[Paraview] new Source plugin: no show!

[B.W.H. van Beest]

Hi Burlen,

Thanks for your reply. On the cell-info:  I now (finally) understood
what was there to be. After implementing the cells, I indeed got the
expected display. On the book: what keeps me from buying is that it
seems outdated (because it refers to version 3).
The texture coordinates I had found on Google indeed. What I needed was
how to apply it in Paraview/VTK. I will look into that again Maybe it
becomes clear now.

Thanks
Bertwim
 
 
On 10/05/2014 05:05 AM, Burlen Loring wrote:
> I assume in your request data you are generating a vtkPolyData
> dataset. At the end of request data call "dataset->Print(cerr);" .
> That's the one of the best debug method when you don't see what you
> think you should in PV while developing a new filter/source/reader
> what ever. The information tab in the GUI gives a subset of that, also
> useful.
>
> texture coordinates are usually for applying an image to the surface.
> google it and you'll find volumes of info. In pv they are optional.
>
> the cell array I'm afraid is not. when generating poly or unstructured
> data. If you have no cells what do you expect to see?
>
> normals are per point.
>
> some of your questions suggest that the book VTK user guide
> <http://www.kitware.com/products/books/vtkguide.html> would be a good
> investment for you.
>
> Hope I didn't miss anything. ;-)
>
> On 10/4/2014 8:30 AM, B.W.H. van Beest wrote:
>> Hello,
>>
>> I need to write a new Source, representing a 'TriPrism",
>> i.e. a prism where the top and bottom planes are triangles. So far, I
>> failed.
>>
>> Being unable to find appropriate documentation, I used the source code
>> of vtkCubeSource as an example, thinking it would be an easy change.
>> Wrong! The prism doesn't show on the screen. The
>> properties panel behaves as expected (and ok, as far I can see).
>>
>> The member function 'RequestData' seems to be the important method.
>> But the code of the example (as well as other source examples) is on
>> closer inspection not clear to me at all.
>>
>> The following is happening in the vtkCubeSource:
>>
>> a)   The point of the cube are generated.  This is straightforward and
>> easily
>>         translates to the triprism.
>>        The new points are updated via a call "output->setPoints(
>> newPoints );"
>>
>> b)   The normals (to the side planes of the cube) are being calculated.
>>        The new normals are updated via a call
>>        "output->GetPointData()->SetNormals(newNormals);"
>>         This is also straightforward for the triprism, but:
>>
>>        Q: although calculating the normals is straightforward,
>>             in which order are they supposed to be given?
>>
>> c)     Also, texture coordinates (TCoords) are calculated.
>>          Q: What are these?  Are these mandatory?
>>
>> d)     Also, a new vtkCellArray is being created. ('newPolys')
>>           Q: Same question. No clue what I should do here.
>>
>> As usual, any clue of how to attack this is greatly appreciated.
>>
>> Bertwim
>>
>>
>>
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