JP2004094750A - Three-dimensional configuration processor, interference model detecting method, program and storage medium - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an interference model detecting method for detecting an interference model during the movement of a partial model. <P>SOLUTION: When the partial model of an assembled model expressed by a polygon mesh moves in a three-dimensional space, this three-dimensional configuration processor detects the condition of interference between the moving partial model and another partial model than the partial model. Boundary box information is found about each of the partial models of the assembled model subject to interference detection, a face as part of the partial model and a polygon as part of the face. There are provided a boundary box information generation updating part 14 for updating the boundary box information about the partial model, the face as part of the partial model and the polygon as part of the face in response to the movement of the partial model during the movement of the partial model and interference determining parts 15, 16, 17 using the updated boundary box information for detecting the interference between the partial models with rough check of the partial model, the face and the polygon in sequence. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a three-dimensional interference model detection method which can be used for shape evaluation in a CAD (Computer Added Design) / CAM (Computer Added Manufacturing) system.
[0002]
[Prior art]
In recent years, with the spread of 3D CAD / CAM / CG systems, etc., the number of users of 3D shape data has expanded, and simulations for detecting interference (overlapping and collision) of partial models such as subassemblies and parts, and verification of assemblability. There are increasing opportunities to effectively utilize three-dimensional shape data in various situations. It is becoming commonplace to analyze / verify three-dimensional shape data generated by a CAD system or the like on a computer before moving to a manufacturing process. In particular, for an assembly model composed of a plurality of partial models (corresponding to subassemblies and parts), a function of detecting interference between the individual partial models checks a design error or an input error in a CAD / CAM system. This function is useful for shape evaluation.
By the way, in many cases, data used to represent a shape in three-dimensional shape display is data obtained by approximating a free-form surface with a polygon mesh. Therefore, when detecting the interference state of a plurality of partial models each represented by a polygon mesh, an interference calculation between polygons is finally performed to determine whether the partial models are interfering with each other. There is a need to.
However, if a brute force interference check is performed between polygons constituting individual partial models, an enormous processing time is required for a large-scale assembly, and interactive operability is significantly impaired.
For this reason, in the prior art disclosed in Japanese Patent Application Laid-Open No. 9-27046, in the case of interference check between polyhedrons including non-convex portions, first, a convex portion is detected, interference check is performed on the convex portion, and interference is detected. Only when there is, the interference check between adjacent polygons is performed.
In the prior art disclosed in Japanese Patent Application Laid-Open No. 9-179896, an inspection point for inspecting the presence or absence of interference is defined, and a solid angle at the inspection point is used to determine whether the inspection point is included in the other figure. The presence or absence of interference is inspected by determining whether or not there is interference.
[0003]
[Problems to be solved by the invention]
However, in the prior art disclosed in the above-mentioned Japanese Patent Application Laid-Open No. 9-27046, since a process for detecting a convex portion is required, calculation becomes complicated in a complicated shape such as a subassembly. Further, the prior art disclosed in Japanese Patent Application Laid-Open No. 9-179896 is effective only when defining an inspection point.
Therefore, in the invention recently filed by the present applicant, before performing costly interference detection between polygons, a bounding box which is a rectangular parallelepiped region expressing a minimum outline in a three-dimensional space including a partial model is used. Perform a rough check. In such a method, a state in which no interference occurs can be excluded early, so that the overall processing speed can be improved. The bounding box refers to a rectangular parallelepiped that has surfaces parallel to the XY plane, YZ plane, and ZX plane in the three-dimensional space where the geometric information is defined, and circumscribes the target three-dimensional shape. It is represented by a total of six values including the minimum value and the maximum value of (X, Y, Z). Further, as for the interference state between the bounding boxes, it is possible to use a determination method that the interference does not occur if any one of the minimum values exceeds the other maximum value in any one of the X, Y, and Z directions. A rough check (detection of a state where there is no possibility of interference) can be performed with a small calculation cost.
In another invention recently filed by the present applicant, in the above, the partial box and the bounding box information of the surface are held in a bounding box table with values based on one coordinate system, and the By reducing the number of times of coordinate transformation, the processing time required for the interference check can be reduced.
The present invention further provides, in the above, an interference model detection method capable of detecting an interference model during an interactive operation of moving a partial model.
