Design layer data creation device and method, and design simulation device

Patent metadata

Field	Value
Publication number	US-2016371880-A1
Application number	US-201414902151-A
Country	US
Kind code	A1
Filing date	Aug 5, 2014
Priority date	Aug 30, 2013
Publication date	Dec 22, 2016
Grant date	—

Abstract

There is provided a method and a device, each of which can improve the reproducibility of the appearance of an actual product. A design layer data creation device 100 includes: a measuring instrument 151 which measures a BRDF of a design layer 210 configured by a paint color layer 202 and a clear coat layer 201 ; and a calculation element 120 which creates design layer data on the basis of an approximate BRDF according to a BRDF model. The calculation element 120 defines the approximate BRDF by respectively obtaining coupling coefficients Ks 1 , Ks 2 , and Kd of a specular reflectance distribution function and a diffuse reflectance distribution function so as to approximate measured BRDF data.

First claim

1 . A design layer data creation device comprising:
a measuring instrument which measures reflectance distribution of a design layer configured by a paint color layer having color and formed on the surface of an object, and a transparent clear coat layer superimposed on the paint color layer to cover the paint color layer; and a calculation element which defines a reflectance distribution function according to a reflectance distribution model so as to approximate a measurement result of a reflectance distribution of the design layer, and creates design layer data that represents a property of the design layer on the basis of the reflectance distribution function, wherein the reflectance distribution model is a model which defines a reflectance distribution function representing the reflectance distribution of the design layer by using, as variables, an incident direction vector and a reflection direction vector of light at one point of the design layer, and the reflectance distribution function is defined by linear combination of: a specular reflectance distribution function that represents specular reflectance distribution for defining a specular reflection mode by using, as variables, the incident direction vector and the reflection direction vector of light at the one point of the design layer, and by changing at least one of brightness, hue and saturation of color at the one point of the design layer according to the reflection direction vector; and a diffuse reflectance distribution function that represents diffuse reflectance distribution for defining a diffuse reflection mode configured such that the incident direction vector and the reflection direction vector of light at one point of the design layer are used as variables, and such that, irrespective of the reflection direction vector, and at one point of the design layer, brightness, hue and saturation of color are constant, or the change rate of any of brightness, hue and saturation of color is smaller than the change rate of any of brightness, hue and saturation of the specular reflection mode, and the calculation element defines a reflectance distribution function of the design layer by obtaining a coupling coefficient of each of the specular reflectivity distribution function and the diffuse reflectance distribution function so as to approximate the measurement result of the reflectance distribution of the design layer.

2 . The design layer data creation device according to claim 1 , wherein
the reflectance distribution function uses, as variables, the incidence direction vector and the reflecting direction vector of light at one point of the design layer, and is a function given by a linear combination of a regular reflectance distribution function representing regular reflectance distribution defining a regular reflection mode in the clear coat layer, the specular reflectance distribution function, and the diffuse reflectance distribution function, and the calculation element obtains a coupling coefficient of the regular reflectance distribution function on the basis of a material physical property of the clear coat layer.

3 . The design layer data creation device according to claim 1 , wherein
the specular reflectance distribution function is configured by at least two functions of a first specular reflectance distribution function, and a second specular reflectance distribution function representing second specular reflectance distribution, and as coupling coefficients of the specular reflectance distribution function, the calculation element obtains a coupling coefficient of the first specular reflectance distribution function, and a coupling coefficient of the second specular reflectance distribution function.

4 . The design layer data creation device according to claim 1 , wherein
the calculation element obtains the coupling coefficients of the approximated specular reflectance distribution function and the approximated diffuse reflectance distribution function such that each error of the approximated specular reflectance distribution function and the approximated diffuse reflectance distribution function with respect to the measurement result by the measuring instrument is minimized.

5 . A design simulation device which is a device for simulating a design of a design layer configured by a paint color layer having color and formed on the surface of an object, and a transparent clear coat layer superimposed on the paint color layer to cover the paint color layer, the design simulation device comprising:
the design layer data creation device according to claim 1 which outputs design layer data representing a property of the design layer; a design layer data storage section which stores design layer data outputted by the design layer data creation device; a product data storage section which stores product data including shape data of a product; and an output unit which outputs a calculation result of the calculation element, wherein the calculation element creates image data of the product colored with paint, on the basis of the design layer data stored in the design layer data storage section, and on the basis of the product data stored in the product data storage section.

6 . A design layer data creation method comprising:
a measuring process in which reflectance distribution of a design layer, configured by a paint color layer having color and formed on the surface of an object, and a transparent clear coat layer superimposed on the paint color layer to cover the paint color layer, is measured as measurement result data of reflectance distribution of the design layer; a definition process in which a specular reflectance distribution function is configured such that specular reflectance distribution for defining a specular reflection mode is represented by using, as variables, an incident direction vector and a reflection direction vector of light at one point of the design layer, and by changing at least one of brightness, hue and saturation of color at one point of the design layer according to the reflection direction vector, in which a diffuse reflectance distribution function represents a diffuse reflectance distribution that defines a diffuse reflection mode configured such that the incident direction vector and the reflection direction vector of light at one point of the design layer are used as variables, and such that, irrespective of the reflection direction vector, and at one point of the design layer, brightness, hue and saturation of color are constant, or the change rate of any of brightness, hue and saturation of color is smaller than the change rate of any of brightness, hue and saturation of the specular reflection mode, in which coupling coefficients of the specular reflectance distribution function and the diffuse reflectance distribution function are respectively obtained so as to approximate a measurement result of the reflectance distribution of the design layer, and in which reflectance distribution of the design layer is defined by linearly combining the specular reflectance distribution and the diffuse reflectance distribution function by using each of the coupling coefficients; and a data creation process which creates design layer data representing a property of the design layer on the basis of the definition of the reflectance distribution.

Assignees

• Honda Motor Co Ltd

Inventors

• Ide Daisuke

Classifications

• G06F30/15

  Vehicle, aircraft or watercraft design · CPC title

• G06F30/20

  Design optimisation, verification or simulation (optimisation, verification or simulation of circuit designs G06F30/30) · CPC title

• G06T15/506 Primary

  Illumination models · CPC title

• G06F17/5009

  Physics · mapped topic

• G06F17/5095

  Physics · mapped topic