CN108830929A - Multi-resolution Terrain pyramid model generation method and system based on database - Google Patents
Multi-resolution Terrain pyramid model generation method and system based on database Download PDFInfo
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Abstract
The invention discloses a kind of multi-resolution Terrain pyramid model generation method and system based on database, pass through these three steps of data acquisition-model generation-data loading, existing pyramid model method is significantly improved, greatly reduce the time and I/O number that data search positions, so that data can be shared, color applying drawing speed is improved；Model data can be reduced the amount of redundancy of data, reduce data prediction and storage time, improve roaming response speed according in preset rules deposit database simultaneously.
Description
Technical Field
The invention relates to the field of three-dimensional GIS, in particular to a multi-resolution terrain pyramid model generation method and system based on a database.
Background
Three-dimensional terrain visualization is an application technology relating to three subject fields of computer graphics, multimedia science and geographic information science, and is a process of performing multi-resolution organization, modeling and rendering on terrain data in a certain area range. At present, large-scale three-dimensional terrain visualization technology is widely applied in various fields. Such as military simulation combat systems, 3D gaming, street view navigation, city planning, etc.
With the continuous development of computer graphics, computer graphics hardware technology and computer storage hardware level, computer simulation and visualization technology is mature day by day, which also provides new power for the deep development of three-dimensional terrain visualization technology. However, even for large-scale topographic data with data volume as much as GB or even TB, both on the organization and storage of the data and on the computational scheduling of the data, the real-time rendering of the three-dimensional topographic data is greatly challenged.
In the prior art, a method for constructing a multi-resolution terrain pyramid model starts from DEM (Digital elevation model) data, but does not consider the capability of a computer rendering device, and has hard requirements on the width and height of original data, that is, the width and height must be 2 N ×2 N However, the actual original data width and height size of a certain region cannot just meet the requirement. Meanwhile, the storage mode of the topographic data is mainly based on files or folders, a plurality of files or folders need to be established in the mode, the data organization structure is not compact, the index numbering is complicated, the data updating is slow, and multi-user operation under a network environment is not supported.
Therefore, by combining the rapid development of the current three-dimensional terrain visualization and based on the current state of China, an operable, economic and effective method is designed, and the method has great significance for the development of the three-dimensional GIS field.
Disclosure of Invention
The invention provides a multi-resolution terrain pyramid model generation method and a multi-resolution terrain pyramid model generation system based on a database aiming at the challenge brought by the real-time rendering of the current three-dimensional terrain by the high storage of big data in the prior art, and the existing pyramid model method is greatly improved by three steps of data acquisition, model generation and data storage, so that the time and I/O times of data searching and positioning are greatly reduced, the data can be shared, and the rendering and drawing speed is improved; meanwhile, the model data is stored in the database according to the preset rule, so that the redundancy of the data can be reduced, the data preprocessing and storage time is reduced, and the roaming response speed is improved.
In order to achieve the purpose, the invention adopts the technical scheme that: the multi-resolution terrain pyramid model generation method based on the database comprises the following steps:
s1, acquiring original terrain data and performing format conversion to acquire DEM data and DOM data;
s2, respectively generating a multi-resolution DEM pyramid model and a multi-resolution DOM pyramid model by utilizing the DEM data and the DOM data acquired in the S1 according to the video memory limitation;
and S3, storing the data of the multi-resolution DEM pyramid model and the data of the multi-resolution DOM pyramid model into a database according to a preset rule.
As a modification of the present invention, the step S2 includes:
s21, reading DEM data and DOM data;
s22, determining the model layer number of the multi-resolution DEM pyramid model and the multi-resolution DOM pyramid model according to the DEM data and the DOM data acquired in the S21;
s23, respectively determining the terrain block size of the DEM data and the DOM data according to the model layer number and the video memory limit;
s24, invalid data filling processing is carried out on the DEM data and the DOM data;
s25, partitioning the DEM data and the DOM data subjected to the filling processing of the invalid data S24 according to the size of the terrain partition in the S23;
s26, calculating the roughness value of each DEM block;
s27, resampling the partitioned DEM data and DOM data by a bilinear interpolation method to generate previous-layer data;
s28, repeating steps S25 to S27 until reaching the model level of the multi-resolution DEM pyramid model and the multi-resolution DOM pyramid model in S22.
