rotate.html 46 KB

123456789101112131415161718192021222324252627282930313233343536373839404142434445464748495051525354555657585960616263646566676869707172737475767778798081828384858687888990919293949596979899100101102103104105106107108109110111112113114115116117118119120121122123124125126127128129130131132133134135136137138139140141142143144145146147148149150151152153154155156157158159160161162163164165166167168169170171172173174175176177178179180181182183184185186187188189190191192193194195196197198199200201202203204205206207208209210211212213214215216217218219220221222223224225226227228229230231232233234235236237238239240241242243244245246247248249250251252253254255256257258259260261262263264265266267268269270271272273274275276277278279280281282283284285286287288289290291292293294295296297298299300301302303304305306307308309310311312313314315316317318319320321322323324325326327328329330331332333334335336337338339340341342343344345346347348349350351352353354355356357358359360361362363364365366367368369370371372373374375376377378379380381382383384385386387388389390391392393394395396397398399400401402403404405406407408409410411412413414415416417418419420421422423424425426427428429430431432433434435436437438439440441442443444445446447448449450451452453454455456457458459460461462463464465466467468469470471472473474475476477478479480481482483484485486487488489490491492493494495496497498499500501502503504505506507508509510511512513514515516517518519520521522523524525526527528529530531532533534535536537538539540541542543544545546547548549550551552553554555556557558559560561562563564565566567568569570571572573574575576577578579580581582583584585586587588589590591592593594595596597598599600601602603604605606607608609610611612613614615616617618619620621622623624625626627628629630631632633634635636637638639640641642643644645646647648649650651652653654655656657658659660661662663664665666667668669670671672673674675676677678679680681682683684685686687688689690691692693694695696697698699700701702703704705706707708709710711712713714715716717718719720721722723724725726727728729730731732733734735736737738739740741742743744745746747748749750751752753754755756757758759760761762763764765766767768769770771772773774775776777778779780781782783784785786787788789790791792793794795796797798799800801802803804805806807808809810811812813814815816817818819820821822823824825826827828829830831832833834835836837838839840841842843844845846847848849850851852853854855856857858859860861862863864865866867
  1. <!DOCTYPE html>
  2. <html lang="en">
  3. <head>
  4. <meta charset="UTF-8">
  5. <!--[if IE]><meta http-equiv="X-UA-Compatible" content="IE=edge"><![endif]-->
  6. <meta name="viewport" content="width=device-width, initial-scale=1.0">
  7. <meta name="generator" content="Asciidoctor 1.5.4">
  8. <title>3-D Rotation</title>
  9. <link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Open+Sans:300,300italic,400,400italic,600,600italic%7CNoto+Serif:400,400italic,700,700italic%7CDroid+Sans+Mono:400,700">
  10. <style>
  11. /* Asciidoctor default stylesheet | MIT License | http://asciidoctor.org */
  12. /* Remove comment around @import statement below when using as a custom stylesheet */
  13. /*@import "https://fonts.googleapis.com/css?family=Open+Sans:300,300italic,400,400italic,600,600italic%7CNoto+Serif:400,400italic,700,700italic%7CDroid+Sans+Mono:400,700";*/
  14. article,aside,details,figcaption,figure,footer,header,hgroup,main,nav,section,summary{display:block}
  15. audio,canvas,video{display:inline-block}
  16. audio:not([controls]){display:none;height:0}
  17. [hidden],template{display:none}
  18. script{display:none!important}
  19. html{font-family:sans-serif;-ms-text-size-adjust:100%;-webkit-text-size-adjust:100%}
  20. body{margin:0}
  21. a{background:transparent}
  22. a:focus{outline:thin dotted}
  23. a:active,a:hover{outline:0}
  24. h1{font-size:2em;margin:.67em 0}
  25. abbr[title]{border-bottom:1px dotted}
  26. b,strong{font-weight:bold}
  27. dfn{font-style:italic}
  28. hr{-moz-box-sizing:content-box;box-sizing:content-box;height:0}
  29. mark{background:#ff0;color:#000}
  30. code,kbd,pre,samp{font-family:monospace;font-size:1em}
  31. pre{white-space:pre-wrap}
  32. q{quotes:"\201C" "\201D" "\2018" "\2019"}
  33. small{font-size:80%}
  34. sub,sup{font-size:75%;line-height:0;position:relative;vertical-align:baseline}
  35. sup{top:-.5em}
  36. sub{bottom:-.25em}
  37. img{border:0}
  38. svg:not(:root){overflow:hidden}
  39. figure{margin:0}
  40. fieldset{border:1px solid silver;margin:0 2px;padding:.35em .625em .75em}
  41. legend{border:0;padding:0}
  42. button,input,select,textarea{font-family:inherit;font-size:100%;margin:0}
  43. button,input{line-height:normal}
  44. button,select{text-transform:none}
  45. button,html input[type="button"],input[type="reset"],input[type="submit"]{-webkit-appearance:button;cursor:pointer}
  46. button[disabled],html input[disabled]{cursor:default}
  47. input[type="checkbox"],input[type="radio"]{box-sizing:border-box;padding:0}
  48. input[type="search"]{-webkit-appearance:textfield;-moz-box-sizing:content-box;-webkit-box-sizing:content-box;box-sizing:content-box}
  49. input[type="search"]::-webkit-search-cancel-button,input[type="search"]::-webkit-search-decoration{-webkit-appearance:none}
  50. button::-moz-focus-inner,input::-moz-focus-inner{border:0;padding:0}
  51. textarea{overflow:auto;vertical-align:top}
  52. table{border-collapse:collapse;border-spacing:0}
  53. *,*:before,*:after{-moz-box-sizing:border-box;-webkit-box-sizing:border-box;box-sizing:border-box}
  54. html,body{font-size:100%}
  55. body{background:#fff;color:rgba(0,0,0,.8);padding:0;margin:0;font-family:"Noto Serif","DejaVu Serif",serif;font-weight:400;font-style:normal;line-height:1;position:relative;cursor:auto}
  56. a:hover{cursor:pointer}
  57. img,object,embed{max-width:100%;height:auto}
  58. object,embed{height:100%}
  59. img{-ms-interpolation-mode:bicubic}
  60. .left{float:left!important}
  61. .right{float:right!important}
  62. .text-left{text-align:left!important}
  63. .text-right{text-align:right!important}
  64. .text-center{text-align:center!important}
  65. .text-justify{text-align:justify!important}
  66. .hide{display:none}
  67. body{-webkit-font-smoothing:antialiased}
  68. img,object,svg{display:inline-block;vertical-align:middle}
  69. textarea{height:auto;min-height:50px}
  70. select{width:100%}
  71. .center{margin-left:auto;margin-right:auto}
  72. .spread{width:100%}
  73. p.lead,.paragraph.lead>p,#preamble>.sectionbody>.paragraph:first-of-type p{font-size:1.21875em;line-height:1.6}
  74. .subheader,.admonitionblock td.content>.title,.audioblock>.title,.exampleblock>.title,.imageblock>.title,.listingblock>.title,.literalblock>.title,.stemblock>.title,.openblock>.title,.paragraph>.title,.quoteblock>.title,table.tableblock>.title,.verseblock>.title,.videoblock>.title,.dlist>.title,.olist>.title,.ulist>.title,.qlist>.title,.hdlist>.title{line-height:1.45;color:#7a2518;font-weight:400;margin-top:0;margin-bottom:.25em}
