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<?xml version="1.0" encoding="UTF-8" standalone="no"?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>7.8.  Perspective</title> <link rel="stylesheet" href="gimp-help-plain.css" type="text/css" /> <link rel="stylesheet" href="gimp-help-screen.css" type="text/css" /> <link rel="stylesheet" href="gimp-help-custom.css" type="text/css" /> <link rel="alternate stylesheet" href="gimp22.css" type="text/css" title="gimp22" /> <meta name="generator" content="DocBook XSL Stylesheets V1.73.2" /> <link rel="start" href="index.html" title="GNU Image Manipulation Program" /> <link rel="up" href="filters-light-and-shadow.html" title="7.  Light and Shadow Filters" /> <link rel="prev" href="script-fu-drop-shadow.html" title="7.7.  Drop Shadow" /> <link rel="next" href="script-fu-xach-effect.html" title="7.9.  Xach-Effect" /> </head> <body> <div class="navheader"> <table width="100%" summary="Navigation header"> <tr> <th colspan="3" align="center">7.8.  <span lang="en" xml:lang="en">Perspective</span> </th> </tr> <tr> <td width="20%" align="left"><a accesskey="p" href="script-fu-drop-shadow.html"><img src="../images/prev.png" alt="Prev" /></a> </td> <th width="60%" align="center">7.  <span lang="en" xml:lang="en">Light and Shadow Filters</span> </th> <td width="20%" align="right"> <a accesskey="n" href="script-fu-xach-effect.html"><img src="../images/next.png" alt="Next" /></a></td> </tr> </table> <hr /> </div> <div class="sect2" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h3 class="title"><a id="script-fu-perspective-shadow"></a>7.8.  <span lang="en" xml:lang="en">Perspective</span> </h3> </div> <div> <div class="revhistory"> <table border="1" width="100%" summary="Revision history"> <tr> <th align="left" valign="top" colspan="3"> <b>Revision History</b> </th> </tr> <tr> <td align="left">Revision $Revision: 2357 $</td> <td align="left">2007-10-06</td> <td align="left">ude</td> </tr> </table> </div> </div> </div> </div> <a id="id2745906" class="indexterm"></a> <a id="id2745924" class="indexterm"></a> <div class="sect3" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h4 class="title"><a id="id2745932"></a>7.8.1.  <span lang="en" xml:lang="en">Overview</span> </h4> </div> </div> </div> <div class="figure"> <a id="id2745943"></a> <p class="title"> <b>Figure 16.88.  <span lang="en" xml:lang="en"> Example for the “<span class="quote">Perspective</span>” filter </span> </b> </p> <div class="figure-contents"> <div class="mediaobject"> <img src="../images/filters/examples/perspective-shadow-orig.jpg" alt="Example for the Perspective filter" /> <div class="caption"> <p>Original image</p> </div> </div> <div class="mediaobject"> <img src="../images/filters/examples/perspective-shadow-applied.jpg" alt="Example for the Perspective filter" /> <div class="caption"> <p>“<span class="quote">Perspective</span>” applied</p> </div> </div> </div> </div> <br class="figure-break" /> <p> This filter adds a perspective shadow to the selected region or alpha-channel as a layer below the active layer. You may select color, length and direction of the shadow as well as the distance of the horizon. </p> <p> If necessary, the filter may resize the image. But it will not add a background to make the shadow visible. </p> </div> <div class="sect3" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h4 class="title"><a id="id2746026"></a>7.8.2.  <span lang="en" xml:lang="en">Activate the filter</span> </h4> </div> </div> </div> <p> You can access this filter in the image window menu through <span class="guimenu"><span class="accel">F</span>ilters</span> → <span class="guisubmenu"><span class="accel">L</span>ight and Shadow</span> → <span class="guimenuitem"><span class="accel">P</span>erspective</span>. </p> </div> <div class="sect3" lang="en" xml:lang="en"> <div class="titlepage"> <div> <div> <h4 class="title"><a id="id2746076"></a>7.8.3.  <span lang="en" xml:lang="en">Options</span> </h4> </div> </div> </div> <div class="figure"> <a id="id2746087"></a> <p class="title"> <b>Figure 16.89.  <span lang="en" xml:lang="en">“<span class="quote">Perspective</span>” options</span> </b> </p> <div class="figure-contents"> <div class="mediaobject"> <img src="../images/filters/options-light-perspective-shadow.png" alt="Perspective options" /> </div> </div> </div> <br class="figure-break" /> <div class="variablelist"> <dl> <dt> <span class="term">Angle</span> </dt> <dd> <p> The angle determines the direction of the shadow or the imaginary source of light, respectively. Values range from 0° to 180°, where 90° represents a light source just in front of the selection or layer. For angles less than 90°, the shadow is at the right side, so the light source is on the left. For angles greater than 90°, it's the other way round. Tip: think of the slider's handle as source of light. </p> <div class="figure"> <a id="id2746151"></a> <p class="title"> <b>Figure 16.90.  <span lang="en" xml:lang="en">“<span class="quote">Angle</span>” example</span> </b> </p> <div class="figure-contents"> <div class="mediaobject"> <img src="../images/filters/examples/perspective-shadow-angle15.png" alt="Angle example" /> <div class="caption"> <p>Angle 15°</p> </div> </div> <div class="mediaobject"> <img src="../images/filters/examples/perspective-shadow-default.png" alt="Angle example" /> <div class="caption"> <p>Angle 45° (default)</p> </div> </div> <div class="mediaobject"> <img src="../images/filters/examples/perspective-shadow-angle105.png" alt="Angle example" /> <div class="caption"> <p>Angle 105° (90° + 15°)</p> </div> </div> </div> </div> <br class="figure-break" /> </dd> <dt> <span class="term">Relative distance of horizon</span> </dt> <dd> <p> This option determines how far away the imaginary horizon is. The <span class="guilabel">relative distance</span> is the distance from the ground-line of the selection or layer, the “<span class="quote">unit</span>” of measurement is the height of the selection or layer. </p> <p> Value range is from 0.1 to 24.1, where 24.1 means (nearly) “<span class="quote">infinite</span>”. Note that the <span class="guilabel">relative length of shadow</span> must not exceed the distance of horizon. </p> <div class="figure"> <a id="id2746284"></a> <p class="title"> <b>Figure 16.91.  <span lang="en" xml:lang="en"> “<span class="quote">Distance of horizon</span>” example </span> </b> </p> <div class="figure-contents"> <div class="mediaobject"> <img src="../images/filters/examples/perspective-shadow-distance.png" alt="Distance of horizon example" /> <div class="caption"> <p> Angle = 45°. Distance = 2.4. Length = 1.8. </p> </div> </div> </div> </div> <br class="figure-break" /> <p> In the example above, the yellow area is the selection the filter is applied to. The blue line at the top represents the imaginary horizon. The angle between the selection's ground-line and the red line is 45°. The length of the red line is 1.8 times the height of the yellow selection. Extended to the horizon, the length is 2.4 times the selection's height. </p> </dd> <dt> <span class="term">Relative length of shadow</span> </dt> <dd> <p> With this option you can set the length of shadow with respect to the height of the selection or layer. In the above example, the red line represents the length of shadow, its length is 1.8 relative to the height of the yellow selection. </p> <p> Value range is from 0.1 to 24.1, although the length of shadow must not exceed the <span class="guilabel">relative distance of horizon</span> - you can't go beyond the horizon. </p> <div class="figure"> <a id="id2746383"></a> <p class="title"> <b>Figure 16.92.  <span lang="en" xml:lang="en">“<span class="quote">Length of Shadow</span>” example</span> </b> </p> <div class="figure-contents"> <div class="mediaobject"> <img src="../images/filters/examples/perspective-shadow-default.png" alt="Length of Shadow example" /> <div class="caption"> <p>Length = 1.0 (default)</p> </div> </div> <div class="mediaobject"> <img src="../images/filters/examples/perspective-shadow-length15.png" alt="Length of Shadow example" /> <div class="caption"> <p>Length = 1.5</p> </div> </div> </div> </div> <br class="figure-break" /> </dd> <dt> <span class="term">Blur radius</span> </dt> <dd> <p> After creating the shadow, a <a class="link" href="plug-in-gauss.html" title="2.3.  