KR20170143346A - 3D printing method for a plurality of 3D objects and apparatus thereof - Google Patents

Abstract

The present invention relates to a method and an apparatus for three-dimensional printing of a plurality of three-dimensional objects. The three-dimensional printing method according to an embodiment of the present invention comprises the steps of: determining respective bounding boxes for a plurality of three-dimensional meshes; rotating bounding boxes of which one side is inclined to a reference line among the respective bounding boxes such that one side becomes parallel to the reference line; disposing the bounding boxes of which one side is parallel to the reference line within a printing space such that the bounding boxes of which one side is parallel to the reference line do not overlap with each other; disposing three-dimensional meshes corresponding to the respective bounding boxes in a region where the bounding boxes corresponding to the concerned three-dimensional meshes are disposed; and printing the plurality of three-dimensional objects using the disposed three-dimensional meshes. The three-dimensional printing method according to embodiments of the present invention can improve three-dimensional printing efficiency by enabling the plurality of three-dimensional objects to be three-dimensionally printed at the same time.

Description

[0001] The present invention relates to a method and apparatus for 3D printing of a plurality of 3D objects,

Embodiments of the present invention are directed to a method and apparatus for 3D printing of a plurality of 3D objects.

Typical three-dimensional printers require preparations for printing 3D objects. For example, it is necessary to preheat the 3D printer to an appropriate temperature, or clean the traces of previously printed 3D objects. If a plurality of 3D objects are to be printed, if the 3D object is printed each time one 3D object is printed, the printing efficiency may be greatly reduced.

US Patent Publication No. 2014/0052415 (Partitioning models into 3D-printable components)

Embodiments of the present invention provide a method for 3D printing of a plurality of 3D objects at the same time.

Embodiments of the present invention provide a way to automatically place a plurality of 3D meshes within a printing space.

A 3D printing method according to an exemplary embodiment of the present invention includes: determining a bounding box of each of a plurality of 3D meshes; Rotating one of the bounding boxes inclined at one side of the bounding box so that one side of the bounding box is parallel to the reference line; Placing in a printing space such that bounding boxes parallel to one side of the baseline do not overlap each other; Placing a 3D mesh corresponding to each bounding box in an area in which a bounding box corresponding to the 3D mesh is disposed; And printing a plurality of 3D objects using the arranged 3D meshes.

In one embodiment, the step of determining the bounding box comprises: calculating a convex hull of the 3D mesh; And determining a bounding box of the smallest area surrounding the convex shell.

In one embodiment, the step of arranging the bounding boxes may include determining a placement order of the bounding boxes based on at least one of a length and an area of sides of the bounding boxes.

In one embodiment, the step of arranging the bounding boxes may include: determining placement candidate regions of the N-th bounding box, based on the edges of the bounding boxes arranged from 1 to N-1; Calculating an area of a rectangle surrounding all N bounding boxes when an N-th bounding box is arranged in the placement candidate region for each of the placement candidate regions; And placing an Nth bounding box in the placement candidate region where the area of the rectangle is calculated to be the smallest.

In one embodiment, calculating the area of the rectangle may include calculating the area of the rectangle while rotating the N-th bounding box by 90 degrees.

In one embodiment, the printing space is rectangular and the baseline may be parallel to one side of the printing space.

In one embodiment, the method may further comprise adjusting the size of the bounding box taking into account the spacing between the 3D meshes.

In one embodiment, the step of disposing the 3D mesh may include disposing the 3D mesh in consideration of the angle at which the bounding box corresponding to the 3D mesh is rotated.

A printing apparatus according to an embodiment of the present invention includes a processor and a memory. The memory may store a plurality of 3D meshes and instructions for performing 3D printing using the plurality of 3D meshes. Wherein the instructions, when executed by the processor, cause the processor to determine a bounding box of each of the plurality of 3D meshes, rotate a bounding box that is sloped to one of the bounding boxes of the respective bounding box, The 3D mesh corresponding to each of the bounding boxes is disposed in an area in which the bounding box corresponding to the corresponding 3D mesh is disposed. The bounding boxes corresponding to the bounding boxes are arranged in the printing space so that the bounding boxes, And may include instructions for printing a plurality of 3D objects using the arranged 3D meshes.

