A method for optimizing the display of massive GIM models

Abstract

The present invention discloses a method for optimizing the display of a massive GIM model, comprising the following steps: constructing a coordinate system: constructing multiple coordinate systems and the relationship between different coordinate systems for different models; coordinate conversion: realizing coordinate conversion and calculating the number of layers of tile switching; drawing and displaying: drawing and displaying a GIM model diagram according to a calculation formula and a mapping relationship; pre-calling and processing: constructing tile pyramid data from the original model data for pre-calling. The present invention optimizes the GIM model, screens, groups, and transforms the models within the visible range to reduce the amount of computational data, further improves the drawing efficiency and performance, and finally performs a pre-calling method to cache the model data after the next scene transformation, which is suitable for GIM data files containing massive GIM models that need to be displayed, and quickly obtains corresponding graphic data according to the constructed tile pyramid data, thereby improving the efficiency of model display after the scene transformation.

Description

Technical Field

[0001] The present invention relates to the technical field of power transmission and transformation, and in particular to a method for optimizing and displaying massive GIM models. Background Art

[0002] At present, in the field of power transmission and transformation engineering construction, the common technical solution for 3D modeling informatization is to quickly convert the corresponding 2D drawings and symbolized finished drawings into 3D models of power transmission lines according to the connection relationship of vector graphic drawings, with high display accuracy. The model information in the GIM file data usually generates a large amount of model data. There has always been a problem of low efficiency in the data processing of massive models. When loading and displaying at the beginning, it will take a long time to load, and even when the platform is running, the computer will freeze.

[0003] For example, Chinese patent CN109783886A, published on May 21, 2019, is a system and method for integrating GIM models and IFC models. The system reads the GIM model files and IFC model files in the power grid engineering model and performs integrity checks; parses the GIM model files and IFC model files respectively, and stores the parsed results in the form of JSON or XML files; establishes mapping relationships between the description schemes of the GIM model and the IFC model and the description scheme of the unified reference model and stores them in the form of JSON or XML files after conversion; generates multiple spatial relationships by analyzing the geometric data in the unified reference model; based on multiple spatial relationships, compares the GIM conversion results and the IFC conversion results to obtain version difference results. It integrates multiple versions of IFC and GIM models of a project at multiple stages of its life cycle into the same unified reference model, providing convenience for the design and development of power grid projects and effectively saving the communication costs of engineering projects. However, it has the problem of low data processing efficiency for massive models. Summary of the invention

[0004] The technical problem to be solved by the present invention is that the current GIM model display method has the technical problem that the data processing efficiency of massive models is low, resulting in a long display loading time. A method for optimizing the display of massive GIM models is proposed, which can improve the display efficiency of models after scene change.

[0005] To achieve the above object, the technical solution adopted by the present invention is: a method for optimizing the display of massive GIM models, comprising the following steps:

[0006] S1: Construct coordinate system: Construct multiple coordinate systems and the relationship between different coordinate systems for different models;

[0007] S2: Coordinate transformation: implement coordinate transformation and calculate the number of layers for tile switching;

[0008] S3: Drawing and displaying: drawing and displaying the GIM model diagram according to the calculation formula and mapping relationship;

[0009] S4: Pre-retrieval processing: The original model data is constructed into tile pyramid data for pre-retrieval. The models within the visible range are screened, grouped, and transformed to reduce the amount of computational data and further improve rendering efficiency and performance. Finally, the pre-retrieval method is used to cache the model data after the next scene change to improve the efficiency of model display after the scene change.

[0010] Preferably, the coordinate system constructed in step S1 includes an actual model map coordinate system, a perspective model map coordinate system, a tile model map coordinate system and a visual model coordinate system.

[0011] Actual model map coordinate system: given a square range, all GIM models can be drawn within this range, and this range is called the actual model map, represented by F; perspective model map coordinate system: the actual model is projected at a given zoom level, and the rectangle formed by the projection boundary range is called the perspective model map, represented by P; tile model map coordinate system: given a tile size, represented by Tile.size, the perspective model of a given zoom level is divided into tiles, and the coordinate system that represents the perspective model with tiles as units is called the tile model map coordinate system; visual model coordinate system: the area where the computer draws the model is called the visual model map, represented by View.

