JP6124109B2 - Generating the entire shape of an object from partial points and line shapes - Google Patents

Description

Detailed Description of the Invention

  This invention is a shape called an irregular triangle network that represents the entire shape of an object as a set of irregular triangles from the points and lines that represent the slope change part that is the feature of the object, and is used for spatial analysis and design by computer software The present invention relates to a technique for automatically generating a model.

  The irregular triangle network used for spatial analysis and design is used by computer software such as GIS (Geographic Information System) and CAD (Computer Assisted Design).

  However, in the conventional technique, since the irregular triangular network is created from the point cloud, the slope conversion point that is the feature of the object cannot be expressed, and a smooth shape model is obtained.

  In order to obtain object features, breaklines that represent slope transformation points as lines are used to give object features to smoothed shape models. However, object features can only be found around breaklines. I can't catch it.

Problems to be solved by the invention

  In the conventional technology, in order to model the entire shape of an object, it is basic to use point clouds, and if necessary, the features of the object are given to the shape model as breaklines and the shape model is corrected. In other words, it was insufficient to accurately represent the characteristics of the object.

  An object of the present invention is to eliminate such inconveniences and generate a shape model that accurately represents the characteristics of an object as an irregularly shaped triangular network.

Means for solving the problem

In order to achieve these objects, the present invention is a method for generating the entire shape of an object specified by the configurations of the following items (1) to (6) from partial points and line shapes.
(1) This is a method of generating a whole shape of an object from these points and lines, with a graphic database storing points and lines representing a tilt change part as a feature of the object being stored.
(2) In the graphic database, a triangle that is not a vertex of a triangle that has already been created is a vertex, a triangle that does not include other points, does not intersect with other lines, and has a base line around it. Generate a shape.
(3) On each side of the generated triangle, the side that does not match the line existing in the graphic database is added to the graphic database.
(4) In the graphic database, a line that is not a triangle side already created is the base, does not contain other points, does not intersect with other lines, Generates a triangle whose vertex is an existing line node.
(5) On each side of the generated triangle, the side that does not match the line existing in the graphic database is added to the graphic database.
(6) Repeat (2) to (5) until all the points and lines in the graphic database are the vertices or sides of the triangle.

The actual state of the invention

  Hereinafter, a method of automatically generating a shape model called an irregularly shaped triangular network that expresses the entire shape of an object as a set of irregularly shaped triangles from the points and lines that represent the slope conversion unit, which is a feature of the aforementioned object, An embodiment will be described as an example applied to map data creation.

  The points and lines to be processed in this embodiment are the figures edited in the aerial photogrammetry while maintaining the height information drawn from the stereoscopic aerial photo using the plotter and maintaining the height information. is there.

=== Generation of triangles from points ===
In generating a triangle from a point, for example, in FIG. 1, an arbitrary point P1 is extracted from the graphic database. Next, a line composed of nodes L1p1 to L1p4 around the point P1, a line composed of nodes L2p1 to L2p3, a line composed of nodes L3p1 to L3p3, a line composed of nodes L4p1 and L4p2, and a node L5p1 A line composed of L5p4 is taken out.

  In FIG. 2, line segments P1-L1p1, P1-L1p2, P1-L1p3, P1-L1p4, P1-L3p1, P1 which are sides of a triangle from an arbitrary point P1 to a node where no intersection with another line segment occurs. -L3p2, P1-L3p3, P1-L5p1, P1-L5p2, P1-L5p3, P1-L5p4 are generated.

  In FIG. 3, the line segments P1-L1p1, P1-L1p2, P1-L1p3, P1-L1p4, P1-L3p1, P1-L3p2, P1-L3p3, P1-L5p1, P1-L5p2, P1 that are the sides of the generated triangle From -L5p3, P1-L5p4, triangles T1 to T11 are generated in the order of surrounding an arbitrary point P1.

  In FIG. 4, among the generated triangles T1 to T11, for example, triangles T1, T7 to T9, and T11 which are triangles with long sides that lose terrain features such as undulating terrain or flat terrain. Remove.

=== Generating a triangle from a line ===
In generating a triangle from a line, for example, in FIG. 5, an arbitrary line M1 is extracted from the graphic database. Next, lines M2, M3, M4, and M5 having nodes on the right side of the line M1 are taken out.

  In FIG. 6, the other nodes M1p1, M1p4 on the right side of the line segment M1p2-M1p3 extending infinitely from the nodes M1p2 and M1p3 of the line segment M1p2-M1p3 on the leftmost side in the line M1. , M1p5, M2p1 to M2p3, M3p1 and M3p2, M4p1, and M5p1 to M5p3 are generated as line segments.

  In FIG. 7, the line segments generated from the nodes M1p2 and M1p3 overlap the line segments constituting the lines M1 to M5 taken from the graphic database, or intersect line segments M1p2-M1p1, M1p2-M2p3, Remove M1p2-M5p3, M1p2-M5p2, M1p2-M5p1, M1p2-M1p5, M1p2-M4p1, and M1p3-M1p4.

