JP3528584B2 - Brightness distribution display system - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates, the table Shimesuru cis <br be virtually determined luminance distribution when viewed from a certain viewing direction when illuminated by a predetermined light source to an object such as an automobile /> is relates to the Te-time.

[0002]

2. Description of the Related Art It is important to evaluate the surface quality when designing the outer shape of an automobile with a CAD device or the like.
There is a method for checking highlight lines as described in Japanese Patent No. 6818. The highlight line is a gradation of brightness (luminance distribution). For example, the point at infinity is used as the light source, and the angle formed by the vector in the direction of the light source and the normal vector of each part of the surface, that is, the position where the incident angle is equal, is the predetermined incident angle interval. It was tied with.

[0003]

However, since the line-of-sight direction and the characteristics of the material have not been taken into consideration in the past, for example, the appearance (luminance distribution) of the line-of-sight (brightness distribution) differs depending on the line-of-sight direction such as a metallic coating surface or a pearl / mica coating surface Has a problem that an accurate luminance distribution cannot always be obtained. That is, if it is a uniform diffusion surface that reflects light uniformly in all directions, such as rubber or black ink, its brightness distribution depends only on the angle of incidence, so there is no problem with the conventional method, but in actual car painting Since the surface and the surface of most other substances are not uniform diffusion surfaces, the luminance distribution changes with the change of the line of sight,
Moreover, the changing tendency differs depending on the material.

The present invention has been made in view of the above circumstances, and an object thereof is to make it possible to more accurately obtain a luminance distribution.

[0005]

[0006]

[Means for Solving the Problems]
Therefore, a first invention is a brightness distribution display system that virtually obtains and displays a brightness distribution when viewed from a certain line-of-sight direction when an object is illuminated by a predetermined light source,
(a) a data storage device that stores luminance data using a variable angle and an incident angle, which are angular differences between the regular reflection direction and the line-of-sight direction, as parameters, and (b) the positions of the target object and the light source and the line-of-sight direction. Setting operation means that is operated to set the relative relationship, (c) based on the relative relationship and the surface shape data representing the surface shape of the object, the incident angle and the divergence angle at each part of the surface of the object. Angle calculation means to be obtained,
(d) a brightness distribution calculating means for obtaining the brightness distribution of the surface of the object from the brightness data based on the incident angle and the variation angle, and (e) visually displaying the brightness distribution calculated by the brightness distribution calculating means. While having a display device , (f) real
When the target object or the sample of the same surface condition as the target object
Incident obtained by illuminating light and measuring reflected light
The parameter is the wavelength λ and the variation angle α when the angle θ = 0 °.
By inputting the data of the spectral solid angle reflectance
And the incident angle θ = 0 ° according to a predetermined calculation formula.
The combined luminance Y ₀ is calculated using the variable angle α as a parameter, and
Before the luminance data DY ₀ representing the relationship between the luminance Y ₀ and deformation α
Equipped with a luminance data creating means to be stored in the data storage device
And, (g) the luminance distribution calculating means, the luminance Y = Y ₀ ×
It is characterized in that the luminance distribution is obtained based on the relationship of cos θ .

[0007]The second invention is that a predetermined light source is applied to an object.
Luminance distribution when viewed from a fixed line of sight when illuminated
Is a brightness distribution display system that virtually obtains and displays
hand, (a) A variable angle that is the angle difference between the specular direction and the line-of-sight direction.
And brightness data are stored with the incident angle as a parameter.
A data storage device, (b) Position and view of the object and light source
Setting operation that is operated to set the relative relationship with the line direction.
Means of work, (c) The relative relationship and the surface shape of the object
The surface of the object based on the surface shape data
Angle calculating means for obtaining incident angle and variable angle in each part
When, (d) Based on the angle of incidence and the angle of variation, the luminance data
Brightness distribution to obtain the brightness distribution on the surface of the object from the
Arithmetic means, (e) Calculated by the brightness distribution calculation means
While having a display device that visually displays the brightness distribution,
(f) Of the actual object or of the same surface condition as that object
It is obtained by illuminating the sample with light and measuring the reflected light.
When the incident angle θ is a predetermined angle x other than 0 °, the wavelength λ and
And specular solid angle reflectance data with the variable angle α as a parameter
By inputting,
And the luminance Y when the incident angle is θ = x _x Is the variable angle α
And the brightness Y _x Which represents the relationship between
Degree data DY _x Is stored in the data storage device.
Equipped with data creation means, (g) The brightness distribution calculating means
Luminance Y = (Y _x / cos x) x cos Based on θ
Characterized in that the brightness distribution is obtained by.

