JP5950342B2 - Projected area calculation program - Google Patents

Description

  The present invention relates to a projected area calculation program for calculating a parallel projected area used for calculating a form factor.

  Conventionally, in a simulation of radiant heat transfer or illuminance, or a simulation of visibility of an object or space, an evaluation object such as a building, a person, and an industrial product and a form factor of a surrounding surface are used. The parallel projection area and effective radiation area for calculating the form factor are calculated by taking photographs of a real object or model having the same shape as the target model from various directions (see, for example, Non-Patent Document 1).

  There is also known a method of calculating a heat input amount by dividing a three-dimensional figure to be analyzed into a plurality of surface elements and using a form factor calculated based on a perspective projection area of each surface element (for example, (See Patent Document 1).

JP 2007-164667 A

By Masayuki Oguro (M.Oguro), Edward Allens (E. Arens), H. Zhang, Kazuyo Tsuzuki (T. Katayama), Tadahisa Katayama Measurement of projected area factors for thermal radiation analysis on each part of the human body ”, Architectural Institute of Japan, 2001, No. 547, pp.17-25

  However, conventionally, in order to calculate the parallel projection area and the effective radiation area, it has been necessary to photograph a real object or a model having the same shape as the target model from various directions, so that there is a problem that it takes a long time. In particular, it takes a lot of labor and time to correct the target model according to the result of calculating the parallel projection area and calculate the parallel projection area of the corrected target model.

  Furthermore, it is difficult to calculate the parallel projection area with high accuracy. For example, when the model of the target model is used, the model may not be created according to the design drawing of the target model, so that the parallel projection area with respect to the shape of the target model cannot be calculated with high accuracy. Moreover, since it is necessary to take a photograph within a limited distance, it is impossible to calculate a parallel projection area when the target model is viewed from infinity.

  In addition, when calculating the heat input using the form factor calculated based on the conventional perspective projection area, a space (for example, a room) in which radiation calculation is performed and a target (for example, a human) for calculating the heat input are determined. It was necessary to model with an integral three-dimensional shape. Therefore, it is necessary to create a three-dimensional shape model that is integrated with the room model each time a person's orientation or standing position is changed.

  Therefore, the present invention has been made in view of these points, and a projection area calculation program for causing a computer to calculate a parallel projection area corresponding to a plurality of directions in a short time with high accuracy and to store it in a storage medium. The purpose is to provide.

  In order to solve the above-described problems, in the present invention, a step of acquiring a plurality of projection images obtained by projecting a shape model having a plurality of parts from a plurality of directions on a computer, and a plurality of projections corresponding to the plurality of directions Projection for executing a step of calculating a plurality of parallel projection areas of a plurality of parts based on an image and a step of storing a plurality of parallel projection areas of each of the plurality of parts in association with a plurality of directions An area calculation program is provided.

  Further, the above projected area calculation program causes the computer to calculate a solid angle based on at least one of the number of azimuths and the interval between the azimuths, and the parallel projected area corresponding to each of the azimuths. The step of calculating the effective radiation area by multiplying the result of multiplying the solid angle by and the step of storing the effective radiation area in association with the parallel projection area may be further executed.

  Further, the projected area calculation program calculates a boundary position of a plurality of parts based on at least one of an angle of a plurality of surface elements in contact with each other in the shape model and a density of the plurality of surface elements in the shape model. Further steps may be executed.

  In the step of obtaining a plurality of projection images, the projection area calculation program obtains a plurality of projection images including an obstacle model that overlaps at least a partial region of the shape model when viewed from at least one orientation, In the step of calculating a plurality of parallel projection areas, the plurality of parallel projection areas may be calculated based on an image of a region excluding a region overlapping the obstacle model among the plurality of projection images.

  According to the present invention, there is an effect that parallel projection areas corresponding to a plurality of directions can be calculated with high accuracy in a short time and stored in a storage medium.

An example of the flowchart of the projection area calculation program of the reference example of this invention is shown. An example of a plurality of projection images obtained by projecting a human body shape model from a plurality of directions is shown. An example of a plurality of projection images obtained by projecting a human body shape model from a plurality of directions is shown. An example of a plurality of projection images obtained by projecting a human body shape model from a plurality of directions is shown. An example of the projection image of the shape model of a building is shown. The relationship between a shape model and a plurality of directions is shown. An example of a parallel projection area is shown. An example of a parallel projection area of a specific part corresponding to a plurality of altitude angles α and a plurality of azimuth angles β is shown. An example of the flowchart of the projection area calculation program of 1st Embodiment is shown. An example of a method for calculating a form factor, an effective radiation area, and a solid angle will be described. An example of the calculation method of the boundary position of the site | part of a shape model is shown. An example of a state where there is an obstacle in the vicinity of the shape model is shown.

