Optical illusion object, display device for optical illusion object, display method of optical illusion object, information processing device, and manufacturing method of optical illusion object

Abstract

To provide an optical illusion object that is compatible with a new exhibition method.SOLUTION: The optical illusion object exhibits a first state where no first medium (M1) exists between a viewpoint (VP) and an illusional object (whose contour line C), resulting in a first perceptual shape as viewed from the viewpoint (VP). In a second state where the first medium (M1) exists between the viewpoint (VP) and the illusion object (whose contour line C), a second perceptual shape (whose contour line E) viewed through the first medium (M1), which causes refraction from the viewpoint (VP), is structurally different from the first perceptual shape.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present disclosure relates to an optical illusion three-dimensional object, an optical illusion three-dimensional object exhibition device, an optical illusion three-dimensional object exhibition method, an information processing device, and an optical illusion three-dimensional object manufacturing method. [Background technology]

[0002] There is a known phenomenon in which we perceive things as different from reality, and this is called an "illusion." Visual illusions are called "optical illusions," and a wide variety of optical illusions are known. In recent years, it has been discovered that among the three-dimensional objects that were thought to be possible to draw but impossible to create in reality, there are some that can actually be created by utilizing optical illusions. There are also known three-dimensional objects that produce an optical illusion in which the depth appears to be reversed (for example, the hollow mask illusion). Three-dimensional objects that use or produce optical illusions in this way are called "optical illusion three-dimensional objects."

[0003] Patent Document 1 discloses an illusionary three-dimensional group that includes multiple illusionary three-dimensional components that are designed so that a first perceived shape seen from a first viewpoint and a second perceived shape seen from a second viewpoint are different. Patent Document 1 further discloses a display method in which a flat mirror is placed in a position where the second viewpoint is in a (mirror) symmetrical relationship with the first viewpoint, so that the (first perceived) shape when the illusionary three-dimensional group is viewed directly from the first viewpoint appears to be different from the (second perceived) shape of the illusionary three-dimensional group reflected in the mirror.

[0004] Non-patent document 1 further discloses a display method in which, by projecting light onto an optical illusion three-dimensional object from a second viewpoint, the shape of the optical illusion three-dimensional object when viewed directly (first viewing) appears different from the shape of the optical illusion three-dimensional object when viewed through a shadow (second viewing) from a first viewpoint.

[0005] Depending on their characteristics and display methods, optical illusion solids are variously named, such as "trompe l'oeil solids," "impossible motion solids," "transforming solids," "transparent solids," "topology-disrupting solids," "soft solids," and "height-inverted solids."

[0006] It should be noted that the "optical illusion" used in optical illusion 3D is a phenomenon resulting from human nature, and is different from visual effects such as zooming, inversion, and reflection caused by lenses. For example, Patent Document 2 discloses a visual effect in which a background image is projected onto a reflective surface. Also, Non-Patent Document 2 discloses a phenomenon in which the direction of an arrow changes when water is poured into a cup. The reversal of direction in Non-Patent Document 2 is not an optical illusion, but simply indicates the phenomenon of refraction. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2019-59190 [Patent Document 2] Special Publication No. 2010-509138 [Non-patent literature]

[0008] [Non-Patent Document 1] "The World of 3D Illusions" Episode 18: Shadow Transformation (Released: June 22, 2020) [Non-patent document 2] "The arrow is pointing in the opposite direction!? Let's use the refraction of light," (Published URL: https: / / www.science-kido.com / single-post / refraction-of-light / , Published date: May 4, 2020) Summary of the Invention [Problem to be solved by the invention]

[0009] The inventors of the present disclosure have explored new methods for displaying optical illusion three-dimensional objects.

[0010] One aspect of the present disclosure aims to realize an optical illusion three-dimensional object, an optical illusion three-dimensional object exhibition device, an optical illusion three-dimensional object exhibition method, an information processing device, and an optical illusion three-dimensional object manufacturing method that are adapted to new exhibition methods. [Means for solving the problem]

[0011] In order to solve the above problem, an optical illusion three-dimensional object according to one embodiment of the present disclosure is an optical illusion three-dimensional object that is configured such that in a first state in which no first medium exists between a viewpoint and the optical illusion three-dimensional object, a first perceived shape seen from the viewpoint is different from a second perceived shape seen from the viewpoint through the first medium that causes refraction in a second state in which the first medium exists between the viewpoint and the optical illusion three-dimensional object.

[0012] In order to solve the above problem, an exhibition device for an optical illusion three-dimensional object according to one embodiment of the present disclosure is configured to include an optical illusion three-dimensional object according to one embodiment of the present disclosure, and a state switching unit that switches between the first state and the second state by changing the arrangement of the first medium relative to the optical illusion three-dimensional object.

[0013] In order to solve the above problem, a method for displaying an optical illusion three-dimensional object according to one embodiment of the present disclosure is a method for displaying an optical illusion three-dimensional object according to one embodiment of the present disclosure, which includes a state switching step of switching between the first state and the second state by changing the arrangement of the first medium relative to the optical illusion three-dimensional object.

