JP2005316702A - Three-dimensional view display device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a three-dimensional view display device capable of displaying a building ceiling having a complicated polygonal shape by use of a 3D graphics chip. <P>SOLUTION: This three-dimensional view display device has: a map data storage means 31 storing an attribute including at least one of a color, a pattern and a texture of the building ceiling and height information of a building, and a bottom shape of the building; a building 3D model generation means 32 generating a building 3D model shape showing coordinates of the building in a three-dimensional space by use of the height information and the bottom shape of the building stored in the map data storage means; and a 3D drawing means performing drawing of the front face of a building wall face constituting a building 3D model generated by the building 3D model generation means, drawing by at least one of the color, the pattern and the texture of the building ceiling stored in the map data storage means, of the rear face of the building wall face constituting the building 3D model generated by the building 3D model generation means, and hidden surface removal, by use of the three-dimensional graphics chip, and drawing a three-dimensional shape of the building. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a three-dimensional landscape display device for stereoscopic display of a city landscape, which is used in a vehicle navigation system, a geographic information system (GIS), and the like.

In a conventional three-dimensional landscape display device typified by a vehicle navigation system, the bottom shape of a building of map data (hereinafter, sometimes referred to as a bottom polygon shape or a polygon shape of a bottom polygon) when displaying a three-dimensional map. From the height of the building (sometimes expressed by the number of floors), the building was drawn three-dimensionally in a way that the polygon, which is the bottom shape of the building, is set up vertically by the height of the building (for example, , See Patent Document 1).
In addition, 2D (2D) graphics chips used in conventional 3D landscape display devices are good at drawing characters and polygons on a flat surface, but they do hidden surface removal such as 3D display of buildings. There was no function to do. Therefore, the conventional 3D landscape display apparatus first sorts the buildings according to the distance from the viewpoint, and draws in order from the building at the back of the screen. In the drawing of each building, the hidden surface was erased by drawing in order from the back wall as viewed from the viewpoint, and finally drawing the ceiling surface in a polygon.

Japanese Patent Laid-Open No. 2002-298162 (25th paragraph, FIG. 2)

  In the future, 3D landscape display devices represented by vehicle navigation systems are increasingly required to display faster and more realistically, and conventional graphics chips do not have a hidden surface removal function. Thus, it is necessary to perform hidden surface removal by a CPU (Central Processing Unit), and it has not been possible to answer such a demand for high speed. Therefore, it is expected that a 3D (3D) graphics chip used in a personal computer or the like will be used in a 3D landscape display device.

  The 3D graphics chip can perform hidden surface removal by the chip by writing the depth value of each drawing pixel in a buffer that stores a depth value, usually called a Z buffer. For drawing with a 3D graphics chip, a 3D drawing library such as Direct3D (Direct3D: 3D Drawing Library: Reference = DirectX5 Official Manual, Microsoft Co., ASCII Publishing Bureau, 1998) is usually used on a personal computer. And draw. Also, in an embedded system such as a 3D landscape display device, an original 3D drawing library provided by a chip manufacturer is often used. These 3D drawing libraries are all based on drawing with a triangle because of the principle of the 3D graphics chip.

  Therefore, in the building drawing in the three-dimensional landscape display, the building wall surface is usually a quadrangular shape, so that the hidden surface can be easily drawn by using the 3D graphics chip as two triangles. Even when the map plane portion (the bottom portion of the building) has a complex polygonal shape such as a pentagon, for example, polygon drawing may be performed using the function of the conventional 2D graphics chip. However, when the building ceiling portion has a complicated polygonal shape such as a pentagon, for example, there is a problem that hidden surface erasure drawing cannot be performed by the 3D graphics chip.

  The present invention has been made in order to solve the above-described problems of the prior art, and uses a 3D graphics chip that can draw only a triangle but can perform hidden surface removal, for example, a complex shape such as a pentagon. An object of the present invention is to provide a three-dimensional landscape display device capable of displaying a building ceiling having a polygonal shape.

