* @param radius radius on pixel for clicking precision
* @return the distance in modelview world corresponding to radius pixel in screen
*/
// GLfloat getOrthoScreenRay(int x, int y, Geom::Vec3f& rayA, Geom::Vec3f& rayB, int radius=4) { return m_glWidget->getOrthoScreenRay(x,y,rayA,rayB,radius);}