  75. div,dl,dt,dd,ul,ol,li,h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6,pre,form,p,blockquote,th,td{margin:0;padding:0;direction:ltr}
  76. a{color:#2156a5;text-decoration:underline;line-height:inherit}
  77. a:hover,a:focus{color:#1d4b8f}
  78. a img{border:none}
  79. p{font-family:inherit;font-weight:400;font-size:1em;line-height:1.6;margin-bottom:1.25em;text-rendering:optimizeLegibility}
  80. p aside{font-size:.875em;line-height:1.35;font-style:italic}
  81. h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{font-family:"Open Sans","DejaVu Sans",sans-serif;font-weight:300;font-style:normal;color:#ba3925;text-rendering:optimizeLegibility;margin-top:1em;margin-bottom:.5em;line-height:1.0125em}
  82. h1 small,h2 small,h3 small,#toctitle small,.sidebarblock>.content>.title small,h4 small,h5 small,h6 small{font-size:60%;color:#e99b8f;line-height:0}
  83. h1{font-size:2.125em}
  84. h2{font-size:1.6875em}
  85. h3,#toctitle,.sidebarblock>.content>.title{font-size:1.375em}
  86. h4,h5{font-size:1.125em}
  87. h6{font-size:1em}
  88. hr{border:solid #ddddd8;border-width:1px 0 0;clear:both;margin:1.25em 0 1.1875em;height:0}
  89. em,i{font-style:italic;line-height:inherit}
  90. strong,b{font-weight:bold;line-height:inherit}
  91. small{font-size:60%;line-height:inherit}
  92. code{font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;font-weight:400;color:rgba(0,0,0,.9)}
  93. ul,ol,dl{font-size:1em;line-height:1.6;margin-bottom:1.25em;list-style-position:outside;font-family:inherit}
  94. ul,ol,ul.no-bullet,ol.no-bullet{margin-left:1.5em}
  95. ul li ul,ul li ol{margin-left:1.25em;margin-bottom:0;font-size:1em}
  96. ul.square li ul,ul.circle li ul,ul.disc li ul{list-style:inherit}
  97. ul.square{list-style-type:square}
  98. ul.circle{list-style-type:circle}
  99. ul.disc{list-style-type:disc}
  100. ul.no-bullet{list-style:none}
  101. ol li ul,ol li ol{margin-left:1.25em;margin-bottom:0}
  102. dl dt{margin-bottom:.3125em;font-weight:bold}
  103. dl dd{margin-bottom:1.25em}
  104. abbr,acronym{text-transform:uppercase;font-size:90%;color:rgba(0,0,0,.8);border-bottom:1px dotted #ddd;cursor:help}
  105. abbr{text-transform:none}
  106. blockquote{margin:0 0 1.25em;padding:.5625em 1.25em 0 1.1875em;border-left:1px solid #ddd}
  107. blockquote cite{display:block;font-size:.9375em;color:rgba(0,0,0,.6)}
  108. blockquote cite:before{content:"\2014 \0020"}
  109. blockquote cite a,blockquote cite a:visited{color:rgba(0,0,0,.6)}
  110. blockquote,blockquote p{line-height:1.6;color:rgba(0,0,0,.85)}
  111. @media only screen and (min-width:768px){h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{line-height:1.2}
  112. h1{font-size:2.75em}
  113. h2{font-size:2.3125em}
  114. h3,#toctitle,.sidebarblock>.content>.title{font-size:1.6875em}
  115. h4{font-size:1.4375em}}
  116. table{background:#fff;margin-bottom:1.25em;border:solid 1px #dedede}
  117. table thead,table tfoot{background:#f7f8f7;font-weight:bold}
  118. table thead tr th,table thead tr td,table tfoot tr th,table tfoot tr td{padding:.5em .625em .625em;font-size:inherit;color:rgba(0,0,0,.8);text-align:left}
  119. table tr th,table tr td{padding:.5625em .625em;font-size:inherit;color:rgba(0,0,0,.8)}
  120. table tr.even,table tr.alt,table tr:nth-of-type(even){background:#f8f8f7}
  121. table thead tr th,table tfoot tr th,table tbody tr td,table tr td,table tfoot tr td{display:table-cell;line-height:1.6}
  122. body{tab-size:4}
  123. h1,h2,h3,#toctitle,.sidebarblock>.content>.title,h4,h5,h6{line-height:1.2;word-spacing:-.05em}
  124. h1 strong,h2 strong,h3 strong,#toctitle strong,.sidebarblock>.content>.title strong,h4 strong,h5 strong,h6 strong{font-weight:400}
  125. .clearfix:before,.clearfix:after,.float-group:before,.float-group:after{content:" ";display:table}
  126. .clearfix:after,.float-group:after{clear:both}
  127. *:not(pre)>code{font-size:.9375em;font-style:normal!important;letter-spacing:0;padding:.1em .5ex;word-spacing:-.15em;background-color:#f7f7f8;-webkit-border-radius:4px;border-radius:4px;line-height:1.45;text-rendering:optimizeSpeed}
  128. pre,pre>code{line-height:1.45;color:rgba(0,0,0,.9);font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;font-weight:400;text-rendering:optimizeSpeed}
  129. .keyseq{color:rgba(51,51,51,.8)}
  130. kbd{font-family:"Droid Sans Mono","DejaVu Sans Mono",monospace;display:inline-block;color:rgba(0,0,0,.8);font-size:.65em;line-height:1.45;background-color:#f7f7f7;border:1px solid #ccc;-webkit-border-radius:3px;border-radius:3px;-webkit-box-shadow:0 1px 0 rgba(0,0,0,.2),0 0 0 .1em white inset;box-shadow:0 1px 0 rgba(0,0,0,.2),0 0 0 .1em #fff inset;margin:0 .15em;padding:.2em .5em;vertical-align:middle;position:relative;top:-.1em;white-space:nowrap}
  131. .keyseq kbd:first-child{margin-left:0}
  132. .keyseq kbd:last-child{margin-right:0}
  133. .menuseq,.menu{color:rgba(0,0,0,.8)}
  134. b.button:before,b.button:after{position:relative;top:-1px;font-weight:400}
  135. b.button:before{content:"[";padding:0 3px 0 2px}
  136. b.button:after{content:"]";padding:0 2px 0 3px}
  137. p a>code:hover{color:rgba(0,0,0,.9)}
  138. #header,#content,#footnotes,#footer{width:100%;margin-left:auto;margin-right:auto;margin-top:0;margin-bottom:0;max-width:62.5em;*zoom:1;position:relative;padding-left:.9375em;padding-right:.9375em}
  139. #header:before,#header:after,#content:before,#content:after,#footnotes:before,#footnotes:after,#footer:before,#footer:after{content:" ";display:table}
  140. #header:after,#content:after,#footnotes:after,#footer:after{clear:both}
  141. #content{margin-top:1.25em}
  142. #content:before{content:none}
  143. #header>h1:first-child{color:rgba(0,0,0,.85);margin-top:2.25rem;margin-bottom:0}
  144. #header>h1:first-child+#toc{margin-top:8px;border-top:1px solid #ddddd8}
  145. #header>h1:only-child,body.toc2 #header>h1:nth-last-child(2){border-bottom:1px solid #ddddd8;padding-bottom:8px}
  146. #header .details{border-bottom:1px solid #ddddd8;line-height:1.45;padding-top:.25em;padding-bottom:.25em;padding-left:.25em;color:rgba(0,0,0,.6);display:-ms-flexbox;display:-webkit-flex;display:flex;-ms-flex-flow:row wrap;-webkit-flex-flow:row wrap;flex-flow:row wrap}
  147. #header .details span:first-child{margin-left:-.125em}
  148. #header .details span.email a{color:rgba(0,0,0,.85)}
  149. #header .details br{display:none}
  150. #header .details br+span:before{content:"\00a0\2013\00a0"}
  151. #header .details br+span.author:before{content:"\00a0\22c5\00a0";color:rgba(0,0,0,.85)}
  152. #header .details br+span#revremark:before{content:"\00a0|\00a0"}
  153. #header #revnumber{text-transform:capitalize}
