CN102074004B - Method and device for determining type of barrier of spatial entity - Google Patents

Abstract

The invention discloses a method and a device for determining the type of a barrier of a spatial entity, and the method comprises the following steps: selecting the current spatial entity to be analyzed from the spatial entities which are sequenced according to preset sequencing rules and need to be analyzed; transforming an original coordinate of original spatial data of the current spatial entity to be analyzed, and getting a view coordinate of a view window; and analyzing the type of the barrier of the spatial entity in the view window. With the adoption of the method which is closed by the embodiment of the invention and used for determining the type of the barrier of the spatial entity, the barrier situation of the spatial entity in the view window during display can be determined according to preset view control parameters, thereby simplifying the computational process of barrier computation among the spatial entities, reducing the computational work, improving the determinationefficiency of the type of the barrier and solving the problem of complex and difficult real-time judgment process of the type of the barrier for the massive spatial entities.

Description

Method and device for judging space entity occlusion type

technical field

The invention relates to the fields of spatial information technology, computer graphics and computer operating systems, and in particular to a method and device for judging the occlusion type of a spatial entity.

Background technique

With the rapid development of spatial information technology, the high-resolution and high-precision spatial data acquired is growing explosively, but a series of problems need to be solved, especially the real-time Quick transfer and display issues.

The main representation of spatial entities is through electronic maps. Electronic maps are visual maps that display spatial entities on electronic screens through certain hardware and software. Spatial entities are displayed in a grid on the view window of electronic screens. process. The attributes and graphical information assigned to spatial entities for display on the electronic map are called elements. Point entities correspond to point features, line entities correspond to line features, and area entities correspond to area features. Among them, the graphical information of spatial entities and the graphical information of point elements generally include: point symbol type, symbol size, and symbol color; the graphical information of lines includes: line symbol type, line symbol width, line shape The color of the symbol; the graphic information of the surface includes: the filling type of the surface (such as whether it is transparent), the type of the surface symbol, and the filling color of the surface. Some spatial entities themselves record the graphic information of the spatial entity, and some set unified graphic information for the same type of spatial entity according to the layer when the electronic map is displayed.

The above-mentioned rasterization refers to the conversion of spatial data representing graphics in a vector graphics format into a raster image. Each pixel value of a raster image usually represents a color value for display on a monitor, printout on paper, and image file generation output process.

In the process of processing spatial entities, in some cases, it is necessary to determine the occlusion type of the spatial entity, that is, to analyze whether the spatial entity is blocked by other spatial entities, the data of the spatial entity that needs to be determined in the prior art The quantity is large, the efficiency of the determination process is low, and the determined spatial entity cannot be guaranteed to be displayed in the view window, and the determination effect is also poor.

Contents of the invention

In view of this, the present invention provides a method and device for judging the occlusion type of a spatial entity to solve the problems in the prior art that the occlusion type judgment process for massive spatial data is complicated, the processing efficiency is low, and the judgment effect is poor. The specific solution is as follows :

A method for judging the occlusion type of a spatial entity, comprising:

Select the current spatial entity to be analyzed from the spatial entities to be analyzed sorted according to the preset sorting rules;

Transforming the original coordinates of the original spatial data of the current spatial entity to be analyzed according to the preset view control parameters to obtain the view coordinates of the view window;

analyzing the occlusion type of the spatial entity in the view window;

Judging whether the occlusion type of the space entity meets the preset valid space entity condition, if so, determining that the space entity is a valid space entity, and if not, determining that the space entity is an invalid space entity;

selecting the active space entity;

The live space entity is transmitted to the client.

Preferably, the view window is represented by a data structure according to the view control parameters, specifically: using the grid data structure to represent the pixels of the view window according to the view control parameters, and the pixels are the The view window plane is divided into uniform grid units, the pixel is the basic information storage unit in the raster data, and the coordinate position of the pixel is based on the corresponding row number and column number of the pixel in the view window OK, set the initial values of the raster data representing the pixel to all 0.

