JP5039978B1 - 3D graphics calculation program, dynamic link library, and landscape examination device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform a highly accurate figure calculation while suppressing an increase in data amount in a figure calculation for generating a composite screen of each three-dimensional figure based on an interstitial relationship of a plurality of three-dimensional figures. Provided is a landscape examination device that executes a computation program, a dynamic link library, and a three-dimensional graphic computation program to study a landscape.
A three-dimensional figure calculation program includes a first step of expressing each three-dimensional figure as a polyhedron, and other three-dimensional figures related to all the faces constituting one three-dimensional figure expressed in the polyhedron. The second step of analyzing the interpenetration relationship of all the constituent surfaces, and the part that overlaps with the other three-dimensional graphics on the backside of each surface composing one three-dimensional graphic based on the analysis result of this interpenetration relationship The computer is caused to execute a third step of removing and a fourth step of synthesizing and displaying three-dimensional figures composed of surfaces having portions that have not been removed.
[Selection] Figure 2

Description

  The present invention relates to a three-dimensional graphic calculation program, a dynamic link library, and a landscape examination apparatus that analyze the intermeshing relationship of a plurality of three-dimensional figures in a three-dimensional space and perform composite display of each three-dimensional figure. It relates to technology that generates and displays a composite screen of topography and structures using a program, and simulates and examines the landscape.

  Conventionally, in construction projects, structures such as buildings and road surfaces are prepared as three-dimensional data, and the contents of the construction plan are three-dimensionally represented in a three-dimensional space by synthesizing with three-dimensional data of background photos and topography. A landscape simulation system that can be confirmed is known. In this system, in the process of creating a composite screen used for landscape examination, the overlap (interpenetration relationship) between the topography and the structure in the three-dimensional space is analyzed, and the respective overlapping portions are removed, and then each of them is removed. We are doing synthesis. In other words, a part of features such as existing terrain is notched, and a new civil engineering building facility is added to the part where the notch is applied. Is displayed.

  In the initial landscape simulation system, graphic operations based on the interpenetration relationship between terrain and structures (especially slopes) were executed using a depth buffer used for hidden line removal in the drawing process. In other words, after dividing the top view of the terrain and structure into meshes corresponding to the resolution of the display screen, it is determined whether the terrain or structure is above each lattice point, and the terrain obtained from this determination result And the intersection of the structure. Then, based on this intersecting figure (two-dimensional closed polygon projected on the horizontal plane), the range of the terrain to be deleted and the shape of the slope to be filled there are obtained and synthesized. It was.

  However, the shape of the intersection between the terrain and the structure obtained by this method is limited by the resolution of the depth buffer specified by the screen size, and the straight line portion is not a simple straight line but is obtained as a broken line. The For this reason, although the data becomes unnecessarily large, the accuracy of the calculation result is low, a gap is generated between the terrain and the structure, or the polygons that make up the surface of the terrain and structure near the boundary. There were problems such as loss of flatness. In addition, although it can be used as a distant view for studying a long slope, there is a limit to the quality of a landscape image from a close viewpoint position such as a vehicle occupant traveling on the road.

  As a technique for solving this problem, a three-dimensional figure calculation method using triangulation has been proposed (see Non-Patent Document 1). According to this method, the terrain or structure represented by three-dimensional data is represented as a shape (polygon) that approximates a polyhedron, and the complex polygons that form the surface are divided into triangles in advance. Then, by performing notch processing between the respective triangles at the intersection between the terrain and the structure, the case classification of the processing is simplified, and it is possible to perform exact coordinate calculation.

"Architecture Research Document No.96 Mature City Simulator Ver1.0 + Landscape Simulator Ver2.05 Practical Manual" Architectural Institute, Ministry of Construction, July 2000

  However, in the above-described graphic calculation by triangulation, even if simple triangle notch processing is performed, the processing result has a complicated shape, and further triangulation is required prior to the next processing. For this reason, there is a problem that as the processing proceeds, the terrain is complicated and subdivided and the amount of data is enlarged. In addition, since the topography is complicated and subdivided, the calculation success rate is low, and it cannot be said that the calculation method is accurate.

  The present invention has been made to solve such a problem, and suppresses an increase in the amount of data in a graphic operation for generating a composite screen of each three-dimensional figure based on the interstitial relationship of a plurality of three-dimensional figures. An object of the present invention is to provide a landscape examination apparatus that examines a landscape by executing a three-dimensional graphic calculation program, a dynamic link library, and a three-dimensional graphic calculation program capable of performing high-precision graphic calculation.

In order to achieve the above object, the invention according to claim 1 analyzes the interplay relation of a plurality of three-dimensional figures in a three-dimensional space, and removes overlapping portions to synthesize and display each three-dimensional figure. A first step of expressing each of the three-dimensional figures in a shape that approximates a polyhedron that is a set of faces, and each of the three-dimensional figures that are expressed in a shape that approximates a polyhedron in the first step In the three-dimensional figure, the second step for analyzing the interpenetration relationship of all the faces constituting the other three-dimensional figure with respect to all the faces constituting the one three-dimensional figure, and the phase of the faces in the second step Based on the results of the analysis of the interstitial relationship, a third step of removing a portion that overlaps with the other three-dimensional figure on each side constituting one three-dimensional figure, and is not removed in the third step. A fourth step of displaying by synthesizing three-dimensional figure which can produce a surface having a portion Tsu, have, and the analysis phase transmural relationship faces thereof in the second step, constituting one of the three-dimensional figure When the notch of one surface starts from the side or vertex of the other surface and ends inside the other surface A cut-in step for performing the above process, a cut-out step for performing a process when a notch by one surface starts from the inside of the other surface and ends at an edge or vertex of the other surface, and a notch by the one surface After the division, when the other surface is divided into multiple pieces by the notch step that performs processing when starting from the inside of the other surface and ending inside the other surface and the notch by one surface A cut to determine the front and back of the split surface of each piece of It has a step, and is characterized in that to execute the respective steps in a computer.