[0008]

[0009]

According to such a brightness distribution display system , the brightness data is created by actually measuring the reflected light and using the deviation angle and the incident angle as parameters, and the positions of the object, the light source, and the line-of-sight direction are compared. The angle of incidence and the angle of variation on each part of the surface of the object are calculated based on the relative relationship, and the luminance distribution on the surface of the object is calculated from the luminance data based on the angle of incidence and the angle of variation. Therefore, a more accurate luminance distribution can be obtained.

According to the first aspect of the invention, if the spectral solid angle reflectance is measured with a spectrophotometer and the measurement data is input, the luminance data creation means automatically produces the luminance data DY.
_{Since 0} is created and stored in the data storage device, the burden on the operator is reduced, and even when the brightness distribution is examined for an object of a new material for which the brightness data DY ₀ is not stored in the data storage device, Brightness data DY ₀
Can be created to obtain the luminance distribution.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Here, since the change characteristics of the brightness due to the change of the incident angle and the change of the angle are different depending on the surface material including the color, the brightness data is different for each object having the different surface material including the color. However, when the influence of color is relatively small, the influence of color is ignored and luminance data is created for each material. The brightness may be obtained using the brightness data. In addition, when obtaining the brightness distribution and the like using a plurality of types of light sources, it is desirable to create brightness data for each type of light source (emission wavelength characteristics, etc.) in advance. Differences in color and types of light source may be dealt with by a correction map for correcting basic luminance data.

Further, the angle of deviation is an angle between the specular reflection direction and the line-of-sight direction. The conical generatrix angle = the angle of the conical generatrix with the specular reflection direction as the center is the same, so the same. Even with a variable angle, the brightness may differ depending on the positional relationship with the specular reflection direction. In that case, for example, the eccentric direction located in the plane (incident surface) including the regular reflection direction and the surface normal direction is used as a reference position, and the rotation angle around the regular reflection direction from the reference position is used as a parameter to further finely tune the brightness. Data or a correction map may be created.

[0013]

[0014] The relative relationship between the position and the viewing direction of the object and the light source can be set arbitrarily by setting the operating means, a light source position, can also be configured to be set to a predetermined fixed position in, setting operation unit is not limited as long as to set at least one of the relative relationship.

In calculating the brightness distribution, for example, the brightness of each part of the surface of the object may be obtained and the equal brightness points may be connected at a predetermined brightness interval. In the case of creating lines, it is also possible to obtain a variation angle having a predetermined luminance for each equal incident angle line and connect the variation points to create the equal luminance line. It is also possible to create an iso-intensity line by creating an equi-angular line at a predetermined interval and then obtain an incident angle with a predetermined brightness for each of the angle lines and connect the incident angle points.

The display device for visually displaying the luminance distribution is, for example, an image display such as a liquid crystal panel, a CRT or the like, which displays the difference in luminance by an isoluminance diagram, color-coded or gray-scale, or paper. Ru der such as a printer to print to.

The present invention is preferably used for checking the luminance distribution at the time of designing the shape of an automobile composed of a free-form surface, but the luminance at the time of designing the shape of various objects regardless of the presence or absence of the free-form surface. It can be used in various modes such as a distribution check or a virtual display of a luminance distribution when a virtual object or an existing object is illuminated by a predetermined light source. Regarding the light source, it is common to obtain the incident angle and the angle of variation as parallel light at the point at infinity, but it is relatively close to the target object, for example, when creating a brightness distribution when a spotlight is applied in the studio. It is also possible to set a point light source at a position and obtain the incident angle or the variable angle as diffused light to calculate the brightness.

