WO2009128585A1

WO2009128585A1 - Three dimensional modeling method for linear road data and apparatus for executing the method

Info

Publication number: WO2009128585A1
Application number: PCT/KR2008/003789
Authority: WO
Inventors: Jung Kak Seo
Original assignee: Thinkware Systems Corporation
Priority date: 2008-04-15
Filing date: 2008-06-29
Publication date: 2009-10-22
Also published as: KR100879452B1

Abstract

A three-dimensional (3D) modeling apparatus and method of linear road data is provided. The 3D modeling apparatus of linear road data, the 3D modeling apparatus including: a vector information calculation unit calculating vector information of the linear road data; a shape forming unit generating shape data with respect to the linear road data using the vector information; and a polygon construction unit constructing a polygon of the shape data of the linear road data.

Description

THREE DIMENSIONAL MODELING METHOD FOR LINEAR ROAD DATA AND APPARATUS FOR EXECUTING THE METHOD

Technical Field The present invention relates to a map data generation method for a three- dimensional (3D) map service, and more particularly, a 3D modeling method and apparatus of linear road data which constructs a polygon of linear road data about a tunnel or an underground passage, and thereby may three-dimensionally display the linear road data.

Background Art

A Geographic Information System (GIS) may indicate an information system that integrates and processes attribute data associated with geographic data.

Location information such as a longitude, a latitude, and an address may be easily retrieved using a GIS. A GIS may convert geographic information, desired by a user, into an image in a map form through a query and analysis about spatial data of a relational database.

Currently, a GIS-based map service is provided through a terminal such as a navigation system in a mobile environment. The navigation system receives predetermined data from a Global Positioning

System (GPS) satellite orbiting above the Earth using a GPS receiver, and calculates its own location based on the received data. The navigation system may provide a map image of a location desired by a user as well as a map image where a location of a moving object is map-matched to previously stored map data. General road data used for a map service of the GIS or navigation system may be configured as linear data having a plurality of interpolation points.

In general, the linear data is required to be processed based on a road width in order to use the linear data as display data for a map image.

In particular, data configuring a three-dimensional (3D) polygon may be used as display data to three-dimensionally display linear data about a tunnel or an underground passage.

However, when all tunnels and underground passages in a map are modeled as polygon data and displayed, time and cost required to generate map data may increase, and an amount of data for a map service may significantly increase.

Disclosure of Invention Technical Goals

An aspect of the present invention provides a three-dimensional (3D) modeling apparatus and method of linear road data which may construct a polygon corresponding to a shape of a tunnel or an underground passage using linear road data, and thereby may three-dimensionally display the tunnel or the underground passage.

Technical solutions

According to an aspect of the present invention, there is provided a three- dimensional (3D) modeling apparatus of linear road data, the 3D modeling apparatus including: a vector information calculation unit calculating vector information of the linear road data; a shape forming unit generating shape data with respect to the linear road data using the vector information; and a polygon construction unit constructing a polygon of the shape data with respect to the linear road data.

According to an aspect of the present invention, the linear road data may correspond to at least one of a tunnel and an underground passage. According to an aspect of the present invention, the vector information calculation unit may calculate a direction vector of a straight line connecting two adjacent interpolation points with respect to interpolation points of the linear road data, and calculate a linear normal vector of each of the interpolation points using the direction vector. According to an aspect of the present invention, the shape forming unit may generate shape data indicating a form of the tunnel with respect to each of the interpolation points, and calculates mapping coordinates for mapping a predetermined tunnel texture with respect to the shape data.

According to an aspect of the present invention, the shape forming unit may generate the shape data to enable the form of the tunnel to be in an approximate shape of a hemisphere based on the linear normal vector with respect to a location and a direction of each of the interpolation points. According to an aspect of the present invention, the tunnel texture may include a hemisphere image indicating the form of the tunnel and a road image indicating a road surface in the tunnel.

According to an aspect of the present invention, the shape forming unit may generate shape data, indicating an entrance of the tunnel, with respect to an interpolation point corresponding to a starting point of the tunnel, and generate shape data, indicating an exit of the tunnel, with respect to an interpolation point corresponding to an end point of the tunnel.

