JP7580688B2 - Method for creating 3D shape data for a solid model, method for manufacturing a solid model, and method for manufacturing a solid model - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act October 16-18, 2019, Manufacturing Fair 2019 January 16, 2020, http://3dcreators. jp/column/ms_25. shtml April 9, 2020, www. hotaru3d. com/SHOP/CS_YMDK_001_100. html, www. hotaru3d. com/SHOP/CS_YMDK_002_100. html

The present invention relates to a method for creating three-dimensional shape data for a three-dimensional model, a method for manufacturing a three-dimensional model, and a three-dimensional model.

Museums and other places exhibit skeletal specimens of huge creatures such as sperm whales and African elephants, academically valuable creatures called "living fossils" such as coelacanths, and extinct creatures such as dinosaurs. However, the specimens exhibited in museums and other places only have skeletons, and it is difficult to understand the relative positions of the skeleton and the shell even when comparing them with the drawings of the shell. In particular, sperm whales have an organ called cerebrospinal fluid in their heads and almost no bones, so the difference between the skeleton and the shell is large. In addition, proboscideans such as African elephants have no bones in their noses, so the skeleton and the shell are very different. As such, skeletal specimens are not ideal for research or study because there is little information that can be obtained by themselves. Furthermore, with conventional skeletal specimens, screw holes must be drilled to assemble the skeleton, and caulking must be used to connect unconnected bones, damaging valuable materials. In addition, large skeletal specimens cannot be handled for research or study, so people must move around while observing them. Even if replicas are made, they need to be molded, which is expensive and there is a risk of the bones being damaged, so they cannot be mass-produced.

For small animals that are difficult to dissect, "transparent skeletal specimens" made by staining the actual living organism are widely used in research fields such as taxonomy, comparative anatomy, and embryology. However, toxic chemicals are required to process the living organism, and from a safety standpoint they cannot be used as educational materials for children. In addition, they must be observed in a case, so they cannot be handled, and as they use actual living organisms, they cannot be reproduced, and they cannot be made for larger organisms.

Human body models for medical and educational purposes are created using 3D printers. For example, Patent Document 1 discloses a 3D model creation method in which 3D shape data is created for biological parts and their internal structure parts, the model material used for modeling is defined for each biological part and internal structure part, and modeling is performed using a 3D printer using the defined material based on the 3D shape data for the biological part and its internal structure part. However, this method uses data obtained by medical diagnostic equipment, and cannot create models of large organisms for which medical diagnostic equipment cannot be used.

In recent years, there has been an increasing need for models that reproduce the detailed skeletons and shells of dinosaurs and large creatures (whales, elephants, etc.) for research and educational purposes. However, unlike human models that can be made with a 3D printer using CT scan image data, accurate 3D data cannot be created for extinct dinosaurs or large creatures for which CT scans or 3D scanners cannot be used. In addition, there is a problem that 3D scanners cannot be used for small aquatic creatures because their shells cannot be preserved on land.

Patent No. 5239037 specification

The present invention has been made in consideration of the above-mentioned problems with the conventional technology, and aims to provide a method for creating 3D shape data for a 3D model, a method for manufacturing a 3D model, and a 3D model that can create 3D shape data for a 3D model of a structure from 3D data on the internal structure and 2D data on the appearance of the external structure without using a medical diagnostic device, 3D scanner, etc.

In order to solve the above problems, a method for creating three-dimensional shape data for a three-dimensional model according to a first aspect of the present invention comprises the steps of:
A method for creating three-dimensional shape data for a three-dimensional model, for manufacturing a three-dimensional model of a structure having an internal structure and an external structure formed by combining a plurality of internal parts, using a three-dimensional data creation device, comprising the steps of:
a first step of combining three-dimensional shape data of the plurality of internal parts of the internal structure to generate internal three-dimensional shape data of the internal structure;
A second step of creating an external two-dimensional estimated cross-sectional view of the external structure based on the appearance information of the external structure;
a third step of creating an external two-dimensional cross-sectional view by aligning the external two-dimensional estimated cross-sectional view with the internal three-dimensional shape data based on a relative positional relationship between internal feature points on the internal three-dimensional shape data and external feature points on the external two-dimensional estimated cross-sectional view corresponding to the internal feature points;
a fourth step of generating external three-dimensional shape data from the plurality of external two-dimensional cross-sectional views;
a fifth step of combining the internal three-dimensional shape data and the external three-dimensional shape data to generate three-dimensional shape data;
The present invention is characterized by comprising:

In the method for creating three-dimensional shape data for a three-dimensional model of the first invention, the internal structure is a combination of multiple internal parts inside the structure. The three-dimensional shape data of the internal structure can be created by combining the three-dimensional shape data of each actual part obtained using a medical diagnostic device, a 3D scanner, or the like. The external structure is the external form that covers the internal structure. The external two-dimensional estimated cross-sectional view of the external structure can be created based on appearance information consisting of appearance data or two-dimensional images such as restored images, imagined images, photographs, and video captures. The external two-dimensional estimated cross-sectional view of the external structure is not based on three-dimensional shape data of the actual external form that covers the actual internal structure, so it does not match the three-dimensional shape data of the internal structure. Therefore, the external two-dimensional estimated cross-sectional view is aligned with the internal three-dimensional shape data based on the relative positional relationship between the internal feature points on the internal three-dimensional shape data and the external feature points on the external two-dimensional estimated cross-sectional view that correspond to the internal feature points, to create the external two-dimensional cross-sectional view. As a result, the external two-dimensional cross-sectional view is matched with the internal three-dimensional shape data.

The third step is
a: selecting an internal feature point A on the internal three-dimensional shape data;
b: A distance L1 from the internal feature point A to the outline of the external structure is identified, and a point that is a distance L1 away from the internal feature point A is set as an estimated external feature point B;
c: selecting an external feature point C on the contour line of the estimated two-dimensional cross-sectional view that corresponds to the internal feature point A;
d: A distance L2 from the external feature point C to the outer shape of the internal structure is identified, and a point that is a distance L2 away from the external feature point C is set as an estimated internal feature point D;
e: superimposing the estimated external feature point B and the external feature point C, and adjusting the scale of the two-dimensional estimated cross-sectional view so that the estimated internal feature point D coincides with the internal feature point A;
f: setting a contour effective range around the external feature point C, and deleting the contour of the external two-dimensional cross-sectional view excluding the contour effective range;
g: Steps a-f are performed on other internal feature points A;
h: Connecting the contours of the external two-dimensional estimated cross-sections of the contour effective ranges of adjacent external feature points C to generate an external two-dimensional cross-section;
i. Preferably, steps a to h are performed on other external two-dimensional estimated cross-sectional views to generate a plurality of external two-dimensional cross-sectional views.

The fourth step is
a plurality of external three-dimensional shape data components are created by extruding and overlapping the plurality of external two-dimensional cross-sectional views;
combining the plurality of external three-dimensional shape data components;
It is preferable to generate external three-dimensional shape data by supplementing missing parts between the plurality of external three-dimensional shape data parts.

The method for producing a three-dimensional model according to the second aspect of the present invention comprises the steps of:
A method for manufacturing a three-dimensional model of a structure having an internal structure and an external structure, the method comprising the steps of:
a step of combining the internal three-dimensional shape data and the external three-dimensional shape data by the method of creating three-dimensional shape data for a solid model according to the first invention, thereby creating three-dimensional shape data;
and forming a three-dimensional model based on the three-dimensional shape data.
The internal space surrounded by the internal three-dimensional shape data is modeled using opaque resin,
A space between the contour of the internal three-dimensional shape data and the contour of the external three-dimensional shape data is formed from a transparent resin.

In the manufacturing method of a three-dimensional model of the second invention, the internal space surrounded by the internal three-dimensional shape data is modeled with opaque resin, and the space between the outline of the internal three-dimensional shape data and the outline of the external three-dimensional shape data is modeled with transparent resin, so that the internal structure modeled with opaque resin can be observed through the transparent resin between the external and internal structures modeled with transparent resin, making it possible to manufacture an elaborate three-dimensional model that allows the relative positional relationship between the external and internal structures to be understood.

It is preferable that the space between the outline of the internal 3D shape data of one of the adjacent internal parts of the internal structure and the outline of the internal 3D shape data of the other of the adjacent internal parts is molded from a transparent resin.

It is preferable to create offset 3D shape data at a position where the external 3D shape data is offset inward, to model an offset outer shape indicated by the offset 3D shape data using colored transparent resin, and to model an area between the offset outer shape of the offset 3D shape data and the outer shape of the external 3D shape data using transparent resin.
Alternatively, it is preferable to create offset 3D shape data at a position offset outward from the external 3D shape data, model the outer shape indicated by the external 3D shape data using colored transparent resin, and model the area between the outer shape of the external 3D shape data and the offset outer shape of the offset 3D shape data using transparent resin.
By molding the offset outer shape inside the external three-dimensional shape data with colored transparent resin, or molding the inner side of the offset outer shape outside the external three-dimensional shape data with colored transparent resin, the colored transparent resin remains when the transparent resin on the outer surface is polished, and a three-dimensional model in which the external structure is colored translucently can be manufactured.

The three-dimensional model of the third invention is as follows:
A three-dimensional model of a structure having an internal structure and an external structure formed by combining a plurality of internal parts,
The internal space of the internal structure is formed from an opaque resin,
The space between the outer shape of the internal structure and the outer shape of the external structure is formed from a transparent resin.

