JP2011044358A - Lighting simulator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lighting simulator greatly reducing a computation load while considering light distribution when presenting a plurality of point light sources arranged in a light emitting region. <P>SOLUTION: An input part 1 inputs at least information for constructing a virtual space and information for specifying a light source. A modeling part 10 splits the light emitting region of the light source arranged in the virtual space into an outer periphery region ranging over the whole outer peripheral edge of the light emitting region and an inside region encircled by the outer periphery region. The point light sources are arranged in the outer periphery region. Besides, a bundle of rays emitted from the light emitting region of the light source is presented by a bundle of rays emitted from the point light sources arranged in the outer periphery region and a parallel bundle of rays emitted from the inside region. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an illumination simulator for simulating an illumination space using a three-dimensional virtual space by computer graphics.

  In recent years, various techniques for simulating an illumination space using a three-dimensional virtual space by computer graphics have been proposed. By visualizing the illumination state in the illumination space using this kind of technology, it is possible to examine the illumination state under various conditions before construction when designing the illumination environment.

  For example, in Patent Document 1, in an illumination simulator that visualizes an illumination state such as a light flow in an illumination space, the illumination space is divided into unit surfaces of small area units, and the illuminance of the unit surface is calculated based on the illumination conditions. In addition, a technique has been proposed in which lattice points of a three-dimensional lattice are set in the illumination space and the illumination state at each lattice point is calculated based on the illuminance value of the unit surface.

  In the technique described in Patent Document 1, the illuminance on the unit surface is calculated based on illumination conditions such as the position of the light source, the luminous flux, and the light distribution. The illumination state of each grid point is represented by the illuminance at the grid point and the flow of light through the grid point. The illuminance at the grid point forms a virtual sphere centered on the grid point, and The illuminance on the surface is obtained by summing up, and the flow of light passing through the lattice points is obtained by dividing the solid points around the lattice points into equal solid angles and calculating the magnitudes of vectors in each direction.

JP 7-36360 A

  In the technique described in Patent Document 1, an example in which a light source is arranged in an illumination space is shown, but the illuminance for each unit surface is only calculated based on illumination conditions such as the position of the light source, the luminous flux, and the light distribution. There is no particular description on how to set the lighting conditions. Although there is no specific description regarding the light source in Patent Document 1, it is considered that a lighting fixture using a straight tube fluorescent lamp is assumed from the figure, but how the light flux and light distribution are handled? It is unknown.

  Most of the light sources generally used are incandescent bulbs or fluorescent lamps, and various shapes such as a bulb type, a straight tube type, and an annular shape are adopted. On the other hand, recently, it has been proposed to use a light source having a light emission principle different from that of an incandescent bulb or a fluorescent lamp for illumination, such as a light emitting diode or an organic EL. When this type of light source is used, it is possible to easily realize a lighting fixture having a free shape in which the light emitting region is linear or planar. In the present situation where the types of light sources are abundant in this way, it can be said that setting the illumination conditions appropriately for the light sources is an indispensable matter for simulation of the illumination space.

  By the way, when a light source is arranged in computer graphics, it is considered to use a point light source or a surface light source and calculate the illuminance in a three-dimensional space using a technique such as radiosity. The point light source and the surface light source are idealized, and the point light source is expressed as emitting light flux uniformly in all directions.

  For example, a surface light source is expressed by arranging point light sources S1 at regular intervals in the light emitting region D0 as shown in FIG. Therefore, the light emitting region D0 can be treated equivalently to a complete diffusion surface that uniformly emits a light beam in the front direction.

  If it is going to give the light distribution characteristic to such a light emission area | region D0, it is possible to give a light distribution characteristic to each point light source S1 which comprises the light emission area | region D0, but all the light emission area | regions D0 contain. If the light distribution characteristic is individually given to the point light source S1, the calculation load becomes very large.

  In particular, if the conditions of the position and shape of the light emitting region D0 are changed, recalculation must be performed for all the point light sources S1 forming the light emitting region D0 even if only a few conditions are changed. Therefore, there is a problem that the calculation load becomes very large and a long time calculation is required. This problem occurs not only in the surface light source but also in the line light source.

  The present invention has been made in view of the above reasons, and its purpose is to consider light distribution when a light source having a spread, such as a line light source or a surface light source, is expressed by a set of a plurality of point light sources. However, an object of the present invention is to provide an illumination simulator capable of significantly reducing the calculation load as compared with the prior art.

  In order to achieve the above object, the present invention is a lighting simulator for evaluating a lighting environment by generating a virtual space equivalent to a real space for a three-dimensional lighting space by a computer and performing a lighting calculation in the virtual space. The input unit for inputting at least information for constructing the virtual space and information for defining the light source, and the light emitting region of the light source arranged in the virtual space are arranged in the outer peripheral region and the outer peripheral region over the entire outer periphery of the light emitting region. The light source is divided into the enclosed inner area, the point light source is arranged in the outer peripheral area, and the light beam emitted from the light emitting area of the light source is emitted from the point light source arranged in the outer peripheral area and the inner area. And a modeling unit represented by a parallel light flux.

  It is desirable that the modeling unit employs, in the illumination calculation, a light bundle emitted from the point light source to the outside of the light emitting region.

  In addition, the modeling unit preferably includes a shape changing unit that deforms the light emitting region by operating the input unit.

  In this case, the modeling unit includes a storage unit that stores in advance a reference shape that is a basic shape of the light emitting region and includes a plurality of lattice points, and the shape changing unit is a bounding box that is a circumscribed rectangle of the reference shape. It is desirable that an operation of deforming the reference shape by deforming the reference shape and an operation of deforming the reference shape by moving the lattice points provided in the reference shape are possible.

  Furthermore, the modeling unit preferably includes an optimization unit that determines the position of the point light source in accordance with the shape of the outer peripheral region so that the arrangement intervals of the point light sources are equalized.

  In addition, the modeling unit has a light distribution characteristic determined by the arrangement / posture setting unit for determining the light distribution characteristic by operating the input unit for one of the point light sources in the outer peripheral region and the light distribution characteristic determined by the arrangement / posture setting unit for the remaining point light sources. It is desirable to provide a point light source allocating unit that applies

  In addition, the modeling unit automatically distributes the light flux between the outer peripheral area and the inner area so that there is no boundary between the light beam of the point light source arranged in the outer peripheral area and the light flux of the parallel light flux emitted from the inner area. It is desirable to provide a luminous flux allocating unit that

  According to the configuration of the present invention, the light emitting region of the light source is divided into an outer peripheral region and an inner region, and the outer peripheral region is modeled by arranging a point light source, and the light flux emitted from the light emitting region is emitted from the point light source. Therefore, in the calculation of illumination, the light emitting area is emitted from the inner area and the characteristics of a small number of point light sources arranged in the outer peripheral area. It is only necessary to consider the characteristics of the uniform parallel light flux, and the calculation load is greatly reduced as compared with the conventional configuration in which the characteristics of a large number of point light sources are considered. In addition, as a result of reducing the calculation load, it is possible to perform the lighting calculation when the lighting conditions are changed in a short time, and it is also possible to perform the lighting calculation in real time, depending on the computer's calculation capability. is there.

  If the light flux emitted from the point light source is emitted to the outside of the light emitting area, it is compared with the case where all the light flux emitted from the point light source is used for the illumination calculation. Thus, the calculation load can be further reduced.

  In addition, by making it possible to deform the light emitting area by operating the input unit, it becomes possible to arrange light emitting areas of various shapes in the virtual space.

  In particular, if a light emitting region is formed by deforming a reference shape having a plurality of lattice points by deforming the bounding box or moving the lattice points, the light emitting region can be formed into a free shape with a simple operation. It becomes possible.