  The three-dimensional landscape display device according to the present invention includes a map data storage means for storing an attribute including at least one of a building ceiling color, pattern and texture and building height information, and a bottom shape of the building, Using a building 3D model generation unit that generates a building 3D model shape indicating coordinates in a three-dimensional space of the building using the bottom shape and height information of the building stored in the map data storage unit, and a three-dimensional graphics chip The drawing of the surface of the building wall constituting the building 3D model generated by the building 3D model generating means, and the map data storage of the back surface of the building wall forming the building 3D model generated by the building 3D model generating means Draws at least one of the color, pattern and texture of the building ceiling stored in the means and removes the hidden surface to draw the 3D shape of the building A 3D rendering unit which is obtained by a display means for displaying the three-dimensional shape of the drawn by 3D rendering unit building.

  Further, the map data storage means for storing the attribute including the height information of the building and the bottom shape of the building, and the bottom shape and height information of the building stored in the map data storage means, the three-dimensional building Using a building 3D model generating means for generating a building 3D model shape indicating coordinates in space, a building ceiling triangulation means for dividing the bottom shape of the building into triangles as a building ceiling polygon, and a three-dimensional graphics chip The surface of the building wall constituting the building 3D model generated by the building 3D model generation means and the ceiling divided into triangles by the building ceiling triangulation means are drawn and the hidden surface is erased, and the three-dimensional shape of the building is obtained. 3D drawing means for drawing, and display means for displaying the three-dimensional shape of the building drawn by the 3D drawing means.

  Even when the building ceiling is composed of a complex polygon such as a pentagon, for example, by drawing the back of the building wall with a ceiling color or ceiling pattern or ceiling texture, It can be displayed as if it were drawing the ceiling.

  In addition, even when the building ceiling is composed of a complex polygon such as a pentagon, for example, it can be drawn using a 3D graphics chip that can draw only triangles by dividing the triangle into triangles. As a result, 3D display using a more advanced and realistic decoration function of a 3D graphics chip, such as lighting on a building ceiling or pasting an arbitrary texture, becomes possible.

Embodiment 1 FIG.
Hereinafter, a case where the present invention is applied to a vehicle navigation system will be described.
FIG. 1 is a schematic configuration diagram showing a hardware configuration of a vehicle navigation system to which a three-dimensional landscape display device according to Embodiment 1 of the present invention is applied. As shown in FIG. 1, the vehicle navigation system includes a GPS receiver 11 that receives GPS data transmitted from a GPS (Global Positioning System) satellite, and a map display based on the GPS data received by the GPS receiver 11. A microprocessor 15 that performs normal navigation processing such as route guidance and route search, a graphics chip 18 that writes drawing contents such as a map display in the frame buffer 19 according to an operation program under the instruction of the microprocessor 15, And a display monitor 20 for displaying the drawing contents of the frame buffer 19.

Furthermore, a ROM 12 that stores an operation program of the microprocessor 15, a RAM 13 that temporarily stores various data when the microprocessor 15 executes processing, and a battery backup that stores backup data used by the operation program A permanent storage unit 14 such as a SRAM, a DRAM, or a writable flash ROM, an external storage device 16 such as a CD-ROM, a DVD-ROM, or a hard disk, and an external storage interface unit 17 that controls the external storage device 16. ing.
Note that the program in the ROM 12 may be expanded in the RAM 13 at startup.
Conventionally, a graphics chip that does not have a hidden surface removal function has been used as the graphics chip 18, but in this embodiment, only a triangle can be drawn with a graphics chip used in a personal computer or the like, but hidden surface removal can be performed. A 3D graphics chip is used.

