JP2012003520A - Three-dimensional printed matter production support device, plug-in program, three-dimensional printed matter production method, and three-dimensional printed matter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce three-dimensional printed matter within a practical time without photographing a real subject.SOLUTION: A control unit 11 of a three-dimensional printed matter production support device 10 generates a three-dimensional CG model 7 of an object Obj by a function of a modelling program 21 and stores it to a storage part 12. Then, according to a function of a rendering program 22, the control unit 11 calculates a shape and position of the three-dimensional CG model 7, lighted conditions (luster), and the like, generates a directivity image 6, and stores it to the storage part 12. A plug-in 23 is a program for defining a variety of setting values for generating the directivity image 6 in a ray-tracing function. Then, the control unit 11 generates one composed image 2 from a plurality of directivity images 6 by means of a function of an image composition program 24 and stores it to the storage part 12.

Description

  The present invention relates to a three-dimensional printed material production support apparatus that supports production of a three-dimensional printed material, a three-dimensional printed material production method, and a three-dimensional printed material.

Conventionally, stereoscopic techniques have been extensively studied and various techniques have been realized. As a method for realizing stereoscopic vision in a printed material that does not use an electrical device, for example, there is a method using a lenticular lens sheet.
The lenticular lens is a lens having a semi-cylindrical curved surface, and has a property that the focal position moves with respect to the incident direction of light. Using this property, stereoscopic images with the naked eye (stereoscopic images that do not require special glasses) can be obtained by placing images according to the left and right eyes at the focal position when the lenticular lens is viewed from the left and right eyes. Can be realized. Hereinafter, the printed material in which the stereoscopic view is realized is referred to as “stereoscopic printed material”.
When the lenticular lens sheet is used, striped images are arranged on the back of the lenticular lens sheet so that the left and right eyes can observe a pair of images according to the position of the face. Then, when the observer moves the position of his / her face (when the viewing direction is changed), the left and right eyes move at a constant interval, so that the observer can move the image following the movement of the face. You can see the change.

The present applicants have already established a method for creating a three-dimensional printed material that realizes multi-view autostereoscopic viewing using image data photographed by a dedicated photographing device (see Patent Documents 1 and 2). . Here, the multi-viewpoint means the above-described “change in the image following the movement of the face”.
In Patent Document 1, an image of an actual subject is photographed by a plurality of cameras (dedicated photographing devices) arranged horizontally, and the images to be printed on a three-dimensional printed matter are appropriately synthesized by combining the photographed images. The creation is described. Note that the number of images shot by a dedicated shooting device needs to be several hundred to several thousand.
Patent Document 2 discloses a halftone processing method specialized for three-dimensional printed matter. By the method described in Patent Document 2, it is possible to obtain a three-dimensional printed material with improved dot printing resolution and reduced image roughness. Conventionally, there was a problem of printing accuracy, and the viewpoint of about 2 to 7 was the limit, but if the method described in Patent Document 2 is used, the viewpoint of about 40 to 100, which is several tens of times that of the prior art, should be given. Can do.

JP 2007-147737 A JP 2009-186972 A

However, as described in Patent Document 1, in the case of a method of photographing an actual subject using a dedicated photographing device, the size of the subject that can be photographed is limited by the photographing space and the angle of view of the camera. In the first place, the actual subject was necessary, and the range of expression was narrow.
On the other hand, for example, there is a demand for expressing a large subject such as an entire automobile as a three-dimensional printed matter. In addition, for example, there is a demand for expressing a three-dimensional printed product without creating a mock-up (a model that looks like the real thing) for a company logo or a fictional character.

  The present invention has been made in view of the above-described problems, and its purpose is to produce a three-dimensional printed material that supports producing a three-dimensional printed material within a practical time without photographing a real subject. It is to provide a support device or the like.

In order to achieve the above-described object, a first invention is a three-dimensional printed material production support apparatus that supports the production of a three-dimensional printed material that realizes a stereoscopic view of a desired object. A setting means for setting the position (CP _n ) of the correct camera and the starting point (NP) and direction (NV) of the light ray incident on the projection plane (PS), and based on the values set by the setting means, Rendering means for creating an image of the object photographed by the camera by tracking the ray with respect to a CG model of the object, and the setting means is a lenticular lens used for the three-dimensional printed matter based on the focal length (f) and the three-dimensional print print resolution (dpi), and set the line-of-sight direction (theta _n) for directional images (DI _n) included in the three-dimensional printed matter Position of the camera on the basis of the sight line direction (theta _n) Set (CP _n), further, for each rendered pixel (RP), point distance from (VP) to said projection surface (PS) (fd) And a starting point (NP) and direction (NV) of the light beam based on the camera position (CP _n ).
According to the first invention, a three-dimensional printed material can be produced within a practical time without photographing an actual subject.

In the first invention, the setting means sets the horizontal coordinate of the start point (NP _c ) of the ray in the camera coordinate system as the horizontal coordinate (x _r ) of the rendering target pixel (RP), and sets the camera coordinate from the world coordinate system. By performing conversion to the system, the start point (NP) of the ray in the world coordinate system is calculated.
Further, the setting means according to the first invention is configured such that the camera is arranged in parallel, and x _n = the length of a perpendicular drawn from the camera to the projection plane PS (Z ₀ ) × tan θ _n , A horizontal coordinate (xn) of the camera position (CP _n ) is calculated.
Further, the setting means according to the first aspect of the invention is configured such that the line-of-sight direction (passing through the focal point of the lenticular lens L (m) of the three-dimensional printed material from the pixel in correspondence with the arrangement of the pixels on the printing surface of the three-dimensional printed material. θ _n ) is calculated.