According to an aspect of the present invention, the shape forming unit may divide the shape data indicating the entrance of the tunnel or the exit of the tunnel into two pieces of symmetrical data, and generate radial data centered on a predetermined point.

According to an aspect of the present invention, the shape forming unit may generate the shape data indicating the entrance of the tunnel, the entrance having a size in proportion to the shape data.

According to an aspect of the present invention, the polygon construction unit may construct a polygon of the shape data between the two adjacent interpolation points.

According to an aspect of the present invention, there is provided a 3D modeling method of linear road data, the 3D modeling method including: calculating vector information of the linear road data; generating shape data with respect to the linear road data using the vector information; and constructing a polygon of the shape data with respect to the linear road data.

Advantageous effects According to an embodiment of the present invention, a three-dimensional (3D) modeling method and apparatus of linear road data may provide a 3D modeling algorithm that may construct a polygon with respect to linear road data for a 3D map service, and thereby may provide an improved map image.

Also, according to an embodiment of the present invention, a 3D modeling method and apparatus of linear road data may three-dimensionally display a shape of a tunnel using linear data, and thereby may reduce an amount of data for a 3D map service and reduce a time and cost for the 3D map service. Brief Description of Drawinfis

FIG. 1 is a flowchart illustrating a three-dimensional (3D) modeling method of linear road data according to an embodiment of the present invention; FIG. 2 is a diagram illustrating an example for describing an operation of calculating a direction vector and a linear normal vector of linear road data according to an embodiment of the present invention;

FIG. 3 is a flowchart illustrating an operation of 3D modeling of linear road data; FIG. 4 is a diagram illustrating an example for describing an operation of generating a 3D tunnel;

FIG. 5 is a diagram illustrating an example of a texture representing a 3D tunnel;

FIG. 6 is a diagram illustrating an example for describing an operation of generating an entrance and an exit of a 3D tunnel;

FIG. 7 is a diagram illustrating operations of generating a 3D tunnel;

FIG. 8 is a diagram illustrating an example for describing an operation of constructing a polygon index of a 3D tunnel;

FIG. 9 is a diagram illustrating an example of 3D tunnel data generated according to a 3D modeling method of linear road data according to an embodiment of the present invention; and

FIG. 10 is a block diagram illustrating a configuration of a 3D modeling apparatus of linear road data according to an embodiment of the present invention.

Best Mode for Carrying Out the Invention

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present invention by referring to the figures. The present invention relates to a display method for a three-dimensional (3D) map service. The display method may enable linear road data to be used as 3D display data. In the present specification, 'linear road data' may indicate road information about a tunnel and an underground passage from among geographical information on a map.

FIG. 1 is a flowchart illustrating a 3D modeling method of linear road data according to an embodiment of the present invention.

In operation SlOl, a 3D modeling apparatus according to an embodiment of the present invention may calculate vector information of the linear road data. The calculation may be a process for constructing a polygon of the linear road data. The

3D modeling apparatus may calculate a direction vector and a linear normal vector of the linear road data using linear information included in the linear road data.

The calculating in operation SlOl is described in greater detail with reference to FIG 2.

In operation S 102, the 3D modeling apparatus may generate shape data with respect to the linear road data using the vector information calculated in operation SlOl. The 3D modeling apparatus may generate shape data representing a particular shape of the road information to enable linear road data corresponding to the particular shape to be represented three-dimensionally and accurately.

The above generating in operation S 102 is described in greater detail with reference to FIGS. 3 through 7. In operation S103, the 3D modeling apparatus may construct a polygon of the shape data generated in operation S 102. The 3D modeling apparatus may construct the polygon of the generated shape data to enable the linear road data to be used as 3D display data.

The constructing in operation S 103 is described in greater detail with reference to FIG. 8.

The 3D modeling apparatus may generate shape data of corresponding road information using linear information of linear road data, construct a polygon of the generated shape data, and thereby may three-dimensionally display the linear road data.

The 3D modeling apparatus may perform 3D modeling with respect to linear road data corresponding to at least one of a tunnel and an underground passage. Hereinafter, the calculating in operation SlOl, the generating in operation S 102, and the constructing in operation S 103 are described using a tunnel as an example. The calculating of the vector information of the linear road data in operation SlOl is described below.