[0012] Preferably, the parameters involved in the coordinate conversion process in step S2 include: actual image size, number of tiles at each level, tile size, resolution, and actual image coordinates represented by the center coordinates of the visual model image.

[0013] Among them, the actual image size, F.size represents the side length of the cube; the tile calculation formula is the pyramid model, generally using TileCount=4ZoomLevel to calculate the number of tiles at each level; tile size (Tile.size); resolution (R); the actual image coordinates ViewCenterFigure represented by the center coordinates of the visual model figure.

[0014] Preferably, the resolution is related to the actual image size, tile size and number of tiles, and the formula is R = F.size / (TileCount 1 / 2 *Tile.size)

[0015] Among them, R is the resolution; F.size is the actual image size; TileCount is the number of tiles; Tile.size is the tile size.

[0016] Resolution is the scale of the actual image. In the perspective coordinate system corresponding to a certain zoom level, the length of the actual coordinate system corresponding to one unit of length is called resolution. For example, 1:20 means that the length of one unit of perspective is equal to the length of 20 units in the actual coordinate system.

[0017] Preferably, the coordinates of each coordinate system corresponding to the model graphics are calculated according to the actual image coordinates. The calculation formulas of the coordinates of each coordinate system are as follows:

[0018] The calculation formula for perspective coordinates is:

[0019] Px=(Fx–F.size / 2) / R

[0020] Py=–(Fy–F.size / 2) / R

[0021] The calculation formula of tile map coordinates is:

[0022] Tile.z = zoom level

[0023] Tile.c=Px / Tile.size=((Fx–F.size / 2) / R) / Tile.size

[0024] Tile.r=Py / Tile.size=(–(Fy–F.size / 2) / R) / Tile.size

[0025] The calculation formula of view coordinates is:

[0026] View.x=View.size.width / 2+(Fx–ViewCenterFigure.x) / R

[0027] View.y=View.size.height / 2–(Fy–ViewCenterFigure.y) / R

[0028] Among them, Px and Py represent the coordinate axis parameters of the perspective coordinate system; Tile.z, Tile.c and Tile.r represent the coordinate axis parameters of the tile coordinate system; View.x and View.y represent the coordinate axis parameters of the view coordinate system.

[0029] According to the coordinates, the perspective range corresponding to the current display range of the visual model diagram can be determined. After preparing the necessary parameters, the coordinates of the model diagram corresponding to each coordinate system can be calculated according to the above formula.

[0030] Preferably, step S3 comprises the following steps:

[0031] S31: Calculate the actual model range according to the actual model diagram coordinate system;

[0032] S32: Calculate the visible tile set within the current visible model range according to the zoom level of the current visible model graph, the current visible model range and the vector coordinates corresponding to the center point of the current visible model range; obtain corresponding data according to the tile pyramid storage data model, and obtain a vector graphic that intersects with the visible tile set;

[0033] S33: Calculate the visual model graph coordinates of the vector graphics, draw the vector model graph according to the visual model coordinates, and draw and display the GIM model graph;

[0034] S34: When the visual model is translated and scaled, the actual model coordinates corresponding to the center point of the visual model range are recalculated. The model is displayed according to the above process based on the calculation formula and the mapping relationship.

[0035] Preferably, the pre-fetching method in step S4 includes depth-first pre-fetching and breadth-first pre-fetching.

[0036] When building and loading data in the tile pyramid, due to the huge amount of data, a large amount of computer resources will be occupied, making the system response very slow. Therefore, by predicting the user's next operation, the data required for the next operation is cached during this idle time, that is, pre-retrieval processing.

