DERIVATION SYSTEM, DERIVATION METHOD, DERIVATION DEVICE, AND DERIVATION PROGRAM

Abstract

A derivation system, a derivation method, a derivation device, and a derivation program are provided that are capable of deriving the state of surfaces inside a building based on the layout of the building. [Solution] The derivation system acquires floor plan information showing the floor plan of a building (steps S1, S4), refers to a model that associates and stores the floor plan, light, and the state of the interior surfaces of the building, and derives the state of the interior surfaces of the building as seen when light is irradiated based on the acquired floor plan information (step S5). Furthermore, the derivation system refers to a database that associates and stores the state of the interior surfaces of the building with the finishing method, and derives the finishing method of the interior surfaces of the building based on the derived state of the interior surfaces of the building (step S6).

Description

[Technical field]

[0001] The present application discloses a derivation system, a derivation method, an acquisition device, and a computer program for deriving a state related to a building. [Background technology]

[0002] In the interior design of buildings, finishing materials such as wallpaper, flooring, and decorative panels are applied to the base surfaces of the building, such as the walls, floors, and ceilings, to improve the design and functionality (see, for example, Patent Document 1). The application of finishing materials can also hide unevenness of the base surface, unevenness of joints, etc. However, it is not easy to select finishing materials such as wallpaper, flooring, and decorative panels to hide unevenness of the base surfaces of the walls, floors, and ceilings. In general, when selecting wallpaper, the person in charge of the construction business and the client discuss the matter and select the wallpaper with an emphasis on price, design, and other factors. However, if the selected finishing material does not match the base surface, unevenness may become apparent after construction, and in that case, additional work such as re-pasting will be required. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2023-033781 A Summary of the Invention [Problem to be solved by the invention]

[0004] One of the factors that can lead to incorrect selection of finishing materials is that depending on the way light hits the surface, such as from oblique sunlight or lighting, unevenness that was not noticeable during construction can become apparent.

[0005] The present application has been made in consideration of the above circumstances, and has as its main object to disclose a derivation system and method for deriving the state of surfaces inside a building, taking into account the layout of the building and the relationship with light.

[0006] Another object of the present application is to provide a derivation device for use in the derivation system disclosed in the present application.

[0007] Furthermore, a further object of the present application is to provide a derivation program for realizing the derivation device disclosed in the present application. [Means for solving the problem]

[0008] In order to solve the above problems, the derivation system disclosed in the present application is a derivation system that uses a derivation device that derives the state of surfaces inside a building, and is characterized in that it includes an acquisition means that acquires floor plan information indicating the layout of a building, and a model that associates and stores the floor plan, light, and the state of surfaces inside the building, and the derivation device includes a state derivation means that refers to the model based on the floor plan information acquired by the acquisition means, and derives the state of the surfaces inside the building that are visible when light is irradiated.

[0009] The derivation system further includes a database that stores the state of the interior surfaces of the building in correspondence with finishing methods, and a finishing derivation means that refers to the database based on the state of the interior surfaces of the building derived by the state derivation means, and derives a finishing method for the interior surfaces of the building.

[0010] In addition, in the derivation system, the interior surfaces of the building include at least one of a wall surface, a floor surface, and a ceiling surface, and the finishing method includes at least one element of a finishing material covering the surface, a finishing craftsman, and a number of days for finishing.

[0011] In addition, in the derivation system, the surface inside the building is a wall surface, the condition of the surface inside the building is the unevenness of the wall surface, and the finishing method is characterized in that it includes a process of selecting wallpaper to cover the surface based on a plurality of classified classes.

[0012] In the above deriving system, the acquisition means is characterized in that it acquires the floor plan information as image information by capturing an image of a floor plan showing the floor plan with an imaging unit that captures an image of an object.

[0013] Furthermore, the derivation method disclosed in the present application is a derivation method using a derivation device that derives the state of surfaces inside a building, and is characterized in that it acquires floor plan information indicating the layout of the building, refers to a model that correlates and stores the floor plan, light, and the state of surfaces inside the building, and derives the state of the surfaces inside the building that are visible when light is illuminated based on the acquired floor plan information.

