KR101552828B1 - Method for Obtaining Polygon Information of Three-dimensional Object Model - Google Patents

Abstract

The present invention relates to a polygon information extraction method of a three-dimensional object model, and more particularly, to a polygon information extraction method of a three-dimensional object model performed by a rendering processing apparatus for expressing a shape of a three-dimensional object model or a two- Constructing a plurality of three-dimensional polygons by arranging three-dimensional vertex coordinates forming the shape of the three-dimensional object model on the basis of a vertex index; Intersecting the three-dimensional object model with a target plane including a horizontal or vertical cross-section of the three-dimensional object model; Dimensional polygons are generated by extracting intersection information by checking whether an intersection where one surface of a plurality of three-dimensional polygons intersects with the target plane is generated is detected based on the target plane, and when a plurality of intersections occur in the three- Extracting and storing at least one connected intersection segment; And analyzing a connection relation of the at least one intersection line segment and constructing the closed two-dimensional polygon information by merging the intersection line segments according to the analyzed connection relation. Accordingly, the present invention extracts the cross-sectional information of the three-dimensional object model as two-dimensional polygon information, and generates a two-dimensional object model using the two-dimensional polygon information. Based on the two-dimensional polygon information, And can be used as basic data for authoring two-dimensional contents such as a document.

Description

A method for extracting polygon information of a three-dimensional object model {

The present invention relates to a polygon information extraction method for a three-dimensional object model, and more particularly, to a two-dimensional polygon information extraction method for extracting two-dimensional polygon information about a desired point from three- And a method of extracting polygon information of a 3D object model.

Most car and portable navigation devices rely on a two-dimensional navigation map to visualize key features, such as buildings, in 2D, but a three-dimensional vehicle navigation system is emerging. Most of these 3D navigation systems use photorealistic rendering techniques to visualize 3D building data.

This visualization technique based on realistic rendering requires accurate geometric models and detailed realistic building textures, and it is necessary to match the rendered 3D buildings, roads or other objects with actual buildings, roads or other objects as closely as possible have.

A three-dimensional mesh (Mesh) refers to a bundle of data, such as a point, a plane, used to represent an object in three dimensions on a graphical basis. These three-dimensional meshes are widely applied to various applications representing three-dimensional objects. The three-dimensional mesh consists of triangles made up of vertices and three vertices, and these triangles are gathered to complete one complete mesh. In real life, in order to express a building in three dimensions, the information of a triangle is connected to one another in a complicated shape.

As prior art data, Korean Patent Laid-Open No. 2009-0076412 proposes a method and apparatus for generating a vertex having a three-dimensional position corresponding to a depth value of each of pixels of a depth image representing an object, For each pixel belonging to the non-boundary of the object among the pixels, the polygon mesh is grouped by grouping the belonging pixel and the adjacent pixels of the belonging pixel and connecting the vertices to each other considering the grouped results.

Korean Patent Laid-Open Publication No. 10-2014-0040416 discloses a three-dimensional object generation apparatus and a method thereof. The three-dimensional object generation apparatus divides the components of a two-dimensional web page into a plurality of polygons, When an object manipulation signal is input in the generated 3D object, a 3D transform matrix is generated by changing the vertex coordinate value of the corresponding individual grid element according to the object manipulation signal, and a 3D transform matrix is applied to the predefined CSS transform, And a three-dimensional object manipulation processor for generating a dimensional object.

As described above, a technique for generating a three-dimensional object based on a three-dimensional mesh requires a basic three-dimensional transformation technique and a two-dimensional transformation technique (2D transformation) Dimensional polygon information such as a cross-sectional view can not be extracted.

Therefore, in order to extract the shape information of a two-dimensional building that is easy for a person to recognize based on a plane of height designated by a user in a conventional three-dimensional building having a precise and complicated shape, There is a problem that the shape information of the two-dimensional building must be directly drawn by the user.

In the case of a three-dimensional building, since the three-dimensional model is merely representing the overall shape, not only the floor layout and the floor plan can be confirmed, but also it can not be applied to the building analysis and statistical system performed in two dimensions. That is, there is a problem that it is not possible to directly express the dimension and the layout in a two-dimensional drawing format even though the three-dimensional model can individually confirm dimensions and arrangements. Therefore, in order for the user to check the dimensions and the layout of the building and to check the detailed configurations, a two-dimensional drawing in which concrete data is written in an obvious manner, for example, a floor plan or a sectional view corresponds to an essential element can do.