The invention according to claim 2, in three-dimensional figure computation program according to claim 1, of each face of the three-dimensional figure expressed in a shape approximated to a polyhedron in a first step, a hole inside surface The method further comprises a sub-step of connecting any vertex constituting the hole and any vertex constituting the surface having the hole with a virtual line.

According to a third aspect of the present invention, in the three-dimensional graphic calculation program according to the first or second aspect, one end of the cut is formed on a surface where a linear cut having no area is generated in the surface in the cutting step. And a sub-step of connecting any one of the vertices constituting the cut surface with a virtual line.

The invention according to claim 4 is the three-dimensional graphic operation program according to claim 2 or 3 , in the case where a new notch due to another surface occurs in the second step for the surface having the virtual line, The method further includes a sub-step of deleting the virtual line or changing the connection destination according to the occurrence of the new notch.

According to a fifth aspect of the present invention, in the three-dimensional graphic operation program according to any one of the second to fourth aspects, the virtual line can be set to non-display at the time of composite display in the fourth step. And

According to a sixth aspect of the present invention, in the three-dimensional graphic calculation program according to any one of the first to fifth aspects, each surface of the three-dimensional graphic expressed in a shape approximated to a polyhedron in the first step is It is further characterized by further including a sub-step of determining whether the process after the second step is normal or abnormal as a target to which the process is applied, and correcting the surface determined to be abnormal.

According to a seventh aspect of the present invention, in the three-dimensional figure calculation program according to any one of the first to sixth aspects of the present invention, an analysis error is caused as a result of analyzing the interpenetration relationship between the surfaces in the second step. The method further includes a sub-step of recording the combination as an error log in the recording unit.

The invention described in claim 8 is a dynamic link library that is loaded and executed on a memory, and includes the three-dimensional graphic operation program according to any one of claims 1 to 7. .

The invention according to claim 9 is a landscape examination device that analyzes three-dimensional data of terrain or a structure, displays a composite screen of the terrain or structure in a three-dimensional space, and simulates and examines the landscape. 8. An input means for inputting the three-dimensional data of the terrain or structure, a recording means for recording the input three-dimensional data, and a three-dimensional graphic calculation program according to any one of claims 1 to 7. Storage means; control means for executing the three-dimensional graphic operation program stored in the storage means to generate the composite screen based on the three-dimensional data of the topography or structure; and displaying the generated composite screen Display means.

The invention described in claim 10 is the landscape examination apparatus according to claim 9 , wherein the imaging means for acquiring the imaging data of the terrain or the structure and the communication for receiving the imaging data acquired by the imaging means And an interface.

The present invention is as described above. According to the first aspect of the present invention, the analysis of the interpenetration relationship of a plurality of three-dimensional figures in the three-dimensional space is performed by comparing the phases of the surfaces constituting each three-dimensional figure. It can be reduced to an analysis of ties. As a result, the graphic calculation between the three-dimensional graphics is simplified, and the graphic calculation with high accuracy can be performed while suppressing an increase in the data amount.
Further, the analysis of the interpenetration relationship between the surfaces is divided into four processing steps according to the state of occurrence of the notch. Thereby, an appropriate processing step according to the notch occurrence state is selected, and the interpenetration relationship between the faces can be accurately analyzed.

According to the second aspect of the present invention, by applying imaginary lines to the surfaces having holes in the surfaces constituting the polyhedron, these surfaces can be handled as quasi-normal surfaces. it can. Thereby, even if it is a surface which has a hole inside, it can analyze the interpenetration relationship between surfaces similarly to a normal surface, without dividing | segmenting a figure.

According to the third aspect of the present invention, in the analysis of the interpenetration relationship between the surfaces, these surfaces can be obtained by applying virtual lines to the surface in which a linear break having no area is generated. It can be treated as a quasi-normal surface. Thereby, even if it is the surface where the linear cut | interruption without an area produced inside, it can analyze the interpenetration relationship between surfaces similarly to a normal surface, without dividing | segmenting a figure.

According to the fourth aspect of the present invention, when a new notch is generated on a quasi-normal surface having a virtual line, the virtual line is deleted or connected according to the occurrence of the new notch. Changes are made. As a result, the virtual line is always properly applied to the quasi-normal surface, and the analysis can be accurately performed even in the analysis of continuous surfaces.

According to the fifth aspect of the present invention, the virtual line can be set to non-display when the result of the graphic calculation is displayed. Thereby, a display screen with less noise can be obtained, and the shape of the figure after the figure calculation can be displayed in an easy-to-understand manner.

According to the invention described in claim 6 , prior to the analysis of the interpenetration relationship between the surfaces, the surface in which an abnormality is detected among the surfaces to be analyzed is appropriately corrected. As a result, it is possible to reduce the rate at which analysis errors due to surface anomalies occur.

According to the seventh aspect of the present invention, in the analysis of the interpenetration relationship between the surfaces, the combination of the surfaces in which an analysis error has occurred is recorded as an error log. As a result, it is possible to easily identify the location where an analysis error has occurred in the analysis of the inheritance relationship, and the maintainability of the program is improved in this respect.

According to the invention described in claim 8 , by providing the three-dimensional graphic operation program as a dynamic link library, it is possible to make corrections and updates independently without affecting other programs. Maintainability is improved. In addition, it is possible to provide the 3D graphic operation function realized by this 3D graphic operation program as an independent function, and the application range can be expanded.

According to the invention described in claim 9 , the effects described in any one of claims 1 to 7 can also be achieved in the landscape examination device. Thereby, when displaying the composite screen of the terrain or the structure in the three-dimensional space, it is possible to display a screen that is smoothly combined without an extra gap at the boundary portion.

According to the tenth aspect of the present invention, it is possible to receive from the imaging means the imaging data of the topography or the structure imaged by the imaging means such as a camera. Thereby, the landscape can be examined not only from the three-dimensional data input by the input means but also from the data imaged by the imaging means.

