JP2015187795A - image display system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a processing load in pasting a plurality of textures such as three-dimensional maps on a polygon so as to display an image.SOLUTION: The image display system provides an integrated texture that is formed by arranging multiple kinds of textures, to be pasted on polygon data representing a three-dimensional shape of an object such as a building, in such a way that the multiple kinds of textures are not overlapped with one another. When displaying a projection drawing of the object, the image display system reads the integrated texture, specifies a portion of the integrated texture corresponding to a polygon, and pastes only the portion. The image display system does not cut out the integrated texture to generate a new texture, but uses the integrated texture as it is to specify a portion to be pasted. Thus, only by reading the integrated texture, reading a plurality of textures is made unnecessary, the number of times for read processing can be reduced, and a load of the read processing and a load of displaying processing can be reduced.

Description

  The present invention relates to an image display system that displays an image by pasting a plurality of types of textures to a plurality of polygons.

In an electronic map used for a route guidance system or a computer screen, a three-dimensional map representing a three-dimensional feature such as a building may be used. A three-dimensional map is displayed by drawing a three-dimensional model three-dimensionally by perspective projection or the like, and each of the three-dimensional models constituting the three-dimensional model is disclosed in Patent Document 1 in order to improve the reality. Texture is pasted on the polygon.
FIG. 1 is an explanatory diagram showing an application example of texture in the prior art. As an example, an example of application to a three-dimensional building model is shown. Texture A representing the exterior of the roof is affixed to the upper surface of the building. Similarly, textures B and C are attached to the front and side surfaces of the building, respectively. In this example, textures B and C as unit images are repeatedly arranged and pasted on the front and side surfaces.

JP 2012-183100 A

The use of texture is indispensable for improving the reality of 3D maps. However, the pasting of the texture requires a great calculation load. The computational load increases so that it cannot be overlooked as the number of textures increases.
Such a problem is common not only when displaying a three-dimensional map but also when displaying an image using a texture.
The present invention has been made in view of the above problems, and an object thereof is to reduce the processing load of image display using texture.

The present invention
An image display system that displays images by pasting multiple types of textures to multiple polygons,
A texture data storage unit for storing integrated texture data representing images arranged at arbitrary positions so as not to overlap the plurality of types of textures;
An input unit for reading the polygon and attribute information for designating which of the plurality of types of textures are pasted on each polygon;
A display control unit that displays an image by pasting the texture on the polygon according to the attribute information;
The display control unit
The integrated texture data is read from the texture data storage unit, stored in the storage unit,
Based on the attribute information, specify a range on the storage unit in which the specified type of texture is stored,
The integrated texture data can be configured as an image display system that performs the pasting using data within the specified range.

Normally, a texture is displayed by repeating a series of processes for each texture after reading texture data based on a drawing command and drawing using the texture data. Therefore, when various textures are used for image display, it is necessary to repeat this series of processes for each texture as the types of textures increase. Issuing commands, texture images prepared in advance in the texture data storage unit The number of times data is read increases and the processing time increases. On the other hand, in the present invention, an integrated texture in which textures used for image display are arranged is used, so that image data corresponding to a plurality of textures is read from the texture data storage unit at once and rendered using the same. Therefore, it is possible to reduce the number of times the command is issued and read, and the processing time can be shortened.
In particular, the present invention is highly useful in an image display system including a circuit for interpreting an image display command and a circuit for executing a display process so as to be able to operate in parallel. For example, there is a system including a CPU (Central Processing Unit) and a GPU (Graphics Processing Unit). In such a system, when the CPU issues a command to the GPU, the GPU starts drawing. However, if the number of commands for drawing display increases, the GPU waits for the CPU to issue a command. Waste time occurs and the overall processing time becomes longer. On the other hand, in the present invention, the number of commands for drawing display can be reduced, so that processing can be performed while suppressing the occurrence of such dead time, and the processing time can be shortened.
In general, an image display system using textures has an upper limit on the number of textures that can be managed at one time for drawing. If drawing is performed using a number of textures exceeding the upper limit, it is necessary to update the managed texture at any timing, resulting in wasted time. On the other hand, according to the present invention, the total number of textures can be reduced by using the integrated texture. Therefore, the number of textures can be prevented from exceeding the manageable upper limit, and the dead time for updating the texture can be avoided.
Moreover, in this invention, the range corresponded to each texture among integrated textures can be specified, and each can be utilized for affixing. Therefore, it is possible to display an image in which each texture is used individually while using the integrated texture.

