void init(osg::Geometry* geom) { _geom = geom; _array = static_cast<osg::Vec3Array*>(geom->getVertexArray()); if (!_geom->getNumPrimitiveSets()) { _dw = new osg::DrawArrays(osg::PrimitiveSet::TRIANGLES,0,0); geom->addPrimitiveSet(_dw.get()); } else { _dw = dynamic_cast<osg::DrawArrays*>(_geom->getPrimitiveSet(_geom->getNumPrimitiveSets()-1)); } }