  154. #header #revnumber:after{content:"\00a0"}
  155. #content>h1:first-child:not([class]){color:rgba(0,0,0,.85);border-bottom:1px solid #ddddd8;padding-bottom:8px;margin-top:0;padding-top:1rem;margin-bottom:1.25rem}
  156. #toc{border-bottom:1px solid #efefed;padding-bottom:.5em}
  157. #toc>ul{margin-left:.125em}
  158. #toc ul.sectlevel0>li>a{font-style:italic}
  159. #toc ul.sectlevel0 ul.sectlevel1{margin:.5em 0}
  160. #toc ul{font-family:"Open Sans","DejaVu Sans",sans-serif;list-style-type:none}
  161. #toc li{line-height:1.3334;margin-top:.3334em}
  162. #toc a{text-decoration:none}
  163. #toc a:active{text-decoration:underline}
  164. #toctitle{color:#7a2518;font-size:1.2em}
  165. @media only screen and (min-width:768px){#toctitle{font-size:1.375em}
  166. body.toc2{padding-left:15em;padding-right:0}
  167. #toc.toc2{margin-top:0!important;background-color:#f8f8f7;position:fixed;width:15em;left:0;top:0;border-right:1px solid #efefed;border-top-width:0!important;border-bottom-width:0!important;z-index:1000;padding:1.25em 1em;height:100%;overflow:auto}
  168. #toc.toc2 #toctitle{margin-top:0;margin-bottom:.8rem;font-size:1.2em}
  169. #toc.toc2>ul{font-size:.9em;margin-bottom:0}
  170. #toc.toc2 ul ul{margin-left:0;padding-left:1em}
  171. #toc.toc2 ul.sectlevel0 ul.sectlevel1{padding-left:0;margin-top:.5em;margin-bottom:.5em}
  172. body.toc2.toc-right{padding-left:0;padding-right:15em}
  173. body.toc2.toc-right #toc.toc2{border-right-width:0;border-left:1px solid #efefed;left:auto;right:0}}
  174. @media only screen and (min-width:1280px){body.toc2{padding-left:20em;padding-right:0}
  175. #toc.toc2{width:20em}
  176. #toc.toc2 #toctitle{font-size:1.375em}
  177. #toc.toc2>ul{font-size:.95em}
  178. #toc.toc2 ul ul{padding-left:1.25em}
  179. body.toc2.toc-right{padding-left:0;padding-right:20em}}
  180. #content #toc{border-style:solid;border-width:1px;border-color:#e0e0dc;margin-bottom:1.25em;padding:1.25em;background:#f8f8f7;-webkit-border-radius:4px;border-radius:4px}
  181. #content #toc>:first-child{margin-top:0}
  182. #content #toc>:last-child{margin-bottom:0}
  183. #footer{max-width:100%;background-color:rgba(0,0,0,.8);padding:1.25em}
  184. #footer-text{color:rgba(255,255,255,.8);line-height:1.44}
  185. .sect1{padding-bottom:.625em}
  186. @media only screen and (min-width:768px){.sect1{padding-bottom:1.25em}}
  187. .sect1+.sect1{border-top:1px solid #efefed}
  188. #content h1>a.anchor,h2>a.anchor,h3>a.anchor,#toctitle>a.anchor,.sidebarblock>.content>.title>a.anchor,h4>a.anchor,h5>a.anchor,h6>a.anchor{position:absolute;z-index:1001;width:1.5ex;margin-left:-1.5ex;display:block;text-decoration:none!important;visibility:hidden;text-align:center;font-weight:400}
  189. #content h1>a.anchor:before,h2>a.anchor:before,h3>a.anchor:before,#toctitle>a.anchor:before,.sidebarblock>.content>.title>a.anchor:before,h4>a.anchor:before,h5>a.anchor:before,h6>a.anchor:before{content:"\00A7";font-size:.85em;display:block;padding-top:.1em}
  190. #content h1:hover>a.anchor,#content h1>a.anchor:hover,h2:hover>a.anchor,h2>a.anchor:hover,h3:hover>a.anchor,#toctitle:hover>a.anchor,.sidebarblock>.content>.title:hover>a.anchor,h3>a.anchor:hover,#toctitle>a.anchor:hover,.sidebarblock>.content>.title>a.anchor:hover,h4:hover>a.anchor,h4>a.anchor:hover,h5:hover>a.anchor,h5>a.anchor:hover,h6:hover>a.anchor,h6>a.anchor:hover{visibility:visible}
  191. #content h1>a.link,h2>a.link,h3>a.link,#toctitle>a.link,.sidebarblock>.content>.title>a.link,h4>a.link,h5>a.link,h6>a.link{color:#ba3925;text-decoration:none}
  192. #content h1>a.link:hover,h2>a.link:hover,h3>a.link:hover,#toctitle>a.link:hover,.sidebarblock>.content>.title>a.link:hover,h4>a.link:hover,h5>a.link:hover,h6>a.link:hover{color:#a53221}
  193. .audioblock,.imageblock,.literalblock,.listingblock,.stemblock,.videoblock{margin-bottom:1.25em}
  194. .admonitionblock td.content>.title,.audioblock>.title,.exampleblock>.title,.imageblock>.title,.listingblock>.title,.literalblock>.title,.stemblock>.title,.openblock>.title,.paragraph>.title,.quoteblock>.title,table.tableblock>.title,.verseblock>.title,.videoblock>.title,.dlist>.title,.olist>.title,.ulist>.title,.qlist>.title,.hdlist>.title{text-rendering:optimizeLegibility;text-align:left;font-family:"Noto Serif","DejaVu Serif",serif;font-size:1rem;font-style:italic}
  195. table.tableblock>caption.title{white-space:nowrap;overflow:visible;max-width:0}
  196. .paragraph.lead>p,#preamble>.sectionbody>.paragraph:first-of-type p{color:rgba(0,0,0,.85)}
  197. table.tableblock #preamble>.sectionbody>.paragraph:first-of-type p{font-size:inherit}
  198. .admonitionblock>table{border-collapse:separate;border:0;background:none;width:100%}
  199. .admonitionblock>table td.icon{text-align:center;width:80px}
  200. .admonitionblock>table td.icon img{max-width:none}
  201. .admonitionblock>table td.icon .title{font-weight:bold;font-family:"Open Sans","DejaVu Sans",sans-serif;text-transform:uppercase}
  202. .admonitionblock>table td.content{padding-left:1.125em;padding-right:1.25em;border-left:1px solid #ddddd8;color:rgba(0,0,0,.6)}
  203. .admonitionblock>table td.content>:last-child>:last-child{margin-bottom:0}
  204. .exampleblock>.content{border-style:solid;border-width:1px;border-color:#e6e6e6;margin-bottom:1.25em;padding:1.25em;background:#fff;-webkit-border-radius:4px;border-radius:4px}
  205. .exampleblock>.content>:first-child{margin-top:0}
  206. .exampleblock>.content>:last-child{margin-bottom:0}
  207. .sidebarblock{border-style:solid;border-width:1px;border-color:#e0e0dc;margin-bottom:1.25em;padding:1.25em;background:#f8f8f7;-webkit-border-radius:4px;border-radius:4px}
  208. .sidebarblock>:first-child{margin-top:0}
  209. .sidebarblock>:last-child{margin-bottom:0}
  210. .sidebarblock>.content>.title{color:#7a2518;margin-top:0;text-align:center}
  211. .exampleblock>.content>:last-child>:last-child,.exampleblock>.content .olist>ol>li:last-child>:last-child,.exampleblock>.content .ulist>ul>li:last-child>:last-child,.exampleblock>.content .qlist>ol>li:last-child>:last-child,.sidebarblock>.content>:last-child>:last-child,.sidebarblock>.content .olist>ol>li:last-child>:last-child,.sidebarblock>.content .ulist>ul>li:last-child>:last-child,.sidebarblock>.content .qlist>ol>li:last-child>:last-child{margin-bottom:0}
  212. .literalblock pre,.listingblock pre:not(.highlight),.listingblock pre[class="highlight"],.listingblock pre[class^="highlight "],.listingblock pre.CodeRay,.listingblock pre.prettyprint{background:#f7f7f8}
  213. .sidebarblock .literalblock pre,.sidebarblock .listingblock pre:not(.highlight),.sidebarblock .listingblock pre[class="highlight"],.sidebarblock .listingblock pre[class^="highlight "],.sidebarblock .listingblock pre.CodeRay,.sidebarblock .listingblock pre.prettyprint{background:#f2f1f1}
