请教：智能指针不能转化为普通指针的原因

bg417

编译错误：
错误 32 error C2664: “osg::Group::addChild”: 不能将参数 1 从“osg::ref_ptr<T>”转换为“osg::Node *”

tianxiao888

不能直接转把，应该用.get()得到

liuzhiyu123

使用Node.get()方法得到

树梢随风动

osg::ref_ptr<osg::Node> createBillboardTree(osg::ref_ptr<osg::Image> image);
virtual bool addChild( Node *child );

pat->addChild(createBillboardTree(image.get())) ;//此处遇到同样问题，不能将参数 1 从
//“osg::ref_ptr<T>”转换为“osg::Node *”
//若用Node.get()方法，具体代码怎么写呀。请高手指教

oman

一个是对象一个是指针当然不能这样转换

树梢随风动

回复 5# oman


   

1. #include <osgViewer/Viewer>
   
2. 
   
3. #include <osg/Node>
   
4. #include <osg/Geode>
   
5. #include <osg/Geometry>
   
6. #include <osg/Group>
   
7. #include <osg/Billboard>
   
8. #include <osg/Texture2D>
   
9. #include <osg/Image>
   
10. #include <osg/PositionAttitudeTransform>
    
11. #include <osg/MatrixTransform>
    
12. 
    
13. #include <osgDB/ReadFile>
    
14. #include <osgDB/WriteFile>
    
15. 
    
16. #include <osgUtil/Optimizer>
    
17. 
    
18. osg::ref_ptr<osg::Node> createBillboardTree(osg::ref_ptr<osg::Image> image)
    
19. {
    
20. //创建四边形
    
21. osg::ref_ptr<osg::Geometry> geometry = new osg::Geometry() ;
    
22. 
    
23. //设置顶点
    
24. osg::ref_ptr<osg::Vec3Array> v = new osg::Vec3Array() ;
    
25. v->push_back(osg::Vec3(-0.5f,0.0f,-0.5f)) ;
    
26. v->push_back(osg::Vec3(0.5f,0.0f,-0.5f)) ;
    
27. v->push_back(osg::Vec3(0.5f,0.0f,0.5f)) ;
    
28. v->push_back(osg::Vec3(-0.5f,0.0f,0.5f)) ;
    
29. 
    
30. geometry->setVertexArray(v.get()) ;
    
31. 
    
32. //设置法线
    
33. osg::ref_ptr<osg::Vec3Array> normal = new osg::Vec3Array() ;
    
34. normal->push_back(osg::Vec3(1.0f,0.0f,0.0f)^osg::Vec3(0.0f,0.0f,1.0f));
    
35. 
    
36. geometry->setNormalArray(normal.get()) ;
    
37. geometry->setNormalBinding(osg::Geometry::BIND_OVERALL) ;
    
38. 
    
39. //设置纹理坐标
    
40. osg::ref_ptr<osg::Vec2Array> vt = new osg::Vec2Array() ;
    
41. vt->push_back(osg::Vec2(0.0f,0.0f)) ;
    
42. vt->push_back(osg::Vec2(1.0f,0.0f)) ;
    
43. vt->push_back(osg::Vec2(1.0f,1.0f)) ;
    
44. vt->push_back(osg::Vec2(0.0f,1.0f)) ;
    
45. 
    
46. geometry->setTexCoordArray(0,vt.get()) ;
    
47. 
    
48. //绘制四边形
    
49. geometry->addPrimitiveSet(new osg::DrawArrays(osg::PrimitiveSet::QUADS,0,4)) ;
    
50. 
    
51. if(image.get())
    
52. {
    
53. //状态属性对象
    
54. osg::ref_ptr<osg::StateSet> stateset = new osg::StateSet() ;
    
55. 
    
56. //创建一个Texture2D属性对象
    
57. osg::ref_ptr<osg::Texture2D> texture = new osg::Texture2D() ;
    
58. //关联image
    
59. texture->setImage(image.get()) ;
    
60. //关联Texture2D纹理对象，第三个参数默认为ON
    
61. stateset->setTextureAttributeAndModes(0,texture.get(),osg::StateAttribute::ON) ;
    
62. //启用混合
    
63. stateset->setMode(GL_BLEND,osg::StateAttribute::ON);
    
64. //关闭光照
    
65. stateset ->setMode (GL_LIGHTING, osg::StateAttribute ::OFF) ;
    
66. 
    
67. geometry->setStateSet(stateset.get()) ;
    
68. }
    
69. 
    
70. //创建Billboard对象一
    
71. osg::ref_ptr<osg::Billboard> billboard1 = new osg::Billboard() ;
    
72. 
    
73. //设置旋转模式为绕视点
    
74. billboard1->setMode(osg::Billboard::POINT_ROT_EYE) ;
    
75. //添加Drawable，并设置其位置，默认位置为osg::Vec3(0.0f,0.0f,0.0f) ;
    
76. billboard1->addDrawable(geometry.get(),osg::Vec3(5.0f,0.0f,0.0f)) ;
    
77. 
    
78. osg::ref_ptr<osg::Billboard> billboard2 = new osg::Billboard() ;
    
79. //设置旋转模式为绕轴转，因此还需要设置转轴
    
80. billboard2->setMode(osg::Billboard::AXIAL_ROT) ;
    
81. //设置旋转轴
    
82. billboard2->setAxis(osg::Vec3(0.0f,0.0f,1.0f)) ;
    
83. billboard2->addDrawable(geometry.get(),osg::Vec3(10.0f,0.0f,0.0f)) ;
    
84. 
    
85. osg::ref_ptr<osg::Group> billboard = new osg::Group() ;
    
86. billboard->addChild(billboard1.get()) ;
    
87. billboard->addChild(billboard2.get()) ;
    
88. 
    
89. return billboard.get() ;
    
90. 
    
91. }
    
92. 
    
93. int main()
    
94. {
    
95. osg::ref_ptr<osgViewer::Viewer> viewer = new osgViewer::Viewer() ;
    
96. 
    
97. osg::ref_ptr<osg::Group> root = new osg::Group() ;
    
98. 
    
99. //读取图像
    
100. osg::ref_ptr<osg::Image> image =osgDB::readImageFile("Images/tree0.rgba") ;
     
101. 
     
102. //缩放一下，以达到合适的大小
     
103. osg::ref_ptr<osg::PositionAttitudeTransform> pat = new osg::PositionAttitudeTransform() ;
     
104. pat->setScale(osg::Vec3(5.0f,5.0f,5.0f)) ;
     
105. pat->addChild(createBillboardTree(image.get()));
     
106. 
     
107. root->addChild(pat.get()) ;
     
108. 
     
109. //读取cow的模型，以对比
     
110. root->addChild(osgDB::readNodeFile("cow.osg"));
     
111. 
     
112. //优化场景数据
     
113. osgUtil::Optimizer optimizer ;
     
114. optimizer.optimize(root.get()) ;
     
115. 
     
116. viewer->setSceneData(root.get()) ;
     
117. 
     
118. viewer->realize() ;
     
119. 
     
120. viewer->run() ;
     
121. 
     
122. return 0 ;
     
123. 
     
124. }

复制代码

这是全部的代码。osg::ref_ptr<>这个运用的是智能指针。osg::ref_ptr<osg::Node>不就是相当于osg::Node *吗？如果不是怎么改呀

array

在另一个帖子里已经回复您了，只是在末尾加一个.get()而已，何必重复发帖询问