< Reference Example of the Present Invention >
[Configuration example of projected area calculation program]
FIG. 1 shows an example of a flowchart of a projected area calculation program according to a reference example of the present invention . The projection area calculation program of this reference example causes a computer to execute a step of acquiring a projection image (S110), a step of calculating a parallel projection area (S120), and a step of storing a parallel projection area (S130). For example, the projection area calculation program is stored in a storage medium such as a computer-readable memory and a CD-ROM. The projection area calculation program may be downloaded to a computer via a network.

  In the step of acquiring a projection image (S110), the computer acquires a plurality of projection images obtained by projecting a shape model having a plurality of parts from a plurality of directions. For example, the computer acquires an image indicating a shape of a building, a person, an industrial product, or the like viewed from a plurality of directions as a projection image. The projected image is an image expressed by, for example, computer graphics.

  The computer may acquire a projection image generated by a program (for example, computer graphics generation software) other than the projection area calculation program, or may acquire a projection image generated by the projection area calculation program. In addition, a computer that executes the projection area calculation program may acquire a projection image generated by another computer.

  2A, 2B, and 2C show an example of a plurality of projected images obtained by projecting a human body shape model from a plurality of directions. FIG. 2D shows an example of a projected image of a building shape model. FIG. 3 shows the relationship between the shape model and a plurality of directions.

  FIG. 2A shows an image when a human body is projected from the front (altitude angle α = 0 °, azimuth angle β = 0 °). FIG. 2B shows an image when the human body is projected from an oblique direction (altitude angle α = 45 °, azimuth angle β = 45 °). FIG. 2C shows an image when the human body is projected from above (altitude angle α = 90 °, azimuth angle β = 0 °).

  The projection image may have a plurality of parts corresponding to the plurality of parts of the shape model. Specifically, the projected images shown in FIGS. 2A, 2B and 2C are the head, neck, upper right arm, left upper arm, right arm, left arm, right hand, left hand, chest, abdomen, back, right thigh, left thigh, right Each has a shin, left shin, right foot, and left foot. The projected image of the building shown in FIG. 2D has parts of a first floor part, a second floor part, and a third floor part. The projection image may have a single part. For example, when the shape model is a human body, the projected image may be an image obtained by projecting the whole body.

  Next, the step of calculating the parallel projection area (S120) will be described. In the step of calculating a parallel projection area (S120), the computer calculates a plurality of parallel projection areas of a plurality of parts based on a plurality of projection images corresponding to a plurality of directions. Here, the parallel projection area of the part X calculated based on the projection image corresponding to the azimuth a indicates a size that allows the part X of the shape model to be viewed from infinity of the azimuth a.

FIG. 4 shows an example of a parallel projection area. FIG. 4 shows the parallel projection area A _p1 of the right shin with respect to the azimuth a, and the parallel projection area A _p2 of the right shin with respect to the azimuth b. As is clear from FIG. 4, the parallel projection area of the selected part varies depending on the direction in which the selected part is projected. For example, parallel projection area A _p1 of the right shin against azimuth a is greater than parallel projection area A _p2 of the right shin against azimuth b.

  The computer selects a projection image corresponding to the azimuth selected from the plurality of azimuths, and calculates the image area of the part selected from the plurality of parts included in the selected projection image as a parallel projection area for the selected part. The computer may calculate a parallel projection area of each of a plurality of portions of the shape model for each combination of a plurality of azimuth angles and altitude angles.

  The computer may automatically change at least one of the form, orientation, and position of the shape model, and calculate the parallel projection area for each predetermined change amount. For example, when the shape model is a human body, the computer changes a plurality of postures when a person is walking and moving, a walking direction, a position every predetermined time (for example, 0.5 seconds), and the like. A shape model is generated, and a parallel projection area for each shape model is calculated. By doing in this way, the computer can construct a database in which parallel projection areas for various states of the shape model are stored.

  When the projection image acquired by the computer is an image generated by computer graphics generation software, the projection image shows a shape model when the shape model is viewed from strictly at infinity. Therefore, the computer can calculate the parallel projection area of the shape model when viewed from infinity strictly with high accuracy by calculating the parallel projection area using the projection image generated by the computer graphics generation software. it can.