It is a block diagram which shows the structural example of the landscape examination apparatus which concerns on one embodiment of this invention. It is a flowchart which shows the whole process of the figure calculation performed by the three-dimensional figure calculation program same as the above. It is explanatory drawing which shows the example which applied the virtual line to the perforated surface same as the above. It is a flowchart which shows the whole process of the analysis of the mutual relationship of the surfaces performed by the three-dimensional figure calculation program same as the above. It is a flowchart which shows the notch process of the surface F1 by the surface F2 same as the above. It is explanatory drawing which shows the outline | summary of "cutting" same as the above. It is explanatory drawing which shows the example of the vertex addition in "cutting" same as the above. It is a flowchart which shows the flow of a cutting process same as the above. It is explanatory drawing which shows the outline | summary of "cutout" same as the above. It is a flowchart which shows the flow of a cut-out process same as the above. It is explanatory drawing which shows the outline | summary of "cutting" same as the above. It is explanatory drawing which shows the example of application of the virtual line in "cutting" same as the above. It is a flowchart which shows the flow of a cutting process same as the above. It is explanatory drawing which shows the outline | summary of "cutting" same as the above. It is explanatory drawing which shows the example of the vertex addition in "Cut" same as the above. It is a flowchart which shows the flow of a separation process same as the above. It is explanatory drawing which shows the mode of the deletion of the virtual line according to the generation | occurrence | production situation of the same as the above, or the change to a normal side. It is explanatory drawing which shows the mode of the deletion of the virtual line according to the generation | occurrence | production situation of the same as the above, or the change to a normal side. It is explanatory drawing which shows the mode of a change of the connection destination of a virtual line according to the generation | occurrence | production state of a notch same as the above. It is explanatory drawing which shows the mode of a change of the connection destination of a virtual line according to the generation | occurrence | production state of a notch same as the above. It is explanatory drawing which shows the example of the synthetic | combination screen of the topography and structure displayed by a landscape examination apparatus same as the above.

  In the three-dimensional figure calculation program according to one embodiment of the present invention, when analyzing the interpenetration relationship of a plurality of three-dimensional figures in a three-dimensional space, first, a shape (polygon) approximating each three-dimensional figure to a polyhedron Express as Then, the interpenetration relationship is sequentially analyzed between all the surfaces constituting one three-dimensional figure and all the faces constituting another three-dimensional figure. The analysis of the interpenetration relationship between the surfaces is performed based on a notch state generated between the surfaces, and a predetermined notch process corresponding to the notch state is performed. In this way, the processing is simplified by reducing the analysis of the interstitial relationship in a plurality of three-dimensional figures to the repetition of notch processing between faces.

In addition, when each three-dimensional figure is expressed as a polyhedron, if a surface with a hole is generated inside it, these surfaces are quasi-normal surfaces by applying virtual lines to this surface. It is possible to apply a notch treatment in the same way as a normal surface. This imaginary line is also applied to a surface where a linear cut is generated in the process of notching between the surfaces, and these surfaces are also treated as “quasi-normal surfaces”. Yes.
Hereinafter, specific processing contents of the three-dimensional figure calculation program will be described with reference to the drawings. Here, a description will be given by taking as an example a landscape examination device that executes this three-dimensional figure calculation program, displays a composite screen of terrain or a structure, and examines the landscape.

  In FIG. 1, 1 is a landscape examination device, and this landscape examination device 1 has a composite screen of structures such as buildings and road surfaces prepared in advance as three-dimensional data, and background photos and landforms similarly prepared. The main basic function is to display and confirm the state of synthesis in a three-dimensional space in a three-dimensional manner. In addition, it also has a function of providing various editing screens necessary for displaying the composite screen.

  The landscape examination device 1 has a general personal computer PC. That is, the PC includes a control unit (CPU: Central Process Unit) 2 that controls the entire apparatus and graphic operations, a rewritable RAM (Random Access Memory) 3 that temporarily stores processing data of the control unit 2, and fixed data. ROM (Read Only Memory) 4 that stores data, recording means 5 such as a hard disk drive device that records data of graphic calculation results, etc., input means 6 such as a keyboard and mouse for inputting various data and instructions, graphic calculation results The computer includes hardware resources such as a display unit 7 such as a display and a communication interface 8 used for network connection. And the basic function of the scenery examination apparatus 1 is implement | achieved by cooperation with each hardware resource and software including a three-dimensional figure calculation program.

  Moreover, this landscape examination apparatus 1 may be provided with an image pickup means 9 that takes an image of the terrain or structure that is the object of landscape examination. This imaging means 9 is composed of, for example, a digital camera or the like, and the landscape can be examined using the imaging data of the topography and structures acquired by the imaging means 9.

  The imaging data acquired by the imaging means 9 can be transmitted to the landscape examination device 1 via the communication interface 8. As described above, the imaging data input from the imaging unit 9 includes, for example, a stereo photograph taken from the viewpoint positions of a plurality of different cameras or a monocular taken by a normal method in order to view the terrain and structures in three dimensions. Examples include photos. Imaging data such as a stereo photograph input in this way is converted into three-dimensional data to be input to a three-dimensional graphic calculation program, and graphic calculation is performed using the three-dimensional data.

  In addition, as the three-dimensional data input to the three-dimensional graphic calculation program as input data, the three-dimensional data previously created by CAD (Computer Aided Design) or GIS (Geographic Information System) is suitable for graphic calculation. Data converted into a data format or data created as three-dimensional data by the operator using the input means 6 based on a paper drawing created in the past may be used. The three-dimensional data created by these methods and the three-dimensional data generated from the imaging data by the imaging means 9 are recorded in the recording means 5 such as a hard disk drive device.

  As described above, after the three-dimensional data to be input to the three-dimensional graphic calculation program is prepared, the operator operates the input means 6 such as a mouse to instruct the start of graphic calculation. Upon receiving this instruction, the control means 2 reads a three-dimensional graphic calculation program stored in advance in the ROM 4 and executes it to start graphic calculation. The three-dimensional figure calculation program may be installed from an external recording medium such as a CD-ROM and recorded in the recording means 5 such as a hard disk drive device. Hereinafter, the graphic calculation executed by the control means 2 will be described in detail with reference to FIGS.

