KR20110133363A - Collision detection method of polygon model using obbtree and subdivision - Google Patents

Abstract

PURPOSE: A collision detection method of polygon model using OBB(Oriented Bounding Box) tree and a mesh division method is provided to perform collision test by applying the mesh division method and the OBB tree to a polygon model. CONSTITUTION: A mesh division method is applied to a polygon model(201) of a machine parts. Mesh information is added(202). The mesh information is the lattice information of the polygon model. The machine parts have a simple shape. An OBB tree is created by using the added mesh information(203). A collision test is performed by using the created OBB tree(204).

Description

Collision detection method of polygon model using OBBTree and subdivision}

The present invention relates to a collision detection method of a polygon model using a dichotomous bounding box tree and a mesh segmentation technique, and a computer-readable recording medium recording a program for realizing the method. In the collision inspection, collision of polygon model using the dichotomous boundary box tree and mesh dividing technique, which can generate reliable collision inspection results by applying the mesh segmentation technique and the dichotomous boundary tree to the polygon model, is performed. A test method and a computer-readable recording medium having recorded thereon a program for realizing the method.

First, in order to help the understanding of the present invention, look at the important terms used in the present invention are summarized as follows.

First, polygons are polygons of the smallest unit used to express three-dimensional shapes in three-dimensional computer graphics.

The mesh information refers to geometric information, that is, grid information of the polygon model.

Oriented bounding box (OBB) refers to a bounding box based on a certain axis that contains the real model for fast collision detection on the polygon model. The dicing box is used to perform collision inspection instead of the polygon model.

The OBBT refers to a directional box group generated by separating the directional box using geometric information (ie, grid information of the polygon model). In other words, the diversion boundary box is separated by using geometric information, that is, the grid information of the polygon model, to generate the diversion boundary box tree. The collision detection can be performed using the generated omnidirectional boundary tree.

On the other hand, in the following embodiment of the present invention will be described by taking a machine part polygon model as an example, the present invention can be variously applied, such as collision inspection of other part polygon model, it will be found that not limited to the machine part polygon model in advance Put it.

According to the conventional collision checking method between models, a collision box including a seal model is generated in a seal model, and then collision checking is performed between the generated bound boxes. The type of bounding box includes, for example, BS (Bounding Sphere), AABB (Axis Aligned Bounding Box), OBB (Oriented Bounding Box), DDS (Discrete Bounding Box, k-dop), and the like. .

The reason for generating a bounding box as described above is to quickly perform a collision check like a real polygon model by performing a collision check between the generated bounding boxes after generating a bounding box as close to the actual model as possible.

By the way, in the prior art as described above, when attempting to generate a directed boundary box tree for collision inspection in a mechanical component having a relatively simple shape, the directed boundary box tree is generated close to the actual model, but the mesh information (geometric information, In other words, the grid information of the polygon model is small, and even though the directional boundary tree close to the actual model is not generated or the directional boundary tree is generated, it is usually larger than the actual model.

When collision inspection is performed by using the directional box tree that is separated from the actual model generated in this way, a lot of errors occur in the collision inspection, which lowers the reliability of the collision inspection result.

As described above, the prior art as described above has a problem of low reliability of the collision inspection result, and it is an object of the present invention to solve this problem.

Therefore, in the present invention, when the collision inspection of the machine part polygon model, etc., the collision detection is performed by applying the mesh segmentation technique and the dichotomous boundary tree to the polygon model, so that a reliable collision inspection result can be derived. And a collision detection method of a polygon model using a mesh division technique, and a computer-readable recording medium recording a program for realizing the method.

That is, according to the present invention, when generating a directed boundary box tree from a concave or less geometrical polygon model, it is not generated too largely or smoothly than the shape of the actual model. By creating a Boundary Boundary box tree similar to the actual model shape, and performing a collision test using a Boundary Boundary box tree that has a shape close to the real model generated in this way, it can derive reliable collision inspection results. An object of the present invention is to provide a collision detection method for a polygon model using a tree and mesh division technique and a computer-readable recording medium recording a program for realizing the method.