[0004]
[Means for Solving the Problems]
In order to solve the above problem, according to the first aspect of the present invention, when an arbitrary partial model in a three-dimensional assembly model represented by a polygon mesh is moved in a three-dimensional space, the moved part In a three-dimensional shape processing apparatus capable of detecting an interference state between a model and all of the partial models other than the partial model, each partial model of a three-dimensional shape assembly model to be subjected to interference detection, and the partial model Bounding box information calculating means for obtaining bounding box information for the surface forming the surface and the polygons constituting the surface, and, when the partial model is moved, the partial model corresponding to the movement of the partial model; Bounding box information updating means for updating the bounding box information for the faces constituting the partial model and the polygons constituting the faces, and an updated bounding box Using broadcast, partial model, surface, characterized in that a interference detection means for detecting an interference between partial model by performing rough check in the order of the polygon.
According to the second aspect of the present invention, when an arbitrary partial model in a three-dimensional shape assembly model represented by a polygon mesh is moved in a three-dimensional space, the moved partial model and other than the partial model In the interference model detection method for detecting an interference state between all of the partial models, a partial model of a three-dimensional shape assembly model to be detected, a surface forming the partial model, and a surface forming the surface Boundary box information is obtained for the polygons that have been moved, and when moving the partial model, the partial model, the planes constituting the partial model, and the planes corresponding to the movement of the partial model are configured. Update the bounding box information for the existing polygons and use the updated bounding box information to perform a rough check in the order of partial model, face, and polygon Characterized in that the structure for detecting the interference between partial model Ri.
[0005]
According to a third aspect of the present invention, in the second aspect of the invention, when the moving partial model is a sub-assembly, the bounding box information is updated for all the partial models included in the sub-assembly. And
According to a fourth aspect of the present invention, in the second or third aspect, the bounding box information of the partial model, the face, and the polygon is based on a common coordinate system in the three-dimensional shape assembly model. It is characterized in that it is configured to hold the value.
According to a fifth aspect of the present invention, in the fourth aspect of the present invention, when obtaining the bounding box information of the partial model, the vertex coordinate values included in all the polygons constituting each surface of the partial model Is converted into vertex coordinate values based on the common coordinate system, and the maximum and minimum values of the components in the X, Y, and Z axis directions on the three-dimensional space are detected from the converted vertex coordinate values. It is characterized in that bounding box information is obtained.
According to a sixth aspect of the present invention, in the invention of the fifth aspect, when obtaining the bounding box information of the surface, the vertex coordinate values included in the polygons constituting the surface are converted into the common coordinate system. Is converted to vertex coordinate values based on the reference, and the maximum value and the minimum value of the components in the X, Y, and Z axis directions on the three-dimensional space are detected from the converted vertex coordinate values to obtain the bounding box information. It is characterized by having done.
According to a seventh aspect of the present invention, in the program executed on the information processing apparatus, the interference model detection by the interference model detection method according to any one of the second to sixth aspects is performed. It is characterized by having been programmed to.
The invention according to claim 8 is characterized in that the program according to claim 7 is stored in a storage medium storing the program.
[0006]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a hardware configuration diagram of a three-dimensional shape processing apparatus according to the present invention. As shown, the three-dimensional shape processing apparatus includes a CPU 1 that operates according to a program, a memory (eg, a RAM) 2 that temporarily stores the program and various data, and an external storage device that stores the program and various data. (For example, a hard disk device) 3, a reading device for reading data from a removable storage medium, an input device 4 having a keyboard, a mouse, etc. for inputting various data and instructions including three-dimensional shape data, a three-dimensional shape model, and the like. A display device 5 and the like for displaying are provided.
FIG. 2 is a system configuration diagram of a three-dimensional shape processing system according to an embodiment of the present invention, which is realized by the above-described hardware and the program (software). As shown in the figure, the three-dimensional shape processing system of this embodiment includes an input unit 11 for inputting various data and instructions including three-dimensional shape data from an input device 4, and acquires the input three-dimensional shape data to store the shape. The input reading unit 12 stored in the unit, the shape storage unit 13 which is a memory area for temporarily storing three-dimensional shape data, etc., the respective partial models of the three-dimensional shape assembly model to be subjected to interference detection, and the respective partial models are configured. Surface information and the bounding box information of the polygons that make up each of the surfaces, and when moving the partial model, configure the partial model and the partial model corresponding to the movement of the partial model. Box information generating / updating unit 14 that updates bounding box information for a plane that is present and the polygons that make up that plane, and that the interference between the partial models is obtained using the bounding box information. A model boundary interference determination unit 15 that determines whether or not there is interference by performing a check, similarly a surface boundary interference determination unit 16 that performs a surface interference check to determine whether or not there is interference, and similarly performs an interference check between polygons A polygon boundary interference determination unit 17 that determines the presence or absence of interference, and a shape display unit 18 that generates display data and causes the display device 5 to display a three-dimensional shape model or the like. In this embodiment, the bounding box information calculating means and the bounding box information updating means are realized by the bounding box information generating / updating unit 14, and the interference detecting means is a model boundary interference determining unit 15, a surface boundary This is realized by the interference determination unit 16 and the polygon boundary interference determination unit 17. Further, the partial model (hereinafter, simply referred to as a model) is a representation of subassemblies and parts constituting a three-dimensional shape assembly by three-dimensional shape data.
