求助——自定义背景遮挡前景模型的问题

tao5730095

我想实现一个自定义背景， 当前面的模型被拖拽变化时背景不会变化。但现在的问题是模型被旋转时背景会遮挡部分模型。
      我的做法是先添加了一个Box，然后添加了一个HUD背景图片。（但HUD的camera只能设置为POST_RENDER，然后必须setClearMask（）不是默认的才可以显示图片。）最后设置了setRenderBinDetails顺序为先渲染背景后渲染Box。

下面是实现的代码：

1. 
   
2. osg::Group* groupBox = new osg::Group;
   
3. osg::Group* root = new osg::Group;
   
4. osg::Box* sp0 = new osg::Box(osg::Vec3(0.0001,0,0),2,3,0.2);
   
5. osg::ShapeDrawable* drawable0 = new osg::ShapeDrawable(sp0);
   
6. osg::Geode* geode0 = new osg::Geode();
   
7. geode0->addDrawable(drawable0);
   
8. groupBox->addChild(geode0);
   
9. 
   
10. osg::Camera* ca = new osg::Camera;
    
11. ca->setProjectionMatrix(osg::Matrix::ortho2D(0,650,0,700));
    
12. ca->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
    
13. ca->setRenderOrder(osg::Camera::POST_RENDER);
    
14. ca->setClearMask(GL_POLYGON_BIT);
    
15. 
    
16. osg::Geode* geode = new osg::Geode;
    
17. osg::Geometry* geometry = new osg::Geometry;
    
18. geode->addDrawable(geometry);
    
19. ca->addChild(geode);
    
20. osg::Vec3Array* vertices = new osg::Vec3Array;
    
21. vertices->push_back( osg::Vec3( 0, 0, -0) ); // 左下
    
22. vertices->push_back( osg::Vec3(0, 700, -0) ); // 左上
    
23. vertices->push_back( osg::Vec3(650,700,-0) ); // 右上
    
24. vertices->push_back( osg::Vec3( 650,0, -0) ); // 右下
    
25. geometry->setVertexArray(vertices);
    
26. osg::DrawElementsUInt* pyramidfront =
    
27.   new osg::DrawElementsUInt(osg::PrimitiveSet::QUADS, 0);
    
28. pyramidfront->push_back(3);
    
29. pyramidfront->push_back(2);
    
30. pyramidfront->push_back(1);
    
31. pyramidfront->push_back(0);
    
32. geometry->addPrimitiveSet(pyramidfront);
    
33. osg::Vec4Array* colors = new osg::Vec4Array;
    
34. colors->push_back(osg::Vec4(1.0f, 1.0f, 1.0f, 1.0f) ); //索引0 白色
    
35. osg::TemplateIndexArray
    
36.   <unsigned int, osg::Array::UIntArrayType,4,4> *colorIndexArray;
    
37. colorIndexArray = new osg::TemplateIndexArray<unsigned int, osg::Array::UIntArrayType,4,4>;
    
38. colorIndexArray->push_back(0);
    
39. colorIndexArray->push_back(0);
    
40. colorIndexArray->push_back(0);
    
41. colorIndexArray->push_back(0);
    
42. geometry->setColorArray(colors);
    
43. geometry->setColorIndices(colorIndexArray);
    
44. geometry->setColorBinding(osg::Geometry::BIND_PER_VERTEX);
    
45. osg::Vec2Array* texcoords = new osg::Vec2Array(4);
    
46. (*texcoords)[0].set(0.00f,0.0f);
    
47. (*texcoords)[1].set(0.00f,1.0f);
    
48. (*texcoords)[2].set(1.00f,1.0f);
    
49. (*texcoords)[3].set(1.00f,0.0f);
    
50. geometry->setTexCoordArray(0,texcoords);
    
51. osg::Texture2D* te5 = new osg::Texture2D(osgDB::readImageFile("E:\\data\\Images\\test.png"));
    
52. osg::StateSet* st5 = new osg::StateSet;
    
53. st5->setTextureAttributeAndModes(0,te5);
    
54. st5->setRenderBinDetails(-1,"RenderBin");
    
55. ca->setStateSet(st5);
    
56. 
    
57. groupBox->getOrCreateStateSet()->setRenderBinDetails(1,"RenderBin");
    
58. root->addChild(ca);
    
59. root->addChild(groupBox);
    
60. root->getOrCreateStateSet()->setMode(GL_LIGHTING, osg::StateAttribute::OFF);
    
61. 
    
62. osgViewer::Viewer viewer;
    
63. viewer.setSceneData(root);
    
64. viewer.run();
    

复制代码

array

这是一个绘制天空盒的例子，不过我想它同样适用于您的情况，您可以考虑将其改写：
http://lists.openscenegraph.org/ ... January/006201.html

tao5730095

2# array  用shader解决了，是深度值错误引起的。