In the three-dimensional model of the third invention, the internal space of the internal structure is molded from opaque resin, and the space between the external form of the internal structure and the external form of the external structure is molded from transparent resin, so that the internal structure molded from opaque resin can be observed through the transparent resin between the external and internal structures, and the relative positions of the external and internal structures can be understood.

It is preferable that the space between the outer contours of one of the adjacent internal parts of the internal structure is made of a transparent resin. By making the space between the internal parts out of a transparent resin, it is possible to grasp the relative positions and connection state between the internal parts.

The transparent resin preferably has elasticity.
Because the transparent resin between the external and internal structures has elasticity, when the external structure is moved, the internal structure moves in response, making it possible to grasp the relative relationship between the external and internal structures.

It is preferable that a colored transparent resin layer is formed on the inside of the outer surface of the external structure, and the space between the colored transparent resin layer and the outer surface of the external structure is formed with a transparent resin.
Since a colored transparent resin layer is formed on the inside of the outer surface of the external structure, the color of the colored transparent resin layer does not fade even when the transparent resin on the surface is polished, and the external structure becomes a three-dimensional model that is colored semi-transparently.

According to the method for creating 3D shape data for a 3D model of the first invention, an external 2D cross-sectional view is created by aligning the external 2D estimated cross-sectional view with the internal 3D shape data based on the relative positional relationship between the internal feature points on the internal 3D shape data and the external feature points on the external 2D estimated cross-sectional view that correspond to the internal feature points. Therefore, even if the external 2D estimated cross-sectional view of the external structure is not based on 3D shape data of the actual external form that covers the actual internal structure, the external 3D shape data is consistent with the internal 3D shape data. This makes it possible to create 3D shape data for a 3D model of a structure for which medical diagnostic equipment, 3D scanners, etc. cannot be used.

According to the manufacturing method of the three-dimensional model of the second invention, the internal space surrounded by the internal three-dimensional shape data is modeled with opaque resin, and the space between the external shape of the internal three-dimensional shape data and the external shape of the external three-dimensional shape data is modeled with transparent resin, so that the internal structure modeled with opaque resin can be observed through the transparent resin between the external structure and the internal structure modeled with transparent resin, and an elaborate three-dimensional model can be manufactured that allows the relative positional relationship between the external structure and the internal structure to be understood.

According to the three-dimensional model of the third invention, the internal space of the internal structure is molded from opaque resin, and the space between the external form of the internal structure and the external form of the external structure is molded from transparent resin, so that the internal structure molded from opaque resin can be observed through the transparent resin between the external and internal structures molded from transparent resin, and the relative positional relationship between the external and internal structures can be grasped. In addition, because the space between the internal parts is molded from transparent resin, the relative positions and connection state between the internal parts can be grasped.

FIG. 2 is a flowchart showing a method for creating three-dimensional shape data for a solid model according to the present invention. FIG. 2 is a diagram showing a flow of aligning an external two-dimensional estimated cross-sectional view in step 103 of FIG. 1 . FIG. 2 is a diagram showing a flow of creating external three-dimensional shape data in step 104 of FIG. 1 . An oblique view of a sperm whale skeleton represented by internal 3D shape data. An image showing what a sperm whale looks like. External 2D estimated XZ cross section (a) and external 2D estimated YZ cross section (b) along the sperm whale spinal cord. A diagram showing internal feature points A and estimated external feature points B of a skeleton. A diagram showing external feature points C and estimated internal feature points D of the outer shell. 13A to 13C are diagrams showing steps of adjusting the scale of the external 2D estimated cross-sectional view of the outer shell. FIG. 11 is an external 2D estimated cross-sectional view showing the contour valid range around multiple external feature points C. External 2D estimated XZ cross section (a) and external 2D estimated XY cross section (b) of a sperm whale superimposed on the skeleton. Multiple external 2D estimated YZ cross sections of a sperm whale superimposed on the skeleton. 1A is an external two-dimensional estimated XZ cross-sectional view, and FIG. 1B is a perspective view showing a solid body obtained by extruding the external two-dimensional estimated XZ cross-sectional view on both sides in the Y direction. 1A is an external two-dimensional estimated YZ cross-sectional view, and FIG. 1B is a perspective view showing a solid body obtained by extruding the external two-dimensional estimated YZ cross-sectional view on both sides in the X direction. 13A and 13B are a side view and a perspective view showing a state in which a solid body obtained by extruding an external two-dimensional estimated XZ cross section and a solid body obtained by extruding an external two-dimensional estimated YZ cross section are superimposed on each other. FIG. 13 is a perspective view showing an external three-dimensional shape data temporary part and a skeleton. FIG. 13 is a perspective view showing a combination and skeleton of a plurality of temporary parts based on external three-dimensional shape data. 1A is an external two-dimensional estimated XY cross-sectional view, and FIG. 1B is a perspective view showing a solid body obtained by extruding the external two-dimensional estimated XY cross-sectional view on both sides in the Z direction. 13 is a perspective view showing a state in which a solid body obtained by extruding the external two-dimensional estimated XY cross-sectional view is superimposed on a plurality of external three-dimensional shape data temporary parts. FIG. FIG. 13 is a perspective view showing a combination and skeleton of a plurality of external three-dimensional shape data components. 1A is a perspective view showing an inscribed line of an end face of an external three-dimensional shape data component, and FIG. 1B is a perspective view showing a state in which a missing portion of the external three-dimensional shape data component has been completed. A side view of a sperm whale's outer shell represented by external 3D shape data. A side view of the sperm whale's shell and skeleton, shown in external 3D shape data. An enlarged partial view of a sperm whale showing 3D shape data in OBJ format. FIG. 2 is a diagram showing a three-dimensional shape data creating device and a three-dimensional modeling device. FIG. 4 is a diagram showing a flow of a method for manufacturing a three-dimensional model according to the present invention. FIG. 13 is a diagram showing the state of modeling by a three-dimensional printer. FIG. 13 is an enlarged cross-sectional view showing the state of modeling by a three-dimensional printer. FIG. 13 is a cross-sectional view represented by external three-dimensional shape data, showing the state in which the outer shell is offset in order to color the surface of the outer shell. A photo of a three-dimensional model of a sperm whale created using a 3D printer. An enlarged cross-sectional view of a part of a three-dimensional model of a sperm whale created using a 3D printer.