  214. .literalblock pre,.literalblock pre[class],.listingblock pre,.listingblock pre[class]{-webkit-border-radius:4px;border-radius:4px;word-wrap:break-word;padding:1em;font-size:.8125em}
  215. .literalblock pre.nowrap,.literalblock pre[class].nowrap,.listingblock pre.nowrap,.listingblock pre[class].nowrap{overflow-x:auto;white-space:pre;word-wrap:normal}
  216. @media only screen and (min-width:768px){.literalblock pre,.literalblock pre[class],.listingblock pre,.listingblock pre[class]{font-size:.90625em}}
  217. @media only screen and (min-width:1280px){.literalblock pre,.literalblock pre[class],.listingblock pre,.listingblock pre[class]{font-size:1em}}
  218. .literalblock.output pre{color:#f7f7f8;background-color:rgba(0,0,0,.9)}
  219. .listingblock pre.highlightjs{padding:0}
  220. .listingblock pre.highlightjs>code{padding:1em;-webkit-border-radius:4px;border-radius:4px}
  221. .listingblock pre.prettyprint{border-width:0}
  222. .listingblock>.content{position:relative}
  223. .listingblock code[data-lang]:before{display:none;content:attr(data-lang);position:absolute;font-size:.75em;top:.425rem;right:.5rem;line-height:1;text-transform:uppercase;color:#999}
  224. .listingblock:hover code[data-lang]:before{display:block}
  225. .listingblock.terminal pre .command:before{content:attr(data-prompt);padding-right:.5em;color:#999}
  226. .listingblock.terminal pre .command:not([data-prompt]):before{content:"$"}
  227. table.pyhltable{border-collapse:separate;border:0;margin-bottom:0;background:none}
  228. table.pyhltable td{vertical-align:top;padding-top:0;padding-bottom:0;line-height:1.45}
  229. table.pyhltable td.code{padding-left:.75em;padding-right:0}
  230. pre.pygments .lineno,table.pyhltable td:not(.code){color:#999;padding-left:0;padding-right:.5em;border-right:1px solid #ddddd8}
  231. pre.pygments .lineno{display:inline-block;margin-right:.25em}
  232. table.pyhltable .linenodiv{background:none!important;padding-right:0!important}
  233. .quoteblock{margin:0 1em 1.25em 1.5em;display:table}
  234. .quoteblock>.title{margin-left:-1.5em;margin-bottom:.75em}
  235. .quoteblock blockquote,.quoteblock blockquote p{color:rgba(0,0,0,.85);font-size:1.15rem;line-height:1.75;word-spacing:.1em;letter-spacing:0;font-style:italic;text-align:justify}
  236. .quoteblock blockquote{margin:0;padding:0;border:0}
  237. .quoteblock blockquote:before{content:"\201c";float:left;font-size:2.75em;font-weight:bold;line-height:.6em;margin-left:-.6em;color:#7a2518;text-shadow:0 1px 2px rgba(0,0,0,.1)}
  238. .quoteblock blockquote>.paragraph:last-child p{margin-bottom:0}
  239. .quoteblock .attribution{margin-top:.5em;margin-right:.5ex;text-align:right}
  240. .quoteblock .quoteblock{margin-left:0;margin-right:0;padding:.5em 0;border-left:3px solid rgba(0,0,0,.6)}
  241. .quoteblock .quoteblock blockquote{padding:0 0 0 .75em}
  242. .quoteblock .quoteblock blockquote:before{display:none}
  243. .verseblock{margin:0 1em 1.25em 1em}
  244. .verseblock pre{font-family:"Open Sans","DejaVu Sans",sans;font-size:1.15rem;color:rgba(0,0,0,.85);font-weight:300;text-rendering:optimizeLegibility}
  245. .verseblock pre strong{font-weight:400}
  246. .verseblock .attribution{margin-top:1.25rem;margin-left:.5ex}
  247. .quoteblock .attribution,.verseblock .attribution{font-size:.9375em;line-height:1.45;font-style:italic}
  248. .quoteblock .attribution br,.verseblock .attribution br{display:none}
  249. .quoteblock .attribution cite,.verseblock .attribution cite{display:block;letter-spacing:-.025em;color:rgba(0,0,0,.6)}
  250. .quoteblock.abstract{margin:0 0 1.25em 0;display:block}
  251. .quoteblock.abstract blockquote,.quoteblock.abstract blockquote p{text-align:left;word-spacing:0}
  252. .quoteblock.abstract blockquote:before,.quoteblock.abstract blockquote p:first-of-type:before{display:none}
  253. table.tableblock{max-width:100%;border-collapse:separate}
  254. table.tableblock td>.paragraph:last-child p>p:last-child,table.tableblock th>p:last-child,table.tableblock td>p:last-child{margin-bottom:0}
  255. table.tableblock,th.tableblock,td.tableblock{border:0 solid #dedede}
  256. table.grid-all th.tableblock,table.grid-all td.tableblock{border-width:0 1px 1px 0}
  257. table.grid-all tfoot>tr>th.tableblock,table.grid-all tfoot>tr>td.tableblock{border-width:1px 1px 0 0}
  258. table.grid-cols th.tableblock,table.grid-cols td.tableblock{border-width:0 1px 0 0}
  259. table.grid-all *>tr>.tableblock:last-child,table.grid-cols *>tr>.tableblock:last-child{border-right-width:0}
  260. table.grid-rows th.tableblock,table.grid-rows td.tableblock{border-width:0 0 1px 0}
  261. table.grid-all tbody>tr:last-child>th.tableblock,table.grid-all tbody>tr:last-child>td.tableblock,table.grid-all thead:last-child>tr>th.tableblock,table.grid-rows tbody>tr:last-child>th.tableblock,table.grid-rows tbody>tr:last-child>td.tableblock,table.grid-rows thead:last-child>tr>th.tableblock{border-bottom-width:0}
  262. table.grid-rows tfoot>tr>th.tableblock,table.grid-rows tfoot>tr>td.tableblock{border-width:1px 0 0 0}
  263. table.frame-all{border-width:1px}
  264. table.frame-sides{border-width:0 1px}
  265. table.frame-topbot{border-width:1px 0}
  266. th.halign-left,td.halign-left{text-align:left}
  267. th.halign-right,td.halign-right{text-align:right}
  268. th.halign-center,td.halign-center{text-align:center}
  269. th.valign-top,td.valign-top{vertical-align:top}
  270. th.valign-bottom,td.valign-bottom{vertical-align:bottom}
  271. th.valign-middle,td.valign-middle{vertical-align:middle}
  272. table thead th,table tfoot th{font-weight:bold}
  273. tbody tr th{display:table-cell;line-height:1.6;background:#f7f8f7}
  274. tbody tr th,tbody tr th p,tfoot tr th,tfoot tr th p{color:rgba(0,0,0,.8);font-weight:bold}
  275. p.tableblock>code:only-child{background:none;padding:0}
  276. p.tableblock{font-size:1em}
  277. td>div.verse{white-space:pre}
  278. ol{margin-left:1.75em}
  279. ul li ol{margin-left:1.5em}
  280. dl dd{margin-left:1.125em}
  281. dl dd:last-child,dl dd:last-child>:last-child{margin-bottom:0}
  282. ol>li p,ul>li p,ul dd,ol dd,.olist .olist,.ulist .ulist,.ulist .olist,.olist .ulist{margin-bottom:.625em}
  283. ul.unstyled,ol.unnumbered,ul.checklist,ul.none{list-style-type:none}
  284. ul.unstyled,ol.unnumbered,ul.checklist{margin-left:.625em}
  285. ul.checklist li>p:first-child>.fa-square-o:first-child,ul.checklist li>p:first-child>.fa-check-square-o:first-child{width:1em;font-size:.85em}
  286. ul.checklist li>p:first-child>input[type="checkbox"]:first-child{width:1em;position:relative;top:1px}
  287. ul.inline{margin:0 auto .625em auto;margin-left:-1.375em;margin-right:0;padding:0;list-style:none;overflow:hidden}
  288. ul.inline>li{list-style:none;float:left;margin-left:1.375em;display:block}
  289. ul.inline>li>*{display:block}
  290. .unstyled dl dt{font-weight:400;font-style:normal}
