[vtk-developers] DoublePi proposal

[Bill Lorensen]

Andrew,

Looks to me like the Parametric classes are not being tested by VTK6

Bill

On Tue, May 15, 2012 at 6:47 PM, Andrew Maclean
<andrew.amaclean at gmail.com> wrote:
> Hi Bill, David,
>   As one of you pointed out earlier, the VTK Parametric classes will be
> affected by this change. In particular, the regression tests will
> fail due to the higher precision of Pi. I would only expect that the
> pictures for the regression tests would need to be updated.
>
> When I wrote these in conjunction with Will, I must admit I was frustrated
> that vtkMath::Pi only returned float. However I made a decision to use
> vtkMath::Pi rather than yet another constant for Pi in the hopes that this
> would change in the future. The greater precision should improve the look of
> some of the surfaces. E.g. the little imperfection at the pole of the
> ellipsoid should get smaller.
>
> Let me know if I can help in any way.
>
> When things settle, I will also update the PDF titled "Parametric Equations
> for Surfaces" in the documentation to VTK 6.
>
> Regards
>    Andrew
>
>
>
>>
>>
>> ---------- Forwarded message ----------
>> From: David Gobbi <david.gobbi at gmail.com>
>> To: Bill Lorensen <bill.lorensen at gmail.com>
>> Cc: VTK Developers <vtk-developers at vtk.org>
>> Date: Mon, 14 May 2012 16:38:37 -0600
>> Subject: Re: [vtk-developers] DoublePi proposal
>> Bill, the main reason that I put my patch on hold was that I wanted to
>> wait until VTK 6 had reached at least the same level of test coverage
>> as VTK 5.  I still think that this is a valid reason for keeping this
>> patch on hold.  The added pi precision will cause subtle changes in
>> many regression images, and some of the changes will be significant
>> enough to cause test failures.  That's great if all the regression
>> tests are running, because we can examine any test failures that occur
>> and replace the regression images as necessary.
>>
>> But right now in VTK 6, about half of our regression tests aren't
>> running.  So if this Pi patch is pushed now, we won't see all the
>> regression test failures immediately.  We'll see some regression test
>> failures some weeks (or months?) later as the various tests are
>> re-activated, and we won't be sure if the failures were caused by this
>> patch, or if they were caused by some other patch.
>>
>>  - David
>>
>>
>> On Mon, May 14, 2012 at 11:59 AM, David Gobbi <david.gobbi at gmail.com>
>> wrote:
>> > http://review.source.kitware.com/#/t/427/
>> >
>> >
>> > On Mon, May 14, 2012 at 10:50 AM, Bill Lorensen
>> > <bill.lorensen at gmail.com> wrote:
>> >> David,
>> >>
>> >> Can you point me to the gerrit topic? If not, I can start from scratch.
>> >>
>> >> Bill
>
> --
> ___________________________________________
> Andrew J. P. Maclean
>
> ___________________________________________



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