Korean Patent Application No. 2007-0049774 discloses a method of creating a two-dimensional drawing by extracting multidimensional shape information and attribute information of a corresponding object from multidimensional object information, .

Even a program for such a three-dimensional model has a problem that it can not directly use the function of converting a three-dimensional model into a two-dimensional drawing even if it is converted into a two-dimensional drawing. That is, the data created from the two-dimensional drawing from the three-dimensional model data by using the basic function is inferior to the drawing created by artificially using the AUTOCAD, the drawing itself is coarse, and the expressed information The amount and quality level of the user is very low, so that the user must carry out the work again with the direct measurement.

In addition, since the two-dimensional drawings converted from the three-dimensional model data must manually fill in the dimensions or the arrangement of the components, the user must fill in the wrong information, which is different from the original design, have.

Korean Patent Publication No. 2009-0076412 "Modeling Method and Apparatus" Korean Patent Laid-Open No. 10-2014-0040416 "3D object generation apparatus and method thereof" Korean Patent Publication No. 2007-0049774 "How to Create a Multidimensional Model as a Two-Dimensional Drawing"

The present invention extracts points physically intersecting a target plane and a three-dimensional object model with reference to a target plane of a height specified in a three-dimensional object model, and analyzes connection relationships for connecting the points to a closed two- Dimensional shape information of a three-dimensional object model that can be easily recognized by a user in a three-dimensional object model having a precise and complex shape by providing two-dimensional shape information.

Among the embodiments, a polygon information extraction method of a three-dimensional object model is a polygon information extraction method of a three-dimensional object model performed by a rendering processing apparatus for expressing a shape of a three-dimensional object model or a two- Constructing a plurality of three-dimensional polygons by arranging three-dimensional vertex coordinates forming a shape of the three-dimensional object model on the basis of a vertex index; Intersecting the three-dimensional object model with a target plane including a horizontal or vertical cross-section of the three-dimensional object model; Dimensional polygons are generated by extracting intersection information by checking whether an intersection where one surface of a plurality of three-dimensional polygons intersects with the target plane is generated is detected based on the target plane, and when a plurality of intersections occur in the three- Extracting and storing at least one connected intersection segment; And analyzing a connection relation to the at least one intersection line segment, and constructing the closed two-dimensional polygon information by merging the intersection line segments according to the analyzed connection relationship.

The target plane is composed of a plurality of polygons, and is formed to be larger than a cross section of the three-dimensional object model.

Dimensional polygons are generated by extracting intersection information by checking whether an intersection where one surface of a plurality of three-dimensional polygons intersects with the target plane is generated is detected based on the target plane, and when a plurality of intersections occur in the three- The step of extracting and storing at least one intersection line segment connected may include extracting coordinates of the intersection point by line segments of the three-dimensional polygon and storing the intersection point information as intersection information; And setting two intersection points as a start point and an end point when two intersection points exist for each line segment of the three dimensional polygon and extracting and storing an intersection line segment connecting the start point and the end point for each segment of the three dimensional polygon .
The step of analyzing the connection relation with respect to the at least one intersection line segment and constructing the closed two-dimensional polygon information by merging the intersection line segments according to the analyzed connection relationship may include: Identifying an intersection line segment having the same coordinate value as the starting point of the line segment and confirming the connection relation; And constructing coordinates of a closed two-dimensional polygonal space by connecting all intersection lines extracted and stored for each line segment of the three-dimensional polygon in such a manner that the end points having the same coordinate value and the starting point are mutually merged .

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The closed-form two-dimensional polygon information is a two-dimensional shape information of a vertical section or a horizontal section of the three-dimensional object model.

The polygon information extraction method of the three-dimensional object model of the present invention extracts the cross-sectional information of the three-dimensional object model as two-dimensional polygon information, generates a two-dimensional object model using the two-dimensional polygon information, Based on the information, it can be used as basic data for authoring two-dimensional contents such as floor plans and maps, and can be applied to building analysis and statistics system using existing two-dimensional data, It is effective.