  291. ol.arabic{list-style-type:decimal}
  292. ol.decimal{list-style-type:decimal-leading-zero}
  293. ol.loweralpha{list-style-type:lower-alpha}
  294. ol.upperalpha{list-style-type:upper-alpha}
  295. ol.lowerroman{list-style-type:lower-roman}
  296. ol.upperroman{list-style-type:upper-roman}
  297. ol.lowergreek{list-style-type:lower-greek}
  298. .hdlist>table,.colist>table{border:0;background:none}
  299. .hdlist>table>tbody>tr,.colist>table>tbody>tr{background:none}
  300. td.hdlist1,td.hdlist2{vertical-align:top;padding:0 .625em}
  301. td.hdlist1{font-weight:bold;padding-bottom:1.25em}
  302. .literalblock+.colist,.listingblock+.colist{margin-top:-.5em}
  303. .colist>table tr>td:first-of-type{padding:0 .75em;line-height:1}
  304. .colist>table tr>td:last-of-type{padding:.25em 0}
  305. .thumb,.th{line-height:0;display:inline-block;border:solid 4px #fff;-webkit-box-shadow:0 0 0 1px #ddd;box-shadow:0 0 0 1px #ddd}
  306. .imageblock.left,.imageblock[style*="float: left"]{margin:.25em .625em 1.25em 0}
  307. .imageblock.right,.imageblock[style*="float: right"]{margin:.25em 0 1.25em .625em}
  308. .imageblock>.title{margin-bottom:0}
  309. .imageblock.thumb,.imageblock.th{border-width:6px}
  310. .imageblock.thumb>.title,.imageblock.th>.title{padding:0 .125em}
  311. .image.left,.image.right{margin-top:.25em;margin-bottom:.25em;display:inline-block;line-height:0}
  312. .image.left{margin-right:.625em}
  313. .image.right{margin-left:.625em}
  314. a.image{text-decoration:none;display:inline-block}
  315. a.image object{pointer-events:none}
  316. sup.footnote,sup.footnoteref{font-size:.875em;position:static;vertical-align:super}
  317. sup.footnote a,sup.footnoteref a{text-decoration:none}
  318. sup.footnote a:active,sup.footnoteref a:active{text-decoration:underline}
  319. #footnotes{padding-top:.75em;padding-bottom:.75em;margin-bottom:.625em}
  320. #footnotes hr{width:20%;min-width:6.25em;margin:-.25em 0 .75em 0;border-width:1px 0 0 0}
  321. #footnotes .footnote{padding:0 .375em 0 .225em;line-height:1.3334;font-size:.875em;margin-left:1.2em;text-indent:-1.05em;margin-bottom:.2em}
  322. #footnotes .footnote a:first-of-type{font-weight:bold;text-decoration:none}
  323. #footnotes .footnote:last-of-type{margin-bottom:0}
  324. #content #footnotes{margin-top:-.625em;margin-bottom:0;padding:.75em 0}
  325. .gist .file-data>table{border:0;background:#fff;width:100%;margin-bottom:0}
  326. .gist .file-data>table td.line-data{width:99%}
  327. div.unbreakable{page-break-inside:avoid}
  328. .big{font-size:larger}
  329. .small{font-size:smaller}
  330. .underline{text-decoration:underline}
  331. .overline{text-decoration:overline}
  332. .line-through{text-decoration:line-through}
  333. .aqua{color:#00bfbf}
  334. .aqua-background{background-color:#00fafa}
  335. .black{color:#000}
  336. .black-background{background-color:#000}
  337. .blue{color:#0000bf}
  338. .blue-background{background-color:#0000fa}
  339. .fuchsia{color:#bf00bf}
  340. .fuchsia-background{background-color:#fa00fa}
  341. .gray{color:#606060}
  342. .gray-background{background-color:#7d7d7d}
  343. .green{color:#006000}
  344. .green-background{background-color:#007d00}
  345. .lime{color:#00bf00}
  346. .lime-background{background-color:#00fa00}
  347. .maroon{color:#600000}
  348. .maroon-background{background-color:#7d0000}
  349. .navy{color:#000060}
  350. .navy-background{background-color:#00007d}
  351. .olive{color:#606000}
  352. .olive-background{background-color:#7d7d00}
  353. .purple{color:#600060}
  354. .purple-background{background-color:#7d007d}
  355. .red{color:#bf0000}
  356. .red-background{background-color:#fa0000}
  357. .silver{color:#909090}
  358. .silver-background{background-color:#bcbcbc}
  359. .teal{color:#006060}
  360. .teal-background{background-color:#007d7d}
  361. .white{color:#bfbfbf}
  362. .white-background{background-color:#fafafa}
  363. .yellow{color:#bfbf00}
  364. .yellow-background{background-color:#fafa00}
  365. span.icon>.fa{cursor:default}
  366. .admonitionblock td.icon [class^="fa icon-"]{font-size:2.5em;text-shadow:1px 1px 2px rgba(0,0,0,.5);cursor:default}
  367. .admonitionblock td.icon .icon-note:before{content:"\f05a";color:#19407c}
  368. .admonitionblock td.icon .icon-tip:before{content:"\f0eb";text-shadow:1px 1px 2px rgba(155,155,0,.8);color:#111}
  369. .admonitionblock td.icon .icon-warning:before{content:"\f071";color:#bf6900}
  370. .admonitionblock td.icon .icon-caution:before{content:"\f06d";color:#bf3400}
  371. .admonitionblock td.icon .icon-important:before{content:"\f06a";color:#bf0000}
  372. .conum[data-value]{display:inline-block;color:#fff!important;background-color:rgba(0,0,0,.8);-webkit-border-radius:100px;border-radius:100px;text-align:center;font-size:.75em;width:1.67em;height:1.67em;line-height:1.67em;font-family:"Open Sans","DejaVu Sans",sans-serif;font-style:normal;font-weight:bold}
  373. .conum[data-value] *{color:#fff!important}
  374. .conum[data-value]+b{display:none}
  375. .conum[data-value]:after{content:attr(data-value)}
  376. pre .conum[data-value]{position:relative;top:-.125em}
  377. b.conum *{color:inherit!important}
  378. .conum:not([data-value]):empty{display:none}
  379. dt,th.tableblock,td.content,div.footnote{text-rendering:optimizeLegibility}
  380. h1,h2,p,td.content,span.alt{letter-spacing:-.01em}
  381. p strong,td.content strong,div.footnote strong{letter-spacing:-.005em}
  382. p,blockquote,dt,td.content,span.alt{font-size:1.0625rem}
  383. p{margin-bottom:1.25rem}
  384. .sidebarblock p,.sidebarblock dt,.sidebarblock td.content,p.tableblock{font-size:1em}
  385. .exampleblock>.content{background-color:#fffef7;border-color:#e0e0dc;-webkit-box-shadow:0 1px 4px #e0e0dc;box-shadow:0 1px 4px #e0e0dc}
  386. .print-only{display:none!important}
  387. @media print{@page{margin:1.25cm .75cm}
  388. *{-webkit-box-shadow:none!important;box-shadow:none!important;text-shadow:none!important}
  389. a{color:inherit!important;text-decoration:underline!important}
  390. a.bare,a[href^="#"],a[href^="mailto:"]{text-decoration:none!important}
  391. a[href^="http:"]:not(.bare):after,a[href^="https:"]:not(.bare):after{content:"(" attr(href) ")";display:inline-block;font-size:.875em;padding-left:.25em}
  392. abbr[title]:after{content:" (" attr(title) ")"}
  393. pre,blockquote,tr,img,object,svg{page-break-inside:avoid}
  394. thead{display:table-header-group}
  395. svg{max-width:100%}
  396. p,blockquote,dt,td.content{font-size:1em;orphans:3;widows:3}
  397. h2,h3,#toctitle,.sidebarblock>.content>.title{page-break-after:avoid}
  398. #toc,.sidebarblock,.exampleblock>.content{background:none!important}
  399. #toc{border-bottom:1px solid #ddddd8!important;padding-bottom:0!important}
  400. .sect1{padding-bottom:0!important}
  401. .sect1+.sect1{border:0!important}
  402. #header>h1:first-child{margin-top:1.25rem}