  FIG. 2 is a configuration diagram showing a functional configuration of the vehicle navigation system according to the first embodiment of the present invention. The processing of these functions is executed by an operation program stored in the ROM 12 of FIG. The user interface unit 22 displays an operation menu and a destination setting menu. The own vehicle position detection unit 23 estimates the current position of the vehicle from the GPS receiver 11 of FIG. 1 and the map data stored in the external storage device 16. The route search unit 24 calculates a guide route from the current position of the vehicle to the destination. The route guide unit 25 provides route guidance to the driver by voice and an intersection guide map according to the searched guide route. A map display unit (three-dimensional landscape display unit) 26 that displays a map displays the position of the vehicle on the map. The map display unit 26 includes a building three-dimensional display unit 27 that three-dimensionally displays a building when the map is three-dimensionally displayed. The common processing unit 28 performs processing common to each unit, such as management of common data such as paths and management of various common libraries such as a drawing library.

FIG. 3 is a configuration diagram illustrating a configuration of the building three-dimensional display unit. The map data storage means 31 stores the bottom shape of the building (bottom surface polygon shape) and its attributes (including at least the height information of the building). As will be described in detail later, the building 3D model generation unit 32 uses the bottom shape of the building by the height of the building from the polygonal shape and building attributes of the bottom polygon stored in the map data storage unit 31. A 3D model (three-dimensional shape) indicating coordinates in a three-dimensional space of a building is generated by a method in which a certain polygon is set up vertically.
The 3D drawing means 35 draws the surface of the building wall surface constituting the building 3D model using a 3D graphics chip. At this time, a texture indicating a building window or the like is pasted on the wall surface, or the texture is drawn on the wall surface by overwriting the window or the like. Furthermore, the 3D drawing means 35 draws the back surface of the building wall surface constituting the building 3D model using a 3D graphics chip. At this time, the back surface of the building wall is drawn with the color of the building ceiling, the pattern of the building ceiling, or the texture of the ceiling.

Since the 3D drawing means 35 draws using a 3D graphics chip, the polygon cannot be drawn and only the triangle can be drawn, but the wall surface of the building is composed of a quadrangle. It can be easily drawn as two triangles. In the following description, the case where the building 3D model generation unit 32 stores the quadrangular shape of the wall surface of the building by dividing it into three shapes will be described, but the present invention is not limited to this.
If the ceiling of the building has a complex polygonal shape such as a pentagon, for example, it could not be drawn with a 3D graphics chip, but in this embodiment, the color of the building ceiling By drawing with the building ceiling pattern and ceiling texture, as shown in FIG. 4, the screen display is similar to drawing the ceiling without drawing the ceiling of the building separately. An effect can be obtained. That is, the building ceiling can be displayed.

  For wall drawing, a function called 3D graphics culling may be used. As shown in FIG. 5, the culling function is a surface that becomes non-displayed in the counterclockwise vertex order after the coordinate conversion into the screen coordinates by setting to 3D graphics, or the surface that becomes the clockwise vertex order. It is a function to hide. For example, in the above-described Direct3D, which is a representative 3D graphics library, culling is set by setting the first argument to D3DRS_CULLMODE with the IDirect3DDevice8 :: SetRenderState function. The second argument is used to set whether the clockwise rotation is hidden (D3DCULL_CW), the counterclockwise rotation is not displayed (D3DCULL_CCW), or whether it is displayed in either direction (D3DCULL_NONE). Using this culling function, the building wall surface is described with a clockwise vertex description, and when drawing on the front side, it is drawn with the culling setting to hide counterclockwise, and when drawing on the back side, the culling setting is set to hide clockwise. By drawing with, you can draw the front and back. Another method is to describe the surface of the building wall with a clockwise vertex description, describe the back of the building wall with a counterclockwise vertex description, and draw with a culling setting that hides the counterclockwise direction. May be.