[0014] In order to solve the above problem, an information processing device according to one embodiment of the present disclosure includes an acquisition unit that acquires, in a first plane, a plurality of first points that constitute a first contour line and a plurality of second points that constitute a second contour line that is different from the first contour line; an intersection point identification unit that identifies, in each of a plurality of second planes that intersect with the first contour line and the second contour line, an intersection point between a line that passes through the first point and extends in a first direction and a line that passes through the second point and extends in a second direction; and a shape information generation unit that generates shape information of an optical illusion three-dimensional object whose first perceived shape when viewed from the first direction and whose second perceived shape when viewed from the second direction are different based on the plurality of intersection points identified in the plurality of second planes, wherein the first perceived shape has a shape corresponding to the first contour line and the second perceived shape has a shape corresponding to the second contour line.

[0015] The information processing device may be realized by a computer, in which case a control program that causes the computer to operate as each part (software element) of the information processing device to realize the information processing device on a computer, and a computer-readable recording medium on which the control program is recorded, also fall within the scope of this disclosure.

[0016] In order to solve the above problem, a method for manufacturing an optical illusion three-dimensional object according to one embodiment of the present disclosure is a method including a step of manufacturing the optical illusion three-dimensional object based on the shape information generated by the shape information generation unit of an information processing device according to one embodiment of the present disclosure. [Effects of the Invention]

[0017] According to one aspect of the present disclosure, it is possible to realize an optical illusion three-dimensional object, an optical illusion three-dimensional object exhibition device, an optical illusion three-dimensional object exhibition method, an information processing device, and an optical illusion three-dimensional object manufacturing method that are adapted to a new exhibition method. [Brief explanation of the drawings]

[0018] [Figure 1] FIG. 1 is a perspective view showing an optical illusion in an example of an optical illusion three-dimensional object according to the present disclosure. [Figure 2]FIG. 2 is a perspective view showing another optical illusion in the example of the optical illusion three-dimensional object shown in FIG. 1. [Figure 3] 1 is a schematic diagram showing an example of an optical illusion three-dimensional object display device according to the present disclosure. FIG. [Figure 4] 10 is a schematic diagram showing another example of an optical illusion three-dimensional object display device according to the present disclosure. FIG. [Figure 5] 1 is a flow chart showing an example of a design method for an optical illusion three-dimensional object according to the present disclosure. [Figure 6] 1 is a block diagram illustrating an example of an information processing device that executes part of the design of an optical illusion three-dimensional object according to the present disclosure. [Figure 7] FIG. 1 is a perspective view showing a first perceived shape envisioned by the inventors in Example 1 of the present disclosure. [Figure 8] FIG. 10 is a perspective view showing a second perceived shape envisioned by the inventors in the first embodiment of the present disclosure. [Figure 9] FIG. 10 is a diagram showing a photograph of an optical illusion three-dimensional object manufactured in Example 2 of the present disclosure, in a first state in which the optical illusion three-dimensional object is in air, and a first perceived shape. [Figure 10] FIG. 10 is a diagram showing a photograph of the optical illusion three-dimensional object manufactured in Example 2 of the present disclosure in a second state in which the optical illusion three-dimensional object is placed underwater, and a second perceived shape. [Figure 11] FIG. 1 is a perspective view showing an optical illusion in an example of an optical illusion three-dimensional object according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0019] In this disclosure, the actual three-dimensional shape of a three-dimensional object is referred to as the "actual shape." A person viewing the three-dimensional object first obtains a planar figure that does not contain depth information, and then secondarily reconstructs and perceives the three-dimensional shape based on this planar figure. In this disclosure, directing one's gaze toward an object and the state of being directed toward it are referred to as "seeing" or "visually recognizing." "Perceiving" can also be expressed as "recognizing."

[0020] [Embodiment 1] (3D optical illusion object) FIG. 1 is a perspective view showing an optical illusion of an example of an optical illusion three-dimensional object according to the present disclosure. Contour line C is the contour line of a portion of the optical illusion three-dimensional object. In the first state shown in FIG. 1, a second medium M2 exists around the optical illusion three-dimensional object, and a second medium M2 also exists around the viewpoint VP. No first medium exists between a given viewpoint VP and the optical illusion three-dimensional object. In the first state, a first line of sight L1_i from the viewpoint VP to a point Ri on the contour line C of the actual shape of the optical illusion three-dimensional object passes through the second medium M2 and is not refracted. Here, the number of samples for the contour line C is (n+1), where i is an integer between 0 and n. Point Ri on the contour line C corresponds to a first point Pi where the first line of sight L1_i or an extension of the first line of sight L1_i intersects with the first plane F1. Therefore, a first contour line A including the first point Pi is obtained from the contour line C including point Ri. Then, when a person views the illusionary three-dimensional object from viewpoint VP in the first state, for example, they first acquire a first planar figure having a first contour line A (or a figure obtained by projecting the first planar figure onto a plane perpendicular to the first line of sight L1_i), and reconstruct the three-dimensional figure based on the first planar figure (or the projected figure). As a result of this reconstruction, they perceive a first perceived shape K1 having a contour line D corresponding to the first contour line A.

