KR20160123750A - Apparatus and method for generating thickness model for 3d printing - Google Patents

Abstract

The present invention relates to an apparatus and a method of generating a thickness model which reduces manufacturing costs of high-quality model data by setting the thickness. To achieve this, the method to generate the thickness model of the present invention comprises: a step of preparing a three-dimensional sample model including a predetermined thick model data; a step of generating a three-dimensional modification model by modifying an exterior of the three-dimensional sample model based on a modification information; and a step of generating a thickness model of the three-dimensional modification model based on an exterior modification degree between the three-dimensional sample model and the three-dimensional modification model.

Description

[0001] APPARATUS AND METHOD FOR GENERATING THICKNESS MODEL FOR 3D PRINTING [0002]

The present invention relates to an apparatus and method for generating a thickness model, and more particularly to an apparatus and method for generating a thickness model using a minimum number of samples or a three-dimensional template thickness model.

Recently, technologies for three-dimensional printing are attracting attention. Generally, such three-dimensional printing requires three-dimensional model data compatible with various three-dimensional printers. Specifically, the three-dimensional model data means a three-dimensional model having a common thickness or a three-dimensional model filled with the inside. Generally, three-dimensional printing is achieved by outputting materials in a laminated manner. Here, in order to perform printing by the lamination method, thickness information according to the characteristics of the material is required.

Since the conventional 3D model for 3D graphics rendering is mostly composed of only one surface for rendering without thickness information, it is difficult to use it in 3D printing immediately. In some resin extrusion molding (FDM) type printers, the thickness of the filament, which is the material, is set as the default value, and the three-dimensional model with no thickness can be printed. However, Most 3D printers, such as SLS, PolyJet, and Mask Projection Image Curing (DLP), are not capable of printing three-dimensional cross-section models without internal information.

Since the existing three-dimensional model data is mainly designed to render data on the screen, the limitation of data to be provided for printing and the conditions (matching of normal vector direction, elimination of bad edge, , Removal of noise shells, provision of thickness information, etc.).

Therefore, in order to print an existing three-dimensional model in three dimensions, it is necessary to check all the aforementioned items and modify the data by using a separate software. In recent years, software that confirms the possibility of three-dimensional printing of a three-dimensional model in the web and cloud environments has been introduced. In the case of a simple model, error checking and slight correction are possible. However, in order to output high- , Requires specialized knowledge and experience, making it difficult for ordinary users to access easily.

Given the cross-sectional three-dimensional model, there are offset generation techniques used mainly in CAD (Computer-Aided Design) field as a conventional technique of generating thickness. In this method, for a given model, the user automatically generates the thickness according to the input offset value while grasping the physical characteristics of the model, for example, length, width, width, bending and overlap, etc., By informing the cause, the user is guided to modify the input value. Therefore, each model requires a separate task, and it is necessary to understand the physical concept and characteristics of the three-dimensional model and to constantly find the appropriate value through the offset input test, thereby improving the convenience of the engineer. It is difficult to use.

Another way to produce 3D model data considering 3D printing characteristics is to create a new model based on the understanding and understanding of the concept and characteristics of 3D printing by existing designers or artists. This method is also difficult to generate a large amount of data, and it is difficult for professional designers to work on all the personalized data required by the spread of the 3D printer. Particularly, since the thickness of the model for three-dimensional printing is directly related to the amount of the material used, it is possible to reduce the cost required to generate the inner thickness similar to the outer shape as much as possible. If you make the interior full for convenience, you can automatically create a grid structure depending on the type of the 3D printer, or you can use a lot of materials to fill the shape, and even print unwanted forms . Therefore, there is a problem in that it is necessary to work on the thickness of all models in order to obtain a practical and economical output.

Prior art relating to the present invention is disclosed in US Patent Application Publication No. 2007-0078590 (Method and System for Creating Model Data), 2004, RW Sumner and J. Poppovic, ACM Transactions on Graphics (pages 399 to 405) "Deformation Transfer for Triangle Meshes", "A 3D Surface Offset Method for STL-format Models", published by Rapid Prototyping Journal (pp. 133-141) by X. Qu and B. Stucker in 2003, and Y. Chen, H. Wang, DW Rosen, and J. Rossignac, "A Point-Based Offsetting Method of Polygonal Meshes "

It is an object of the present invention to provide an apparatus and method for generating a thickness model that can be easily used by a general user and can reduce manufacturing cost of high-quality model data through thickness setting.