In the present invention, the attribute information is information for specifying a range on the storage unit in which each texture is stored. This specification may be information that directly specifies the storage area of the storage unit by an address or the like, or may be information that is specified indirectly. As the information to be indirectly specified, for example, coordinate information for specifying the range of each texture in the integrated texture can be considered.
In the present invention, it is not necessary for each texture included in the integrated texture and the polygon to have a one-to-one relationship. A texture may be used in combination with a plurality of polygons, or a plurality of textures may be applied by being superimposed on one polygon.
Further, it is not always necessary that all textures used in one image are included in one integrated texture, and an image may be displayed using a plurality of integrated textures.

In the image display system of the present invention,
Each of the plurality of types of textures has a rectangular shape,
The display control unit may specify a range in which the texture is stored based on vertex coordinates of the rectangular shape facing each other.

Thus, by making a texture into a rectangular shape, it becomes easy to arrange each texture in an integrated texture, and there exists an advantage which becomes easy to manage. In this aspect, the opposing vertex coordinates of the rectangular shape correspond to attribute information that indirectly specifies the range on the storage unit in which the texture is stored.
Depending on the graphics library that handles textures, all textures may be represented in a texture-specific coordinate system with a value of 0 to 1. In such a case, the integrated texture is divided into square areas, and each texture is assigned to each square area. You may do it. In this way, there is an advantage that texture arrangement and management become easier.

In the image display system of the present invention,
The texture data storage unit stores related data that gives the vertex coordinates for each of the plurality of types of textures,
The display control unit may identify the range with reference to the related data.
In this aspect, when the attribute information specifies which texture is to be applied to the polygon, the relevant texture range can be specified by referring to the related data corresponding to the texture, and the texture data Can be read. That is, this is an aspect in which the range of each texture in the integrated texture is specified via the related data. As described above, if the range is specified through the related data, when the texture is used with a plurality of polygons, the range can be easily managed. For example, even when the position and size of the texture are changed in the integrated texture, it is possible to collectively change the texture application mode for a plurality of polygons by correcting the related data.

In the image display system of the present invention,
The attribute information further includes pattern information for specifying a pattern to be pasted by repeatedly arranging the texture,
The display control unit may arrange and paste the textures based on the pattern information.
By doing so, it is possible to easily realize a repetitive pattern as shown in the textures B and C of FIG.

The present invention can be applied to display various images. For example,
The polygon constitutes a three-dimensional model of the feature,
The three-dimensional model is managed by dividing into a mesh of a predetermined size set on the ground surface according to the position of the feature,
The integrated texture data is configured for each mesh using a texture applied to polygons included in a three-dimensional model in the mesh,
The display control unit may perform the pasting by selecting the integrated texture according to the position of the feature corresponding to the polygon.
By doing so, the present invention can be utilized for displaying a three-dimensional map. The three-dimensional map includes a large number of three-dimensional models, and since many textures are used in order to improve the reality, the utility of the present invention is particularly high. By using the present invention for displaying a three-dimensional map, the processing load required for display can be greatly reduced.
Moreover, in the said aspect, an integrated texture is produced | generated for every mesh which is a management unit of map data. By doing so, there is an advantage that the management unit of the integrated texture and the three-dimensional model is unified, and the integrated texture can be easily used.

The image display system of the present invention further includes:
A polygon identifying unit for identifying a polygon used for displaying an image;
An integrated texture data generating unit that extracts the texture corresponding to the specified polygon from the texture data storage unit, and generates the integrated texture data by arranging the extracted textures so as not to overlap. It may be a thing.
By doing so, it is possible to generate an integrated texture from a plurality of textures. The integrated texture may be generated dynamically at the time of image display, or may be generated in advance.
In this aspect, the integrated texture data generation unit, the texture data storage unit for displaying the image, the input unit, the display control unit, and the like may be configured separately. For example, the integrated texture data generated in advance in the above-described mode is provided to a terminal for image display including a texture data storage unit, an input unit, and a display control unit via communication or a medium. The integrated texture data can be used to display an image. There may be a plurality of terminals in this case. According to this aspect, the generated integrated texture data can be shared by many terminals, and convenience is improved.
The arrangement of textures when generating the integrated texture can be determined by various methods. For example, when all the textures are represented by unique relative coordinates of values 0 to 1, the integrated texture may be divided into square areas in advance, and a texture may be sequentially assigned to each area.