<Overall flow>
FIG. 2 is a flowchart showing an overall flow of graphic calculation executed by the control means 2. First, the overall flow of graphic computation will be described based on this flowchart, and then the specific processing contents in each step will be described.

As shown in FIG. 2, the graphic calculation is mainly composed of four processing steps. The outline of the processing of each step is shown below.
(Step 01) Based on the input three-dimensional data such as terrain and structure, each three-dimensional figure is expressed in a shape (polygon) approximating a polyhedron.
(Step 02) In step 01, in each three-dimensional figure expressed in a shape approximated to a polyhedron, all the faces constituting another three-dimensional figure are related to all the faces constituting one three-dimensional figure. Analyze the relationship.
(Step 03) On the basis of the analysis result of the interpenetration relationship between the surfaces in Step 02, a portion which overlaps with another three-dimensional figure on each surface and becomes the back side is removed.
(Step 04) In step 03, three-dimensional figures composed of surfaces having portions that have not been removed are synthesized with each other, and a synthesized screen is displayed.
Hereinafter, each of these steps will be described in detail.

<Step 01: Approximating a polyhedron>
First, the control means 2 reads out three-dimensional data of a figure such as a structure that has been instructed by the operator and subjected to a figure calculation from the recording means 5. Based on the read three-dimensional data, each three-dimensional figure is expressed as a shape (polygon) approximated to a polyhedron. And in each surface which comprises each three-dimensional figure expressed in this way, when the surface which has a hole in the inside (henceforth a perforated surface) arises, a virtual line with respect to this perforated surface Apply.

  This imaginary line can be handled in the same way as a normal surface without a hole even if it has a hole inside such as the perforated surface described above. Even a three-dimensional figure with a hole inside, such as terrain on which figure calculation is performed, can be handled in the same way as a normal three-dimensional figure.

  A specific application example of virtual lines is shown in FIG. In this example, in the holed surface 10 having the hole 11 therein, any vertex constituting the hole 11 and any vertex (vertex 12 in this case) constituting the holed surface 10 are represented by virtual lines. Connect with K. In this way, by connecting the hole 11 and the vertex 12 with the virtual line K, the perforated surface 10 can be used in the processes after step 02 without dividing the figure as in the conventional triangulation. The specific action of the virtual line K will be described in step 02 described later.

  The control means 2 stores in the RAM 3 data relating to all the faces of the three-dimensional figure expressed as a polyhedron. These data may be recorded in the recording means 5 such as a hard disk drive device.

<Step 02: Analysis of mutual relationship between faces>
Next, in each three-dimensional figure expressed as a polyhedron in step 01, the control means 2 relates to all the faces constituting one three-dimensional figure and all the faces constituting the other three-dimensional figure. Analyze. This step 02 comprises sub-steps 11 to 17 shown in the flowchart of FIG. Here, in order to simplify the description, each sub-step will be described based on the flowchart of FIG. 4 using two three-dimensional figures G1 and G2 as an example.

  First, in the two three-dimensional figures G1 and G2, the parts included in the figure G2 are considered with respect to all the surfaces constituting the figure G1. Such a portion is a portion that overlaps the graphic G2 and becomes the back side of the G2, and is a portion to be removed. Therefore, removing all portions included in the figure G2 for all the surfaces constituting the figure G1 is referred to as "cutting G1 with G2."

  In this way, when G1 is cut out by G2, the faces constituting G1 are cut out by G2 independently of each other without being affected by each other. That is, when a portion included in G2 is cut out with respect to one face F1 constituting G1, the face other than F1 constituting G1 is not affected in the same cutout. Therefore, cutting out a portion included in G2 from one surface F1 constituting G1 is referred to as “cutting F1 with G2.” Therefore, first, one surface F1 is extracted from the figure G1 (substep 11).

In order to cut out the surface F1 taken out in this way with G2, it is necessary to cut out the surface F1 with all the surfaces constituting G2. Then, next, one surface F2 is taken out from the figure G2 (substep 12).
Cutting the surface F1 with the surface F2 thus taken out is referred to as “cutting F1 with F2.” Further, the processing performed at that time is referred to as “F1 notch processing by F2” (sub-step 13). Hereinafter, the notch process of the surface F1 by the surface F2 will be described.

<Sub-step 13: Notch processing of the surface F1 by the surface F2>
Sub-step 13 for performing this notch processing further includes sub-steps 21 to 38 shown in the flowchart of FIG. The processing of each sub-step will be described based on the flowchart of FIG.

First, it is determined whether the surface F1 and the surface F2 are normal or abnormal as a target to which the notch processing is applied (substep 21). That is, the surface to which the notch process is to be applied is not necessarily a geometrical surface that may actually exist. For example, it is a face with insufficient vertices having only 2 or less vertices, or a face having a certain side and the next side on a straight line. Such a surface is an inappropriate surface for the notch processing.
Therefore, prior to the processing, the target surface is diagnosed, and if it is determined to be abnormal, the processing is performed after correcting as much as possible. Such diagnosis and correction can be performed not only on the surface before the notch processing but also on the surface obtained as a result of the notch processing.

  Next, it is confirmed whether or not the surface F1 and the surface F2 are the same plane (substep 22). If they are on the same plane, a conventional two-dimensional figure calculation process is performed (substep 23). If not in the same plane, go to substep 24.

  Next, the height of each vertex of the surface F2 with respect to the surface F1 is obtained. Then, it is confirmed whether all the vertices of the surface F2 are above or below the surface F1 (sub-step 24). If all the vertices of the surface F2 are above or below the surface F1, it is determined that the two surfaces do not contact (substep 26), and the substep 13 is terminated. Otherwise, go to substep 25.

  Next, the height of each vertex of the surface F1 with respect to the surface F2 is obtained. Then, it is confirmed whether or not all the vertices of the surface F1 are above or below the surface F2 (substep 25). If all the vertices of the surface F1 are above or below the surface F2, it is determined that the two surfaces do not contact (substep 26), and the substep 13 is terminated. Otherwise, go to substep 27.