FIG. 2 is a diagram illustrating an example for describing the operation of calculating the direction vector and the linear normal vector of the linear road data according to an embodiment of the present invention.

The direction vector and the linear normal vector of the linear road data is required to be calculated to generate 3D display data of the tunnel (hereinafter, referred to as '3D tunnel data').

As illustrated in FIG. 2, the linear road data may be configured to have n interpolation points (P), that is, may be represented as a straight line connecting interpolation points P₀ to P_n-i.

The 3D modeling apparatus may calculate a direction vector ^ of each straight line connecting two adjacent interpolation points with respect to the interpolation points (P) of the linear road data. The direction vector ^ may be calculated by,

[Equation 1]

where i may be 1 to n-1. ___t

Also, the 3D modeling apparatus may calculate a linear normal vector with respect to each of the interpolation points (P) using the calculated direction vector.

The linear normal vector "ZZ may be calculated by, [Equation 2]

where i may be 0 to n-1, and R may denote a 90° rotation conversion matrix. As shown in Equation 2, a linear normal vector of a starting point P₀ and an end point P_n-1 of the interpolation points (P) may be orthogonal to a direction vector of a corresponding interpolation point. Also, a linear normal vector of other interpolation points excluding the starting point Po and the end point P_n-) may be calculated using a difference between two direction vectors.

Accordingly, when vector calculation of the linear road data is completed, the shape data of the linear road data may be generated using the calculated vector information.

The generating of the shape data of the linear road data in operation S 102 is described below.

FIG. 3 is a flowchart illustrating the operation of 3D modeling of linear road data. In operation S301, the 3D modeling apparatus may generate shape data indicating a form of the tunnel with respect to each of the interpolation points (P) of the linear road data. The shape data indicating the form of the tunnel may be in an approximate shape of a hemisphere.

In general, a tunnel may be in a shape of a hemisphere based on a real shape of a tunnel. As illustrated in FIG. 4, the 3D modeling apparatus may calculate shape data of the hemisphere with respect to each of the interpolation points (P) based on the linear normal vector to display the tunnel more three-dimensionally. In this instance, the shape data of the hemisphere is required to be generated based on a location and a direction of each of the interpolation points (P) to be appropriate for a road shape. Also, the shape data of the hemisphere may include a plurality of connection points ^lθ for the hemisphere shape.

The shape data of the hemisphere may be calculated based on a linear normal vector with respect to a predetermined interpolation point using, [Equation 3]

where θ may be 0° to 180°, t may denote a radius of the hemisphere, ^θ may denote a conversion matrix rotating by θ on £>, and jy _t may denote the linear normal vector.

When a value of θ is small in Equation 3, the shape data may be similar to the hemisphere or an amount of data may increase. Conversely, when the value of θ is great, the shape data may be in a polygon shape as opposed to the hemisphere although the amount of data may decrease. Accordingly, the tunnel may be displayed less realistically.

In operation S302, the 3D modeling apparatus may calculate texture mapping coordinates for mapping a predetermined tunnel texture with respect to the shape data generated in operation S301.

The tunnel texture may include a hemisphere image (a) of FIG. 5 and a road image (b) of FIG. 5. The hemisphere image (a) of FIG. 5 may indicate the form of the tunnel, and the road image (b) of FIG. 5 may indicate a road surface in the tunnel. The texture mapping coordinates (U, V) may be calculated by,

[Equation 4]

U = λ(θ/ π)

where λ may denote a ratio of the hemisphere image in the tunnel texture, d( P_{1 0} R₊A p p

¹ ' ^x may denote a distance between ' and "' , and t may denote a radius of the hemisphere.

The 3D modeling apparatus may calculate the texture mapping coordinates (U, V) with respect to each of the interpolation points (P) of the linear road data, and map the tunnel texture according to the calculated texture mapping coordinates (U, V).

In operation S3O3, the 3D modeling apparatus may generate shape data indicating an entrance of the tunnel with respect to an interpolation point corresponding to a starting point of the tunnel, and generate shape data indicating an exit of the tunnel with respect to an interpolation point corresponding to an end point of the tunnel to display the 3D tunnel data more graphically.