In the present invention, it is not always necessary to include all of the various features described above, and some of the features may be omitted or combined as appropriate.
In addition, the present invention may be configured as an image display method for displaying an image by a computer, or may be configured as a computer program for causing a computer to execute such display. Further, an integrated texture data generation method for generating integrated texture data used for image display using an individual texture database applied to each polygon may be configured, or an integrated texture data generation method for causing a computer to perform this. It can also be configured as a computer program for that purpose. Furthermore, it may be configured as a CD-R, DVD, or other computer-readable recording medium on which the above-described computer program is recorded.

It is explanatory drawing which shows the example of application of the texture in a prior art. It is explanatory drawing which shows the example of application of a texture. It is explanatory drawing which shows the structure of a route guidance system. It is explanatory drawing which shows the data structure of a map database. It is a flowchart of a map display process. It is a flowchart of a texture sticking process. It is explanatory drawing which shows the structure of an integrated texture data generation apparatus. It is a flowchart of an integrated texture generation process.

  An embodiment of the image display system of the present invention will be described by taking as an example a case where it is configured as a route guidance system. The route guidance system is a device that guides a route from a departure place designated by a user to a destination while displaying a three-dimensional map. The image display system is incorporated as a part that realizes the function of displaying this three-dimensional map.

A. How to apply texture:
In this embodiment, a texture is attached to each polygon of the three-dimensional model, and a highly realistic three-dimensional map is displayed. Before showing the configuration of the route guidance system, a method of using this texture will be described.
FIG. 2 is an explanatory diagram illustrating an application example of texture. An example of pasting a texture on a 3D model of a building was shown. A texture A portion representing the exterior of the roof is affixed to the upper surface of the building, and a texture B portion and a C portion representing windows are arranged and affixed to the front and side surfaces, respectively.
In this embodiment, as shown in the lower right of the figure, an integrated texture in which texture A part, B part, and C part are arranged is prepared. And about the upper surface, only the texture A part in an integrated texture is used as a sticking object. For the front and side surfaces, only the texture B and C portions in the integrated texture are repeatedly used as the objects to be pasted. In other words, in this embodiment, the same appearance as when the textures A to C are individually used is realized by using different integrated textures including the texture parts.
When preparing the textures A to C as individual texture data, it is necessary to read and process each texture data from a non-volatile memory such as a hard disk when pasting. On the other hand, in the present embodiment, if the integrated texture is read once, the textures A to C can be pasted, so the processing load of reading can be reduced in the texture pasting process. . In a three-dimensional map, a large number of textures are used for a large number of three-dimensional models, so that the effect of reducing the load of the entire display processing by reducing the processing load of reading is greatly increased.

B. System configuration:
FIG. 3 is an explanatory diagram showing the configuration of the route guidance system. The route guidance system 100 of an Example showed the example comprised as a car navigation apparatus. The route guidance system 100 may be configured using a smartphone, a tablet, or other portable terminals. Moreover, although the route guidance system 100 of an Example showed the example which operate | moves stand-alone, it is good also as a structure which connected the server and the terminal device with the network.

  The route guidance system 100 is configured as a computer including a CPU, GPU, RAM, ROM, hard disk, and the like, and includes each functional block shown in the figure. Each functional block is configured by installing hardware provided in the route guidance system 100 such as a hard disk and a sensor and software for realizing each function. These functional blocks can also be configured in hardware by an electronic circuit or the like.