  Next, a straight line (intersection line) that is an intersection line of the surface F1 and the surface F2 is obtained (substep 27). Then, intersections between this intersection line and all sides of the face F1 and the face F2 are obtained, and a list of the intersections is created (substep 28). In this list, the intersections are rearranged based on the one-dimensional coordinate values along the intersection line. At this time, when the surface F1 includes a virtual line, the intersections of the virtual line and the intersection line are similarly listed.

  Next, the start point and end point of the notch of the surface F1 by the surface F2 are obtained based on the above list (substep 29). Specifically, on the aforementioned intersection line, each section divided by intersections other than virtual lines is evaluated in ascending order of one-dimensional coordinate values. As a result, all the sections included in the plane F1 and also included in the plane F2 are sections where the cutout is actually performed. That is, the start point and end point of each section become the start point and end point of each notch. Note that the intersections of the virtual lines are listed as attributes of the section.

  Next, based on the notch start and end points obtained in sub-step 29, the notch processing is classified. That is, the notch processing of the surface F1 by the surface F2 is performed in four patterns of “cutting”, “cutout”, “cutting”, and “cutting” according to the positions of the notch start point and end point on the surface F1. Divided. Therefore, it is sequentially confirmed which pattern the notch of the surface F1 by the surface F2 corresponds to.

  First, it is confirmed whether or not the notch is a “cut” (substep 30). The “cut” is a state in which the notch starts from the side or vertex of the surface F1 and ends inside the surface F1. If the cut corresponds to this “cut”, the process proceeds to sub-step 31 to perform a cut process. If not, go to substep 32.

  Next, it is confirmed whether or not the cutout is “cutout” (substep 32). “Cutout” is a state in which the notch starts from the inside of the surface F1 and ends at the side or vertex of the surface F1. When the cutout corresponds to this “cutout”, the process proceeds to sub-step 33 to perform cutout processing. If not, go to substep 34.

  Next, it is confirmed whether or not the notch is “cut” (substep 34). The “notch” is a state in which the notch starts from the inside of the surface F1 and ends inside. If the notch corresponds to this “cut”, the process proceeds to sub-step 35 to perform a cut process. If not, go to substep 36.

  Next, it is confirmed whether or not the cutout is “cutting” (substep 36). “Cutting” is a state in which the start point and the end point of the notch coincide with the side or vertex of the face F1. If the notch corresponds to this “cutting”, the process proceeds to sub-step 37 to perform the cutting process. If not, go to substep 38.

  If the cutout does not correspond to any of the above four patterns, an error message notifying that the cutting method is unknown is output (substep 38), and substep 13 is terminated. Subsequently, specific processing of the above-described four patterns will be described.

<Sub-step 31: Cutting process>
First, the cutting process will be described with reference to FIGS. 6 and 7. FIG. 6A shows a specific example in which this cutting process is performed. As shown in FIG. 6A, in the “cutting”, the notch start point S coincides with the side or vertex of the surface F1, and the end point E is located inside the surface F1. In this case, as a result, the surface F1 straddles the front and back of the surface F2, and the inside / outside determination regarding the graphic G2 of the surface F1 is unknown.

  As shown in the flowchart of FIG. 7, the sub-step 31 that performs the cutting process includes sub-steps 41 to 44. First, in substep 41, the validity of the notch starting point S is checked. Specifically, when the start point S is a start point of a cut created in the past, two sides or vertices are superimposed on the start point S. In such a case, a side or a vertex is selected such that the current cut is inside the surface F1.

Next, a predetermined number of vertices are added to the face F1 in accordance with the position of the notch start point S on the side of the face F1 (substep 42).
Specifically, it is added to the surface F1 depending on whether the notch start point S coincides with a vertex on the side of the surface F1 or is at a place other than the vertex (hereinafter referred to as an intermediate point of the side). Determine the number of vertices. For example, as shown in FIG. 6B, when the notch start point S is at the middle point of the side L, three vertices (M21, M22, M23) are added to the face F1. On the other hand, when the start point S of the notch coincides with any of the existing vertices of the side L (for example, M2), this vertex M2 can be used even after the notch, so two vertices are added. . As a result, a linear cut having no area is generated inside the surface F1.

  Next, it is confirmed whether or not there is an imaginary line passing between the notch start point S and end point E (substep 43). If there is such a virtual line, the process proceeds to sub-step 44 to change the connection destination of the virtual line. If not, substep 31 is terminated. Note that the change of the connection destination of the virtual line in both the steps 43 and 44 is performed in common with the above-described four patterns of cutouts, and will be described in detail in the separation process described later.

<Sub-step 33: Cut-off process>
Next, the cut-off process will be described with reference to FIGS. FIG. 8 shows a specific example in which this cut-out process is performed. As shown in FIG. 8, in the “cutout”, the notch start point S is located inside the surface F1, and the end point E coincides with the side or vertex of the surface F1. Also in this case, similarly to the above-described cutting process, the surface F1 straddles the front and back of the surface F2, and the inside / outside determination regarding the graphic G2 of the surface F1 is unknown.

  As shown in the flowchart of FIG. 9, the sub-step 33 that performs the cut-out process includes sub-steps 51 to 54. First, in substep 51, the validity of the notch end point E is checked. Specifically, when the end point E is a cut-out end point created in the past, two sides or vertices are superimposed on the end point E. In such a case, a side or a vertex is selected such that the current cut-out is inside the surface F1.

Next, a predetermined number of vertices are added to the surface F1 in accordance with the position of the notch end point E on the side of the surface F1 (substep 52).
Specifically, the number of vertices to be added to the surface F1 is determined depending on whether the notch end point E coincides with the vertex on the side of the surface F1 or is at the middle point of the side. This vertex addition process is substantially the same as the sub-step 42 in the above-described cutting process. If the end point E is at the middle point of the side, three vertices are added, and if the end point E coincides with the side vertex, two vertices are added. Also in this case, a linear break having no area is generated inside the surface F1.

  Next, it is confirmed whether or not there is an imaginary line passing between the notch start point S and end point E (substep 53). If there is such a virtual line, the process proceeds to sub-step 54 to change the connection destination of the virtual line. If not, substep 33 is terminated. The change of the connection destination of the virtual line in both steps 53 and 54 will be described in detail in the separation process described later.