Preferably, the process of analyzing the occlusion type of the spatial entity in the view window includes:

Determine whether the values of the pixels that need to be drawn when the spatial entity is displayed in the view window are all 1, if all are 1, then the occlusion type is complete occlusion; if all are 0, then the occlusion type is not Occluded; if part is 1, the occlusion type is partial occlusion.

Preferably, when the occlusion type of the spatial entity is not occluded and/or partially occluded, a pixel with a pixel value of 0 among the pixels to be drawn when the spatial entity is displayed on the view window is assigned a value of 1.

Preferably, the preset conditions for valid spatial entities include: the occlusion type is an unoccluded spatial entity or the occlusion type is an unoccluded and partially occluded spatial entity.

Preferably, the view control parameters include: a view mode and an outer rectangle parameter of the view window; the view mode includes: a two-dimensional mode and a three-dimensional mode, and the outer rectangle parameters of the view window include: the width of the outer rectangle of the view window and The height of the bounding rectangle of the view window;

When the view mode is a two-dimensional mode, the view control parameters also include: the central coordinate point of the spatial entity in the view window and the magnification ratio of the spatial entity in the view, or query the rectangular range and view of the spatial entity The magnification ratio of the spatial entity;

When the view mode is a three-dimensional mode, the view control parameters also include: viewpoint parameters and projection parameters, the viewpoint parameters include the position of the viewpoint in the world coordinate system, the target position observed by the viewpoint and the upward vector of the virtual camera ; The projection parameters include: orthogonal projection and perspective projection.

Preferably, when the view mode in the view control parameter is a two-dimensional mode, the preset sorting rule is to sort the spatial entities in the reverse order of the drawing order of the spatial entities.

Preferably, when the view mode in the view control parameter is a three-dimensional mode, the preset sorting rule is to sort the spatial entities in the order of the spatial entities from the viewpoint to the farthest.

A device for judging the occlusion type of a spatial entity, comprising:

The selection unit is used to select the current spatial entity to be analyzed from the spatial entities to be analyzed sorted according to the preset sorting rules;

The coordinate conversion unit transforms the original coordinates of the original spatial data of the current spatial entity to be analyzed according to the preset view control parameters to obtain the view coordinates of the view window;

an occlusion type analysis unit, configured to analyze the occlusion type of the spatial entity in the view window;

A judging unit, configured to judge whether the occlusion type of the space entity meets the preset valid space entity condition, if so, determine that the space entity is a valid space entity, and if not, determine that the space entity is an invalid space entity;

The selection unit is configured to select the effective space entity and transmit the effective space entity to the client.

It can be seen from the above technical solutions that the method for judging the occlusion type of the spatial entity disclosed in the embodiment of the present invention converts the original coordinates of the original spatial data of the spatial entity according to the preset view control parameters to obtain the view coordinates in the view window, By analyzing the view coordinates to determine the occlusion situation when the spatial entity is displayed, the calculation process of occlusion calculation between spatial entities in the prior art is simplified, the calculation amount is reduced, and the determination efficiency of the occlusion type is improved. It solves the problem of complex and difficult real-time judgment process of the occlusion type of massive spatial entities.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention. Those skilled in the art can also obtain other drawings based on these drawings without creative work.

FIG. 1 is a flow chart of a method for judging a spatial entity occlusion type disclosed in an embodiment of the present invention;

FIG. 2 is a flowchart of a method for determining an effective space entity disclosed in an embodiment of the present invention;

Fig. 3 is a schematic structural diagram of an apparatus for determining the type of occlusion of a spatial entity disclosed in an embodiment of the present invention.

Detailed ways

The following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only some, not all, embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present invention.

The present invention studies spatial data from the perspective of view display. From the perspective of view, when the resolution of the view window is determined, no matter how massive and fine the spatial data is, the maximum effective spatial data required for view window display It is constant, that is, the spatial data required to fill all the pixels of the view window, because the total number of pixels that the view window can display is limited, no matter how large the amount of spatial data is, the pixels we can see are determined, If the spatial entity drawn first is covered by the spatial entity drawn later, it means that the spatial entity drawn later blocks the spatial entity drawn earlier. If it is completely occluded, the spatial entity that is completely occluded from the perspective of view display is Nothing that needs to be read, transferred, or drawn on the view window.