The route guidance system 100 stores a map database 110 used for route search, map display, and the like in a hard disk. The map database 110 includes each database shown in the figure. The line database 111 stores a three-dimensional model representing the shape of a linear object such as a road or a track in a three-dimensional map. The polygon database 112 stores a three-dimensional model representing a three-dimensional shape of a three-dimensional object such as a building.
The texture group database 113 stores data that associates each polygon of the three-dimensional model with the texture applied thereto. The texture database 114 stores texture image data to be attached to each polygon. The integrated texture described in FIG. 2 is stored here, and the texture group database 113 specifies which part of the integrated texture is applied to each polygon by specifying the coordinates of the integrated texture. specify. The structures of the texture group database 113 and the texture database 114 will be specifically described later.
The character database 115 stores character data displayed in the three-dimensional map. The network database 116 stores data representing roads in a network composed of links and nodes as route search data.

  In this embodiment, the map database 110 is managed in units of meshes. That is, the ground surface is divided into rectangular meshes of a predetermined size, the area is divided for each mesh, and line data, polygon data, character data, etc. corresponding to the features in the area are stored. Similarly, the texture database 114 also stores each texture applied to the polygons in each mesh by generating an integrated texture for each mesh. By doing so, there is an advantage that when displaying a map, data can be handled in units of meshes including textures, and the management and use of the data becomes easy.

The command input unit 101 inputs a command designated by the user. Examples of the command include a route search starting point, a destination designation, and a map display mode designation.
The GPS 102 detects the current position of the route guidance system 100 using a GPS (Global Positioning Sensor) or the like.
The route search unit 103 uses the network database 116 to search for a route from the designated departure point to the destination. Various methods such as the Dijkstra method can be applied to the route search.
The display control unit 120 displays a three-dimensional map. First, the object placement unit 121 places the 3D models stored in the line database 111 and the polygon database 112 in the virtual 3D space. The texture pasting unit 122 applies the texture stored in the texture database 114 to each polygon. In this application, as shown in FIG. 2, the integrated texture is read from the texture database 114 and a part thereof is pasted for each polygon. The projection unit 123 perspectively projects the object on which the texture has been pasted according to the specified viewpoint position and line-of-sight direction, and generates a projection image for display. The character display unit 124 superimposes and displays characters on the generated projection image.
Of the route guidance system 100, the part related to the display of the three-dimensional map, that is, the map database 110 and the display control unit 120 have a configuration corresponding to the image display system of the present invention.

FIG. 4 is an explanatory diagram showing the data structure of the map database. The structure of the polygon database 112, the texture group database 113, and the texture database 114 was illustrated.
The polygon database 113 stores a three-dimensional model such as a building. “ID” is identification information of each polygon constituting each three-dimensional model. “Shape” stores three-dimensional coordinates such as the apexes AP1 and AP2 of polygons constituting the three-dimensional model. “Texture” is identification information for designating a texture to be attached to each polygon. In this embodiment, the texture in the texture group database 113 is designated instead of designating the texture directly. The attribute stores various information regarding the polygon. For example, information such as the name, type, height, and color of a building.

The texture database 114 stores integrated texture image data.
Identification information is attached to the integrated texture, such as TID1 and TID2. As shown in the figure, the integrated texture is a texture in which a plurality of texture portions A, B, C, and the like are arranged. In the example of the figure, an example in which three textures are arranged is shown, but the number, shape, and size of the textures included in the integrated texture can be arbitrarily set within a range where the textures do not overlap each other.
In this embodiment, the map database 110 is maintained in units of meshes obtained by dividing the ground by a predetermined range. Therefore, the integrated texture is also generated so as to include the texture applied to the polygons in the mesh in units of each mesh. If the same texture is used for objects residing in different meshes, this texture will be redundantly included in the integrated texture corresponding to each mesh. Although such overlapping parts occur, maintaining the integrated texture in mesh units allows the object and texture to be handled in mesh units when displaying a map, which has the advantage of facilitating the management and use of data. is there.
However, it is not an essential requirement to generate the integrated texture in units of meshes, and various other units can be selected as the unit for preparing the integrated texture.