As an improvement of the present invention, in step S22, the number k of DEM blocks included in the DOM data is calculated according to the following formula:
k=max(RasterXSize，RasterYSize)/(max(col，row)-1);
wherein max (RasterXSize, RasterYSize) is the larger of both the DOM data width and height, and max (col, row) is the larger of both the rows and columns in DEM data;
calculating the model layer number n of the multi-resolution DEM pyramid model and the multi-resolution DOM pyramid model according to the following formula:
k×2n∈[512，1024]and calculating the minimum positive integer n.
As another improvement of the present invention, in step S23, the DEM partition size is calculated according to the following formula:
(2n+1)×(2n+1)；
according to the optimal size of a single image supported by video memory, calculating the DOM block size by using the following formula:
max(RasterXSize，RasterYSize)/(max(col，row)-1)×2n
wherein max (RasterXSize, RasterYSize) is the larger value of the width and height of the DOM data, max (col, row) is the larger value of the rows and columns in the DEM data, and n is the number of model layers of the multi-resolution DEM pyramid model and the multi-resolution DOM pyramid model.
As another improvement of the present invention, the step S24 includes: and taking the upper left corner of the original topographic data as an origin, and performing invalid data filling processing on the original topographic data to ensure that the rows and columns of the DEM data are both 2N+1, the width and height of the DOM data are 2NWherein N is the data after fillingA smallest positive integer surrounding the raw terrain data.
As another improvement of the present invention, in step S26, a terrain roughness value is calculated in advance and stored in a database, and the roughness value of each DEM partition is calculated according to the following formula:
wherein d is the side length of the DEM block,e 1~e 6for 6 vertex error values for a terrain block node,e 7~e 10is the 4 child node error values for the terrain block node.
As another improvement of the present invention, in step S27, resampling every 2 × 2 data blocks is performed on the original topographic data subjected to the invalid data padding processing and partitioned, and if every 2 × 2 data blocks include both the original topographic data and the invalid padding data, changing the invalid padding data into a value of 0, and then performing resampling calculation; if only invalid padding data is included in every 2 x 2 data blocks, no resampling calculation is performed.
As a further improvement of the present invention, the step S3 includes:
s31, calculating the index number of each DEM block in the multi-resolution DEM pyramid model and the index number of each DOM block in the multi-resolution DOM pyramid model according to the coordinates of the terrain blocks and the number of layers of the terrain blocks in the pyramid model, and taking the index numbers as main key indexes;
s32, creating an item in the database, and creating a multi-resolution DEM pyramid model data table and a multi-resolution DOM pyramid model data table in the item;
and S33, respectively storing the data of the multi-resolution DEM pyramid model and the data of the multi-resolution DOM pyramid model into a multi-resolution DEM pyramid model data table and a multi-resolution DOM pyramid model data table in a binary BLOB mode.
As a further improvement of the present invention, in step S33, the boundary data of each DEM partition is repeatedly stored in the multi-resolution DEM pyramid model data table, and a row of records is added to the multi-resolution DOM pyramid model data table for storing the original size information and the partition size information of the DOM data.
In order to achieve the above purpose, the invention also adopts a technical scheme that: a multi-resolution terrain pyramid model generation system based on a database comprises:
a data acquisition module: acquiring original topographic data and performing format conversion to obtain DEM data and DOM data;
a model generation module: respectively generating a multi-resolution DEM pyramid model and a multi-resolution DOM pyramid model by utilizing DEM data and DOM data obtained in the data acquisition module according to the display memory limit;
a data storage module: and storing the data of the multi-resolution DEM pyramid model and the data of the multi-resolution DOM pyramid model into a database according to a preset rule.