The objects of the present invention are not limited to the above-mentioned objects, and other objects and advantages of the present invention which are not mentioned can be understood by the following description, and will be more clearly understood by the embodiments of the present invention. Also, it will be readily appreciated that the objects and advantages of the present invention may be realized by the means and combinations thereof indicated in the claims.

According to an aspect of the present invention, there is provided a collision inspection method in a collision inspection system, comprising: adding mesh information by applying a mesh division technique to a polygon model; Generating a dichotomous bounding box tree by using the added mesh information; And a collision inspection step of performing collision inspection using the generated omnidirectional boundary box tree.

On the other hand, the present invention, a mesh information adding step of adding mesh information to the collision detection system having a processor by applying a mesh segmentation technique to the polygon model; Generating a dichotomous bounding box tree by using the added mesh information; And a computer-readable recording medium having recorded thereon a program for realizing a collision inspection performing step of performing collision inspection using the generated omnidirectional boundary box tree.

In the present invention as described above, when the collision inspection of the machine part polygon model, etc., the collision inspection is performed by applying the mesh splitting technique and the dichotomous boundary tree to the polygon model, thereby obtaining a reliable collision inspection result. have.

That is, according to the present invention, when generating a directed boundary box tree from a concave or less geometrical polygon model, it is not generated too largely or smoothly than the shape of the actual model. By creating a Boundary Boundary box tree similar to the actual model shape, the collision inspection is performed by using a Boundary Boundary box tree that has a shape close to the actual model. have.

1A and 1B are diagrams illustrating an embodiment of a collision inspection system of a polygon model to which the present invention is applied;
2 is a flowchart illustrating a collision detection method of a polygon model using a dichotomous boundary box tree and a mesh segmentation method according to the present invention;
3 is a view for explaining the principle of mesh division;
4 is a diagram illustrating a mesh division execution screen;
5 is a view for explaining the principle of generating a dichotomous bounding box tree;
6 is a view showing a directed border box tree execution screen;
FIG. 7 is an exemplary view illustrating a case in which a dichotomous boundary box tree is generated by applying a mesh division technique and a case in which a dichotomy boundary box tree is generated without applying a mesh division technique.
FIG. 8 is another exemplary diagram illustrating a case of generating a directed boundary box tree by applying a mesh division technique and a case of generating a directed boundary box tree without applying a mesh division technique. FIG.
FIG. 9 is another exemplary diagram illustrating a case of generating a directed boundary box tree by applying a mesh division technique and a case of generating a directed boundary box tree without applying a mesh division technique. FIG.
10 is a diagram illustrating Separation Axis Theorem.

BRIEF DESCRIPTION OF THE DRAWINGS The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings, It can be easily carried out. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail. Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

And throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between. Also, when a component is referred to as " comprising "or" comprising ", it does not exclude other components unless specifically stated to the contrary .

First, briefly, the gist of the present invention, in order to solve the problem that the directional box tree is not generated in a mechanical component having a relatively simple shape, the mesh by applying a mesh splitting technique to the polygon model of the mechanical component By adding the information, we create a directed bounding box tree close to the actual model. The generated collision boundary tree can be used to perform a reliable collision check.

1A and 1B are diagrams illustrating an embodiment of a collision inspection system of a polygon model to which the present invention is applied.

As shown in FIG. 1A, the collision detection system of a polygon model to which the present invention is applied includes a keyboard 12 which is an input device for inputting data such as a computer 11, a user command, and the like, which performs operations required for the present invention. And a printer 13, which is an output device for outputting a mouse 13 and an operation result.

As shown in FIG. 1B, the computer 11 of the polygonal model collision inspection system to which the present invention is applied includes a central processing unit 15, a main memory device 16 connected to the central processing unit 15, An auxiliary memory device 17 connected to the main memory device 16 and a peripheral device 18 connected to the main memory device 16 are provided.

As described above, the collision detection system of the polygon model to which the present invention is applied includes a central processing unit 15 that controls and manages the overall operation of the computer, and stores a program executed in the central processing unit 15 and is used while performing a task. Alternatively, the main memory device 16 and the auxiliary memory device 17 for storing various data generated while performing a job, the input / output devices 12 to 14 for inputting / outputting data with a user, and a communication interface for Peripheral device 18 is included.