  403. body.book #header{text-align:center}
  404. body.book #header>h1:first-child{border:0!important;margin:2.5em 0 1em 0}
  405. body.book #header .details{border:0!important;display:block;padding:0!important}
  406. body.book #header .details span:first-child{margin-left:0!important}
  407. body.book #header .details br{display:block}
  408. body.book #header .details br+span:before{content:none!important}
  409. body.book #toc{border:0!important;text-align:left!important;padding:0!important;margin:0!important}
  410. body.book #toc,body.book #preamble,body.book h1.sect0,body.book .sect1>h2{page-break-before:always}
  411. .listingblock code[data-lang]:before{display:block}
  412. #footer{background:none!important;padding:0 .9375em}
  413. #footer-text{color:rgba(0,0,0,.6)!important;font-size:.9em}
  414. .hide-on-print{display:none!important}
  415. .print-only{display:block!important}
  416. .hide-for-print{display:none!important}
  417. .show-for-print{display:inherit!important}}
  418. </style>
  419. <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.5.0/css/font-awesome.min.css">
  420. <style>
  421. /* Stylesheet for CodeRay to match GitHub theme | MIT License | http://foundation.zurb.com */
  422. /*pre.CodeRay {background-color:#f7f7f8;}*/
  423. .CodeRay .line-numbers{border-right:1px solid #d8d8d8;padding:0 0.5em 0 .25em}
  424. .CodeRay span.line-numbers{display:inline-block;margin-right:.5em;color:rgba(0,0,0,.3)}
  425. .CodeRay .line-numbers strong{color:rgba(0,0,0,.4)}
  426. table.CodeRay{border-collapse:separate;border-spacing:0;margin-bottom:0;border:0;background:none}
  427. table.CodeRay td{vertical-align: top;line-height:1.45}
  428. table.CodeRay td.line-numbers{text-align:right}
  429. table.CodeRay td.line-numbers>pre{padding:0;color:rgba(0,0,0,.3)}
  430. table.CodeRay td.code{padding:0 0 0 .5em}
  431. table.CodeRay td.code>pre{padding:0}
  432. .CodeRay .debug{color:#fff !important;background:#000080 !important}
  433. .CodeRay .annotation{color:#007}
  434. .CodeRay .attribute-name{color:#000080}
  435. .CodeRay .attribute-value{color:#700}
  436. .CodeRay .binary{color:#509}
  437. .CodeRay .comment{color:#998;font-style:italic}
  438. .CodeRay .char{color:#04d}
  439. .CodeRay .char .content{color:#04d}
  440. .CodeRay .char .delimiter{color:#039}
  441. .CodeRay .class{color:#458;font-weight:bold}
  442. .CodeRay .complex{color:#a08}
  443. .CodeRay .constant,.CodeRay .predefined-constant{color:#008080}
  444. .CodeRay .color{color:#099}
  445. .CodeRay .class-variable{color:#369}
  446. .CodeRay .decorator{color:#b0b}
  447. .CodeRay .definition{color:#099}
  448. .CodeRay .delimiter{color:#000}
  449. .CodeRay .doc{color:#970}
  450. .CodeRay .doctype{color:#34b}
  451. .CodeRay .doc-string{color:#d42}
  452. .CodeRay .escape{color:#666}
  453. .CodeRay .entity{color:#800}
  454. .CodeRay .error{color:#808}
  455. .CodeRay .exception{color:inherit}
  456. .CodeRay .filename{color:#099}
  457. .CodeRay .function{color:#900;font-weight:bold}
  458. .CodeRay .global-variable{color:#008080}
  459. .CodeRay .hex{color:#058}
  460. .CodeRay .integer,.CodeRay .float{color:#099}
  461. .CodeRay .include{color:#555}
  462. .CodeRay .inline{color:#000}
  463. .CodeRay .inline .inline{background:#ccc}
  464. .CodeRay .inline .inline .inline{background:#bbb}
  465. .CodeRay .inline .inline-delimiter{color:#d14}
  466. .CodeRay .inline-delimiter{color:#d14}
  467. .CodeRay .important{color:#555;font-weight:bold}
  468. .CodeRay .interpreted{color:#b2b}
  469. .CodeRay .instance-variable{color:#008080}
  470. .CodeRay .label{color:#970}
  471. .CodeRay .local-variable{color:#963}
  472. .CodeRay .octal{color:#40e}
  473. .CodeRay .predefined{color:#369}
  474. .CodeRay .preprocessor{color:#579}
  475. .CodeRay .pseudo-class{color:#555}
  476. .CodeRay .directive{font-weight:bold}
  477. .CodeRay .type{font-weight:bold}
  478. .CodeRay .predefined-type{color:inherit}
  479. .CodeRay .reserved,.CodeRay .keyword {color:#000;font-weight:bold}
  480. .CodeRay .key{color:#808}
  481. .CodeRay .key .delimiter{color:#606}
  482. .CodeRay .key .char{color:#80f}
  483. .CodeRay .value{color:#088}
  484. .CodeRay .regexp .delimiter{color:#808}
  485. .CodeRay .regexp .content{color:#808}
  486. .CodeRay .regexp .modifier{color:#808}
  487. .CodeRay .regexp .char{color:#d14}
  488. .CodeRay .regexp .function{color:#404;font-weight:bold}
  489. .CodeRay .string{color:#d20}
  490. .CodeRay .string .string .string{background:#ffd0d0}
  491. .CodeRay .string .content{color:#d14}
  492. .CodeRay .string .char{color:#d14}
  493. .CodeRay .string .delimiter{color:#d14}
  494. .CodeRay .shell{color:#d14}
  495. .CodeRay .shell .delimiter{color:#d14}
  496. .CodeRay .symbol{color:#990073}
  497. .CodeRay .symbol .content{color:#a60}
  498. .CodeRay .symbol .delimiter{color:#630}
  499. .CodeRay .tag{color:#008080}
  500. .CodeRay .tag-special{color:#d70}
  501. .CodeRay .variable{color:#036}
  502. .CodeRay .insert{background:#afa}
  503. .CodeRay .delete{background:#faa}
  504. .CodeRay .change{color:#aaf;background:#007}
  505. .CodeRay .head{color:#f8f;background:#505}
  506. .CodeRay .insert .insert{color:#080}
  507. .CodeRay .delete .delete{color:#800}
  508. .CodeRay .change .change{color:#66f}
  509. .CodeRay .head .head{color:#f4f}
  510. </style>
  511. </head>
  512. <body class="article toc2 toc-left">
  513. <div id="header">
  514. <h1>3-D Rotation</h1>
  515. <div id="toc" class="toc2">
  516. <div id="toctitle">Table of Contents</div>
  517. <ul class="sectlevel1">
  518. <li><a href="#using-quaternions-for-rotation">Using Quaternions for Rotation</a></li>
  519. <li><a href="#code-sample">Code Sample</a></li>
  520. <li><a href="#interpolating-rotations">Interpolating Rotations</a></li>
  521. <li><a href="#adding-rotations">"Adding" Rotations</a></li>
  522. <li><a href="#troubleshooting-rotations">Troubleshooting Rotations</a></li>
  523. <li><a href="#tip-transformation-matrix">Tip: Transformation Matrix</a></li>
  524. </ul>
  525. </div>
  526. </div>
  527. <div id="content">
  528. <div id="preamble">
  529. <div class="sectionbody">
  530. <div class="paragraph">
  531. <p><em>Bad news: 3D rotation is done using matrix calculus.<br>
  532. Good news: If you do not understand calculus, there are two simple rules how you get it right.</em></p>
  533. </div>
  534. <div class="paragraph">
  535. <p>+</p>
  536. </div>
  537. <div class="paragraph">
  538. <p><strong>3D rotation</strong> is a crazy mathematical operation where you need to multiply all vertices in your object by four floating point numbers; the multiplication is referred to as concatenation, the array of four numbers {x,y,z,w} is referred to as quaternion. Don&#8217;t worry, the 3D engine does the tough work for you. All you need to know is:</p>