Compared with the prior art, the invention has the beneficial effects that: the invention abandons the traditional file storage mode and adopts the storage mode of the database, thereby greatly reducing the time and the I/O times of data searching and positioning and enabling the data to be shared; the model is established by considering the display performance of the video memory, so that the performance of computer hardware can be fully utilized, and the rendering and drawing speed is improved; the model data is stored in the database according to the preset rule, so that the redundancy of the data can be reduced, the data preprocessing and storage time is reduced, and the roaming response speed is improved.
Drawings
Fig. 1 is a flowchart of a database-based multi-resolution terrain pyramid model generation method according to an embodiment of the present invention;
FIG. 2 is a schematic diagram illustrating determination of terrain roughness in an embodiment of the present invention;
FIG. 3 is a schematic diagram illustrating DEM boundary data storage principles in an embodiment of the present invention;
fig. 4 is a block diagram of a database-based multi-resolution terrain pyramid model generation system according to an embodiment of the present invention.
Detailed Description
The invention will be explained in more detail below with reference to the drawings and examples.
Example 1
A method for generating a multi-resolution terrain pyramid model based on a database, as shown in fig. 1, includes the following steps:
s1, acquiring original terrain data and performing format conversion to acquire DEM data and DOM data; original terrain data needing three-dimensional visualization operation can be downloaded from LocalSpaceViewer, and a downloaded terrain elevation data File in a TIFF (Tag Image File Format) Format is converted into regular grid DEM data by using a [ Rate to ASCII ] function of an ArcToolbox conversion tool in ArcMap software; DOM (digital ortho image) data is downloaded with TIFF format unchanged.
It should be noted that the DEM data of the regular grid is generally a text file with asc as suffix, which contains 6 rows of header information and several rows of elevation data values. In the header information, ncols and nrows respectively represent the column number and the row number of the terrain data of the regular grid, xllcorner and ylcerner represent the coordinates of the corner point at the lower left corner of the grid, cellsize refers to the size of a pixel, namely the size of each grid unit, NODATA _ value represents invalid data, and the rest is elevation data of corresponding coordinates.
S2, respectively generating a multi-resolution DEM pyramid model and a multi-resolution DOM pyramid model by utilizing the DEM data and the DOM data acquired in the S1 according to the video memory limitation;
and S3, storing the data of the multi-resolution DEM pyramid model and the data of the multi-resolution DOM pyramid model into a database according to a preset rule, wherein an Oracle database can be selected, and the data of the multi-resolution DEM pyramid model and the data of the multi-resolution DOM pyramid model are stored into the Oracle database according to the preset rule, so that the method is convenient and fast.
