camera->setViewport(0, 0, textureWH, textureWH);
camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
camera->setRenderOrder(osg::Camera::PRE_RENDER);
camera->setViewport(0, 0, textureWH, textureWH);
camera->setReferenceFrame(osg::Transform::ABSOLUTE_RF);
camera->setRenderOrder(osg::Camera::PRE_RENDER);