Rendering/vtkCamera.cxx
void vtkCamera::Roll(double angle)
{
  double newViewUp[3];
  this->Transform->Identity();

// rotate ViewUp about the Direction of Projection
  this->Transform->RotateWXYZ(angle,this->DirectionOfProjection);

// okay, okay, TransformPoint shouldn't be used on vectors -- but
// the transform is rotation with no translation so this works fine.
  this->Transform->TransformPoint(this->ViewUp,newViewUp);
  this->SetViewUp(newViewUp);
}
//----------------------------------------------------------------------------
// Rotate the camera around the view plane normal.
Rotate the camera around the view plane normal.
Rotate the camera around the view plane normal .
void vtkCamera::Roll(double angle)
{
  double newViewUp[3];
  this->Transform->Identity();
  this->Transform->RotateWXYZ(angle,this->DirectionOfProjection);
  this->Transform->TransformPoint(this->ViewUp,newViewUp);
  this->SetViewUp(newViewUp);
}
void vtkCamera :: Roll ( double angle ) { double newViewUp [ 3 ] ; this -> Transform -> Identity ( ) ; this -> Transform -> RotateWXYZ ( angle , this -> DirectionOfProjection ) ; this -> Transform -> TransformPoint ( this -> ViewUp , newViewUp ) ; this -> SetViewUp ( newViewUp ) ; }
Rotate the camera around the view plane normal.
Rotate the camera around the view plane normal .
// rotate ViewUp about the Direction of Projection // okay, okay, TransformPoint shouldn't be used on vectors -- but // the transform is rotation with no translation so this works fine.