As illustrated in FIG. 6, the 3D modeling apparatus may divide the shape data indicating the entrance of the tunnel or the exit of the tunnel into two pieces of symmetrical data, and generate radial data. In this instance, a plurality of connection points may be arranged in the radial data on predetermined points O and O'. Particularly, the 3D modeling apparatus may generate the shape data indicating the entrance having a size in proportion to the shape data generated in operation S301. FIG. 7 is a diagram illustrating operations of generating a 3D tunnel.

The 3D modeling apparatus may generate shape data 701 in a hemisphere shape with respect to each interpolation point (P) of linear road data as illustrated in (b) of FIG. 7 to generate 3D tunnel data using the linear road data illustrated in (a) of FIG. 7. Here, the shape data 701 of the hemisphere may indicate a form of the tunnel, and the linear road data in (a) of FIG. 7 may include linear information only. Also, the 3D modeling apparatus may calculate texture mapping coordinates with respect to the shape data 701 of the hemisphere, and map a tunnel texture 702 according to a corresponding texture mapping coordinates as illustrated in (c) of FIG. 7. Also, the 3D modeling apparatus may additionally generate shape data indicating the form of the tunnel as well as shape data 703 indicating an entrance/exit of the tunnel as illustrated in (d) of FIG. 7 to display the 3D tunnel data more graphically.

The constructing of the polygon of the shape data in operation S 103 is described below. FIG. 8 is a diagram illustrating an example for describing an operation of constructing a polygon index of a 3D tunnel.

When the 3D modeling apparatus constructs the polygon of the shape data of the hemisphere, 3D tunnel data that may be three-dimensionally displayed may be generated. In this instance, the shape data of the hemisphere may include a plurality of p connection points ^ιθ with respect to each of the interpolation points (P) of the linear road data.

Shape data indicating the form of the tunnel and shape data indicating an entrance/exit of the tunnel may be divided and the constructing of the polygon may be performed, respectively. As illustrated in FIG. 8, the 3D modeling apparatus may construct a polygon of the shape data of the hemisphere between two adjacent interpolation points. The 3D modeling apparatus may construct a polygon index (T₁) with respect to the shape data of the hemisphere by,

[Equation 5] τ_t (j, q + J, q + ι + JX Qf i = odd)

T_t O\ q + l + 7,1 + JX (if i = even) where T(i, j, k) may denote a polygon constructed by an i' point, a j^th point, and a k^th point, i may be 0 to n-p, j and q may be 0 to nc, ny may denote a number of polygons, and nc may denote a number of connection points of the shape data.

The 3D modeling apparatus may calculate the vector information of the linear road data, generate the shape data indicating the actual form of the tunnel, and construct the polygon index with respect to the shape data to three-dimensionally display the tunnel using the linear information.

FIG. 9 is a diagram illustrating an example of 3D tunnel data generated according to a 3D modeling method of linear road data according to an embodiment of the present invention. As illustrated in FIG. 9, a 3D modeling apparatus may construct a polygon with respect to a shape 901 and a shape 902 using linear information of the linear road data, and thereby may three-dimensionally display the shape 901 and the shape 902. Here, the shape 901 may indicate a form of a tunnel and the shape 902 may indicate an entrance/exit of the tunnel. Hereinafter, a configuration of the 3D modeling apparatus, which performs the

3D modeling method of the linear road data, is described. FIG. 10 is a block diagram illustrating a configuration of the 3D modeling apparatus of linear road data according to an embodiment of the present invention.

As illustrated in FIG. 10, the 3D modeling apparatus of the linear road data may include a map database 110, a retrieval unit 120, a storage unit 130, and a 3D modeling module 140.

The map database 110 may store and maintain map data about a national map. In particular, the map database 110 may store and maintain linear road data associated with road information about at least one of a tunnel and an underground passage from among the map data. The map database 110 may store and maintain linear information associated with the linear road data. Here, the linear information may include location information of each interpolation point of the linear road data.

The retrieval unit 120 may retrieve predetermined linear road data and linear information associated with the linear road data from the map database 110. The storage unit 130 may temporarily store the linear information and the linear road data retrieved by the retrieval unit 120.

