[vtk-developers] Quadratic convenience classes in vtkUnstructuredGrid

[Soeren Gebbert]

Hi,

Mathieu Malaterre wrote:

> Hi Ken,
>
>  Indeed ! I believe you can track back the change to me at some point
> last year. One group (michelin, France) is using a sort of multi-UG to
> represent there tires. So they have multiple (= a lot!) vtkUG and they realize
> that performance was affected by that. Since they only use a limited
> subset of the available vtkCell in VTK and because you do not need
> explicit representation of a Cell they submited the patch.
>
>  the other cells were proposed by a vtk user, and I guess he
> implemented those classes at the time where vtkCell sublcasses would
> instanciate everything in the cstor.
>
It was me, and i think that was the case, but i cant remember correctly.

>  I believe this is safe to change the current behavior of the new
> Bi/Tri quad cell to copy the behavior of the older quad cell.
>
I agree with that. After changing the behavior, no problems appeared
with the new
(quadratic) cells.

btw:
The bug
Bug *#3691* - Contouring of new nonlinear cells incorrect
is still open. Does the fixes dont work?
Here are three screenshots
which will show the bug and the fix in paraview.

A plate made of vtkQuadraticLinearWedge's is clipped with the clipping
filter in paraviw 2.6:

The plate:
http://www-pool.math.tu-berlin.de/~soeren/VTK/Pictures/quad_lin_wedge_paraview.png

The clipped plate with current paraview 2.6 cvs version
http://www-pool.math.tu-berlin.de/~soeren/VTK/Pictures/quad_lin_wedge_clip_bug_in_paraview.png

The clipped plate with the fixed VTK sources in paraview 2.6 cvs version
http://www-pool.math.tu-berlin.de/~soeren/VTK/Pictures/quad_lin_wedge_clip_paraview_with_patch.png

Best regards
Soeren

> 2 cents,
> -Mathieu
>
>> On 5/21/07, Moreland, Kenneth <kmorel at sandia.gov> wrote:
>> > I was doing some debugging and noticed that several of the convenience
>> > vtkCell classes for some of the quadratic types (QuadraticLinearQuad,
>> > BiQuadraticQuad, etc.) are being instantiated in the vtkUnstructuredGrid
>> > constructor whereas all the others are set to NULL until used.  Is there
>> > a reason for this?
>> >
>> > -Ken
>> >
>> >    ****      Kenneth Moreland
>> >     ***      Sandia National Laboratories
>> > ***********
>> > *** *** ***  email: kmorel at sandia.gov
>> > **  ***  **  phone: (505) 844-8919
>> >     ***      fax:   (505) 845-0833
>> >
>> >
>> > _______________________________________________
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>> > vtk-developers at vtk.org
>> > http://www.vtk.org/mailman/listinfo/vtk-developers
>> >
>>
>>
>> --
>> Mathieu
>>
>
>