Specifically, the display process of a spatial entity is generally as follows: firstly, the spatial entity that meets the given spatial conditions is taken out through the spatial data index and transmitted to the user of the spatial entity through the transmission medium, that is, the client, and then the spatial data of the spatial entity is processed. After a series of geometric transformations and processing, it is transformed into coordinate points on the two-dimensional image; according to the display parameters, the spatial entity is finally rasterized into image pixels through a drawing algorithm, drawn into a two-dimensional raster image, and displayed or output on the screen. Such as computer screen display, printing output on paper and generating image file output, etc. Among them, the drawing of the spatial entity is finally attributed to the operation of each pixel by the drawing algorithm. The present invention is based on the above-mentioned spatial data display process, and according to the preset view control parameters, the original spatial data of the spatial entity is Transform the original coordinates to the view coordinates of the view window represented by the view control parameters using the data structure, and analyze the position of the spatial entity on the view window that is actually displayed by analyzing and processing the pixels that need to be drawn when the spatial entity is displayed on the view window Display the situation, and then analyze the occlusion situation between the spatial entities, so that the subsequent processing process can select or transmit the spatial entities in a targeted manner according to the analysis results, simplifying the process and calculation amount of occlusion type calculation in the prior art, and improving efficiency and accuracy of judgment. For the convenience of description, in this application document, the spatial data of the spatial entity to be processed is called the original spatial data, the coordinates of the spatial data to be processed are called the original coordinates of the original spatial data, and the coordinate points of the spatial data to be processed are called It is the original coordinate point of the original spatial data, or directly called the original coordinate point. Its specific implementation is as follows:

The flow of a method for determining the occlusion type of a spatial entity disclosed in an embodiment of the present invention is shown in Figure 1, including:

Step S11. Select the current spatial entity to be analyzed from the spatial entities to be analyzed sorted according to the preset sorting rules;

When the view mode in the view control parameter is a two-dimensional mode, the preset sorting rule is to sort the spatial entities in reverse order of the drawing order of the spatial entities. When the view mode in the view control parameter is a three-dimensional mode, the preset sorting rule is to sort the spatial entities in the order of the spatial entities from the viewpoint to the farthest.

Step S12, transforming the original coordinates of the spatial data of the current spatial entity to be analyzed according to the preset view control parameters to obtain the view coordinates of the view window;

The view control parameters in this embodiment include: view mode and surrounding rectangle parameters of the view window. The view mode is to pre-set the view window as 2D mode or 3D mode according to the actual view window. The outer rectangle parameter of the view window is the view window range (0, 0, ViewWidth, ViewHeight) of the display space entity, such as the scope of the computer screen map display window, including: the width of the outer rectangle of the view window ViewWidth and the outer rectangle of the view window Height ViewHeight, through these two parameters, you can determine the size range of the window used to display images in the actual view window. At the same time, the size of the raster data used to represent the view window can be obtained. If m bytes are used to represent a pixel value, then the size of the grid data of the view window is: (ViewWidth*ViewHeight*m). And the initial value of the raster data used to represent the view window is assigned 0.

In addition to including the view mode and the surrounding rectangle parameters of the view window, the specific content of the view control parameters is also different according to the view mode. When the view mode is two-dimensional mode, it also includes the rectangular range of the query spatial entity and the magnification ratio of the spatial entity in the view, and can also use the central coordinate point of the spatial entity under the view window to replace the rectangular range of the query spatial entity , as long as the original coordinates of the original spatial data can be transformed to obtain the view coordinates of the view window. Querying the rectangular range of a spatial entity refers to displaying the spatial entity within this range in the view window, that is, the surrounding rectangle of the spatial entity that can be displayed in the view window. The specific range value is set according to the actual display situation . When the view mode is a three-dimensional mode, it also includes viewpoint parameters and projection parameters, and the viewpoint parameters include the position O(x _o , y _o , z _o ), x _o , y _o of the viewpoint in the preset world coordinate system , z _o represents the three components of the viewpoint in the world coordinate system, the target position A(x _a , y _a , z _a ) observed by the viewpoint and the upward vector up(x _up , y _up , z _up ) of the virtual camera; The projection parameters include: orthogonal projection and perspective projection. Or the view matrix and projection matrix obtained according to the above parameters are used to perform coordinate transformation. Transform the original coordinates of the original space data into the view coordinates of the view window in the corresponding mode according to different view control parameters.

