<?xml version="1.0" encoding="UTF-8"?> <!DOCTYPE html> <html lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <!-- qparameter.cpp --> <title>Parameter QML Type | Qt 3D 5.9</title> <link rel="stylesheet" type="text/css" href="style/offline-simple.css" /> <script type="text/javascript"> document.getElementsByTagName("link").item(0).setAttribute("href", "style/offline.css"); // loading style sheet breaks anchors that were jumped to before // so force jumping to anchor again setTimeout(function() { var anchor = location.hash; // need to jump to different anchor first (e.g. none) location.hash = "#"; setTimeout(function() { location.hash = anchor; }, 0); }, 0); </script> </head> <body> <div class="header" id="qtdocheader"> <div class="main"> <div class="main-rounded"> <div class="navigationbar"> <table><tr> <td >Qt 5.9</td><td ><a href="qt3d-index.html">Qt 3D</a></td><td ><a href="qt3d-core-qmlmodule.html">QML Types</a></td><td >Parameter QML Type</td></tr></table><table class="buildversion"><tr> <td id="buildversion" width="100%" align="right">Qt 5.9.4 Reference Documentation</td> </tr></table> </div> </div> <div class="content"> <div class="line"> <div class="content mainContent"> <div class="sidebar"> <div class="toc"> <h3><a name="toc">Contents</a></h3> <ul> <li class="level1"><a href="#properties">Properties</a></li> <li class="level1"><a href="#details">Detailed Description</a></li> </ul> </div> <div class="sidebar-content" id="sidebar-content"></div></div> <h1 class="title">Parameter QML Type</h1> <span class="subtitle"></span> <!-- $$$Parameter-brief --> <p>Provides storage for a name and value pair. This maps to a shader uniform. <a href="#details">More...</a></p> <!-- @@@Parameter --> <div class="table"><table class="alignedsummary"> <tr><td class="memItemLeft rightAlign topAlign"> Import Statement:</td><td class="memItemRight bottomAlign"> import Qt3D.Render 2.0</td></tr><tr><td class="memItemLeft rightAlign topAlign"> Instantiates:</td><td class="memItemRight bottomAlign"> <a href="qml-qt3d-render-parameter.html"><a href="qt3drender-qparameter.html">QParameter</a></td></tr></table></div><ul> <li><a href="qml-qt3d-render-parameter-members.html">List of all members, including inherited members</a></li> </ul> <a name="properties"></a> <h2 id="properties">Properties</h2> <ul> <li class="fn"><b><b><a href="qml-qt3d-render-parameter.html#name-prop">name</a></b></b> : QString</li> <li class="fn"><b><b><a href="qml-qt3d-render-parameter.html#value-prop">value</a></b></b> : QVariant</li> </ul> <!-- $$$Parameter-description --> <a name="details"></a> <h2 id="details">Detailed Description</h2> <p>A Parameter can be referenced by a <a href="qml-qt3d-render-renderpass.html">RenderPass</a>, Technique, Effect, Material, <a href="qml-techniquefilter.html">TechniqueFilter</a>, <a href="qml-renderpassfilter.html">RenderPassFilter</a>. At runtime, depending on which shader is selected for a given step of the rendering, the value contained in a Parameter will be converted and uploaded if the shader contains a uniform with a name matching that of the Parameter.</p> <pre class="cpp"> Parameter { name: <span class="string">"diffuseColor"</span> value: <span class="string">"blue"</span> } <span class="comment">// Works with the following GLSL uniform shader declarations</span> <span class="comment">// uniform vec4 diffuseColor;</span> <span class="comment">// uniform vec3 diffuseColor;</span> <span class="comment">// uniform vec2 diffuseColor;</span> <span class="comment">// uniform float diffuseColor;</span> </pre> <p><b>Note: </b>some care must be taken to ensure the value wrapped by a Parameter can actually be converted to what the real uniform expect. Giving a value stored as an int where the actual shader uniform is of type float could result in undefined behaviors.</p><p><b>Note: </b>when the targeted uniform is an array, the name should be the name of the uniform with [0] appended to it.</p><pre class="cpp"> Parameter { name: <span class="string">"diffuseValues[0]"</span> value: <span class="operator">[</span><span class="number">0.0</span><span class="operator">,</span> <span class="number">1.0.</span> <span class="number">2.0</span><span class="operator">,</span> <span class="number">3.0</span><span class="operator">,</span> <span class="number">4.0</span><span class="operator">,</span> <span class="number">883.0</span><span class="operator">,</span> <span class="number">1340.0</span><span class="operator">,</span> <span class="number">1584.0</span><span class="operator">]</span> } <span class="comment">// Matching GLSL shader uniform declaration</span> <span class="comment">// uniform float diffuseValues[8];</span> </pre> <p>When it comes to texture support, the Parameter value should be set to the appropriate <a href="qt3drender-qabstracttexture.html">texture</a> subclass that matches the sampler type of the shader uniform.</p> <pre class="cpp"> Parameter { name: <span class="string">"diffuseTexture"</span> value: Texture2D { <span class="operator">.</span><span class="operator">.</span><span class="operator">.</span> } } <span class="comment">// Works with the following GLSL uniform shader declaration</span> <span class="comment">// uniform sampler2D diffuseTexture</span> </pre> <p><b>See also </b><a href="qt3drender-qabstracttexture.html">Qt3DRender::QAbstractTexture</a>.</p> <!-- @@@Parameter --> <h2>Property Documentation</h2> <!-- $$$name --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="name-prop"> <td class="tblQmlPropNode"><p> <a name="name-prop"></a><span class="name">name</span> : <span class="type">QString</span></p></td></tr> </table></div> </div><div class="qmldoc"><p>Specifies the name of the parameter</p> </div></div><!-- @@@name --> <br/> <!-- $$$value --> <div class="qmlitem"><div class="qmlproto"> <div class="table"><table class="qmlname"> <tr valign="top" class="odd" id="value-prop"> <td class="tblQmlPropNode"><p> <a name="value-prop"></a><span class="name">value</span> : <span class="type">QVariant</span></p></td></tr> </table></div> </div><div class="qmldoc"><p>Specifies the value of the parameter</p> </div></div><!-- @@@value --> <br/> </div> </div> </div> </div> </div> <div class="footer"> <p> <acronym title="Copyright">©</acronym> 2017 The Qt Company Ltd. Documentation contributions included herein are the copyrights of their respective owners.<br> The documentation provided herein is licensed under the terms of the <a href="http://www.gnu.org/licenses/fdl.html">GNU Free Documentation License version 1.3</a> as published by the Free Software Foundation.<br> Qt and respective logos are trademarks of The Qt Company Ltd. in Finland and/or other countries worldwide. All other trademarks are property of their respective owners. </p> </div> </body> </html>