求教Camera问题

sgdgoodboy

我用一个程序开了两个Window,然后用一个osgView 的viewer,slave了两个Camera,我的两个window这时显示的是一个视点的观察位置,并且控制一个窗口,这两个窗口的视点一起运动.(就是例子osgwindow那个两窗口的程序一样)

   我现在的问题是:我想运用两个camera 分别控制两个Window,并且让每个camera单独运动,不受其它窗口影响.
   老大们,我该怎么做啊?搞了好久啊,期待高手解决!

FlySky

这个就很容易实现了，，，你使用CompositeViewer就可以了～～～～分别对两个osgViewer::Viewer进行设置～～～～

刚改了下，，代码如下：

1. /* OpenSceneGraph example, osgwindows.
   
2. *
   
3. *  Permission is hereby granted, free of charge, to any person obtaining a copy
   
4. *  of this software and associated documentation files (the "Software"), to deal
   
5. *  in the Software without restriction, including without limitation the rights
   
6. *  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
   
7. *  copies of the Software, and to permit persons to whom the Software is
   
8. *  furnished to do so, subject to the following conditions:
   
9. *
   
10. *  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
    
11. *  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
    
12. *  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
    
13. *  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
    
14. *  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
    
15. *  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
    
16. *  THE SOFTWARE.
    
17. */
    
18. 
    
19. #include <osgDB/ReadFile>
    
20. #include <osgUtil/Optimizer>
    
21. #include <osgViewer/Viewer>
    
22. #include <osgViewer/CompositeViewer>
    
23. 
    
24. 
    
25. #include <iostream>
    
26. 
    
27. int main( int argc, char **argv )
    
28. {
    
29.     // use an ArgumentParser object to manage the program arguments.
    
30.     osg::ArgumentParser arguments(&argc,argv);
    
31. 
    
32.     // read the scene from the list of file specified commandline args.
    
33.     osg::ref_ptr<osg::Node> loadedModel = osgDB::readNodeFiles(arguments);
    
34. 
    
35.     // if not loaded assume no arguments passed in, try use default mode instead.
    
36.     if (!loadedModel) loadedModel = osgDB::readNodeFile("cow.osg");
    
37.    
    
38.     // if no model has been successfully loaded report failure.
    
39.     if (!loadedModel)
    
40.     {
    
41.         std::cout << arguments.getApplicationName() <<": No data loaded" << std::endl;
    
42.         return 1;
    
43.     }
    
44. 
    
45.     // construct the viewer.
    
46.     //osgViewer::Viewer viewer;
    
47. 
    
48.         osg::ref_ptr<osgViewer::CompositeViewer> viewer = new osgViewer::CompositeViewer();
    
49. 
    
50.         osg::ref_ptr<osgViewer::Viewer> viewer1= new osgViewer::Viewer() ;
    
51.         osg::ref_ptr<osgViewer::Viewer> viewer2= new osgViewer::Viewer() ;
    
52. 
    
53.     int xoffset = 40;
    
54.     int yoffset = 40;
    
55. 
    
56.     // left window + left slave camera
    
57.     {
    
58.         osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;
    
59.         traits->x = xoffset + 0;
    
60.         traits->y = yoffset + 0;
    
61.         traits->width = 600;
    
62.         traits->height = 480;
    
63.         traits->windowDecoration = true;
    
64.         traits->doubleBuffer = true;
    
65.         traits->sharedContext = 0;
    
66. 
    
67.         osg::ref_ptr<osg::GraphicsContext> gc = osg::GraphicsContext::createGraphicsContext(traits.get());
    
68. 
    
69.         osg::ref_ptr<osg::Camera> camera = new osg::Camera;
    
70.         camera->setGraphicsContext(gc.get());
    
71.         camera->setViewport(new osg::Viewport(0,0, traits->width, traits->height));
    
72.         GLenum buffer = traits->doubleBuffer ? GL_BACK : GL_FRONT;
    
73.         camera->setDrawBuffer(buffer);
    
74.         camera->setReadBuffer(buffer);
    
75. 
    