[0007]
FIG. 3 shows an operation flow of interference model detection performed by the three-dimensional shape processing system as described above. Hereinafter, this operation flow will be described with reference to FIG.
First, for each model constituting the assembly model, each face constituting each model (Face), and each polygon constituting each surface, bounding box information is generated in each unit, and the model ID (identifier) and the face The bounding box information that can be referred to by the ID and the polygon ID is stored in the model bounding box information table, the face bounding box information table, and the polygon bounding box information table, respectively (S1).
At this time, the bounding box information of the model or the surface may be generated as a rectangular parallelepiped region including all the vertex coordinate values of the polygon mesh constituting the model or the surface, or may be generated from an external system such as a CAD system. If the model and the bounding box information of the surface can be acquired for the shape data, it may be used. For example, when generating the bounding box information of the model from the vertex coordinate values of the polygon mesh, the minimum values (X-min, Y-min, Z-min) for each (X, Y, Z) of the vertex coordinate values, Bounding box information can be obtained by finding the maximum values (X-max, Y-max, Z-max). When generating the bounding box information from the vertex coordinate values of the polygon mesh, if the vertex coordinate values are not based on one coordinate system, for example, the vertex coordinate values are based on a local coordinate system for each model in the assembly model. If the value is to be converted into a value based on the top assembly model, which is the highest level of the assembly model, and converted to the common coordinate system reference value, the maximum value and the minimum value for each component are calculated. Search and store. Similarly, when the model or surface bounding box information obtained from an external system such as a CAD system is not based on one coordinate system in the assembly model, the bounding box information is similarly calculated from the vertex coordinate values of the polygon mesh. Generate
[0008]
Next, for the moving model, the bounding box information in the model bounding box information table, face bounding box information table, and polygon bounding box information table generated in step S1 is recalculated (S2). Since the moving model is indicated by a mouse or the like, it is recognized and used as the moving model. Also, the vertices of the polygon mesh for the moving model are automatically updated according to, for example, the current position of the model. The coordinates of each vertex are relatively changed according to the amount of change in the coordinates detected by the mouse. Or, keep the vertices of each polygon mesh in the initial state (the state before performing any model movement), and also hold the model movement information (eg, transformation matrix) and update the movement information You may make it.
Subsequently, a rough check for investigating an interference state (overlap / collision state) is performed using the updated bounding box information. The following rough check is performed by appropriately referring to the model bounding box information table, the surface bounding box information table, and the polygon bounding box information table.
First, of all the combinations of the moving model (if the moving model is a sub-assembly, each model in the sub-assembly) and each model on the stationary side, the bounding box of the model It is checked whether interference occurs (S3). The model bounding box information is referred to from the model bounding box information table updated in step S2, and if the minimum value of any one of the bounding boxes exceeds the maximum value of the other bounding box in any of the X, Y, and Z directions. It is determined that there is no interference. If it is determined that the bounding box of the model of the combination does not interfere (NO in S4), the process proceeds to the next model combination (S3).
[0009]
On the other hand, if it is determined that the bounding boxes of the models are interfering (YES in S4), it is considered that the two models may have interference, and all of the two models are extracted one by one from each. It is checked whether the bounding box of the surface interferes with one of the combinations (S5). At this time, the surface bounding box information is referred to from the surface bounding box information table updated in step S2. When it is determined that the two bounding boxes do not interfere with each other (NO in S6), the process proceeds to the next combination of faces (S5).