According to a second aspect of the present invention, a computer is configured such that a virtual camera position (CP _n ) and a light ray incident point (NP) and direction (NV) incident on the projection plane (PS) with respect to the projection plane (PS). Based on the value set by the setting unit, the ray is traced with respect to the CG model of the desired object, thereby creating an image of the object photographed by the camera A plug-in program for a program for functioning as a rendering unit, wherein the setting unit is configured to print a focal length (f) of a lenticular lens used for a three-dimensional printed material for realizing a stereoscopic view of the desired object and the three-dimensional printed material. based on the resolution (dpi), and set the line-of-sight direction (theta _n) for directional images (DI _n) contained in the solid printed matter, the sight line direction Sets the position (CP _n) of the camera based on (theta _n), further, for each rendered pixel (RP), the viewpoint (VP) distance to the projection surface (PS) from (fd) and the camera This is a plug-in program characterized in that the starting point (NP) and direction (NV) of the light beam are set based on the position (CP _n ).
According to the second invention, a computer on which general-purpose CG software is installed can be caused to function as the three-dimensional printed material production support apparatus of the first invention.

A third invention is a three-dimensional printed material production method for producing a three-dimensional printed material that realizes a stereoscopic view of a desired object, wherein the computer models a CG model of the object, and the computer includes a projection plane (PS). ) For setting a virtual camera position (CP _n ) and a starting point (NP) and direction (NV) of a light ray incident on the projection plane (PS), and a computer Rendering an image of the object imaged by the camera by tracking the ray against the CG model based on the value set by the step, the setting step comprising: Based on the focal length (f) of the lenticular lens used in the 3D print and the print resolution (dpi) of the 3D print Set the directional images included in the stereoscopic prints (DI _n) line-of-sight direction (theta _n) for, set the position (CP _n) of the camera on the basis of the sight line direction (theta _n), further, it is rendered pixel For each (RP), based on the distance (fd) from the viewpoint (VP) to the projection plane (PS) and the position (CP _n ) of the camera, the starting point (NP) and direction (NV) of the light beam are set. This is a method for producing a three-dimensional printed product.
According to the third invention, it is possible to produce a three-dimensional printed matter within a practical time without photographing an actual subject.

According to a fourth aspect of the present invention, a printed material on which a synthesized image, which is an image obtained by synthesizing a large number of images corresponding to a desired object, is combined with a lenticular sheet, and a stereoscopic view of the object is realized. A three-dimensional printed material, in which a computer models a CG model of the object, and a virtual camera position (CP _n ) and a ray incident on the projection plane (PS) with respect to the projection plane (PS). A starting point (NP) and direction (NV) are set, and based on the set values, the ray is traced with respect to the CG model, thereby creating a directional image of the object photographed by the camera. Then, a composite image is created based on the directional image, and the printing apparatus prints the composite image on the printed matter, and the focal point of the lenticular lens used for the three-dimensional printed matter. Based on the release (f) and the three-dimensional print print resolution (dpi), the three-dimensional printed material to the viewing direction with respect to directional images (DI _n) contained (theta _n) is set, in the sight line direction (theta _n) Based on this, the camera position (CP _n ) is set, and for each rendering target pixel (RP), the distance (fd) from the viewpoint (VP) to the projection plane (PS) and the camera position (CP _n). ) Based on (3), the starting point (NP) and direction (NV) of the light beam are set.
According to the fourth aspect of the present invention, stereoscopic viewing of a desired object is realized even when the subject is large and the shooting space is limited, when it is difficult to fit within the angle of view of the camera in a predetermined arrangement, or when the actual object does not exist. be able to.

  According to the present invention, it is possible to provide a three-dimensional printed material production support apparatus that supports producing a three-dimensional printed material within a practical time without photographing an actual subject.

Diagram showing perspective projection Diagram showing parallel projection Diagram showing semi-perspective projection The figure which shows the structure of the three-dimensional printed matter 1 The figure which shows the relationship between the partial image Ip and the space projected. The figure which shows the production | generation process of the directivity image 6 based on the perspective projection image 5 Hardware configuration diagram of the three-dimensional printed material production support apparatus 10 Software configuration diagram of the three-dimensional printed material production support apparatus 10 The figure which shows the definition of gaze direction (theta) _n The figure which shows camera position CP in a world coordinate system Shows a perspective NP _c and direction NV _c of the light beam by the plug 23 in the camera coordinate system Rendering result of perspective projection image 5 as a comparative example Rendering result of directional image 6 as an embodiment Rendering result of directional image 6 as an embodiment Actual photograph of three-dimensional printed material 1 as an example

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
First, technical terms used in the present invention will be described with reference to FIGS.