  Subsequently, in the step of storing the parallel projection area (S130), the computer stores the plurality of parallel projection areas of each of the plurality of parts in association with the plurality of directions. For example, for each of a plurality of parts included in the shape model, the computer calculates the parallel projected areas of the plurality of parts at addresses of a storage medium such as a memory corresponding to a combination of a plurality of azimuth angles and a plurality of altitude angles. Remember.

  FIG. 5 shows an example of a parallel projection area of a specific part corresponding to a plurality of altitude angles α and a plurality of azimuth angles β. In the example shown in FIG. 5, the computer stores the parallel projection area in each of a plurality of directions determined by the combination of the altitude angle α at intervals of 30 ° and the azimuth angle β at intervals of 15 ° in the storage medium. The computer may store the parallel projection area for each combination of altitude angle α and azimuth angle β at arbitrary intervals.

  The projection area calculation program may cause the computer to further execute a step of generating a plurality of directions used for calculating the parallel projection area. For example, the computer acquires the number of directions used for calculating the parallel projection area, and determines a plurality of directions based on the acquired number.

  The computer may determine the order of the directions for calculating the parallel projection area. The computer may calculate the parallel projection areas in the order of orientations determined according to the shape of the target shape model for calculating the parallel projection areas. As an example, the computer calculates the parallel projection area by sequentially changing the azimuth angle β with the altitude angle α selected, and then sequentially changes the azimuth angle β with the next altitude angle α selected. Calculate the area.

  The computer may calculate the parallel projection area in a different number of directions for each part. For example, the computer determines the number of azimuths for calculating the parallel projection area in each part according to the accuracy required for the view factor specified for each part by the user. The computer may calculate the parallel projection area in a larger number of directions as the accuracy required for the form factor is higher. By determining the number of orientations for which the computer calculates the parallel projection area for each part, the calculation time of the part that does not require high accuracy and the capacity of the storage medium that stores the parallel projection area can be reduced. it can.

  Furthermore, the computer may change at least one of the number of azimuths and the azimuth intervals for calculating the parallel projection area based on the shape model, the shape of the region in the shape model, or the region in the region. For example, the computer calculates a parallel projection area with a first azimuth interval on the face side and calculates a parallel projection area with a second azimuth interval coarser than the first azimuth interval on the back side.

  The computer calculates at least one of the number of azimuths and the azimuth interval for calculating the parallel projection area based on the distance model and the positional relationship with the shape model, the part in the shape model, or another shape model around the region in the part. May be changed. For example, the computer can calculate the shape factor of the portion in contact with the wall surface or the floor surface with high accuracy by reducing the azimuth interval when the wall surface or the floor surface is in the vicinity of a specific portion in the shape model. . The computer calculates the parallel projection area with the optimum number of azimuths and azimuth intervals according to the shape model, the shape of the part in the shape model or the region in the part, etc., thereby reducing the calculation time and the capacity of the storage medium be able to.

As described above, according to the projection area calculation program according to this reference example , the computer calculates the parallel projection area when the shape model is viewed from infinity strictly in an arbitrary direction with high accuracy, and the calculated parallel projection. The area can be stored in the storage medium in association with the orientation. Therefore, it is possible to create a database of parallel projection areas calculated by changing various conditions flexibly without taking time to take a photograph of the shape model.

<First embodiment>
[Remember effective radiation area]
Figure 6 shows an example of a flowchart of a projected area calculation program of the first embodiment. The projected area calculation program of the present embodiment causes the computer to further execute a step of calculating a solid angle (S140), a step of calculating an effective radiation area (S150), and a step of storing the effective radiation area (S160). Thus, it differs from the projected area calculation program of the reference example of the present invention . The effective radiation area is an area obtained by accumulating parallel projection areas for all orientations, and is used for calculating a form factor. Details of the effective radiation area calculation method will be described later.

  In the step of calculating the solid angle (S140), the computer calculates the solid angle based on at least one of the number of the plurality of directions and the interval between the plurality of directions. Here, the solid angle is expressed as a function of the area of a region delimited by a conical surface formed by a plurality of half straight lines coming out from the center of a target portion for calculating an effective radiation area.

  In the step of calculating the effective radiation area (S150), the computer calculates the effective radiation area by adding up the result of multiplying the parallel projection area corresponding to each of the plurality of orientations by the solid angle. In the step of storing the effective radiation area (S160), the computer stores the effective radiation area in association with the parallel projection area. The computer may calculate the shape factor of the shape model using the effective radiation area.