The texture group database 113 stores related data that associates the polygon database 112 and the texture database 114. “GID” is identification information of related data. In the polygon database 112, polygon data can be associated with related data by specifying this GID. In the example shown in the figure, since PID1 and PID2 data stored in the polygon database 112 both store GID1 in “texture”, both of these polygons are related data as GID1 in the texture group database 113. Will be associated. This makes it possible to easily associate a plurality of texture data with polygon data.
“TID” in the texture group database 113 is identification information of the texture database 114. By designating the TID, the texture group database 113 and the texture database 114 can be associated with each other. In the example shown in the figure, since “TID1” is stored as “TID” in the related data to which GID1 is attached, this related data is associated with the texture data TID1 in the texture database 114.
Pmin and Pmax in the texture group database 113 are coordinate data for designating the range of the texture to be pasted to the polygon in the integrated texture. Pmin represents the lower left vertex coordinate of the texture range, and Pmax represents the upper right vertex coordinate. In the illustrated example, P1 and P2 are designated as Pmin and Pmax, respectively. If these P1 and P2 are positions shown in the coordinate system in the texture TID1, the texture A portion is designated as a range to be pasted by these two points. Similarly, when the texture B portion is designated, the lower left vertex may be designated as Pmin, and the upper right vertex may be designated as Pmax.
“Polygon” in the texture group database 113 is information for designating polygon data so that the polygon database 112 can be referred to from the texture group data 113. In the example shown in the figure, PID1 and PID2 of the polygon database 112 are associated with GID1 of the texture database. Therefore, “polygon” stores PID1 and PID2 indicating reverse correspondence.

With the above data structure, each polygon data in the polygon database 112 can be associated with a range in the integrated texture in the texture database 114 via the texture group database 113. In the present embodiment, since the association is performed indirectly via the texture group database 113, if the integrated texture in the texture database 114 is updated, the texture group database 113 can be modified and There is an advantage that the correspondence can be easily changed in a lump.
The correspondence between polygons and textures can be made by omitting the texture group database 113 and storing the identification information TID1, TID2, etc. of the texture database 114 and the vertex coordinates Pmin, Pmax directly in each polygon of the polygon database 112. Good.

C. Map display processing:
FIG. 5 is a flowchart of the map display process. This is a process executed when displaying a three-dimensional map in the process of guiding the route to the user. This process is a process mainly executed by the display control unit 120 shown in FIG. 3, and is a process executed by the CPU and GPU of the route guidance system 100 in terms of hardware.

When the process is started, the route guidance system 100 sets a viewpoint, a line-of-sight direction, a display range, and the like (step S10). These parameters can be set based on the current position of the route guidance system 100, the searched route, and the like. Moreover, you may set by the command from a user.
The route guidance system 100 reads map data within the set display range (step S12), and places a three-dimensional model in the virtual three-dimensional space (step S14). Then, a texture pasting process is performed on the polygon (step S16). This process is a process of applying a part of the integrated texture to each polygon as shown in FIG. Details of the processing will be described later.
When the pasting of the texture is completed, the route guidance system 100 performs perspective projection from the designated viewpoint and line-of-sight direction (step S18), and generates a projection drawing. Instead of perspective projection, a projection method such as parallel projection may be used. And the route guidance system 100 displays a character in a projection map (step S20), and completes a map display process.
The above map display processing is repeatedly executed while changing the viewpoint, line-of-sight direction, etc., until reaching the destination in route guidance.

FIG. 6 is a flowchart of the texture pasting process. This is processing corresponding to step S16 of the map display processing (FIG. 5).
The route guidance system 100 first reads integrated texture data corresponding to the display range of the map (step S30). Since the integrated texture data is generated in units of meshes, it is sufficient to read one integrated texture data when the display range is within a single mesh. When the display range extends over a plurality of meshes, a plurality of integrated texture data is read.

Next, the route guidance system 100 sets a texture part (step 32). This is a process for specifying a portion to be applied to a polygon to be processed in the integrated texture. This is not an image process such as cutting out a texture portion from the integrated texture, but a process only for specifying the range.
In this embodiment, the texture portion to be pasted is specified by the coordinate values of the lower left vertex Pmin (Umin, Vmin) and the upper right vertex Pmax (Umax, Vmax) by the u, v coordinate system set for the integrated texture. The This coordinate value is obtained by referring to the texture group database 113.