  Here, the operation of the building 3D model generation means 32 will be described. For example, the bottom polygon shape of the building as shown in FIG. 6 is stored in the map data storage means 31 together with the height information of the building. In order to generate a building 3D model from the bottom polygon shape of this building, as shown in FIGS. 7 and 8, first, the coordinates in the three-dimensional space of the wall with the base AB standing vertically by the height of the building are shown. 3D model is generated, and a building 3D model is generated by generating wall surfaces in order of the base BC, the base CD, the base DE, and the base EF. At this time, the triangle primitive is described clockwise. For the three-dimensional coordinates, a right-handed coordinate system or a left-handed coordinate system as shown in FIGS. 9A and 9B is used. At this time, the y coordinate of the wall surface indicates the height of the building. Further, as shown in FIG. 10, the triangle primitive has a texture uv coordinate. In 3D graphics, the texture can be repeated by setting the texture coordinates to a value greater than one. For example, if you want to repeat the texture three times, you can set (u, v) = (3.0, 3.0).

  Next, the operation of the 3D drawing unit 35 will be described. First, drawing of the surface of a building wall surface will be described. On the surface of the building wall, the description (triangle primitive) of the building 3D model shown in FIG. 8 is drawn in 3D by counterclockwise culling with the texture shown in FIG. The program description of this operation is as shown in FIG. 11, and looks like FIG. 12 by counterclockwise culling. In the 3D drawing, the 3D model can be drawn from a certain viewpoint, and only the surface of the building wall surface viewed from this viewpoint is displayed. If the vertex description of the 3D model is made counterclockwise, the same display can be obtained by 3D drawing by clockwise culling.

  Next, drawing of the back surface of a building wall surface will be described. On the back surface of the building wall, the description (triangular primitive) of the 3D model at the bottom of FIG. 8 is drawn in 3D by clockwise culling with the ceiling texture or single color shown in FIG. The program description of this operation is as shown in FIG. 14, and looks like FIG. 15 by clockwise culling. As a result, only the rear surface of the building wall surface viewed from the same viewpoint as FIG. 12 (the surface of the building wall surface) is displayed. At this time, the texture is set to a single color or lighting is turned off so that the seam on the back of the building wall is not visible. If the vertex description of the 3D model is made counterclockwise, the same display can be obtained by 3D drawing by counterclockwise culling.

  Since the 3D drawing means 35 performs hidden surface removal using a 3D graphics chip, the drawings in FIGS. 12 and 15 are erased from the hidden surface, and as a result, a 3D drawing of a building in which a ceiling is artificially drawn as shown in FIG. 16 is obtained. can get.

Returning to FIG. 3, the building 3D model storage means 36 stores a more realistic 3D model of the building such as an actual texture of the wall surface of the building and an actual three-dimensional shape. The storage building 3D model use determining means 37 is a building 3D model generating means when the building to be rendered corresponds to a specific point, a specific route, a specific area, or a specific polygon attribute. Instead of the building 3D model generated by 32, a more realistic building 3D model stored in the building 3D model storage means 36 is used for drawing.
As a result, as shown in FIG. 17, it is possible to display a realistic building 3D display that is closer to the actual landscape than a 3D map display that is generated by drawing a building 3D model from only the bottom polygon shape of the building. Become.

Embodiment 2. FIG.
In the above embodiment, the case where the building 3D model stored in the building 3D model storage means 36 is three-dimensional shape data not including the ceiling of the building has been described. However, as shown in FIG. The building ceiling may be divided into triangles in advance and stored as a building 3D model including the ceiling surface.
In this way, if the building ceiling is divided into triangles (or pseudo triangles) in advance, lighting can be applied to the building ceiling surface and textures can be applied, and only in a single color, single pattern or single texture. Compared with the pseudo ceiling drawing by the building wall back surface drawing means 34 that cannot be expressed, more various and realistic expressions are possible.