On the other hand, if it is determined that the two bounding boxes interfere (YES in S6), it is considered that the two surfaces may possibly interfere with each other, and one polygon is extracted from each of the two surfaces. It is checked whether or not one of all the combinations interferes with the bounding box of the polygon (S7). At this time, the polygon bounding box information is referenced from the polygon bounding box information table updated in step S2. If it is determined that the bounding boxes of the two polygons do not interfere with each other (NO in S8), the process proceeds to the next polygon combination (S7).
On the other hand, if it is determined that the bounding box of the two polygons interferes (YES in S8), it is considered that the two polygons may interfere, and whether or not the two polygons themselves are in an interference state is determined. Check (S9). Note that a generally known geometric analysis method may be used as a method for checking interference between polygons. For example, an interference calculation is performed between a line segment connecting vertices constituting one polygon and a plane on which the other polygon rides, and it is determined whether or not the obtained intersection exists in the polygon. If it is determined that the polygons are interfering with each other, a result is obtained that the two models interfere with each other at the positions of the two polygons on the two surfaces.
[0010]
When the interference detection processing is completed for one combination of polygons, it is determined whether or not the interference check has been completed for all combinations of polygons (S10), and if not completed (NO in S10), the process proceeds to the next combination of polygons. The process is shifted (S7). When the interference check is completed for all the combinations of the polygons of the two surfaces (YES in S10), it is determined whether the interference check is completed for all the combinations of the surfaces of the two models (S11). (NO in S11) The process proceeds to the next combination of surfaces (S5).
In this way, when the interference check is completed for all the combinations of the surfaces of the two models (YES in S11), it is determined whether the interference check is completed for all the combinations of the models described above (S12), and if not completed (S12). NO), the process is shifted to the next model combination (S3). When the interference check is completed for all the combinations of the models (YES in S12), it is determined whether or not there is a moving model at that time (S13). If there is, the model is repeated from the update of the bounding box information (S2). If there is no moving model (NO in S13), the operation flow ends.
In the above, one embodiment of the present invention has been described in the case of the system configuration shown in FIG. 2, but a program programmed according to the interference model detection method as described above is stored in a removable storage medium, and the storage medium is By mounting the information processing apparatus such as a personal computer that could not perform the interference model detection according to the present invention, or by transferring such a program to such an information processing apparatus via a network, the information is obtained. The interference model detection according to the present invention can also be performed in the processing device.
[0011]
【The invention's effect】
As described above, according to the present invention, according to the first and second aspects of the present invention, the respective partial models of the three-dimensional shape assembly model to be detected by the polygon mesh, and the partial models are configured. Bounding box information is obtained for the surface and the polygons constituting the surface, and when an arbitrary partial model in the three-dimensional assembly model is moved in the three-dimensional space, the moved part When detecting the state of interference between the model and all the partial models other than the partial model, the partial model, the planes constituting the partial model, and the planes corresponding to the movement of the partial model are detected. The bounding box information is updated for the polygons that make up the polygon, and a rough check is performed in the order of the partial model, face, and polygon using the updated bounding box information. Since interference between minute models is detected, even in the case of interference model detection during an interactive operation of moving a partial model, it is possible to reduce the number of coordinate transformations in the interference check process, thereby reducing interference. The processing time required for the check can be reduced. Further, since only the information necessary for the interference check when moving the partial model is updated among the partial box information of the partial model, the surface, and the polygon generated for the rough check, the speed of the interference check is increased.
Further, in the invention according to claim 3, in the invention according to claim 2, when the partial model to be moved is a subassembly, the bounding box information is updated for all the partial models included in the subassembly. Even in the case of a subassembly, the effect of the invention described in claim 1 can be obtained.
According to a fourth aspect of the present invention, in the second or third aspect, the bounding box information of the partial model, the face, and the polygon is based on a common coordinate system in the three-dimensional assembly model. Since the value is held as a value, the number of coordinate conversions in the interference check processing is reduced, and the interference check can be performed at a high speed.
[0012]
According to a fifth aspect of the present invention, in the fourth aspect of the present invention, when obtaining the bounding box information of the partial model, the vertex coordinate values included in all the polygons constituting each surface of the partial model Are converted into vertex coordinate values based on a common coordinate system, and the maximum and minimum values of the components in the X, Y, and Z-axis directions on the three-dimensional space are detected from the converted vertex coordinate values. Since the value and the minimum value are used as the bounding box information, it is possible to prevent an increase in processing time for obtaining the bounding box information of the partial model even if the shape data of each partial model is held in a local coordinate system.