The data corresponding to the view coordinates is view data, and after the view control parameters are determined, the view window is represented by the data structure according to the view control parameters. The display view window mentioned here may be a physical view window that can be actually displayed, or a logical view window environment generated for analysis.

When the view window is represented by a raster data structure, the two-dimensional raster image is represented by raster data, and the display view window plane is divided into uniform grids. Each grid unit is called a pixel, and the raster data structure is a pixel array. , each pixel in the raster is the most basic information storage unit in raster data, and its coordinate position can be determined by row number and column number. Since raster data is arranged according to certain rules, the positional relationship of spatial entities represented is implicit in the row number and column number. Each pixel value is used to represent an attribute or an encoding of an attribute of a spatial entity.

According to the preset view control parameters, the original coordinates of the received original space data are transformed to obtain the view coordinates in the view window coordinate system. The original coordinate points of the original space data correspond to the view coordinate points in the view window coordinate system. Each view The coordinate points correspond to the pixels of the view window represented by the grid data according to the view control parameters. By analyzing the pixels that need to be drawn when the spatial entity is displayed on the view window, it is analyzed that the spatial entity is displayed on the view window that is actually displayed. occlusion situation.

Step S13, analyzing the occlusion type of the spatial entity in the view window;

The occlusion types include: full occlusion, which means that the spatial entity is completely occluded by other spatial entities; partial occlusion, which means that the spatial entity is partially occluded by other spatial entities; not occluded, which means that the spatial entity is not occluded by other spatial entities.

The specific judgment process can obtain the pixels that the spatial entity needs to draw when the spatial entity is displayed in the view window by simulating the display process of the spatial entity on the actual view window. After transformation and processing, it is transformed into coordinate points on the two-dimensional image; according to the display parameters, the spatial entity is finally rasterized into image pixels through a drawing algorithm, drawn into a two-dimensional raster image, and displayed or output on the screen. The present invention is based on the above-mentioned process, obtains the pixel that needs to be drawn when the spatial entity is displayed on the view window through the view coordinates according to the drawing algorithm (such as the Bresenham algorithm for line segment drawing), and then judges the value of the pixel that needs to be drawn, If all are 1, the occlusion type is full occlusion; if all are 0; then the occlusion type is unoccluded; if part is 1, the occlusion type is partial occlusion, that is, as long as If there is a pixel value of 1 among the pixels to be drawn, the spatial entity is blocked by other spatial entities. As long as there is a pixel value of 0 among the pixels to be drawn, the spatial entity is not completely blocked by other spatial entities.

When the spatial entity is not completely occluded by other spatial entities, that is, when the occlusion type of the spatial entity is not occluded and/or partially occluded, if it is necessary to mark the spatial entity for drawing on the pixel, you can When the spatial entity is displayed on the view window, the pixels with a pixel value of 0 are assigned a value of 1, so as to ensure that in the subsequent process of determining the occlusion type of the spatial entity, if there are other spatial entities, they must also be in the above-mentioned If it is displayed on the pixel, it will be judged as blocked to ensure the accuracy of the judgment process.