  In the configuration in which the arrangement intervals of the point light sources are automatically equalized, the peripheral area can be regarded as one continuous light source even though the outer peripheral area is substituted with the point light source. Increases accuracy. That is, it is possible to perform accurate illumination calculation while reducing the calculation load.

  Further, in the configuration in which the light distribution characteristic determined for one point light source in the outer peripheral area is applied to the remaining point light sources, the light distribution characteristic of the outer peripheral area is determined only by adjusting the light distribution characteristic of only one point light source. This makes it easy to generate a model of the light emitting area.

  In the configuration in which the light flux is distributed so that there is no boundary between the light flux between the outer peripheral area and the inner area, there is no unnatural feeling due to the light flux being reduced or increased only at the periphery of the light emitting area. .

It is a block diagram which shows embodiment. It is operation | movement explanatory drawing same as the above. It is a figure which shows the example of the basic shape used for the same as the above. It is explanatory drawing of the coordinate system used for the same as the above. It is a figure explaining the deformation | transformation method of the basic shape same as the above. It is a figure which shows the modification of the basic shape in the same as the above. It is a figure which shows the modification of the basic shape in the same as the above. It is a figure explaining operation | movement of the optimization part in the same as the above. It is a figure explaining the example of arrangement | positioning of the point light source in the same as the above. It is a figure explaining the example of arrangement | positioning of the point light source in the same as the above. It is a figure explaining the example of a setting of the light distribution characteristic in the same as the above. It is a figure explaining the definition of the angle in the same as the above. It is a figure explaining the effective range of the horizontal angle in the same as the above. It is a figure explaining the effective range of the vertical angle in the same as the above. It is a figure explaining the effective range of the vertical angle in the same as the above. It is a figure explaining the effective range of the vertical angle in the same as the above. It is a figure explaining the relationship of the light beam of the outer periphery area | region and inner area | region in the same as the above. It is a figure which shows the example which applied the same as the line light source. It is a figure which shows the example which applied the same as the light emission area | region which radiates | emits a light beam on both surfaces. It is a figure which shows the model in a conventional structure.

  An object of the present invention is to facilitate the setting of the shape, light distribution, position, and luminous flux of a light source in a virtual space equivalent to a real space when a lighting space is simulated using a computer. In the embodiments described below, the term “light source” is used to mean a surface having a function of emitting a light bundle. Therefore, the definition of “light source” in the present invention does not include an idealized point light source or line light source.

  Even if the point light source and the line light source are excluded from the “light source” in this way, the light source in the real space generally has an area in the light emitting region. However, in the present invention, it is not excluded to arrange a point light source or a line light source in the virtual space, but if a single point light source is arranged alone in the virtual space, the point light source can be represented. If a plurality of point light sources are arranged side by side on a line (may be on a straight line or a curved line), a line light source can be represented. Further, the “light source” may be not only the light emitting surface of the lamp but also the light emitting surface of a lighting fixture, and a surface that emits a light bundle by reflecting light, such as an object surface, may be treated as a “light source”. Is possible.

  In the present invention, in order to achieve the above object, as shown in FIG. 8, the light emitting region D0 (FIG. 8A) of the light source is changed to the entire outer periphery of the light emitting region D0 as shown in FIG. The outer peripheral region D1 is divided into two, and the inner region D2 surrounded by the outer peripheral region D1 as shown in FIG. 8C, and a uniform parallel light beam is radiated from the inner region D2, and the outer peripheral region D1 This is treated as a configuration having a configuration in which a light beam is emitted from a plurality of point light sources S arranged along the outer peripheral edge of the light emitting region D0. In short, the light emission region D0 is modeled into a configuration having an outer peripheral region D1 and an inner region D2, and illumination calculation is performed.

  The light distribution in the light emitting area can be determined by providing a light distribution characteristic in the radiation direction of the light beams E1 and E2 in the outer peripheral area D1 and the inner area D2. The luminous flux E1 in the outer peripheral area D1 is determined as a combination of the light bundles emitted from the point light source S provided in the outer peripheral area D1, and the luminous flux E2 in the inner area D2 is the luminous intensity of the parallel luminous flux and the area of the inner area D2. And determined by. Accordingly, the total luminous flux E0 in the light emitting area D0 is represented by the sum of the luminous flux E1 emitted from the outer peripheral area D1 and the luminous flux E2 emitted from the inner area D2.

  The present invention relates to a technique of defining a lighting condition at a stage between a stage of setting a virtual space corresponding to an actual space and a stage of calculating a simulation of the lighting space in the virtual space. Yes, the following functions are realized by executing the program on a computer.

  The functions realized by the computer by executing the program are shown in FIG. FIG. 1 shows elements for setting the illumination conditions of the light source. The function of constructing the virtual space is realized in the input unit 1 as necessary. The function for calculating the illuminance on the surface of the object in the virtual space and the function for calculating the flow of the light beam in the virtual space are realized in the calculation unit 9 as necessary. These functions can be realized by using well-known techniques described in prior art documents. A feature of the present invention is that the light emitting area D0 of the light source arranged in the virtual space is modeled so that the illumination calculation in the calculating unit 9 is easy. The modeling unit 10 is used for modeling the light emitting area D0. Provided.

  The input unit 1 has a function of inputting necessary items related to a light source such as illumination conditions in the virtual space (light source shape, light distribution, position, light flux). Specifically, the lighting conditions are interactively input by inputting necessary items into the input fields and check boxes displayed on the screen of the monitor device 11 in the computer using a keyboard and a mouse. However, if there is separate data such as design data regarding the light source conditions in the virtual space, the illumination conditions may be input by reading those data.

  First, the outline of the illumination condition setting procedure in the modeling unit 10 of the present embodiment will be briefly described with reference to FIG. The input unit 1 selects a geometrically defined reference shape (S1), and then the shape changing unit 2 changes the reference shape to a desired shape by operating the input unit 1, and emits light of the desired shape. It forms in area | region D0 (S2). Of course, no modification is required when the desired shape of the light emitting region D0 matches the reference shape. The specific operation of the shape changing unit 2 will be described later.

  When the shape of the light emitting region D0 is determined by the shape changing unit 2, the light emitting region D0 of the light source is divided into two, the outer peripheral region D1 and the inner region D2, as described above. The process of dividing the outer region D1 and the inner region D2 is performed by the optimization unit 3, and the optimization unit 3 further arranges a plurality of point light sources S in the outer region D1 (S3). That is, the optimization unit 3 determines the number and interval of the point light sources S arranged in the outer peripheral region D1.

  Next, in the posture setting unit 4, the spread of the light beam is determined for one of the point light sources S arranged in the outer peripheral region D1 according to the illumination condition instructed by the input unit 1 (S4). The direction in which the light beam is emitted is determined (S5). When the orientation setting unit 4 determines the direction and spread of the light beam emitted from one point light source S in this way, the point light source assignment unit 5 determines all the point light sources arranged in the outer peripheral region D1. The direction and spread of the light beam are determined (S6).

  When the characteristics of the direction and spread of the light beam are determined for each point light source S arranged in the outer peripheral region D1, the orientation setting unit 4 determines the direction of the parallel light beam in the inner region D2. The direction of the light flux from the point light source S (the direction of the maximum luminous intensity) is matched (S7). In this way, the direction and spread of the light flux between the outer peripheral area D1 and the inner area D2 are determined. Furthermore, the direction setting unit 6 extracts only data relating to the luminous flux emitted in the direction necessary for the illumination calculation as valid data (S8).

  Thereafter, in the light beam allocating unit 7, all the point light sources S in the outer peripheral region D 1 and the parallel light fluxes in the inner region D 2 are respectively determined based on the illumination condition (total light beam in the light emitting region D 0) input from the input unit 1. Necessary luminous fluxes are distributed (S9), and luminous fluxes radiated from the respective point light sources S and luminous fluxes per unit area of the parallel light flux are determined (S10).

