesh units is organized to form a complete hierarchical mapping structure; and finally, the global mesh partitioning result containing multi-level relationships is output.

[0050] It should be noted that the establishment of parent-child relationships should be consistent with the encoding rules to ensure the correctness of the hierarchical conversion process; at the same time, index tables or tree structures can be used to store the mapping relationships to improve query efficiency.

[0051] Based on the above steps, this step realizes rapid mapping and conversion between multi-level grids, enabling efficient association and retrieval of spatial data with different precision, thereby improving the overall spatial data processing efficiency.

[0052] In one possible implementation, after S206, the three-dimensional extended global grid partitioning method based on spatial octree provided in this application embodiment further includes calculating the physical size of the three-dimensional grid cell based on latitude information, including: obtaining the latitude value and Earth radius parameter corresponding to the target three-dimensional grid cell; calculating the equatorial latitude length based on the Earth radius parameter; calculating the latitude length at the target latitude based on the latitude value; mapping the latitude length to the grid angle span based on the longitude span and latitude span of the current grid level to obtain the actual physical size of the grid cell in the longitude and latitude directions; and determining the spatial physical scale information of the three-dimensional grid cell based on the physical size in the longitude and latitude directions.

[0053] As an example, Figure 6 This is a schematic diagram illustrating the principle of calculating the physical dimensions in the longitude direction provided in the embodiments of this application, such as... Figure 6 As shown, to address the problem in existing technologies where grid size calculation relies on a three-stage reverse derivation involving degrees, minutes, and seconds, resulting in excessive computational power consumption, this application designs a simple and efficient grid physical size calculation logic based on the correspondence between latitude and geophysical perimeter. Combined with the formula, the actual grid size can be directly derived without the need for cumbersome reverse expansion. Specifically, let the Earth's radius be R (commonly R≈6371km), and the target latitude be... The formula for the length of the equatorial parallel of latitude is: (Common value is approximately 40030 km); Latitude The formula for the length of the weft loop is: By combining the longitude and latitude span of the current grid level and substituting them into the above formula, the actual physical size of the grid can be directly obtained. This logic is simple and efficient, greatly reducing computing power consumption, significantly improving real-time spatial computing performance, and adapting to the needs of low-altitude economic scenarios.

[0054] Preferably, through the above steps S201 to S206, this application designs a 32-level multi-precision hierarchical adaptation scheme. Table 1 is a 32-level grid size mapping table provided in the embodiments of this application. As shown in Table 1, Table 1 clearly presents the correspondence between the span of each level of grid and its physical size, covering the full scale range from the Earth's radius to approximately 5 millimeters. Moreover, the span of each level of grid remains consistent in the three dimensions of longitude, latitude, and altitude, ensuring the uniformity of geometric characteristics of different levels of grid. At the same time, this 32-level hierarchical design can flexibly select the appropriate grid level according to the precision requirements of different low-altitude economic application scenarios. For macro-level airspace management, a coarse-grained level (low-level) grid can be selected, while for high-precision scenarios such as UAV route planning, a fine-grained level (high-level) grid can be selected, achieving a balance between high precision and high real-time performance, and adapting to the needs of multi-scenario applications and cross-platform data sharing.

[0055] Table 1. 32-level mesh size mapping table

[0056] This application achieves the unification of spatial structure and coding representation by constructing a three-dimensional integrated grid subdivision and coding system of longitude, latitude and altitude; at the same time, it improves the consistency and processing efficiency of spatial data organization and reduces system complexity by combining a regularized hierarchical subdivision and coding mapping mechanism, thereby realizing the efficient expression and management of multi-dimensional space and solving the technical problem of the difficulty in achieving spatial coordination and unified expression in the existing technology of global grid subdivision.

[0057] In one possible implementation of the embodiments of this application, combined with Figure 2 ,like Figure 7 As shown, the above S204 can be specifically implemented through the following S701 to S705, which are explained in detail below: S701 uses three-dimensional spatial units consisting of longitude, latitude, and altitude as the initial grid units.

[0058] Among them, a three-dimensional spatial unit refers to a spatial volume jointly defined by a longitude range, a latitude range, and an altitude range; the initial grid unit refers to the uppermost three-dimensional spatial region defined before the recursive partitioning begins.