[0021] FIG. 2 is a perspective view showing another optical illusion for the example of the optical illusion three-dimensional object shown in FIG. 1. In the second state shown in FIG. 2, a first medium M1 exists between the viewpoint VP and the optical illusion three-dimensional object. More specifically, in the second state, a first medium M1 exists around the optical illusion three-dimensional object, and a second medium M2 exists around the viewpoint VP. In other words, a second medium M2 exists between the first medium M1 and the viewpoint VP. The first medium M1 and the second medium M2 have different refractive indices. For example, the first medium M1 may be water, and the second medium M2 may be air. In the second state, a second line of sight L2_i from the viewpoint VP to a point Ri on the contour C of the actual shape of the optical illusion three-dimensional object passes through the second medium M2 and the first medium M1 and is refracted at the interface BS between the second medium M2 and the first medium M1. Point Ri on contour C corresponds to second point Qi, where the refracted second line of sight L2_i or the extension of the refracted second line of sight L2_i intersects with first plane F1. Therefore, a second contour B including second point Qi is obtained from contour C including point Ri. Then, a person viewing the illusory three-dimensional object from viewpoint VP in the second state first obtains a second planar figure having second contour B (or a figure obtained by projecting the second planar figure onto a plane perpendicular to second line of sight L2_i) and reconstructs the three-dimensional figure based on the second planar figure (or the projected figure). As a result of this reconstruction, the person perceives a second perceived shape K2 having a contour E corresponding to second contour B.

[0022] The first perceptual shape K1 and the second perceptual shape K2 are three-dimensional shapes that are generated by an optical illusion and differ from the real shapes, and furthermore, are three-dimensional shapes that differ from each other. Specifically, a curved portion of the contour line D of the first perceptual shape K1 corresponds to a curved or straight portion of the contour line E of the second perceptual shape K2, a curved portion of the contour line D corresponds to a curved or straight portion of the contour line E, a straight portion of the contour line D corresponds to a curved or curved portion of the contour line E, the bending directions of corresponding curved portions of the contour line D and the contour line E are different, and / or the bending directions and / or curvatures of corresponding curved portions of the contour line D and the contour line E are different.

[0023] The second plane Ni is perpendicular to the interface BS. For example, in an xyz Cartesian coordinate system, when the interface BS is parallel to the xy plane, the second plane Ni is parallel to the z axis. Point Ri on the contour C of the optical illusion three-dimensional object, first point Pi on the first contour A of the first two-dimensional figure, and second point Qi on the second contour B of the second two-dimensional figure are all located on the same second plane Ni.

[0024] In the first and second states, the optical illusion three-dimensional object (a three-dimensional object with a real shape) according to the present disclosure is the same object, and the viewpoint VP is in the same direction relative to the optical illusion three-dimensional object. However, in the first state, when the first medium M1 does not exist between the viewpoint VP and the optical illusion three-dimensional object, a first perceived shape K1 is obtained by viewing the optical illusion three-dimensional object from the viewpoint VP. In the second state, when the first medium M1 exists between the viewpoint VP and the optical illusion three-dimensional object, a second perceived shape K2 is obtained by viewing the optical illusion three-dimensional object from the viewpoint VP through the first medium M1 that causes refraction.

[0025] An optical illusion three-dimensional object utilizing refraction can be designed using the following procedure: Determine the interface and refractive index of the first medium M1 and the second medium M2. Determine the direction of the line of sight (first line of sight L1_i) in the first state (determine the position of the viewpoint VP). Determine the direction of the line of sight (second line of sight L2_i) in the second state, where refraction occurs. Determine the first plane F1. Determine the first perceived shape K1 with a contour D that is recognized when the optical illusion three-dimensional object is viewed from the first line of sight L1_i in the first state. Alternatively, determine the shape of the optical illusion three-dimensional object viewed from the first line of sight L1_i in the first state (the shape obtained by projecting contour D onto a plane perpendicular to the first line of sight L1_i). Then, project contour D onto the first plane F1 to determine the first contour A. Also, determine the second perceived shape K2 with a contour E that is recognized when the optical illusion three-dimensional object is viewed from the second line of sight L2_i in the second state. Alternatively, the shape of the optical illusion three-dimensional object when viewed from the second line of sight L2_i in the second state (the shape obtained by projecting the contour line E onto a plane perpendicular to the second line of sight L2_i) is determined. Then, the contour line E is projected onto the first plane F1 to determine the second contour line B. However, if the first contour line A can be determined without projecting the contour line D onto the first plane F1, the first contour line A may be determined directly. Also, if the second contour line B can be determined without projecting the contour line E onto the first plane F1, the second contour line B may be determined directly. The first line of sight L1_i is along the first direction D1, and the second line of sight L2_i in the first medium M1 is along the second direction D2. Note that the first plane F1 does not have to be parallel to the interface BS. The first plane F1 may be perpendicular to either the first line of sight L1_i or the second line of sight L2_i.

[0026] The intersection of the second plane Ni, which is parallel to the first line of sight L1_i and the second line of sight L2_i, and the first contour line A is identified as the first point Pi. The intersection of the second plane Ni and the second contour line B is identified as the second point Qi. The intersection point Ri of a line passing through the first point Pi and parallel to the first direction D1 and a line passing through the second point Qi and parallel to the second direction D2 is identified. The intersection point Ri on each of the multiple second planes Ni is identified in the same manner. The multiple intersection points Ri form the contour of the optical illusion three-dimensional object. In this way, an optical illusion three-dimensional object whose perceived shape differs depending on whether or not the first medium M1 is present can be designed from two planar figures. The other contours of the optical illusion three-dimensional object can be identified using the same procedure.

[0027] 1 and 2, the viewpoint VP is located at infinity from the optical illusion three-dimensional object, the first line of sight L1_i is along the first direction D1, and the second line of sight L2_i is along the first direction D1 in the second medium M2 and along the second direction D2 in the first medium M1. The scope of the present disclosure is not limited to this and includes configurations in which the viewpoint VP is located at a finite distance from the optical illusion three-dimensional object.