[0037] Preferably, the depth-first pre-fetching process includes: pre-fetching the number of layers of the visible model image tile switching under the current viewing angle, and the number of columns and rows of tiles of any level contained in the range to be pre-fetched. The calculation formula of the range to be pre-fetched is:

[0038] NCViewCenterFigure.x=ViewCenterFigure.x / 2;

[0039] NCViewCenterFigure.y=ViewCenterFigure.y / 2;

[0040] Among them: NCViewCenterFigure indicates the range to be pre-fetched; ViewCenterFigure indicates the current visible model range. NCViewCenterFigure.x and NCViewCenterFigure.y are the coordinate axis parameters corresponding to the range boundaries of the depth-first pre-fetched range. ViewCenterFigure.x and ViewCenterFigure.y are the coordinate axis parameters corresponding to the current visible model range.

[0041] Tiles of all levels are stored in the form of a quadtree. Assuming that the number of tiles currently displayed is n, the number of tiles to be pre-fetched may be the previous layer n-1 or the next layer n+1. The visual model graph parameters can be obtained based on the coordinate transformation, and the data in the range to be pre-fetched can be pre-loaded into the cache.

[0042] Preferably, the breadth-first pre-retrieval process includes: before performing the translation operation, pre-caching the model image tile data of a certain adjacent area of ​​the visible range, and the calculation formula of the pre-retrieval range is:

[0043] ExViewCenterFigure.x=ViewCenterFigure.x+Δx

[0044] ExViewCenterFigure.y=ViewCenterFigure.y+Δy

[0045] Where: ExViewCenterFigure represents the pre-fetched range; ViewCenterFigure represents the current visible model range; Δx and Δy are the current tile layer expansion coefficients. ExViewCenterFigure.x and ExViewCenterFigure.y are the coordinate axis parameters corresponding to the range boundaries of the breadth-first pre-fetched range.

[0046] The substantial effect of the present invention is as follows: the present invention mainly adopts vector graphics algorithm and pyramid rule to optimize the GIM model, screens, groups and transforms the model within the visible range to reduce the amount of computing data, further improves the drawing efficiency and performance, and finally performs a pre-call method to cache the model data after the next scene change, thereby improving the efficiency of model display after the scene change. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1 A schematic flow chart of the main implementation steps of this embodiment;

[0048] Figure 2 This is a schematic diagram of the tile pyramid structure of this embodiment;

[0049] Figure 3 This is a cache flow chart in depth tile pre-fetching in this embodiment;

[0050] Figure 4 This is a cache flow chart of the breadth tile pre-fetching in this embodiment.

[0051] Among them: 1. Extension area, 2. Display area. DETAILED DESCRIPTION

[0052] The specific implementation of the present invention will be further described below through specific examples in conjunction with the accompanying drawings.

[0053] A method for optimizing the display of massive GIM models, such as Figure 1 As shown, the following steps are included:

[0054] S1: Construct coordinate system: Construct multiple coordinate systems and the relationship between different coordinate systems for different models;

[0055] S2: Coordinate transformation: implement coordinate transformation and calculate the number of layers for tile switching;

[0056] S3: Drawing and displaying: drawing and displaying the GIM model diagram according to the calculation formula and mapping relationship;

[0057] S4: Pre-retrieval processing: construct tile pyramid data from the original model data for pre-retrieval.

[0058] The model data information is obtained according to the pyramid rule and the model graph data is processed to obtain the final display model graph. Figure 2 , Tile pyramid structure diagram, the lower tile layer is a small-scale tile obtained by cutting the original data, and the scale increases as it goes up. Similar to the principle of human vision, the closer the human eye is to the object, the more obvious the details of the object are, and the higher the accuracy is; when the center point of the visible model range is closer to the object, the tiles with large scale and low longitude are replaced with tiles with small scale and high longitude. After the model graph pyramid is established, the tiles are stored in layers. When requesting model graph data, determine which level of tiles are needed according to the current viewing angle range, and then retrieve the tile data of that level. Finally, splice the retrieved tile data to quickly obtain the displayed GIM model. Finally, pre-retrieve the data according to the current data, and quickly display the model for subsequent viewing angle changes.

[0059] The specific implementation steps of this embodiment are as follows:

[0060] 1. Construct a coordinate system.

[0061] Construct multiple coordinate systems for different common models, as well as the relationship between different coordinate systems.