[0059] In one possible implementation, the longitude range, latitude range, and altitude range after altitude mapping are obtained to construct a unified three-dimensional coordinate space; the entire three-dimensional space is used as the initial grid unit and an initial level identifier is assigned to it; at the same time, the boundary values ​​of the spatial unit in the three dimensions (such as the upper and lower bounds of longitude, latitude, and altitude) are recorded; the three-dimensional index starting point of the initial grid unit (such as all index values ​​being 0) is established and used as the input node for subsequent recursive subdivision.

[0060] It should be noted that the initial mesh cells must have consistent spans in three dimensions or meet a preset proportional relationship to ensure the geometric consistency of sub-mesh cells in the subsequent subdivision process.

[0061] Based on the above steps, this step defines a unified three-dimensional initial spatial unit, ensuring that the subsequent subdivision process is carried out under the same spatial reference, thus guaranteeing the consistency and integrity of the three-dimensional spatial division.

[0062] S702. In each recursive level, the current grid cell is synchronously bisected along the longitude, latitude, and altitude dimensions, dividing the current grid cell into eight sub-grid cells.

[0063] In one possible implementation, for the current grid cell, the midpoint value of its longitude, latitude and altitude are calculated respectively; using the midpoint as the boundary, each dimension is divided into two sub-intervals; through the combination of the three dimensions, eight sub-grid cells are generated, each sub-grid corresponding to a unique three-dimensional spatial range; the eight generated sub-grid cells are output as candidate nodes for the next level.

[0064] It should be noted that the division ratio of the three dimensions must be consistent during the division process to avoid uneven division of one dimension leading to irregular subgrid shapes.

[0065] Based on the above steps, this step uses a synchronous binary search operation to uniformly subdivide the three-dimensional space in each dimension, ensuring that the mesh division rules are consistent and the structure is stable.

[0066] S703. Assign a corresponding three-dimensional spatial index position to each sub-mesh unit to identify the relative spatial orientation of each sub-mesh unit in the parent mesh unit.

[0067] Among them, the three-dimensional spatial index position refers to the discrete identifier used to identify the position of the sub-mesh in the parent mesh, which is generally composed of the relative positions in three dimensions.

[0068] In one possible implementation, for each subgrid cell, a binary identifier is assigned according to its position in the intervals of longitude, latitude, and altitude (e.g., 0 for the lower interval and 1 for the higher interval); the identifiers of the three dimensions are combined to form a three-dimensional index value (e.g., 000 to 111); this index value is used as the encoding of the relative position of the subgrid in the parent grid and is stored in association with the parent node index.

[0069] It should be noted that the index allocation rules must be consistent throughout the system to ensure the correctness of subsequent encoding and mapping processes; at the same time, duplicate or conflicting encodings should be avoided.

[0070] Based on the above steps, this step achieves a structured representation of the three-dimensional spatial location by assigning standardized spatial indexes to the sub-grids, which is beneficial for subsequent encoding and rapid positioning.

[0071] S704. Repeatedly perform the binary recursive subdivision operation on the sub-mesh cells until the preset level depth or target spatial resolution requirement is reached.

[0072] In one possible implementation, the sub-mesh element is used as a new input node, and the three-dimensional synchronous binary search operation is repeatedly performed on each sub-mesh. During each recursion, the current level number is recorded, and it is determined whether the preset maximum level or minimum size threshold has been reached. When the termination condition is met, the subdivision is stopped, and the current mesh element is output as the final leaf node; otherwise, the recursive processing of the next level continues.

[0073] Based on the above steps, this step achieves flexible adjustment of spatial resolution through a controllable recursive partitioning mechanism, meeting the spatial representation requirements under different precision needs.

[0074] S705. During the recursive subdivision operation, a one-to-one correspondence between parent and child mesh units is established according to the subdivision level to obtain a hierarchical three-dimensional mesh system that satisfies the spatial octree structure.

[0075] In one possible implementation, during each recursive partitioning process, the current grid cell is taken as the parent node, and the 8 sub-grid cells obtained from its partitioning are recorded as child nodes; by establishing the association pointers or index relationships between the parent node and the child nodes, all nodes are organized into a tree structure; at the same time, the hierarchical information and spatial range of each node are recorded; finally, a complete hierarchical structure from the root node to the leaf node is formed.