  The illumination simulator of the present embodiment includes a storage unit 8. The storage unit 8 includes a reference shape related to the light emission region D0 of the light source, a light distribution characteristic of the point light source S arranged in the outer peripheral region D1, a virtual space used for illumination calculation, and illumination. Various data such as the results of calculation are stored. The data stored in the storage unit 8 includes various data generated in the process described above, in addition to data registered in advance. Data stored in the storage unit 8 is read and used as necessary. Data temporarily stored in the above process is deleted when it becomes unnecessary.

  In the following, the function of each element shown in FIG. 1 will be described in detail. As described above, the illumination condition is input from the input unit 1, and a geometrically defined reference shape for determining the shape of the light emitting region D0 of the light source is selected by operating the input unit 1. The reference shape T is a simple geometric shape, and is selected from any one of a square shape as shown in FIG. 3A and a circular shape as shown in FIG. . The inside of the reference shape T is regularly divided into a plurality of portions.

  When the reference shape T is a square as shown in FIG. 3A, the reference shape T is divided into a mesh by a plurality of straight lines along each side. When the reference shape is circular as shown in FIG. 3B, the reference shape is divided into a mesh shape by a plurality of straight lines passing through the center of the reference shape T and a plurality of concentric circles. In this manner, the reference shape T is provided with a plurality of lattice points G by dividing the inside of the reference shape T into a mesh shape. When the reference shape T is a square, the intersection of straight lines orthogonal to each other, the vertex of the reference shape T, and the intersection of each side of the reference shape T and the straight line are lattice points G, respectively. Further, when the reference shape T is circular, the intersections of the reference shape T and concentric circles with the respective straight lines are lattice points G, respectively. When the reference shape T is divided, the dimension at the time of division is defined so that the interval between the adjacent lattice points G is relatively small in the real space (for example, about 5 [cm] at the maximum).

  As for the size of each reference shape T, the user instructs a desired value through the input unit 1 or the shape changing unit 2 monitors the reference shape T having a specified dimension (for example, 10 cm square) as an initial value. After presenting to the device 11, the user is allowed to adjust the dimensions. The shape changing unit 2 has a function of allowing the user to change the aspect ratio of the reference shape T through the input unit 1. If the reference shape T is a square, the shape changing unit 2 can be transformed into a rectangle. If the shape T is circular, it can be deformed into an ellipse.

  In the following, for ease of explanation, a coordinate system is set and explained. As shown in FIG. 4, the coordinate system is set so that the plane parallel to the reference shape T is the xz plane and the light bundle E is emitted in the negative direction in the y-axis direction for the light emitting region D0 of the reference shape T. It shall be. The position of the origin of this coordinate system is set to an appropriate position in the virtual space.

  In the shape changing unit 2, the reference shape T is deformed by deforming the outer shape of the reference shape T or moving the position of each lattice point G included in the reference shape T.

  As shown in FIG. 5, a bounding box BB that is a circumscribed rectangle is defined in the reference shape T. When the reference shape T is selected on the screen of the monitor device 11, the mouse is moved to the reference shape T and clicked. Then, a bounding box BB surrounding the reference shape T is displayed on the screen of the monitor device 11 as shown in FIG. An anchor point AP is displayed at each vertex position of the bounding box BB and at the center of each side of the bounding box BB. When these anchor points AP are operated with a mouse (pointing device) (dragging), the bounding box BB can be deformed, and as a result, the reference shape T can be deformed.

  The operation of the anchor point AP is the same as the operation generally used for drawing in computer graphics. That is, in the state where eight anchor points AP are displayed, if the anchor point AP at the vertex position of the bounding box BB is dragged as shown in FIG. 5A, the vertical and horizontal dimensions of the bounding box BB are simultaneously changed. can do. Also, by dragging the anchor point AP located at the center of the upper or lower side of the bounding box BB, the vertical dimension of the bounding box BB can be changed, and the anchor point AP located at the center of the left or right side of the bounding box BB is changed. By dragging, the horizontal dimension of the bounding box BB can be changed.

  Further, when the mode is switched by clicking the mouse or the like, only the four anchor points AP at the vertex positions of the bounding box BB are displayed, and the anchor point is dragged by the anchor point AP as shown in FIG. The position of the AP can be freely moved. That is, in the mode of FIG. 5 (a), the bounding box BB is kept rectangular, but in the mode of FIG. 5 (b), the bounding box BB can be deformed into a rectangular shape.

  To move the grid point G, select the desired grid point G (click with the mouse) and specify the coordinate position from the input unit 1 or move the mouse cursor to the desired grid point G and drag. . In the latter case, the position of the grid point G can be operated intuitively, but the coordinate position of the grid point G is displayed in an appropriate area (for example, a status bar or a palette) on the screen of the monitor device 11. Here, since there are a large number of grid points G, only the coordinate positions of the selected grid points G are displayed.

  For example, by moving the lattice point G with respect to the reference shape T in FIG. 6A, it is possible to form the light emitting region D0 having a shape as shown in FIG. 6B. In addition, you may add the function which displays not only the coordinate position of the grid point G but the dimension and shape after deformation | transformation of bounding box BB on the screen of the monitor apparatus 11. FIG. Further, as in the case of a circular shape described later, the reference shape T can be deformed in the y-axis direction by moving the lattice point G in the y-axis direction.

  The above example shows a case where the reference shape T is a square. However, when the reference shape T is a circle, the grid point G is not moved in a plane parallel to the xz plane, and the reference shape T The deformation of is performed only by deformation of the bounding box BB. On the other hand, since the bounding box BB is set in a plane parallel to the xz plane, the reference shape T cannot be deformed by the bounding box BB in the y-axis direction. Therefore, in the y-axis direction, the reference shape T is deformed by moving the lattice point G.

  Therefore, as shown in FIGS. 7A and 7B, the monitor device 11 shows the in-plane shape parallel to the xz plane and the in-plane shape parallel to the xy plane. The reference shape T is deformed only by the bounding box BB within a plane parallel to the XY plane, and the reference shape T is deformed only by movement of the lattice point G within a plane parallel to the zy plane.

  The bounding box BB is set to be a circumscribed rectangle even when the reference shape T is circular, as in the case where the reference shape T is square. That is, when the reference shape T is circular, as shown in FIG. 7A, the reference shape T is surrounded by a closed curve having no discontinuous points even after deformation in a plane parallel to the xz plane.

  Note that when the reference shape T is circular, the lattice point G is not moved in a plane parallel to the xz plane for the following reason. That is, when the grid point G is moved when the reference shape T is circular, the partial arcs are discontinuously connected with the grid point G, and the distance between a pair of adjacent grid points G is in real space. Since the dimensions are set to be relatively small (for example, about 5 [cm]), it can be said that even if the curve between the lattice points G is approximated by a straight line, no large error occurs in the shape of the light source. In this way, the shape approximating the curve connecting the lattice points G with a straight line is a shape that can be realized even by deforming the reference shape T as a square, so that the lattice point G is moved from the circular reference shape T. There is no point in transforming. Therefore, when the reference shape T is circular, the lattice point G is not moved in a plane parallel to the xz plane.

1. Point Light Source Arrangement The shape of the light source generated from the reference shape T by the shape changing unit 2 is given to the optimization unit 3. As shown in FIG. 8, the optimization unit 3 first divides the light emitting region D0 of the light source into two parts, an outer peripheral region D1 and an inner region D2. The outer peripheral area D1 means the outer peripheral edge of the light emitting area D0, and the inner area D2 means an area other than the outer peripheral edge of the light emitting area D0. Therefore, the inner area D2 substantially occupies the entire surface of the light emitting area D0 of the light source. In the optimization unit 3, a point light source S (see FIG. 8) is arranged in the outer peripheral region D1, and the inner region D2 is treated as a light emitting surface that emits a parallel light flux.

