Method for constructing a three-dimensional visual area model for mapping data

Abstract

This invention discloses a method for constructing a 3D visualization region model for surveying and mapping data, belonging to the field of 3D visualization modeling technology. The invention determines the target range and several modeling targets, sets modeling levels and matches corresponding data scales, and determines the surveying and mapping area by grouping the modeling levels from high to low. Based on the matched data scales, it acquires surveying and mapping data and completes multi-scale modeling. This invention supports the downward conversion of high-precision data through the linkage of modeling levels and data scales, avoiding the repeated collection of low-precision data for low-level targets. Simultaneously, the expanded area of ​​high-level targets can cover low-level targets, reducing the workload of separate zoning and improving data acquisition efficiency. Furthermore, the buffer zone formed by the expansion enables smooth fusion of data at different levels, eliminating "precision gaps" at boundary stitching, ensuring the overall coherence and naturalness of the 3D visualization model, and providing accurate spatial model support for scenarios such as urban planning and regional management.

Description

Technical Field

[0001] This invention belongs to the field of 3D visualization modeling technology, specifically a method for constructing 3D visualization area models for surveying data. Background Technology

[0002] In the field of 3D visualization area model construction technology, the current mainstream modeling process usually involves first defining the target area to be modeled, and then treating all modeling targets (such as buildings, roads, vegetation, water bodies, etc.) within the area indiscriminately. This process has two main limitations:

[0003] On the one hand, existing technologies do not differentiate accuracy levels based on the importance of the modeling target and the need for detailed display. They generally adopt a "single data scale acquisition" mode. Either in pursuit of overall modeling efficiency, low-precision surveying data is uniformly collected for all targets, resulting in key targets such as landmark buildings and core facilities failing to present geometric details and texture features; or in order to ensure the accuracy of key targets, high-precision data is uniformly collected for all targets, resulting in redundant surveying data for non-key targets. This not only significantly increases data acquisition costs but also reduces the efficiency of subsequent modeling and processing due to the excessive amount of data.

[0004] On the other hand, existing technologies use an "independent delineation of each target" approach when determining the surveying area, without considering the importance and spatial correlation between different targets. Each modeling target is set up with a separate rectangular or circular surveying area, and the boundaries of adjacent targets lack coordination. This leads to repeated collection of boundary data between high-importance and low-importance targets, and the lack of a transition buffer area makes it easy for "precision gaps" to occur when stitching together data of different accuracies, which seriously affects the overall coherence and spatial consistency of the 3D visualization model.

[0005] This invention provides a method for constructing a three-dimensional visualization region model for surveying and mapping data to solve the above-mentioned technical problems. Summary of the Invention

[0006] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a method for constructing a three-dimensional visualization regional model for surveying and mapping data. This method supports the downward conversion of high-precision data by linking the modeling level with the data scale, avoiding the repeated collection of low-precision data for low-level targets. At the same time, the extended area of ​​high-level targets can cover low-level targets, reducing the workload of separate zoning and improving data collection efficiency. Moreover, the buffer zone formed by the extension can achieve smooth fusion of data of different levels, eliminate the "precision discontinuity" at the boundary splicing, and ensure that the overall three-dimensional visualization model is coherent and natural, providing accurate spatial model support for scenarios such as urban planning and regional management.

[0007] To achieve the above objectives, a first aspect of the present invention provides a method for constructing a three-dimensional visualization region model for surveying data, comprising:

[0008] Determine the target area that needs to be modeled in 3D visualization, identify several modeling targets within the target area, and set the modeling level of several modeling targets;

[0009] The data scale is matched according to the modeling level of several modeling objectives, and the mapping area of ​​the corresponding modeling objective is determined according to the modeling level.

[0010] Within the survey area of ​​several modeling targets, survey data is acquired according to the matching data scale; multi-scale modeling is performed based on the survey data of several modeling targets to construct a three-dimensional visualization model.

[0011] Preferably, the mapping area corresponding to the modeling target is determined according to the modeling level, including:

[0012] Divide the modeling objectives within the target scope into several target groups;

[0013] Select target groups in descending order of modeling level, and determine the mapping area of ​​several modeling targets in the corresponding target group.