[0014] Furthermore, the acquisition device disclosed in the present application is characterized by comprising a means for acquiring floor plan information indicating the layout of a building, a means for accessing a model that correlates and stores the floor plan, light, and the state of the surfaces inside the building, and a means for referring to the model based on the floor plan information and deriving the state of the surfaces inside the building as viewed when light is irradiated.

[0015] Furthermore, the derivation program disclosed in the present application is characterized in that it causes a computer to execute a step of accessing a model that stores a correlation between floor plan, light, and the state of surfaces inside a building, and referring to the model based on floor plan information that indicates the floor plan of the building, to derive the state of the surfaces inside the building that are visible when light is irradiated. Effect of the Invention

[0016] The derivation system etc. disclosed in the present application derives the state of the surface inside the building that is visually recognized in a state where light is irradiated, based on the acquired floor plan information. As a result, the derivation system etc. disclosed in the present application has excellent effects such as being able to derive the state of the surface inside the building taking into account the lighting conditions. [Brief description of the drawings]

[0017] [Figure 1] 1 is an explanatory diagram conceptually illustrating an example of a system configuration of a derivation system disclosed in the present application. [Diagram 2] 2 is a block diagram showing an example configuration of various devices used in the derivation system disclosed in the present application. FIG. [Diagram 3] 2 is a block diagram showing an example configuration of various devices used in the derivation system disclosed in the present application. FIG. [Figure 4] 11 is a flowchart illustrating an example of a derivation process of a derivation device and an acquisition device included in the derivation system disclosed in the present application. [Diagram 5] 1 is an explanatory diagram showing an example of an image displayed on a display unit of an acquisition device included in a derivation system disclosed in the present application. FIG. [Figure 6] 1 is an explanatory diagram showing an example of an image displayed on a display unit of an acquisition device included in a derivation system disclosed in the present application. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0018] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The following embodiments of the present invention will be described in detail. Note that the following embodiments are merely examples of the present invention and are not intended to limit the technical scope of the present invention.

[0019] <Application Examples> The derivation system disclosed in the present application derives the condition of the surfaces inside a building, such as floors, walls, and ceilings, for example, the condition of unevenness such as unevenness and joints. The derivation system disclosed in the present application is used to select finishing methods, such as finishing materials such as flooring, wallpaper, and decorative panels to cover the surfaces, and finishing craftsmen, for the base surfaces such as floors, walls, and ceilings. Below, with reference to the drawings, a derivation system using the derivation device 1 shown in the drawings will be described as an example.

[0020] <System configuration> FIG. 1 is an explanatory diagram conceptually illustrating an example of a system configuration of the derivation system disclosed in the present application. The derivation system disclosed in the present application is realized by using a derivation device 1, and various devices such as an inference device 2, a storage device 3, and an acquisition device 4 that can communicate with the derivation device 1. The derivation device 1 is a device using a computer such as a server computer, and is connected to a communication network NW such as a LAN (Local Area Network), a WAN (Wide Area Network), a dedicated communication network, or the Internet. The inference device 2 is a device using a computer such as an inference server computer, and is communicatively connected to the communication network NW. The storage device 3 is a device using a computer such as a database server computer, and is communicatively connected to the communication network NW. The acquisition device 4 is a device used by users such as employees belonging to a construction-related business entity and owners who are considering designs related to buildings. The acquisition device 4 is a device using a computer such as a personal computer, a tablet computer, or a highly functional mobile phone (a so-called smartphone), and is capable of communicating via the communication network NW. The derivation system disclosed in the present application illustrated in FIG. 1 shows an example of implementation as a system in which an acquisition device 4 captures an image of a floor plan showing the layout of a building, and displays candidate wallpapers suitable for a wall surface using AI (Artificial Intelligence) that uses a learning model.

[0021] <Hardware configuration of the device> Next, the configuration of various devices used in the derivation system disclosed in the present application will be described. Fig. 2 is a block diagram showing an example of the configuration of various devices used in the derivation system disclosed in the present application. Fig. 2 mainly shows an example of the configuration of a derivation device 1, an inference device 2, and a storage device 3. The derivation device 1 includes various components such as a control unit 10, a storage unit 11, and a communication unit 12.

[0022] The control unit 10 is a processor such as a CPU (Central Processing Unit) that executes processes for controlling the entire device, and includes various circuits such as an information processing circuit, a timer circuit, and a register circuit.