  The optimization unit 3 divides the light emitting region D0 into the outer peripheral region D1 and the inner region D2, and then arranges the point light source S in the outer peripheral region D1. That is, the number and interval of the point light sources S arranged in the outer peripheral area D1 are determined, and the coordinate position of each point light source S is determined. The optimization unit 3 determines the coordinate position of the point light source S in the outer peripheral region D1 according to the following procedure. The procedure for determining the coordinate position of the point light source S differs depending on whether the reference shape T is a square or a circle.

a. When the reference shape T is a square When the reference shape T is deformed from the reference shape T, the light source becomes a quadrangle when only the bounding box BB is deformed, and when the lattice point G is moved, the light source is a polygon (convex polygon). And a concave polygon). In either case, the position of the point light source S can be determined by the following procedure.

  (1) The point light source S is arranged at the position of the vertex of the light source, and the length dimension Bn (n = 1, 2,...) Is obtained for each side.

(2) Using the length dimension Bmin of the shortest side, the division number M of the shortest side by the point light source S is determined by the following relationship. The division number M is M = m + 1, where m is the number of point light sources S arranged on the shortest side excluding the vertex of the light source.
a × (M−1) <Bmin <a × M
That is, M = [Bmin / a] +1. Here, [x] means the quotient of x, and the constant a is a specified value given as the maximum value of the distance between the point light sources S, and is, for example, a value corresponding to 5 [cm] in real space. Set.

(3) In order to determine the reference value K ′ of the interval between the point light sources S in increments of a predetermined dimension b (for example, 5 mm), the value of the reference value K ′ that minimizes the following equation is expressed as {a−ib, a− (I-1) Obtained from the range of b,..., Ab, a}. i is an appropriate positive integer. If a = 5 [cm], b = 5 [mm], and i = 8, the reference value K ′ is {1, 1.5,..., 4.5, 5} with [cm] as a unit. It is calculated from the range.
| Bmin / M-K '|
(4) A reference value Kn ′ of the distance between the point light sources S for each side is obtained from the length dimension Bn of each side by the following equation.
Kn ′ = Bn / [Bn / K ′]
Here, [Bn / K ′] corresponds to the number of divisions of the side when the point light sources S are arranged on the side at intervals of the reference value K ′. Therefore, it can be said that the reference value Kn ′ of the interval is a temporary interval of the point light source S on the side.

(5) Based on the difference between the reference value K ′ and the reference value Kn ′, the interval Kn for arranging the point light sources S on each side is determined as follows.
If Kn′−K ′> b, then Kn = Bn / ([Bn / K ′] + 1) (Rule 1)
If −b ≦ Kn−K ′ ≦ b, then Kn = Kn ′ (Rule 2)
If Kn−K ′ <− b, then Kn = Bn / ([Bn / K ′] − 1) (Rule 3)
In this way, the interval Kn of the point light sources S for each side is determined so that the variation in the interval of the point light sources S on each side is within a range of ± b.

  In the above-described procedure (2), the constant a that defines the maximum value of the interval between the point light sources S can be used as a substitute for a single continuous light source for the plurality of point light sources S arranged in the outer peripheral region D1. It is set to a size of about. Accordingly, if the constant a is set to a small value, the accuracy of the light source simulation can be improved. However, in practice, if a = 5 [cm] is set as in the above example, the condition can be satisfied. .

  A specific example in which the interval Kn of the point light sources S is determined by the procedures (1) to (5) will be shown below. In this example, it is assumed that the light emitting region D0 formed by the shape changing unit 2 has the shape of FIG. FIG. 9A shows a state in which the point light sources S are arranged at the positions of the vertices of the outer peripheral area A1. The length of each side is B1 = 14.5 [cm], B2 = 17.0 [cm], B3 = 7.8 [cm], B4 = 9.2 [cm], and the constants described above It is assumed that a is 5 [cm] and the predetermined dimension b is 5 [mm].

  In this example, since the length dimension Bmin of the shortest side is Bmin = B3 = 7.8 [cm], the division number M of the shortest side is M = [7.8 / 5] + 1 = 1 + 1 = 2. Become. That is, since Bmin / M = 7.8 / 2 = 3.9, the reference value K ′ of the interval between the point light sources S is in the range of {1, 1.5,..., 4.5, 5}. If Bmin / M−K ′ | = | 3.9−K ′ | is selected as a value that minimizes, K ′ = 4 [cm].

Accordingly, the reference values K1 ′, K2 ′, K4 ′ of the intervals between the point light sources S on the other side are obtained as follows.
K1 ′ = 14.5 / [14.5 / 4] = 14.5 / 3≈4.833
K2 '= 17 / [17/4] = 17/4 = 4.25
K4 '= 9.2 / [9.2 / 4] = 4.6
Therefore, K1′−K′≈0.833, and the condition of (Rule 1) described above is satisfied. Therefore, K1 = 14.5 / ([14.5 / 4] +1) = 14.5 / 4 = 3 .625. Since K2′−K ′ = 0.25, which satisfies the above-mentioned (Rule 2), K2 = 4.25. Furthermore, since K4′−K ′ = 0.6 and the condition of (Rule 1) is satisfied, K4 = 9.2 / ([9.2 / 4] +1) = 3.067.

  According to the above procedure, the number of point light sources S arranged on each side becomes 3, 3, 1, and 2 as shown in FIG. 9B. Therefore, the number of point light sources S arranged in the outer peripheral area A1 is 13 in total including the point light sources S arranged at the respective vertices.

  In the above example, K2 = 4.25 [cm], K4 = 3.067 [cm], and between the maximum value and the minimum value of the distance between the point light sources S arranged on different sides. Since there is a difference of 1 [cm] or more, the difference between the maximum value and the minimum value may be adjusted to be small by recalculating the interval K2 or the interval K4. For example, when adjusting the interval K2, as shown in FIG. 9C, the number of point light sources S is increased by one, and K2 = 17 / ([17/4] +1) = 17/5 = 3. What is necessary is just 4 [cm]. As described above, if the distance K2 is adjusted, the difference between the maximum value and the minimum value of the distance of the point light source S becomes K3−K4 = 3.9−3.067 = 0.833 [cm]. The variation in the S interval can be reduced.

  As described above, when the variation in the interval between the point light sources S arranged on each side exceeds a specified value (for example, 1 [cm]), the operation of increasing the number of point light sources S on an appropriate side can be repeated. For example, it is possible to reduce the variation in the distance between the point light sources S. However, if the point light source S is added to reduce the distance between the point light sources S to a minimum value or less, the difference between the maximum value and the minimum value of the distance increases.

  For example, in the above-described example, when one point light source S is added to the shortest side (the right side in the figure), K3 = 7.8 / 3 = 2.6 [cm]. Here, as described above, after adjusting to K2 = 3.4 [cm] (see FIG. 9C), the maximum value of the distance between the point light sources S is K1 = 3.625 [cm]. Therefore, the difference between the maximum value and the minimum value of the interval is 3.625−2.6 = 1.005 [cm], and eventually the difference between the maximum value and the minimum value of the interval is increased. .

  Therefore, when adding the point light source S, the number of point light sources S in the shortest side is not increased, the point light source S is added to the side where the distance between the point light sources S is maximum, and the distance between the point light sources S is minimum. It is determined whether or not the value is less than or equal to the value.

  By the way, the parameters defining the point light source S are as shown in Table 1, the identifier for distinguishing the point light source S, the three-dimensional coordinate position of the point light source S, and the direction of the optical axis of the point light source S (described later). (Direction of maximum luminous intensity), a horizontal effective range and vertical effective range described later, and a luminous intensity within the range described later. These parameters are stored in the storage unit 8. Since the optimization unit 3 determines the coordinate position, only the identifier and the coordinate position among the parameters in Table 1 are stored in the storage unit 8 after the processing in the optimization unit 3.