1 is a view for explaining a rendering processing apparatus for performing a polygon information extraction method of a three-dimensional object model according to an embodiment of the present invention.
2 is a flowchart illustrating a method of extracting polygon information of a three-dimensional object model according to an exemplary embodiment of the present invention.
3 is a view for explaining the shape of the three-dimensional object model of FIG.
FIG. 4 is a view for explaining polygon information for the 3D object model of FIG. 3. FIG.
FIG. 5 is a view for explaining a state in which a target plane is arranged in the three-dimensional object model of FIG. 3. FIG.
Fig. 6 is a view for explaining points where the polygon of Fig. 5 intersects with the target plane.
FIG. 7 is a view for explaining an analysis process for a point at which a first line segment of the polygon shown in FIG. 5 intersects with a target plane.
FIG. 8 is a view for explaining an analysis process for a point at which a second line segment of the polygon shown in FIG. 5 intersects with a target plane.
FIG. 9 is a view for explaining an analysis process for a point at which a third line segment of the polygon shown in FIG. 5 intersects with a target plane.
Fig. 10 is a view for explaining points where the other polygons in Fig. 5 intersect with the target plane.
FIG. 11 is a view for explaining an intersection line segment for all polygons of the three-dimensional object model of FIG. 3. FIG.
FIG. 12 is a view for explaining the merging state of the intersection lines of FIG. 11. FIG.
13 is a view for explaining closed two-dimensional polygon information generated by a polygon information extraction method of a three-dimensional object model according to an embodiment of the present invention.
Fig. 14 is a plan view of Fig. 13. Fig.

The description of the present invention is merely an example for structural or functional explanation, and the scope of the present invention should not be construed as being limited by the embodiments described in the text. That is, the embodiments are to be construed as being variously embodied and having various forms, so that the scope of the present invention should be understood to include equivalents capable of realizing technical ideas. Also, the purpose or effect of the present invention should not be construed as limiting the scope of the present invention, since it does not mean that a specific embodiment should include all or only such effect.

Meanwhile, the meaning of the terms described in the present invention should be understood as follows.

The terms "first "," second ", and the like are intended to distinguish one element from another, and the scope of the right should not be limited by these terms. For example, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component.

It is to be understood that when an element is referred to as being "connected" to another element, it may be directly connected to the other element, but there may be other elements in between. On the other hand, when an element is referred to as being "directly connected" to another element, it should be understood that there are no other elements in between. On the other hand, other expressions that describe the relationship between components, such as "between" and "between" or "neighboring to" and "directly adjacent to" should be interpreted as well.

It should be understood that the singular " include "or" have "are to be construed as including a stated feature, number, step, operation, component, It is to be understood that the combination is intended to specify that it does not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

In each step, the identification code (e.g., a, b, c, etc.) is used for convenience of explanation, the identification code does not describe the order of each step, Unless otherwise stated, it may occur differently from the stated order. That is, each step may occur in the same order as described, may be performed substantially concurrently, or may be performed in reverse order.

All terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs, unless otherwise defined. Commonly used predefined terms should be interpreted to be consistent with the meanings in the context of the related art and can not be interpreted as having ideal or overly formal meaning unless explicitly defined in the present invention.

1 is a view for explaining a rendering processing apparatus for performing a polygon information extraction method of a three-dimensional object model according to an embodiment of the present invention.

Referring to FIG. 1, the rendering processing apparatus 100 includes a mesh modeling module 110, a vertex module 120, a rendering module 130, a control module 140, and a storage module 150.

The mesh modeling module 110 extracts a plurality of three-dimensional object data existing on the three-dimensional map, and models the triangular polygons for each three-dimensional object data.

 The vertex module 120 extracts and stores vertex information including a spatial coordinate point constituting the shape of the polygon and vertex index information including a sequence necessary for the polygon representation of a vertex through analysis of each polygon.

The rendering module 130 aligns the plurality of polygons based on the vertex index through the vertex module 120, and sequentially renders the plurality of aligned polygons. At this time, the rendering module 130 physically intersects the target plane and the three-dimensional object data in order to extract the vertical section or the horizontal section information as the two-dimensional polygon information based on the target plane of the height designated by the user in the three- And the connection information between these points.

The control module 140 controls operations of the mesh modeling module 110, the vertex module 120, the rendering module 130, and the storage module 150.

The storage module 150 stores three-dimensional object data, polygon information per three-dimensional object data, vertex information, vertex index information, and the like.

Here, each of the modules 110 to 150 may be designed in the form of hardware or software, or may be designed by integrating hardware and software.

2 is a flowchart illustrating a method of extracting polygon information of a three-dimensional object model according to an exemplary embodiment of the present invention. 3 is a view for explaining the shape of the three-dimensional object model of FIG. 2, FIG. 4 is a view for explaining polygon information of the three-dimensional object model of FIG. 3, In which a target plane is disposed.

2 to 5, a polygon information extraction method of a three-dimensional object model includes arranging three-dimensional vertex coordinates forming a shape of a three-dimensional object model 300 on the basis of a vertex index, (S1)

3 and 4, when the 3D object model 300 is a multi-layer building, the 3D object model 300 is a rectangular parallelepiped, and a plurality of 3D polygons 310 It becomes 12 triangles.

