Patent Document ID: 8325185
Application ID: 12312700
Patent Flag: 1

Claim One:
1. A non-transitory computer-readable recording medium which stores a rendering program for rendering a sterical model that is created beforehand in a virtual three-dimensional space, the program causing a computer to function as: a model acquisition portion for acquiring the sterical model of a certain object that is created beforehand within a virtual three-dimensional space by using modeling software; a texture acquisition portion for acquiring a texture of a fabric which has height information representing the shape of a surface of the fabric and fiber direction information indicating a fiber direction of a yarn configuring the fabric, and which is attached to a surface of the sterical model; a rendering portion for rendering the sterical model by using the texture and a reflection function expressing an energy of reflected light of the yarn that corresponds to a ray direction, an eye direction and the fiber direction represented by the fiber direction information, the directions being in the virtual three-dimensional space; a reflection property acquisition portion for acquiring a reflection property of an actual yarn that is obtained by measuring an energy of reflected light of the actual yarn after changing the ray direction and the eye direction and; and a correction portion for correcting the reflection function so that an error between the reflection property acquired by the reflection property acquisition portion and the energy of the reflected light obtained from the reflection function becomes minimum, wherein the rendering portion renders the sterical model by using the reflection function corrected by the correction portion, the reflection function includes specular reflection component representing an energy of specular reflected light of the yarn, a first diffuse reflection component representing an energy of diffuse reflection light, which is taken into account for the fiber direction of the yarn, of the diffuse reflection light of the yarn, and a second diffuse reflection component representing an energy of diffuse reflection light, which is not taken into account for the fiber direction of the yarn, of the diffuse reflection light of the yarn, the specular reflection component includes a variable part defined by the ray direction, the eye direction and the fiber direction, a specular reflection coefficient related to the variable part, and a glossiness coefficient representing a spread of a distribution of an energy of specular reflected light, the first diffuse reflection component includes a variable part defined by the ray direction and the fiber direction, and a first diffuse reflection coefficient related to the variable part, the second diffuse reflection component includes a variable part defined by the ray direction and a normal direction of the yarn, and a second diffuse reflection coefficient related to the variable part, and wherein the correction portion calculates at least any one coefficient of the specular reflection coefficient, the glossiness coefficient, the first diffuse reflection coefficient and the second diffuse reflection coefficient so that the error between the reflection property acquired by the reflection property acquisition portion and the energy of the reflected light obtained from the reflection function becomes minimum, the texture has fiber density information representing the density of fibers configuring a yarn subjected to a napping treatment, the rendering portion corrects the glossiness coefficient such that a distribution of the energy of the specular reflected light spreads out more in a section where the fiber density information is less available, and the rendering portion corrects the glossiness coefficient p by using an equation: p=p·d 2 where the value p represents the glossiness coefficient of the specular reflection component, the value p′ represents the corrected glossiness coefficient and the value d represents the fiber density information.