Example 2
The present embodiment is different from embodiment 1 in that: step S2 includes:
s21, reading DEM data and DOM data, such as DEM data row and column number, DOM image size, etc. For regular grid DEM data, the larger of both the rows and columns in the DEM data is obtainedmax(col，row). For DOM Data, the larger value of the DOM Data width and the DOM Data height is obtained by means of a GDAL (spatial Data transformation Library) functionmax(RasterXSize，RasterYSize)。
S22, determining the model layer number of the multi-resolution DEM pyramid model and the multi-resolution DOM pyramid model according to the DEM data and the DOM data acquired in the S21; by the formulak=max(RasterXSize，RasterYSize)/(max(col，row)-1)And calculating the number of DEM blocks contained in the DOM data. Based on the optimum size of single image supported by video memory, i.e. conditionsk×2 n ∈[512，1024]Calculating the minimum positive integernObtaining the multi-resolution pyramid layer numbern。
S23, determining the terrain block size of the DEM data and the DOM data according to the model layer number and the video memory limit, and calculating the DEM block size according to the following formula;
(2n+1)×(2n+1)；
calculating the DOM block size by using the following formula according to the optimal single image size supported by the video memory;
max(RasterXSize，RasterYSize)/(max(col，row)-1)×2n。
the method is characterized in that the sizes of the DEM blocks and the DOM blocks are calculated from the corresponding relation between the optimal single image size supported by the video memory and the DEM and DOM data range, so that the performance of computer hardware can be fully considered for original terrain data of any size, the rendering and drawing performance of the video memory can be fully exerted, the rendering and drawing are smooth, and if the optimal single image range supported by the video memory changes, the defined constant value only needs to be modified in a program. Meanwhile, the layer number of the pyramid model does not need to be set in advance in a program, and the size of the topmost layer data in the gold model data does not need to be limited. The calculation method can freely control the hierarchical layer number of the pyramid and the size of the topmost pyramid model data (not necessarily 2)n×2n）。
And S24, performing invalid data filling processing on the DEM data and the DOM data, and if the invalid data filling processing is not performed, performing blocking operation on boundary data, and if the size of the boundary data does not meet the size requirement of each block, calculating the number of rows and columns of data and the positions of the data of the blocks which do not meet the requirement, so that the processing of terrain blocking is not facilitated. In this embodiment, the process of terrain blocking can be accelerated by performing invalid data filling on the original data, and repeated calculation at the boundary can be avoided.
And taking the upper left corner of the original topographic data as an origin, and performing invalid data filling processing on the original topographic data to ensure that the rows and columns of the DEM data are both 2N+1, the width and height of the DOM data are 2NAnd N is the minimum positive integer which can enable the filled data to just surround the original terrain data.
This defines invalid data-9999 to perform invalid data filling processing on the original topographic data to make the size meet the requirement.
S25, partitioning the DEM data and the DOM data subjected to the filling processing of the invalid data S24 according to the size of the terrain partition in the S23;
s26, calculating the roughness value of each DEM block; the roughness data of the terrain data is calculated in advance, so that the time consumption for determining the terrain data hierarchy required in the data scheduling process and the time consumption for calculating the terrain subdivision degree in the terrain triangulation network drawing can be reduced.
As shown in fig. 2, the roughness value of each DEM partition can be calculated according to the following formula;
wherein d is the side length of the DEM block,e 1~e 6for 6 vertex error values for a terrain block node,e 7~e 10is the 4 child node error values for the terrain block node.
S27, resampling the partitioned DEM data and DOM data by a bilinear interpolation method to generate previous-layer data;
the conventional generation method of the terrain pyramid is as follows: DEM data are sampled in an interlaced and spaced mode, and DOM data are sampled by a three-time convolution method. In the method, due to the fact that the DEM data and the DOM data are different in sampling mode, when texture mapping operation is carried out in the terrain visualization process, image textures (DOM) stretch, the terrain visualization effect quality is low, and the simulation effect is not real. Meanwhile, the triple convolution method has the advantages of high precision and edge enhancement, but has the defects of large calculation amount, low speed and excessive time consumption for sampling large-scale shape data by using the method. In the embodiment, the bilinear interpolation method is adopted for resampling, the precision and the calculated amount are moderate, the low-pass filtering effect is achieved, the edge of the resampled image is smooth, and the average filtering effect is achieved. The DEM data and the DOM data both use a bilinear interpolation method, so that the data change rules are consistent, and the texture stretching phenomenon cannot occur during texture mapping operation.
The resampling process in this step also involves redefining invalid data at the edges of the original topographic data: resampling every 2 x 2 data blocks of the original topographic data subjected to invalid data filling processing and partitioned, and if every 2 x 2 data blocks comprise both the original topographic data and invalid filling data, changing the invalid filling data into a numerical value of 0, and then performing resampling calculation; if only invalid padding data is included in every 2 x 2 data blocks, no resampling calculation is performed.