[0028] In the second state, a second medium M2 may be present, causing refraction at the interface with the first medium M1. The refractive index of the second medium M2 may be different from that of the first medium M1. The optical illusion three-dimensional object can be designed using the above procedure regardless of whether the refractive index of the second medium M2 is greater than or equal to that of the first medium M1. For example, the refractive index of the first medium M1 may be 1.3 or greater but less than 1.35, and the refractive index of the second medium M2 may be 1.1 or less. Alternatively, the refractive index of the first medium M1 may be 1.35 or greater but less than 2.0, and the refractive index of the second medium M2 may be 1.1 or less. Alternatively, the refractive index of the first medium M1 may be 1.3 or greater but less than 1.35, and the refractive index of the second medium M2 may be 1.35 or greater but less than 2.0. For example, the refractive index of the first medium M1 may be 1.35 or more and 2.0 or less, and the refractive index of the second medium M2 may be 1.3 or more and less than 1.35. A medium with a refractive index of 1.1 or less includes vacuum and gases such as air. A medium with a refractive index of 1.3 or more and less than 1.35 includes water. A medium with a refractive index of 1.35 or more and 2.0 or less includes oil and glass. The oil may be, for example, an edible oil such as olive oil, or a non-edible oil such as mineral oil or silicone oil.

[0029] (Display device for optical illusions) FIG. 3 is a schematic diagram showing an example of an exhibition device for an optical illusion three-dimensional object according to the present disclosure. FIG. 4 is a schematic diagram showing another example of an exhibition device for an optical illusion three-dimensional object according to the present disclosure. As shown in FIGS. 3 and 4, the exhibition device 3 according to the present disclosure includes at least an optical illusion three-dimensional object 1 according to the present disclosure and a state switching unit 4 that switches between a first state and a second state by changing the arrangement of a first medium M1 relative to the optical illusion three-dimensional object 1. The first medium M1 may be a liquid, and the state switching unit 4 can switch from the first state to the second state by placing the liquid between the optical illusion three-dimensional object 1 and a viewpoint VP or around the optical illusion three-dimensional object 1. The exhibition device 3 may also include a guide display that guides the viewer to the viewpoint VP, as appropriate.

[0030] In the example shown in Figure 3, the optical illusion three-dimensional object 1 is fixed on a base 5 in a water basin WP, the first medium M1 is water, and the second medium M2 is air. The state switching unit 4 includes a water fountain device 41 that spouts water into the water basin WP, and a drainage channel 42 that drains the water from the water basin WP. The state switching unit 4 can change the position of the first medium M1 relative to the optical illusion three-dimensional object 1 by changing the water level in the water basin WP.

[0031] The optical illusion three-dimensional object 1 is not limited to being placed in a water basin WP, but may be placed in any container such as a water channel, a water tank, or a cup. The state switching unit 4 is not limited to being placed in a fountain device 41, but may include any device that adds the first medium M1 to the container, such as a water drop device, a water spring device, or a water discharge device, and is not limited to being placed in a drainage channel 42, but may include any device that removes the first medium M1 from the container, such as a pump.

[0032] In the example shown in Figure 4, the optical illusion three-dimensional object 1 is rotatably attached to a waterwheel 43 installed in a waterway WC, with the first medium M1 being water and the second medium M2 being air. The state switching unit 4 includes the waterwheel 43, and the optical illusion three-dimensional object 1 moves with the rotation of the waterwheel 43, thereby changing the position of the first medium M1 relative to the optical illusion three-dimensional object 1. When the viewpoint VP is sufficiently far from the optical illusion three-dimensional object compared to the movement distance of the optical illusion three-dimensional object 1, the change in the line of sight is negligibly small even when the optical illusion three-dimensional object 1 moves. When the viewpoint VP is relatively close to the optical illusion three-dimensional object, the state switching unit 4 may further include a mechanism for moving the viewpoint VP in the same direction by the same distance as the optical illusion three-dimensional object 1.

[0033] The optical illusion three-dimensional object 1 is not limited to the waterwheel 43, but may include any device, such as a movable base, that can submerge the optical illusion three-dimensional object 1 in the first medium M1 or lift it up from the first medium M1.

[0034] The switching between the first state and the second state by the state switching unit 4 may be achieved by moving the first medium M1, by moving the optical illusion three-dimensional object 1, or by a combination of both.

[0035] (Display method for optical illusion objects) The optical illusion three-dimensional object according to the present disclosure is effectively exhibited so that it can be switched between the first state and the second state as appropriate. In other words, it is beneficial for the method of exhibiting an optical illusion three-dimensional object according to the present disclosure to include a state switching step of switching between the first state and the second state by changing the arrangement of the first medium M1 relative to the optical illusion three-dimensional object.

[0036] As shown in Figure 3, the optical illusion three-dimensional object 1 according to the present disclosure may be placed in a container such as a water basin WP, a water channel, a water tank, or a cup so that the optical illusion three-dimensional object 1 is submerged in the first medium M1 during periods when the amount of the first medium M1 is large, and appears above the first medium M1 during periods when the amount of the first medium M1 is small (or when the first medium M1 is absent). The first and second states are switched by varying the amount of the first medium M1. The amount of the first medium M1 may be varied artificially, for example, by operating a fountain device 41 and a water gate, or may vary naturally due to precipitation, evaporation, etc.

