<div dir="ltr"><span style="font-size:14px">Hi </span><span style="font-size:14px">Sebastian,</span><div style="font-size:14px">                     I use the way about your method, but I get zero point. I may use wrong. Here is the code:</div><div style="font-size:14px"><div>       const float x = v1.x(); </div><div><span style="white-space:pre-wrap"> </span>const float y = v1.y(); </div><div><span style="white-space:pre-wrap">        </span>const float look_offSet = 10.0f;   </div><div><span style="white-space:pre-wrap">    </span>osg::ref_ptr<osgUtil::PolytopeIntersector> polyIt = new osgUtil::PolytopeIntersector(osgUtil::Intersector::PROJECTION, x - look_offSet , y - look_offSet, x + look_offSet, y + look_offSet ); </div><div><span style="white-space:pre-wrap">    </span>polyIt->setDimensionMask(osgUtil::PolytopeIntersector::DimZero);    // only pick points </div><div><br></div><div><span style="white-space:pre-wrap">  </span>osgUtil::IntersectionVisitor iv(polyIt ); </div><div><br></div><div><span style="white-space:pre-wrap">     </span>m_OSG->getViewer()->getCamera()->accept(iv);</div><div><span style="white-space:pre-wrap">    </span>osg::ref_ptr<osg::Vec3Array> v = new osg::Vec3Array;</div><div><br></div><div><span style="white-space:pre-wrap">      </span>if (polyIt->containsIntersections())    //this is <span style="background-color:rgb(255,0,0)">"false"    </span><span style="background-color:rgb(238,238,238)">Why???</span></div><div><span style="white-space:pre-wrap">      </span>{</div></div><div style="font-size:14px">                           .....</div><div style="font-size:14px">         }</div><div style="font-size:14px">cheers,</div><div style="font-size:14px">Bean</div></div>