  539. </div>
  540. <div class="paragraph">
  541. <p><strong>The Quaternion</strong> is an object capable of deep-freezing and storing a rotation that you can apply to a 3D object.</p>
  542. </div>
  543. </div>
  544. </div>
  545. <div class="sect1">
  546. <h2 id="using-quaternions-for-rotation">Using Quaternions for Rotation</h2>
  547. <div class="sectionbody">
  548. <div class="paragraph">
  549. <p>To store a rotation in a Quaternion, you must specify two things: The angle and the axis of the rotation.</p>
  550. </div>
  551. <div class="ulist">
  552. <ul>
  553. <li>
  554. <p>The rotation angle is defined as a multiple of the number PI.</p>
  555. </li>
  556. <li>
  557. <p>The rotation axis is defined by a vector: Think of them in terms of “pitch, “yaw, and “roll.</p>
  558. </li>
  559. </ul>
  560. </div>
  561. <div class="paragraph">
  562. <p>Example:</p>
  563. </div>
  564. <div class="listingblock">
  565. <div class="content">
  566. <pre class="CodeRay highlight"><code data-lang="java"><span class="comment">/* This quaternion stores a 180 degree rolling rotation */</span>
  567. Quaternion roll180 = <span class="keyword">new</span> Quaternion();
  568. roll180.fromAngleAxis( FastMath.PI , <span class="keyword">new</span> Vector3f(<span class="integer">0</span>,<span class="integer">0</span>,<span class="integer">1</span>) );
  569. <span class="comment">/* The rotation is applied: The object rolls by 180 degrees. */</span>
  570. thingamajig.setLocalRotation( roll180 );</code></pre>
  571. </div>
  572. </div>
  573. <div class="paragraph">
  574. <p>So how to choose the right numbers for the Quaternion parameters? I&#8217;ll give you my cheat-sheet:</p>
  575. </div>
  576. <div class="paragraph">
  577. <p>+</p>
  578. </div>
  579. <table class="tableblock frame-all grid-all spread">
  580. <colgroup>
  581. <col style="width: 33.3333%;">
  582. <col style="width: 33.3333%;">
  583. <col style="width: 33.3334%;">
  584. </colgroup>
  585. <thead>
  586. <tr>
  587. <th class="tableblock halign-left valign-top"><strong>Rotation around Axis?</strong></th>
  588. <th class="tableblock halign-left valign-top"><strong>Use this Axis Vector!</strong></th>
  589. <th class="tableblock halign-left valign-top"><strong>Examples for this kind of rotation</strong></th>
  590. </tr>
  591. </thead>
  592. <tbody>
  593. <tr>
  594. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  595. <p>X axis</p>
  596. </div></div></td>
  597. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  598. <p>(1,0,0)</p>
  599. </div></div></td>
  600. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  601. <p>A plane pitches. Nodding your head.</p>
  602. </div></div></td>
  603. </tr>
  604. <tr>
  605. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  606. <p>Y axis</p>
  607. </div></div></td>
  608. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  609. <p>(0,1,0)</p>
  610. </div></div></td>
  611. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  612. <p>A plane yaws. A vehicle turns. Shaking your head.</p>
  613. </div></div></td>
  614. </tr>
  615. <tr>
  616. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  617. <p>Z axis</p>
  618. </div></div></td>
  619. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  620. <p>(0,0,1)</p>
  621. </div></div></td>
  622. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  623. <p>A plane rolls or banks. Cocking your head.</p>
  624. </div></div></td>
  625. </tr>
  626. </tbody>
  627. </table>
  628. <div class="paragraph">
  629. <p>+</p>
  630. </div>
  631. <div class="paragraph">
  632. <p>Note: These are the three most common examples – technically you can rotate around any axis expressed by a vector.</p>
  633. </div>
  634. <div class="paragraph">
  635. <p>+</p>
  636. </div>
  637. <table class="tableblock frame-all grid-all spread">
  638. <colgroup>
  639. <col style="width: 33.3333%;">
  640. <col style="width: 33.3333%;">
  641. <col style="width: 33.3334%;">
  642. </colgroup>
  643. <thead>
  644. <tr>
  645. <th class="tableblock halign-left valign-top"><strong>Angle?</strong></th>
  646. <th class="tableblock halign-left valign-top"><strong>Use Radians!</strong></th>
  647. <th class="tableblock halign-left valign-top"><strong>Examples</strong></th>
  648. </tr>
  649. </thead>
  650. <tbody>
  651. <tr>
  652. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  653. <p>45 degrees</p>
  654. </div></div></td>
  655. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  656. <p>FastMath.PI / 4</p>
  657. </div></div></td>
  658. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  659. <p>eighth of a circle</p>
  660. </div></div></td>
  661. </tr>
  662. <tr>
  663. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  664. <p>90 degrees</p>
  665. </div></div></td>
  666. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  667. <p>FastMath.PI / 2</p>
  668. </div></div></td>
  669. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  670. <p>quarter circle, 3 o&#8217;clock</p>
  671. </div></div></td>
  672. </tr>
  673. <tr>
  674. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  675. <p>180 degrees</p>
  676. </div></div></td>
  677. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  678. <p>FastMath.PI</p>
  679. </div></div></td>
  680. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  681. <p>half circle, 6 o&#8217;clock</p>
  682. </div></div></td>
  683. </tr>
  684. <tr>
  685. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  686. <p>270 degrees</p>
  687. </div></div></td>
  688. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  689. <p>FastMath.PI * 3 / 2</p>
  690. </div></div></td>
  691. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  692. <p>three quarter circle, 9 o&#8217;clock</p>
  693. </div></div></td>
  694. </tr>
  695. <tr>
  696. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  697. <p>360 degrees</p>
  698. </div></div></td>
  699. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  700. <p>FastMath.PI * 2</p>
  701. </div></div></td>
  702. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  703. <p>full circle, 12 o&#8217;clock emoji:wink</p>
  704. </div></div></td>
  705. </tr>
  706. <tr>
  707. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  708. <p><code>g</code> degrees</p>
  709. </div></div></td>
  710. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  711. <p>FastMath.PI * g / 180</p>
  712. </div></div></td>
  713. <td class="tableblock halign-left valign-top"><div><div class="paragraph">
  714. <p>any angle <code>g</code></p>
  715. </div></div></td>
  716. </tr>
  717. </tbody>
  718. </table>
  719. <div class="paragraph">
  720. <p>+</p>
  721. </div>
  722. <div class="paragraph">