According to another aspect of the present invention, there is provided a method of generating a thickness model, comprising: preparing a three-dimensional sample model including predetermined thickness model data; Generating a three-dimensional deformation model by modifying the three-dimensional sample model based on the deformation information; And generating a thickness model of the three-dimensional deformation model based on the degree of external deformation between the three-dimensional sample model and the three-dimensional deformation model.

The generating of the three-dimensional deformation model may include: expressing the three-dimensional sample model and the deformation information using a determinant; And calculating a determinant of the three-dimensional deformation model by calculating a matrix equation for the three-dimensional sample model and the deformation information.

In addition, the step of calculating the determinant can be performed by a linear optimization method.

Also, the step of generating the thickness model may be performed by subtracting the determinant of the outer deformed model among the three-dimensional deformed models in the determinant for the three-dimensional deformed model.

The step of preparing the 3D sample model may further include converting the 3D sample model into a triangle mesh model including the vertex set and vertex connectivity information.

In addition, the step of generating the three-dimensional deformation model may further comprise setting a correlation between the inner surface and the outer surface of the three-dimensional sample model.

In addition, the step of establishing the correlation may be performed by performing triangulation based on the outer deformed reference point of the three-dimensional sample model and an arbitrary number of vertices selected from the inner surface and the outer surface.

In addition, the step of establishing the correlation can be accomplished by calculating the minimum distance between the inner and outer vertices of the selected vertices.

According to an aspect of the present invention, there is provided a thickness model generation apparatus for preparing a three-dimensional sample model including predetermined thickness model data and modifying a three-dimensional sample model based on deformation information, And generating a thickness model of the three-dimensional deformation model based on the degree of external deformations between the three-dimensional sample model and the three-dimensional deformation model.

Also, the processor may calculate the determinant for the three-dimensional deformation model by expressing the three-dimensional sample model and the deformation information in a matrix form, and computing a matrix equation for the three-dimensional sample model and deformation information.

In addition, the processor can calculate the determinant using a linear optimization technique.

In addition, the processing unit can generate the thickness model by subtracting the determinant of the outer deformed model among the three dimensional deformed models in the determinant for the three dimensional deformed model.

The processor may also convert the three-dimensional sample model into a triangular mesh model containing vertex sets and vertex connectivity information.

Further, the processing unit can set a correlation between the inner surface and the outer surface of the three-dimensional sample model.

In addition, the processing unit can set the correlation between the inner surface and the outer surface by performing triangulation based on the outer deformed reference point of the three-dimensional sample model and an arbitrary number of vertices selected from the inner surface and the outer surface.

The processor can also establish a correlation between the inner surface and the outer surface by calculating a minimum distance between vertices selected from the inner surface and the outer surface.

According to the thickness model generating apparatus and method of the present invention, when the user deforms only the outer shape of the example thickness model without knowing the information about the inner thickness of the three-dimensional model or the physical characteristics of the object, 3-dimensional printing can be effected.

In addition, the present invention can reduce the production cost of high-quality model data capable of three-dimensional printing in accordance with the diversification / dissemination of three-dimensional printers in the future, and also allows more users to easily create personalized three- And can contribute to output to the printer.

1 is a block diagram of a thickness model generating apparatus according to an embodiment of the present invention.
2 is a block diagram of a processing unit according to an embodiment of the present invention.
3 is a diagram for explaining an example of converting a 3D sample model into a triangular mesh model through a thickness model generating apparatus according to an embodiment of the present invention.
4 is a view for explaining an example of setting a correlation between an inner surface and an outer surface through a thickness model generating apparatus according to an embodiment of the present invention.
5A to 5D are views for explaining an example of generating a thickness model through a thickness model generating apparatus according to an embodiment of the present invention.
6 is a flowchart illustrating a method of generating a thickness model according to an embodiment of the present invention.
7 is a flowchart of a step of preparing a three-dimensional sample model according to an embodiment of the present invention.
FIG. 8 is a flowchart of a step of generating a three-dimensional deformation model according to an embodiment of the present invention.

The present invention will now be described in detail with reference to the accompanying drawings. Hereinafter, a repeated description, a known function that may obscure the gist of the present invention, and a detailed description of the configuration will be omitted. Embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art. Accordingly, the shapes and sizes of the elements in the drawings and the like can be exaggerated for clarity.