Therefore, the invalid data value is not directly defined as 0, but is firstly defined as-9999 and then modified to 0, so that the problem that the range of the original terrain cannot be accurately determined under the condition that a large number of 0 values exist in the terrain edge data is avoided, and excessive redundant data are increased.
S28, repeating steps S25 to S27 until reaching the model level of the multi-resolution DEM pyramid model and the multi-resolution DOM pyramid model in S22.
Example 3
The present embodiment is different from embodiment 1 in that: step S3 further includes:
s31, calculating the index number of each DEM block in the multi-resolution DEM pyramid model and the index number of each DOM block data in the multi-resolution DOM pyramid model according to the coordinates of the terrain blocks and the number of layers of the terrain blocks in the pyramid model, and taking the index numbers as main key indexes;
according to formula ID=ix*total_row+iy*total*col+levCalculating the index number of each DEM block data and DOM block data in the multi-resolution pyramid model; wherein,ix、iyis the horizontal and vertical of the current terrain blockThe coordinates of the position of the object to be imaged,total_row、total_colrespectively the number of rows and columns of the whole original data,levthe resolution level of the current terrain block.
In this embodiment, the acquisition of the number fully uses all information of the data. Therefore, under the condition that the number and the row and column numbers of the terrain blocks are known, the layer numbers of the terrain blocks in the pyramid model can be calculated. For example, for different layer data with the same row and column positions, the layer number can be known according to the number value.
S32, creating an item in a database, and creating a multi-resolution DEM pyramid model data table and a multi-resolution DOM pyramid model data table in the item;
in this embodiment, an Oracle database is used, an item is created in the database, and a multi-resolution DEM pyramid model data table and a multi-resolution DOM pyramid model data table are created in the item. The obtained data of the multi-resolution DEM pyramid model and the data of the multi-resolution DOM pyramid model are stored in an search database according to a certain rule, and the number of the ground block is set as the index of the main key, so that the redundancy of the data can be reduced, the time for preprocessing and storing the data is shortened, and the response speed of the scene during roaming is improved.
And S33, respectively storing the data of the multi-resolution DEM pyramid model and the data of the multi-resolution DOM pyramid model into a multi-resolution DEM pyramid model data table and a multi-resolution DOM pyramid model data table in a binary BLOB mode.
In this embodiment, the table named GEO _ DATA (i.e., the multi-resolution DEM pyramid model DATA table) is used for storing the multi-resolution DEM pyramid model DATA, and the column names GEO _ ID, LEV, GEO, NORMAL are used for storing the index ID, hierarchical level, and hierarchical level of the DEM pyramid model DATA, respectivelylevElevation and terrain roughness values; meanwhile, for DEM data, since the data amount thereof is much smaller than that of the DOM, the boundary data for each DEM partition is repeatedly stored in the database, as shown in fig. 3.
A table named TIFF _ DATA (i.e., a multi-resolution DOM pyramid model DATA table) for storing multi-resolution DOM pyramid model DATA, column names TIFF _ ID, LEV, TIFF for storing index ID, hierarchy level, respectively, of DOM pyramid model DATAlevThe image RGB value; meanwhile, a row of records is added in the table for storing original size information and block size information of the DOM data.
Model data are respectively stored into a multi-resolution DEM pyramid model data table and a multi-resolution DOM pyramid model data table in a binary BLOB mode by using an ORacle database OCI (Oracle Call Interface, Oracle Interface Call), so that the data access process can be accelerated.
In the data warehousing process, for DEM data, the data volume is far smaller than that of DOM data, so that the boundary data of each DEM block is repeatedly stored in the database. For DOM data, the data format is TIFF, and although the file in the format has high image quality, the file has low compression rate and occupies a large amount of memory. In order to avoid storing a large amount of invalid data, a row of records is added in a table for storing multi-resolution DOM pyramid model data, and the records are used for storing original size information and block size information of the DOM data, so that a program can calculate outline information of the boundary data according to information of a previous column or a previous row when the DOM boundary data is scheduled subsequently.