An embodiment of the present invention will be described below with reference to the attached drawings.

<Embodiment of a method for creating three-dimensional shape data for a solid model>
FIG. 1 shows a flow of a method for creating three-dimensional shape data for a three-dimensional model, for manufacturing a three-dimensional model of a structure having an internal structure and an external structure formed by combining a plurality of internal parts, using a three-dimensional data creation device.

The three-dimensional data creation device consists of a computer that uses software such as three-dimensional computer graphics (3DCG) and three-dimensional computer-aided design (3DCAD) to create three-dimensional shape data for a solid model that can be printed using a 3D printer.

The three-dimensional model that is the subject of this invention is a three-dimensional model of a structure that has an internal structure made up of multiple internal parts and an external structure. For example, in the case of a three-dimensional model of a large animal such as a sperm whale, the internal structure is a skeleton made up of multiple bones, and the external structure is the shell that covers the skeleton. Depending on the purpose of the three-dimensional model, the internal structure may include internal organs such as the brain and heart in addition to the skeleton.

In step 101, internal three-dimensional shape data of the internal structure is created. The internal three-dimensional shape data of the internal structure can be created by combining, on 3DCG or 3D CAD, three-dimensional shape data of each actual part obtained using a medical diagnostic device or a 3D scanner. On 3DCG or 3D CAD, the dimensions of the three-dimensional shape data are adjusted to the actual dimensions of the internal structure. Even for large animals such as sperm whales, the bones of the skeleton of the internal structure are small, so accurate three-dimensional shape data of each bone can be obtained by scanning each bone of a skeletal specimen exhibited in a museum or the like with a 3D scanner. In addition, if three-dimensional shape data of the skeleton is available from a museum or the like, it can be used. The three-dimensional shape data of each bone is combined on 3DCG or 3D CAD to create internal three-dimensional shape data of the skeleton.

When 3D shape data is only available for a portion of the skeleton, 3D shape data for the missing bone is created from 2D images on 3DCG or 3D CAD. When 2D image data is only available in part, 2D images of the nonexistent bones are created, and internal 3D shape data for the skeleton is created from these 2D image data on 3DCG or 3D CAD. Figure 4 shows skeleton 1, which is the internal structure of a sperm whale, represented by the internal 3D shape data that has been created.

In step 102, an external 2D estimated cross-sectional view of the external structure is created based on the appearance information of the structure. The appearance information can be appearance data such as body length and waist circumference, or 2D images such as restored images, imagined drawings, pictures, photographs, and video captures. Based on this appearance information, the contours of multiple cross sections are extracted and an external 2D estimated cross-sectional view is created. The direction of the external 2D estimated cross-sectional view is based on the directions of the X, Y, and Z axes shown in Figure 4. For example, based on image 2 of a sperm whale in Figure 5, multiple external 2D estimated XZ cross-sectional views along the spinal cord in Figure 6(a) and external 2D estimated YZ cross-sectional views such as those in Figure 6(b) are created.

In step 103, the external 2D estimated cross-sectional view is aligned with the internal 3D shape data. The external 2D estimated cross-sectional view is not based on the 3D shape data of the actual shell that covers the existing internal structure, and therefore does not match the 3D shape data of the internal structure. Therefore, the external 2D estimated cross-sectional view is aligned based on the relative positional relationship between the internal feature points on the internal 3D shape data and the external feature points on the external 2D estimated cross-sectional view that correspond to the internal feature points, to create an external 2D cross-sectional view. The external 2D cross-sectional view obtained by this alignment is aligned with the internal 3D shape data.

