1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
|
/****************************************************************************
**
** 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/penguin
\title Loading a 3DS model with Qt3D
This tutorial shows how Qt3D can be used to load a simple
model object in 3D Studio Max (3DS) format with a perspective
camera view.
We start by defining a class that inherits from QGLView, which
provides some basic scene setup logic and 3D camera navigation:
\snippet qt3d/penguin/modelview.h class-defn
Refer first to the \l{Teapot Example} for the basics of using
the QGLView class, lighting and so on.
When the application starts up, we load the scene from its
resource file, and store the result in a member variable, so
we can refer to it in the paint function:
\snippet qt3d/penguin/modelview.cpp initialize
In the teapot example we had to specify appropriate effects but
the model loader sets appropriate effects on the scene for us.
\snippet qt3d/penguin/modelview.cpp paint
Here in the paint function we call the \c{draw()} function of
the scene's main object, in order to display the fully
loaded model.
This was really just two lines of code: one to load the model
(once off, when the application initialized) and another line to
display the model (every time the paint function is called).
\image penguin-0-screenshot.png
The result is pretty good for two lines of code, but it could
stand some improvements.
Here we are looking down onto the top of our penguin's head, and
even when we stand him on his feet, he is too close to the camera
to all fit in the frame.
Let's make a few changes to have our penguin display nicely
when the application opens.
\snippet qt3d/penguin_advanced/modelview.cpp initialize
First of all, let move the camera away from the penguin and up
so he fits in the frame and we can get a better angle on him,
when the application loads.
If use dragging and so on in the QGLView this will change the
camera from these intial settings, but this setup means the camera
will be well positioned at the moment the application opens.
We don't want to position the camera in the paintGL function,
because that would defeat QGLViews camera dragging features and
we would not be able to interact with the view properly.
We'll also save the main object away in a member variable so that
the overhead of searching the scene is not incurred every paint.
Finally a pose for our penguin is calculated - its a turn around the
x axis, so he is standing up on his feet; and a turn around the y
axis, so he shows a bit more of his profile. The pose is
calculated and stored as a quaternion - we want the x twist first
so that goes last in the product of the two quaternions.
\snippet qt3d/penguin_advanced/modelview.cpp paint
Now all that remains in the updated paint function is to apply the
new pose, and then paint the penguin.
\image penguin-screenshot.png
\l{qt3d-examples.html}{Return to Tutorials}.
*/
|