[0023] The storage unit 11 is a storage unit configured using non-volatile memories such as a hard disk, an SSD (Solid State Drive), a RAID (Redundant Arrays of Inexpensive Disks), and a flash memory, and volatile memories such as various RAMs (Random Access Memories). The storage unit 11 stores computer programs such as a basic program (OS: Operating System) and an application program (application program) that runs on the basic program. As one of the application programs, the storage unit 11 stores a derivation program 110 for realizing the derivation device 1.

[0024] The communication unit 12 is a communication unit such as a LAN port, and is connected to the communication network NW via a communication device such as a router or a gateway, and is capable of communicating with various devices via the communication network NW.

[0025] A computer such as a server computer configured as described above operates as a derivation device 1 by reading programs such as the derivation program 110 stored in the memory unit 11 under the control of the control unit 10 and executing various steps contained in the various programs.

[0026] The inference device 2 includes various components such as a control unit 20, a storage unit 21, and a communication unit 22. The storage unit 21 of the inference device 2 stores various programs and data such as a trained model 210, an inference API (Application Programming Interface) for using the trained model 210, and various libraries for inference. The trained model 210 is a model obtained by a learning method such as supervised learning, and stores information such as various parameters that associate the layout and light of a building with the state of the surface inside the building. The trained model 210 is generated, for example, by forming unevenness simulating unevenness on a surface material, irradiating light of various wavelengths from various directions, and learning the state of the surface as viewed from various directions. In addition, for example, the trained model 210 is generated by irradiating various lights such as natural light and artificial light from various directions to surfaces such as walls, floors, and ceilings of a building such as a model house, an experimental house, and an actual building, and learning the state of the surface as viewed from various angles. The state of the surface that is the objective variable is treated as a level classified into multiple stages.

[0027] The storage device 3 includes various components such as a control unit 30, a storage unit 31, and a communication unit 32. The storage unit 31 of the storage device 3 stores a database 310 that stores various data such as buildings and finishing methods. The finishing method includes elements such as the finishing material that covers the surface, the finishing craftsman who performs the finishing work using the finishing material, and the number of days required for the finishing work by the finishing craftsman. The finishing materials included in the finishing method are stored by classifying the finishing material information indicating the finishing material that covers the surface, such as wallpaper that covers the wall surface, flooring material that covers the floor surface, and decorative board that covers the ceiling surface, into multiple levels. The finishing materials indicated by the finishing material information are classified into classes that can correspond to the level of unevenness of the surface. Specifically, the class that can hide the unevenness for each level is the applicable class. For example, for a surface with large unevenness, a finishing material using a thick material is classified as the applicable class. The finishing craftsmen included in the finishing method are stored as craftsman information indicating the craftsmen classified according to their skills in finishing work, for example. The number of days for finishing included in the finishing method indicates the relationship between the unevenness level of the surface and the finisher, and is stored as information on the number of days required for a certain level of craftsman to perform finishing work on a surface with a certain level of unevenness.

[0028] The derivation device 1 can access the inference device 2 and the storage device 3 and use the trained model 210 of the inference device 2 and the database 310 of the storage device 3.

[0029] Fig. 3 is a block diagram showing an example of the configuration of various devices used in the derivation system disclosed in the present application. Fig. 3 mainly shows an example of the configuration of the acquisition device 4. Fig. 3 shows an example of the configuration of the acquisition device 4 using a computer such as a tablet computer. The acquisition device 4 includes various components such as a control unit 40, a storage unit 41, a display unit 42, an operation unit 43, an imaging unit 44, a position acquisition unit 45, a direction acquisition unit 46, and a communication unit 47. The control unit 40 is a processor. The storage unit 41 is a storage unit that stores information such as various programs and data.

[0030] The display unit 42 is an output interface for displaying images such as a liquid crystal monitor. The operation unit 43 is an input interface for receiving operation inputs such as a touch panel and a keyboard. The display unit 42 and the operation unit 43 can also be configured as a liquid crystal touch panel in which the liquid crystal monitor and the touch panel are superimposed and integrated. The imaging unit 44 is an input interface used for inputting light from a camera or the like using an imaging element, and generates image information such as still images and videos by capturing images.