In one embodiment, the instructions may include instructions to calculate a convex hull of a 3D mesh and to determine a bounding box of a minimum area surrounding the convex hull.

In one embodiment, the instructions may include instructions to calculate a convex hull of a 3D mesh and to determine a bounding box of a minimum area surrounding the convex hull.

In one embodiment, the instructions determine placement candidate regions of the N-th bounding box based on the corners of the first to the (N-1) th bounding boxes, and assign N An area of a rectangle surrounding all of the N bounding boxes is calculated, and an Nth bounding box is placed in a placement candidate area where the area of the rectangle is calculated to be the smallest.

In one embodiment, the instructions may include instructions to calculate an area of the rectangle with the Nth bounding box rotated 90 degrees.

In one embodiment, the instructions may include instructions to adjust the size of the bounding box in consideration of the spacing between the 3D meshes.

In one embodiment, the instructions may include instructions for placing the 3D mesh in consideration of the rotated angle of the bounding box corresponding to the 3D mesh when the 3D mesh is disposed.

According to embodiments of the present invention, since a plurality of 3D objects can be 3D-printed at the same time, 3D printing efficiency can be improved.

FIG. 1 is a flowchart illustrating a 3D printing method according to an exemplary embodiment of the present invention. FIG.
2 (a) to 2 (c) are diagrams for explaining an example of determining a bounding box,
3 is an exemplary view for explaining an example of rotating a bounding box according to an embodiment of the present invention,
FIG. 4 is a flowchart illustrating a method of arranging a bounding box according to an embodiment of the present invention. FIG.
FIG. 5 is an exemplary view for explaining a placement order determination of a bounding box according to an embodiment of the present invention;
6 (a) to 6 (e) are views for explaining an example of a bounding box arrangement according to an embodiment of the present invention,
FIG. 7 is a block diagram for explaining a 3D printing apparatus according to an embodiment of the present invention; FIG.

In the following description of the embodiments of the present invention, a detailed description of known functions and configurations incorporated herein will be omitted when it may make the subject matter of the present invention rather unclear.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

1 is a flowchart illustrating a 3D printing method according to an embodiment of the present invention. Depending on the embodiment, at least one of the steps shown in Fig. 1 may be omitted.

In step 101, the 3D printing device may load a plurality of 3D meshes used for 3D printing. The 3D mesh may be a data file used for printing 3D objects that are the result of 3D printing.

In step 103, the 3D printing device may determine the bounding box of each 3D mesh. In order to determine the bounding box of one 3D mesh, the 3D printing apparatus can calculate the convex hull of the corresponding 3D mesh by projecting all the vertices of the 3D mesh to the reference plane. Here, the reference surface may be a bottom surface of the printing space, or a horizontal surface of the bottom surface of the printing space. The 3D printing apparatus can calculate a plurality of bounding boxes surrounding convex shells. The 3D printing apparatus can determine the bounding box having the smallest area among the calculated plurality of bounding boxes as the bounding box of the corresponding 3D mesh. The bounding box may be in the form of a two-dimensional rectangle. An example of determining a bounding box will be described with reference to FIGS. 2 (a) to 2 (c).

2 (a) to 2 (c) are diagrams for explaining an example of determining a bounding box.

Assume that the convex shell 202 is calculated as shown in Fig. 2 (a) for any 3D mesh. As described above, the 3D printing apparatus can calculate a plurality of bounding boxes surrounding the convex shell 202. As a result of the calculation, it is assumed that the bounding boxes 204 and 206 as shown in FIGS. 2B and 2C are calculated. For convenience of explanation, it is assumed that two bounding boxes 204 and 206 are calculated, but three or more bounding boxes may be calculated.

Once the bounding boxes 204, 206 are calculated, the 3D printing device can calculate the area of each of the bounding boxes 204, 206. As a result of the calculation, if the area of the bounding box 206 is smaller than the area of the bounding box 204, the 3D printing apparatus can determine the bounding box 206 as a bounding box of the corresponding 3D mesh.