Example 4
The multi-resolution terrain pyramid model generation system based on the database comprises a data acquisition module, a model generation module and a data library module.
The data acquisition module is used for acquiring original topographic data and performing format conversion to acquire DEM data and DOM data; the model generation module is used for respectively generating a multi-resolution DEM pyramid model and a multi-resolution DOM pyramid model by utilizing the DEM data and the DOM data according to the display memory limit; and the data storage module stores the data of the multi-resolution DEM pyramid model and the data of the multi-resolution DOM pyramid model into a database according to a preset rule.
In the above embodiment, the technical problems of narrow applicability, large data redundancy and long data searching and positioning time in the existing method are solved. The storage mode of the database is adopted, so that the time for searching and positioning data and the I/O times can be greatly reduced, and the data can be shared; the model is established by considering the display performance of the video memory, can be suitable for terrain data in any size range, fully utilizes the performance of computer hardware and improves the rendering and drawing speed; the model data is stored in the database according to the preset rule, so that the redundancy of the data can be reduced, the data preprocessing and storage time is reduced, and the roaming response speed is improved.
The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited by the foregoing examples, which are provided to illustrate the principles of the invention, and that various changes and modifications may be made without departing from the spirit and scope of the invention, which is also intended to be covered by the appended claims. The scope of the invention is defined by the appended claims and equivalents thereof.
Claims (10)
1. The multi-resolution terrain pyramid model generation method based on the database is characterized by comprising the following steps of:
s1, acquiring original terrain data and performing format conversion to acquire DEM data and DOM data;
s2, respectively generating a multi-resolution DEM pyramid model and a multi-resolution DOM pyramid model by utilizing the DEM data and the DOM data acquired in the S1 according to the video memory limitation;
and S3, storing the data of the multi-resolution DEM pyramid model and the data of the multi-resolution DOM pyramid model into a database according to a preset rule.
2. The database-based multi-resolution terrain pyramid model generation method of claim 1, wherein the step S2 includes:
s21, reading DEM data and DOM data;
s22, determining the model layer number of the multi-resolution DEM pyramid model and the multi-resolution DOM pyramid model according to the DEM data and the DOM data acquired in the S21;
s23, respectively determining the terrain block size of the DEM data and the DOM data according to the model layer number and the video memory limit;
s24, invalid data filling processing is carried out on the DEM data and the DOM data;
s25, partitioning the DEM data and the DOM data subjected to the filling processing of the invalid data S24 according to the size of the terrain partition in the S23;
s26, calculating the roughness value of each DEM block;
s27, resampling the partitioned DEM data and DOM data by a bilinear interpolation method to generate previous-layer data;
s28, repeating steps S25 to S27 until reaching the model level of the multi-resolution DEM pyramid model and the multi-resolution DOM pyramid model in S22.
3. The database-based multi-resolution terrain pyramid model generation method according to claim 2, wherein in step S22, the number k of DEM blocks included in DOM data is calculated according to the following formula:
k=max(RasterXSize，RasterYSize)/(max(col，row)-1);
wherein max (RasterXSize, RasterYSize) is the larger of both the DOM data width and height, and max (col, row) is the larger of both the rows and columns in DEM data;
calculating the model layer number n of the multi-resolution DEM pyramid model and the multi-resolution DOM pyramid model according to the following formula:
k×2n∈[512，1024]meter for measuringThe smallest positive integer n is calculated.
4. The database-based multi-resolution terrain pyramid model generation method of claim 2, wherein in step S23, the DEM partition size is calculated according to the following formula:
(2n+1)×(2n+1)；
according to the optimal size of a single image supported by video memory, calculating the DOM block size by using the following formula:
max(RasterXSize，RasterYSize)/(max(col，row)-1)×2n
wherein max (RasterXSize, RasterYSize) is the larger value of the width and height of the DOM data, max (col, row) is the larger value of the rows and columns in the DEM data, and n is the number of model layers of the multi-resolution DEM pyramid model and the multi-resolution DOM pyramid model.