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram illustrating the basic configuration of a luminance distribution display system 10 according to an embodiment of the present invention, which is used when designing the shape of an automobile body and is connected online. Computer device 1
2 and the external storage device 14, and the external storage device 1
A large number of computers other than the computer device 12 are connected to the computer 4. The computer device 12 is a microcomputer, and a CPU connected by a data bus line.
And the like, and a main storage device 18 such as a RAM or a ROM.
Various arithmetic processes are performed according to a program stored in the main storage device 18 in advance, and a luminance data creation function, a luminance distribution calculation / display function, a CAD function, and the like are executed. The computer device 12 is a terminal of a network, and has only a CAD function, a CAD function and a brightness distribution calculation / display function, a brightness data creation function, or a CAD function, a brightness data creation function, depending on the work content.
Various computer devices 12, such as those having all the functions of calculating and displaying the brightness distribution, are connected, but at least the CAD function, the function of creating brightness data, and the calculation and display of the brightness distribution as the entire network. It just needs to have the function.

The computer device 12 shown in FIG.
Has a CAD function, a luminance data generating function, and a luminance distribution calculation / display function. The main memory 18 stores a program for that purpose.
Each function is executed by performing signal processing according to the flowcharts shown in FIGS. This main memory 18
Corresponds to a program recording medium. The central processing unit 16 is also input by a CRT that displays an image of the design result of the vehicle body shape and the brightness distribution when the vehicle body is irradiated with light, a display device 20 such as a liquid crystal panel, and an operator (CAD designer). A keyboard 22, a dial 24, a tablet 26, etc., as an input device for performing operations are connected,
If necessary, a spectrophotometer 30 may be used when creating brightness data.
Are connected. In addition, the network controller 28
Is for controlling data output such as file transfer by connecting to a workstation or machine tool.

In FIG. 2, in step S1, CAD
With the function, the surface shape data representing the surface shape of the vehicle body is created or corrected according to the operation of the keyboard 22 by the operator. The surface shape data represents the surface shape (free-form surface) of the vehicle body by a curved surface expression or the like, but it does not necessarily have to include the entire vehicle body, and it is usually designed by dividing it into a plurality of parts such as a door panel. . Next step S2
Then, the surface quality of the surface shape represented by the surface shape data created in step S1 is checked, and in step S3, according to the result of the operator's judgment as to whether the surface quality is OK, that is, the input operation is OK. In case of (YES), step S4 is executed, but in case of NG (NO), step S4 is executed.
Repeat 1 or less. It is also possible to classify the surface quality check items into a plurality of items, and to perform some of them automatically by a computer. In step S4, a series of signal processing is ended when the operation is finished (YES) in accordance with the operator's input operation as to whether or not the work for producing the surface shape data is finished, but when the work for producing the surface shape data is continued ( NO)
Repeats step S1 and subsequent steps.

The surface quality check in step S2 is for checking the luminance distribution, and is specifically executed according to the flowchart of FIG. In step R1 of FIG. 3, the material (classification) and color of the body painting surface such as solid, metallic, and pearl mica are set by the operator using the keyboard 22 or the like. Specifically, it is input by a paint color symbol indicating the material and color. In step R2,
It is determined whether or not the input luminance data DY ₀ of the paint color symbol exists in the database of the external storage device 14, and if it is in the database, the steps R4 and thereafter are immediately executed. If it is not in the database, the step R3 is executed. Luminance data DY ₀ is created. The external storage device 14 corresponds to the data storage device for storing the luminance data, portions for performing the steps R3 of a series of signal processing by Chuo processor 16 corresponds to the luminance data generating means. When the brightness data DY ₀ is created and stored for each type of light source, the type of light source may be set in step R1.

In step R3, signal processing is performed according to the flowchart shown in FIG. 4, and first, step R3-1.
A display indicating that the brightness data should be created is displayed on the display device 20.
Is displayed in. As a result, the operator prepares a sample coated with the coating color of the coating color code input in step R1,
The spectral solid angle reflectance R is measured by the spectrophotometer 30.
In the present embodiment, as shown in FIG. 6, light is emitted perpendicularly to the surface of the sample 32 by a predetermined light source, and the reflected light is detected by the optical sensor while changing the variation angle α (°). The reflectance R when θ = 0 ° is the wavelength λ (nm)
And the angle of variation α (°) is measured as a parameter. The variable angle α is the angle difference between the specular reflection direction in which the reflection angle is equal to the incident angle θ and the light detection direction, and in this case is the inclination angle from the direction perpendicular to the surface of the sample 32, and the reflectance R is It is a ratio to the reflected light on the diffuse reflection surface. As the light source, for example, D6 according to the CIE (International Commission on Illumination) standard
5 is used, but if the light source for creating the luminance distribution to check the surface quality can be set arbitrarily,
It is desirable to use the same light source. Note that the sample 32 having a flat surface is easy to handle.