基準形状Ｔが正方形である場合に、点光源Ｓの間隔を決定するにあたって、上述の手順のほか、以下の手順を採用することも可能である。すなわち、上述の手順では、最短辺の長さ寸法Ｂｍｉｎに基づいて各辺における点光源Ｓの間隔を順に決定しているが、すべての辺について点光源Ｓの間隔を同時に決定する手順を採用することも可能である。

In the case where the reference shape T is a square, in determining the interval between the point light sources S, the following procedure can be adopted in addition to the above-described procedure. That is, in the above-described procedure, the interval between the point light sources S on each side is sequentially determined based on the length dimension Bmin of the shortest side, but a procedure for simultaneously determining the intervals between the point light sources S for all sides is adopted. It is also possible.

  (1) is similar to the procedure described above.

  (2) A temporary interval Jn is set for the point light source S, and the division number Mn ′ and the remainder Rn, which are quotients of Bn / Jn, are obtained for the side length dimension Bn (Jn × Mn ′ + Rn = Bn). ). Here, if Rn / Mn ′ <c with respect to the specified value c, Jn + Rn is set as a candidate for the interval between the point light sources S. The specified value c is set to 5 mm, for example. Further, the temporary interval Jn is decreased in increments of a predetermined dimension e starting from the maximum interval d. For example, if the maximum distance d is 5 [cm] and the predetermined dimension e is 5 [mm], the distance Jn is 5.0 [cm], 4.5 [cm], 4.0 [cm],. Will change. Here, the provisional interval Jn applies the same value to all sides, and judges whether or not “Rn / Mn ′ <c” for each side.

  (3) When the candidate of the interval of the point light source S is obtained for all the sides of the light source at the time when the temporary interval Jn becomes a certain value, the detection of the candidate of the interval is finished. As described above, the temporary interval Jn is gradually decreased to obtain the interval candidate, and therefore the temporary interval Jn is the minimum value Jmin at this point. Here, although the number of candidates for the interval between the point light sources S does not always coincide with each side, at least one candidate is obtained for each side.

  (4) The minimum value of the distance candidates (Jn + Rn) of the point light sources S obtained for each side is obtained and used as a reference value for the distance, and for the other sides excluding the side for which the reference value is obtained, the relevant side is obtained. Among the candidates, the candidate having the smallest difference from the reference value is selected.

  (5) If the difference between the candidate points of the point light source S on each side selected in this way (the difference between the maximum value and the minimum value) is less than the specified value c, the candidate of the point light source S on each side (Jn + Rn) is adopted as the interval between the point light sources S on the side.

  In step (5), when the difference between the candidate intervals of the point light sources S on each side is equal to or greater than the specified value c, a value obtained by subtracting the specified value c from the minimum value Jmin of the temporary interval Jn is set to the temporary interval Jn. (I.e., using Jn = Jmin-c) to obtain a candidate for the interval (Jn + Rn). However, a minimum value d is defined for the provisional interval Jn, and if the difference between the candidate intervals of the point light source S on each side does not become less than the specified value c even if the minimum value d is used, each side is determined. Even if the obtained difference between the interval candidates of the point light sources S is equal to or larger than the specified value c, the interval candidate that minimizes the difference between the interval candidates is adopted as the interval between the point light sources S on each side.

b. When the reference shape T is circular As described above, when the reference shape T is circular, only the deformation using the bounding box BB is possible in a plane parallel to the xz plane. Becomes a closed curve. With respect to this curve, a circumscribed circle Cc is set as shown in FIG. 10, a straight line passing through the center of the circumscribed circle Cc is set at a constant angular interval ω, and the intersection of each straight line and the outer peripheral region D1 is arranged at the point light source S. Position. When the radius of the circumscribed circle Cc is r and the desired interval between the point light sources S is e, the angular interval ω is set so that rω ≦ e. The interval e is set to 5 [cm], for example.

  Although the outer peripheral area D1 is not circular in FIG. 10, the same applies to the case where the outer peripheral area D1 is circular, and the outer peripheral area D1 coincides with the circumscribed circle Cc. If the outer peripheral area D1 of the light source is elliptical, the arc length can be accurately obtained by using the elliptical formula, but the calculation load is reduced and high-speed computation is possible. Therefore, variation in the interval between the point light sources S is allowed. However, if the distance e between the point light sources S is set appropriately, a plurality of point light sources S can be substituted for one continuous light source, and therefore there is some variation in the distance between the point light sources S. Is also practically acceptable.

  Further, in the virtual space, the curve is approximated by a short straight line group, and each sector shape obtained by dividing the circumscribed circle Cc is approximated by a triangle.

  Note that the shape of the light emitting region D0 of the light source can be changed in a timely manner. When the shape of the light emitting region D0 is changed or the area of the light emitting region D0 is changed, the optimization unit 3 makes a point. It is necessary to reset the arrangement of the light sources S.

2. Setting of light distribution characteristics In the optimization unit 3, the light emitting region D0 of the light source is divided into the outer peripheral region D1 and the inner region D2, and the arrangement position of the point light source S in the outer peripheral region D1 is determined. The light source allocation unit 5 and the direction setting unit 6 determine the light distribution of the light emitting region D0. In order to determine the light distribution of the light emitting region D0, first, the posture setting unit 4 determines the light distribution characteristics (direction and spread of the light bundle) for one point light source S arranged in the outer peripheral region D1, and then the point setting unit 4 The light source allocation unit 5 determines the light distribution characteristics of all the point light sources S, and the direction setting unit 6 determines the direction of the parallel light bundles in the inner region D2.

  First, the operation of the posture setting unit 4 will be specifically described.

  (1) One appropriate point light source S is selected from the point light sources S whose positions have been determined by the optimization unit 3 as shown in FIG. The user can select the point light source S by operating the input unit 1. However, as shown in Table 1, the point light source S stored in the storage unit 8 can be adopted or set in the virtual space. The point light source S may be automatically selected by adopting the point light source S that is the shortest distance from the appropriate viewpoint position.

  (2) When one point light source S is selected, the user designates the light distribution characteristic of the point light source S using the input unit 1. Here, the point light source S does not radiate the light flux isotropically over the entire circumference, but has directivity for the radiation of the light flux. Therefore, the light distribution characteristic of the point light source S is represented by the optical axis (virtual axis indicating the direction of the maximum luminous intensity) and the luminous intensity distribution with respect to the optical axis.

  In order to determine the light distribution characteristics of the selected point light source S, the posture setting unit 4 determines the three-dimensional position of the point light source S in the virtual space and the direction of the optical axis of the point light source S in the virtual space. decide. As shown in FIG. 12, the position of the point light source S is represented by a three-dimensional coordinate position (x, y, z) in the coordinate system defined in the virtual space, and the direction of the optical axis Ax is the position of the light source S. It is represented by an angle (α, β, γ) formed by the optical axis Ax with respect to each of three straight lines parallel to each coordinate axis of the coordinate system defined in the virtual space as the origin. Since the position of the point light source S is determined by the optimization unit 3, the orientation setting unit 4 determines the direction of the optical axis of the point light source S.

  When determining the direction of the optical axis, the light distribution curve of the point light source S is shown on the screen of the monitor device 11 as shown in FIG. In this state, the direction of the optical axis Ax is adjusted by inputting a numerical value from the input unit 1 or by dragging the optical axis Ax using the input unit 1. The determined direction of the optical axis Ax is stored in the storage unit 8 in association with the identifier of the point light source S as shown in Table 1.