According to the embodiment, the size of the bounding box can be adjusted in consideration of the interval to be maintained between the 3D meshes. For example, if the interval to be maintained between 3D meshes is d, the length of each side of the bounding box can be increased by d / 2.

Referring again to FIG. 1, in step 105, the 3D printing device may rotate a bounding box that is sloped to one side of the bounding box so that one side of the bounding box is parallel to the baseline.

For example, assume that one side of the bounding box 206 forms an angle of 60 degrees with the baseline 208, as shown in FIG. 2 (c). In this case, the 3D printing apparatus can rotate the bounding box 206 by 60 degrees, as shown in FIG.

Here, the reference line may be a line parallel to one side of the printing space, assuming that the printing space of the 3D printer is rectangular. When the bounding box is rotated, the 3D printing apparatus can store the angle at which the bounding box is rotated (hereinafter referred to as a first rotation angle) corresponding to the bounding box. The first rotation angle can be used when the 3D mesh is placed in the printing space later.

In step 107, the 3D printing device may place the bounding boxes in the printing space so that the bounding boxes do not overlap each other. In placing the bounding boxes, various algorithms (e.g., greedy or branch and bound algorithms, etc.) may be used. As an example, an example of placing bounding boxes using a greedy algorithm will be described in more detail with reference to FIG.

4 is a flowchart illustrating a method of arranging a bounding box according to an embodiment of the present invention. Depending on the embodiment, at least one of the steps shown in Fig. 4 may be omitted.

In step 401, the 3D printing device may determine the placement order of the bounding boxes. In determining the placement order, the 3D printing device may determine the placement order of the bounding boxes in consideration of at least one of the length and the area of sides of the bounding boxes.

For example, assume that three bounding boxes A, B, C are determined, as shown in FIG. Here, the bounding boxes A, B, C are the bounding boxes A, B, C determined for different 3D meshes. The length of the long side of the bounding box A is L1, the length of the long side of the bounding box B is L2, and the length of the long side of the bounding box C is L3. Let L1> L2> L3.

In this case, the 3D printing apparatus determines that the bounding box A having the longest length L1 is to be disposed first, and the bounding box B having the longest length L3 is disposed last Can be determined as follows.

Alternatively, if the relationship between the sides is L1 = L2 > L3 and the area of the bounding box B is greater than the area of the bounding box A, then the 3D printing device may be a bounding box B) to be placed first. That is, the 3D printing apparatus can determine the arrangement order of the bounding boxes A, B, and C by prioritizing the lengths longer than the area. Conversely, the 3D printing device may determine the placement order of the bounding boxes (A, B, C) by prioritizing the area over the length of the long sides.

In step 403, the 3D printing device may determine a placement candidate area in which to place each bounding box to place the bounding boxes within the printing space.

The placement candidate region in which the N-th bounding box is to be placed may be determined based on the corners of the bounding boxes arranged from 1 to N-1th. For example, assume that the bounding box A is disposed in the printing space 602, as shown in Fig. 6 (a). In this case, the placement candidate region of the second bounding box can be determined based on the edge Ap1 located at the right upper end of the bounding box A and the edge Ap2 located at the lower left end of the bounding box A . That is, with respect to the second bounding box, the right lower area Ac1 of the edge Ap1 and the lower right area Ac2 of the edge Ap2 can be determined as the placement candidate areas. The placement candidate regions may be determined in the same manner for the bounding boxes to be placed thereafter.

On the other hand, when N is 1, that is, in the case of the first bounding box A, as shown in Fig. 6 (a) A bounding box A may be disposed.

In step 405, the 3D printing apparatus can calculate the objective function f in each case, assuming that a bounding box is placed in each batch candidate area. The objective function (f) can be defined as Equation (1).

Where S _N is the area of the Nth bounding box, W is the width of the rectangle of the smallest area surrounding the entire bounding box when the Nth bounding box is placed, H is the width of the rectangle enclosing the entire bounding box when placing the Nth bounding box Means the vertical length of the rectangle of minimum area.

That is, when Equation (1) assumes that the Nth bounding box is placed in an arbitrary placement candidate area, Equation (1) can be expressed as Equation (1) where the area of the rectangle surrounding the entire bounding box Denotes calculation of the function f.