7 to 9 show an example of the spectral solid angle reflectance R thus measured, FIG. 7 shows the case of the coating color symbol "3E5" which is an example of the solid, and FIG. In the case of the coating color code “8E9” which is an example of mica, FIG.
Shows the case of the coating color code “199” which is an example of metallic. Further, FIG. 10 is a diagram showing a comparison of the reflectance characteristics at the wavelength λ = 550 nm. In any coating color, the reflectance R greatly changes with the angle of deviation α as a parameter, and the change depending on the coating color. It can be seen that the characteristics are different. The paint color code "3E
"5", "8E9", and "199" are all in-house symbols of Toyota Motor Corporation.

Returning to FIG. 4, in step R3-2, the data of the spectral solid angle reflectance R measured by the spectrophotometer 30 is read, and in step R3-3, the read data is used to obtain the following equation (1) ), The brightness Y ₀ when the incident angle θ = 0 ° is calculated at a predetermined constant angle change interval or a predetermined angle change interval arbitrarily set by the operator. As a result, as shown in FIG. 11, the variable angle α and the brightness Y ₀
Luminance data DY ₀ representing the relationship with, that is, Y ₀ = f
(Α) is obtained, and the brightness data DY ₀ is stored in the database of the external storage device 14 together with the paint color symbol by an arithmetic expression or a data map having the variable angle α as a parameter. Luminance data DY for this incident angle θ = 0 °
₀ presupposes the relationship of the following expression (2), and substantially corresponds to the brightness data of the brightness Y with the variable angle α and the incident angle θ as parameters. I (λ) in the equation (1) is a light intensity characteristic of the light source such as the D65, y (λ) is a color matching function (visual sensitivity), and an integration section is a visible region from 350 nm to 800 nm. The color matching function y (λ) is defined by JIS Z81.
XYZ specified in 05-1982, No. 2026
One of the color-matching functions of the color system, which is a weighting function used when calculating tristimulus values (X, Y, Z in the XYZ color system) from the spectral distribution I (λ) of light, Y = k∫I (λ) y
(Λ) dλ (k: constant), officially "y"
A symbol with a horizontal bar "?" Is used above, but in this specification, "y" is used for convenience. The light intensity I
(Λ) may be appropriately selected and set according to the type of light source. Y ₀ = {100 / ∫I (λ) y− (λ) dλ} × ∫R (λ, α) I (λ) y− (λ) dλ (1) Y = Y ₀ × cos θ・ ・ (2)

Returning to FIG. 3, in step R4, the surface shape represented by the surface shape data created in step S1, in other words, the object to be irradiated with light is displayed as an image on the display device 20, and the surface shape and the light source are displayed. The relative relationship between the position and the line-of-sight direction is set by the operator using the keyboard 22 or the like. In this case, the line-of-sight direction is the direction perpendicular to the display screen of the display device 20, and the relative relationship between the line-of-sight direction and the surface shape is set by changing the posture of the surface shape on the screen. Further, the light source position is arbitrarily set, such as a point at infinity with a horizontal angle of 45 ° and an elevation angle of 45 ° from the line-of-sight direction, but a fixed position may be set in advance. When the brightness data DY ₀ is created for each type of light source, the type of light source is also set . Keyboard 22 or the like to be operated by the operator to set the relative relationship corresponds to the setting operation unit.

In step R5, the incident angle θ and the variation angle α at each part of the surface are obtained based on the relative relationship and the surface shape represented by the surface shape data created in step S1. That is, for example, as shown in FIG. 12, a large number of grids are formed by forming a lattice on the surface shape 34 represented by the surface shape data at a predetermined constant interval or a predetermined interval arbitrarily set by the operator. A sampling point (intersection point) P is set, and an incident angle θ and a variable angle α at the sampling point P are calculated from the geometrical relationship shown in FIG. Specifically, when the surface shape 34 is a free-form surface, the surface normal direction of each sampling point P is calculated to calculate the incident angle θ which is an angle between the surface point 34 and the light source direction, and the surface normal direction is sandwiched. Find the direction of specular reflection that is symmetrical to the light source,
It suffices to calculate a variation angle α which is an angle with the line-of-sight direction.
In FIG. 13, the line-of-sight direction is shown within the plane of incidence including the light incident direction and the specular reflection direction, but the line-of-sight direction and the plane of incidence are irrelevant and generally intersect the plane of incidence at the sampling point P. Direction . Portions for performing the steps R5 of the series of signal processing by Chuo processor 16 corresponds to the angle calculating means.

