求解答：FBO问题

zxinxin0606

我现在要把一个不断更新的几何体这样的一个子场景用camera attach到一个纹理，然后将纹理贴到一个_quad上显示出来。这段程序在下面，但是不管我是直接attach纹理上还是image上全都是空的，不知道问题出在哪里，请求高人帮忙看看！！

         this->_quad=new osg::Geode;
        this->_quad->addDrawable(osg::createTexturedQuadGeometry(osg::Vec3(0.0,-100.0,0.0),osg::Vec3(100.0,0.0,0.0),osg::Vec3(0.0,0.0,100.0)));
       

        map->getOrCreateStateSet()->setMode(GL_LIGHTING,osg::StateAttribute::OFF);
       
        const osg::BoundingSphere& bs = map->getBound();
        float znear = 1.0f*bs.radius();
        float zfar  = 3.0f*bs.radius();
        // 2:1 aspect ratio as per flag geometry below.
        float proj_top   = 0.25f*znear;
        float proj_right = 0.5f*znear;

        this->_mapCamera=new osg::Camera;
                this->_mapCamera->setClearColor(osg::Vec4(0.1f,0.1f,0.3f,1.0f));
        this->_mapCamera->setClearMask(GL_COLOR_BUFFER_BIT|GL_DEPTH_BUFFER_BIT);
        this->_mapCamera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
        this->_mapCamera->setViewport(0,0,_width,_height);
        this->_mapCamera->setRenderOrder(osg::Camera:RE_RENDER);
        this->_mapCamera->setAllowEventFocus(false);
        this->_mapCamera->setRenderTargetImplementation(osg::Camera::FRAME_BUFFER_OBJECT);
        this->_mapCamera->setProjectionMatrixAsFrustum(-proj_right,proj_right,-proj_top,proj_top,znear,zfar);
        this->_mapCamera->setViewMatrixAsLookAt(bs.center()-osg::Vec3(0.0f,2.0f,0.0f)*bs.radius(),bs.center(),osg::Vec3(0.0f,0.0f,1.0f));
               
        _image=new osg::Image;
        _image->allocateImage(_width,_height,1,GL_RGBA, GL_UNSIGNED_BYTE);
        _image->setInternalTextureFormat(GL_RGBA);

        this->_binTex=new osg::TextureRectangle();
        //this->_binTex->setSourceFormat(GL_RGBA);
        //this->_binTex->setSourceType(GL_UNSIGNED_BYTE);
                this->_binTex->setInternalFormat(GL_RGBA);
        this->_binTex->setFilter(osg::Texture::MIN_FILTER, osg::Texture:INEAR);
        this->_binTex->setFilter(osg::Texture::MAG_FILTER, osg::Texture::LINEAR);
        this->_binTex->setTextureSize(_width,_height);

        this->_quad->getOrCreateStateSet()->setTextureAttributeAndModes(0,this->_binTex);
        this->_quad->getOrCreateStateSet()->setMode(GL_LIGHTING,osg::StateAttribute::OFF);
       
        this->_mapCamera->attach(osg::Camera::COLOR_BUFFER,_image);

               //更新几何体
        osg:rawable* mapGeom = map->getDrawable(0);
               osg::Geometry* mapgm = (osg::Geometry*)mapGeom;
        mapgm->setUpdateCallback(new GeometryCallback());

        //this->_mapCamera->setPostDrawCallback(new MyCameraPostDrawCallback(_image,this->_binTex,percent));

        this->_mapCamera->addChild(map);

        this->switchMap->addChild(this->_quad);

        this->switchMap->addChild(this->_mapCamera);

array

参看osgprerender例子即可，此外osg cookbook一书的源代码中也提供了好几个类似的例子

zxinxin0606

array 发表于 2012-3-20 09:24
参看osgprerender例子即可，此外osg cookbook一书的源代码中也提供了好几个类似的例子

恩  谢谢您。解决了！