The rendering processing apparatus 100 cross-arranges the target plane 320 including the horizontal or vertical cross section of the three-dimensional object model 300 with the three-dimensional object model 300. At this time, The target plane 320 is formed larger than the cross section of the three-dimensional object model 300 as shown in Fig. 5, and is made up of two triangles, in order to obtain the cross-sectional shape based on the desired height or layer in the building.

The rendering processing apparatus 100 extracts intersection information by checking whether an intersection of the 3D polygon 310 is generated based on the target plane 320. At this time, ) And the one side of the three-dimensional polygon 310 intersect with each other.

FIG. 6 is a view for explaining points of intersection between the polygon and the target plane in FIG. 5, FIG. 7 is a view for explaining an analysis process for a point at which a first line segment of the polygon in FIG. 5 is an explanatory view of an analysis process for a point at which the second line segment of the polygon of FIG. 5 intersects with the target plane, FIG. 9 illustrates an analysis process of a point at which the third line segment of the polygon of FIG. And Fig. 10 is a view for explaining points where the other polygons in Fig. 5 intersect with the target plane.

6 to 10, the rendering processing apparatus 100 sets a mesh A 311 composed of vertices of A1, A2, and A3 among a plurality of three-dimensional polygons 310 as a reference three-dimensional polygon, It is checked whether an intersection with the target plane 320 occurs in a predetermined view direction from the 3D polygon to the last 3D polygon.

6, when the intersection of the faces of the mesh A 311 and the target plane 320 intersects with each other and EA1 and EA2 intersect each other, the rendering processing apparatus 100 sets the intersection coordinates of EA1 and EA2 as . That is, as shown in Fig. 7, the intersection coordinates of EA1 are acquired because there is an intersection of EA1 on one side of line A1A3 and target plane 320 of mesh A 311.

Thereafter, as shown in Fig. 8, the intersection coordinates of EA2 are acquired because there is an intersection of EA2 on one side of the line A2A3 of the reference three-dimensional polygon 311 and the target plane 320. [ 9, since there is no intersection between the line A1A2 of the reference three-dimensional polygon 311 and the one side of the target plane 320, the intersection checking process for the three three-dimensional line segments of the reference three-dimensional polygon 311 is terminated do. Accordingly, the rendering processing apparatus 100 can extract the intersection information EA1 and EA2 where the three-dimensional line segment of the mesh A 311 and the target plane 320 intersect.

The rendering processing apparatus 100 generates an intersection with the target plane 320 with respect to the mesh B 312 made up of the three-dimensional polygons B1, B2, and B3 adjacent to the mesh A 311 . Since the intersection of EB1 and EB2 exists between the mesh B 312 and the target plane 320, the intersection coordinates of EB1 and EB2 are acquired.

Referring again to FIG. 2, the rendering processing apparatus 100 analyzes the intersection points of three segments of the mesh A 311, and intersects the plane only when there are two intersection points. Therefore, , And the intersection line segment connecting the start point and the end point is extracted and stored (S4 and S5)

The rendering processing apparatus 100 extracts intersection information by checking whether an intersection has occurred with respect to the twelve three-dimensional polygons 310 constituting the three-dimensional object model 300, and then searches for all intersection segments using the intersection information (S6)

FIG. 11 is a view for explaining an intersection line segment for all polygons of the three-dimensional object model of FIG. 3, and FIG. 12 is a view for explaining a merging state of intersection lines of FIG.

11 and 12, the intersection segment EA1EA2 of the mesh A 311 has EA1 as the start point and EA2 as the end point. Likewise, the intersection line segment EB1EB2 of the mesh B 312 has EB1 as the start point and EB2 as the end point. The mesh C 313 and the mesh D 314 also distinguish the starting points EC1 and ED1 and the end points EC2 and ED2 of the intersection segment EC1EC2 and the intersection segment ED1ED2.

The rendering processing apparatus 100 analyzes the connection relationship between the intersection line segments and searches for intersection lines whose end points of one intersection line segment have the same coordinate value as the starting point of another intersection line segment. (S7) For example, EA2 which is the end point of EA1EA2 and EB1 which is the starting point of the intersection segment EB1EB2 have the same coordinate value. In this way, the connection relation of the intersection line segments to mesh E, mesh F, mesh G, and mesh H is also analyzed to check the connection point (end point-start point) of each intersection line segment.

