public boolean sphereInFrustum(Vector3 center,float radius){
  for (int i=0; i < 6; i++)   if ((planes[i].normal.x * center.x + planes[i].normal.y * center.y + planes[i].normal.z * center.z) < (-radius - planes[i].d))   return false;
  return true;
}

public boolean sphereInFrustum ( Vector3 center , float radius ) { for ( int i = 0 ; i < 6 ; i ++ ) if ( ( planes [ i ] . normal . x * center . x + planes [ i ] . normal . y * center . y + planes [ i ] . normal . z * center . z ) < ( - radius - planes [ i ] . d ) ) return false ; return true ; }
returns wheter the given sphere is in the frustum .