[0076] Based on the above steps, this step establishes a clear parent-child hierarchical relationship, enabling the 3D mesh structure to have a clear hierarchical organization, thereby supporting efficient spatial query and hierarchical transformation operations.

[0077] This application achieves regularized synchronous partitioning of longitude, latitude, and altitude in three-dimensional space through three-dimensional recursive partitioning and hierarchical relationship construction, ensuring consistency and uniformity of the grid structure across the three dimensions. Simultaneously, standardized index allocation and recursive termination control mechanisms enhance the controllability and accuracy adaptability of the spatial partitioning process. Furthermore, by combining the one-to-one correspondence between parent and child nodes, a clearly structured spatial octree system is formed, significantly improving the organization efficiency and hierarchical management capabilities of three-dimensional spatial data, and supporting efficient spatial positioning and multi-level query operations.

[0078] In one possible implementation of the embodiments of this application, combined with Figure 2 ,like Figure 8As shown, the above S205 can be implemented by the following S801 to S805, which are explained in detail below: S801. Traverse the discretized index values ​​of the three-dimensional grid cells in the three-dimensional grid system in the longitude, latitude and height dimensions, including the longitude index, latitude index and height index.

[0079] In one possible implementation, all target mesh cells are read from the three-dimensional mesh system constructed by S204; for each mesh cell, its integer index values ​​in the three dimensions of longitude, latitude and altitude are extracted; the index values ​​can be accumulated during the recursive partitioning process, for example, by recording the binary paths of each layer; the index values ​​in the three dimensions are used as input data for encoding processing.

[0080] Based on the above steps, this step provides standardized input for subsequent encoding processing by uniformly extracting the three-dimensional discrete index, which helps to ensure the accuracy and consistency of the encoding process.

[0081] S802. Convert the longitude index, latitude index, and altitude index into binary representation sequences of equal length.

[0082] In one possible implementation, first determine the maximum number of binary bits corresponding to the current grid level (e.g., if the level is L, then the number of bits is L); convert the longitude index, latitude index, and altitude index into binary representations respectively; if the number of binary bits in a certain dimension is insufficient, pad with zeros in the high bits to make the binary sequence lengths of the three dimensions consistent; finally, output three binary sequences of equal length.

[0083] Based on the above steps, this step unifies the binary bit width, enabling data of different dimensions to be interleaved, thereby supporting subsequent bit-by-bit fusion operations.

[0084] S803. According to the preset bit-by-bit interpolation rules, the binary representation sequences of longitude index, latitude index and altitude index are interleaved so that the binary bits of different dimensions are combined alternately to obtain the interleaved binary sequence.

[0085] Among them, the bitwise interpolation rule refers to the rule of inserting multiple binary sequences bit by bit in a fixed order, such as the cyclical insertion of "longitude, latitude, altitude".

[0086] In one possible implementation, starting from the highest bit of three equal-length binary sequences, the current bit of each dimension is extracted in a preset order (such as longitude, latitude, and altitude); the three extracted bits are then concatenated in order to form a new sequence fragment; then the operation is repeated to the next bit until all bits have been processed; finally, an interleaved binary sequence with a length three times that of the original is obtained.

[0087] Based on the above steps, this step achieves multi-dimensional information fusion by bit-by-bit interleaving, enabling a single sequence to express a three-dimensional spatial location, thereby improving the compactness and computability of the encoding.

[0088] S804. The interleaved binary sequences are concatenated to obtain the Morton code sequence; the Morton code sequence is used to represent three-dimensional spatial position.

[0089] In one possible implementation, the interleaved binary sequence is directly used as the encoding body; depending on the system requirements, the binary sequence can be converted into decimal integers or strings for storage; at the same time, the sequence is uniquely bound to a grid cell to identify its position in three-dimensional space; finally, the Morton coded sequence is output as a spatial index.

[0090] It should be noted that overflow issues should be avoided during the encoding conversion process, and long integers or strings should be used for storage when necessary.

[0091] S805. Combine the Morton coding sequence with the corresponding hierarchical identifier to obtain the mesh code of the three-dimensional mesh unit.

[0092] In one possible implementation, the level number of the current grid cell is obtained; the level number is combined with the Morton coding sequence according to a preset format; a final unique grid code is generated; and the code is stored in an index structure for subsequent querying, positioning, and data association.