  In FIG. 8, line segments M1p3-M2p3, M1p3-M5p3, M1p3-M5p2, M1p3-M5p1, M1p3-M1p5, and M1p3-M4p1 connected to the nodes that constitute the line segment only from one of the nodes M1p2 and M1p3 are removed. .

  In FIG. 9, triangles T12 to T17 are created, each of which includes line segments M1p2 to M1p3 as bases and is composed of nodes to which line segments from both nodes M1p2 and M1p3 are connected.

  In FIG. 10, among the created triangles T12 to T17, the triangle T14 having the largest vertex angle with the line segment M1p2-M1p3 as the base is the object part on the right side of the line segment M1p2-M1p3. Let it be a triangle representing the shape.

=== Generation of object shape model ===
By generating triangles from points and triangles from lines, all points and lines in the graphic database are comprehensively generated in the area where points and lines exist, so-called map creation, A terrain model that is an element of map representation is generated as an irregular triangle network.

Effect of the invention

  As described above, in the present invention, since the entire shape of the object can be expressed from points or lines representing a part of the object, it is not necessary to create data for expressing the entire shape of the object again. .

  In addition, since the overall shape of the object is expressed using points and lines that capture the feature of the object, the overall shape of the created object retains the feature of the object.

  As described above, according to the present invention, the efficiency of creating the entire shape of the object from a part of the object can be achieved, and the quality retaining the characteristics of the object can be ensured.

  It is the figure which expressed the edge of one side of the road edge and the road periphery surrounding a road including a point in a road, and a surrounding.   It is the figure which produced | generated the line by selecting only the thing which does not cross | intersect the line in a graphic database from the point in a road to the node of the line in the periphery.   It is the figure which produced | generated the triangle which made the line segment in a graphic database the base, and made the generated line the other side of a triangle.   It is a figure showing having extracted only the triangle which has all the vertices of the triangle in the vicinity from the produced | generated triangle.   It is the figure showing the ridge line and valley line which become the topography of the topography.   It is the figure which generate | occur | produced the line with respect to the node of the line segment in the one side from the node of the both ends of a specific line segment.   It is the figure which extracted only the line segment which does not cross the line in a graphic database from the generated line segment.   It is the figure which left only the line segment which makes a specific line segment a base and can comprise a triangle.   It is the figure which produced | generated the triangle with the specific line segment as the base and the remaining line segment.   It is the figure which left the triangle of the vertex which becomes the largest angle when a specific line segment is made into a base from the generated triangle.

P1 Points L1, L3, L5 Line L2 representing road edge Line L2 representing edge of slope surface Line L1p1 to L1p4 representing encircling Node L2p1 to L2p3 composing line L1 Nodes L3p1 to L3p3 composing line L2 Nodes L4p1 and L4p2 constituting the nodes L5p1 to L5p4 constituting the line L4 Nodes T1 to T11 constituting the line L5 Triangles M1 to M5 generated from the point P1 Lines M1p1 to M1p5 Nodes M2p1 constituting the feature of the line M1 ~ M2p3 Nodes M3p1 to M3p2 constituting the line M2 Nodes M4p1 to M4p2 constituting the line M3 Nodes M5p1 to M5p3 constituting the line M4 Nodes T12 to T16 constituting the line M5 A triangle generated with the line segment M1p2-M1p3 as the base

Claims (2)

A method of automatically generating the entire shape of an object specified by the configuration of the following items (1) to (6) from a partial point or line shape by computer processing .
(1) A method is a method in which a graphic database storing points and lines representing a slope changing portion that is a feature of an object is a processing target, and the entire shape of the object is automatically generated from these points and lines by computer processing. .
(2) In the graphic database, a point that is not a vertex of a triangle that has already been created is taken as a pair of vertices, does not include other points, and does not intersect with any line segment that constitutes that line on another line Then, a triangle is generated with the line segment that is most directly facing the opposite vertex among the line segments that form the line existing around the base.
(3) on each side of the generated triangle, the sides do not match the line segments existing in the graphic database is added to the graphic database.
(4) in the graphic database, already the bottom of the line segments that do not become the sides of a triangle that is created and does not contain any other point, not intersect any of line segments constituting the other line, the peripheral there point and which generates a triangle having the node pair vertices of lines existing in the vicinity.
(5) On each side of the generated triangle, an edge that does not match any line segment that forms a line existing in the graphic database is added to the graphic database.
(6) all the segments that make up all the points and lines of the graphic in the database, until a pair of triangle vertices or edges, repeating (5) (2). In claim 1, the lines in the figure, already the bottom lines fraction not the sides of a triangle, the point and that exists in the vicinity, and generates a triangle whose vertices are the nodes of the line present in the neighborhood, a triangle each side not intersect any of line segments constituting the lines in the figure, triangle triangular free points in the figure, the largest triangular angle of opposite vertexes of the triangle base of the object shape one A method of automatically generating a triangle as a part by computer processing .

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