According to a sixth aspect of the present invention, in the invention of the fifth aspect, when obtaining the bounding box information of a surface, the vertex coordinate values included in the polygons constituting the surface are based on a common coordinate system. The maximum value and the minimum value of the components in the X, Y, and Z axis directions in the three-dimensional space are detected from the converted vertex coordinate values, and the maximum value and the minimum value are determined by a bounding box. Since the information is information, even if the shape data of each partial model is held in a local coordinate system, it is possible to prevent an increase in processing time for obtaining the surface box information.
According to a seventh aspect of the present invention, a program programmed to execute the interference model detection by the interference model detection method according to any one of the second to sixth aspects is stored on an information processing apparatus. Since the present invention can be executed, the effect of the invention described in any one of claims 2 to 6 can be obtained using an information processing device.
In the invention according to claim 8, the program according to claim 7 can be stored in a removable storage medium, so that the storage medium has been described in any one of claims 2 to 6. By mounting the present invention on an information processing device such as a personal computer that cannot detect the interference model according to the invention, the effect of the invention described in any one of claims 2 to 6 is obtained in the information processing device. be able to.
[Brief description of the drawings]
FIG. 1 is a hardware configuration diagram of a three-dimensional shape processing apparatus in which the present invention is implemented.
FIG. 2 is a system configuration diagram of a three-dimensional shape processing system according to an embodiment of the present invention.
FIG. 3 is an operation flowchart of an interference model detection method according to an embodiment of the present invention.
[Explanation of symbols]
1 CPU, 2 memories, 3 external storage devices, 4 input devices, 5 display devices, 11 input units, 13 shape storage units, 14 bounding box information generation / update units, 15 model boundary interference determination units, 16 plane boundary interference determination units, 17 polygon boundary interference judgment unit, 18 shape display unit

Claims (8)

When an arbitrary partial model in a three-dimensional assembly model represented by a polygon mesh is moved in a three-dimensional space, interference between the moved partial model and all the partial models other than the partial model In a three-dimensional shape processing device capable of detecting a state,
Bounding box information calculating means for obtaining bounding box information for each of the partial models of the three-dimensional shape assembly model to be subjected to interference detection, the faces constituting the partial models, and the polygons constituting the faces; Boundary box information updating means for updating bounding box information for the partial model, the planes constituting the partial model, and the polygons constituting the plane in response to the movement of the partial model during the movement And three-dimensional interference detection means for performing a rough check in the order of the partial model, the surface, and the polygon using the updated bounding box information to detect interference between the partial models. Shape processing equipment. When an arbitrary partial model in a three-dimensional shape assembly model represented by a polygon mesh is moved in a three-dimensional space, interference between the moved partial model and all the partial models other than the partial model In an interference model detection method for detecting a state,
Boundary box information is obtained for each partial model of the three-dimensional shape assembly model to be subjected to interference detection, the planes constituting the partial model, and the polygons constituting the plane. Corresponding to the movement of the partial model, the bounding box information is updated for the partial model, the planes constituting the partial model, and the polygons constituting the plane, and using the updated bounding box information, An interference model detection method characterized by detecting interference between partial models by performing a rough check in the order of a partial model, a surface, and a polygon. 3. The interference model detection method according to claim 2, wherein when the moving partial model is a sub-assembly, the bounding box information is updated for all the partial models included in the sub-assembly. The interference model detection method according to claim 2 or 3, wherein the bounding box information of the partial model, the face, and the polygon is held as a value based on a common coordinate system in the three-dimensional shape assembly model. Interference model detection method. 5. The method for detecting an interference model according to claim 4, wherein when obtaining the bounding box information of the partial model, the vertex coordinate values included in all the polygons constituting each surface of the partial model are converted into the common coordinate system. Is converted into vertex coordinate values based on, and maximum and minimum values of components in the X, Y, and Z axis directions in a three-dimensional space are detected from the converted vertex coordinate values to obtain bounding box information. A featured interference model detection method. 6. The method for detecting an interference model according to claim 5, wherein when obtaining the bounding box information of the surface, the vertex coordinate values included in the polygons constituting the surface are determined by the vertex coordinate values based on the common coordinate system. A method for detecting bounding box information by detecting maximum and minimum values of components in the X, Y, and Z axes in a three-dimensional space from the converted vertex coordinate values. . A program executed on the information processing apparatus is programmed to execute interference model detection by the interference model detection method according to any one of claims 2 to 6. program. A storage medium storing the program according to claim 7, wherein the storage medium stores the program.

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