FIG. 1 is a diagram showing perspective projection.
A projected image Ia shown in FIG. 1 is obtained by projecting a three-dimensional object Obj onto a projection plane PS (two-dimensional plane) by a perspective projection method with the camera position CP as a viewpoint. In perspective projection, the object Obj is projected onto the projection plane PS so that a human can see it. A photograph taken with a normal camera is based on a perspective projection technique. Also, perspective projection is widely used in three-dimensional CG (Computer Graphics).
Hereinafter, an image expressed by a perspective projection method is referred to as a perspective projection image.
As shown in FIG. 1, the projection image Ia, which is a perspective projection image, has a length in the X-axis direction and a length in the Y-axis direction that are both shorter than the object Obj.

FIG. 2 is a diagram showing parallel projection.
A projection image Ib shown in FIG. 2 is an image in which the object Obj is drawn on the projection plane PS by a parallel projection technique. In parallel projection, assuming that the viewpoint exists at infinity, the point of the object Obj is projected onto the projection plane PS. In FIG. 2, since the projection line (line connecting the viewpoint and the point of the object Obj) and the projection plane PS intersect perpendicularly, this is particularly called vertical projection among parallel projections.
As shown in FIG. 2, the projection image Ib has the same length in the X-axis direction and the length in the Y-axis direction as the object Obj.

FIG. 3 is a diagram showing semi-perspective projection.
A projected image Ic shown in FIG. 3 is an image in which the object Obj is drawn on the projection plane PS by a semi-perspective projection method. The semi-perspective projection is a perspective projection that is performed only in the vertical direction (Y-axis direction shown in FIG. 3). As shown in FIG. 3, in the semi-perspective projection, the y-coordinate and z-coordinate of the viewpoint are the same as the perspective projection (= y-coordinate and z-coordinate of the camera position CP), but the x-coordinate of the viewpoint is the vertical projection. It is the same (= x coordinate of the point to be seen through the object Obj).
Hereinafter, an image expressed by the semi-perspective projection method is referred to as a directional image.
As shown in FIG. 3, the projected image Ic, which is a directional image, has the same length in the X-axis direction as the object Obj, but the length in the Y-axis direction is shorter than the object Obj.

  Next, the three-dimensional printed material 1 according to the embodiment of the present invention will be described with reference to FIGS. 4 to 6. The three-dimensional printed material 1 is a printed material in which stereoscopic vision with the naked eye is realized. In the embodiment of the present invention, the three-dimensional printed material 1 uses a lenticular sheet 3.

FIG. 4 is a diagram illustrating the structure of the three-dimensional printed material 1.
As shown in FIG. 4, the structure of the three-dimensional printed material 1 is obtained by bonding a printed material on which the composite image 2 is printed and a lenticular sheet 3. The composite image 2 is printed by the method described in Patent Document 2, for example.

  The lenticular sheet 3 is a sheet in which a plurality of lenticular lenses L (m) (m is an integer satisfying 0 ≦ m <M) are arranged in a strip shape. Hereinafter, M is the number of lenticular lenses included in the lenticular sheet 3, and m is a subscript of the lenticular lens.

The synthesized image 2 is an image synthesized by associating many images with multiple viewpoints. The composite image 2 is a partial image Ip (n) that is a part of the directional image DI (n) corresponding to the incident light direction VA (n) (n is an integer satisfying 0 ≦ n <N) for each lenticular lens. , M) are arranged in order.
When an attempt is made to produce a three-dimensional printed material 1 with N viewpoints, N directional images DI (n) are also required.
Hereinafter, N is the number of viewpoints or the number of directional images, and n is a subscript of the viewpoint or directional image.

For example, the partial image Ip (0, 0),... Of the directional image DI (0),..., The directional image DI (n) is provided on the back surface (the surface that is not a semi-cylindrical curved surface) of the lenticular lens L (0). ) Partial images Ip (n, 0),..., And partial images Ip (N−1, 0) of directivity images DI (N−1) are arranged in order.
Further, for example, the partial image Ip (0, m) of the directional image DI (0),..., The directional image DI is provided on the back surface (the surface that is not a semi-cylindrical curved surface) of the lenticular lens L (m). The partial images Ip (n, m) of (n),..., The partial images Ip (N−1, m) of the directivity image DI (N−1) are sequentially arranged.
Further, for example, the partial image Ip (0, M−1),... Of the directional image DI (0) is provided on the back surface (the surface that is not a semi-cylindrical curved surface) of the lenticular lens L (M−1). A partial image Ip (n, M-1) of the directional image DI (n), ..., and a partial image Ip (N-1, M-1) of the directional image DI (N-1) are sequentially arranged. The

  When the three-dimensional printed material 1 is observed from the front of the lenticular sheet 3 (in the Z-axis direction shown in FIG. 4), the partial image Ip (n M) is visually recognized, and a partial image Ip (na, 0) corresponding to the direction VA (na) is visually recognized through the lenticular lens L (0). a is a value determined by the distance between the viewpoint and the lenticular sheet 3. Further, a partial image Ip (n + a, M-1) corresponding to the direction VA (n + a) is visually recognized through the lenticular lens L (M-1).

FIG. 5 is a diagram showing the relationship between the partial image Ip and the projected space.
An image seen from the viewpoint n through the lenticular lens L (m) is seen through the viewing space Vol (n, m) determined by the viewpoint n, the focal line 4 of the lenticular lens L (m), and the length of the lenticular lens L (m). Given as a projection. In other words, a portion of the directional image DI (n) that is perspective-projected only in the vertical direction (Y-axis direction shown in FIG. 5) at a position that can be seen from the viewpoint n through the lenticular lens L (m), that is, the partial image Ip ( By arranging n, m), stereoscopic vision can be realized.