  As for the light distribution characteristics of the point light source S, default values in a state where the optical axis Ax is defined in the negative direction in the y-axis direction are registered in the storage unit 8 in the format shown in Table 2, and these light distribution characteristics Select what you need. The light distribution characteristics can be additionally registered in the storage unit 8 as necessary. Further, the light distribution characteristic can be changed by inputting a numerical value from the input unit 1 or by dragging the light distribution curve using the input unit 1. In order to deform the light distribution curve by dragging, it is desirable to use a bounding box as in the case where the reference shape T is deformed for the light source.

表２では、点光源Ｓの配光特性を、鉛直角度と水平角度との光度との組み合わせにより表している。すなわち、図１２のように、点光源Ｓの位置を原点として仮想空間における光線Ｌの方向を、当該方向がｙ軸となす角度φ（鉛直角度）と、当該方向をｘｚ平面に投影した写像（直線）がｘ軸となす角度θ（水平角度）との組で表し、角度φと角度θとの組で表される光線Ｌの方向ごとに光度ｑを対応付けることにより点光源Ｓの配光特性を表している。

In Table 2, the light distribution characteristic of the point light source S is represented by a combination of the luminous intensity of the vertical angle and the horizontal angle. That is, as shown in FIG. 12, the direction of the light beam L in the virtual space with the position of the point light source S as the origin, an angle φ (vertical angle) that makes the direction the y-axis, and a map that projects the direction onto the xz plane ( The light distribution characteristic of the point light source S is expressed by a set of an angle θ (horizontal angle) formed by a straight line) and the x axis, and the luminous intensity q is associated with each direction of the light beam L expressed by the set of the angle φ and the angle θ. Represents.

  Therefore, the light distribution characteristics of the point light source S are expressed using polar coordinates with the point light source S as the origin. The vertical angle φ has a range of [0 °, 180 °], and the horizontal angle θ has a range of [0 °, 360 °] around the y axis with the direction from the x axis to the z axis being positive. Have. For φ, the negative direction of the y-axis is 0 °, and the positive direction of the y-axis is 180 °. In Table 2, the vertical angle φ and the horizontal angle θ are set in steps of a fixed angle (for example, 5 °).

  The light distribution characteristics of the point light source S shown in Table 2 are default values. As described above, when the light distribution curve of the point light source S is deformed, the light distribution characteristics also change. The changed light distribution characteristic is stored in the storage unit 8.

  (3) When the light distribution characteristic of the selected point light source S is determined, the posture setting unit 4 applies the same light distribution characteristic to the other point light sources S as shown in FIG. That is, the same light distribution characteristic is set for each point light source S arranged in the outer peripheral region D1. In this state, the inner region D2 is surrounded by the superposition of the light distribution curves of the point light sources S. At this stage, as shown in Table 1, the angles (α, β, γ) of the optical axis Ax of each light source S are registered in the storage unit 8.

  (4) After the light distribution characteristic of the point light source S in the outer peripheral region D1 is set, the direction of the parallel light beam with respect to the inner region D2 is set. In order to determine the direction of the parallel light beam, first, the vertical angle of the light distribution characteristic of the point light source S obtained in (2) (the light distribution characteristic set based on the default values in Table 2 and stored in the storage unit 8) is determined. The vertical angle φ (where 0 ° ≦ φ ≦ 90 °) at which the value of q · cos φ obtained from φ and the luminous intensity q is maximized is obtained as the reference vertical angle φs. Further, the horizontal angle θ corresponding to the reference vertical angle φs is obtained as the reference horizontal angle θs.

  The reference vertical angle φs and the reference horizontal angle θs obtained as described above are stored in the storage unit 8, and are used as the direction of the parallel light beam in the inner region D2.

  (5) When the light distribution is determined for the outer peripheral area D1 and the inner area D2 as described above, it is possible to perform illumination calculation by setting the luminous intensity in the outer peripheral area D1 and the inner area D2, respectively. However, in this embodiment, in order to further reduce the calculation load, the range in which the light from the point light source S is used in the virtual space is limited.

  Specifically, only a light beam emitted outward from the light emitting region D0 of the light source and emitted in a negative direction in the y-axis direction from the light emitting region D0 of the light source is treated as an effective light beam. The light flux emitted inward of the light emitting area D0 and the light flux emitted in the positive direction in the y-axis direction from the light emitting area D0 are ignored as invalid.

  As shown in Table 2, the light distribution characteristics of the point light source S are represented by a set of a vertical angle φ, a horizontal angle θ, and a luminous intensity q. Therefore, the relationship between each side of the outer peripheral region D1 in the horizontal direction θ is evaluated. Then, it can be determined whether or not the light beam is emitted outward from the light emitting region D0, and if the vertical direction φ is evaluated, the light beam emitted from the light emitting region D0 in the positive direction in the y-axis direction. It can be determined whether or not.

  First, in order to determine whether the light beam is emitted outward from the light emitting region D0, as shown in FIG. 13A, each side of the outer peripheral region D1 of the light source is given an orientation. Treated as a vector <Cn> (in the example shown, n = 1, 2, 3, 4), an outer product with a unit vector centered on each point light source S arranged in the outer peripheral region D1 is obtained. The vector <Cn> that gives the direction to each side of the outer peripheral region D1 has a positive direction as the clockwise direction when the light emitting region D0 is viewed from the positive direction in the y-axis direction. Further, as shown in FIG. 13B, the unit vector <Ua> is set within a range of [0 °, 360 °] in steps of a fixed angle (for example, 5 °) with the position of each point light source S as the center. Is done. The angle increment of the unit vector <Ua> is made to coincide with the angle increment defining the light distribution characteristic.

  Out of the outer product (<Cn> × <Ua>) of the vector <Cn> defined on each side of the outer peripheral region D1 and the unit vector <Ua> set around each point light source S, the unit vector <Ua> emits light If it faces the outside of the region D0, it becomes a positive direction in the y-axis direction, and if it faces the inside, it becomes a negative direction in the y-axis direction. The range of the horizontal angle θ in which the direction of the outer product is positive in the y-axis direction is used as the effective range.

  Here, for the point light source S at the apex position of the outer peripheral region D1, it is necessary to obtain both the angle at which the direction of the outer product changes from negative to positive and the angle at which the outer product changes from positive to negative. For the point light source S on the side, if one of the angle at which the direction of the outer product changes from negative to positive and the angle at which the direction changes from positive to negative is known, the direction of the outer product between the angle and the angle different by 180 ° is obtained. The positive side is the effective range of the horizontal angle θ. FIG. 13C shows the effective range of the horizontal angle θ for each light source S by hatching. The effective range [θi1, θi2] of the horizontal angle θ is registered in the storage unit 8 in association with the point light source S as shown in Table 1.

  When data representing the light distribution characteristics of the point light source S as shown in Table 2 is used as the horizontal angle θ, light emission at the position of each point light source S is possible if the light emitting region D0 is inclined with respect to the xz coordinate axis. It is necessary to correct the horizontal angle θ according to the inclination angle of the region D0.

  (6) In (5), the effective range is limited for the horizontal angle θ, but the effective range is limited for the vertical angle φ as follows. That is, from the relationship between the reference horizontal angle θs (0 ° ≦ θs <360 °), the reference vertical angle φs (0 ° ≦ φs ≦ 180 °), and the effective range of the horizontal angle θ obtained in (5), the vertical angle φ The effective range is determined under the following conditions (a) and (b). The effective range is registered in the storage unit 8 as the effective range of the vertical angle in Table 1.

  (A) When the reference horizontal angle θs is included in the effective range of the horizontal angle θ (that is, when the direction of the optical axis Ax of the point light source S is outward), the effective range of the vertical angle φ is φs A region of ≦ φ ≦ 90 ° is used.