[0014] Preferably, the modeling objectives within the target range are divided into several target groups, including:

[0015] Identify the modeling levels of several modeling targets within the target area;

[0016] Modeling objectives of the same modeling level are grouped into one objective group to divide several modeling objectives into several objective groups.

[0017] Preferably, the mapping area of ​​several modeling targets in the corresponding target group is determined, including:

[0018] The modeling targets in the target group are used as baseline targets in sequence, and the modeling targets adjacent to the baseline targets are identified as auxiliary targets;

[0019] A basic area is constructed based on the benchmark target. The basic area is then expanded according to the difference in modeling levels between the auxiliary target and the benchmark target, as well as their relative positions, to obtain the mapping area.

[0020] Preferably, the base region is expanded based on the level difference between the auxiliary target and the baseline target and their relative positions, including:

[0021] Obtain the level difference between the modeling levels of the auxiliary target and the baseline target, identify the overlapping boundaries of the base regions corresponding to the auxiliary target and the baseline target, and obtain the shortest distance between each point on the non-overlapping boundary of the base region corresponding to the auxiliary target and the overlapping boundary.

[0022] The expansion range is determined based on the grade difference and the shortest distance; the base area is expanded based on the expansion range to obtain the mapping area of ​​the benchmark target.

[0023] Preferably, the expansion range is determined based on the grade difference and the shortest distance, including:

[0024] Set distance range one and distance range two based on the shortest distance; where distance range one is [0, ZJ / 4], distance range two is (ZJ / 4, ZJ / 2], and ZJ is the shortest distance;

[0025] When the absolute value of the level difference is 1, select the target distance within distance range one; when the absolute value of the level difference is 2, select the target distance within distance range two.

[0026] The base area is expanded based on the target distance to obtain the survey area.

[0027] Preferably, the mapping data is acquired according to a matching data scale, including:

[0028] Extract the data scale for the modeling objective;

[0029] Based on the data scale, a surveying method is matched to the corresponding surveying area, and surveying data of the surveying area is collected according to the matched surveying method.

[0030] Preferably, when displaying a target area in 3D visualization, a 3D visualization model at the approximate level of the target area is displayed first; and,

[0031] When the data scale corresponding to the modeling target includes the standard scale, the modeling data is obtained by preloading the mapping data through the temporary processor configured for the modeling target.

[0032] Preferably, during the data scale switching process, it is determined whether the preloaded modeling data of the modeling target meets the filling requirements of the display area;

[0033] If yes, then display the preloaded modeling data for that modeling target;

[0034] If not, then display the preloaded modeling data for the modeling target, as well as the preloaded modeling data for adjacent modeling targets at the same data scale.

[0035] Preferably, before preloading, the direct loading time of the survey data is determined; and it is determined whether the direct loading time is less than the set loading time.

[0036] Yes, it is not necessary to preload the mapping data;

[0037] No, preload the mapping data.

[0038] Compared with the prior art, the beneficial effects of the present invention are:

[0039] 1. This invention determines the target range and several modeling targets, sets modeling levels and matches corresponding data scales, and determines the surveying area by grouping the modeling levels from high to low. Based on the matched data scales, it acquires surveying data and completes multi-scale modeling. This invention supports the downward conversion of high-precision data through the linkage of modeling levels and data scales, avoiding the repeated collection of low-precision data for low-level targets. At the same time, the expanded area of ​​high-level targets can cover low-level targets, reducing the workload of separate zoning and improving data collection efficiency. Moreover, the buffer zone formed by the expansion can achieve smooth fusion of data of different levels, eliminate the "precision discontinuity" at the boundary splicing, and ensure the overall coherence and naturalness of the 3D visualization model, providing accurate spatial model support for scenarios such as urban planning and regional management.

[0040] 2. This invention configures temporary processors for modeling targets with standard scales, determines the direct loading time of surveying data before preloading, and checks whether the preloaded data meets display filling requirements during scale switching. It also encrypts sensitive information in modeling targets. This invention avoids resource waste through on-demand preloading, reduces scale switching latency from seconds to milliseconds by storing preloaded data in temporary processors, prevents gaps in the display by calling adjacent target data, and significantly optimizes the 3D visualization interactive experience. Simultaneously, the encryption of sensitive information prevents the leakage of sensitive information such as important building structures and core pipelines without affecting model display and analysis functions, improving the system's adaptability in scenarios with security requirements such as government affairs and national defense. Attached Figure Description

[0041] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0042] Figure 1 This is a flowchart illustrating the method for constructing a three-dimensional visualization region model in Embodiment 1 of the present invention.