Next, the operation of the 3D drawing unit 35 will be described. The building 3D model (triangle primitive) stored in the building 3D model storage unit 36 is directly 3D-drawn by the 3D drawing unit 35 because the ceiling is pre-triangulated. That is, the 3D drawing means 35 draws the surface of the building wall surface and the ceiling, and erases the hidden surface by using the 3D graphics chip to draw the three-dimensional shape of the building.
Polygonal triangulation may be performed using a typical triangulation algorithm of computational geometry (for example, Atul Narkhede, Dinesh Manocha: "Fast Polygon Triangulation based on Seidel's Algorithm", Internet <URL http: //www.cs.unc .edu / ~ dm / CODE / GEM / chapter.html>).

Embodiment 3 FIG.
FIG. 19 is a functional configuration diagram of a building three-dimensional display unit according to Embodiment 3 of the present invention. Since the other configuration is the same as that of the first embodiment, differences from the first embodiment will be mainly described below.
The map data storage means 31 stores the bottom shape of the building (bottom surface polygon shape) and its attributes (including at least the height information of the building). The building 3D model generation means 32 is a method in which a polygon that is the bottom shape of the building is vertically set up by the height of the building from the polygonal shape and building attributes of the bottom polygon stored in the map data storage means 31. Then, a 3D model (three-dimensional shape) indicating the coordinates of the building in the three-dimensional space is generated. The steps so far are the same as those in the first embodiment.
Next, in the present embodiment, the building ceiling triangle dividing means 38 divides the polygon of the ceiling of the building into triangles online as shown in FIG. For the triangulation of a polygon, a triangulation algorithm in the field of computational geometry is used.
Next, the 3D drawing means 35 uses the 3D graphics chip to draw the surface and ceiling of the building wall constituting the building 3D model (divided into triangles by the building ceiling triangle dividing means 38) and hidden surface removal. And draw the 3D shape of the building. That is, a triangle primitive is drawn.

  In this way, by dividing the ceiling portion of the building into triangles, lighting can be applied to the ceiling of the building, and an arbitrary texture can be attached to the ceiling of the building, thereby enabling more realistic drawing.

Embodiment 4 FIG.
In the third embodiment, the building 3D model stored in the building 3D model storage means 36 has been described as a three-dimensional shape data in which the building ceiling is described as a polygon. However, FIG. 18 of the second embodiment. As shown in FIG. 5, the building ceiling composed of polygons may be divided into triangles in advance and stored as a building 3D model including the ceiling surface.
As described above, if the building ceiling is divided into triangles in advance, it is possible to save the time and effort of triangulating polygons online by the building ceiling triangle dividing means 38, and drawing can be performed with a small processing load.
FIG. 21 is a functional configuration diagram of the building 3D display unit at this time. The building model stored in the building 3D model storage unit 36 is directly converted into the 3D drawing unit without going through the building ceiling triangulation unit 38. 35 is drawn.

1 is a schematic configuration diagram illustrating a hardware configuration of a vehicle navigation system according to Embodiment 1. FIG. 1 is a configuration diagram showing a functional configuration of a vehicle navigation system according to Embodiment 1. FIG. FIG. 3 is a configuration diagram illustrating a functional configuration of a building three-dimensional display unit in FIG. 2 according to the first embodiment. FIG. 6 is an explanatory diagram for explaining a state of drawing on the building three-dimensional display unit according to the first embodiment. FIG. 10 is an explanatory diagram for explaining a culling function according to the first embodiment. It is a figure which concerns on Embodiment 1 and shows the bottom face polygon shape of the building stored in the map data storage means. FIG. 10 is a diagram for describing building 3D model generation from a bottom polygon shape of a building according to the first embodiment. FIG. 6 is an explanatory diagram illustrating an example of a description of a building 3D model according to the first embodiment. FIG. 4 is a diagram illustrating three-dimensional coordinates according to the first embodiment using a right-handed coordinate system (a) and a left-handed coordinate system (b). FIG. 10 is an explanatory diagram illustrating an example of a uv coordinate system of a texture on a building wall surface according to the first embodiment. FIG. 10 is an explanatory diagram illustrating an example of a program description of a 3D drawing operation on a building wall surface according to the first embodiment. FIG. 10 is an explanatory diagram illustrating an example of a 3D model drawing result on a building wall surface according to the first embodiment. FIG. 10 is an explanatory diagram illustrating an example of a uv coordinate system of a texture on a back surface of a building wall according to the first embodiment. FIG. 10 is an explanatory diagram illustrating an example of a program description of a 3D drawing operation on the back surface of a building wall according to the first embodiment. FIG. 10 is an explanatory diagram illustrating an example of a 3D model drawing result on the back surface of a building wall according to the first embodiment. FIG. 6 is an explanatory diagram illustrating an example of a 3D model drawing result of a building according to the first embodiment. It is explanatory drawing which concerns on Embodiment 1 and shows an example of the 3D model stored in the building 3D model storage means, and the building display result using it. FIG. 10 is an explanatory diagram illustrating an example of a 3D model stored in a building 3D model storage unit according to the second embodiment. FIG. 10 is a configuration diagram illustrating a functional configuration of a building three-dimensional display unit according to the third embodiment. FIG. 10 is a diagram for explaining triangulation of a building bottom polygon according to the third embodiment. FIG. 16 is a configuration diagram illustrating a functional configuration of a building three-dimensional display unit according to the fourth embodiment.