[0031] The position acquisition unit 45 is a position sensor that has an antenna for communicating with artificial satellites such as GNSS (Global Navigation Satellite System) satellites, and acquires and processes position information indicating the position of the acquisition device 4 based on communication with the GNSS satellite. The direction acquisition unit 46 is a direction sensor that uses sensors such as an acceleration sensor, a gyro sensor, and a magnetic sensor to detect the direction in which the acquisition device 4 is heading, for example, the elevation angle and direction in which the imaging unit 44 captures an image. The communication unit 47 is a communication unit such as an antenna and an auxiliary device, and is connected to the communication network NW via a wireless communication network.

[0032] <Device software processing> Next, the processing of various devices used in the derivation system disclosed in the present application will be described. FIG. 4 is a flowchart showing an example of the derivation processing of the derivation device 1 and the acquisition device 4 included in the derivation system disclosed in the present application. The user operates the acquisition device 4 to perform an operation to acquire the floor plan of the building. For example, in the case of a tablet computer illustrated in FIG. 3, the user performs an operation to capture an image of a floor plan showing the floor plan of the target building. The floor plan includes information that can be used to infer the direction, the positions and sizes of doors and windows, the type and installation position of lighting, the situation of surrounding buildings, and the type and irradiation direction of light, in addition to the floor plan of the building showing the positions of surfaces such as walls. The acquisition device 4 that has received the operation executes the derivation processing under the control of the control unit 40.

[0033] The control unit 40 of the acquisition device 4 captures an image of a floor plan showing a floor plan with the imaging unit 44 (step S1), generates image information such as a still image based on the captured image, and acquires the floor plan information as the image information (step S2). The floor plan information acquired in step S2 may be image information such as a still image or a video image obtained by capturing an image of the interior of an actual building. When using image information of an actual interior of a building, the acquisition device 4 generates the floor plan information by adding information such as the image capture date and time, the position acquired by the position acquisition unit 45, and the direction acquired by the direction acquisition unit 46 to the image information. When the acquisition device 4 is configured using a desktop personal computer, the acquisition of the floor plan information may be a process such as reading an image using a reading device such as a scanner, or reading the floor plan information from another device or a storage medium such as a semiconductor memory. When the floor plan information is read from another device or storage medium, the floor plan information is not limited to image information, and may be information capable of reproducing the floor plan, such as CAD data, data for a 3D printer, etc.

[0034] The control unit 40 of the acquisition device 4 transmits the acquired floor plan information to the derivation device 1 via the communication network NW through the communication unit 47 (step S3).

[0035] The derivation device 1 executes the derivation process exemplified below by reading various programs such as the derivation program 110 stored in the storage unit 11 and executing steps included in the various programs under the control of the control unit 10. The control unit 10 of the derivation device 1 receives the floor plan information transmitted from the acquisition device 4 via the communication unit 12, thereby acquiring the floor plan information (step S4).

[0036] The control unit 10 accesses the inference device 2, and based on the acquired floor plan information, derives the state of the surface inside the building that is visually recognized when light is irradiated, referring to the trained model 210 (step S5). The derivation of the surface state in step S5 is a process of deriving the state of the surface of the wall, floor, ceiling, etc. inside the building from the floor plan information by AI processing referring to the trained model 210. The surface state is derived as a level in which the unevenness of the surface is classified into multiple stages. Note that, when natural light is irradiated from the outside, the state to be recognized changes depending on the season and time, and when artificial light is irradiated, the state changes depending on the type of light irradiated from which lighting. The state to be recognized also changes depending on the viewing direction. Therefore, in step S5, the derivation device 1 derives the state of the surface according to the situation in which the unevenness is most clearly visible.

[0037] The control unit 10 accesses the storage device 3, and based on the derived state of the surface inside the building, refers to the database 310 and derives a finishing method for the surface inside the building (step 6). In the derivation of the finishing method in step S6, a finishing material of a grade that can hide unevenness is derived according to the level of the surface state derived in step S5, and further, a finisher of a grade according to the level and the number of days required for the finishing work by that craftsman are derived. The derived finishing method is derived as a list of applicable finishing materials and finishers. For example, for a surface of level 1 with small unevenness, a finishing material of grade 1 or higher with low concealing properties using a thin material is selected from among a plurality of classified finishing materials, and for a surface of level 3 with large unevenness, a finishing material of grade 3 or higher with high concealing properties is selected. In addition, the larger the unevenness is or the lower the concealing property of the finishing material selected, the higher the grade of the finisher is required. Furthermore, when the level of the wall, the grade of the finishing material, and the grade of the finisher are determined, the number of days is derived from the relationship between them. The finishing method may be derived as a selection list combined with the surface condition, or, for example, selection options for finishing materials and selection options for craftsmen may be output in sequence, and the next finishing method may be derived and presented depending on the selection.