[0043] Figure 2 This is a schematic diagram illustrating the target types modeled within the target range in Embodiment 1 of the present invention;

[0044] Figure 3 This is a schematic diagram of the basic region corresponding to the modeled target within the target range in Embodiment 1 of the present invention;

[0045] Figure 4 This is a schematic diagram illustrating the expansion of the basic target region within the target area in Embodiment 1 of the present invention;

[0046] Figure 5This is a schematic diagram of the filling effect of the modeled target in the display area in Embodiment 2 of the present invention. Detailed Implementation

[0047] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] Example 1:

[0049] Please see Figure 1 The first aspect of the present invention provides a method for constructing a three-dimensional visualization region model for surveying data, comprising:

[0050] S100: Determine the target area that needs to be modeled in 3D visualization, identify several modeling targets within the target area, and set the modeling level of several modeling targets;

[0051] S200: Match the data scale according to the modeling level of several modeling targets, and determine the mapping area of ​​the corresponding modeling targets according to the modeling level;

[0052] S300: Within the survey area of ​​several modeling targets, acquire survey data according to the matching data scale; perform multi-scale modeling based on the survey data of several modeling targets to construct a three-dimensional visualization model.

[0053] In S100, the target range and the modeling targets within the target range are first determined. At the same time, the modeling level needs to be set according to the details that the modeling targets need to display.

[0054] During modeling, first determine the target area that needs to be modeled in 3D visualization, and identify the modeling targets within the target area; match the data scale according to the modeling level of the modeling targets; collect surveying data of the corresponding data scale of each modeling target through different surveying methods, perform multi-scale modeling based on the surveying data of each modeling target, and integrate the modeling results of all modeling targets within the target area to obtain a visualization model of the target area.

[0055] The target area is simply the region where 3D modeling is required, which can be defined by coordinates. The final modeling result is a 3D visualization model of that target area. The modeling target refers to the elements within the target area that need to be displayed, such as buildings, vegetation, bare land, water bodies, and roads.

[0056] In 3D visualization modeling, different modeling targets require different effects. Some modeling targets need to display their detailed features, and their corresponding modeling level is higher, while other modeling targets only need to display their general state, and their corresponding modeling level is lower. For example, when modeling residential buildings in a community, the area where the community is located is the target range. If the detailed features of the residential buildings within the community need to be displayed, then a higher modeling level is set for them, while the vegetation within the community does not need to display too much detail, so a lower modeling level is set for it.

[0057] In S200, the data scale is matched to the modeling level of the modeling target, and this data scale is the key to subsequent collection of surveying and mapping data.

[0058] Modeling levels for modeling objectives can be categorized into three levels, with Level 1 being the highest and Level 3 the lowest. The higher the modeling level of an objective, the more data scales it corresponds to. Data scales can also be categorized into three levels: approximate scale, standard scale, and fine scale. If the modeling level of an objective is Level 1, the matched data scales are approximate, standard, and fine scales. If the modeling level is Level 2, the matched data scales are approximate and standard scales. If the modeling level is Level 3, the matched data scale is approximate. For example, when modeling residential buildings in a community, the buildings correspond to a Level 1 modeling level, which includes three data scales: approximate, standard, and fine scales. The vegetation surrounding the buildings can be modeled at Level 3, corresponding to only one approximate scale. The roads and waterways within the community can be modeled at Level 2, corresponding to both approximate and standard scales.

[0059] The general scale is primarily used for 3D modeling of unimportant targets, requiring only the representation of terrain undulations and feature outlines. It can be based on digital elevation models (DEMs) and low-resolution imagery to generate stretched models. The standard scale is primarily used for 3D modeling of generally important targets, requiring the representation of terrain undulations, feature outlines, and texture features. It can be achieved based on medium-density point clouds (point spacing 20-50cm) and high-resolution digital line maps (DLGs). The fine scale is primarily used for 3D modeling of very important targets, requiring the representation of geometric and textural details. It can be achieved based on high-density point clouds (point spacing ≤5cm) and digital orthophoto maps (DOMs).