The rendering processing apparatus 100 determines the starting point (EB1) of the intersection line segment of the mesh B from the end point (EA2) of the intersection segment of the mesh A based on the result of analyzing the connection relationship between the intersection line segments, the end point (EB2 (EC1) of the intersection line segment of the mesh C, the end point (EC2) of the intersection line segment of the mesh C and the starting point ED1 of the intersection segment of the mesh D, the end point ED2 of the intersection segment of the mesh D, Connect the starting point (EE1) of the segment.

In this manner, all intersection lines are merged, and finally, the closed two-dimensional polygon information is calculated by connecting the starting point (EA1) of the intersection line segment of the mesh A and the end point of the intersection line segment of the mesh H (S8 and S9)

FIG. 13 is a view for explaining closed two-dimensional polygon information generated by a polygon information extraction method of a three-dimensional object model according to an embodiment of the present invention, and FIG. 14 is a plan view of FIG.

13 and 14, the rendering processing apparatus 100 identifies an intersection point generated by intersection of faces between all three-dimensional polygons 310 of the three-dimensional object model 300 and the target plane 320, When two intersection points occur in one segment of the dimensional polygon (310), the intersection segment is extracted, and the connection relation of all intersection segment segments is analyzed. Then, the intersection point of the intersection segment and the start point of another intersection segment are merged, Dimensional polygon 330 is obtained.

In other words, the connection relationship of the intersection lines with respect to the mesh A to the mesh H is checked based on the target plane 320, and the connection points EA1-EH2, EB1-EA2, EC1-EB2, ED1-EC2, EE1- -E2, EG1-EF2, and EH1-EG2 are merged to obtain a closed polygon (330).

The closed polygon 330 is two-dimensional shape information that enables a two-dimensional cross-sectional analysis of the three-dimensional object model 300. Since the closed polygon 330 is easier for the user to recognize than a precise and complex three-dimensional shape, it can be utilized as basic data for two-dimensional content authoring.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention as defined by the following claims It can be understood that

110: mesh modeling module 120: vertex module
130: rendering module 140: control module
150: storage module

Claims (5)

A polygon information extraction method of a three-dimensional object model performed by a rendering processing apparatus for expressing a shape of a three-dimensional object model or a two-dimensional object model,
Constructing a plurality of three-dimensional polygons by arranging three-dimensional vertex coordinates forming a shape of the three-dimensional object model on the basis of a vertex index;
Intersecting the three-dimensional object model with a target plane including a horizontal or vertical cross-section of the three-dimensional object model;
Dimensional polygons are generated by extracting intersection information by checking whether an intersection where one surface of a plurality of three-dimensional polygons intersects with the target plane is generated is detected based on the target plane, and when a plurality of intersections occur in the three- Extracting and storing at least one connected intersection segment; And
Dimensional polygon information by analyzing a connection relation of the at least one intersection line segment and merging the intersection line segments according to the analyzed connection relationship. A method for extracting polygon information of a model.
The method according to claim 1,
Wherein the target plane is composed of a plurality of polygons and is formed to be larger than a cross section of the three-dimensional object model.
The method according to claim 1,
Dimensional polygons are generated by extracting intersection information by checking whether an intersection where one surface of a plurality of three-dimensional polygons intersects with the target plane is generated is detected based on the target plane, and when a plurality of intersections occur in the three- The step of extracting and storing at least one intersection line segment,
Extracting coordinates of the intersection points by line segments of the three-dimensional polygon and storing the coordinates as intersection information; And
Dimensional polygon, two intersecting points are set as a starting point and an ending point when two intersecting points exist in the three-dimensional polygon, and an intersecting line segment connecting the starting point and the ending point is extracted and stored for each line segment of the three-dimensional polygon And extracting the polygon information of the three-dimensional object model.
The method of claim 3,
The step of analyzing the connection relation of the at least one intersection line segment and constructing the closed two-dimensional polygon information by merging the intersection line segments according to the analyzed connection relation,
Identifying an intersection line segment having an end point of the intersection line segment and a start point of another intersection line segment having the same coordinate value, and confirming a connection relationship; And
Constructing coordinates of a closed two-dimensional polygonal space by linking all intersection lines extracted and stored for each line segment of the three-dimensional polygon in such a manner that the end points having the same coordinate value and the starting point are mutually merged; And extracting the polygon information of the three-dimensional object model.
The method according to claim 1,
Wherein the closed-form two-dimensional polygon information is two-dimensional shape information of a vertical section or a horizontal section of the three-dimensional object model.

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