[0037] As shown in Figure 4, the optical illusion three-dimensional object 1 according to the present disclosure may be attached to a moving body such as a water wheel 43 so that the optical illusion three-dimensional object 1 is submerged in a first medium M1 or appears above the first medium M1. The moving body may be moved artificially or naturally.

[0038] (Method of designing optical illusion solids) FIG. 5 is a flow diagram illustrating an example of a method for designing an optical illusion three-dimensional object according to the present disclosure. As shown in FIG. 5, first, a first plane figure is obtained by projecting a first perceived shape K1 onto a first plane F1 from a first direction D1 or the opposite direction of the first direction D1 (step S10). A second plane figure is obtained by projecting a second perceived shape K2 onto the first plane F1 from a second direction D2 that is non-parallel to the first direction D1 or the opposite direction of the second direction D2 (step S12). In step S10, the first plane figure may be drawn geometrically, or a function representing the first plane figure may be calculated algebraically. In step S20, the second plane figure may be drawn geometrically, or a function representing the second plane figure may be calculated algebraically. The sizes and positions of the first and second plane figures may be adjusted as appropriate.

[0039] Next, for each of the second planes Ni, a first point Pi where the second plane Ni intersects with the first contour line A of the first planar figure is obtained (step S20), and a first line passing through the first point Pi and extending along the first direction D1 is obtained (step S30). Similarly, a second point Qi where the second plane Ni intersects with the second contour line A of the second planar figure is obtained (step S22), and a second line passing through the second point Qi and extending along the second direction D2 is obtained (step S32). Then, a point Ri where the first line and the second line intersect is identified (step S40). These steps may be performed using a geometric method or an algebraic method. Furthermore, these steps may be performed in a different order. For example, steps S12, S22, and S32 may be performed after steps S10, S20, and S30 are completed.

[0040] Next, shape information indicating the actual shape of the optical illusion three-dimensional object 1 is generated based on the identified multiple intersection points Ri (step S50). The multiple intersection points Ri are included in the points that make up the contour line C of the optical illusion three-dimensional object 1. The contour line C may be obtained by appropriately interpolating between the multiple intersection points Ri. The multiple intersection points Ri may correspond to the contour of the entire optical illusion three-dimensional object 1 or to a partial contour of the optical illusion three-dimensional object 1. For example, the multiple intersection points Ri may indicate the contour of the top surface of the optical illusion three-dimensional object 1, and the structure between the surface on which the optical illusion three-dimensional object 1 is placed and the top surface of the optical illusion three-dimensional object 1 may be appropriately supplemented.

[0041] (Information processing device) 6 is a block diagram showing an example of an information processing device that executes part of the design of an optical illusion three-dimensional object according to the present disclosure. As shown in FIG. 6, the information processing device 2 includes at least an acquisition unit G1, an intersection point identification unit G2, and a shape information generation unit G3. The information processing device 2 may also include an input / output interface G4 as needed.

[0042] The acquisition unit G1 receives information indicating a first contour A of a first planar figure and a second contour B of a second planar figure on the first plane F1 from outside the information processing device 2 or from another part within the information processing device 2. The second contour B is different from the first contour A. The acquisition unit G1 further receives information indicating a plurality of second planes Ni and samples from the first contour A and the second contour B according to the plurality of second planes Ni. As a result, the acquisition unit G1 acquires, on the first plane F1, a plurality of first points Pi that constitute the first contour A and are located on the plurality of second planes Ni, respectively, and a plurality of second points Qi that constitute the second contour B and are located on the plurality of second planes Ni, respectively.

[0043] The intersection identifying unit G2 receives information indicating a plurality of first points Pi and a plurality of second points Qi from the acquiring unit G. The intersection identifying unit G2 then acquires a first straight line passing through the first point Pi and extending in a first direction D1, and acquires a second straight line passing through the second point Qi and extending in a second direction D2, on each of a plurality of second planes Ni that intersect with the first contour line A and the second contour line B. The intersection identifying unit G2 then identifies an intersection Ri between the first straight line and the second straight line on each of the plurality of second planes Ni.

[0044] The shape information generation unit G3 receives information indicating the multiple intersections R from the intersection identification unit G2. The shape information generation unit G3 generates shape information based on the multiple intersections Ri. The shape information indicates the actual shape of the optical illusion three-dimensional object 1, in which a first perceptual shape K1 viewed from a first direction D1 and a second perceptual shape K2 viewed from a second direction D2 are different. The first perceptual shape K1 has a three-dimensional shape with a contour line D corresponding to the first contour line A, and the second perceptual shape K2 has a three-dimensional shape with a contour line E corresponding to the second contour line B.

[0045] The input / output interface G4 may download information indicating the first contour line A and the second contour line B from an external device (for example, the Internet or external storage). Alternatively, a user may use the input / output interface G4 to input information indicating the first contour line A and the second contour line B. The input / output interface G4 may retrieve drawing data from another information processing device on which a CAD application is installed and extract information indicating the first contour line A and the second contour line B from the drawing data.

[0046] The input / output interface G4 may output the shape information of the optical illusion three-dimensional object 1 to an external device (such as a 3D printer, etc.). The input / output interface G4 may also display a 3D model constructed according to the shape information of the optical illusion three-dimensional object 1 on a display device.

