翻訳と辞書 Words near each other ・ Reflets dans l'eau ・ ReFLEX ・ Reflex ・ Reflex (building design software) ・ Reflex (disambiguation) ・ Reflex (game show) ・ Reflex (group) ・ Reflex (magazine) ・ Reflex (novel) ・ Reflex anal dilation ・ Reflex arc ・ Reflex asystolic syncope ・ Reflection formula ・ Reflection group ・ Reflection high-energy electron diffraction ・ Reflection lines ・ Reflection loss ・ Reflection map ・ Reflection mapping ・ Reflection nebula ・ Reflection of Joey's Live ・ Reflection of Something ・ Reflection principle ・ Reflection principle (disambiguation) ・ Reflection principle (Wiener process) ・ Reflection Riding Arboretum and Botanical Garden ・ Reflection seismology ・ Reflection symmetry ・ Reflection theorem ・ Reflectional receiver Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Reflection lines ： ウィキペディア英語版 Reflection lines Engineers use reflection lines to judge a surface's ''quality''. Reflection lines reveal surface flaws, particularly discontinuities in normals indicating that the surface is not $C^2$. Reflection lines may be created and examined on physical surfaces or virtual surfaces with the help of computer graphics. For example, the shiny surface of an automobile body is illuminated with reflection lines by surrounding the car with parallel light sources. Virtually, a surface can be rendered with reflection lines by modulating the surfaces point-wise color according to a simple calculation involving the surface normal, viewing direction and a square wave environment map. == Mathematical Definition == Let us consider a point $p$ on a surface $M$ with (possibly non-unit length) normal $n$. If an observer views this point from infinity at a incoming direction $v$ then the reflected view direction $r$ is: $r\; =\; (2/|n|^2)((n\; \backslash cdot\; v)n\; -v).$ For reflection lines we consider repeated infinite, non-dispersive light sources parallel to some line $a$ and therefore perpendicular to a plane $P$. Define the vector $d$ to be the reflection direction $r$ projected onto the plane $P$: $d\; =\; r\; -\; (r\; \backslash cdot\; a)a$ and similarly let $v\_a$ be the unit viewing direction projected onto $P$: $v\_a\; =\; \backslash hat/|\backslash hat|,\; \backslash hat\; =\; v\; -\; (v\; \backslash cdot\; a)a$ Finally, define $a^\backslash perp$ to be the direction lying in $P$ perpendicular to $a$ and $v\_a$: $a^\backslash perp\; =\; a\; \backslash times\; v\_a$ Then the *reflection line function * $\backslash theta(p):\; M\; \backslash rightarrow\; (-\backslash pi,\backslash pi]$ is a scalar function mapping points on the surface to angles between $v\_a$ and the projected reflected view direction $d$: $\backslash theta\; =\; \backslash arctan$ where $arctan(y,x)$ is the atan2 function producing a number in the range $(-\backslash pi,\backslash pi]$. Finally, to render the reflection lines positive values $\backslash theta>0$ are mapped to a light color and non-positive values to a dark color.〔Gingold et al. "Shape Optimization Using Reflection Lines"〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Reflection lines」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.