For example, in a state where the first bounding box A is disposed as shown in FIG. 6A, the placement candidate region of the second bounding box is divided into an area Ac1 based on the edge Ap1, And the area Ac2 based on the edge Ap2. Suppose that the second bounding box is the bounding box B shown in Fig.

In this case, the 3D printing apparatus can calculate the objective function in each case, assuming that the bounding box B is arranged in the area Ac1 and the area Ac2. At this time, the 3D printing apparatus can calculate the objective function while rotating the bounding box B by 90 degrees.

For example, as shown in FIG. 6 (b), assuming that the bounding box B is arranged without rotating the area based on the edge Ap1, the 3D printing apparatus is arranged so that the rectangle 606b ) Can be calculated by using the horizontal length and the vertical length as parameters.

For example, as shown in FIG. 6C, it is assumed that the 3D printing apparatus rotates the bounding box B by 90 degrees in an area based on the edge Ap1, It is possible to calculate an objective function using the horizontal length and the vertical length of the rectangle 606c as parameters.

Similarly, assuming that the bounding box B is disposed in an area based on the edge Ap2, as shown in Figs. 6 (d) and 6 (e) 606d and 606e may be calculated by using the lateral length and the longitudinal length as parameters.

Referring again to FIG. 4, in step 407, the 3D printing apparatus can arrange the N-th bounding box according to the arrangement state when the objective function is maximized.

For example, among the rectangles 606b, 606c, 606d, and 606e shown in Figs. 6B to 6E, the area of the rectangle 606e shown in Fig. 6E is the smallest Assume that the objective function is maximized in the arrangement state as shown in FIG. 6 (e). Therefore, the 3D printing apparatus can arrange the bounding box B as shown in FIG. 6 (e).

Meanwhile, when the N-th boundary box is rotated by 90 degrees, the 3D printing apparatus can store 90 degrees (hereinafter referred to as a second rotation angle) corresponding to the bounding box, corresponding to the rotation angle of the bounding box. The second rotation angle can be used when the 3D mesh is placed in the printing space later.

Meanwhile, the 3D printing apparatus checks whether the bounding box overlaps with the previously disposed bounding box or out of the printing space when arranging the bounding box, and determines the placement position of the bounding box again if this is the case . For example, as shown in FIG. 6 (c), when the bounding box B is out of the printing space 602, the placement position of the bounding box B can be determined again.

On the other hand, the corner of the N-th bounding box can be used as a reference point for determining the placement candidate region of the (N + 1) -th bounding box. For example, as shown in FIG. 6E, the upper right corner Bp1 and the lower left corner Bp2 of the N-th placed bounding box B are located in the (N + 1) th bounding box And can be used as a reference point for determining the placement candidate region.

Referring again to FIG. 1, in step 109, the 3D printing device may place a 3D mesh corresponding to the bounding box in the area in which the bounding boxes are disposed.

At this time, the 3D printing apparatus can arrange the 3D mesh in consideration of the angle at which the bounding box is rotated in the previous steps. For example, when the bounding box is rotated by the first rotation angle, the 3D printing apparatus may rotate the 3D mesh corresponding to the bounding box by rotating the first direction by a first rotation angle. In addition, for example, when the bounding box is rotated by the second rotation angle, the 3D printing apparatus can rotate the 3D mesh corresponding to the bounding box by the second rotation angle.

In step 111, the 3D printing device may perform 3D printing using a plurality of 3D meshes placed in the printing space. Thereby, a plurality of 3D objects can be printed at the same time.

Embodiments of the invention may be embodied in a computer system, for example, a computer-readable recording medium. 7, the computer system 700 may include one or more processors 710, a memory 720, a storage 730, a user interface input 740, and a user interface output 750, Elements, which may communicate with each other via bus 760. [ In addition, the computer system 700 may also include a network interface 770 for connecting to a network. The processor 710 may be a CPU or a semiconductor device that executes processing instructions stored in the memory 720 and / or the storage 730. Memory 720 and storage 730 may include various types of volatile / non-volatile storage media. For example, the memory may include a ROM 724 and a RAM 725.

