请教关于设定透明的问题

shypzms

我画了个球，想把它设为透明，代码如下：

1. osg::Geode* geode = new osg::Geode();
   
2. osg::Sphere* sphere = new osg::Sphere(osg::Vec3(0.0f,0.0f,0.0f),1);
   
3. geode->addDrawable(new osg::ShapeDrawable(sphere));
   
4. osg::StateSet* state = geode->getOrCreateStateSet();
   
5. osg::BlendFunc* bf = new osg::BlendFunc();
   
6. bf->setSourceAlpha(osg::BlendFunc::CONSTANT_ALPHA);
   
7. bf->setDestinationAlpha(osg::BlendFunc::ONE_MINUS_CONSTANT_ALPHA);
   
8. state->setRenderingHint(osg::StateSet::TRANSPARENT_BIN);
   
9. state->setAttributeAndModes(bf, osg::StateAttribute::ON );
   
10. osg::Depth* depth = new osg::Depth;
    
11. state->setAttributeAndModes(depth, osg::StateAttribute::OFF );
    
12. osg::Group* root = new osg::Group();
    
13. root->addChild( geode );
    
14. osgViewer::Viewer* viewer = new osgViewer::Viewer();
    
15. root->setStateSet(state);
    
16. viewer->setSceneData(root);
    

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但是运行效果是这样的

tianxiao888

state->setAttributeAndModes(depth, osg::StateAttribute::OFF );

关闭深度测试怎么透明啊~~~晕

shypzms

state->setAttributeAndModes(depth, osg::StateAttribute::OFF );
改为ON一点效果也没有了，是不是要关闭深度缓存啊？

array

您的代码似乎表明您的想法很混乱。不要把透明效果和深度缓存扯上关系~~

其实只需要先设置模型的颜色Alpha值（例如setColor(Vec4(r,g,b,0.5))），然后设置Blend就可以了：

1. geode->getOrCreateStateSet()->setAttributeAndModes( new osg::BlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA) );

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当然TRANSPARENT_BIN也不错