[0038] The control unit 10 transmits the status information indicating the surface status derived in step S5, and the finishing information such as finishing material information indicating the finishing material, craftsman information indicating the finishing craftsman, and number of days information indicating the number of days for finishing derived in step S6 from the communication unit 12 to the acquisition device 4 via the communication network NW (step S7).

[0039] The control unit 40 of the acquisition device 4 receives the status information and the finishing information through the communication unit 47 (step S8), and displays the received status information and the finishing information on the display unit 42 (step S9). The status information and the finishing information in step S9 are displayed so that the surfaces inside the building, the surface conditions, and the finishing information can be visually recognized in association with each other. The surface conditions and the finishing information may be displayed as a list in association with the information indicating the surfaces inside the building, or may be displayed in association with the layout information so that the information can be intuitively recognized. In addition, when displaying the finishing information, the user inputs the surface and the finishing material, and the acquisition device 4 that receives the input judges whether or not it is appropriate to use the selected finishing material on the selected surface, and if the finishing material is suitable, a list of other finishing information such as craftsman information, number of days information, etc. may be displayed.

[0040] 5 and 6 are explanatory diagrams showing an example of an image displayed on the display unit 42 of the acquisition device 4 included in the derivation system disclosed in the present application. FIG. 5 is an image showing floor plan information acquired by the acquisition device 4, and FIG. 6 is an image showing a state in which surface conditions and finishing information are superimposed on the floor plan. The acquisition device 4 displays the image shown in FIG. 5 by acquiring floor plan information. FIG. 6 shows an image in a state in which the user performs an operation to specify surfaces such as walls, floors, and ceilings shown in the floor plan from the state shown in FIG. 5. As shown in FIG. 6, when the user performs an operation to specify a specific surface, the surface condition based on the state information corresponding to the specified surface and a list of finishing materials such as wallpaper based on the finishing information are displayed. Furthermore, when the user performs an operation to specify a finishing material from the list of finishing materials, a list of craftsmen according to the grade of the specified finishing material is displayed. Furthermore, when the user performs an operation to specify a craftsman from the list of craftsmen, the number of days required for work is displayed. When displaying the finishing material information, craftsman information, and number of days information as the finishing information, the acquisition device 4 displays various pieces of information based on the selection list received from the derivation device 1, but may access the derivation device 1 and display information each time a designation is received from the user. Also, when the user is the client, the acquisition device 4 may display only the finishing information without displaying the surface condition.

[0041] In the above manner, the derivation device 1 and the acquisition device 4 included in the derivation system disclosed in the present application execute the derivation process.

[0042] As described above, the derivation system disclosed in the present application derives the state of unevenness, etc., of surfaces such as walls, floors, and ceilings that are visually recognized in a state where light is irradiated, based on the layout of the building. The state is derived using a model such as a trained model 210 that is generated in advance by a learning method such as supervised learning based on the results of experiments, actual measurements, etc. Furthermore, the derivation system derives finishing information such as finishing materials selected according to the state of the surface from among a plurality of finishing materials such as wallpaper, flooring, and decorative panels. As a result, the derivation system disclosed in the present application has excellent effects such as being able to present the state of the building surfaces based on the layout of the building, and further being able to present finishing information such as finishing materials appropriate for each surface.

[0043] Furthermore, the derivation system disclosed in the present application can also present information on the finishing craftsman, number of work days, etc., as the finishing method. Moreover, the derivation system disclosed in the present application has an excellent effect of providing a user interface that allows intuitive understanding of the condition by displaying the surface condition and finishing information superimposed on the floor plan.

[0044] The present invention is not limited to the above-described embodiment, and can be implemented in various other forms. Therefore, the embodiment is merely illustrative in all respects and should not be interpreted as being limited. The scope of the present invention is indicated by the claims, and is not restricted in any way by the text of the specification. Furthermore, all modifications and changes within the equivalent scope of the claims are within the scope of the present invention.