Gaussian Blur">Gaussian blur</a> with the specified radius is applied to the shadow layer, resulting in the realistic appearance of the shadow. </p> <div class="figure"> <a id="id2746472"></a> <p class="title"> <b>Figure 16.93.  <span lang="en" xml:lang="en">Blur example</span> </b> </p> <div class="figure-contents"> <div class="mediaobject"> <img src="../images/filters/examples/perspective-shadow-default.png" alt="Blur example" /> <div class="caption"> <p>Blur radius = 3 (default)</p> </div> </div> <div class="mediaobject"> <img src="../images/filters/examples/perspective-shadow-noblur.png" alt="Blur example" /> <div class="caption"> <p>Without blur (blur radius = 0)</p> </div> </div> </div> </div> <br class="figure-break" /> </dd> <dt> <span class="term">Color</span> </dt> <dd> <p> Of course, the default color of the shadow is black. But a click on the button opens the the color selector, where you may select any other color. </p> </dd> <dt> <span class="term">Opacity</span> </dt> <dd> <p> The shadow's opacity is the opacity of the new layer containing the shadow (see <a class="xref" href="gimp-image-combining.html#gimp-layer-properties" title="1.1.  Layer Properties">Section 1.1, “ <span lang="en" xml:lang="en">Layer Properties</span> ”</a>). It defaults to 80%, but you may select any other value from 0 (full transparency) to 100 (full opacity) here. After applying the filter to an image you can change the opacity in the <a class="link" href="gimp-dialogs-structure.html#gimp-layer-dialog" title="2.1.  Layers Dialog">layers dialog</a>. </p> </dd> <dt> <span class="term">Interpolation</span> </dt> <dd> <p> This drop-down list lets you choose the method of <a class="link" href="glossary.html#glossary-interpolation" title="Interpolation">interpolation</a> used when the shadow layer is transformed, for example rotated by the specified angle. Using <span class="guilabel">None</span> will usually result in aliasing, using any interpolation method may change the color of the shadow in some areas. <span class="guilabel">Linear</span> is a good choice. </p> </dd> <dt> <span class="term">Allow resizing</span> </dt> <dd> <p> If enabled, the filter will resize the image if that is needed to make place for the shadow. </p> <p> In the example below, the yellow area is the active selection, backgound is light blue. The white area has been added after resizing to make the shadow visible. </p> <div class="figure"> <a id="id2746659"></a> <p class="title"> <b>Figure 16.94.  <span lang="en" xml:lang="en">“<span class="quote">Allow resizing</span>” example</span> </b> </p> <div class="figure-contents"> <div class="mediaobject"> <img src="../images/filters/examples/perspective-shadow-resize.png" alt="Allow resizing example" /> <div class="caption"> <p>Allow resizing</p> </div> </div> <div class="mediaobject"> <img src="../images/filters/examples/perspective-shadow-noresize.png" alt="Allow resizing example" /> <div class="caption"> <p>Don't allow resizing</p> </div> </div> </div> </div> <br class="figure-break" /> </dd> </dl> </div> </div> </div> <div class="navfooter"> <hr /> <table width="100%" summary="Navigation footer"> <tr> <td width="40%" align="left"><a accesskey="p" href="script-fu-drop-shadow.html"><img src="../images/prev.png" alt="Prev" /></a> </td> <td width="20%" align="center"> <a accesskey="u" href="filters-light-and-shadow.html"> <img src="../images/up.png" alt="Up" /> </a> </td> <td width="40%" align="right"> <a accesskey="n" href="script-fu-xach-effect.html"><img src="../images/next.png" alt="Next" /></a></td> </tr> <tr> <td width="40%" align="left" valign="top"><a accesskey="p" href="script-fu-drop-shadow.html">7.7.  <span lang="en" xml:lang="en">Drop Shadow</span> </a> </td> <td width="20%" align="center"> <a accesskey="h" href="index.html"> <img src="../images/home.png" alt="Home" /> </a> </td> <td width="40%" align="right" valign="top"> <a accesskey="n" href="script-fu-xach-effect.html">7.9.  <span lang="en" xml:lang="en">Xach-Effect</span> </a></td> </tr> </table> </div> </body> </html> 