<Sub-step 35: cutting process>
Next, the cutting process will be described with reference to FIGS. 10 and 11. FIG. 10 shows a specific example in which this cutting process is performed. As shown in FIG. 10A, in the “cutting”, both the start point S and the end point E of the notch are located inside the surface F1. In this case as well, the face F1 straddles the front and back of the face F2, as in the above-described cutting process, and the inside / outside determination regarding the figure G2 on the face F1 is unknown. And the virtual line mentioned above is applied with respect to the surface F1 in which the cut was generated in this way.

  As shown in the flowchart of FIG. 11, the sub-step 35 that performs the cutting process includes sub-steps 61 to 64. First, in sub-step 61, the optimum positions as points connected by virtual lines are examined and selected for all the vertices constituting the surface F1 and the notch start point S and end point E. Next, the vertex of the selected surface F1 is connected to one of the notch start point S and end point E with a virtual line K (substep 62). An example of this case is shown in FIG. 10B.

  As shown in FIG. 10B, when the notch start point S and end point E are located inside the surface F1, the existing vertex M2 of the surface F1 and the notch start point S are represented by an imaginary line K. Connect with. Further, when this virtual line K is applied, five vertices (M21, M22, M23, M24, M25) are added to the surface F1.

  The imaginary line K is treated as a quasi-normal surface in the same manner as a normal surface even if it is an imperfect surface in which only a part of the inside of the imaginary line K has a linear cut. Making it possible. That is, by the virtual line K, a linear break generated in an independent state inside the surface F1 is connected to the existing vertex of the surface F1 and bridged to the side L of the surface F1. Thereby, this linear break can be expressed in a form that is taken into a set of vertices that express the data structure of the face F1. It should be noted that such an action by the virtual line K is similarly exerted on the “holed surface” described in step 01, and such “holed surface” can be handled as a quasi-normal surface.

  Next, it is confirmed whether or not there is an imaginary line passing between the notch start point S and end point E (substep 63). If there is such a virtual line, the process proceeds to sub-step 64 to change the connection destination of the virtual line. If not, substep 35 is terminated. The change of the connection destination of the virtual line in both steps 63 and 64 will also be described in detail in the separation process described later.

<Sub-step 37: cutting process>
Next, the separation process will be described with reference to FIGS. 12 and 13. FIG. 12 shows a specific example in which this segmentation process is performed. As shown in FIG. 12A, in the “cutting”, the start point S and the end point E of the notch are both coincident with the side or vertex of the surface F1. In this case, the surface F1 is divided by the surface F2, and it is determined whether the two pieces of the divided surface F1 are front or back with respect to the surface F2.

  As shown in the flowchart of FIG. 13, the sub-step 37 for performing the separation process includes sub-steps 71 to 79. First, in substep 71, the validity of the notch start point S and end point E is checked. Specifically, when the start point S and the end point E are on the start point, the end point, or an intermediate side of a notch created in the past, each of the points S and E has two sides or The vertices will overlap. In such a case, a side or a vertex is selected such that the separation by the start point S and the end point E is inside the surface F1.

  Next, it is checked whether or not both the start point S and the end point E of the notch coincide with the vertex of the surface F1 (substep 72). If they match, the process proceeds to substep 73, and if they do not match, the process proceeds to substep 75.

  Next, it is confirmed whether or not the notched section generated by the start point S and the end point E coincides with the virtual line applied to the face F1 (substep 73). If they match, the process proceeds to substep 74, and if they do not match, the process proceeds to substep 75. An example of this case will be described with reference to FIG.

As shown in FIG. 14A, the surface F1 is a perforated surface having holes P1, P2, P3, and P4 therein. In addition, virtual lines K1, K2, K3, and K4 are applied to the surface F1, and each of the holes P1 to P4 is connected to any vertex of the surface F1 or another hole by these virtual lines. .
Here, the section of the notch R1 newly generated in the portion between the hole P2 and the hole P3 coincides with the virtual line K3 connecting the hole P2 and the hole P3. In such a case, as shown in FIG. 14B, the existing virtual line K3 is converted into a normal side L1 (substep 74). After performing this conversion, the sub-step 37 is terminated.

  Next, it is confirmed whether or not the start point S and the end point E of the cutting are on different hole sides (substep 75). If it is on the side of a different hole, go to sub-step 76, otherwise go to sub-step 77.

For example, as shown in FIGS. 14A and 14B, the start point S and the end point E of the newly generated notch R2 are located on different sides of the holes P2 and P4, respectively. At this time, unnecessary virtual lines are deleted by the new notch R2.
Specifically, the hole P2 is connected to the vertex M2 of the surface F1 by the virtual line K2, and further connected to the hole P3 by the virtual line K3. Moreover, the hole P3 is connected with the hole P4 by the virtual line K4. At this time, the hierarchical relationship between the virtual lines K2 to K4 can be defined in the order of K2, K3, and K4 from the outer periphery of the face F1.

  In this case, the hole P2 and the hole P4 are connected by the newly generated side L2 due to the newly generated notch R2. Therefore, the virtual lines K4 that are lower than the virtual lines K2 and K4 corresponding to the holes P2 and P4, respectively, that are unnecessary due to the newly generated side L2, that is, the virtual lines K4 are deleted (substep 76). ). Further, the virtual line K2 at the higher level is preserved without being deleted.

  Another notch R3 occurs between the hole P1 and the outer periphery of the surface F1. Also in this case, the virtual line K1 is deleted with respect to the hole P1 as in the case described above.

Next, a predetermined number of vertices are added to each segment after division according to the positions of the notch start point S and end point E on the side of the face F1 (substep 77).
Specifically, the number of vertices added to each segment after division depending on whether the notch start point S and end point E coincide with the vertices on the side of the face F1 or are at the midpoint of the side. To decide. For example, as shown in FIG. 12B, when the notch start point S is located at the middle point of the side L of the surface F1 and the end point E coincides with the vertex M6 of the surface F1, the fragment F11 after division is performed. 2 vertices (M21, M22) are added to 1 and 1 vertex (M61) is added to the other divided fragment F12. When both the start point S and the end point E of the notch coincide with any one of the vertices of the face F1, one vertex is added to each of the divided fragments F11 and F12.