Explanation of symbols

11 GPS receiver, 12 ROM, 13 is RAM, 14 persistent storage, 15 microprocessor, 16 external storage, 17 external storage interface, 18 graphics chip, 19 frame buffer, 20 display monitor, 22 user interface, 23 vehicle position detection unit, 24 route search unit, 25 route guidance unit, 26 map display unit, 27 building 3D display unit, 28 common processing unit, 31 map data storage unit, 32 building 3D model generation unit, 35 3D drawing Means, 36 building 3D model storage means, 37 storage building 3D model use determining means, 38 building ceiling triangulation means.

Claims (4)

Map data storage means for storing attributes including at least one of the color, pattern and texture of the building ceiling and the height information of the building, and the bottom shape of the building;
A building 3D model generating unit that generates a building 3D model shape indicating coordinates in a three-dimensional space of the building using the bottom shape and height information of the building stored in the map data storage unit;
Using a 3D graphics chip, drawing of the surface of the building wall surface constituting the building 3D model generated by the building 3D model generation unit, and the building wall surface of the building 3D model generated by the building 3D model generation unit 3D drawing means for drawing the three-dimensional shape of the building by drawing with at least one of the color, pattern and texture of the building ceiling stored in the map data storage means on the back side and removing the hidden surface;
A three-dimensional landscape display device comprising display means for displaying a three-dimensional shape of a building drawn by the 3D drawing means. Map data storage means for storing attributes including building height information and the bottom shape of the building;
A building 3D model generating unit that generates a building 3D model shape indicating coordinates in a three-dimensional space of the building using the bottom shape and height information of the building stored in the map data storage unit;
Building ceiling triangulation means for dividing the bottom shape of the building into triangles as polygons of the building ceiling;
Using a three-dimensional graphics chip, the surface of the building wall constituting the building 3D model generated by the building 3D model generation means, the ceiling divided into triangles by the building ceiling triangulation means, and hidden surface removal are performed. 3D drawing means for drawing the three-dimensional shape of the building;
A three-dimensional landscape display device comprising display means for displaying a three-dimensional shape of a building drawn by the 3D drawing means. Building 3D model storage means for storing the 3D model of the building describing the 3D model shape and wall texture of the building;
When the building to be drawn corresponds to at least one of a specific point, a specific region, a specific route, and a specific polygon attribute in the map data, it is generated by the building 3D model generation means 3. A storage building 3D model use determination unit that determines to use a 3D model of a building stored in the building 3D model storage unit instead of the building 3D model storage unit. The three-dimensional landscape display device described. 4. The 3D landscape display device according to claim 3, wherein the building 3D model storage means divides a polygonal surface of a square or more constituting the building into triangles in advance and stores them as triangles.

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