[0062] (1) Actual model diagram coordinate system. Given a square range, all GIM models can be drawn within this range. This range is called the actual model diagram and is represented by F. The coordinate system corresponding to the actual model diagram is called the actual model diagram coordinate system. The center of the actual model is the coordinate origin. The coordinates to the right and upward of the origin are positive. F represents the coordinates. Models are represented and stored in the numerical value of this coordinate system.

[0063] (2) Perspective model coordinate system. The actual model is projected at a given zoom level. The rectangle formed by the projection boundary is called the perspective model, denoted by P. The coordinate system within the perspective model is called the perspective model coordinate system. The upper left corner of the projection is the origin of the coordinate system. The origin is positive to the right and downward. P represents the coordinate.

[0064] (3) Tile model image coordinate system. Given a tile size (represented by Tile.size), the perspective model of a given zoom level is divided into tiles. The coordinate system that represents the perspective model with tiles as units is called the tile model image coordinate system. The upper left corner of the perspective model image is the origin of the coordinate system. The origin is positive to the right and downward. Tile(z,c,r) represents the zoom level, number of columns, and number of rows, respectively, and they are all positive integers.

[0065] (4) Visual model coordinate system. The area where the computer draws the model is called the visual model diagram, which is represented by View. The coordinate system corresponding to the visual model is called the visual model coordinate system. The upper left corner of the visual model diagram is the origin of the coordinate system. The coordinates are positive to the right and downward from the origin. View represents the coordinates. The visual model coordinate system is equivalent to translating the origin of the perspective coordinate system.

[0066] 2. Coordinate conversion.

[0067] In order to achieve coordinate transformation and calculate the number of layers for tile switching, the following parameters need to be determined:

[0068] (1) Actual image size. Usually, the actual model is agreed to be a cube, whose size includes all vector graphics, and F.size represents the side length of the cube.

[0069] (2) Tile calculation formula. The tile calculation formula is a pyramid model, and generally TileCount=4ZoomLevel is used to calculate the number of tiles per level.

[0070] (3) Tile size (Tile.size). Tiles are usually represented by cubes.

[0071] (4) Resolution (R). Resolution is the scale ratio of the actual image. In the perspective coordinate system corresponding to a certain zoom level, the length of the actual coordinate system corresponding to one unit of length is called resolution. For example, 1:20 means that the length of one unit of perspective is equal to the length of 20 units in the actual coordinate system. Resolution is related to the actual image size (F.size), tile size and number of tiles. The formula is:

[0072] R = F.size / (TileCount 1 / 2 *Tile.size)

[0073] (5) The actual figure coordinates ViewCenterFigure represented by the center coordinates of the visual model figure. Based on this coordinate, the perspective range corresponding to the current display range of the visual model figure can be determined. After preparing the necessary parameters, the coordinates of the model figure corresponding to each coordinate system can be calculated according to the following formula.

[0074] a. Given the actual image coordinates F(x,y), calculate the perspective image coordinates P(x,y)

[0075] Px=(Fx–F.size / 2) / R

[0076] Py=–(Fy–F.size / 2) / R

[0077] b. Knowing the actual image coordinates F, calculate the tile coordinates Tile (z, c, r)

[0078] Tile.z = zoom level

[0079] Tile.c=Px / Tile.size=((Fx–F.size / 2) / R) / Tile.size

[0080] Tile.r=Py / Tile.size=(–(Fy–F.size / 2) / R) / Tile.size

[0081] c. Knowing the actual image coordinates F, calculate the view coordinates View(x,y)

[0082] View.x=View.size.width / 2+(Fx–ViewCenterFigure.x) / R

[0083] View.y=View.size.height / 2–(Fy–ViewCenterFigure.y) / R

[0084] 3. Draw the display.

[0085] According to the calculation formula and mapping relationship, the model is displayed according to the following process:

[0086] (1) The actual model range can be calculated based on the actual model coordinate system;

[0087] (2) According to the zoom level of the current visual model graph, the current visual model range and the vector coordinates corresponding to the center point of the current visual model range, the visible tile set within the current visual model range can be calculated, and the corresponding data and the vector graphics that intersect with the visible tile set can be quickly obtained according to the tile pyramid storage data model;

[0088] (3) Calculate the visual model graph coordinates of the vector graphics, and then draw the vector model graph based on the visual model coordinates, so as to draw and display the GIM model graph;

[0089] (4) If the visual model is translated or scaled, the actual model coordinates corresponding to the center point of the visual model range need to be recalculated.