FIG. 7 shows an example of a method for calculating the form factor, the effective radiation area, and the solid angle. In FIG. 7, the shape model of the human body is provided on a sphere S having a radius R centered on the center point of the head having the surface A. Area on the surface of the sphere S is shown a surface B of A _B. The plane B has been shown microfacet ΔB area dA _B. The angle between the normal direction of the center position of the minute surface ΔB and the direction of the line segment connecting the minute surface ΔB and the surface A is θ.

In FIG. 7, when the surface B is the surface of the entire sphere S, the form factor F _AB of the surface A relative to the surface B can be calculated by integrating the small surface ΔB and the form factor of the surface A over the entire sphere S. . That is, assuming that the parallel projection area viewed from the minute surface ΔB is A _p and the effective radiation area is A _eff , F _AB is calculated by the following equation (1).

Since the surface B is the entire sphere S, F _AB = 1, and if the radius R is sufficiently large, cos θ≈1, so the effective radiation area A _eff is expressed by the following equation (2).

Here, the solid angle dω _B of the minute surface ΔB on the sphere S is expressed by the following equation (3).

Therefore, the effective radiation area A _eff is calculated by the following equation (4).

The computer may store the effective radiation area calculated by the above equation (4) in a storage medium in association with the parallel projection area. Furthermore, the computer may calculate the form factor F _AB of the surface A with respect to the minute surface ΔB by the following equation (5) based on the parallel projection area and the effective radiation area stored in the storage medium.

In the step of calculating a solid angle (S140), the computer may calculate the solid angle based on the number of a plurality of directions used for calculating the effective radiation area, or calculate the solid angle based on the interval between the plurality of directions. May be. For example, the effective number of orientations to be used for calculation of the radiation area 18 (advanced angle direction to 3, 6 in the azimuthal direction) if it is, the azimuth angle _{^{dω B = 4πR 2/18 /}} R 2 = 2π / 9 Is calculated.

  The computer may determine the number of azimuths or the azimuth interval used for calculating the effective radiation area according to the accuracy required for the form factor designated by the user. The computer can calculate the effective radiation area and the shape factor with higher accuracy by increasing the number of orientations or by reducing the interval between orientations.

  Further, the computer may calculate the direct heat to the shape model using the parallel projection area, and may calculate the radiant heat using the parallel projection area and the effective radiation area. According to the present embodiment, parallel projection areas and effective radiation areas for various orientations can be stored, so high-precision radiation simulation can be performed in a short time while changing the form of the building and the position of the person in the building. It can be easily implemented.

  As described above, by using the projection area calculation program according to the present embodiment, it is possible to create a database of parallel projection areas and effective radiation areas. For example, after performing a radiation calculation of a room in advance, a person in the room It is possible to easily calculate the shape factor when the orientation and position of the are changed to various states. That is, it is possible to perform radiation simulation by calculating the form factor under various conditions based on the parallel projection area created in the database and the distance R and the direction θ between the room window and the person. Play.

<Second Embodiment>
[Calculate the boundary position of the part of the shape model]
FIG. 8 shows an example of a method for calculating the boundary position of the part of the shape model. The projected area calculation program further executes a step of calculating a boundary position of a plurality of parts based on at least one of an angle of a plurality of surface elements in contact with each other in the shape model and a density of the plurality of surface elements in the shape model. You may let them. In FIG. 8, an example of the result of calculating the boundary line between the rectangular parallelepiped first part and the cylindrical second part based on the angles of the plurality of surface elements constituting the projection image is displayed. . The computer may calculate and store at least one of a parallel projection area, an effective radiation area, and a form factor for each part determined based on the calculated boundary position.

  For example, the computer divides the shape model into a plurality of surface elements, and calculates a difference in direction between adjacent surface elements. The computer may determine that there is a boundary position between the adjacent surface elements when the difference in direction is greater than the threshold value. When the difference between the curvature of the first surface on which the first surface element is disposed and the curvature of the second surface on which the second surface element is disposed is greater than a threshold, the computer It may be determined that there is a boundary position between the part and the second surface. The computer can calculate the position of the boundary line of the part by connecting the positions determined to have the boundary position. The computer may display each of the plurality of parts surrounded by the boundary line with a different color or a different pattern.