Specifically, in step 103a in Fig. 2, internal feature point A on the internal 3D shape data is selected. As shown in Fig. 7, in the case of a sperm whale, the lumbar vertebrae, the tip of the caudal vertebra, the skull, the tip of the maxilla, the tip of the mandible, the mandibular joint, the eyes, the ribs, the joints at the base of the pectoral fins, the tips of the phalanges of the pectoral fins, etc., of the skeleton 1 can be selected as internal feature point A.

In step 103b, the distance L1 from the internal feature point A on the internal 3D shape data to the contour of the external structure is identified, and the point that is the distance L1 away from the internal feature point A is set as the estimated external feature point B. In the case of a sperm whale, the thickness of the skin and fat obtained from literature, etc. can be used as a reference for the distance L1 from the internal feature point A to the contour of the external structure.

In step 103c, as shown in FIG. 8, an external feature point C on the contour line of the 2D estimated cross-sectional view that corresponds to the internal feature point A is selected.

In step 103d, the distance L2 from the external feature point C to the outline of the internal structure is identified, and the point that is the distance L2 away from the external feature point C is set as the estimated internal feature point D. In the case of a sperm whale, the thickness of the skin and fat obtained from literature, etc. can be used as a reference for determining the distance L2 from the external feature point C to the outline of the internal structure.

In step 103e, as shown in FIG. 9, the estimated external feature point B and the external feature point C are superimposed, and the aspect ratio is fixed and the scale of the estimated external 2D cross-sectional view is adjusted so that the estimated internal feature point D coincides with the internal feature point A.

In step 103f, as shown in FIG. 10, a contour effective range W around the external feature point C is set, and the contour of the external 2D estimated cross-sectional view excluding the contour effective range is deleted. The contour effective range W is adjusted according to the shape around the external feature point C. For example, it is set to be short if the shape around the external feature point C is complex, and long if it is monotonous. In the embodiment of FIG. 10, the contour effective range W around the external feature point C is set to be long because the part in front of the external feature point C has a relatively gentle and monotonous shape, and is set to be short because the part after it is more complex than the part before it.

In step 103g, steps 103a-f are performed on the other internal feature points A.

In step 103h, the contours of the external 2D estimated cross-sections of the contour valid ranges of adjacent external feature points C are connected to create an external 2D cross-section as shown in FIG. 11.

In step 103i, steps 103a-h are performed on the other external 2D estimated cross-sections to create multiple external 2D cross-sections. In the case of a sperm whale, it is preferable to create multiple external 2D cross-sections, such as an external 2D XZ cross-section and an external 2D XY cross-section in the spine direction shown in Figures 11(a) and (b), and multiple external 2D YZ cross-sections in the left-right longitudinal sections shown in Figures 12(a) and (b).

In step 104, external 3D shape data is created based on the external 2D cross-sectional view created in step 103.

Specifically, in step 104a of FIG. 3, the external two-dimensional XZ cross-sectional view is extruded in the Y direction to form a solid, as shown in FIG. 13. It is preferable to extrude on both sides in the Y direction so that the internal structure is included inside, as shown in FIG. 13(b).

In step 104b, the external two-dimensional YZ cross section is extruded in the X direction to form a solid, as shown in Figure 14. It is preferable to extrude on both sides in the X direction so that the extrusion is the same as the effective range of the contour, as shown in Figure 14(b).

In step 104c, as shown in FIG. 15, a solid obtained by extruding the external two-dimensional XZ cross-sectional view in the Y direction is superimposed on a solid obtained by extruding the external two-dimensional YZ cross-sectional view in the X direction, and the intersecting portion of the two solids is extracted to create a temporary external three-dimensional shape data part 3' as shown in FIG. 16.

In step 104d, if there are other external 2D YZ cross-sectional views, steps 104b to 104c are repeated to create external 3D shape data temporary part 3'.

In step 104e, multiple external 3D shape data temporary parts 3' are combined, as shown in FIG. 17.

In step 104f, the external two-dimensional XY cross-sectional view is extruded in the Z direction to form a solid, as shown in Figure 18. It is preferable to extrude on both sides in the Z direction so that the internal structure is included inside, as shown in Figure 18(b).

In step 104g, as shown in FIG. 19, a solid obtained by extruding the external 2D XY cross-sectional view in the Z direction is overlaid with the external 3D shape data temporary part 3', and the intersecting part of the two solids is extracted to create the external 3D shape data part 3 as shown in FIG. 20.

In step 104h, the missing parts of the space between the combined external 3D shape data components 3 are complemented and combined to create external 3D shape data. As shown in FIG. 21(a), the end faces in the X direction of the external 3D shape data components have cut-out parts 9 that were created during the overlapping operation. The inscribed lines 10 that contact the cut-out parts 9 and other parts on the corresponding end faces of the adjoining external 3D shape data components 3 are extracted, and are complemented with complementary parts 3a consisting of curved surfaces that follow the cut-out parts 9, as shown in FIG. 21(b).

In step 104i, the external 3D shape data that has been supplemented with the missing parts of the external 3D shape data component 3 is smoothed to form a continuous, smooth surface. This results in external 3D shape data that is consistent with the internal 3D shape data. Figure 22 shows the hull 4, which is an external structure of a sperm whale, represented by the created external 3D shape data.

After the external three-dimensional shape data is created, in step 105 of FIG. 1, three-dimensional shape data is created by combining the internal three-dimensional shape data and the external three-dimensional shape data. FIG. 23 shows the skeleton 1 and shell 4 of a sperm whale represented by the internal three-dimensional shape data and the external three-dimensional shape data. FIG. 24 is an enlarged view showing a portion of the three-dimensional shape data.

In step 106, the three-dimensional shape data is reduced to model size to create model-sized three-dimensional shape data.

As a result, even if the external 2D estimated cross-sectional view of the external structure is not based on 3D shape data of the actual shell that covers the actual internal structure, the external 3D shape data is consistent with the internal 3D shape data. This makes it possible to create 3D shape data for a solid model of a structure that cannot be created using medical diagnostic equipment or 3D scanners.

<Embodiment of Manufacturing Method for Three-Dimensional Model>
FIG. 25 shows a three-dimensional data creation device 11 and a three-dimensional modeling device 12 for implementing an embodiment of the method for manufacturing a three-dimensional model of the present invention.

As mentioned above, the three-dimensional data creation device 11 is a computer that uses software such as three-dimensional computer graphics (3DCG) and three-dimensional design support (3DCAD) to create three-dimensional shape data for a solid model that can be created by the three-dimensional modeling device 12, and is composed of a main body 13, a monitor 14, a keyboard 15, a mouse 16, etc.

The three-dimensional modeling device 12 is a 3D printer that models by layering resin or metal. The 3D printer can use various methods such as material extrusion, material jetting, powder bed fusion, binder jetting, liquid vat photopolymerization, sheet lamination, and directed energy volumetric modeling, but the material jetting method is more common and preferable. Figure 25 shows a 3D printer using the material extrusion method, and includes an X-axis unit 18 that moves the printer head 17 back and forth in the X-axis direction, a Z-axis unit 19 that moves the X-axis unit 18 back and forth in the Z-axis direction, a modeling stage 20 that can move back and forth in the Y direction, a cartridge 22 of acrylic resin 21, an extruder 23 that supplies the acrylic resin 21 to the printer head 17, and a control unit 24. The control unit 24 is connected to the main body 13 of the 3D data creation device 11 via LAN, receives 3D shape data in OBJ format from the 3D data creation device 11, slices it into layers, converts it into G-code data, and controls the X-axis unit 18, Z-axis unit 19, modeling stage 20, and extruder 23.

Figure 26 shows a modeling flow for implementing an embodiment of the manufacturing method for a three-dimensional model of the present invention. In step 201, three-dimensional shape data consisting of internal three-dimensional shape data and external three-dimensional shape data is created by the three-dimensional shape data creation method described above using the three-dimensional data creation device 11. This three-dimensional shape data is sent to the three-dimensional modeling device 12 in OBJ format.

In step 202, a three-dimensional model is created by the three-dimensional modeling device 12. As shown in FIG. 27, when the three-dimensional model 5 is a sperm whale, it is preferable to set the direction of the sperm whale's spine as the X-axis, the left-right direction as the Y-axis, and the up-down direction as the Z-axis in order to shorten the creation time.

In the modeling by the three-dimensional modeling device 12, as shown in FIG. 28, the internal space surrounded by the internal three-dimensional shape data is modeled with opaque resin 6, and the space between the external shape of the internal three-dimensional shape data and the external three-dimensional shape data is modeled with transparent resin 7. As the opaque resin 6, a colored acrylic resin is preferable, but it is not limited to this, and ABS resin, PLA resin, epoxy resin, nylon resin, rubber, silicon, polycarbonate (PC), polypropylene (PP), etc. can be used. As the transparent resin 7, an uncolored acrylic resin is preferable, but it is not limited to this, and ABS resin, PLA resin, epoxy resin, nylon resin, rubber, silicon, polycarbonate (PC), polypropylene (PP), etc. can be used. In addition, the space between the external shape of one internal three-dimensional shape data of adjacent internal parts of the internal structure and the external shape of the other internal three-dimensional shape data, for example, the space between the bones constituting the skeleton 1 in the case of a sperm whale, is modeled with transparent resin 7.

After being modeled by the three-dimensional modeling device 12, the transparent resin 7 is irradiated with ultraviolet light. This increases the transparency of the transparent resin 7.