Hereinafter, a thickness model generation apparatus 100 according to an embodiment of the present invention will be described. 1 is a block diagram of an apparatus 100 for generating a thickness model according to an embodiment of the present invention. The thickness model generation apparatus 100 according to an exemplary embodiment of the present invention generates a three-dimensional output model that a user desires to output using a three-dimensional sample model stored in the storage unit 10. Specifically, the apparatus 100 for generating a thickness model according to an embodiment of the present invention calculates a three-dimensional output model (hereinafter referred to as a three-dimensional deformation model) on the basis of deformation information input from a user . Also, since the predetermined thickness model data is stored together with the three-dimensional sample model, when the user deforms the outer shape of the three-dimensional sample model, the inner shape and the thickness thereof may be deformed together. For this, the apparatus 100 for generating a thickness model according to an embodiment of the present invention may include a controller 110 and a processor 120.

The processing unit 120 generates a three-dimensional deformation model under the control of the control unit 110 and generates a thickness model therefor. A process of generating a three-dimensional deformation model through the processing unit 120 and generating a thickness model therefor is as follows.

First, the processing unit 120 prepares a three-dimensional sample model. Here, the three-dimensional sample model may include predetermined thickness model data as a model received from the storage unit 10 or an external server (not shown). That is, the three-dimensional sample model itself represents a model capable of three-dimensional printing. Further, the three-dimensional sample model may further include information capable of distinguishing between the outer surface and the inner surface, color information, and texture information. The number of three-dimensional sample models stored in the storage unit 10 or the external server (not shown) is one or more and is not limited to a specific number. However, even if only one sample model exists, it is possible to generate various types of deformation models through modification of the corresponding sample model, as described below. For example, if a part of a model outline with a spherical shape is modified to have a rabbit ears shape, an inner surface having a shape that is as close as possible to the outer shape and maintains a constant (minimum or maximum) gap with the outer surface can be created .

Also, with respect to the thickness of the three-dimensional sample model, when the three-dimensional sample model has the minimum thickness, the model newly generated according to the variation is a model having the minimum thickness. Conversely, when the three-dimensional sample model has the maximum thickness, the newly generated model will be a model with the maximum thickness.

Thereafter, the processing unit 120 can convert the three-dimensional sample model into a triangular mesh model (see FIG. 3). Here, the reason why the three-dimensional sample model is converted by the triangular mesh model is that most of the graphic operations performed in the computer are optimized for the triangle. Accordingly, the transformation of the three-dimensional sample model can be considered for more efficient processing. Here, the conversion to the triangular mesh model can be performed through various methods such as a parametric curve-based method or a polygonal mesh-based method. However, in order to perform 3D printing, a 3D triangular mesh model having a surface set representing the vertex and vertex connectivity information is finally required. Therefore, it is desirable that the transformation is performed by a method capable of implementing the 3D triangle mesh model.

Thereafter, the processing unit 120 can establish a correlation between the inner surface and the outer surface of the three-dimensional sample model. The reason for setting the correlation between the inner surface and the outer surface through the processing unit 120 is that if the outer surface and the inner surface are independent of each other and no relationship is set, . In other words, when no relation is set in this way, there is a problem that deformation of another surface can not be automatically controlled based on one surface. Accordingly, the present invention also contemplates ways of establishing a correlation between an inner surface and an outer surface.

There are two methods for setting the correlation between the inner surface and the outer surface. The first method is to select arbitrary number of vertices on the inner and outer surfaces of the triangular mesh model, and to perform triangulation based on the selected vertices. The second method is to calculate the correspondence between vertices by calculating the minimum distance between the inner surface and the vertexes of the outer surfaces. In the second method, the calculation for the correspondence between vertices can be made according to the difference in the number of vertices included in the inner surfaces and the outer surfaces. Thus, one-to-one, many-to-one, and one-to-many mapping relationships can be created, and the amount of computation is proportional to the total number of vertices. Further, in addition to the above methods, additional methods can be applied to the manner of establishing the relationship between the triangular mesh set for the inner surface and the outer surface.

Thereafter, the processing unit 120 can generate the three-dimensional deformation model by modifying the outer shape of the three-dimensional sample model based on the deformation information. Here, the deformation information indicates information used in transformation from a three-dimensional sample model through a user's input to a form desired by the user. In addition, the processing unit 120 may generate a 3D transformation model based on a transformation gradient-based linear optimization framework for the transformation. Here, the three-dimensional deformation model can be expressed by Equation 1 below. The reason why the three-dimensional deformation model can be generated as shown in Equation (1) is that a correlation is established between the inner surface and the outer surface through the processing unit 120 from above. Accordingly, even if the external shape is changed through the deformation information, the relationship in which the internal surface is also changed can be maintained.