  (B) When the reference horizontal angle θs is not included in the effective range of the horizontal angle θ (that is, when the direction of the optical axis Ax of the point light source S is inward), the region where the horizontal angle θ is in the effective range The effective range of the vertical angle φ is set to 0 ° ≦ φ ≦ 90 ° for the region outside the light emitting region D0, and the vertical angle φ is set for the region where the horizontal angle θ is not in the effective range (region inside the light emitting region D0). Is set to 0 ° ≦ φ ≦ φs.

  In addition, since the surface light source assumes the case where a light beam is emitted only from one surface, the upper limit of the vertical angle φ is 90 °. Depending on the shape of the light source, the light beam may be emitted even when the vertical angle φ is larger than 90 °. However, in this embodiment, the light beam in the region where the vertical angle φ exceeds 90 ° is not used.

  When the effective area of the horizontal angle θ is determined as shown by the shaded area in FIG. 14A, the effective area of the vertical angle φ becomes as shown by the shaded area in FIG. . Further, when the effective area of the horizontal angle θ is determined as indicated by the shaded area in FIG. 15A, the effective area of the vertical angle φ is as indicated by the shaded area in FIG. become. In summary, for the vertical angle φ, the shaded portion on the left side of FIG. 16 is in the effective range under the condition (A), and the shaded portion on the right side in FIG. 16 is in the valid range under the condition (B). The effective range [φi1, φi2] of the vertical angle φ is registered in the storage unit 8 in association with the point light source S as shown in Table 1. That is, only the light beam in the shaded area in FIG. 16 is used for the illumination calculation.

  (7) When the effective range of the horizontal angle θ and the vertical angle φ is determined for each point light source S, the ratio of the light flux of each point light source S arranged in the outer peripheral region D1 is obtained before determining the light flux. Therefore, for each point light source S, the effective luminous flux Ei obtained by summing the luminous intensity in each effective range is obtained by using the light distribution characteristics as shown in Table 2. Further, the total luminous flux Et is obtained by summing the luminous intensity when the effective range is not set for the point light source S. The total light flux Et uses the same value for each point light source S. The effective light flux Ei and the total light flux Et are values obtained by adding the luminous intensity over a predetermined range, and thus correspond to the light flux.

  Since the ratio of the effective light beam Ei to the total light beam Et is a measure of the light beam of each point light source S, it is stored in the storage unit 8 as the light beam ratio in Table 1.

  When the shape of the light source is determined as described above, the arrangement position of the point light source S in the outer peripheral region D1, the light distribution characteristic of each point light source S, the direction of the parallel light beam in the inner region D2, and the point light source S The range of luminous flux to be used and the luminous flux ratio among the radiating luminous flux are obtained. Therefore, if the absolute value of the light flux is determined for the light flux emitted from each point light source S and the parallel light flux of the inner area D2, the characteristics of the light emission area of the light source are determined, and the illumination calculation becomes possible.

  If the effective range of the light flux emitted from the point light source S is not defined, the above-described procedures (4) to (7) can be omitted.

3. As described above, when the light distribution characteristic of each point light source S arranged in the outer peripheral area D1 and the direction of the parallel light flux in the inner area D2 are determined in the direction setting section 6, as shown in FIG. In the unit 7, the light intensity of the point light source S is set in order to perform illumination calculation in the virtual space. In the light beam allocating unit 7, the required light beam E is distributed and set to each point light source S and the inner region D2 in the outer peripheral region D1 according to the following procedure. The luminous flux E can be given to the luminous flux allocating section 7 by the user operating the input unit 1, and the light emission of the light source is based on the data of the light distribution characteristics relating to one point light source S shown in Table 2. The light flux of the entire region D0 may be calculated, and the calculated value may be used as a default.

(1) The total luminous flux E radiated from the light emitting region D0 of the light source is distributed to each point light source S and the inner region D2 of the outer peripheral region D1. Here, the following equation is used so that the total luminous flux in the outer peripheral area D1 and the total luminous flux in the inner area D2 are distributed one-to-one.
E = x (total luminous flux in the outer peripheral area) + x (total luminous flux in the inner area)
Total luminous flux in the outer peripheral area = ΣEi
Total luminous flux in the inner region = A × q0 / 4π
Where x is the intensity magnification, Ei is the effective light flux for each point light source S, q0 is the maximum light flux of the point light source S (light flux c corresponding to the reference horizontal angle θs and the reference vertical angle φs), and A is the area of the light emitting region D0. It is.

  Due to the above setting, the direction of the maximum luminous intensity q0 of the point light source S coincides with the direction of the parallel light flux of the inner region D2, so that the light beam emitted from the point light source S provided in the outer peripheral region D1 and the inner region D2 are parallel. By setting the luminous flux of the light beam to 1: 1, it is possible to prevent a boundary due to the difference in luminous flux between the outer peripheral area D1 and the inner area D2.

  (2) The effective luminous flux Ei for each point light source S is different for each point light source S, and the total luminous flux in the outer peripheral region D1 is xΣEi. In other words, the value obtained by multiplying the effective light beam Ei within the effective range of each point light source S by the intensity magnification x becomes the set value of the light beam of each point light source S. The intensity magnification x is set for the effective luminous flux Ei within the effective range obtained from the light distribution characteristics of the point light source S shown in Table 2. The point light source S having the light quantity xEi obtained in this way is arranged in the outer peripheral area D1, and it is assumed that light is radiated from the effective range for each point light source S, so that the entire outer peripheral area D1 becomes a light flux of xΣEi. Become. In addition, if the effective range is not prescribed | regulated for each point light source S, the light beam radiated | emitted from the point light source S of the outer periphery area | region D1 will become mutually equal.

  (3) The luminous flux per unit area in the parallel light flux of the inner region D2 is set to be equal to the luminous flux per unit area in the direction of the maximum luminous intensity q0 of each point light source S arranged in the outer peripheral region D1, When the luminous intensity per unit area is obtained from the maximum luminous intensity q0 in the point light source S, q0 / 4π is obtained. Therefore, when the area A of the inner region D2 is multiplied by q0 / 4π, the total luminous flux of the inner region D2 is calculated as A × q0 / 4π. Therefore, x · A · q0 / 4π becomes the light flux in the inner region D2 after the light flux is distributed.

  By setting the luminous fluxes of the outer peripheral area D1 and the inner area D2 in the above relationship, the luminous flux per unit area of the parallel light flux emitted from the inner area D2 and the unit area of the point light source S as shown in FIG. The light flux in the virtual space is set so that the brightness boundary between the point light source S in the outer peripheral area D1 and the inner area D2 does not occur. It becomes possible to form.

  After setting the light distribution characteristics and light flux of the light emitting region D0 for the outer peripheral region D1 and the inner region D2 as described above, the position and orientation of the light emitting region D0 are adjusted in the virtual space, and the light source is adjusted as necessary. Readjust the emitted light beam. When the light beam is readjusted, the intensity magnification multiplied by the point light source S and the inner region D2 in the outer peripheral region D1 is set to x (Ep / Ev using the relationship between the total light beam Ev before adjustment and the total light beam Ep after adjustment. ), And recalculation at the light beam assigning unit 7 is not necessary.

  In addition, when the position and orientation of the light source are adjusted, the change is commensurate with the change in the set value of the light emitting region D0 by reflecting the point light source S arranged in the outer peripheral region D1 and the parallel light flux of the inner region D2 respectively. I do. When the user uses the input unit 1 to adjust the position and orientation of the light source, the user can only adjust the light emitting area D0, and the adjustment for each point light source S and the parallel light flux is not based on a user instruction. Done automatically.

  When changing the light distribution characteristic of the light source, the light distribution characteristic of the point light source S arranged in the outer peripheral region D1 is newly set, the reference vertical direction φs of the point light source S is set, and then the direction of the parallel light bundle is adjusted. Repeat steps such as luminous flux distribution. However, when the position of the point light source S and the direction of the optical axis are already determined, and the effective range may be the same as before the change of the light distribution characteristics, the luminous intensity, the luminous flux, etc. that need to be changed according to the light distribution characteristics Only the values need to be recalculated, and the calculation load associated with the change in the light distribution characteristics of the light source is reduced.