Then, the route guidance system 100 attaches a texture to the corresponding polygon (step S34). An example of attaching a texture in the figure is shown. As shown in the figure, only the rectangular range specified by the vertices Pmin and Pmax in the integrated texture is pasted. Instead of applying the image processing such as cutting out the range from the integrated texture, only the range is applied when the integrated texture is pasted. In the example of the figure, an example in which the objects are pasted to the polygons 1 and 2 of the buildings 1 and 2 is shown, but the same range can be applied to a plurality of polygons of a plurality of buildings. The arrangement can be arbitrarily set depending on the shape of the polygon.
The route guidance system 100 repeatedly executes the above processing for all textures (step S36).

The above-described texture pasting will be described in a little more detail. In a graphics library used in 3D graphics, a texture image is defined by a square shape consisting of normalized coordinates of values 0 to 1, and its four vertices (0, 0), (0, 1), ( In many cases, the pasting state of the texture is specified by designating which point of the polygon corresponds to (1, 0) and (1, 1). In the present embodiment, the range specified by the vertices Pmin and Pmax is defined in the coordinate system of the integrated texture at the specified time, and thus does not have the above-described normalized square shape. Therefore, in the pasting process in step S34, the four vertices (0, 0), (0, 1), (1, 0), and (1, 1) described above correspond to the four vertices in the specified range. The coordinate transformation is performed by the following formula.
umod = Umin + (u−Umin) / (Umax−Umin);
vmod = Vmin + (v−Vmin) / (Vmax−Vmin);
Here, u and v represent the four vertices (0,0), (0,1), (1,0), (1,1) of the normalized square when applying the texture and the inside thereof. These are coordinate values in the relative coordinate system within the range specified by the coordinate system, that is, the ranges specified by the vertices Pmin and Pmax, and umod and vmod are values obtained by converting them into the coordinates of the integrated texture. By performing such coordinate conversion, within the graphics library, four vertexes (0, 0), (0, 1), (1, 0) are within the range specified by the vertices Pmin and Pmax in the integrated texture. , (1,1) is treated as a normalized square shape, and other areas are treated as invalid areas in the texture pasting process. As a result, only a part of the integrated texture is used. The pasting can be performed.

According to the route guidance system 100 of the embodiment described above, and by extension, the image display system incorporated therein, map display can be performed using the integrated texture. Therefore, when the map is displayed, as long as the integrated texture is read out, the texture can be pasted without reading a large number of textures. For this reason, according to the embodiment, it is possible to reduce the processing load required for texture reading, and consequently the processing load for map display.
In particular, in this embodiment, a hardware configuration including a CPU and a GPU is adopted. In the hardware having such a configuration, the GPU executes processing of texture reading and drawing in accordance with a drawing command issued from the CPU. In this embodiment, since the integrated texture is used, regarding the texture processing, the GPU only needs to issue a command once to the GPU, and the GPU executes the pasting process by properly using the necessary internal parts. Can do. Therefore, according to the present embodiment, the number of command issuances can be reduced, and the processing time can be reduced.
In general, the GPU has an upper limit on the number of textures that can be managed. However, in this embodiment, since the integrated texture is used, the total number of textures can be reduced within a range not exceeding the upper limit. Therefore, according to the present embodiment, it is possible to draw using various textures efficiently.

  Next, a route guidance system as a second embodiment will be described. The route guidance system according to the second embodiment includes an integrated texture data generation device 200 that automatically generates an integrated texture. The configuration for displaying the three-dimensional map using the integrated texture and the contents of the map display processing are the same as in the first embodiment. In the first embodiment, the integrated texture includes a case where the integrated texture is generated by an operator's manual work or the like, but the second embodiment is different in that it is automatically generated.

D. System configuration of the second embodiment:
FIG. 7 is an explanatory diagram showing a configuration of the integrated texture data generation apparatus. The integrated texture data generation apparatus 200 is configured by installing a computer program for realizing each function illustrated in the computer PC. Not only a configuration as a stand-alone operating device but also a configuration in which a server and a computer are connected via a network is possible. In addition, each functional block in the figure may be configured in hardware as well as in software.