[0045] For example, in the above embodiment, a derivation system using the derivation device 1, the inference device 2, the storage device 3, and the acquisition device 4 is exemplified, but the derivation system disclosed in the present application is not limited to this and can have various system configurations. For example, the derivation system disclosed in the present application can be realized in various configurations, such as configuring the acquisition device 4 and the derivation device 1 in one device, and further adding some or all of the functions of the inference device 2 and the storage device 3 to that device. Also, for example, the derivation system disclosed in the present application can be configured with multiple devices linked to the acquisition device 4.

[0046] Also, for example, in the above embodiment, an inference form using AI is shown, but the derivation system disclosed in the present application is not limited to this, and can be deployed in various forms as long as a model that associates and stores the floor plan and light with the surface condition inside the building is used. For example, the derivation system disclosed in the present application can be deployed in various forms, such as by using a model based on the results of multivariate analysis in which information on the floor plan and light, which are explanatory variables, is quantified as explanatory variables, and the surface condition is quantified as a target variable. [Explanation of symbols]

[0047] 1 Derivation device 10 Control section 11 Storage section 110 Derivation Program 12 Communications Department 2 Reasoning device 20 Control section 21 Memory section 210 trained models 22 Communications Department 3 Storage device 30 Control section 31 Storage section 310 Database 32 Communications Department 4 Acquisition device 40 Control section 41 Storage section 42 Display section 43 Operation section 44 Imaging unit 45 Position acquisition unit 46 Direction Acquisition Department 47 Ministry of Communications NW Communications Network

Claims

1. A derivation system using a derivation device that derives a state of a surface inside a building, An acquisition means for acquiring floor plan information indicating a floor plan of a building; A model that associates and stores the layout and lighting with the condition of the base surface on which the interior finishing materials are applied. Equipped with The delivery device is A state deriving means is provided for deriving a state of a base surface on which a finishing material is to be attached inside the building, the state being visually recognized in a state where light is irradiated, based on the floor plan information acquired by the acquiring means, with reference to the model. A derivation system comprising:

2. The derivation system of claim 1, The method further includes a database that stores the state of a base surface to which a finishing material is applied inside the building in association with a finishing method, A finishing deriving means is provided for deriving a finishing method for a base surface to which a finishing material inside the building is to be applied, by referring to the database based on the state of the base surface to which the finishing material inside the building is to be applied, derived by the state deriving means. A derivation system comprising:

3. The derivation system according to claim 2, The base surface to which the interior finishing material of the building is applied includes at least one of a wall surface, a floor surface, and a ceiling surface, The finishing method includes at least one element of a finishing material that covers a base surface to which the finishing material is applied, a finishing craftsman, and a number of days for finishing. A derivation system comprising:

4. The derivation system according to claim 2, The base surface to which the interior finishing material of the building is applied is a wall surface, The condition of the interior surface of the building is uneven on the wall. The finishing method includes a process of selecting wallpaper to cover a base surface on which a finishing material is to be applied, based on a plurality of classified classes. A derivation system comprising:

5. A derivation system according to any one of claims 1 to 4, The acquisition means includes: The imaging unit captures an image of a floor plan showing the floor plan, thereby acquiring the floor plan information as image information. A derivation system comprising:

6. A method for deriving a state of an interior surface of a building using a deriving device, comprising: Obtain floor plan information showing the layout of the building, A model is referenced that associates and stores the floor plan, light, and the state of the base surface on which the interior finishing material is to be attached, and the state of the base surface on which the interior finishing material is to be attached, as viewed when light is irradiated, is derived based on the acquired floor plan information. A method for deriving the above-mentioned

7. A means for acquiring floor plan information indicating a floor plan of a building; A means for accessing a model that correlates and stores the layout and light with the condition of the base surface on which the interior finishing material is to be applied; A means for deriving the state of a base surface on which a finishing material is to be attached inside a building, the state being visually recognized when light is irradiated, based on floor plan information and referring to the model; A derivation device comprising:

8. On the computer, Accessing a model that correlates and stores the layout and lighting with the condition of the base surface on which the interior finishing materials will be applied; Executing a step of deriving the state of a base surface on which a finishing material is to be attached inside the building, which is visually recognized in a state where light is irradiated, by referring to the model based on floor plan information indicating the floor plan of the building. A derivation program characterized by:

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