[0047] 1 and 2, the second direction D2 may be the direction of travel of a ray or line of sight traveling through the first medium M1 when the ray or line of sight traveling along the first direction outside the first medium M1 is refracted at an interface BS with the first medium M1 on the opposite side of the intersection point Ri from the first direction D1. The relative refractive indices inside and outside the first medium M1, the orientation of the interface BS of the first medium M1, the first direction D1, and the second direction D2 satisfy Snell's law. As a result, the first perceived shape K1 of the optical illusion three-dimensional object 1 viewed from the first direction D1 in the first state in which the first medium M1 is absent differs from the second perceived shape K2 of the optical illusion three-dimensional object 1 viewed from the first direction D1 through the first medium that causes refraction in the second state in which the first medium M1 is present.

[0048] The multiple second planes Ni may be parallel to each other. This setting may be applied when the viewpoint VP is far from the illusionary three-dimensional object 1, i.e., when it is substantially at infinity. Alternatively, the multiple second planes Ni may intersect with each other so as to pass through a single viewpoint VP. This setting may be applied when the viewpoint VP is close to the illusionary three-dimensional object 1, i.e., when it is substantially at a finite distance.

[0049] [Software implementation example] The functions of the information processing device 2 (hereinafter referred to as the "device") can be realized by a program for causing a computer to function as the device, and a program for causing a computer to function as each control block of the device (particularly the acquisition unit G1, intersection identification unit G2, and shape information generation unit G3).

[0050] In this case, the device includes a computer having at least one control device (e.g., a processor) and at least one storage device (e.g., a memory) as hardware for executing the program. The control device and storage device execute the program, thereby realizing the functions described in each of the above embodiments.

[0051] The program may be non-transitory and may be recorded on one or more computer-readable recording media. The recording media may or may not be included in the device. In the latter case, the program may be supplied to the device via any wired or wireless transmission medium.

[0052] In addition, some or all of the functions of each of the control blocks can be realized by logic circuits. For example, integrated circuits in which logic circuits that function as each of the control blocks are formed are also included in the scope of the present disclosure. In addition, the functions of each of the control blocks can also be realized by, for example, a quantum computer.

[0053] (Method of manufacturing optical illusion three-dimensional objects) The method for manufacturing an optical illusion three-dimensional object according to the present disclosure may include a step of manufacturing the optical illusion three-dimensional object 1 based on shape information generated by the shape information generating unit G3 of the information processing device 2 described above. For example, the information processing device 2 may be connected to a 3D printer, and the 3D printer may form the optical illusion three-dimensional object 1 according to the shape information. For example, a development diagram of the optical illusion three-dimensional object 1 may be created from the shape information, materials may be processed according to the development diagram, and the processed materials may be assembled. However, the optical illusion three-dimensional object 1 may be manufactured by any manufacturing method.

[0054] (Example) In each of Examples 1 and 2, the inventors used a computer to generate shape information for the optical illusion three-dimensional object 1 from the first perceived shape K1 and the second perceived shape K2, and then used a 3D printer to manufacture the optical illusion three-dimensional object 1 from white resin. The first medium M1 was water, the second medium M2 was air, and the interface BS was the water surface. In both Examples 1 and 2, the actual shape of the manufactured optical illusion three-dimensional object 1 was a three-dimensional shape different from both the first perceived shape K1 and the second perceived shape K2.

[0055] FIG. 7 is a perspective view showing a first perceived shape K1 envisioned by the inventors in Example 1 of the present disclosure. FIG. 8 is a perspective view showing a second perceived shape K2 envisioned by the inventors in Example 1 of the present disclosure. In FIGS. 7 and 8, a grid-patterned xy plane is shown in the background to show perspective. The y direction is the depth direction. As shown in FIG. 7, the first perceived shape K1 was a three-dimensional shape like a part of the side of a cylinder cut away. As shown in FIG. 8, the second perceived shape K2 was a three-dimensional shape like a piece of cardboard with zigzag creases.

[0056] The illusionary three-dimensional object 1 was placed in a container, and water was poured into and drained from the container, and the illusionary three-dimensional object 1 was observed from a given viewpoint VP. Due to the illusion, the observer recognized that the illusionary three-dimensional object 1 had a first perceived shape K1 in the first state when there was no water in the container, and that the illusionary three-dimensional object 1 had a second perceived shape K2 in the second state when the illusionary three-dimensional object 1 was submerged in water.

[0057] 9 shows a photograph of the optical illusion three-dimensional object manufactured in Example 2 of the present disclosure in a first state in which the optical illusion three-dimensional object is in air, and a first perceived shape K1. FIG. 10 shows a photograph of the optical illusion three-dimensional object manufactured in Example 2 of the present disclosure in a second state in which the optical illusion three-dimensional object is in water, and a second perceived shape K2. As shown in FIGS. 9 and 10, the state switching step for switching between the first and second states caused the appearance of the optical illusion three-dimensional object 1 from the same viewpoint VP to switch between the first perceived shape K1 and the second perceived shape K2. The first perceived shape K1 was a three-dimensional shape with an upper surface contour line D reminiscent of a yacht, and the second perceived shape K2 was a three-dimensional shape with an upper surface contour line E reminiscent of a submarine.