In Equation (1), A represents a three-dimensional sample model and X represents deformation information. That is, the 3D model and the deformation information are calculated in the form of a matrix, and the 3D model and the deformation information are calculated, and the 3D deformation model can be derived. Here, the thickness, that is, the internal thickness model can be derived by subtracting the external deformed model from the three-dimensional deformed model in the above-described three-dimensional deformed model. This can be expressed by the following equation (2).

In the equation (2), T'tar is an inner thickness model (hereinafter, a thickness model), S'rc is an outer shape of a three-dimensional sample model, and S'tar is a three-dimensional outer model. Deformation of the internal model from the equation (2) that is, _in the X can be derived, the inner surface of the 3D model, i.e., the sample, adding the X _in each of the vertex values T'src the automatically generated according to the modified appearance A thickness model can be obtained.

As mentioned above, if the three-dimensional sample model has a minimum thickness model or a minimum thickness model, then the thickness of the three-dimensional deformation model will also be minimized or maximized. However, the present invention can further adjust the thickness through the user's input by further including thickness adjustment parameters in the deformation information. That is, the processing unit 120 may apply the thickness adjustment parameter to the above-mentioned thickness model, which can be achieved through the interpolation method. The deformation information may also include a plurality of thickness adjustment parameters, which may be applied at various positions or at various levels.

Thereafter, the processing unit 120 restores the three-dimensional deformation model back to its original shape. Specifically, the processing unit 120 has performed the above-described processing after converting the three-dimensional sample model into the triangular mesh model. For example, if the original three-dimensional sample model was a rectangular model, it means restoring it back to a rectangular model.

Thereafter, the processing unit 120 may store the finally generated model data in a file format supported by the three-dimensional printer. The currently supported common formats are mainly STL, FBX, etc. If the profile information of the printer is available, it can also be converted into the printer's own format.

An example of the results through the above-mentioned processing (converting a three-dimensional sample model to a three-dimensional deformation model) is shown in Figs. 5A to 5D. 5A and 5B show an example of a three-dimensional sample model, and FIGS. 5C and 5D show a modified three-dimensional deformation model based on deformation information. That is, when the user receives the three-dimensional sample model shown in FIGS. 5A and 5B, if the user deforms the desired three-dimensional model as shown in FIG. 5C, the thickness information can be automatically generated as shown in FIG. 5D .

In this way, even when the user is a general user, that is, even if the user does not know the information about the internal thickness of the three-dimensional model or the physical characteristics of the object, if the user only deforms the external shape of the example model, A thickness model that can be easily printed in three dimensions is generated.

2 is a block diagram of a processing unit 120 according to an embodiment of the present invention. As described above, the processing unit 120 transforms a three-dimensional sample model based on deformation information input from a user, thereby generating a desired three-dimensional deformation model and generating thickness information therefrom. The processing unit 120 may include a conversion module 121, a relationship setting module 122, a modified model generation module 123, a thickness model generation module 124, and a restoration module 125. Here, each of the components included in the processing unit 120 is obtained by separating the features through the processing unit 120 by function. That is, it should be understood that the above-described configurations are not intended to be all included in the processing unit 120, but for the sake of understanding. In the following description, parts overlapping with those described above are omitted.

The conversion module 121 converts the three-dimensional sample model stored in the storage unit 10 into a triangular mesh model. As described above, the three-dimensional sample model is a model stored in the storage unit 10 or an external server, and is defined as a model having predetermined thickness information. Also, the transformation to the triangular mesh model is performed because most of the graphical operations are optimized for triangles, so that the present invention can provide an efficient and optimized transformation process. In addition, the transformation method through the transformation module 121 is not limited to a specific method as long as it is a method capable of implementing a three-dimensional triangular mesh model having a surface set representing vertex set and vertex connectivity information.

The relationship setting module 122 functions to set a correlation between the inner surface and the outer surface of the three-dimensional sample model converted into the triangular mesh model. The correlation setting method through the relation setting module 122 can be roughly divided into two methods. The first method is to select any number of vertices on the inner and outer surfaces of the triangular mesh model and to perform triangulation based on the selected vertices. The second method is to calculate the correspondence between vertices by calculating the minimum distance between the inner surface and the vertexes of the outer surfaces. The description of these methods has been described in detail with reference to FIG. 1, and a further description thereof will be omitted.

The deformation model generation module 123 generates the deformation model based on the deformation information input through the input unit 20 and the three-dimensional sample model in which the correlation between the inner surface and the outer surface is set through the relationship setting module 122 Function. Specifically, the deformation model generation module 123 can generate a deformation model by expressing the three-dimensional sample model and the deformation information in a matrix form, respectively, and calculating them. Such determinant generation and calculation can be performed using a strain gradient-based linear optimization technique.

