inline G4bool G4AuxiliaryNavServices::CheckPointOnSurface( const G4VSolid* sampleSolid, 
			    const G4ThreeVector& localPoint, 
			    const G4ThreeVector* globalDirection, 
			    const G4AffineTransform& sampleTransform,
			    const G4bool  locatedOnEdge)
{
  G4ThreeVector localDirection, sampleNormal;
  G4bool enter=false;

  if (sampleSolid->Inside(localPoint)!=kOutside) 
    {
      if(locatedOnEdge && (globalDirection!=0))
	{
	  // We are probably located on an edge.
	  localDirection= sampleTransform.TransformAxis(*globalDirection); 
	  
	  // Check whether we enter the volume
	  // 
	  sampleNormal= sampleSolid->SurfaceNormal(localPoint);
	  if ( sampleNormal.dot(localDirection) <= 0 )
	    {
	      enter= true;
	    }
	}
      else
	{
	  enter= true;
	}
    }
  return enter;
}