The analysis or processing of the view coordinates in this embodiment is performed by combining a single pixel or multiple pixels, and a specific processing method can be flexibly set according to actual needs. Its specific operations for pixels include not only assigning values to pixels, that is, rasterizing spatial data, but also reading pixels and judging pixel values. When pixels are represented by multiple bits, the assignment to pixels can be It is expressed as assigning a value to a pixel as a whole or assigning a value to any one or more of the multiple bits representing the pixel; the operation of reading a pixel can also be expressed as reading the overall value of a pixel and reading a certain value in a pixel The value of one or several bits; similarly, the judgment of the pixel value is also the judgment of the overall value of a pixel or the meaning represented by the value of one or several bits.

For example, use 4 bits of data to represent a pixel of the simulated view window, where the first bit indicates whether a point element is rasterized on this pixel, and the second bit indicates whether a line element is rasterized on this pixel The third bit is whether there is a surface element to be rasterized on this pixel, and the fourth bit is used for the simplification of the space vector data. First define a few constants:

For example, the pixel operation method corresponding to the line space entity is as follows:

Pixel assignment operation: Use the OR operation of the defined constant line and the pixel value to assign a value to the pixel to realize the rasterization of the original spatial data. For example, for P(x, y) pixel line rasterization operation, P(x, y) = P(x, y) line; clear the original space data rasterization operation, use the defined constant line to invert and then the same pixel Value AND operation to clear, such as clearing P(x, y) pixel line rasterization operation, P(x, y)=P(x, y)&～line.

Read the pixel value: the value of the raster data of P(x, y) is the value of the P(x, y) pixel;

Pixel value determination operation: For example, to determine whether the pixel is rasterized by the original spatial data, use the AND operation of the defined constant line and the pixel value to determine. If it is determined whether the P(x, y) pixel is rasterized by the line, it is determined whether the value of P(x, y)&line is greater than 0. If it is greater than 0, the P(x, y) pixel is gridded by the line space entity If it is equal to 0, the P(x, y) pixel is not rasterized by the line space entity.

The pixel operations corresponding to other spatial entities can also be operated according to the above method.

After this step, you can also include:

Step S14, judging whether there is an unprocessed spatial entity to be analyzed, if yes, execute step S15, if not, end;

Step S15 , judging whether there are unprocessed pixels in the view window, if yes, return to step S11 , if not, end.

In the method for judging the occlusion type of the spatial entity disclosed in this embodiment, the occlusion of the spatial entity when it is actually displayed on the view window is analyzed by analyzing the pixels that need to be drawn when the spatial entity is displayed on the view window, It ensures that the calculation of occlusion calculation between spatial entities is small, and the algorithm is simple and efficient, which solves the problem of complex and difficult real-time judgment of the occlusion type of massive spatial entities, and improves the efficiency of judgment and the accuracy of judgment results.

The present invention also discloses a method for judging a space entity as an effective space entity based on the above-mentioned judging method of the occlusion type of the space entity, and the effective space entity is a space entity that can be displayed after drawing pixels in a view window. The specific process is shown in Figure 2. The method disclosed in this embodiment is applied to the server side, taking the two-dimensional view mode as an example, including:

Step S21, selecting the current spatial entity to be analyzed from the spatial entities sorted according to the reverse order of the drawing order of the spatial entities;

Step S22: Transform the original coordinates of the spatial data of the current spatial entity to be analyzed according to the preset view control parameters to obtain the view coordinates of the view window;

The view control parameter in this embodiment is the view control parameter of the actually displayed view window of the client.

Step S23, judging whether the values of the pixels that need to be drawn when the spatial entity is displayed in the view window are all 1, if so, then perform step S24a, if all are 0, then perform step S24b, if some are 1, Then execute step S24c;

Step S24a, determining that the occlusion type is complete occlusion;

Step S24b, determining that the occlusion type is not occluded;

Step S24c, determining that the occlusion type is partial occlusion;

Step S25, judging whether the occlusion type meets the preset effective space entity condition, if yes, execute step S26a, if not, execute step S26b;

The preset effective spatial entity condition in this embodiment is a spatial entity whose occlusion type is not occluded.

Step S26a, determine that the space entity is a valid space entity, and execute step S27;

Step S26b, determine that the space entity is an invalid space entity, and execute step S28;

Step S27 , assigning a value of 1 to the pixel that needs to be drawn when the effective spatial entity is displayed on the view window, to indicate that the spatial entity has already been drawn on the pixel.