76.         // add this slave camera to the viewer, with a shift left of the projection matrix
    
77.         viewer1->addSlave(camera.get(), osg::Matrixd::translate(0.0,0.0,0.0), osg::Matrixd());
    
78. 
    
79.                 viewer1->setSceneData(osgDB::readNodeFile("cow.osg")) ;
    
80.     }
    
81.    
    
82.     // right window + right slave camera
    
83.     {
    
84.         osg::ref_ptr<osg::GraphicsContext::Traits> traits = new osg::GraphicsContext::Traits;
    
85.         traits->x = xoffset + 600;
    
86.         traits->y = yoffset + 0;
    
87.         traits->width = 600;
    
88.         traits->height = 480;
    
89.         traits->windowDecoration = true;
    
90.         traits->doubleBuffer = true;
    
91.         traits->sharedContext = 0;
    
92. 
    
93.         osg::ref_ptr<osg::GraphicsContext> gc = osg::GraphicsContext::createGraphicsContext(traits.get());
    
94. 
    
95.         osg::ref_ptr<osg::Camera> camera = new osg::Camera;
    
96.         camera->setGraphicsContext(gc.get());
    
97.         camera->setViewport(new osg::Viewport(0,0, traits->width, traits->height));
    
98.         GLenum buffer = traits->doubleBuffer ? GL_BACK : GL_FRONT;
    
99.         camera->setDrawBuffer(buffer);
    
100.         camera->setReadBuffer(buffer);
     
101. 
     
102.         // add this slave camera to the viewer, with a shift right of the projection matrix
     
103.        viewer2->addSlave(camera.get(), osg::Matrixd::translate(0.0,0.0,0.0), osg::Matrixd());
     
104. 
     
105.            viewer2->setSceneData(osgDB::readNodeFile("cow.osg")) ;
     
106.     }
     
107. 
     
108. 
     
109.         viewer->addView(viewer1.get()) ;
     
110.         viewer->addView(viewer2.get()) ;
     
111. 
     
112.     // optimize the scene graph, remove rendundent nodes and state etc.
     
113.     osgUtil::Optimizer optimizer;
     
114.     optimizer.optimize(loadedModel.get());
     
115. 
     
116.     // set the scene to render
     
117.    // viewer.setSceneData(loadedModel.get());
     
118. 
     
119.     return viewer->run();
     
120. }

复制代码

sky206

这个问题提的太及时了 :victory:

sgdgoodboy

非常感谢! 可是又有了新的问题,就是我用 camera的SetViewMetrix()做一些位置移动 和角度变换,在程序中怎么不变换呢?
    还有两个问题,就是用CompositeViewer,这个类没有done()函数,也就是说不能在while()循环中每桢来调用我想做的功能.是不是我用两个单独的viewer掉done()函数来做呢?
    另一个就是,我是在MFC下调用的这个程序,是用例子中的那种方式,但例子是用osgView类.就像你说用CompositeViewer的方式,在例子程序下改动的地方具体要怎么做呢?
    非常感谢,我又问了这么多问题.

array

原帖由 sgdgoodboy 于 2008-8-25 18:35 发表
非常感谢! 可是又有了新的问题,就是我用 camera的SetViewMetrix()做一些位置移动 和角度变换,在程序中怎么不变换呢?
    还有两个问题,就是用CompositeViewer,这个类没有done()函数,也就是说不能在while()循环中每桢 ...

setViewMatrix是可用的，关键是您在什么地方调用它。在回调中应该是可以的；在进入仿真循环之前执行的话，观察矩阵可能会被漫游器重置

CompositeViewer当然有done()函数。这个函数是ViewerBase的成员，而CompositeViewer和Viewer都是ViewerBase的派生类。还有就是done()函数的作用仅仅是判断是否退出仿真循环，更新和渲染工作都是在frame()函数中完成的（参见本站原创的教程《最长的一帧》）

在MFC中使用CompositeViewer的原理和使用Viewer是一样的，参考osgviewerMFC，注意这一次要提供给OSG两个窗口句柄hWnd，也就是要创建两个MFC窗口来承载视景器

[ 本帖最后由 array 于 2008-8-25 20:04 编辑 ]