[0060] It should be noted that the surveying methods are selected based on the data scale and specific scenario. These include integrated space-air remote sensing technologies such as satellite remote sensing, aerial photogrammetry, and airborne lidar, which are suitable for acquiring approximate and standard-scale surveying data; ground-based mobile surveying technologies such as vehicle-mounted mobile surveying systems and backpack-mounted mobile surveying systems, which are suitable for acquiring standard and fine-scale surveying data; and ground-based static surveying technologies such as terrestrial 3D laser scanning, close-range photogrammetry, and total station / GNSS static surveying, which are suitable for acquiring fine-scale surveying data. Of course, there are also technologies such as indoor laser scanning and indoor SLAM (simultaneous localization and mapping), which will not be elaborated upon here.

[0061] In S200, after matching the data scale for each modeling target, it is also necessary to determine the mapping area of ​​the modeling target and collect mapping data based on the data scale within the corresponding mapping area.

[0062] When collecting surveying and mapping data, not all surveying and mapping targets require the same surveying and mapping data. As mentioned above, some modeling targets require surveying and mapping data at multiple scales, while others only require surveying and mapping data at one scale. It is difficult to meet the data scale requirements of all modeling targets by using a single surveying and mapping method.

[0063] Furthermore, some surveying data can be converted from high-precision to low-precision data. In other words, after collecting high-precision data, various data scales of surveying data can be obtained through technical means, without the need to collect low-precision surveying data through other surveying methods. For example, a fine-scale point cloud can be simplified to a standard-scale medium-density point cloud, and a standard-scale DOM can be downscaled for approximate scales. Therefore, when collecting data for the highest-level modeling target, only its fine-scale surveying data can be collected, and surveying data for other data scales can be obtained from the fine-scale surveying data.

[0064] It should be noted that some surveying data cannot be converted from fine scale to standard scale or approximate scale through technical means. In such cases, it is necessary to collect surveying data of the corresponding scale according to the data scale of the modeling target.

[0065] Based on this, this embodiment determines the surveying area corresponding to the modeling target from high to low modeling level, and also collects surveying data of each surveying area from high to low modeling level. This can reduce the amount of surveying data collected and improve the efficiency of surveying data collection.

[0066] In S2OO, the mapping area corresponding to the modeling target is determined according to the modeling level, including:

[0067] S210: Divide the modeling objectives within the target range into several target groups;

[0068] S220: Select target groups in descending order of modeling level, and determine the mapping area of ​​several modeling targets in the corresponding target group.

[0069] During data collection, redundant collection is necessary based on the modeling purpose to ensure smooth transitions at the seams of surveying data from different scales. The modeling targets within the target area are divided into several target groups according to their modeling level. Target groups are then selected sequentially from high to low modeling level, and the surveying areas for several modeling targets within each target group are determined. Surveying data from these areas is then obtained using surveying methods.

[0070] The target groups are divided into three groups based on the modeling level, with one target group corresponding to each modeling level. Starting with the target group with the highest modeling level, the mapping area of ​​each modeling target in the target group is determined. After the mapping areas of all modeling targets in the target group with the highest modeling level have been determined, the mapping areas of each modeling target in the target group with the slightly lower modeling level are then determined.

[0071] It is worth noting that the survey area is appropriately expanded when determining the survey area. The expanded survey area may cover modeling targets with lower modeling levels. Since the data scales can be converted, the survey area for the modeling targets with lower modeling levels does not need to be determined separately. This not only reduces the workload of determining the survey area, but also improves the efficiency of survey data collection.

[0072] Grouping the modeling targets within the target area improves the efficiency of determining the surveying area. The modeling targets within the target area are divided into several target groups, including:

[0073] S211: Identify the modeling level of several modeling targets within the target area;

[0074] S212: Group modeling objectives of the same modeling level into one objective group, so as to divide several modeling objectives into several objective groups.