When it is necessary to indicate that the effective space entity is drawn on the pixel, the pixel that needs to be drawn when the effective space entity is displayed on the view window can also be assigned a value of 1, which is used to indicate that the pixel has been used for display The effective spatial entity is used to ensure that the pixel value that has been used to display the effective spatial entity is used as the basis for the judgment in the subsequent determination of the occlusion type of the spatial entity. If there are other spatial entities that are also displayed on the above-mentioned pixels, they will be blocked. , to ensure the accuracy of the judgment process. At the same time, if the spatial entity has graphical information, the graphical information should be considered during analysis and processing. For example, the graphical information of the surface entity is transparent or semi-transparent. If the surface entity is a valid spatial entity, but the surface entity All pixels to be drawn are not assigned a value of 1.

Step S28, judging whether there is an unprocessed spatial entity to be analyzed, if yes, execute step S29, if not, end;

Step S29 , judging whether there are unprocessed pixels in the view window, if yes, return to step S21 , if not, end.

The method for determining valid spatial entities disclosed in this embodiment pre-processes the spatial data requested by the client, and determines the valid spatial entities that can be effectively displayed in the actual view window according to the view control parameters actually displayed by the client. For the space entity, the step of selecting and transmitting the effective space entity can be added correspondingly in the follow-up, which ensures the lossless display of data, greatly reduces the amount of data transmission, and improves the efficiency of data transmission and display.

Apply this method to the server side, process the mass data of the spatial entity requested by the client according to the view control parameters of the view window displayed by the client, analyze the occlusion type of the spatial entity on the view window, and then judge the occlusion Whether the type meets the preset effective space entity conditions, so as to obtain effective data that can be displayed on the client without loss for transmission, without the need to transmit data that cannot be seen on the display interface of the client, reducing the amount of data transmission and improving transmission. efficiency.

The method for determining effective space entities disclosed in this embodiment does not limit its specific application scenarios. It can also be set on the client to determine the occlusion type of massive space entity data to be displayed, and according to the currently set effective space Entity conditions to determine the effective space entity for display, thus ensuring that the data that cannot be seen does not need to be displayed during the display process, and the display efficiency is improved. If it is applied in this scenario, the above steps can also include determining the effective space Steps for displaying spatial entities.

Of course, this embodiment does not limit the above two application scenarios, and the application scenarios of the method can be set according to actual application conditions, and can also be applied to both the client and the server. After the effective spatial entity is judged, subsequent processing such as simplification and progressive transmission of the data of the effective spatial entity may also be included, which will not be listed one by one here. The process of determining the effective space entity belongs to the protection scope of this embodiment.

The present invention also discloses a device for judging the occlusion type of a spatial entity, its structure is shown in Figure 3, comprising: a selection unit 31, a coordinate conversion unit 32, and an occlusion type analysis unit 33, wherein the selection unit 31 is used to select Select the current spatial entity to be analyzed from the spatial entities to be analyzed according to the sorting rules; the coordinate conversion unit 32 is used to transform the original coordinates of the original spatial data of the current spatial entity to be analyzed according to the preset view control parameters to obtain The view coordinates of the view window; the occlusion type analysis unit 33 is used to analyze the occlusion type of the spatial entity in the view window.

Among them, the processing process of each unit is as follows:

The selection unit selects the current spatial entity to be analyzed from the spatial entities to be analyzed sorted according to the preset sorting rules. If it is a two-dimensional mode, the default sorting rule is to sort in the reverse order of the drawing order of the spatial entities. If it is a three-dimensional mode, Then, the default sorting rule is to sort the spatial entities in the order of the distance from the viewpoint to the farthest, and select the sorted spatial entities in order. The coordinate transformation unit transforms the original coordinates of the spatial data of the selected spatial entity according to the view control parameters, transforms them into the view coordinates under the view window represented by the data structure according to the view control parameters, and uses the occlusion type analysis unit to analyze the spatial entity The occlusion type, the specific process includes judging whether the values of the pixels that the spatial entity needs to draw in the view window are all 1, if all are 1, then the occlusion type is complete occlusion; if all are 0, then the The occlusion type is not occluded; if part is 1, the occlusion type is partial occlusion, so as to determine whether the occlusion type of the currently analyzed spatial entity is fully occluded, partially occluded or not occluded.