5. The database-based multi-resolution terrain pyramid model generation method of claim 2, wherein the step S24 includes: and taking the upper left corner of the original topographic data as an origin, and performing invalid data filling processing on the original topographic data to ensure that the rows and columns of the DEM data are both 2N+1, the width and height of the DOM data are 2NAnd N is the minimum positive integer which can enable the filled data to just surround the original terrain data.
6. The database-based multi-resolution terrain pyramid model generation method of claim 2, wherein in step S26, terrain roughness values are calculated in advance and stored in the database, and the roughness value of each DEM partition is calculated according to the following formula;
wherein d is the side length of the DEM block,e 1~e 6is the topographyThe 6 vertex error values for the block nodes,e 7~e 10is the 4 child node error values for the terrain block node.
7. The database-based multi-resolution terrain pyramid model generation method according to claim 2, wherein in step S27, original terrain data subjected to invalid data padding processing and blocking is re-sampled every 2 × 2 data blocks, and if every 2 × 2 data blocks include both original terrain data and invalid padding data, the invalid padding data is changed to 0, and then re-sampling calculation is performed; if only invalid padding data is included in every 2 x 2 data blocks, no resampling calculation is performed.
8. The database-based multi-resolution terrain pyramid model generation method of any one of claims 2 to 7, wherein the step S3 includes:
s31, calculating the index number of each DEM block in the multi-resolution DEM pyramid model and the index number of each DOM block in the multi-resolution DOM pyramid model according to the coordinates of the terrain blocks and the number of layers of the terrain blocks in the pyramid model, and taking the index numbers as main key indexes;
s32, creating an item in the database, and creating a multi-resolution DEM pyramid model data table and a multi-resolution DOM pyramid model data table in the item;
and S33, respectively storing the data of the multi-resolution DEM pyramid model and the data of the multi-resolution DOM pyramid model into a multi-resolution DEM pyramid model data table and a multi-resolution DOM pyramid model data table in a binary BLOB mode.
9. The database-based multi-resolution terrain pyramid model generation method of claim 8, wherein in step S33, the boundary data of each DEM partition is repeatedly stored in a multi-resolution DEM pyramid model data table, and a row of records is added in the multi-resolution DOM pyramid model data table for storing original size information and partition size information of DOM data.
10. A multi-resolution terrain pyramid model generation system based on a database is characterized by comprising:
a data acquisition module: acquiring original topographic data and performing format conversion to obtain DEM data and DOM data;
a model generation module: respectively generating a multi-resolution DEM pyramid model and a multi-resolution DOM pyramid model by utilizing DEM data and DOM data obtained in the data acquisition module according to the display memory limit;
a data storage module: and storing the data of the multi-resolution DEM pyramid model and the data of the multi-resolution DOM pyramid model into a database according to a preset rule.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110310367A (en) * | 2019-07-03 | 2019-10-08 | 武汉大势智慧科技有限公司 | Based on large scene outdoor scene three-dimensional multi-angle 2.5D image lightweight browsing method |