The 3D modeling module 140 may be operated for 3D modeling of the linear road data. Specifically, the 3D modeling module 140 may generate a shape data for corresponding road information using the linear information of the linear road data, and construct a polygon with respect to the generated shape.

The 3D modeling module 140 may include a vector information calculation unit 141, a shape forming unit 142, and a polygon construction unit 143.

The vector information calculation unit 141 may calculate a direction vector of each straight line connecting two adjacent interpolation points with respect to interpolation points of the linear road data. Also, the vector information calculation unit 141 may calculate a linear normal vector of each of the interpolation points using the direction vector.

In this instance, the direction vector ® of each of the straight lines may be calculated by,

LJi — r_t r_iA

where i may be 1 to n-1 and P may denote an interpolation point. Also, the linear normal vector ^ of each of the interpolation points may be calculated by,

N₁ = RD_h Qf i = 0, n - l)

Ni = Di - Di₊i , (I/ I ≠ 0, It - I)

where i may be 0 to n-1, and R may denote a 90° rotation conversion matrix. The shape forming unit 142 may generate shape data indicating a form of the tunnel with respect to each of the interpolation points when the linear road data corresponds to a tunnel. In this instance, the shape data may be in a shape of a hemisphere.

The shape forming unit 142 may calculate the shape data of the hemisphere based on the linear normal vector ^ with respect to a predetermined interpolation point.

In this instance, the shape data of the hemisphere may include a plurality of connection points C ^lθ . The connection points C ^lθ may be given by,

where θ may be 0° to 180°, t may denote a radius of the hemisphere, nft ~ θ may denote a conversion matrix rotating by θ on

The shape forming unit 142 may adjust a value of θ to enable the shape data of the tunnel to be in an approximate shape of the hemisphere.

The shape forming unit 142 may calculate texture mapping coordinates (U, V) for mapping a predetermined tunnel texture with respect to the shape data of the hemisphere.

The texture mapping coordinates (U, V) may be calculated by,

U = λ{θ/ π) V = d(P, , P_M)/t

where λ may denote a ratio of the hemisphere image in a tunnel texture, d(P ' ' P ^⁺I )-⁷ may denote a distance between ' and "^l , and t may denote a radius of the hemisphere.

The 3D modeling module 140 may calculate the texture mapping coordinates (U, V) with respect to each of the interpolation points of the linear road data and map the tunnel texture according to the calculated texture mapping coordinates (U, V) through the shape forming unit 142. The shape forming unit 142 may generate shape data indicating an entrance of the tunnel with respect to an interpolation point corresponding to a starting point of the tunnel, and generate shape data indicating an exit of the tunnel with respect to an interpolation point corresponding to an end point of the tunnel. Also, the shape forming unit 142 may divide the shape data indicating the entrance of the tunnel or the exit of the tunnel into two pieces of symmetrical data, and generate radial data on a predetermined point. In this instance, the entrance may have a size in proportion to the shape data of the hemisphere. The polygon construction unit 143 may construct a polygon of the shape data of the hemisphere constructed by the plurality of connection points C ^l0 with respect to each of the interpolation points of the linear road data.

The polygon construction unit 143 may separate the shape data indicating the form of the tunnel from the shape data indicating the entrance/exit of the tunnel, and construct the polygon for the shape data, respectively.

The polygon construction unit 143 may construct a polygon index (T₁) of the shape data of the hemisphere between two adjacent interpolation points using,

T₁ (J₉ Q + J, <1 + 1 + JX ⁽if * = odd)

TXJ,q + l + 7,1 + JX (if i = even) where T(i, j, k) may denote a polygon constructed by an i^th point, a j^th point, and a k^th point, i may be 0 to nγ, j and q may be 0 to nc, nx may denote a number of polygons, and nc may denote a number of connection points of the shape data. Accordingly, the 3D modeling apparatus may automatically generate 3D tunnel data using the 2D linear road data including the linear information, use the 3D tunnel data as 3D display data, and thereby may reduce an amount of data for a 3D map service.