[0075] As an example, not a limitation, Figure 2 The outer rectangle represents the target area for 3D visualization modeling; everything within this area is a modeling target. The rectangular areas within the target area correspond to a modeling level of 1, the triangular areas to 2, and the areas outside the circles and triangles to 3. When dividing the modeling targets, the three rectangular areas are classified as target group 1, the two triangular areas as target group 2, and the remaining areas as target group 3.

[0076] After dividing the target into several groups, the target groups are selected sequentially from high to low modeling level to determine the mapping area of ​​each modeling target. In this example, target group one should be selected first, then target group two, and finally target group three. That is, the mapping areas of each modeling target in target group one are determined first, then the mapping areas of each modeling target in target group two are determined, and finally the mapping areas of each modeling target in target group three are determined. If, when determining the mapping area of ​​a modeling target, it is identified that it has already been covered by other mapping areas, then it is not necessary to determine the mapping area of ​​that modeling target again.

[0077] In a preferred embodiment, determining the mapping area of ​​several modeling targets in a corresponding target group includes:

[0078] S221: The modeling targets in the target group are used as baseline targets in sequence, and the modeling targets adjacent to the baseline targets are identified as auxiliary targets;

[0079] S222: Construct a basic region based on the benchmark target, and expand the basic region according to the difference in modeling level between the auxiliary target and the benchmark target and their relative positions to obtain the mapping area.

[0080] After selecting a target group, it is necessary to determine the mapping area of ​​each modeling target in the target group. Since the modeling targets in the same target group have the same modeling level, the modeling targets in the target group are used as reference targets in turn, and the mapping area of ​​the reference targets is determined.

[0081] If the planar area corresponding to the benchmark target is taken as the surveying area, surveying data corresponding to this area can be collected to achieve 3D modeling of the benchmark target. However, if the modeling level of the benchmark target and the adjacent modeling targets differs significantly, the surveying data of the benchmark target may be at a fine scale, while the surveying data of the adjacent modeling targets may be at a rough scale, resulting in inconsistent modeling effects at the boundary between the benchmark target and the adjacent modeling targets.

[0082] Therefore, a base area is constructed based on the benchmark target, and the base area is expanded according to the modeling level difference and relative position between it and the adjacent modeling targets to obtain the mapping area.

[0083] A base region can be constructed based on a benchmark target. The planar area occupied by the benchmark target can be directly used as the base region, and the 3D model of the benchmark target can be completed by collecting the surveying data of this base region. However, if the benchmark target is not a regular shape, this may increase the difficulty of surveying and data fusion. In this case, the base region of the benchmark target can be constructed by using preset graphics, such as rectangles, circles, or triangles. The planar area corresponding to the preset graphics containing the benchmark target is used as the base region.

[0084] As an example, not a limitation, Figure 3The circular and triangular black dots are the modeling targets. The rectangular area corresponding to the circular black dot is its base area, and the triangular area corresponding to the triangular black dot is its base area. Assuming that modeling target A is the baseline target and its adjacent modeling target B is the auxiliary target, the base area of ​​modeling target A is expanded considering the modeling level and relative position between modeling target A and modeling target B.

[0085] In a preferred embodiment, the base region is expanded based on the level difference between the auxiliary target and the baseline target and their relative positions, including:

[0086] S222-11: Obtain the level difference between the modeling levels of the auxiliary target and the baseline target, identify the overlapping boundaries of the base regions corresponding to the auxiliary target and the baseline target, and obtain the shortest distance between each point on the non-overlapping boundary of the base region corresponding to the auxiliary target and the overlapping boundary.

[0087] S222-12: Determine the expansion range based on the grade difference and the shortest distance; expand the base area based on the expansion range to obtain the mapping area of ​​the benchmark target.

[0088] The reason for expanding the base area of ​​the benchmark target is to improve the 3D modeling effect of adjacent modeling targets. However, the base area cannot be directly expanded to cover adjacent modeling targets, as this would increase the amount of survey data collected and the difficulty of data processing. Therefore, it is necessary to comprehensively consider the difference in modeling level and relative position when expanding the base area.

[0089] The expansion strategy for the base region is as follows: the greater the difference in modeling level between the baseline target and the auxiliary target, and the greater the shortest distance, the larger the expansion of the base region, but it will not directly cover the auxiliary target. The expanded region can serve as a buffer area for data fusion, where data fusion can be performed to ensure a smooth transition in modeling effects.