FIG. 6 is a diagram showing a directional image generation process based on a perspective projection image.
Hereinafter, the perspective projection images are collectively referred to as “the perspective projection image 5”. In addition, when the directional images are collectively referred to as “directional images 6”.
The directional image 6 cannot be taken with a camera. Therefore, when producing the three-dimensional printed material 1 using a photographed image, as in Patent Document 1, a plurality of cameras (dedicated photographing devices) arranged in a horizontal direction are used to photograph an actual subject, and several hundred to several thousand are photographed. The number of perspective projection images 5 is taken. And the area | region equal to the partial image of the directional image 6 is cut out and acquired from each perspective projection image.

FIG. 6 is a plan view seen from the Y-axis direction of FIG. As shown in FIG. 6, in order to generate the directional image DI (n), each perspective projection image PI (0),..., PI (m), PI (m + 1),. From M−1), partial images Ip (n, 0),..., Ip (n, m), Ip (n, m + 1),. Synthesize.
When the directional images 6 are generated by this procedure, strictly, the perspective projection images 5 corresponding to the number of pixels in the horizontal direction are required for each directional image 6. For example, when the number of pixels in the horizontal direction is 1000, it is strictly necessary to capture 1000 perspective projection images 5 for each directional image 6.
In addition, by using interpolation between pixels, N (for example, N = 100) directional images from a set (for example, 1000) of one perspective projection image PI (0) to PI (M−1). DI (0) to DI (N-1) can also be generated.
However, even when only one directional image 6 is generated (when producing the three-dimensional printed material 1 with one field of view), the perspective projection images 5 corresponding to the number of pixels in the horizontal direction of the directional image 6 are necessary. is there.

If the directional image 6 is generated from the perspective projection image 5 using the existing 3D CG software, about 1000 sheets (corresponding to the number of pixels in the horizontal direction of the directional image 6) from the 3D CG model. It is necessary to render the perspective projection image 5. However, since the rendering operation takes a long time, rendering 1000 images is unrealistic.
Therefore, in the embodiment of the present invention, the number of images to be rendered is greatly reduced by the processing described later. Specifically, in the embodiment of the present invention, the number of images to be rendered is changed from the number of horizontal pixels (about 1000) of the directional image 6 to the number of viewpoints (the maximum number of viewpoints according to the method of Patent Document 2 is (About 100 sheets).
The number of pixels in the horizontal direction of the directional image 6 is the same as the number of lenses M included in the lenticular sheet 3.

Next, the three-dimensional printed material production support apparatus 10 according to the embodiment of the present invention will be described with reference to FIGS.
The three-dimensional printed material production support apparatus 10 is a computer that supports the production of the three-dimensional printed material 1. The three-dimensional printed material production support apparatus 10 generates a composite image 2 included in the three-dimensional printed material 1.

FIG. 7 is a hardware configuration diagram of the three-dimensional printed material production support apparatus 10. Note that the hardware configuration in FIG. 7 is an example, and various configurations can be adopted according to the application and purpose.
The three-dimensional printed material production support apparatus 10 includes a control unit 11, a storage unit 12, a media input / output unit 13, a communication control unit 14, an input unit 15, a display unit 16, a peripheral device I / F unit 17, and the like via a bus 18. Connected.

  The control unit 11 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), a RAM (Random Access Memory), and the like.

The CPU calls and executes a program stored in the storage unit 12, ROM, recording medium, or the like to a work memory area on the RAM, drives and controls each device connected via the bus 18, and a three-dimensional printed material production support device The process which 10 performs later which 10 performs is implement | achieved.
The ROM is a non-volatile memory and permanently holds a computer boot program, a program such as BIOS, data, and the like.
The RAM is a volatile memory, and temporarily stores programs, data, and the like loaded from the storage unit 12, ROM, recording medium, and the like, and includes a work area used by the control unit 11 for performing various processes.

The storage unit 12 is an HDD (hard disk drive), and stores a program executed by the control unit 11, data necessary for program execution, an OS (operating system), and the like. With respect to the program, a control program corresponding to an OS (operating system) and an application program for causing a computer to execute processing described later are stored.
Each of these program codes is read by the control unit 11 as necessary, transferred to the RAM, read by the CPU, and executed as various means.

The media input / output unit 13 (drive device) inputs / outputs data, for example, media such as a CD drive (-ROM, -R, -RW, etc.), DVD drive (-ROM, -R, -RW, etc.) Has input / output devices.
The communication control unit 14 includes a communication control device, a communication port, and the like, and is a communication interface that mediates communication between a computer and a network, and performs communication control between other computers via the network. The network may be wired or wireless.

The input unit 15 inputs data and includes, for example, a keyboard, a pointing device such as a mouse, and an input device such as a numeric keypad.
An operation instruction, an operation instruction, data input, and the like can be performed on the computer via the input unit 15.
The display unit 16 includes a display device such as a CRT monitor and a liquid crystal panel, and a logic circuit (such as a video adapter) for realizing a video function of the computer in cooperation with the display device.

The peripheral device I / F (interface) unit 17 is a port for connecting a peripheral device to the computer, and the computer transmits and receives data to and from the peripheral device via the peripheral device I / F unit 17. The peripheral device I / F unit 17 is configured by USB, IEEE 1394, RS-232C, or the like, and usually includes a plurality of peripheral devices I / F. The connection form with the peripheral device may be wired or wireless.
The bus 18 is a path that mediates transmission / reception of control signals, data signals, and the like between the devices.