[0090] 4. Pre-retrieval processing.

[0091] The original model data is constructed into a tile pyramid data for pre-retrieval method. When constructing and loading data in the tile pyramid, due to the huge amount of data, a large amount of computer resources will be occupied, making the system response very slow. Therefore, it often takes a short time to wait for the user to operate before retrieving data. After operations such as zooming in and out, the currently displayed model graph data is generally examined, and then the next operation is started. During this period, there will be a period of idle time. Therefore, we can predict the user's next operation and cache the data required for the next operation during this idle time, that is, pre-retrieval processing. When pre-retrieval, the current display tile level is known, and it is only necessary to pre-retrieve based on the tile.

[0092] (1) Depth-first pre-fetch the number of layers of tiles to be switched in the visual model graph under the current viewing angle, as well as the number of columns and rows of tiles of any level contained in the range. Tiles of each level are stored in the form of a quadtree. Assuming that the number of tiles currently displayed is n, the number of tiles to be pre-fetched may be the previous level n-1 or the next level n+1.

[0093] Assume that the tile currently displayed by the user is Figure 3 (middle), showing that all tile data has been cached, so the next thing to cache is Figure 3 (right) Tile data. Assume the zoom level of the next-level tile model figure is 1 / 2, then calculate the range NCViewCenterFigure that needs to be pre-fetched based on the current visible model range ViewCenterFigure:

[0094] NCViewCenterFigure.x=ViewCenterFigure.x / 2;

[0095] NCViewCenterFigure.y=ViewCenterFigure.y / 2;

[0096] Therefore, the visual model parameters can be obtained according to the coordinate transformation in step 3 above and pre-loaded into the cache.

[0097] (2) Breadth-first pre-retrieval

[0098] This method is to reduce the time consumed when panning. Similar to depth-first pre-fetching, before panning, the model image tile data of a certain adjacent area in the visible range is pre-cached. Figure 4 As shown, it includes a display area 2 and an extended area 1. The display area 2 is the tiles that have been cached and displayed currently, and the extended area 1 is an area that may be displayed in a translation manner, that is, a pre-cached area.

[0099] The extended screen coordinate range is set by the current visible model range ViewCenterFigure, that is, the pre-fetched range ExViewCenterFigure, with expansion coefficients of Δx and Δy in the current tile layer:

[0100] ExViewCenterFigure.x=ViewCenterFigure.x+Δx

[0101] ExViewCenterFigure.y=ViewCenterFigure.y+Δy

[0102] Therefore, the visual model graph parameters can be obtained according to the coordinate transformation in step 3 above and pre-loaded into the cache.

[0103] This embodiment can be adapted to GIM data files that contain a large number of GIM models that need to be displayed. The corresponding graphic data can be quickly obtained according to the constructed tile pyramid data, and then the actual model map coordinates corresponding to the visible model map range that needs to be obtained in the actual scene are obtained, and the corresponding model is drawn. When a large amount of GIM model data is displayed, the diversity of models can be quickly rendered, and the graphics can be quickly displayed, which improves the user experience.

[0104] The above embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention.

Claims

1. A method for optimizing the display of massive GIM models, characterized in that: The steps include: S1: Constructing coordinate systems: Construct multiple coordinate systems and the relationships between different coordinate systems for different models. The constructed coordinate systems include the actual model map coordinate system, the perspective model map coordinate system, the tile model map coordinate system and the visual model coordinate system; S2: Coordinate transformation: implement coordinate transformation and calculate the number of layers for tile switching; S3: Drawing and displaying: drawing and displaying the GIM model diagram according to the calculation formula and mapping relationship; The step S3 comprises the following steps: S31: Calculate the actual model range according to the actual model diagram coordinate system; S32: Calculate a visible tile set within the current visual model range according to the zoom level of the current visual model graph, the current visual model range and the vector coordinates corresponding to the center point of the current visual model range; Obtain corresponding data according to the tile pyramid storage data model, and obtain a vector graphic that intersects with the visible tile set; S33: Calculate the visual model graph coordinates of the vector graphics, draw the vector model graph according to the visual model coordinates, and draw and display the GIM model graph; S34: when the visual model is translated and scaled, the actual model coordinates corresponding to the center point of the visual model range are recalculated; S4: Pre-retrieval processing: construct tile pyramid data from the original model data for pre-retrieval.