After processing the current spatial entity, judge whether the spatial entity is the last spatial entity, if yes, end, if not, then judge whether there are unprocessed pixels in the view window represented by the data structure, if yes , according to the above sequence, select the next spatial entity and process it. If there are no unprocessed pixels in the view window, it will end until all spatial entities are processed, or there are no unprocessed pixels in the view window represented by the data structure. of pixels.

The device may also include an effective space entity determination unit, which pre-sets the conditions of an effective space entity, which may be an unoccluded space entity, or a partially occluded space entity, or a combination of the two. Whether the occlusion type of the spatial entity meets the conditions of a valid spatial entity, and if yes, then determine that the spatial entity is a valid spatial entity, and in the subsequent process, the pixels that need to be drawn when the valid spatial entity is displayed on the view window Assign a value of 1 to indicate that a spatial entity has been drawn on the pixel.

The execution process of the device for determining the occlusion type of a space entity disclosed in this embodiment corresponds to the flow of the method embodiment disclosed in the above-mentioned embodiment of the present invention, and is a preferred device embodiment. For the specific execution process, please refer to the above-mentioned method embodiment. I won't repeat them here.

The device for judging the occlusion type of a spatial entity disclosed in the present invention can be set in a computer, or in a mobile phone or other devices that can use the present invention, or other smart devices. It can be set on the server side to determine the occlusion type of the spatial entity before sending the data requested by the client, or it can be set on the client side to determine the occlusion type of the spatial entity before sending the spatial entity to the actual view window. The occlusion type of the spatial entity is judged, or it is set on the server and the client at the same time, and which side or both parties are selected to handle it according to the actual situation.

Each embodiment in this specification is described in a progressive manner, each embodiment focuses on the difference from other embodiments, and the same and similar parts of each embodiment can be referred to each other. As for the device disclosed in the embodiment, since it corresponds to the method disclosed in the embodiment, the description is relatively simple, and for the related information, please refer to the description of the method part.

Professionals can further realize that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented by electronic hardware, computer software or a combination of the two. In order to clearly illustrate the possible For interchangeability, in the above description, the composition and steps of each example have been generally described according to their functions. Whether these functions are executed by hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art may use different methods to implement the described functions for each specific application, but such implementation should not be regarded as exceeding the scope of the present invention.

The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be directly implemented by hardware, software modules executed by a processor, or a combination of both. Software modules can be placed in random access memory (RAM), internal memory, read-only memory (ROM), electrically programmable ROM, electrically erasable programmable ROM, registers, hard disk, removable disk, CD-ROM, or any other Any other known storage medium.

The above description of the disclosed embodiments is provided to enable any person skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention will not be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (6)