FIG. 8 is a software configuration diagram of the three-dimensional printed material production support apparatus 10.
The storage unit 12 of the three-dimensional printed material production support apparatus 10 stores a modeling program 21, a rendering program 22, a plug-in 23, an image composition program 24, and the like. The control unit 11 of the three-dimensional printed material production support apparatus 10 reads out these program codes, moves them to the RAM, and executes them as various means.

The modeling program 21 is a CG program for defining and creating the shape data of the object Obj while executing interactive processing with the user. In the modeling program 21, the surface shape of the object Obj is expressed as a set of polygons (polygons such as triangles and quadrangles) on the virtual three-dimensional space, and various curves (NURBS curves, spline curves, Bezier curves, etc.) ) To create a free-form surface. The shape of the object Obj expressed in this way is the three-dimensional CG model 7.
The control unit 11 of the three-dimensional printed material production support apparatus 10 generates the three-dimensional CG model 7 of the object Obj by the function of the modeling program 21 and stores it in the storage unit 12.
The modeling program 21 is not particularly limited, and commercially available CG software may be used.

The rendering program 22 is a CG program for generating an image that should be taken by a virtual camera from a set scene (virtual stage). As the scene setting, an arrangement of the three-dimensional CG model 7, an arrangement of light sources, an arrangement of a virtual camera (= viewpoint), and the like are performed.
The control unit 11 of the three-dimensional printed material production support apparatus 10 calculates the shape and position of the three-dimensional CG model 7 and the degree of light hitting (glossiness) based on the set scene by the function of the rendering program 22. An image photographed by a virtual camera is generated and stored in the storage unit 12.
In the embodiment of the present invention, the image captured by the virtual camera is the directional image 6.

In the embodiment of the present invention, a ray tracing function included in a general rendering program 22 is used. Ray tracing is a technique for rendering by tracing light rays from a viewpoint to a light source. In ray tracing, a line is drawn from the viewpoint in the direction of each pixel on the projection plane, it is mathematically determined whether or not it intersects with the three-dimensional CG model 7, and reflection and refraction are repeated, and the search is repeated recursively. The calculation ends when there is no crossing with the three-dimensional CG model 7.
The rendering program 22 is not particularly limited, and commercially available CG software may be used as long as the ray tracing function is included.

The plug-in 23 is a plug-in program for defining various setting values for generating the directivity image 6 in the ray tracing function. The plug-in 23 extends or changes the function of the rendering program 22 and is executed in a form that is called from the rendering program 22.
The plug-in 23 sets, as setting values for generating the directional image 6, the line-of-sight direction with respect to the directional image 6, the position of the virtual camera, and the start point and direction of light rays incident on the projection surface. A function for calculating and setting (a ray starting point and direction in a ray tracing function) is provided. Details of the functions provided by the plug-in 23 will be described later with reference to FIGS. 9 to 11.
The embodiment of the present invention is not limited to this example, and the rendering program 22 may include the function of the plug-in 23.

The image composition program 24 generates a composite image 2 from the directivity image 6. As described above with reference to FIG. 4, the image composition program 24 for each lenticular lens, the partial image Ip (n) that is a part of the directional image DI (n) corresponding to the direction VA (n) of the incident light beam. , M) are arranged in order, and a composite image 2 is generated.
When the three-dimensional printed material 1 with the number of viewpoints N is to be produced, the control unit 11 of the three-dimensional printed material production support apparatus 10 generates one synthesized image 2 from the N directional images 6 by the function of the image synthesis program 24. It is generated and stored in the storage unit 12.

Next, functions provided by the plug-in 23 will be described with reference to FIGS. 9 to 11.
In the following, it is assumed that the three-dimensional printed material 1 having M lenses and N viewpoints included in the lenticular sheet 3 is produced as described above. Therefore, the number of pixels in the horizontal direction of the directional image 6 is M, and the number of created directional images 6 is N.

Figure 9 is a diagram showing the definition of the viewing direction theta _n.
In the composite image 2, a partial image Ip (n, m) that is a part of the directional image 6 is arranged on the left and right sides with the position where the line of sight is perpendicularly incident on the lenticular lens L (m) as the reference position 31. The At this time, the line-of-sight direction θ _n with respect to the _n- th partial image Ip (n, m) corresponds to the arrangement of the pixels 32 on the printing surface 30 (corresponding to the projection surface PS) as shown in FIG. A line-of-sight direction 34 for each pixel 32 is defined so as to pass through a focal point 33 of L (m). In FIG. 9, only five pixels 32 are shown to simplify the drawing, but the pixels 32 exist over the entire printing surface 30 as a matter of course.
When _expressed by a mathematical formula, the line-of-sight direction θ _n is defined as the following formula. Here, dpi is the printing resolution, and f is the focal length of the lenticular lens.

As described above, the control unit 11 of the three-dimensional printed material production support apparatus 10 uses the directional image I included in the three-dimensional printed material 1 based on the focal length f of the lenticular lens used in the three-dimensional printed material 1 and the print resolution dpi of the three-dimensional printed material 1. to set the line-of-sight direction θ _n for the _n. In particular, the control unit 11 calculates the line-of-sight direction θ _n so that the pixel 32 passes through the focal point 33 of the lenticular lens L (m) of the three-dimensional printed material 1 in correspondence with the arrangement of the pixels 32 on the printing surface 30 of the three-dimensional printed material 1. To do.