  The original map database 210 is used for generating integrated texture data. The polygon database 211 stores polygon data constituting a three-dimensional model such as a building for displaying a three-dimensional map. The contents are the same as those of the polygon database 112 (see FIG. 3) described in the first embodiment. The individual texture database 212 is a database that stores image data of textures attached to each polygon. The integrated texture data is generated by arranging the textures stored in the individual texture database 212.

The command input unit 202 inputs various commands from the operator. Examples of the command include designation of a mesh to be processed for generating integrated texture data.
The integrated texture generation unit 220 arranges the texture data stored in the individual texture database 212 and generates an integrated texture.
The texture group database generation unit 222 generates related data (see FIG. 4) that associates the integrated texture with the polygon.
The polygon database correction unit 224 corrects the polygon data based on the generated related data. That is, in the polygon data before correction, the content of the portion designated to paste the texture data stored in the individual texture database 212 is modified so as to designate related data corresponding to the texture data. It is. By doing so, it is possible to associate polygons with textures via the texture group database 113 as shown in FIG.
The data management unit 226 stores the integrated texture and related data generated as described above as the map database 110. The generated map database 110 is distributed to the user via the network NE and the recording medium 228.

  As described above, in the second embodiment, the integrated texture data generation device 200 and the device that displays the map using the integrated texture data generation device 200 are shown as separate components. Show. Each function of the integrated texture data generation apparatus 200 can be configured as an integrated system by being incorporated in the route guidance system 100 shown in the first embodiment.

E. Integrated texture generation processing:
FIG. 8 is a flowchart of the integrated texture generation process. This process is executed by the integrated texture generation unit 220, the texture group database generation unit 222, and the polygon database correction unit 224 of the integrated texture data generation apparatus 200. In terms of hardware, the process executed by the CPU of the integrated texture data generation apparatus 200 It is.

First, the integrated texture data generation device 200 selects a target mesh to be processed (step S40). This is because the integrated texture is generated in units of meshes as already described. The target mesh may be designated by the operator, or may be automatically selected from unprocessed meshes.
The integrated texture data generation apparatus 200 identifies a polygon in the target mesh and reads an individual texture corresponding to the polygon (step S42). There is no need to read the polygon itself because it does not generate a projection.

Next, the integrated texture data generation device 200 arranges individual textures and generates an integrated texture (step S44). The arrangement method is schematically shown in the figure. Textures A to C shown on the left are individual textures. This is arranged in the integrated texture as shown in the figure. The arrangement method may be any position as long as the individual textures do not overlap each other.
When the individual textures A to C are defined by squares composed of normalized coordinate systems (0, 0) to (1.1), respectively, the integrated texture is divided into square areas of a certain size in advance. Alternatively, the individual textures A to C can be sequentially assigned to the respective areas.
The individual textures A to C are not necessarily square, and can have any shape. By doing so, an integrated texture can be generated while preventing a decrease in resolution of each individual texture. However, for convenience of arrangement, the individual textures A to C are preferably rectangular.

When the generation of the integrated texture is completed, the integrated texture data generation apparatus 200 generates a texture group database based on the relationship between the polygons and the individual textures (step S46). As shown in FIG. 4, the relevant data may be generated by specifying and storing the coordinates of the vertices Pmin and Pmax of the individual texture corresponding to the polygon.
When the related data can be generated in this way, the integrated texture data generation apparatus 200 associates the texture group database with the polygon database (step S48). That is, as shown in FIG. 4, information for specifying related data is stored as data for specifying the texture to be pasted in the polygon database.
When the above processing is completed, the integrated texture data generation apparatus 200 stores each database (step S50) and ends the integrated texture generation processing.

  According to the second embodiment, since the integrated texture can be automatically generated, it is possible to reduce not only the processing for displaying the map but also the preprocessing load for that purpose.

The embodiment of the present invention has been described above. The various features described in the embodiments are not necessarily all provided, and can be configured by omitting or combining some of them as appropriate.
In the embodiment, an example of a system for displaying a three-dimensional map has been shown. However, the present invention can be used not only for displaying a three-dimensional map but also for various systems for displaying an image using a plurality of textures. It is.
In the embodiment, the configuration including the CPU and the GPU is exemplified, but the present invention is also applicable to a configuration including only the CPU.