Then, in the next step R6, a luminance distribution on the surface shape 34 is created from the luminance data DY ₀ based on the incident angles θ and the variation angles α of the above-mentioned many sampling points P. Specifically, as shown in FIG. 5, first, in step R6-1, a constant incident angle interval that is predetermined based on the incident angle θ of the sampling point P, or an incident angle that is arbitrarily set by the operator. Equal incident angle lines Lθ _n at angular intervals
(N = 1, 2, ...) Is obtained using linear interpolation or the like. FIG. 14 (a) shows the equal incident angle line Lθ on the surface shape 34.
_n is in the created state.

In step R6-2, the equal brightness Y _m (m = _m ) is set at a predetermined brightness interval for each of the equal incident angle lines Lθ _n or at a predetermined brightness interval arbitrarily set by the operator. 1, 2, ...)
_{Calculate nm} . This is the relation Y = Y ₀ × cos of the equation (2).
From θ, the luminance Y _0m at the incident angle θ = 0 °, which is the luminance Y = Y _m on each equal incident angle line Lθ _n , is calculated according to the following equation (3), and the luminance data DY _0, that is, Y ₀ = f (α ) To its brightness Y
_It suffices to find a variation angle α _nm that satisfies ₀ = Y _0m . Θ _{n in} equation (3)
Is the incident angle of each equal incident angle line Lθ _n . Then, the position of the variation angle α _nm on each equal incident angle line Lθ _n is obtained by linear interpolation or the like based on the variation angle α of the sampling point P.
In FIG. 14B, the position (change point) of the change angle α _nm is plotted on each incident angle line Lθ _n , and the change point where m is equal is the position of equal brightness Y _m . Y _0m = Y _m / cos θ _n (3)

At step R6-3, each equal incident angle line Lθ is
_nInflection point α plotted above_nmOf which m is equal
Point, that is, brightness is Y_mInflection point α of_nmConnect the isoluminance lines
LY _mTo create. As a result, as shown in (c) of FIG.
Una isoluminance line LY_mThe luminance distribution can be obtained.

The portions for performing the steps R6 in the series of the signal process by Hisashi Naka processing unit 16 corresponds to the luminance distribution calculation means.

In step R7 of FIG. 3, the luminance distribution obtained in step R6 is displayed on the display device 20 as an isoluminance diagram as shown in FIG. 14C, or is color-coded according to the luminance. , An image is displayed on the display device 20 in gray scale. Then, the operator looks at this image display, checks the quality of the designed surface shape 34, and judges OK or NG.

Here, the brightness distribution display system of the present embodiment
10 is a database of the external storage device 14 for each type of coated surface.
Luminance data with the variable angle α stored in the source as a parameter
DY ₀By using the luminance component on the surface shape 34 that is the object.
Obtain the cloth with the variable angle α and the incident angle θ as parameters.
Since it looks like a line of sight even if it is not a uniform diffusion surface
A more accurate luminance distribution can be obtained according to the direction.

Further, in this embodiment, if the spectral solid angle reflectance R is measured by the spectrophotometer 30 and the measured data is input, the brightness data DY ₀ is automatically created, which imposes a burden on the operator. together is reduced, it can be obtained in the external storage device 14 even when examining luminance distribution for the object of a new material that luminance data DY ₀ is not stored, readily luminance distribution creates a luminance data DY ₀ .

Although the embodiment of the present invention has been described in detail with reference to the drawings, this is merely an embodiment,
The present invention can be implemented in various modified and improved modes based on the knowledge of those skilled in the art.

[Brief description of drawings]

FIG. 1 is a block diagram illustrating a basic configuration of a brightness distribution display system that is an embodiment of the present invention.

FIG. 2 is a flow chart explaining the basic operation of the embodiment of FIG.

FIG. 3 is a flowchart illustrating the specific content of step S2 in FIG.

FIG. 4 is a flowchart illustrating the specific content of step R3 in FIG.

FIG. 5 is a flowchart illustrating the specific contents of step R6 of FIG.