FIG. 10 is a diagram showing the camera position CP in the world coordinate system.
In FIG. 10, in the world coordinate system (X, Y, Z) of the virtual three-dimensional space, the object Obj, the projection plane PS, and the cameras C _{0 to} C _N-1 (hereinafter collectively referred to as “camera C”). ). The projection plane PS is arranged on the XY plane, and the horizontal width is M pixels. The camera reference position CP _{org is set} to (0, 0, Z ₀ ).
In the embodiment of the present invention, the parallel arrangement is used for the arrangement method of the camera C. That is, as shown in FIG. 10, the perpendicular lines drawn from the camera C to the projection plane PS (XY plane) are all arranged to be equal. In Figure 10, the length of the perpendicular line drawn to the projection plane PS from the camera C are all a Z _0. Then, the camera position CP _n is defined based on the line-of-sight direction θ _n defined as described above. When shown in a formula, the camera position CP _n is defined as follows.

As shown in FIG. 10, for example, the camera position CP ₀ of the camera _{C 0 is} the _{(Z 0 tanθ 0, 0,} Z 0). Further, for example, the camera position CP _n of the camera C _n is (Z ₀ tan θ _n , 0, Z ₀ ). Further, for example, the camera position CP _N-1 of the camera C _N-1 is (Z ₀ tan θ _N−1 , 0, Z ₀ ).

As described above, the control unit 11 of the three-dimensional printed material production support apparatus 10 sets the camera position CP _n based on the line-of-sight direction θ _n . In particular, the control unit 11 sets the camera arrangement method in parallel, and calculates the horizontal coordinate x _n of the camera position CP _n by the formula x _n = Z ₀ × tan θ _n .
Note that the value of Z ₀ may be arbitrarily set by the producer of the three-dimensional printed material 1.

FIG. 11 is a diagram illustrating the viewpoint NP _c and the direction NV _c of the light ray by the plug-in 23 in the camera coordinate system.
The directional image 6 is generated by giving the starting point and direction of the light ray passing through the pixel for all the pixels on the projection plane PS.
In FIG. 11, in the camera coordinate system (X _C , Y _C , Z _C ) of the virtual three-dimensional space, the object Obj, the projection plane PS _c , the viewpoint VP, and the line-of-sight space Vol (pentahedral) are arranged.
Here, Y _c = Y. Further, the distance from the viewpoint VP to the projection plane PS _c (PS) is fd, the coordinates of the viewpoint VP are (0, 0, fd), and the coordinates of the pixel RP to be rendered on the projection plane PS _c are (x _r , y _r , 0).
In the camera coordinate system shown in FIG. 11, the light ray start point NP _c and the direction NV _c for generating the directivity image 6 are defined as follows.

Next, the light beam direction NV _c is rotated around the Y _c axis so that the −Z _c direction in the camera coordinate system is the line-of-sight direction θ _n of the directivity image 6. At this time, when it rewrites the vector component, since the magnitude of the direction NV _c rays will change, after replacing the elevation φ for X _c Z _c plane, the calculation of theta _n rotation. When expressed by a mathematical formula, the direction NV of the light beam in the world coordinate system is calculated as the following formula.

Further, the starting point NP of the rays in the world coordinate system, taking into account the position relative to the camera position CP _n, is defined as follows.

Thus, the control unit 11 of the three-dimensional print production support device 10, for each rendered pixel RP, based from the viewpoint VP to the position CP _n of length fd and cameras to the projection plane PS, the starting point of the ray NP and direction NV Set. In particular, the control unit 11, the horizontal coordinate of the start point NP _c of light in the camera coordinate system and the horizontal coordinate x _r of rendered pixels RP, by performing the conversion from the world coordinate system to the camera coordinate system, A light ray start point NP in the world coordinate system is calculated.

As described above, the control unit 11 sets the start point and the direction of the light ray in the ray tracing function for all the pixels on the projection plane PS. Then, the control unit 11 calculates the shape and position of the three-dimensional CG model 7, the degree of light hitting (glossiness), and the like by the function of the rendering program 22, and determines the colors of all the pixels on the projection plane PS. .
Accordingly, the control unit 11 can generate the directional image 6 captured by the virtual camera lens (directional image capturing lens) without generating the perspective projection image 5.

The three-dimensional printed material 1 is produced using the three-dimensional printed material production support device 10. That is, the control unit 11 of the three-dimensional printed material production support apparatus 10 models a CG model of an object. Next, the control unit 11, to the projection plane PS, to set the position CP _n of the virtual camera, the starting point NP and direction NV of light rays incident on the projection plane PS from the position CP _n of the camera. Next, the control unit 11 creates a directional image 6 photographed by a virtual camera by tracing light rays with respect to the CG model based on the set value. Then, the control unit 11 creates the composite image 2 based on the directivity image 6. Thereafter, for example, by the method described in Patent Document 2, the printing apparatus prints the composite image 2, and the printed material is bonded to the lenticular sheet 3, thereby producing the three-dimensional printed material 1.
Here, as described above, the line-of-sight direction θ _n with respect to the directional image DI _n included in the three-dimensional printed material 1 is set based on the focal length f of the lenticular lens and the print resolution dpi of the three-dimensional printed material 1, and the camera position CP _n Is set based on the line-of-sight direction θ _n , and the light ray start point NP and direction NV are set for each rendering target pixel RP based on the distance fd from the viewpoint VP to the projection plane PS and the camera position CP _n. Is set.