After the modeling is performed by the three-dimensional modeling device 12, the outer surface of the three-dimensional model 5 is polished in step 203. This makes it possible to remove surface roughness and unevenness between layers of the three-dimensional model 5 that appear during modeling, and to make the surface smooth.

During modeling using the 3D modeling device 12, the outer surface of the 3D model 5 can be colored, but to prevent the color from fading due to polishing, the coloring can be done in the following two ways.

As shown in FIG. 29(a), the first method involves creating offset 3D shape data at a position offset inward from the external 3D shape data, forming a colored transparent resin layer 8 of a predetermined thickness on the offset outer shape 4a indicated by the offset 3D shape data, and forming transparent resin 7 between the colored transparent resin layer 8 on the offset outer shape 4a of the offset 3D shape data and the outer shell 4 of the external 3D shape data.

As shown in FIG. 29(b), the second method involves creating offset 3D shape data at a position offset outward from the external 3D shape data, forming a colored transparent resin layer 8 of a predetermined thickness on the outer shell 4 indicated by the external 3D shape data, and forming transparent resin 7 between the colored transparent resin layer 8 on the outer shell 4 of the external 3D shape data and the offset outer shape 4b indicated by the offset 3D shape data.

In either method, the colored transparent resin 8 is present inside the transparent resin 7 on the exterior surface of the shaped three-dimensional model 5, so even if the transparent resin 7 on the exterior surface is polished, the colored transparent resin 8 inside does not fade.

<Embodiments of the Three-Dimensional Model>
FIG. 30 shows a three-dimensional model 5 of a sperm whale manufactured by the above-mentioned method for manufacturing a three-dimensional model of the present invention.

As shown in Figure 31, in this three-dimensional model 5, the internal space of the skeleton 1 is formed from opaque resin 6, and the space between the skeleton 1 and the outer shell 4 is formed from transparent resin 7. Therefore, the skeleton 1 formed from opaque resin 6 can be observed through the transparent resin 7 between the skeleton 1 and the outer shell 4, and the relative positions of the skeleton 1 and the outer shell 4 can be understood. For example, in the case of a sperm whale, it can be confirmed that the head contains an organ called cerebral oil and has almost no bones. In addition, the condition of the jaw and unconnected bones such as pelvic vestiges can be clearly observed from any direction by holding the model 5.

The space between the contours of one bone 1a and the other bone 1b of the skeleton 1 is made of transparent resin 6, so the relative positions and connection state of the adjacent bones 1a and 1b can be grasped.

The transparent resin 7 that forms the space between the external 3D shape data and the internal 3D shape data is preferably elastic. Since the transparent resin 7 between the outer shell 4 and the skeleton 1 has elasticity, when the outer shell 4 is moved, the skeleton 1 moves accordingly, so that the relative relationship between the outer shell 4 and the skeleton 1 can be grasped.

It is preferable that a colored transparent resin layer 8 is formed on the inside of the outer surface of the external structure, and the space between the colored transparent resin layer 8 and the outer surface of the external structure is formed with transparent resin 7. By forming the colored transparent resin layer 8 on the inside of the outer surface of the external structure, the color of the colored transparent resin layer 8 does not fade even if the surface transparent resin 7 is polished, and the external structure becomes a three-dimensional model that is colored translucently.

The present invention is not limited to the above-described embodiment, and modifications and variations can be made within the scope of the present invention. For example, the external two-dimensional cross-sectional view is not limited to an XZ cross-section, an XY cross-section, or a YZ cross-section, and can be a cross-section in any direction.

In addition, the above embodiment describes a method for creating three-dimensional shape data for a three-dimensional model of an animal such as a sperm whale, a method for manufacturing a three-dimensional model, and a three-dimensional model, but the present invention can also be applied to three-dimensional models of buildings and structures.

Reference Signs List 1: skeleton 2: photograph 3: external three-dimensional shape data component 3': external three-dimensional shape data temporary component 3a: supplementary component 4: outer shell 4a: offset outer shape 4b: offset outer shape 5: three-dimensional model 6: opaque resin 7: transparent resin 8: colored transparent resin 9: cut-out portion 10: inscribed line 11: three-dimensional data creation device 12: three-dimensional modeling device

Claims (9)