The exemplary embodiments of the present invention include computer-readable media including program instructions to implement various operations embodied by a computer. The media may also include, alone or in combination with the program instructions, data files, data structures, tables, and the like. The media and program instructions may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well known and available to those having skill in the computer software arts. Examples of computer-readable media include magnetic media such as hard disks, floppy disks, and magnetic tape; optical media such as CD ROM disks; magneto-optical media such as floptical disks; and hardware devices that are specially configured to store and perform program instructions, such as readonly memory devices (ROM) and random access memory (RAM). Examples of program instructions include both machine code, such as produced by a compiler, and files containing higher level code that may be executed by the computer using an interpreter. The described hardware devices may be configured to act as one or more software modules in order to perform the operations of the above-described embodiments of the present invention, or vice versa.

Although a few embodiments of the present invention have been shown and described, the present invention is not limited to the described embodiments. Instead, it would be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A three-dimensional (3D) modeling apparatus of linear road data, the 3D modeling apparatus comprising: a vector information calculation unit calculating vector information of the linear road data; a shape forming unit generating shape data with respect to the linear road data using the vector information; and a polygon construction unit constructing a polygon of the shape data with respect to the linear road data.

2. The 3D modeling apparatus of claim 1, wherein the linear road data corresponds to at least one of a tunnel and an underground passage.

3. The 3D modeling apparatus of claim 1, wherein the vector information calculation unit calculates a direction vector of a straight line connecting two adjacent interpolation points with respect to interpolation points of the linear road data, and calculates a linear normal vector of each of the interpolation points using the direction vector.

4. The 3D modeling apparatus of claim 3, wherein the vector information calculation unit calculates the direction vector ^ using, [Equation 1]

where P denotes an interpolation point, and i is 1 to n-1, and the linear normal vector ™ is calculated using, [Equation 2]

Ni = Di -Bi₊I, (if i ≠ 0₉ n - l) where i is 0 to n-1, and R denotes a 90° rotation conversion matrix.

5. The 3D modeling apparatus of claim 3, wherein the linear road data corresponds to a tunnel, and the shape forming unit generates shape data indicating a form of the tunnel with respect to each of the interpolation points, and calculates mapping coordinates for mapping a predetermined tunnel texture with respect to the shape data.

6. The 3D modeling apparatus of claim 5, wherein the shape forming unit generates the shape data to enable the form of the tunnel to be in an approximate shape of a hemisphere based on the linear normal vector with respect to a location and a direction of each of the interpolation points.

7. The 3D modeling apparatus of claim 6, wherein the shape forming unit ggeenneerraatteess tthhee shape data ^ιβ of the hemisphere by, [Equation 3]

C_iθ = tR°^> N_t

where θ is 0° to 180°, t denotes a radius of the hemisphere, ϋ denotes a conversion matrix rotating by θ on ' and, denotes the linear normal jy- vector.

8. The 3D modeling apparatus of claim 5, wherein the tunnel texture includes a hemisphere image indicating the form of the tunnel and a road image indicating a road surface in the tunnel.

9. The 3D modeling apparatus of claim 8, wherein the shape forming unit calculates the mapping coordinates (U, V) using, [Equation 4] U = λiθl π) V = d(P_t ,P_M) /t where λ denotes a ratio of the hemisphere image in the tunnel texture, d(R , P₁₊₁ ) denotes a distance between _p ' and _P ^{l Λ} , and t denotes a radius of the hemisphere.

10. The 3D modeling apparatus of claim 5, wherein the shape forming unit generates shape data, indicating an entrance of the tunnel, with respect to an interpolation point corresponding to a starting point of the tunnel, and generates shape data, indicating an exit of the tunnel, with respect to an interpolation point corresponding to an end point of the tunnel.

11. The 3D modeling apparatus of claim 10, wherein the shape forming unit divides the shape data indicating the entrance of the tunnel or the exit of the tunnel into two pieces of symmetrical data, and generates radial data centered on a predetermined point.

12. The 3D modeling apparatus of claim 10, wherein the shape forming unit generates the shape data indicating the entrance of the tunnel, the entrance having a size in proportion to the shape data.

13. The 3D modeling apparatus of claim 5, wherein the polygon construction unit constructs a polygon of the shape data between the two adjacent interpolation points.