  723. <p><strong>Important:</strong> You must specify angles in <a href="http://en.wikipedia.org/wiki/Radian">Radian</a>s (multiples or fractions of PI). If you use degrees, you will just get useless results.</p>
  724. </div>
  725. <div class="paragraph">
  726. <p>+</p>
  727. </div>
  728. <div class="paragraph">
  729. <p>How to use these tables to speficy a certain rotation:</p>
  730. </div>
  731. <div class="olist arabic">
  732. <ol class="arabic">
  733. <li>
  734. <p>Pick the appropriate vector from the axis table.</p>
  735. </li>
  736. <li>
  737. <p>Pick the appropriate radians value from the angle table.</p>
  738. </li>
  739. <li>
  740. <p>Create a Quaternion to store this rotation. <code>… fromAngleAxis( radians , vector )</code></p>
  741. </li>
  742. <li>
  743. <p>Apply the Quaternion to a node to rotate it. <code>… setLocalRotation(…)</code></p>
  744. </li>
  745. </ol>
  746. </div>
  747. <div class="paragraph">
  748. <p>Quaternion objects can be used as often as you want, so give them meaningfull names, like <code>roll90, pitch45, yaw180</code>.</p>
  749. </div>
  750. <div class="paragraph">
  751. <p><a href="http://gpwiki.org/index.php/OpenGL:Tutorials:Using_Quaternions_to_represent_rotation">More about Quaternions</a>…</p>
  752. </div>
  753. </div>
  754. </div>
  755. <div class="sect1">
  756. <h2 id="code-sample">Code Sample</h2>
  757. <div class="sectionbody">
  758. <div class="listingblock">
  759. <div class="content">
  760. <pre class="CodeRay highlight"><code data-lang="java"><span class="comment">/* We start out with a horizontal object */</span>
  761. Cylinder cylinder = <span class="keyword">new</span> Cylinder(<span class="string"><span class="delimiter">&quot;</span><span class="content">post</span><span class="delimiter">&quot;</span></span>, <span class="integer">10</span>, <span class="integer">10</span>, <span class="integer">1</span>, <span class="integer">10</span>);
  762. cylinder.setModelBound(<span class="keyword">new</span> BoundingBox());
  763. <span class="comment">/* Create a 90-degree-pitch Quaternion. */</span>
  764. Quaternion pitch90 = <span class="keyword">new</span> Quaternion();
  765. pitch90.fromAngleAxis(FastMath.PI/<span class="integer">2</span>, <span class="keyword">new</span> Vector3f(<span class="integer">1</span>,<span class="integer">0</span>,<span class="integer">0</span>));
  766. <span class="comment">/* Apply the rotation to the object */</span>
  767. cylinder.setLocalRotation(pitch90);
  768. <span class="comment">/* Update the model. Now it's vertical. */</span>
  769. cylinder.updateModelBound();
  770. cylinder.updateGeometry();</code></pre>
  771. </div>
  772. </div>
  773. </div>
  774. </div>
  775. <div class="sect1">
  776. <h2 id="interpolating-rotations">Interpolating Rotations</h2>
  777. <div class="sectionbody">
  778. <div class="paragraph">
  779. <p>You can specify two rotations, and then have jme calculate (interpolate) the steps between two rotations:</p>
  780. </div>
  781. <div class="ulist">
  782. <ul>
  783. <li>
  784. <p>com.jme3.math.Quaternion, slerp() – store an interpolated step between two rotations</p>
  785. <div class="ulist">
  786. <ul>
  787. <li>
  788. <p><a href="http://www.jmonkeyengine.com/doc/com/jme/math/Quaternion.html">com.jme.math.Quaternion</a></p>
  789. </li>
  790. <li>
  791. <p><a href="http://www.jmonkeyengine.com/doc/com/jme/math/TransformQuaternion.html">com.jme.math.TransformQuaternion</a></p>
  792. </li>
  793. </ul>
  794. </div>
  795. </li>
  796. </ul>
  797. </div>
  798. </div>
  799. </div>
  800. <div class="sect1">
  801. <h2 id="adding-rotations">"Adding" Rotations</h2>
  802. <div class="sectionbody">
  803. <div class="paragraph">
  804. <p>You can concatenate (add) rotations: This means you turn the object first around one axis, then around the other, in one step.</p>
  805. </div>
  806. <div class="paragraph">
  807. <p><code>Quaternion myRotation = pitch90.mult(roll45); /* pitch and roll */</code></p>
  808. </div>
  809. </div>
  810. </div>
  811. <div class="sect1">
  812. <h2 id="troubleshooting-rotations">Troubleshooting Rotations</h2>
  813. <div class="sectionbody">
  814. <div class="paragraph">
  815. <p>Does the object end up in an unexpected location, or at an unexpected angle? If you are getting weird results, check the following:</p>
  816. </div>
  817. <div class="olist arabic">
  818. <ol class="arabic">
  819. <li>
  820. <p>3-D transformations are non-commutative! This means it often makes a huge difference whether you first move a node and then rotate it around an axis, or first rotate the node around an axis and then move it. Make sure you code does what you mean to do.</p>
  821. </li>
  822. <li>
  823. <p>Are you intending to rotate around the object&#8217;s origin along an axis, or around another pivot point outside the object? If you are trying to <em>rotate an object around a pivot point</em>, you have to create an (invisible) pivot node first, and attach the object to it. Then apply the rotation to the <em>parental pivot node</em>, not to the child object itself!</p>
  824. </li>
  825. <li>
  826. <p>Did you enter the angle in degrees (0 - 360°) or radians (0 - 2*PI)? A 3D engine expects radians, so make sure to convert your values! Formula: <code>g° = FastMath.PI * g / 180</code></p>
  827. </li>
  828. </ol>
  829. </div>
  830. </div>
  831. </div>
  832. <div class="sect1">
  833. <h2 id="tip-transformation-matrix">Tip: Transformation Matrix</h2>
  834. <div class="sectionbody">
  835. <div class="paragraph">
  836. <p>This here is just about rotation, but there are three types of 3-D transformation: <a href="#">rotate</a>, <a href="scale.html">scale</a>, and <a href="translate.html">translate</a>.</p>
  837. </div>
  838. <div class="paragraph">
  839. <p>You can do all transformations in individual steps (and then update the objects geometry and bounds), or you can combine them and transform the object in one step. If you have a lot of repetitive movement going on in your game it&#8217;s worth learning more about Transformation Matrices for optimization. JME can also help you interpolate the steps between two fixed transformations.</p>
  840. </div>
  841. <div class="paragraph">
  842. <p>+</p>
  843. </div>
  844. <div class="ulist">
  845. <ul>
  846. <li>
  847. <p>com.jme3.math.Transform, interpolateTransforms() – interpolate a step between two transformations</p>
  848. <div class="ulist">
  849. <ul>
  850. <li>
  851. <p><a href="http://www.jmonkeyengine.com/doc/com/jme/math/TransformMatrix.html">com.jme.math.TransformMatrix</a></p>
  852. </li>
  853. </ul>
  854. </div>
  855. </li>
  856. </ul>
  857. </div>
  858. </div>
  859. </div>
  860. </div>
  861. <div id="footer">
  862. <div id="footer-text">
  863. Last updated 2016-05-21 23:44:18 UTC
  864. </div>
  865. </div>
  866. </body>
  867. </html>