[0093] Based on the above steps, this step integrates hierarchical information and spatial coding to achieve unique identification and multi-level expression of grid cells, which facilitates efficient spatial indexing and hierarchical management.

[0094] The coding design of this application fully adapts to the core principles of the standard TileID, supports integer index and latitude / longitude encoding / decoding adaptation, overcomes the defects of fixed coding structures in existing technologies, and has good scalability. It can flexibly adjust coding parameters and hierarchical precision according to the needs of different low-altitude economic application scenarios (such as airspace management, flight route planning, and emergency rescue). Simultaneously, it supports cross-platform data sharing and is compatible with mainstream Geographic Information Systems (GIS), UAV control systems, and other platforms, solving the problems of insufficient adaptability and difficulty in cross-platform sharing in existing technologies, and improving data reuse rate. By clearly defining the parent-child hierarchical mapping relationship, this application simplifies the mapping calculation process for the conversion from coarse-grained grids to fine-grained grids. Calculations can be performed using integer index mapping relationships, improving cross-level operation efficiency by more than 50% compared to existing technologies. It also achieves highly efficient multi-level composite retrieval of raster data. In multi-level data retrieval tests, the retrieval accuracy reached over 99.8%, and the retrieval speed was improved by 60% compared to existing technologies, enabling rapid response to multi-level data retrieval needs "from large-scale to precise units" in low-altitude economic scenarios.

[0095] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, disclosure, and appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple instances. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0096] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely exemplary illustrations of this application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the spirit and scope of this application. Thus, if such modifications and modifications of this application fall within the scope of the claims of this application and their equivalents, this application is also intended to include such modifications and modifications.

Claims

1. A three-dimensional extended global mesh generation method based on a spatial octree, characterized in that, include: The Earth's latitude and longitude space is pre-divided into hemispherical segments to construct a basic space with consistent latitude and longitude spans; Based on the aforementioned basic space, a recursive partitioning is performed along the longitude and latitude dimensions to construct a multi-level grid structure; Based on the multi-level grid structure, the height domain is extended and mapped to construct a three-dimensional unified spatial expression system of longitude, latitude and height. Based on the three-dimensional unified spatial representation system of longitude, latitude and altitude, the three-dimensional spatial units are synchronously bisected and recursively partitioned to construct a three-dimensional mesh system adapted to the spatial octree structure. Based on the aforementioned three-dimensional grid system, a bitwise interpolation encoding method is used to fuse and encode the longitude, latitude, and altitude indices to obtain the grid code of the three-dimensional grid unit; the grid code of the three-dimensional grid unit includes a hierarchy identifier; Based on the mesh encoding of the three-dimensional mesh unit, a parent-child mapping relationship is established between meshes of different levels to obtain the global mesh subdivision result.

2. The method according to claim 1, characterized in that, The process of pre-dividing the Earth's latitude and longitude space into hemispherical segments to construct a basic space with consistent latitude and longitude spans includes: The Earth's latitude and longitude space is pre-divided into hemispherical segments, dividing the longitude range into western and eastern hemisphere intervals, so that the longitude span of a single hemisphere is consistent with the latitude span, thus constructing a basic space with consistent latitude and longitude spans.

3. The method according to claim 1, characterized in that, Based on the aforementioned basic space, a multi-level grid structure is constructed by recursively partitioning the space along the longitude and latitude dimensions, including: Based on the basic space, a bisection method is used to recursively partition the data in the longitude and latitude dimensions to construct a multi-level grid. The grid sizes of adjacent levels of the multi-level grid are kept at a ratio of two, forming a multi-level two-dimensional grid structure with a clear parent-child hierarchical mapping relationship.

4. The method according to claim 1, characterized in that, The process of extending and mapping the height domain based on the multi-level grid structure to construct a unified three-dimensional spatial representation system of longitude, latitude, and altitude includes: Based on a multi-level grid structure, the height dimension is mapped to the first interval according to a preset ratio, so that the physical size of the height dimension is consistent with the physical size of the latitude direction, thus constructing a three-dimensional unified spatial expression system of longitude, latitude and height.