[0090] As an example, not a limitation, with Figure 3 Taking modeling target A and modeling target B as examples, as mentioned above, modeling target A has a modeling level of 1, and modeling target B has a modeling level of 2, so their modeling levels differ by 1 level. Modeling target B is on one side of modeling target A, and the lower boundary of modeling target B overlaps with the upper boundary of modeling target A, forming an overlapping boundary; the other two sides of the base region corresponding to modeling target B are non-overlapping boundaries, and the dashed lines inside the triangular region correspond to the shortest distance between some points on the non-overlapping boundaries and the overlapping boundaries. In a preferred embodiment, the expansion range is determined based on the level difference and the shortest distance, including:

[0091] S222-21: Set distance range one and distance range two according to the shortest distance; where distance range one is [0, ZJ / 4], distance range two is (ZJ / 4, ZJ / 2], and ZJ is the shortest distance;

[0092] S222-22: When the absolute value of the grade difference is 1, select the target distance within distance range one; when the absolute value of the grade difference is 2, select the target distance within distance range two.

[0093] S222-23: The base area is expanded based on the target distance to obtain the survey area.

[0094] As an example, not a limitation, Figure 4 The closed area between the dashed arc and the overlapping boundary within the triangular region corresponds to distance range one, while the closed area between the dashed arc and the solid arc corresponds to distance range two. In other words, if modeling target A and modeling target B are at the same modeling level, when the rectangle corresponding to modeling target A expands upwards, it can extend to the position of the solid arc at most. Referring to the previous example, if modeling target A has a modeling level of one and modeling target B has a modeling level of two, then their modeling levels differ by one level. Therefore, when the rectangle corresponding to modeling target A expands upwards, it can extend to the position of the dashed arc at most.

[0095] It should also be noted that the modeling level difference between the auxiliary target and the baseline target is 0, meaning that the auxiliary target and the baseline target have the same modeling level. In this case, the base area of ​​the baseline target does not need to be expanded in the relative direction between the two. If the baseline target has the same modeling level as all adjacent auxiliary targets, then the base area of ​​the baseline target can be used as the mapping area. Of course, the base area can also be slightly expanded to ensure that the mapping areas corresponding to modeling targets with the same modeling level overlap.

[0096] It should also be noted that when the base area corresponding to the auxiliary target adjacent to the baseline target is very large, it will result in the distance range one and distance range two obtained according to this technical solution being particularly large, which obviously does not meet the purpose of expanding the base area. In this case, reasonable distance range one and distance range two can be set directly, or the base area of ​​the baseline target can be used as a limiting standard, for example, the shortest distance from the center point of the base area to the boundary of the base area can be used to determine distance range one and distance range two.

[0097] When determining the surveying area for a modeling target, it is necessary to consider not only the target's own extent but also the modeling level of its adjacent targets. If the modeling level of an adjacent target differs from that of the target, the surveying area of ​​the target should be appropriately expanded; the greater the difference in modeling levels, the larger the surveying area should be.

[0098] In S300, mapping data is acquired according to a matching data scale, including:

[0099] Extract the data scale for the modeling objective;

[0100] Based on the data scale, a surveying method is matched to the corresponding surveying area, and surveying data of the surveying area is collected according to the matched surveying method.

[0101] Mapping data can be collected based on the highest data scale corresponding to the modeling target. The collected mapping data can then be processed into lower-scale mapping data using technical means. If the corresponding mapping data cannot be converted using existing technical means, or the conversion efficiency is low, then it is necessary to collect mapping data at various data scales of the modeling target. Mapping means refer to the tools and carriers for acquiring mapping data at the corresponding data scale, while technical means refer to the conversion tools built into various mapping data processing software.

[0102] As an example, not a limitation, Figure 4 The mapping area corresponding to modeling target A is the base area, extending upwards to the arc curve region. Since modeling target A corresponds to modeling level one, it is necessary to collect fine-scale mapping data, such as high-precision point clouds, from its corresponding mapping area. Modeling target B corresponds to modeling level two, requiring the collection of standard-scale mapping data, such as medium-precision point clouds, from its corresponding mapping area. The area within the target range, excluding the mapping areas corresponding to modeling targets A and B, corresponds to modeling level three, requiring the collection of approximate-scale mapping data from its corresponding mapping area.