The thickness model generation module 124 functions to generate a thickness model of the three-dimensional deformation model. Specifically, the thickness model generation module 124 derives a thickness model by subtracting the determinant of the external deformed model among the three-dimensional deformed models in the determinant of the three-dimensional deformed model. A detailed description thereof has been given above in detail, so that further explanation is omitted.

The restoration module 125 restores the three-dimensional deformed model in the form of a triangular mesh model to the original model.

6 is a flowchart illustrating a method of generating a thickness model according to an embodiment of the present invention. Hereinafter, a method of generating a thickness model according to an embodiment of the present invention will be described with reference to FIG.

First, a step of preparing a three-dimensional sample model (S110) is performed. The three-dimensional sample model is a sample model prepared considering the three-dimensional printing attribute, and may include predetermined thickness model information. In addition, the 3D sample model may further include information and texture information that can distinguish between the outside and the inside.

Thereafter, a three-dimensional deformation model is generated by modifying the three-dimensional sample model based on the deformation information input from the user (S120). The three-dimensional deformation model generated in step S120 may be expressed as a determinant using a deformation gradient-based linear optimization technique.

Thereafter, a step (S130) of creating a thickness model of the three-dimensional deformation model is performed based on the degree of external deformation between the three-dimensional sample model and the three-dimensional deformation model. More specifically, the step S130 can be obtained by subtracting the outer deformed model from the three-dimensional deformed model in the three-dimensional deformed model.

FIG. 7 is a flowchart of a step (S110) of preparing a three-dimensional sample model according to an embodiment of the present invention. Hereinafter, with reference to FIG. 7, step S110 will be described.

First, a step S111 of receiving a three-dimensional sample model is performed. The 3D sample model can be received from a storage unit or an external server.

Thereafter, a step (S112) of converting the three-dimensional sample model into the triangular mesh model is performed. As mentioned earlier, most graphics operations are optimized for triangles. Accordingly, the present invention performs a conversion process of a three-dimensional sample model. For example, if the three-dimensional sample model was a rectangular model, then this three-dimensional sample model can be transformed into a triangular mesh model. In addition, the method of performing step S112 is not limited to a specific method as long as it is a method capable of generating a three-dimensional triangular mesh model having a surface set representing vertex set and vertex connectivity information.

FIG. 8 is a flowchart of a step of generating a three-dimensional deformation model according to an embodiment of the present invention.

First, a step S121 of setting a correlation between the outer surface and the inner surface of the three-dimensional sample model converted into the triangular mesh model is performed. As described above, the reason for carrying out the step S121 is that if the outer surface and the inner surface are independent of each other and no relation is set, two different models exist. In other words, when no relation is set in this way, there is a problem that deformation of another surface can not be automatically controlled based on one surface.

Accordingly, a correlation setting process is required through step S121. In step S121, an arbitrary number of vertices are selected from outer contour reference points of the triangular mesh model, inner and outer surfaces, and triangulation is performed with respect to the selected vertices, or between vertices of inner and outer surfaces And calculating the correspondence between vertices by calculating the minimum distance. Since the description of these methods has been described in detail above, further explanation is omitted.

Thereafter, step S122 of receiving deformation information input from the user is performed. As mentioned above, the deformation information is based on a three-dimensional sample model and represents the information used for transformation into the final model desired by the user.

Thereafter, a step S123 of generating a three-dimensional deformation model based on the three-dimensional sample model and the deformation information is performed. Specifically, step S123 may be performed by converting the three-dimensional sample model and the deformation information into a determinant and calculating them, respectively. Since the description of step S123 has been described in detail above, a further explanation thereof will be omitted,

As described above, an optimal embodiment has been disclosed in the drawings and specification. Although specific terms have been employed herein, they are used for purposes of illustration only and are not intended to limit the scope of the invention as defined in the claims or the claims. Therefore, those skilled in the art will appreciate that various modifications and equivalent embodiments are possible without departing from the scope of the present invention. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

100: Thickness model generating apparatus 110:
120:

Claims (1)

Preparing a three-dimensional sample model including predetermined thickness model data;
Generating a three-dimensional deformation model by modifying the three-dimensional sample model based on deformation information; And
And generating a thickness model of the three-dimensional deformation model based on the degree of external deformation between the 3D sample model and the 3D deformation model.

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