Accordingly, embodiments of the invention may be embodied in a computer-implemented method or in a non-volatile computer storage medium having stored thereon computer-executable instructions. The instructions, when executed by a processor, may perform the method according to at least one embodiment of the present invention.

Claims (16)

Determining a bounding box of each of the plurality of 3D meshes;
Rotating one of the bounding boxes inclined at one side of the bounding box so that one side of the bounding box is parallel to the reference line;
Placing in a printing space such that bounding boxes parallel to one side of the baseline do not overlap each other;
Placing a 3D mesh corresponding to each bounding box in an area in which a bounding box corresponding to the 3D mesh is disposed; And
Printing a plurality of 3D objects using the arranged 3D meshes
≪ / RTI >
2. The method of claim 1, wherein determining the bounding box comprises:
Calculating a convex hull of the 3D mesh; And
Determining a minimum bounding box surrounding the convex shell
≪ / RTI >
The method of claim 1, wherein arranging the bounding boxes comprises:
Determining a placement order of the bounding boxes based on at least one of a length and an area of sides of the bounding boxes;
3D printing method.
The method of claim 1, wherein arranging the bounding boxes comprises:
Determining placement candidate regions of the N-th bounding box based on the edges of the first to (N-1) -th bounding boxes;
Calculating an area of a rectangle surrounding all N bounding boxes when an N-th bounding box is arranged in the placement candidate region for each of the placement candidate regions; And
Placing an Nth bounding box in a placement candidate region where the area of the rectangle is calculated to be a minimum,
≪ / RTI >
5. The method of claim 4, wherein calculating the area of the rectangle comprises:
Calculating an area of the rectangle while rotating the N-th bounding box by 90 degrees
≪ / RTI >
The method according to claim 1,
Wherein the printing space is rectangular and the baseline is parallel to one side of the printing space
3D printing method.
The method according to claim 1,
Adjusting the size of the bounding box considering the interval between the 3D meshes
Further comprising the steps of:
The method of claim 1, wherein the step of disposing the 3D mesh comprises:
Placing the corresponding 3D mesh in consideration of the rotated angle of the bounding box corresponding to the 3D mesh;
≪ / RTI >
A 3D printing apparatus comprising a processor and a memory,
Wherein instructions for performing 3D printing using a plurality of 3D meshes and the plurality of 3D meshes are stored in the memory,
Wherein the instructions, when executed by the processor, cause the processor to:
Determining a bounding box of each of the plurality of 3D meshes, rotating one of the bounding boxes inclined at one side of the bounding box so that one side of the bounding box is parallel to the reference line, Placing the 3D mesh corresponding to each bounding box in an area where a bounding box corresponding to the corresponding 3D mesh is disposed and arranging a plurality of 3D objects on the 3D mesh using the arranged 3D meshes, That contain instructions to
3D printing device.
10. The method of claim 9,
Calculating a convex hull of the 3D mesh, and determining the bounding box of the minimum area surrounding the convex hull
3D printing device.
10. The method of claim 9,
Determining a placement order of the bounding boxes based on at least one of a length and an area of sides of the bounding boxes;
3D printing device.
10. The method of claim 9,
If the arrangement candidate regions of the N-th bounding box are determined based on the edges of the first to (N-1) -th bounding boxes and the N-th bounding box is arranged in the placement candidate region for each of the placement candidate regions, N Calculating an area of a rectangle all surrounding the bounding boxes, and placing an N-th bounding box in the placement candidate area where the area of the rectangle is calculated to be the smallest
3D printing device.
13. The computer-readable medium of claim 12,
And calculating the area of the rectangle while rotating the N-th bounding box by 90 degrees
3D printing device.
10. The method of claim 9,
Wherein the printing space is rectangular and the baseline is parallel to one side of the printing space
3D printing device.
10. The method of claim 9,
And adjusting the size of the bounding box in consideration of the interval between the 3D meshes
3D printing device.
10. The method of claim 9,
And arranging the 3D mesh in consideration of the angle of rotation of the bounding box corresponding to the 3D mesh when the 3D mesh is arranged
3D printing device.

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