[0103] In S300, multi-scale modeling is performed based on the mapping data of several modeling targets to construct a three-dimensional visualization model.

[0104] After obtaining the mapping data for several modeling targets, 3D modeling techniques are used to model each target, and modeling is performed at multiple data scales for each target. After the modeling of the targets is completed, the models corresponding to the approximate levels of all modeling targets within the target range are merged to obtain a 3D visualization model. When switching the data scale of the modeling targets, the 3D visualization model displays the modeling effects of the target at the fine scale and the standard scale.

[0105] Example 2:

[0106] During 3D visualization modeling, mapping data at all data scales of the modeling target are processed for modeling, and the 3D visualization model of the target range is completed based on the modeling results. For modeling targets with multiple data scales, a temporary processor is configured for them. When displaying the target range in 3D visualization, this temporary processor is used to preload the mapping data of the modeling target. Data interaction can be performed between the temporary processors.

[0107] During 3D visualization or preloading, sensitive information in the surveying data should be considered. The modeling targets corresponding to sensitive information should be encrypted to prevent leakage. This way, when switching between different scales, data reloading is unnecessary; the corresponding preloaded data can be displayed directly, effectively reducing interaction latency.

[0108] It should be noted that the temporary processor is mainly used to preload the survey data of the modeling target to obtain the modeling data, so that the modeling target can be quickly replaced when the data scale is switched, reducing the delay of the data scale switch. Of course, a temporary processor may not be configured for the modeling target separately, or a temporary processor may be configured for all modeling targets. This temporary processor is responsible for preloading the survey data of all modeling targets that meet the requirements and storing the modeling results, and displaying them in a timely manner when the data scale is switched.

[0109] In a preferred embodiment, when performing a 3D visualization of the target area, a 3D visualization model at the approximate level of the target area is prioritized for display; and...

[0110] When the data scale corresponding to the modeling target includes the standard scale, the modeling data is obtained by preloading the mapping data through the temporary processor configured for the modeling target.

[0111] When displaying a 3D visualization model, a rough-scale 3D visualization model of the target area is generally shown first, which can show the general outline of the target area. If further details are required, a more refined display can be achieved using pre-loaded survey data.

[0112] It should be noted that the survey data is updated in a timely manner according to the aforementioned survey area. Both the rough-level 3D visualization model and the pre-loaded detailed modeling data are generated from the updated survey data to ensure that the display effect is more in line with reality.

[0113] In a preferred embodiment, during the data scale switching process, it is determined whether the preloaded modeling data of the modeling target meets the filling requirements of the display area.

[0114] If yes, then display the preloaded modeling data for that modeling target;

[0115] If not, then display the preloaded modeling data for the modeling target, as well as the preloaded modeling data for adjacent modeling targets at the same data scale.

[0116] During the preloading process, it is necessary to consider not only the mapping data of the modeling target itself, but also the mapping data of its adjacent modeling targets. This is because if the area corresponding to the modeling target is small, it will only occupy a small part of the display area. If the data scale of most other areas is not switched, the display effect may not be natural.

[0117] As an example, not a limitation, Figure 5 The display area is an outer rectangle. Assuming that the rectangle and triangle within the display area represent the standard-scale modeling effects of two modeling targets, their display effects are obviously insufficient to effectively fill the display area, resulting in poor visualization. Therefore, standard-scale modeling data of other modeling targets that can be displayed within the display area can be loaded to ensure that the entire display area is full and improve the visualization effect of the 3D model.

[0118] In a preferred embodiment, before preloading, the direct loading time of the mapping data is determined; it is then determined whether the direct loading time is less than a set loading time.

[0119] Yes, it is not necessary to preload the mapping data;

[0120] No, preload the mapping data.