A method for creating three-dimensional shape data for a three-dimensional model, for manufacturing a three-dimensional model of a structure having an internal structure and an external structure formed by combining a plurality of internal parts, using a three-dimensional data creation device, comprising the steps of:
a first step of combining three-dimensional shape data of the plurality of internal parts of the internal structure to generate internal three-dimensional shape data of the internal structure;
A second step of creating an estimated two-dimensional external cross-sectional view of the external structure based on the appearance information of the external structure;
a third step of creating an external two-dimensional cross-sectional view by aligning the external two-dimensional estimated cross-sectional view with the internal three-dimensional shape data based on a relative positional relationship between internal feature points on the internal three-dimensional shape data and external feature points on the external two-dimensional estimated cross-sectional view corresponding to the internal feature points;
a fourth step of generating external three-dimensional shape data from the plurality of external two-dimensional cross-sectional views;
a fifth step of combining the internal three-dimensional shape data and the external three-dimensional shape data to generate three-dimensional shape data;
A method for creating three-dimensional shape data for a solid model, comprising: The third step is
a: selecting an internal feature point A on the internal three-dimensional shape data;
b: A distance L1 from the internal feature point A to the outline of the external structure is identified, and a point that is a distance L1 away from the internal feature point A is set as an estimated external feature point B;
c: selecting an external feature point C on the contour line of the estimated two-dimensional cross-sectional view that corresponds to the internal feature point A;
d: A distance L2 from the external feature point C to the outer shape of the internal structure is identified, and a point that is a distance L2 away from the external feature point C is set as an estimated internal feature point D;
e: superimposing the estimated external feature point B and the external feature point C, and adjusting the scale of the two-dimensional estimated cross-sectional view so that the estimated internal feature point D coincides with the internal feature point A;
f: setting a contour effective range around the external feature point C, and deleting the contour of the external two-dimensional cross-sectional view excluding the contour effective range;
g: Steps a-f are performed on other internal feature points A;
h: Connecting the contours of the external two-dimensional estimated cross-sections of the contour effective ranges of adjacent external feature points C to generate an external two-dimensional cross-section;
2. The method for creating three-dimensional shape data for a three-dimensional model according to claim 1, further comprising the steps of: i) performing steps a to h on other exterior two-dimensional estimated cross-sectional views to create a plurality of exterior two-dimensional cross-sectional views. The fourth step is
a plurality of external three-dimensional shape data components are created by extruding and overlapping the plurality of external two-dimensional cross-sectional views;
combining the plurality of external three-dimensional shape data components;
3. The method for creating three-dimensional shape data for a solid model according to claim 1, wherein the external three-dimensional shape data is created by complementing missing parts between the plurality of external three-dimensional shape data components. A method for manufacturing a three-dimensional model of a structure having an internal structure and an external structure, the method comprising the steps of:
a step of generating three-dimensional shape data by combining the internal three-dimensional shape data and the external three-dimensional shape data by the method for generating three-dimensional shape data for a solid model according to any one of claims 1 to 3;
and forming a three-dimensional model based on the three-dimensional shape data.
The internal space surrounded by the internal three-dimensional shape data is modeled using opaque resin,
A method for manufacturing a three-dimensional model, comprising the steps of: forming a space between an outline of the internal three-dimensional shape data and an outline of the external three-dimensional shape data with a transparent resin. The method for manufacturing a three-dimensional model according to claim 4, characterized in that the space between the contour of the internal three-dimensional shape data of one of the adjacent internal parts of the internal structure and the contour of the internal three-dimensional shape data of the other of the adjacent internal parts is molded with transparent resin. The method for manufacturing a three-dimensional model according to claim 4 or 5, characterized in that offset three-dimensional shape data is created at a position where the external three-dimensional shape data is offset inward, the offset outer shape indicated by the offset three-dimensional shape data is modeled with colored transparent resin, and the area between the offset outer shape of the offset three-dimensional shape data and the outer shape of the external three-dimensional shape data is modeled with transparent resin. The method for manufacturing a three-dimensional model according to claim 4 or 5, characterized in that offset three-dimensional shape data is created at a position where the external three-dimensional shape data is offset outward, the external shape indicated by the external three-dimensional shape data is modeled with colored transparent resin, and the area between the external shape of the external three-dimensional shape data and the offset external shape of the offset three-dimensional shape data is modeled with transparent resin. A three-dimensional model of a structure having an internal structure and an external structure formed by combining a plurality of internal parts,
The internal space of the internal structure is formed from an opaque resin,
A space between the outer shape of the inner structure and the outer shape of the outer structure is formed of a transparent resin,
A three-dimensional model, characterized in that an offset outline is formed inside the outer surface of the external structure at a position where the external three-dimensional shape data of the external structure is offset, a colored transparent resin layer is formed on the outer surface of the offset outline, and a space between the colored transparent resin layer and the outer surface of the external structure is molded with transparent resin. A three-dimensional model of a structure having an internal structure and an external structure formed by combining a plurality of internal parts,
The internal space of the internal structure is formed from an opaque resin,
A space between the outer shape of the inner structure and the outer shape of the outer structure is formed of a transparent resin,
A three-dimensional model, characterized in that an offset contour is formed outside the outer surface of the external structure at a position where the external three-dimensional shape data of the external structure is offset, a colored transparent resin layer is formed on the outer surface of the external structure, and a space between the colored transparent resin layer and the offset contour is formed with transparent resin.

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