{"id":11713,"date":"2025-03-03T14:45:22","date_gmt":"2025-03-03T13:45:22","guid":{"rendered":"https:\/\/www.basyskom.de\/?p=11713"},"modified":"2025-03-03T14:46:38","modified_gmt":"2025-03-03T13:46:38","slug":"3d-rendering-solutions-in-qt-an-overview","status":"publish","type":"post","link":"https:\/\/www.basyskom.de\/en\/3d-rendering-solutions-in-qt-an-overview\/","title":{"rendered":"3D Rendering Solutions in Qt – an Overview"},"content":{"rendered":"
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Qt’s 3D offering is changing, so we decided to look at different options for rendering 3D content in Qt.<\/p>\n

Qt itself offers not one, but two 3D rendering engines: Qt 3D<\/a> from our friends at KDAB\u00a0and Qt Quick 3D<\/a>. While the former has been removed as an official part of Qt<\/a> 6.9 onwards, the latter is only available under GPL and commercial licenses. Additionally, Qt Quick 3D is, as the name suggests, restricted to QML applications. If your application is based on QWidget, you have no choice but to look elsewhere.<\/p>\n

So we decided to test different 3D rendering solutions and how they integrate into the Qt world. To give a spoiler: There is no single perfect solution. The choice of framework always depends on the specific use case.<\/p>\n

Here, we investigate Coin 3D, Ogre, BGFX and Threepp. All of them are licensed permissively: Coin 3D and BGFX are licensed under BSD, Ogre and Threepp under MIT.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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Coin 3D<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
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Coin 3D<\/a> is a graphics API with the stated goal of being fully compatible with Open Inventor – a toolkit that has its roots in the early 1990s when Silicon Graphics Inc. (SGI) designed it to offer an abstraction layer on top of OpenGL.<\/p>\n

Open Inventor, and therefore Coin 3D, manages all scene objects – primitives, but also lights, materials, transforms, the camera – in a scene graph object. The scene descriptions can be loaded from *.iv files. Coin 3D even comes with not one but two Qt integration APIs: SoQt and Quarter, where the latter is more current and the one that the developers recommend to use.<\/p>\n

The following is a minimal example that renders a simple coin object inside a Quarter QWidget.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

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\/\/ https:\/\/www.coin3d.org\/quarter\/\n \n#include <QApplication>\n \n#include <Inventor\/nodes\/SoCone.h>\n#include <Inventor\/nodes\/SoSphere.h>\n#include <Inventor\/nodes\/SoCube.h>\n \n#include <Inventor\/nodes\/SoSeparator.h>\n#include <Inventor\/nodes\/SoGroup.h>\n \n#include <Inventor\/nodes\/SoMaterial.h>\n#include <Inventor\/nodes\/SoPerspectiveCamera.h>\n#include <Inventor\/nodes\/SoDirectionalLight.h>\n \n#include <Inventor\/nodes\/SoTranslation.h>\n#include <Inventor\/nodes\/SoTransform.h>\n#include <Inventor\/nodes\/SoRotationXYZ.h>\n \n#include <Quarter\/Quarter.h>\n#include <Quarter\/QuarterWidget.h>\n \nusing namespace Qt::StringLiterals;\nusing namespace SIM::Coin3D::Quarter;\n \nSoNode* createObjects()\n{\n \n    auto root = new SoSeparator;\n    root->ref();\n \n    auto camera = new SoPerspectiveCamera;\n \n \n    root->ref();\n    root->addChild(camera);\n    root->addChild(new SoDirectionalLight);\n \n    auto objGroup = new SoGroup();\n \n    auto coneMaterial = new SoMaterial;\n    coneMaterial->diffuseColor.setValue(0.5, 0.5, 0.0);\n    objGroup->addChild(coneMaterial);\n    objGroup->addChild(new SoCone());\n \n    auto sphereMaterial = new SoMaterial;\n    sphereMaterial->diffuseColor.setValue(0.7, 0.1, 0.1);\n    objGroup->addChild(sphereMaterial);\n    auto sphereTranslation = new SoTranslation;\n    sphereTranslation->translation.setValue(-3.0, 0.0, 0.0);\n    objGroup->addChild(sphereTranslation);\n    objGroup->addChild(new SoSphere());\n \n    auto boxMaterial = new SoMaterial;\n    boxMaterial->diffuseColor.setValue(0.1, 0.1, 0.75);\n    objGroup->addChild(boxMaterial);\n    auto boxTranslation = new SoTranslation;\n    boxTranslation->translation.setValue(3.0 * 2.0, 0.0, 0.0);\n    objGroup->addChild(boxTranslation);\n    objGroup->addChild(new SoCube());\n \n    SoRotationXYZ *yRotation = new SoRotationXYZ;\n    yRotation->axis = SoRotationXYZ::Y;\n    yRotation->angle = M_PI \/ 4.0;\n \n    SoRotationXYZ *xRotation = new SoRotationXYZ;\n    xRotation->axis = SoRotationXYZ::X;\n    xRotation->angle = M_PI \/ 8.0;\n \n    root->addChild(yRotation);\n    root->addChild(xRotation);\n \n    root->addChild(objGroup);\n \n    return root;\n}\n \nint main(int argc, char ** argv)\n{\n  QApplication app(argc, argv);\n \n  \/\/ Quater is Coins connection to Qt\n  Quarter::init();\n \n  auto rootNode = createObjects();\n  QuarterWidget * viewer = new QuarterWidget;\n  viewer->setSceneGraph(rootNode);\n  \/\/ Add some basic user interaction\n  viewer->setNavigationModeFile(QUrl(u"coin:\/\/\/scxml\/navigation\/examiner.xml"_s));\n \n  viewer->show();\n  app.exec();\n \n  \/\/ Clean\n  rootNode->unref();\n  delete viewer;\n  \n  Quarter::clean();\n  \n  return 0;\n} <\/code><\/pre>