/** compute, from normalized mouse coords, for sepecified Camera, the pixel coords relative to that Camera's RenderSurface.*/
bool computePixelCoords(float x,float y,unsigned int cameraNum,float& pixel_x,float& pixel_y);
/** compute, from normalized mouse coords, for sepecified Camera, the near and far points in worlds coords.*/
bool computeNearFar(float x,float y,unsigned int cameraNum,osg::Vec3& near, osg::Vec3& far);
/** compute, from normalized mouse coords, for sepecified Camera, intersections with the scene.*/
bool computeIntersections(float x,float y,unsigned int cameraNum,osgUtil::IntersectVisitor::HitList& hits);
/** compute, from normalized mouse coords, for all Cameras, intersections with the scene.*/
bool computeIntersections(float x,float y,osgUtil::IntersectVisitor::HitList& hits);