  In order to change the light distribution characteristics of the light source, a property dialog is displayed on the screen of the monitor device 11, and the property dialog is popped up only when the light distribution characteristics of the light source is changed. Make sure that data can be entered. When changing the shape of the light source, the procedure from the creation of the shape of the light source is repeated. In addition, when a plurality of the same light sources are arranged in the virtual space or when only the light distribution characteristics of the light sources are changed, an appropriate name is given to the data set for the light sources and the data is stored in the storage unit 8 in a lump. Just keep it.

4). Other operation examples a. In the case of the line light source, the case where the light source is a surface light source has been exemplified in the configuration example described above, but the aspect ratio of the light source is a predetermined value (for example, 30: 1) or more and the short side has a predetermined dimension (for example, 2 [cm]) or less, the light source is substantially regarded as a linear light source, and is not separated into the outer peripheral region D1 and the inner region D2, but along the longitudinal direction in the light emitting region D0 of the light source as shown in FIG. Point light sources S may be arranged on the center line Lc. The intervals at which the point light sources S are arranged are such that the point light sources S are arranged at equal intervals, and the difference between the interval and a predetermined dimension (for example, 5 [cm]) is equal to or less than a specified value (for example, 5 [mm]). Set as follows.

  This process is the same as the process of setting an interval when the point light source S is arranged on the shortest side of the light source in the optimization unit 3. That is, the processing when the light source is a surface light source can be applied to the case where the light source is a line light source. When the light source is a line light source, no effective range for the horizontal angle θ is set for each point light source S. Therefore, the calculation load is not reduced by limiting the effective range, but the calculation load can be reduced by expressing the light distribution characteristics with the point light source S.

  When the light source is a line light source, if the short side is equal to or smaller than the predetermined dimension, the length dimension of the center line Lc and the long side along the longitudinal direction may be treated as an equal dimension. In addition to arranging the point light source S on the center line Lc, the point light source S may be arranged on one long side. That is, the optimization unit 3 is not intended to arrange the point light sources S in the outer peripheral region D1 at equal intervals, but is arranged so that it can be regarded as one light source without increasing the calculation load. Therefore, it is not essential that the point light source S has a symmetrical arrangement with respect to the light emitting region D0, and an arrangement in which illumination calculation with less error is possible while reducing the calculation load is permitted. It is.

b. In the case where the light emitting areas of the light source are both front and back sides In the configuration example described above, the example in which the light emitting area D0 is provided only on one surface of the light source has been described, but the light flux is emitted in the positive direction in the y-axis direction (the vertical angle is 90). The above-described technique can also be employed in the case of radiating a light beam in the range of ° to 180 °.

  That is, as shown in FIG. 19, for the light emitting region D0, a lower range Dw where the vertical angle φ is 0 ° ≦ φ ≦ 90 ° and an upper range Up where the vertical angle φ is 90 ° <φ ≦ 180 ° The light distribution characteristics are set separately. The set light distribution characteristics are stored in the storage unit 8 for the lower range Dw and the upper range Up, respectively. The reference horizontal angle θs and the reference vertical angle φs are also obtained from the lower range Dw and the upper range Up, respectively. Thereafter, for the lower range Dw and the upper range Up, the direction of the parallel light flux, the setting of the effective range, and the setting of the luminous flux are performed, respectively.

  Note that the reference vertical angle φs of the point light source may be different between the lower range Dw and the upper range Up. In the lower range Dw, the vertical angle φ (where 0 ° ≦ φ ≦ 90 °) at which the value of q · cos φ is maximum is obtained as the reference vertical angle φs, and in the upper range Up, the vertical angle at which q · cos φ is minimum φ (where 90 ° <φ ≦ 180 °) is determined as the reference vertical angle φs.

Further, regarding the setting of the luminous flux, since the upper range Up and the lower range Dw are combined to form the total luminous flux in the light emitting area D0, when setting the light intensity of the light source, the total luminous flux E in the luminous area D0 is It is expressed by the following formula.
E = x1Σ (total luminous flux in the outer area of the lower range) + x1 (total luminous flux in the inner area of the lower range) + x2Σ (total luminous flux in the outer circumferential area of the upper range) + x2 (total luminous flux in the inner area of the upper range)
Total luminous flux in the outer peripheral area of the lower range = ΣE1i
Total luminous flux in the inner region of the lower range = A × q10 / 4π
Total luminous flux in the outer peripheral area of the upper range = ΣE2i
Total luminous flux in the inner region of the upper range = A × q20 / 4π
However, x1 is an intensity magnification applied to the lower range Dw, x2 is an intensity magnification applied to the upper range Up, E1i is an effective luminous flux for each point light source S in the lower area, and E2i is an effective intensity for each point light source S in the upper area. Q10 is the maximum luminous flux of the point light source S in the lower range Dw, q20 is the maximum luminous flux A of the point light source S in the upper range Up, and the area of the light emitting region D0. E1i and E2i are effective luminous fluxes for each point light source S.

DESCRIPTION OF SYMBOLS 1 Input part 2 Shape change part 3 Optimization part 4 Arrangement | positioning / attitude setting part 5 Point light source assignment part 6 Direction setting part 7 Light flux assignment part 8 Storage part 9 Calculation part 10 Modeling part BB Bounding box D0 Light emission area D1 Outer peripheral area D2 Inside Area G Grid point S Point light source T Reference shape

Claims (7)

  A lighting simulator that evaluates the lighting environment by creating a virtual space equivalent to the real space for a three-dimensional lighting space and performing a lighting calculation in the virtual space, and defines the information and light source for constructing the virtual space And dividing the light emitting area of the light source arranged in the virtual space into an outer peripheral area over the entire outer periphery of the light emitting area and an inner area surrounded by the outer peripheral area. And a modeling unit that expresses the light flux emitted from the light emitting area of the light source by the light flux emitted from the point light source arranged in the outer peripheral area and the parallel light flux emitted from the inner area. A lighting simulator comprising:   The illumination simulator according to claim 1, wherein the modeling unit employs, for illumination calculation, a light beam emitted outward from the light emitting region among light beams emitted from the point light source.   The lighting simulator according to claim 1, wherein the modeling unit includes a shape changing unit that deforms the light emitting region by operating the input unit.   The modeling unit includes a storage unit that stores in advance a reference shape that is a basic shape of the light emitting region and includes a plurality of lattice points, and the shape changing unit is a bounding box that is a circumscribed rectangle of the reference shape 4. The illumination simulator according to claim 3, wherein an operation of deforming the reference shape by deforming the reference shape and an operation of deforming the reference shape by moving lattice points provided in the reference shape are possible.   The said modeling part is equipped with the optimization part which determines the position of a point light source according to the shape of the said outer periphery area | region so that the arrangement space | interval of the said point light source may be equalized, The any one of Claims 1-4 characterized by the above-mentioned. The lighting simulator according to claim 1.   The modeling unit includes an arrangement / posture setting unit that determines light distribution characteristics by operating the input unit for one of the point light sources in the outer peripheral region, and a light distribution determined by the arrangement / posture setting unit for the remaining point light sources. The illumination simulator according to claim 1, further comprising a point light source allocating unit that applies the characteristics.   The modeling unit automatically distributes the light flux between the outer peripheral area and the inner area so that there is no boundary between the light flux of the point light source arranged in the outer peripheral area and the light flux of the parallel light flux emitted from the inner area. The illumination simulator according to any one of claims 1 to 6, further comprising a light beam allocating unit that distributes the light to the light simulator.

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