[0121] Before preloading, the need for preloading is determined based on the level of detail in the surveying data. Less detail doesn't require preloading, while more detail necessitates it to reduce interaction latency. This approach primarily considers directly loading surveying data of the required scale into the 3D visualization model. If the direct loading time is less than the set loading time, it indicates that direct loading will not affect the user experience, and preloading of that data is unnecessary; otherwise, preloading is required. Furthermore, some modeling targets initially have limited surveying data, so preloading is unnecessary and won't affect the user experience. However, as the surveying data is updated, the amount of data increases, thus requiring a preloading assessment.

[0122] The above embodiments are only used to illustrate the technical methods of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical methods of the present invention without departing from the spirit and scope of the technical methods of the present invention.

Claims

1. A method for constructing a three-dimensional visualization region model for surveying and mapping data, characterized in that, include: Determine the target area that needs to be modeled in 3D visualization, identify several modeling targets within the target area, and set the modeling level of several modeling targets; The data scale is matched according to the modeling level of several modeling targets, and the mapping area corresponding to the modeling targets is determined according to the modeling level. Within the mapping area of ​​several modeling targets, mapping data is acquired according to a matching data scale; Multi-scale modeling is performed based on the mapping data of several modeling objectives to construct a three-dimensional visualization model; Determining the mapping area corresponding to the modeling target based on the modeling level includes: The modeling objectives within the target range are divided into several target groups; Select target groups in descending order of modeling level, and determine the mapping area of ​​several modeling targets in the corresponding target group; The modeling objectives within the target range are divided into several target groups, including: Identify the modeling levels of several modeling targets within the target range; Modeling objectives of the same modeling level are grouped into one objective group to divide the modeling objectives into several objective groups; Determine the mapping areas for several modeling targets within the corresponding target group, including: The modeling targets in the target group are sequentially used as baseline targets, and the modeling targets adjacent to the baseline targets are identified as auxiliary targets; A basic region is constructed based on the benchmark target. The basic region is then expanded according to the difference in modeling levels between the auxiliary target and the benchmark target, as well as their relative positions, to obtain the mapping area. The base region is expanded based on the level difference in modeling levels between the auxiliary target and the baseline target, as well as their relative positions, including: Obtain the level difference of the modeling level between the auxiliary target and the benchmark target, identify the overlapping boundary of the base region corresponding to the auxiliary target and the benchmark target, and obtain the shortest distance between each point on the non-overlapping boundary of the base region corresponding to the auxiliary target and the overlapping boundary; The expansion range is determined based on the grade difference and the shortest distance; the base area is expanded according to the expansion range to obtain the mapping area of ​​the benchmark target; The expansion range is determined based on the grade difference and the shortest distance, including: Based on the shortest distance, distance range one and distance range two are set; where distance range one is [0, ZJ / 4], distance range two is (ZJ / 4, ZJ / 2], and ZJ is the shortest distance; When the absolute value of the grade difference is 1, the target distance is selected within the first distance range; when the absolute value of the grade difference is 2, the target distance is selected within the second distance range. The base area is expanded based on the target distance to obtain the mapping area.

2. The method for constructing a three-dimensional visualization region model for surveying data according to claim 1, characterized in that, Obtain mapping data according to the matching data scale, including: Extract the data scale of the modeling target; Based on the data scale, a surveying method is matched to the corresponding surveying area, and surveying data of the surveying area is collected according to the matched surveying method.

3. The method for constructing a three-dimensional visualization region model for surveying data according to any one of claims 1 to 2, characterized in that, When displaying a target area in 3D, prioritize showing a 3D visualization model at an approximate level of the target area; and, When the data scale corresponding to the modeling target includes the standard scale, the mapping data is preloaded for the modeling target to obtain the modeling data.

4. The method for constructing a three-dimensional visualization region model for surveying data according to claim 3, characterized in that, During the data scale switching process, it is determined whether the modeling data preloaded by the modeling target meets the filling requirements of the display area; If yes, then display the preloaded modeling data for that modeling target; If not, then display the preloaded modeling data for the modeling target, as well as the preloaded modeling data for adjacent modeling targets at the same data scale.

5. The method for constructing a three-dimensional visualization region model for surveying data according to claim 4, characterized in that, Before preloading, determine the direct loading time of the mapping data; determine whether the direct loading time is less than the set loading time. Yes, it is not necessary to preload the mapping data; No, preload the mapping data.

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