| CN110390710A (en) * | 2019-07-06 | 2019-10-29 | 深圳市山水原创动漫文化有限公司 | A kind of processing method of renderer agents document |
| GB2588696A (en) * | 2019-10-30 | 2021-05-05 | Daimler Ag | Method of determining cells in a multiple resolution grid |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102122395A (en) * | 2011-01-31 | 2011-07-13 | 武汉大学 | Adaptive scale DEM (digital elevation model) modeling method capable of keeping terrain features |
| CN102867331A (en) * | 2012-08-31 | 2013-01-09 | 电子科技大学 | Graphics processing unit (GPU)-orientated large-scale terrain fast drawing method |
| CN103077209A (en) * | 2012-12-28 | 2013-05-01 | 深圳先进技术研究院 | Large-scale concurrent scheduling-supported method for placing three-dimensional spatial data |
| CN103235810A (en) * | 2013-04-23 | 2013-08-07 | 国家测绘地理信息局卫星测绘应用中心 | Intelligent remote-sensing image control point data search method |
| CN105427380A (en) * | 2015-12-23 | 2016-03-23 | 昆明能讯科技有限责任公司 | Three-dimensional map data processing method based on multiple detailed layers |
| CN105719344A (en) * | 2016-01-19 | 2016-06-29 | 东南大学 | Generation method three-dimensional land utilization present situation data model |
| CN105718481A (en) * | 2014-12-05 | 2016-06-29 | 星际空间（天津）科技发展有限公司 | Massive topographic data organization and release method |
| CN107679229A (en) * | 2017-10-20 | 2018-02-09 | 东南大学 | The synthetical collection and analysis method of city three-dimensional building high-precision spatial big data |
-
2018
- 2018-05-21 CN CN201810488439.1A patent/CN108830929A/en active Pending
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102122395A (en) * | 2011-01-31 | 2011-07-13 | 武汉大学 | Adaptive scale DEM (digital elevation model) modeling method capable of keeping terrain features |
| CN102867331A (en) * | 2012-08-31 | 2013-01-09 | 电子科技大学 | Graphics processing unit (GPU)-orientated large-scale terrain fast drawing method |
| CN103077209A (en) * | 2012-12-28 | 2013-05-01 | 深圳先进技术研究院 | Large-scale concurrent scheduling-supported method for placing three-dimensional spatial data |
| CN103235810A (en) * | 2013-04-23 | 2013-08-07 | 国家测绘地理信息局卫星测绘应用中心 | Intelligent remote-sensing image control point data search method |
| CN105718481A (en) * | 2014-12-05 | 2016-06-29 | 星际空间（天津）科技发展有限公司 | Massive topographic data organization and release method |
| CN105427380A (en) * | 2015-12-23 | 2016-03-23 | 昆明能讯科技有限责任公司 | Three-dimensional map data processing method based on multiple detailed layers |
| CN105719344A (en) * | 2016-01-19 | 2016-06-29 | 东南大学 | Generation method three-dimensional land utilization present situation data model |
| CN107679229A (en) * | 2017-10-20 | 2018-02-09 | 东南大学 | The synthetical collection and analysis method of city three-dimensional building high-precision spatial big data |
Non-Patent Citations (4)
| Title |
|---|
| PETER LINDSTROM ET AL.: "Terrain Simplification Simplified:A General Framework for View-Dependent Out-of-Core Visualization", 《IEEE TRANSACTIONS ON VISUALIZATION AND COMPUTER GRAPHICS》 * |
| 田珊珊等: "大规模地形数据实时绘制的技术研究", 《控制工程》 * |
| 郭雪峰等: "一种基于视点的大规模三维地形实时渲染算法", 《太赫兹科学与电子信息学报》 * |
| 黄冬梅等: "《海洋信息技术与应用》", 30 July 2016, 上海交通大学出版社 * |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110310367A (en) * | 2019-07-03 | 2019-10-08 | 武汉大势智慧科技有限公司 | Based on large scene outdoor scene three-dimensional multi-angle 2.5D image lightweight browsing method |
| CN110390710A (en) * | 2019-07-06 | 2019-10-29 | 深圳市山水原创动漫文化有限公司 | A kind of processing method of renderer agents document |
| CN110390710B (en) * | 2019-07-06 | 2023-03-14 | 深圳市山水原创动漫文化有限公司 | Method for processing proxy file of renderer |
| GB2588696A (en) * | 2019-10-30 | 2021-05-05 | Daimler Ag | Method of determining cells in a multiple resolution grid |
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