In addition, the auxiliary memory device 17 serves to store a large amount of data, and the input / output devices 12 to 14 are general keyboards 12, mice 13, and display devices (touch screens are input / output devices). Used as a device), and a printer 14 and the like.

However, since the computer hardware environment having the configuration as described above is only a technique well known in the art, detailed description thereof will be omitted herein. However, in the main memory device 16 of the hardware system as described above, mesh information is added to a polygon model by applying a mesh segmentation method, a frankincense boundary box tree is generated using the added mesh information, and the generated frankincense boundary. A collision checking algorithm of a polygon model that performs collision checking using a box tree is stored, and is performed under the control of the CPU 15. The collision detection algorithm of the polygon model will be described in detail with reference to FIG. 2 as follows.

2 is a flowchart illustrating a collision detection method of a polygon model using a dichotomous boundary box tree and a mesh segmentation method according to the present invention.

First, mesh information (geometric information, that is, grid information of a polygonal model) is added to the polygonal model 201 of a mechanical component having a relatively simple shape by applying a mesh division technique (202).

Here, the mesh segmentation technique refers to a technique of approximating a given initial line segment or mesh to a smooth curve or surface through a continuous segmentation operation.

In other words, the mesh segmentation technique creates a new point on the side of each polygon of the original mesh shape and connects the points to create a new mesh. For example, as shown in FIG. 3, the mesh splitting technique generates five new points on the sides of two polygons of the original mesh shape and connects the five points to generate eight new meshes.

In addition, the present invention serves to add a mesh shape (mesh information) to the polygonal model of the machine part with less mesh shape by applying the mesh division technique to the polygonal model of the machine part. 4 is a diagram illustrating an actual mesh division execution screen, and shows a mesh form divided by applying a mesh division technique to an initial mesh form.

Thereafter, the directional boundary box tree is generated using the added mesh information (geometric information, that is, grid information of the polygon model) (203).

At this time, the diversion boundary box is separated by using geometric information, that is, grid information of the polygon model, to generate the diversion boundary box tree. Here, when dividing the dicing boundary box once using geometric information (that is, grid information of the polygon model), two diversion boundary boxes are generated, and when dividing twice, four diversion boundary boxes are generated, and n times (n Is divided into two natural numbers), creating as many as 2 ⁿ mastic boxes. The collision detection can be performed using the generated omnidirectional boundary tree.

Here, as shown in FIG. 5, when the dividing the dividing boundary box using geometric information (that is, the grid information of the polygon model), the dividing boundary box is generated by dividing it into the longest axis in the mesh. FIG. 6 is a diagram illustrating an execution window of a direc- tive boundary box tree, and illustrates a direc- tion boundary box tree generated using a mesh form divided by applying a mesh division technique.

In this way, when mesh information is applied to a polygon model to add mesh information, a directional box tree similar to a real model can be generated. An example thereof will be described with reference to FIGS. 7 to 9.

FIG. 7 is an exemplary view illustrating a case in which the dichotomous boundary box tree is generated by applying the mesh division technique and a case in which the dichotomy boundary box tree is generated without applying the mesh division technique.

As shown in FIG. 7, the shape of FIG. 7 is simple, and thus, when the mesh segmentation method is not applied, the directional boundary tree close to the actual model cannot be generated. However, when applying the mesh segmentation technique, it is possible to generate a directed boundary box tree close to the actual model.

FIG. 8 is another exemplary diagram illustrating a case of generating a directed boundary box tree by applying a mesh division technique and a case of generating a directed boundary box tree without applying a mesh division technique.

As shown in FIG. 8, the shape of FIG. 8 is a shape of a nut. When the mesh splitting technique is not applied, the generated dividing boundary box tree does not include the shape of a hole. In other words, it is not possible to create a directional tree close to the actual model. However, when the mesh segmentation technique is applied, the mastic box tree contains the shape of the hole. In other words, it is possible to generate a directional tree close to the actual model.

FIG. 9 is another exemplary diagram illustrating a case of generating a directed boundary box tree by applying a mesh division technique and a case of generating a directed boundary box tree without applying a mesh division technique.

As shown in FIG. 9, the shape of FIG. 9 is a rather complicated shape, and when the mesh splitting technique is not applied, it is difficult to generate the dicing box tree close to the actual model. However, we can see that when we use the mesh splitting technique, we can create a dichotomous bounding tree close to the actual model.