FIG. 6 is a diagram illustrating a measurement mode when measuring the spectral solid angle reflectance while changing the angle of variation α in step R3-2 of FIG. 4;

FIG. 7 is a diagram showing an example (solid) of the spectral solid angle reflectance measured in step R3-2 of FIG.

8 is a diagram showing another example (pearl mica) of the spectral solid angle reflectance measured in step R3-2 of FIG.

9 is a diagram showing still another example (metallic) of the spectral solid angle reflectance measured in step R3-2 of FIG. 4. FIG.

FIG. 10 is a diagram showing a comparison between the relationship between the spectral solid angle reflectance R and the angle of variation α in the examples of FIGS. 7 to 9.

11 is a luminance Y obtained in step R3-3 of FIG.
It is a figure which shows an example of the brightness | luminance data showing the relationship between ₀ and the change angle (alpha).

12 is a diagram illustrating a sampling point P set when performing step R5 of FIG.

FIG. 13 is a diagram illustrating an incident angle θ and a variable angle α calculated for each sampling point P in step R5 of FIG.

FIG. 14 is a diagram illustrating specific contents when creating a luminance distribution according to the flowchart of FIG.

[Explanation of symbols]

10: brightness distribution display system 12: Computer 14: Storage (data storage device) 16: central processing unit 18: main memory equipment 20: Display device 22: Keyboard (setting operation means) 32: Sample 34: surface shape (object) step R3: Brightness data creating means step R5: square calculating means step R6: Brightness distribution calculating means

Claims (2)

(57) [Claims] 1. A brightness distribution display system that virtually obtains and displays a brightness distribution when viewed from a certain line-of-sight direction when an object is illuminated with light from a predetermined light source. A data storage device that stores brightness data using a variable angle and an incident angle, which are angular differences from the direction, as parameters, and settings that are operated to set the relative relationship between the position of the object and the light source and the line-of-sight direction. An operating means, an angle calculating means for obtaining an incident angle and a divergence angle on each part of the surface of the object based on the relative relationship and surface shape data representing the surface shape of the object, and based on the incident angle and the angulation angle. Te and luminance distribution calculation means for obtaining a luminance distribution of the surface of the object from the luminance data, while having a display device for visually displaying the luminance distribution calculated by the luminance distribution calculating means, the actual A sample of the surface condition of the elephant compound or the object of the same quality
Incident obtained by illuminating light and measuring reflected light
The parameter is the wavelength λ and the variation angle α when the angle θ = 0 °.
By inputting the data of the spectral solid angle reflectance
And the incident angle θ = 0 ° according to a predetermined calculation formula.
The combined brightness Y ₀ is calculated using the angle of deviation α as a parameter, and
Wherein the luminance data DY ₀ representing the relationship between the degree Y ₀ and deformation α
Equipped with means for creating brightness data to be stored in the data storage device
Therefore, the brightness distribution calculating means calculates the relationship of brightness Y = Y ₀ × cos θ
The brightness distribution display system is characterized in that the brightness distribution is obtained based on . 2. An object is illuminated with light from a predetermined light source.
In this case, the brightness distribution when viewed from a fixed line of sight is virtually
A brightness distribution display system for obtaining and displaying, Deflection and incidence, which is the angular difference between the specular direction and the line-of-sight direction
Data that stores brightness data with corners as parameters
Storage device, Set the relative relationship between the position of the object and the light source and the line-of-sight direction
Setting operation means operated to Surface shape representing the relative relationship and the surface shape of the object
Angle of incidence on each part of the surface of the object based on the data
And an angle calculation means for obtaining a variable angle, From the brightness data based on the angle of incidence and the angle of variation,
Brightness distribution calculating means for obtaining the brightness distribution on the surface of the object, Visualize the brightness distribution calculated by the brightness distribution calculation means
While having a display device for displaying, For an actual object or a sample with the same surface condition as the object
Incident obtained by illuminating light and measuring reflected light
Wavelength λ and variation angle when the angle θ is a predetermined angle x other than 0 °
Input spectral solid angle reflectance data with α as parameter
Injects according to a predetermined calculation formula
Luminance Y when angle θ = x _x With the variable angle α as a parameter
Calculate the luminance Y _x Data that represents the relationship between
DY _x Luminance data stored in the data storage device
Equipped with means, The brightness distribution calculating means is configured to calculate brightness Y = (Y _x / cos x) x
cos The brightness distribution should be calculated based on the relationship of θ.
And a brightness distribution display system characterized by: