[vtk-developers] Convenience methods for vtkCamera

[Aashish Chaudhary]

Hi David,

On Fri, Jul 22, 2011 at 10:19 AM, David Gobbi <david.gobbi at gmail.com> wrote:
> Hi Utkarsh,
> A method that takes a "const double [16]" argument for a matrix
> would be preferable, because it at least has strong precedent in
> VTK (e.g. in vtkMatrix4x4 and elsewhere).

I am making changes in accordance with the agreement in this mail.
Give me a day or so.

Thanks,


>  - David
>
> On Fri, Jul 22, 2011 at 7:44 AM, Utkarsh Ayachit
> <utkarsh.ayachit at kitware.com> wrote:
>>
>> David,
>>
>> I hear your objection, however not exposing such methods makes it
>> really complicated for applications like ParaView that use
>> client-server streams to update the objects. I do admit a method with
>> 16 arguments doesn't make sense. Instead something that takes a
>> double[16] would possibly be acceptable and does not cause any issues
>> for client-server streams.
>>
>> Utkarsh
>>
>>
>> On Thu, Jul 21, 2011 at 6:10 PM, David Gobbi <david.gobbi at gmail.com>
>> wrote:
>> > Hi Aashish,
>> > My objection is these methods are pure syntactic sugar.  They increase
>> > the weight of the VTK interface without adding any new capabilities.
>> > Also, if these methods are added here, they might entice people to add
>> > similar methods to vtkProp3D and elsewhere.
>> > I know that VTK is already rife with such methods, but at least in most
>> > cases they are implemented by macros to ensure that they are
>> > consistently
>> > applied throughout VTK.
>> > My own preference is interfaces that are austere and orthogonal.  I'm
>> > not
>> > even
>> > a fan of the Rotate() and SetPosition() methods of vtkActor, when
>> > vtkActor
>> > could have instead just had a SetTransform method and people could have
>> > used the Transform methods to modify the actor matrix.
>> >  - David
>> >
>> > On Thu, Jul 21, 2011 at 3:52 PM, Aashish Chaudhary
>> > <aashish.chaudhary at kitware.com> wrote:
>> >>
>> >> Hi David,
>> >>
>> >> On Thu, Jul 21, 2011 at 5:28 PM, David Gobbi <david.gobbi at gmail.com>
>> >> wrote:
>> >> > I noticed these two new methods in vtkCamera today, and if possible,
>> >> > I'd
>> >> > like for them to be removed:
>> >> >
>> >> >  void SetModelTransformMatrix( double x00,  double x01,  double
>> >> > x02, double
>> >> > x03,
>> >> >    double x10,  double x11,  double x12,  double x13,
>> >> >    double x20,  double x21,  double x22,  double x23,
>> >> >    double x30,  double x31,  double x32,  double x33);
>> >> >
>> >> >  void SetEyeTransformMatrix( double x00,  double x01,  double x02,
>> >> >  double
>> >> > x03,
>> >> >    double x10,  double x11,  double x12,  double x13,
>> >> >    double x20,  double x21,  double x22,  double x23,
>> >> >    double x30,  double x31,  double x32,  double x33);
>> >> >
>> >> > Is it really so hard to create a vtkMatrix4x4 and then pass it as an
>> >> > argument?
>> >>
>> >> No it is not. We added this as part of paraview - vtk stereo
>> >> integration. I will talk to Utkarsh (along with Nikhil) tomorrow to
>> >> figure out if we can remove them. Initially we didn't put them as I
>> >> didn't want to have something like this.
>> >>
>> >> I would though like to hear reasoning behind your objections. Said
>> >> that I am not favoring these two functions but would like to know what
>> >> you are thinking.
>> >>
>> >> > There is even a vtkMatrix4x4::DeepCopy method to make it easy to
>> >> > create
>> >> > a matrix from an array of doubles.
>> >>
>> >> Sure.
>> >>
>> >> >
>> >> > - David
>> >> >
>> >>
>> >>
>> >>
>> >> --
>> >> | Aashish Chaudhary
>> >> | R&D Engineer
>> >> | Kitware Inc.
>> >> | www.kitware.com
>



-- 
| Aashish Chaudhary
| R&D Engineer
| Kitware Inc.
| www.kitware.com