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diff --git a/doc/src/examples/nesting.qdoc b/doc/src/examples/nesting.qdoc deleted file mode 100644 index b4438bb8..00000000 --- a/doc/src/examples/nesting.qdoc +++ /dev/null @@ -1,134 +0,0 @@ -/**************************************************************************** -** -** Copyright (C) 2011 Nokia Corporation and/or its subsidiary(-ies). -** All rights reserved. -** Contact: Nokia Corporation (qt-info@nokia.com) -** -** This file is part of the QtQuick3D documentation of the Qt Toolkit. -** -** $QT_BEGIN_LICENSE:FDL$ -** GNU Free Documentation License -** Alternatively, this file may be used under the terms of the GNU Free -** Documentation License version 1.3 as published by the Free Software -** Foundation and appearing in the file included in the packaging of -** this file. -** -** Other Usage -** Alternatively, this file may be used in accordance with the terms -** and conditions contained in a signed written agreement between you -** and Nokia. -** -** -** -** -** $QT_END_LICENSE$ -** -****************************************************************************/ - -/*! - \example qt3d/nesting - \title Drawing into framebuffer objects - - The Nesting example shows how Qt3D can be used to draw into a - framebuffer object and then use the associated texture in - subsequent drawing operations. It is assumed that the reader - is already familar with the following examples: - - \list - \o \l{Teapot Example}{Hello Teapot} - drawing a basic object in 3D. - \o \l{Object Effects}{Cube} - applying transformations and materials to objects. - \endlist - - In this example we are going to draw two rotating and transparent - cubes. One cube will display a simple texture as in the - \l{Object Effects}{Cube} example, - and the other cube will display a nested scene containing a - rotating teapot. - - \image nesting-screenshot.png - - As with the other examples, we start by creating the geometric objects - we need in the constructor (we will share the cube geometry between - the two cubes we will be drawing): - - \snippet qt3d/nesting/cubeview.cpp 1 - - We also need three QPropertyAnimation objects to drive our - animations; rotation angle for the teapot, rotation angle for - the cube; orbit angle of the two cubes around each other: - - \snippet qt3d/nesting/cubeview.cpp 2 - - The final step in the constructor is to create a camera for - the nested scene we will be drawing into the framebuffer object. - This is in addition to the default QGLView::camera() object that - provides the camera for the main scene. - - \snippet qt3d/nesting/cubeview.cpp 3 - - To draw the nested scene, we of course need a framebuffer object, - which we create in the \c{initializeGL()} method: - - \snippet qt3d/nesting/cubeview.cpp 4 - - Note that we also set the framebuffer object on an instance of - QGLFramebufferObjectSurface. We will use this fact later when - we render the nested scene. - - For the other cube, we need a regular texture. And we'll also - turn on blending to make our cubes transparent: - - \snippet qt3d/nesting/cubeview.cpp 5 - - Now it is time to paint the scene in \c{paintGL()}. The first - thing we want to do is draw the teapot into the framebuffer object. - To do that, we need to establish a nested drawing state: - - \snippet qt3d/nesting/cubeview.cpp 6 - - In the code above, we first push the main scene's modelview and - projection matrices. And then we push a new drawing surface onto - the painter's surface stack. Everything we draw from now on will - be written to \c{fboSurface} and thus the framebuffer object. - To do that, we set the inner camera position, adjust the painter - state, clear the framebuffer object, and draw the teapot: - - \snippet qt3d/nesting/cubeview.cpp 7 - - Now that the nested scene has been drawn to the framebuffer object, - we pop the surface and matrix stacks to return to the main scene: - - \snippet qt3d/nesting/cubeview.cpp 8 - - Because our cubes are transparent, we need to make sure we draw - the objects in the scene from back to front. Otherwise the result - will not look correct. To do this, we check which of the cube - mid-points is furtherest away from the camera and draw that cube first - (the more negative the z value, the further away it is): - - \snippet qt3d/nesting/cubeview.cpp 9 - - Drawing the first cube with the simple texture is very similar to - the \l{Object Effects}{Cube} example: - - \snippet qt3d/nesting/cubeview.cpp 10 - - The main interesting wrinkle is that we draw the cube twice, - once with front faces culled, and the second time with back - faces culled. This effectively causes the cube to be drawn - back to front for proper blending. - - The second cube is drawn in a similar way except that we bind - the framebuffer object's texture to the state instead of a static - texture: - - \snippet qt3d/nesting/cubeview.cpp 11 - - Face culling is a simple way to draw transparent objects, but it - really only works on non-intersecting convex objects like our cubes. - For concave objects (like the teapot) or objects that intersect, - we would need to break the objects up into smaller convex pieces - and then order the pieces from back to front. - - \l{qt3d-examples.html}{Return to Examples}. -*/ |