  The computer may calculate the boundary positions of the plurality of parts based on the density of the plurality of surface elements constituting the projection image generated by the computer graphics software. For example, computer graphics software configures a first surface with a first surface element disposed at a first density, and is smaller than the first surface element at a second density greater than the first density. In the case of constituting the second surface on which the second surface element is arranged, the density of the first surface is smaller than the density of the second surface. Therefore, when the difference between the density of the first surface element group and the density of the second surface element group is larger than the threshold value, the computer determines that there is a difference between the first surface element group and the second surface element group. You may determine with it being the boundary position of a site | part.

  As described above, according to the projection area calculation program according to the present embodiment, the boundary lines of a plurality of parts in the projection image can be automatically calculated by the computer. Therefore, it is possible to calculate at least one of the parallel projection area, the effective radiation area, and the form factor for each part in a short time.

< Third Embodiment>
[Calculation method of parallel projected area when there is an obstacle]
FIG. 9 shows an example of a state where there is an obstacle in the vicinity of the shape model. FIG. 9 shows a state where a person is sitting on a chair. In order to enable calculation of the shape factor in such a state, the projection area calculation program obtains a shape model when viewed from at least one orientation in the step (S10) of acquiring a plurality of projection images in the computer. In the step (S120) of acquiring a plurality of projection images including an obstacle model overlapping at least a part of the region and calculating a plurality of parallel projection areas (S120), a region excluding a region overlapping the obstacle model among the plurality of projection images A plurality of parallel projection areas may be calculated based on the image.

  In the step (S110) of acquiring a plurality of projection images, the computer acquires a projection image including a shape model and an obstacle as shown in FIG. 9, for example. The computer may acquire projection images for a plurality of directions.

  In the step of calculating a plurality of parallel projection areas (S120), the computer calculates the area of the image of the region that does not overlap the obstacle when viewed from the direction in which the parallel projection area is calculated, thereby parallel to the direction. Calculate the projected area. The computer may automatically change the position of the obstacle with respect to the shape model and calculate the parallel projection area for each predetermined change amount.

  When the shape model is a human body, the radiant heat changes depending on the type of clothes, and therefore it is preferable to calculate the form factor according to the type of clothes. Therefore, the computer may further acquire a shape model of the clothes and calculate a parallel projection area corresponding to the shape of the clothes. The computer can easily calculate the form factor corresponding to the shape of the clothes by calculating and storing the parallel projection area and the effective radiation area for each shape of the clothes. By calculating the ratio of the effective radiation area corresponding to the type of clothes, the computer can calculate the amount of change in radiant heat due to clothes, which has been difficult to calculate conventionally, with high accuracy.

  As described above, according to the projection area calculation program according to the present embodiment, at least one of a parallel projection area, an effective radiation area, and a form factor is obtained using a projection image including a shape model and an obstacle model generated by a computer. By calculating, it is possible to easily calculate at least one of a parallel projection area, an effective radiation area, and a form factor viewed from a plurality of directions of the shape model while flexibly changing the position of the obstacle model with respect to the shape model. it can.

  As mentioned above, although this invention was demonstrated using embodiment, the technical scope of this invention is not limited to the range as described in the said embodiment. It will be apparent to those skilled in the art that various modifications or improvements can be added to the above-described embodiment. It is apparent from the scope of the claims that the embodiments added with such changes or improvements can be included in the technical scope of the present invention.

Claims (3)

On the computer,
Obtaining a plurality of projection images obtained by projecting a shape model having a plurality of parts from a plurality of directions;
Calculating a plurality of parallel projection areas of the plurality of portions based on the plurality of projection images corresponding to the plurality of orientations;
Storing the plurality of parallel projection areas of each of the plurality of portions in association with the plurality of directions ;
Calculating a solid angle based on at least one of the number of the plurality of orientations and the interval between the plurality of orientations;
Calculating an effective radiation area by accumulating the result of multiplying the solid angle by the parallel projection area corresponding to each of the plurality of orientations;
A projection area calculation program for executing the step of storing the effective radiation area in association with the parallel projection area . In the computer,
Claim 1 for further executing the step of calculating the boundary position of the plurality of parts based on at least one of the density of a plurality of face elements at an angle and the shape model of the plurality of face elements in contact with each other in the shape model projection area calculation program according to. On the computer,
In the step of acquiring the plurality of projection images, the plurality of projection images including an obstacle model that overlaps with at least a partial region of the shape model when viewed from at least one direction,
2. The step of calculating the plurality of parallel projection areas in the step of calculating the plurality of parallel projection areas based on an image of a region excluding the region overlapping the obstacle model among the plurality of projection images. Or the projection area calculation program of 2.

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