As such, the three embodiments illustrated in FIGS. 7 to 9 show that the dicing box tree is generated close to the actual model when the mesh segmentation technique is applied.

Thereafter, collision detection is performed using the generated omnidirectional boundary tree (204). In this case, collision inspection using the dicing boundary box tree is performed by using the separation axis theory.

FIG. 10 illustrates the collision inspection principle of the dielectric boundary box using the Separation Axis Theorem. Here, the separation axis theory is a method of collision detection by projecting the dicing box on the axis. Equation 1 below can be used to examine the collision between the frankincense boundary box. The principle of impulse inspection between the mastic box is equally applicable to the mastic box tree.

은 투영된 축에서 유향경계상자 사이의 거리, r_a는 축에 투영된 유향경계상자 A의 반지름 거리, r_b는 축에 투영된 유향경계상자 B의 반지름 거리를 나타낸다.Where T is the center distance between the dicing box, L is the axis projected,

Is the distance between the mound box on the projected axis, r _a is the radius distance of the mound box A projected on the axis, and r _b is the radius distance of the mound box B projected on the axis.

At this time, if the above Equation 1 is satisfied, it is determined that no collision has occurred. If the above Equation 1 is not satisfied, it is determined that a collision has occurred.

As described above, in general, when generating a Boundary Boundary box tree in a concave polygonal model with little geometric information, it is not generated too largely or smoothly than the shape of the actual model. By creating a box tree, you can create a directional box tree similar to the actual model geometry.

By performing a collision test using a directed boundary box tree having a shape close to the actual model thus generated, a reliable collision test result can be derived.

As described above, the present invention has been developed for use in determining the optimal disassembly order of an assembly by using the collision test result by performing the collision test reliably by using the directional box tree having a shape close to the actual model. The disassembly sequence of the assembly can be inspected in the virtual space during the design phase to be integrated into maintenance simulation or design verification software.

On the other hand, the collision detection method of the polygon model using the dichotomous boundary box tree and the mesh segmentation method according to the present invention as described above can be implemented in the form of program instructions that can be executed by various computer means to be recorded on a computer readable medium. have. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the media may be those specially designed and constructed for the purposes of the present invention, or they may be of the kind well-known and available to those having skill in the computer software arts. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tape, optical media such as CD-ROMs, DVDs, and magnetic disks, such as floppy disks. Magneto-optical media, and hardware devices specifically configured to store and execute program instructions, such as ROM, RAM, flash memory, and the like. The medium may be a transmission medium such as an optical or metal line, a wave guide, or the like, including a carrier wave for transmitting a signal designating a program command, a data structure, or the like. Examples of program instructions include not only machine code generated by a compiler, but also high-level language code that can be executed by a computer using an interpreter or the like. The hardware device may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, Various permutations, modifications and variations are possible without departing from the spirit of the invention.

Therefore, the scope of the present invention should not be construed as being limited to the embodiments described, but should be determined by the scope of the appended claims, as well as the appended claims.

The present invention can be used for collision inspection of mechanical part polygon models and the like.

11: computer 12: keyboard
13: mouse 14: printer
15: central processing unit 16: main memory unit
17: auxiliary storage device 18: peripheral device

Claims (4)

In the collision detection method in the collision detection system,
Adding mesh information by applying a mesh division technique to the polygon model;
Generating a dichotomous bounding box tree by using the added mesh information; And
Collision check performing step of performing a collision check using the generated omnidirectional boundary box tree
Collision checking method comprising a.
The method of claim 1,
The directed border box tree generation step,
The collision detection method of generating a dividing boundary box tree by dividing the dicing boundary box into the longest axis using geometric information of the polygon model (ie, grid information of the polygon model).
The method according to claim 1 or 2,
The mesh information,
And the geometric information of the polygon model (ie, the grid information of the polygon model).
In a collision detection system with a processor,
Adding mesh information by applying a mesh division technique to the polygon model;
Generating a dichotomous bounding box tree by using the added mesh information; And
Collision check performing step of performing a collision check using the generated omnidirectional boundary box tree
A computer-readable recording medium having recorded thereon a program for realizing this.

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