2. The method for optimizing and displaying a massive amount of GIM models according to claim 1, characterized in that: The parameters involved in the coordinate conversion process in step S2 include: actual image size, number of tiles at each level, tile size, resolution, and actual image coordinates represented by the center coordinates of the visual model image.

3. The method for optimizing and displaying a massive amount of GIM models according to claim 2, characterized in that: The resolution is related to the actual image size, tile size and number of tiles, and the formula is: R=F.size / (TileCount 1 / 2 *Tile.size) Among them, R is the resolution; F.size is the actual image size; TileCount is the number of tiles; Tile.size is the tile size.

4. The method for optimizing and displaying a massive amount of GIM models according to claim 2, characterized in that: The coordinates of the model graphics corresponding to each coordinate system are calculated according to the actual image coordinates. The calculation formulas for the coordinates of each coordinate system are as follows: The calculation formula for perspective coordinates is: Px=(Fx–F.size / 2) / R Py=–(Fy–F.size / 2) / R The calculation formula of tile map coordinates is: Tile.z = zoom level Tile.c=Px / Tile.size=((Fx–F.size / 2) / R) / Tile.size Tile.r=Py / / Tile.size=(–(Fy–F.size / 2) / R) / Tile.size The calculation formula of view coordinates is: View.x=View.size.width / 2+(Fx–ViewCenterFigure.x) / R View.y=View.size.height / 2–(Fy–ViewCenterFigure.y) / R Among them, Px and Py represent the coordinate axis parameters of the perspective coordinate system; Tile.z, Tile.c and Tile.r represent the coordinate axis parameters of the tile coordinate system; View.x and View.y represent the coordinate axis parameters of the view coordinate system; Fx represents the x-axis coordinate of the actual image; F.size represents the actual image size; Fy represents the y-axis coordinate of the actual image; View.size.width represents the width of the view; View.size.height represents the height of the view; ViewCenterFigure.x represents the x-axis coordinate of the actual image represented by the center coordinates of the visual model image; ViewCenterFigure.y represents the y-axis coordinate of the actual image represented by the center coordinates of the visual model image.

5. A method for optimizing the display of massive GIM models according to claim 1 or 4, characterized in that: The pre-fetching method in step S4 includes depth-first pre-fetching and breadth-first pre-fetching.

6. The method for optimizing and displaying a massive amount of GIM models according to claim 5, characterized in that: The depth-first pre-fetching process includes: pre-fetching the number of layers of the visible model image tile switching under the current viewing angle, and the number of columns and rows of tiles of any level contained in the range to be pre-fetched. The calculation formula of the range to be pre-fetched is: NCViewCenterFigure.x=ViewCenterFigure.x / 2 NCViewCenterFigure.y=ViewCenterFigure.y / 2 Among them: NCViewCenterFigure represents the range that needs to be pre-fetched; ViewCenterFigure represents the current visible model range.

7. The method for optimizing and displaying a large amount of GIM models according to claim 5, characterized in that: The process of breadth-first pre-retrieval includes: before performing the translation operation, pre-caching the model image tile data of a certain adjacent area of ​​the visible range, and the calculation formula of the pre-retrieval range is: ExViewCenterFigure.x=ViewCenterFigure.x+Δx ExViewCenterFigure.y=ViewCenterFigure.y+Δy Among them: ExViewCenterFigure represents the pre-loaded range; ViewCenterFigure represents the current visible model range; Δx and Δy are the current tile layer expansion coefficients.

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