  As a result, it is determined whether the fragments F11 and F12 generated by the division are front or back with respect to the surface F2. Therefore, a flag indicating the front and back of the face F2 is added to each of the fragments F11 and F12. In this case, as shown in FIGS. 14A and 14B, a new notch R4 is generated at the upper portion of the surface F1, and is divided into different pieces above and below the notch R4. Each segment after the division is determined to have the front and back related to the surface F2, and a flag indicating that is attached.

  Even if the flag is added in this way, this flag may be changed in the case where the flag is further divided due to the notch of the next surface of the graphic G2 following the surface F2. In addition, when the notch formed on the next surface causes only the above-described line cut such as the notch to occur and no division occurs, the front and back flags once confirmed are canceled and again unconfirmed.

  Next, it is confirmed whether or not there is an imaginary line passing between the notch start point S and end point E (sub-step 78). If there is such a virtual line, the process proceeds to sub-step 79 to change the connection destination of the virtual line. If not, substep 37 is terminated.

  A specific example in this case is shown in FIG. As shown in FIG. 15A, in the plane F1, a new separation occurs inside, and the existing virtual line K passes between the start point S1 and the end point E1. In such a case, the connection destination of the virtual line K is changed to a virtual line K ′ that does not intersect the segmented section as shown in FIG. 15B (substep 79). After this change, substep 37 is terminated.

  Note that such a change in the connection destination of the virtual line is performed in the same manner in the above-described cutting, cut-out, and cutting processes. That is, the virtual line K passing between the start point S2 and the end point E2 of the new cut shown in FIG. 15A, the start point S3 and the end point E3 of the cut-out, and the start point S4 and the end point E4 of the cut-in is shown. In some cases, as shown in FIG. 15B, the connection destination of the virtual line K is changed to a virtual line K ′ that does not intersect with each section.

  Next, returning to FIG. 4 again, the processing after sub-step 14 will be described. First, for all the faces of the graphic G2, it is confirmed whether or not the cut processing of the face F1 and all the fragments generated from it has been completed (sub-step 14). If not finished for all the faces, the next face is taken out from G2 and is designated as face F2 (sub-step 15), the process returns to sub-step 13, and sub-steps 13 and 14 are repeated until all faces are finished. . If completed, go to substep 16.

  Subsequently, it is confirmed whether or not the notch processing by G2 is completed for all the faces of the figure G1 (substep 16). If all the faces have not been completed, the next face is taken out from G1 and is designated as face F1 (substep 17), the process returns to substep 12, and substeps 12 to 16 are repeated until all the faces are finished. . If completed, end step 02.

  As described above, the process of cutting the figure G1 by the figure G2 is reduced to the repetition of the notch process of the face F1 by the face F2 and all fragments generated therefrom. That is, the analysis of the interpenetration relationship in the graphics G1 and G2 is reduced to the analysis of the interpenetration relationship between the surfaces constituting each graphic.

  If the front and back of the surface F1 with respect to the graphic G2 are not determined as a result of performing the notch processing for all the surfaces of the graphic G2 on the surface F1, supplementary processing is performed to determine the front and back. May be. For example, if all the faces of the figure G2 are on the same side (above or below the face F1) with respect to the face F1, the face F1 is determined to be on the table (outside) of the figure G2, and the face F1 If all the faces of G2 are on the lower side, the face F1 may be determined to be behind (inside) the figure G2.

<Step 03: Removal of the back side portion>
Returning to FIG. 2 again, the processing after step 02 will be described. In step 03, the control means 2 removes the part on the back side of the graphic G2 in the graphic G1.
This removal is performed based on the flag indicating the front and back attached to each piece of the surface F1 in the sub-step 77 described above. That is, on all the surfaces constituting the graphic G1, the fragments with the flag indicating the back are collectively removed. As a result, in the graphic G1, when it is combined with the graphic G2, a portion that is not displayed on the back side of the graphic G2 is removed.

<Step 04: Composite Display of Figures G1 and G2>
Next, in step 03, the control means 2 synthesizes the figure G1 composed of the surface having the portion that has not been removed and the figure G2, and displays the result on the display means 7 such as a display. Present to the user.

  An example of this display is shown in FIG. Here, an example is shown in which a composite screen of the terrain X as the graphic G1 and the structure Y as the graphic G2 is displayed. In this example, the composite screen of the terrain X and the structure Y is displayed with high accuracy, and in particular, only necessary and sufficient line segments are not generated at the junction between the terrain X and the slope y1. Is displayed.

  Even if the displayed figures G1 and G2 include a surface to which the above-described virtual line is applied, a texture display for displaying the texture of the surface of the figure and a contrast of light and dark are displayed. In the case of shading display, it can be displayed in the same manner as a normal figure that does not include virtual lines.

  Further, when the figures G1 and G2 include virtual lines as described above, the virtual lines may be set to be non-displayed and not displayed on the display unit 7. For example, when a graphic including a virtual line is displayed in a wire frame (line shape), a display screen with less noise can be obtained by hiding the virtual line. Thereby, the shape of the figure after figure calculation can be displayed in an easy-to-understand manner as compared with the conventional triangulation.

  As described above, according to the three-dimensional figure calculation program of the present invention, the process of cutting the figure G1 by the figure G2 can be reduced to the repetition of the notch process of the face F1 by the face F2. As a result, complicated three-dimensional graphic operations can be simplified, and highly accurate graphic operations can be performed while suppressing an increase in the amount of data.

  In addition, by applying virtual lines, surfaces with holes in the surface, or surfaces that are incomplete, such as when there is a line break in only a part of the surface notch processing Can be handled as a quasi-normal surface. As a result, these imperfect surfaces can be expressed without dividing the figure as in the prior art, and the cut-out process between the surfaces can be performed in the same manner as a normal surface.