1. A method for judging a spatial entity occlusion type applied to a server, characterized in that it comprises: Select the current spatial entity to be analyzed from the spatial entities to be analyzed sorted according to the preset sorting rules; According to the view control parameters preset by the client, transforming the original coordinates of the original spatial data of the current spatial entity to be analyzed to obtain the view coordinates of the view window, the view control parameters include: view mode and the surrounding rectangle parameters of the view window; The view mode includes: two-dimensional mode and three-dimensional mode, and the surrounding rectangle parameters of the view window include: the width of the surrounding rectangle of the view window and the height of the surrounding rectangle of the view window; When the view mode is a two-dimensional mode, the view control parameters also include: the central coordinate point of the spatial entity in the view window and the magnification ratio of the spatial entity in the view, or query the rectangular range and view of the spatial entity The magnification ratio of the spatial entity; When the view mode is a three-dimensional mode, the view control parameters also include: viewpoint parameters and projection parameters, the viewpoint parameters include the position of the viewpoint in the world coordinate system, the target position observed by the viewpoint and the upward vector of the virtual camera ; The projection parameters include: orthogonal projection and perspective projection; When the view mode in the view control parameter is a two-dimensional mode, the preset sorting rule is to sort the spatial entities in the reverse order of the drawing order of the spatial entities; when the view mode in the view control parameters is a three-dimensional mode , the preset sorting rule is to sort the spatial entities in the order that the spatial entities are near and far from the viewpoint; analyzing the occlusion type of the spatial entity in the view window; Judging whether the occlusion type of the space entity meets the preset valid space entity condition, if so, determining that the space entity is a valid space entity, and if not, determining that the space entity is an invalid space entity; selecting the active space entity; The valid space entity is transmitted to the client. 2. The method according to claim 1, wherein the view window is represented by a data structure according to the view control parameters, specifically: representing the view by a grid data structure according to the view control parameters The pixel of the window, the pixel is a uniform grid unit divided into the plane of the view window, the pixel is the basic information storage unit in the raster data, and the coordinate position of the pixel is based on the pixel in the The corresponding row number and column number in the view window are determined, and the initial values of the raster data representing the pixel are all set to 0. 3. The method according to claim 2, wherein the process of analyzing the occlusion type of the spatial entity in the view window comprises: Determine whether the values of the pixels that need to be drawn when the spatial entity is displayed in the view window are all 1, if all are 1, then the occlusion type is complete occlusion; if all are 0, then the occlusion type is not Occluded; if part is 1, the occlusion type is partial occlusion. 4. The method according to claim 3, further comprising: when the occlusion type of the spatial entity is unoccluded and/or partially occluded, displaying the spatial entity on the view window Among the pixels that need to be drawn, the pixels with a pixel value of 0 are assigned a value of 1. 5 . The method according to claim 1 , wherein the preset conditions for valid spatial entities include: the occlusion type is an unoccluded spatial entity or the occlusion type is an unoccluded and partially occluded spatial entity. 5 . 6. A device for judging the type of spatial entity occlusion applied to the server, characterized in that it comprises: The selection unit is used to select the current spatial entity to be analyzed from the spatial entities to be analyzed sorted according to the preset sorting rules; The coordinate conversion unit transforms the original coordinates of the original spatial data of the current spatial entity to be analyzed according to the view control parameters preset by the client to obtain the view coordinates of the view window. The view control parameters include: view mode and view window Outer rectangle parameter; the view mode includes: two-dimensional mode and three-dimensional mode, the outer rectangle parameter of the view window includes: the width of the outer rectangle of the view window and the height of the outer rectangle of the view window; When the view mode is a two-dimensional mode, the view control parameters also include: the central coordinate point of the spatial entity in the view window and the magnification ratio of the spatial entity in the view, or query the rectangular range and view of the spatial entity The magnification ratio of the spatial entity; When the view mode is a three-dimensional mode, the view control parameters also include: viewpoint parameters and projection parameters, the viewpoint parameters include the position of the viewpoint in the world coordinate system, the target position observed by the viewpoint and the upward vector of the virtual camera ; The projection parameters include: orthogonal projection and perspective projection; When the view mode in the view control parameter is a two-dimensional mode, the selection unit selects the current spatial entity to be analyzed from the spatial entities to be analyzed that are sorted according to the reverse order of the drawing order of the spatial entities, when the view When the view mode in the control parameter is a three-dimensional mode, the selection unit selects the current spatial entity to be analyzed from the spatial entities to be analyzed that sort the spatial entities in the order of the spatial entities from the viewpoint to the farthest; an occlusion type analysis unit, configured to analyze the occlusion type of the spatial entity in the view window; A judging unit, configured to judge whether the occlusion type of the space entity meets the preset valid space entity condition, if so, determine that the space entity is a valid space entity, and if not, determine that the space entity is an invalid space entity; The selection unit is configured to select the effective space entity and transmit the effective space entity to the client.

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