14. The 3D modeling apparatus of claim 13, wherein the polygon construction unit constructs a polygon index T₁ with respect to the shape data by,

[Equation 5] T_i {j, q + j, q + l + j\ (if i = odd)

^Ti (J₉ q + l + j₉l + J)₉ (if i = even) where T(i, j, k) denotes a polygon constructed by an i^th point, a j^th point, and a k^l point, i is 0 to n-p, j and q are 0 to nc, nj denotes a number of polygons, and nc denotes a number of connection points of the shape data.

15. A 3D modeling method of linear road data, the 3D modeling method comprising: calculating vector information of the linear road data; generating shape data with respect to the linear road data using the vector information; and constructing a polygon of the shape data with respect to the linear road data.

16. The 3D modeling method of claim 15, wherein the linear road data corresponds to at least one of a tunnel and an underground passage.

17. The 3D modeling method of claim 15, wherein the calculating comprises: calculating a direction vector of a straight line connecting two adjacent interpolation points with respect to interpolation points of the linear road data; and calculating a linear normal vector of each of the interpolation points using the direction vector.

18. The 3D modeling method of claim 17, wherein the direction vector 3 is calculated using, [Equation 6]

where P denotes an interpolation point, and i is 1 to n-1, and the linear normal vector — is calculated using, [Equation 7]

Nt = Oi - DM , (i/ i ≠ O, w - l) where i is 0 to n-1, and R denotes a 90° rotation conversion matrix.

19. The 3D modeling method of claim 17, wherein the linear normal data corresponds to a tunnel, and the forming of the shape data comprises: generating shape data indicating a form of the tunnel with respect to each of the interpolation points; and calculating mapping coordinates for mapping a predetermined tunnel texture with respect to the shape data.

20. The 3D modeling method of claim 19, wherein the shape data is generated to enable the form of the tunnel to be in an approximate shape of a hemisphere based on the linear normal vector with respect to a location and a direction of each of the interpolation points.

C

21. The 3D modeling method of claim 20, wherein the shape data ^iθ of the hemisphere is given by, [Equation 8]

C_iθ = tR? N₁ where θ is 0° to 180°, t denotes a radius of the hemisphere, R ^θDl denotes a a conversion matrix rotating by θ on ' and, jy denotes the linear normal vector.

22. The 3D modeling method of claim 19, wherein the tunnel texture includes a hemisphere image indicating the form of the tunnel and a road image indicating a road surface in the tunnel.

23. The 3D modeling method of claim 22, wherein the mapping coordinates (U, V) is calculated using,

[Equation 9] U = λ{θ/ π)

where λ denotes a ratio of the hemisphere image in the tunnel texture, d(P ₉ P ₁ ) p p denotes a distance between ' and ^lΛ , and t denotes a radius of the hemisphere.

24. The 3D modeling method of claim 19, wherein the generating of the shape data further comprises: generating shape data indicating an entrance of the tunnel with respect to an interpolation point corresponding to a starting point of the tunnel; and generating shape data indicating an exit of the tunnel with respect to an interpolation point corresponding to an end point of the tunnel.

25. The 3D modeling method of claim 24, wherein the generating of the shape data indicating the entrance of the tunnel and the generating of the shape data indicating the exit of the tunnel divides the shape data indicating the entrance of the tunnel or the exit of the tunnel into two pieces of symmetrical data, and generates radial data centered on a predetermined point.

26. The 3D modeling method of claim 24, wherein the generating of the shape data indicating the entrance of the tunnel generates the shape data indicating the entrance of the tunnel, the entrance having a size in proportion to the shape data.

27. The 3D modeling method of claim 19, wherein the constructing of the polygon constructs a polygon of the shape data between the two adjacent interpolation points.

28. The 3D modeling method of claim 27, wherein the constructing of the polygon constructs a polygon index T, with respect to the shape data by,

[Equation 10] TXJ_^ q + j, q + l + JX (if i = odd) T_t (J₇ q + 1 + j,l + j% (if i = even) where T(i, j, k) denotes a polygon including an i^th point, a j^th point, and a k^th point, i is 0 to nγ, j and q are 0 to nc, n-γ denotes a number of polygons, and nc denotes a number of connection points of the shape data.

29. A computer-readable recording medium storing a program for implementing the method according to any one of claims 15 through 28.