Further, in this way, by handling the quasi-normal surface in the surface notch processing, a special data structure such as a buffer and a stack becomes unnecessary. This simplifies the process and suppresses an increase in the amount of data.
Further, when a new notch is generated on the quasi-normal surface, the virtual line is deleted or the connection destination is changed according to the new notch occurrence state. As a result, the virtual line is always appropriately applied to the quasi-normal surface, and the processing can be accurately performed even in the continuous notch processing.

  In addition, when an error occurs in the notch processing of the surface F1 by the surface F2 and all the fragments generated thereafter in the sub-step 13, the two surfaces or the combination of the surfaces and the fragments that are in error are used as an error log. Alternatively, it may be recorded in the recording means 5 such as a hard disk drive device.

  That is, in most cases, the graphic calculation error occurs in the process of notching the surface F1 by the surface F2 and all the fragments generated therefrom. At this time, by recording the data of the face F1 or the fragment in which the error has occurred and the data of the face F2 as an error log, the location of the face in which the error has occurred after the completion of the figure calculation is processed. Can be easily searched from. Also, if the error that has occurred is due to the incompleteness of the 3D graphics operation program, this error log can be used to modify and test the program, which makes the program more maintainable. Can be improved.

  The three-dimensional graphic operation program of the present invention can also be provided as a dynamic link library (DLL) that is loaded onto a memory and executed. In this way, by providing the 3D graphics operation program of the present invention as a dynamic link library, it is possible to make corrections and updates independently without affecting other programs, and this also improves maintainability. To do.

  Further, by making the three-dimensional graphic operation program independent as a dynamic link library in this way, the three-dimensional graphic operation function realized by this three-dimensional graphic operation program can be provided as an independent function. Thereby, the application range of such a three-dimensional figure calculation function is not limited to the one for the purpose of studying the landscape, such as the landscape examination device according to the present embodiment, and is also applied to various other devices. be able to. In this case, the dynamic link library may be provided to each computer on the network via an in-house network or the Internet.

1 Landscape examination device 2 Control means (CPU)
3 Storage means (RAM)
4 Storage means (ROM)
5 recording means 6 input means 7 display means 8 communication interface 9 imaging means 10 holed surface 11 hole 12 vertex K virtual line S notch start point E notch end point

Claims (10)

A three-dimensional graphic calculation program that analyzes the interplay relationship of a plurality of three-dimensional figures in a three-dimensional space, removes overlapping parts from each other, and synthesizes and displays each three-dimensional figure.
A first step of expressing each three-dimensional figure into a shape approximating a polyhedron that is a set of faces;
In each three-dimensional figure expressed in the shape approximated to the polyhedron in the first step, the interplay relation of all the faces constituting the other three-dimensional figure with respect to all the faces constituting the one three-dimensional figure is analyzed. A second step to
Based on the analysis result of the interpenetration relationship between the surfaces in the second step, in each surface constituting one three-dimensional graphic, a third step of removing a portion that overlaps with another three-dimensional graphic and becomes the back side;
A fourth step of synthesizing and displaying three-dimensional figures composed of surfaces having portions not removed in the third step , and
The analysis of the interpenetration relationship between the surfaces in the second step is performed based on the notch state between each surface constituting one three-dimensional figure and each surface constituting another three-dimensional figure. An incision step that performs processing when the notch starts at the edge or vertex of the other face and ends inside the other face;
A cut-out step for performing processing when a notch by one surface starts from the inside of the other surface and ends at the edge or vertex of the other surface;
A cutting step for performing processing when a notch by one surface starts from the inside of the other surface and ends inside the other surface;
A cutting step for determining the front and back of the divided surface of each of the plurality of fragments after the division when the other surface is divided into a plurality of fragments by the notch of one surface,
A three-dimensional graphic operation program for causing a computer to execute the above steps . Among the surfaces of the three-dimensional figure expressed in the shape approximated to the polyhedron in the first step, for the surface having a hole inside the surface, any vertex constituting the hole and the surface having the hole are configured. claim 1 three-dimensional figure computation program, wherein further comprising a sub-step of the vertices connected by imaginary line. In the cutting step, with respect to the surface having a linear cut having no area inside the surface, a sub-step of connecting one end of the cut and any vertex constituting the surface having the cut with a virtual line three-dimensional figure computation program according to claim 1 or 2, characterized in that it further comprises a. When a new notch due to another surface occurs in the second step for the surface having the virtual line, the virtual line is deleted or the connection destination is changed according to the occurrence of the new notch. The three-dimensional figure calculation program according to claim 2 or 3 , further comprising a sub-step. The three-dimensional figure calculation program according to any one of claims 2 to 4 , wherein the virtual line can be set to non-display during the composite display in the fourth step. It is determined whether each surface of the three-dimensional figure expressed in a shape approximated to a polyhedron in the first step is normal or abnormal as a target to which the processing after the second step is applied. The three-dimensional figure calculation program according to any one of claims 1 to 5 , further comprising a sub-step of correcting the curved surface. Any second result of the analysis phase transmural relationship faces thereof in step, we claim 1, characterized in that it further comprises a sub-step of recording in the recording means the combination of the surface became analytical error as the error log 6 A three-dimensional graphic operation program described in the above. A dynamic link library to be executed by loading into memory, dynamic link libraries, characterized in that it includes a three-dimensional graphic calculation program according to any one of claims 1 to 7. A landscape examination device that analyzes 3D data of terrain or a structure, displays a composite screen of the terrain or structure in a 3D space, and simulates and examines the landscape,
Input means for inputting the three-dimensional data of the topography or structure;
Recording means for recording the inputted three-dimensional data;
Storage means for storing the three-dimensional graphic operation program according to any one of claims 1 to 7 ,
Control means for executing the three-dimensional graphic calculation program stored in the storage means and generating the composite screen based on the three-dimensional data of the topography or structure;
Display means for displaying the generated composite screen;
A landscape examination device characterized by comprising: Imaging means for acquiring imaging data of the terrain or structure;
The landscape examination apparatus according to claim 9 , further comprising a communication interface for receiving imaging data acquired by the imaging means.