  The present invention can be used to display images by pasting a plurality of types of textures to a plurality of polygons.

DESCRIPTION OF SYMBOLS 100 ... Route guidance system 101 ... Command input part 102 ... GPS
DESCRIPTION OF SYMBOLS 103 ... Route search 110 ... Map database 111 ... Line database 112 ... Polygon database 113 ... Texture group database 114 ... Texture database 115 ... Character database 116 ... Network database 120 ... Display control part 121 ... Object arrangement part 122 ... Texture sticking part 123 ... Projection unit 124 ... Character display unit 200 ... Integrated texture data generation device 202 ... Command input unit 210 ... Original map database 211 ... Polygon database 212 ... Individual texture database 220 ... Integrated texture generation unit 222 ... Texture group database generation unit 224 ... Polygon database Correction unit 226 ... Data management unit 228 ... Recording medium

Claims (8)

An image display system that displays images by pasting multiple types of textures to multiple polygons,
A texture data storage unit for storing integrated texture data representing images arranged at arbitrary positions so as not to overlap the plurality of types of textures;
An input unit for reading the polygon and attribute information for designating which of the plurality of types of textures are pasted on each polygon;
A display control unit that displays an image by pasting the texture on the polygon according to the attribute information;
The display control unit
The integrated texture data is read from the texture data storage unit, stored in the storage unit,
Based on the attribute information, specify a range on the storage unit in which the specified type of texture is stored,
An image display system that performs the pasting using data within the specified range of the integrated texture data. The image display system according to claim 1,
Each of the plurality of types of textures has a rectangular shape,
The display control unit is an image display system in which a range in which the texture is stored is specified by vertex coordinates of the rectangular shape facing each other. The image display system according to claim 1 or 2,
The texture data storage unit stores related data that gives the vertex coordinates for each of the plurality of types of textures,
The display control unit is an image display system that specifies the range by referring to the related data. The image display system according to any one of claims 1 to 3,
The attribute information further includes pattern information for specifying a pattern to be pasted by repeatedly arranging the texture,
The display control unit is an image display system in which the texture is arranged and pasted based on the pattern information. The image display system according to any one of claims 1 to 4,
The polygon constitutes a three-dimensional model of the feature,
The three-dimensional model is managed by dividing into a mesh of a predetermined size set on the ground surface according to the position of the feature,
The integrated texture data is configured for each mesh using a texture applied to polygons included in a three-dimensional model in the mesh,
The image display system in which the display control unit performs the pasting by selecting the integrated texture according to the position of the feature corresponding to the polygon. The image display system according to claim 1, further comprising:
A polygon identifying unit for identifying a polygon used for displaying an image;
An integrated texture data generating unit that extracts the texture corresponding to the specified polygon from the texture data storage unit, and generates the integrated texture data by arranging the extracted textures so as not to overlap. Image display system. An image display method for displaying an image by pasting a plurality of types of textures to a plurality of polygons,
As a step executed by a computer storing integrated texture data representing an image arranged at an arbitrary position so as not to overlap the plurality of types of textures in a texture data storage unit,
(A) reading the polygon and attribute information for designating which of the plurality of types of textures are to be pasted on each polygon;
(B) pasting the texture on the polygon according to the attribute information and displaying an image;
The step (b)
The integrated texture data is read from the texture data storage unit, stored in the storage unit,
Based on the attribute information, specify a range on the storage unit in which the specified type of texture is stored,
An image display method for performing the pasting using data within the specified range of the integrated texture data. A computer program for displaying images by pasting multiple types of textures on multiple polygons,
In a computer that stores integrated texture data representing an image arranged at an arbitrary position so that the plurality of types of textures do not overlap each other in a texture data storage unit,
A function of reading the polygon and attribute information for designating which of the plurality of types of textures are pasted to each polygon;
In accordance with the attribute information, to realize a display function to display the image by pasting the texture to the polygon,
As the display function,
The integrated texture data is read from the texture data storage unit, stored in the storage unit,
Based on the attribute information, specify a range on the storage unit in which the specified type of texture is stored,
A computer program that realizes the function of performing the pasting by using data within the specified range of the integrated texture data.

Images