5. The method according to claim 4, characterized in that, The first interval ranges from 0 degrees to 90 degrees.

6. The method according to claim 1, characterized in that, The aforementioned three-dimensional unified spatial representation system based on longitude, latitude, and altitude performs synchronous binary recursive partitioning of three-dimensional spatial units to construct a three-dimensional mesh system adapted to a spatial octree structure, including: The initial grid unit is a three-dimensional spatial unit composed of longitude, latitude, and altitude. In each recursive level, the current grid cell is synchronously bisected along the longitude, latitude, and altitude dimensions, dividing the current grid cell into eight sub-grid cells. Assign a corresponding three-dimensional spatial index position to each sub-mesh cell to identify the relative spatial orientation of each sub-mesh cell in the parent mesh cell; Repeatedly perform the binary recursive partitioning operation on the sub-mesh unit until the preset level depth or target spatial resolution requirement is reached; During the recursive subdivision operation, a one-to-one correspondence between parent and child mesh units is established step by step according to the subdivision level, resulting in a hierarchical three-dimensional mesh system that satisfies the spatial octree structure.

7. The method according to claim 1, characterized in that, Based on the aforementioned three-dimensional grid system, a bitwise interpolation encoding method is used to fuse and encode the longitude, latitude, and altitude indices to obtain the grid code of the three-dimensional grid cell, including: Traverse the discretized index values ​​of the three-dimensional mesh cells in the three-dimensional mesh system in the longitude, latitude and height dimensions, including the longitude index, latitude index and height index; The longitude index, latitude index, and altitude index are each converted into a binary representation sequence of equal length. According to the preset bit-by-bit interpolation rules, the binary representation sequences of the longitude index, latitude index and altitude index are interleaved, so that the binary bits of different dimensions are combined alternately to obtain the interleaved binary sequence. The interleaved binary sequences are concatenated to obtain the Morton coding sequence; the Morton coding sequence is used to represent three-dimensional spatial position. The Morton coding sequence is combined with the corresponding hierarchical identifier to obtain the mesh code of the three-dimensional mesh cell.

8. The method according to claim 1, characterized in that, After obtaining the global grid partitioning results, the method further includes calculating the physical dimensions of the three-dimensional grid cells based on latitude information, including: Obtain the latitude value and Earth radius parameter corresponding to the target 3D mesh cell; Calculate the length of the equatorial latitude based on the Earth's radius parameters; Calculate the length of the parallel at the target latitude based on the latitude value; Based on the longitude and latitude span of the current grid level, the latitude length is mapped to the grid angle span to obtain the actual physical size of the grid cell in the longitude and latitude directions; Based on the physical dimensions in the longitude and latitude directions, the spatial physical scale information of the three-dimensional grid cells is determined.

9. A three-dimensional extended global mesh partitioning system based on a spatial octree, characterized in that, The system includes: a hemispherical pre-partitioning module, a two-dimensional recursive partitioning module, a height domain mapping module, a three-dimensional mesh construction module, an encoding generation module, and a hierarchical mapping module; The hemispherical pre-segmentation module is used to perform hemispherical pre-segmentation processing on the Earth's latitude and longitude space to construct a basic space with consistent latitude and longitude spans. The two-dimensional recursive partitioning module is used to perform recursive partitioning based on the base space in the longitude and latitude dimensions to construct a multi-level grid structure. The height domain mapping module is used to perform extended mapping processing on the height domain based on the multi-level grid structure, and to construct a three-dimensional unified spatial expression system of longitude, latitude and height. The three-dimensional mesh construction module is used to perform synchronous binary recursive subdivision of three-dimensional spatial units based on the three-dimensional unified spatial expression system of longitude, latitude and altitude, and construct a three-dimensional mesh system adapted to the spatial octree structure. The encoding generation module is used to fuse the longitude, latitude, and altitude indices using a bitwise interpolation encoding method based on the three-dimensional grid system to obtain the grid code of the three-dimensional grid unit; the grid code of the three-dimensional grid unit includes a hierarchical identifier; The hierarchical mapping module is used to establish parent-child mapping relationships between different levels of meshes based on the mesh encoding of the three-dimensional mesh unit, so as to obtain the global mesh subdivision result.

10. The system according to claim 9, characterized in that, The hemispherical pre-segmentation module is also used to: perform hemispherical pre-segmentation processing on the Earth's latitude and longitude space, divide the longitude range into the western hemisphere interval and the eastern hemisphere interval, so that the longitude span of a single hemisphere is consistent with the span of the latitude range, and construct a basic space with consistent longitude and latitude span.

Images