Examples of the present invention will be described below with reference to FIGS. 12 to 15 are color photographs converted into gray scales due to limitations of the patent drawings.
In this example, “mental ray (registered trademark)” manufactured by “mental images GmbH” of Germany was used as CG software having the modeling program 21 and the rendering program 22. Then, the present inventors created a lens plug-in “DynaCube 3D (registered trademark) lens” for “Mental ray (registered trademark)” as the plug-in 23.
In the “DynaCube 3D (registered trademark) lens”, parameters such as the focal length f of the lenticular lens and the number of pixels M in the horizontal direction of the directional image 6 can be arbitrarily set. In addition, the directivity image 6 in which the viewpoint position is changed can be automatically generated.

FIG. 12 shows a rendering result of a perspective projection image 5 as a comparative example. In the comparative example, rendering was performed using a conventional camera lens (perspective projection method).
On the other hand, FIG. 13 and FIG. 14 show the rendering results of the directional image 6 as an example. In the example, rendering was performed using a “DynaCube 3D® lens”.
In both the comparative example and the example, the number of viewpoints N is 100, and the number of pixels M (lateral resolution) in the horizontal direction of the directional image 6 is 800.
Further, in order to compare the time required for generating the composite image 2, the rendering time for one sheet is 10 minutes for both the perspective projection image 5 and the directional image 6 so that the generated composite image 2 has the same image quality. did.

12 and 13 are images from substantially the same viewpoint. That is, both the images of FIGS. 12 and 13 are taken from a diagonal direction with respect to a rectangular grid pattern on the ground.
Further, the image of FIG. 14 is taken from a vertical direction of a certain side (or a parallel direction of a certain side) with respect to a rectangular grid pattern on the ground.

In the image of FIG. 12, it can be seen that the grid pattern on the ground is a straight line.
On the other hand, in the image of FIG. 13, it can be seen that the grid pattern on the ground is curved. Furthermore, it can be seen from the image in FIG. 14 that the grid pattern on the ground is a straight line. 13 and 14 well represent the characteristics of the directional image 6.

In the comparative example, the perspective projection image 5 is generated by the rendering process. As described above, the number of the perspective projection images 5 necessary for generating the composite image 2 is at least the number of pixels M in the horizontal direction of the directional image 6. Therefore, in the comparative example, 800 perspective projection images 5 are generated by the rendering process. Therefore, the rendering time in the comparative example was 10 minutes × 800 sheets = 8000 minutes≈133.3 hours≈5.6 days.
On the other hand, in the embodiment, the directional image 6 is generated by the rendering process, and the composite image 2 is generated based on the directional image 6. As described above, the number of directivity images 6 necessary for generating the composite image 2 is equal to the number N of viewpoints. Therefore, in the embodiment, 100 directional images 6 are generated by rendering processing. Therefore, the rendering time in the example took 10 minutes × 100 sheets = 1000 minutes≈16.7 hours≈0.7 days.
Thus, under the conditions of the present embodiment, the present invention was able to reduce the rendering time to 1/8 compared to the prior art.
If the rendering time is 0.7 days, it can be said that the three-dimensional printed material 1 can be produced within a sufficiently practical time.

FIG. 15 is an actual photograph of the three-dimensional printed material 1 as an example.
Needless to say, photographing with a camera is the same as when the three-dimensional printed material 1 is viewed from a specific viewing direction. In addition, since the lenticular sheet 3 is present on the front surface of the three-dimensional printed material 1, a blurred image is obtained by taking a photograph.
Actually, when the three-dimensional printed material 1 is observed with the naked eye, the shape of the automobile viewed from various angles is clearly observed according to the viewing direction.

  In the present embodiment, as the directivity image 6, an image obtained by photographing the same object Obj from various angles with a virtual camera is used, but the present invention is not limited to this example. For example, as the directional image 6, an image captured by moving the position of the object Obj may be used. Further, for example, as the directivity image 6, an image obtained by photographing a different object Obj may be used.

The three-dimensional printed material production support apparatus 10 of the present invention can produce the three-dimensional printed material 1 within a practical time without photographing a real subject.
In particular, since the 3D printed material 1 can be produced by the CG software, when the subject is large and the shooting space is limited, it is difficult to fit in the angle of view of the camera with a predetermined arrangement, even when there is no actual object, A three-dimensional printed material 1 can be produced.

  The preferred embodiments of the three-dimensional printed material production support apparatus and the like according to the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes or modifications can be conceived within the scope of the technical idea disclosed in the present application, and these naturally belong to the technical scope of the present invention. Understood.