[0058] In the first state (see Figures 7 and 9), a bent portion of the contour D in the first perceptual shape K1 becomes a non-bent curved or straight portion of the contour E in the second perceptual shape K2 in the second state (see Figures 8 and 10). Also, in the first state (see Figures 7 and 9), a bent or curved portion of the contour D in the first perceptual shape K1 becomes a bent or curved portion of the contour E in the second perceptual shape K2 in the second state (see Figures 8 and 10).

[0059] [Embodiment 2] Other embodiments of the present disclosure will be described below. For ease of explanation, the same reference numerals will be used to designate components having the same functions as those described in the above embodiment, and the description thereof will not be repeated.

[0060] Fig. 11 is a perspective view showing an optical illusion in an example of an optical illusion three-dimensional object according to the present disclosure. As shown in Fig. 11, in the second state, a first medium M1 may be disposed around the viewpoint VP. In this case, the second direction D2 is the traveling direction of a ray or line of sight traveling outside the first medium M1 when the ray or line of sight traveling within the first medium M1 along the first direction is refracted by an interface BS with the first medium M1 that is located on the opposite side of the intersection point Ri in the first direction D1.

[0061] 〔summary〕 The optical illusion three-dimensional object according to aspect 1 of the present disclosure is an optical illusion three-dimensional object, and in a first state in which no first medium exists between the viewpoint and the optical illusion three-dimensional object, a first perceived shape seen from the viewpoint is different from a second perceived shape seen from the viewpoint through the first medium that causes refraction in a second state in which the first medium exists between the viewpoint and the optical illusion three-dimensional object.

[0062] The optical illusion three-dimensional object according to aspect 2 of the present disclosure may be configured as according to aspect 1, wherein in the first state, some of the curved contour lines in the first perceived shape become non-bent curved or straight contour lines in the second perceived shape in the second state.

[0063] The optical illusion three-dimensional object according to aspect 3 of the present disclosure may be configured as according to aspect 1 or 2, wherein in the first state, a portion of the contour line that is bent or curved in the first perceived shape becomes a contour line that is bent or curved in the opposite direction in the second perceived shape in the second state.

[0064] The optical illusion three-dimensional object according to aspect 4 of the present disclosure may be configured as any one of aspects 1 to 3, wherein in the second state, a second medium is present that causes refraction at the interface with the first medium, the refractive index of the first medium is 1.3 or more and less than 1.35, and the refractive index of the second medium is 1.1 or less.

[0065] The optical illusion three-dimensional object according to aspect 5 of the present disclosure may be configured as any one of aspects 1 to 3, wherein in the second state, a second medium is present that causes refraction at the interface with the first medium, the refractive index of the first medium is 1.35 or more and 2.0 or less, and the refractive index of the second medium is 1.1 or less.

[0066] The optical illusion three-dimensional object according to aspect 6 of the present disclosure may be configured as any one of aspects 1 to 3, wherein in the second state, a second medium is present that causes refraction at the interface with the first medium, and the refractive index of the first medium is 1.3 or more and less than 1.35, and the refractive index of the second medium is 1.35 or more and less than 2.0, or the refractive index of the second medium is 1.3 or more and less than 1.35, and the refractive index of the first medium is 1.35 or more and less than 2.0.

[0067] The optical illusion three-dimensional object according to aspect 7 of the present disclosure may be configured to include an optical illusion three-dimensional object according to any one of aspects 1 to 6, and a state switching unit that switches between the first state and the second state by changing the arrangement of the first medium relative to the optical illusion three-dimensional object.

[0068] An optical illusion three-dimensional object exhibition device according to aspect 8 of the present disclosure may have the configuration according to aspect 7, wherein the first medium is a liquid, and the state switching unit switches from the first state to the second state by placing the liquid between the optical illusion three-dimensional object and the viewpoint or around the optical illusion three-dimensional object.

[0069] A method for displaying an optical illusion three-dimensional object according to aspect 9 of the present disclosure may be a method for displaying an optical illusion three-dimensional object according to any of aspects 1 to 6, and may include a state switching step for switching between the first state and the second state by changing the arrangement of the first medium relative to the optical illusion three-dimensional object.

[0070] An information processing device according to aspect 10 of the present disclosure includes an acquisition unit that acquires, in a first plane, a plurality of first points that constitute a first contour line and a plurality of second points that constitute a second contour line that is different from the first contour line; an intersection point identification unit that identifies, in each of a plurality of second planes that intersect with the first contour line and the second contour line, an intersection point between a straight line passing through the first point and extending in a first direction and a straight line passing through the second point and extending in a second direction; and a shape information generation unit that generates shape information of an optical illusion three-dimensional object whose first perceived shape when viewed from the first direction and whose second perceived shape when viewed from the second direction are different based on the plurality of intersection points identified in the plurality of second planes, wherein the first perceived shape has a shape corresponding to the first contour line and the second perceived shape has a shape corresponding to the second contour line.

[0071] An information processing device according to aspect 11 of the present disclosure may be configured according to aspect 10, wherein the second direction is the direction of travel of a ray of light traveling along the first direction when the ray of light is refracted by a first medium located on the opposite side of the first direction from the intersection point.

[0072] An information processing device according to aspect 12 of the present disclosure may be configured as according to aspect 11, wherein the first perceived shape of the optical illusion three-dimensional object viewed from the first direction in a first state in which the first medium is not present and the second perceived shape of the optical illusion three-dimensional object viewed through the first medium that causes refraction from the first direction in a second state in which the first medium is present are different from each other.

[0073] An information processing device according to a thirteenth aspect of the present disclosure may be configured in the manner according to any one of the tenth to twelfth aspects, wherein the second planes are parallel to one another.

[0074] An information processing device according to a fourteenth aspect of the present disclosure has the configuration according to any one of the tenth to twelfth aspects, and the plurality of second planes may pass through a single viewpoint.

[0075] The method for manufacturing an optical illusion three-dimensional object according to aspect 15 of the present disclosure is a method including a step of manufacturing the optical illusion three-dimensional object based on the shape information generated by the shape information generation unit of the information processing device according to any one of aspects 10 to 14.

[0076] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also included in the technical scope of the present disclosure. [Explanation of symbols]

[0077] 1 Optical illusion three-dimensional object 2. Information processing equipment 3 Exhibition equipment 4. State switching section A First contour line B Second contour line C, D, E Contour lines BS interface F1 1st plane G1 Acquisition Department G2 intersection identification part G3 Shape information generation section K1 First Perceptual Shape K2 Second Perceptual Shape L1_i 1st line of sight L2_i 2nd line of sight M1 First medium M2 Second medium Ni 2nd plane Pi 1st point Qi 2nd point Ri point, intersection VP perspective

Claims

1. An optical illusion three-dimensional object, a first perceived shape seen from a viewpoint in a first state in which a first medium does not exist between the viewpoint and the illusionary three-dimensional object; In a second state in which the first medium exists between the viewpoint and the optical illusion three-dimensional object, the optical illusion three-dimensional object has a second perceived shape that is different from the second perceived shape seen from the viewpoint through the first medium that causes refraction.

2. The optical illusion three-dimensional object according to claim 1, wherein in the first state, a curved portion of the contour line of the first perceived shape becomes a non-bent curved or straight contour line of the second perceived shape in the second state.

3. 2. The optical illusion three-dimensional object according to claim 1, wherein in the first state, a portion of the contour line that is bent or curved in the first perceived shape becomes a contour line that is bent or curved in the opposite direction in the second perceived shape in the second state.

4. In the second state, a second medium exists that causes refraction at an interface with the first medium, The refractive index of the first medium is equal to or greater than 1.3 and less than 1.35, 2. The optical illusion three-dimensional object according to claim 1, wherein the refractive index of the second medium is 1.1 or less.

5. In the second state, a second medium exists that causes refraction at an interface with the first medium, The refractive index of the first medium is 1.35 or more and 2.0 or less, 2. The optical illusion three-dimensional object according to claim 1, wherein the refractive index of the second medium is 1.1 or less.

6. In the second state, a second medium exists that causes refraction at an interface with the first medium, The refractive index of the first medium is 1.3 or more and less than 1.35, and the refractive index of the second medium is 1.35 or more and 2.0 or less, or 2. The optical illusion three-dimensional object according to claim 1, wherein the refractive index of the second medium is 1.3 or more and less than 1.35, and the refractive index of the first medium is 1.35 or more and 2.0 or less.

7. The optical illusion three-dimensional object according to any one of claims 1 to 6, An optical illusion three-dimensional object exhibition device comprising: a state switching unit that switches between the first state and the second state by changing the arrangement of the first medium relative to the optical illusion three-dimensional object.

8. the first medium is a liquid; The optical illusion three-dimensional object exhibition device according to claim 7, wherein the state switching unit switches from the first state to the second state by placing the liquid between the optical illusion three-dimensional object and the viewpoint or around the optical illusion three-dimensional object.

9. A method for displaying the optical illusion three-dimensional object according to any one of claims 1 to 6, comprising: A method for displaying an optical illusion three-dimensional object, comprising a state switching step of switching between the first state and the second state by changing the arrangement of the first medium relative to the optical illusion three-dimensional object.

10. an acquisition unit that acquires, on a first plane, a plurality of first points that form a first contour line and a plurality of second points that form a second contour line that is different from the first contour line; an intersection point specifying unit that specifies an intersection point between a straight line passing through the first point and extending in a first direction and a straight line passing through the second point and extending in a second direction, on each of a plurality of second planes that intersect with the first contour line and the second contour line; a shape information generating unit that generates shape information of an optical illusion three-dimensional object, the first perceived shape seen from the first direction and the second perceived shape seen from the second direction being different, based on the plurality of intersections identified on the plurality of second planes; the first perceived shape has a shape corresponding to the first contour line; An information processing device, wherein the second perceived shape has a shape corresponding to the second contour line.

11. The information processing device according to claim 10 , wherein the second direction is a direction in which a light ray traveling along the first direction is refracted by a first medium that is present on the opposite side of the first direction from the intersection point.

12. the first perceived shape of the illusionary three-dimensional object as viewed from the first direction in a first state in which the first medium does not exist; The information processing device according to claim 11 , wherein in a second state in which the first medium is present, the second perceived shape of the optical illusion three-dimensional object seen through the first medium that causes refraction from the first direction is different from the second perceived shape of the optical illusion three-dimensional object seen through the first medium that causes refraction from the first direction.

13. The information processing device according to claim 10 , wherein the second planes are parallel to each other.

14. The information processing device according to claim 10 , wherein the plurality of second planes pass through a single viewpoint.

15. A method for manufacturing an optical illusion three-dimensional object, comprising the step of manufacturing the optical illusion three-dimensional object based on the shape information generated by the shape information generating unit of the information processing device according to any one of claims 10 to 14.

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