1 ... 3D printed material 2 ... Composite image 3 ... Lenticular sheet 4 ... Focus line 5 ... Perspective projection image 6 ... Directivity image 7 ... 3D CG model 10 ... 3D Print Production Support Device 11 ......... Control Unit 12 ......... Storage Unit 21 ......... Modeling Program 22 ......... Rendering Program 23 ......... Plug-in 24 ......... Image Composition Program Obj ......... Object PS ... …… Projection plane CP ……… Camera position DI ……… Directional image Ip ……… Partial image Vol ……… Line of sight L ……… Lenticular lens C ……… Camera RP ……… Rendering target pixel VP …… … Viewpoint NP ……… Beginning point of rays NV ……… Direction of rays

Claims (7)

A three-dimensional printed material production support apparatus that supports the production of a three-dimensional printed material that realizes a stereoscopic view of a desired object,
Setting means for setting a virtual camera position (CP _n ) and a starting point (NP) and direction (NV) of a light ray incident on the projection plane (PS) with respect to the projection plane (PS);
Rendering means for creating an image of the object photographed by the camera by tracking the ray with respect to a CG model of the object based on a value set by the setting means;
Comprising
Based on the focal length (f) of the lenticular lens used in the three-dimensional printed material and the printing resolution (dpi) of the three-dimensional printed material, the setting means is a line-of-sight direction (DI _n ) included in the three-dimensional printed material ( θ _n ) is set, the camera position (CP _n ) is set based on the line-of-sight direction (θ _n ), and the projection plane (PS) from the viewpoint (VP) for each rendering target pixel (RP). ) And a camera position (CP _n ) to set a starting point (NP) and a direction (NV) of the light beam. The setting means uses the horizontal coordinate of the start point (NP _c ) of the ray in the camera coordinate system as the horizontal coordinate (x _r ) of the rendering target pixel (RP), and converts the world coordinate system to the camera coordinate system. The three-dimensional printed matter production support apparatus according to claim 1, wherein a starting point (NP) of the light ray in the world coordinate system is calculated by performing. The setting means sets the camera arrangement method to parallel arrangement, and x _n = the length of the perpendicular drawn from the camera to the projection plane PS (Z ₀ ) × tan θ _{n by} the expression of the camera position (CP _n 3) The horizontal coordinate (xn) of (3) is calculated. The setting unit calculates the line-of-sight direction (θ _n ) so as to pass through the focal point of the lenticular lens L (m) of the three-dimensional printed material from the pixels in correspondence with the arrangement of the pixels on the printing surface of the three-dimensional printed material. The three-dimensional printed material production support apparatus according to claim 3. Setting means for setting a virtual camera position (CP _n ) and a starting point (NP) and direction (NV) of a light ray incident on the projection plane (PS) with respect to the projection plane (PS). And based on the value set by the setting means, the ray is traced with respect to a CG model of a desired object, thereby functioning as a rendering means for creating an image of the object photographed by the camera. A plug-in program for
Directivity included in the three-dimensional printed material based on the focal length (f) of the lenticular lens used in the three-dimensional printed material for realizing the stereoscopic view of the desired object and the printing resolution (dpi) of the three-dimensional printed material. A line-of-sight direction (θ _n ) with respect to the image (DI _n ) is set, a position (CP _n ) of the camera is set based on the line-of-sight direction (θ _n ), and a viewpoint for each rendering target pixel (RP) Based on the distance (fd) from the (VP) to the projection plane (PS) and the position (CP _n ) of the camera, the starting point (NP) and direction (NV) of the light beam are set. A plug-in program. A three-dimensional printed material production method for producing a three-dimensional printed material that realizes a stereoscopic view of a desired object,
A modeling step in which a computer models a CG model of the object;
A setting step in which the computer sets a virtual camera position (CP _n ) and a start point (NP) and a direction (NV) of a light ray incident on the projection plane (PS) with respect to the projection plane (PS). When,
A rendering step in which a computer creates an image of the object photographed by the camera by tracking the ray with respect to the CG model based on the value set by the setting step;
Including
The setting step includes a line-of-sight direction (DI _n ) with respect to a directional image (DI _n ) included in the three-dimensional print based on a focal length (f) of a lenticular lens used in the three-dimensional print and a print resolution (dpi) of the three-dimensional print. θ _n ) is set, the camera position (CP _n ) is set based on the line-of-sight direction (θ _n ), and the projection plane (PS) from the viewpoint (VP) for each rendering target pixel (RP). ), And the position (CP _n ) of the camera, the starting point (NP) and direction (NV) of the light beam are set. A printed material on which a composite image, which is an image obtained by combining a number of images corresponding to a desired object in correspondence with multiple viewpoints, and a lenticular sheet are bonded together to realize a stereoscopic view of the object,
A computer models a CG model of the object, and with respect to the projection plane (PS), a virtual camera position (CP _n ) and a start point (NP) and direction of a light ray incident on the projection plane (PS) (NV) is set, and based on the set value, the light beam is traced with respect to the CG model to create a directional image of the object photographed by the camera, and the directional image Create a composite image based on
A printing device for printing the composite image on the printed matter;
Based on the focal length (f) of the lenticular lens used for the three-dimensional printed material and the printing resolution (dpi) of the three-dimensional printed material, the line-of-sight direction (θ _n ) for the directional image (DI _n ) included in the three-dimensional printed material is set. Then, the position (CP _n ) of the camera is set based on the line-of-sight direction (θ _n ), and the distance from the viewpoint (VP) to the projection plane (PS) for each rendering target pixel (RP) ( A three-dimensional print produced by setting the start point (NP) and direction (NV) of the light beam based on fd) and the position (CP _n ) of the camera.