[vtkusers] Update 4.4 to 5.0 problem!

[de Boer Ingo]

Hi John,

your modifications are perfect!! Thanks a lot!!

About the contribution of this class... All the honors
go to David. You should ask him. I think this is a good
contribution!

Because there is definitly a lack in VTK about the
color interpolation. You always have RGB interpolation,
allthough you select a colortable. This makes a wrong
representation of the data you have.

thanks & greets
  Ingo

---
Dr.-Ing. Ingo H. de Boer

Polytec GmbH
Polytec-Platz 1-7, 76337 Waldbronn, Germany
phone: ++49 7243 604 106
fax  : ++49 7243 604 255


> -----Original Message-----
> Subject: Re: [vtkusers] Update 4.4 to 5.0 problem!
> 
> 
> Ingo,
> 
> The problem lies in the Texture generator being a subclass of 
> vtkStructuredPointsSource - which is really supposed to be 
> obsolete. It has a flaw - in the old days, structured points 
> were generated slightly differently from imagedata because 
> the Extents were handled differently
> - in short, it calls input->Update() during the 
> executeInformation phase
> - this is so that when an output is generated, it can put 
> something sensible in the extents. However, this is what 
> causes the trouble in your case. The filter gets an update 
> and internally calls update again -
>   the way the new pipeline handles this is by giving you the 
> error you found.
> 
> Note that you are allowed to call update on an input by hand, 
> but you have to be careful about when you do it.
> 
> I've changed the class to be a subclass of vtkImageAlgorithm and 
> replaced the relevant pieces of RequestInformation and RequestData so 
> that they do the correct thing.
> 
> I've not tested it very well, but your demo runs. NB. I 
> removed the tif 
> file write by commenting it out because it looked like it was 
> there for 
> debug purposes.
> 
> Note 1 : In the request information, I've just stuck whatver texture 
> extents are available - strictly speaking we should ensure that the 
> lookuptable is uptodate, but I think this is already done. What this 
> means is that the information returned to the next filter could be 
> wroing - however this doesn't actually matter becas eth the 
> next filter 
> is a texture and it isn't checking the information anyway.
> 
> Note 2 : When you run this demo you'll get a warning message because 
> I've found a bug/feature with vtkTexture, which is that it doesn't 
> override vtkImageAlgorithm::Execute() which by default says "Put some 
> code in here to generate the data"
> In fact this is not necessary for vtkTexture and I'll fix it 
> (it doesn't 
> output anything anyway, just produces a texture)
> 
> In the meantime,
> 
> add to protected part of vtkTexture.h
>    // Override vtkImageAlgorithm warning message
>    virtual void ExecuteData(vtkDataObject *);
> and cpp
> //------------------------------------------------------------
> ----------------
> // We must overrride this to avoid vtkImageAlgorithm 
> producing a warning void vtkTexture::ExecuteData(vtkDataObject *) {
>    return;
> }
> //------------------------------------------------------------
> ----------------
> 
> enjoy
> 
> JB
> NB. I'm in the process of finalizing a vtkContrib repository 
> which this 
> class could be contributed to if you want.
> 
> 
> > Hi,
> > 
> > here comes a complete sample. (originally from David)
> > Anyone how can help translate this to 5.0/CVS code ?
> > 
> > greets
> >   Ingo
> > 
> > 
> >> -----Original Message-----
> >> Subject: [vtkusers] Update 4.4 to 5.0 problem!
> >>
> >>
> >> Hi,
> >>
> >> I have a problem with a class written by David Pont to solve a 
> >> problem concering the LookUpTable color interpolation.
> >>
> >> Now, I have updated VTK from 4.4 to 5.0.1 an have some
> >> trouble with it. I get the following error:
> >>
> >> ERROR: In .\vtkExecutive.cxx, line 783
> >> vtkStreamingDemandDrivenPipeline (01D6CBA8): UpdateData 
> >> invoked during another request. Returning failure to 
> >> algorithm vtkLookupTableToTexture(01D6C4A0).
> >>
> >> Any hints on this ?
> >> I guess I have to modify the class itself to make it work
> >> again, but I haven't a clue where to start. There is nothing 
> >> in the wiki how to upgrade classes form 4.4 to 5.0. The 
> >> webside search didn't bring any clues either.
> >>
> >> greets
> >>   Ingo
> >>
> >> ---
> >> Dr.-Ing. Ingo H. de Boer
> >>
> >> Polytec GmbH
> >> Polytec-Platz 1-7, 76337 Waldbronn, Germany
> >> phone: ++49 7243 604 106
> >> fax  : ++49 7243 604 255
> >>
> >>
> >> 
> ---------------------------------------------------------------------
> >> ---
> >>
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> 
> -- 
> John Biddiscombe,                            email:biddisco @ cscs.ch
> http://www.cscs.ch/about/BJohn.php
> CSCS, Swiss National Supercomputing Centre  | Tel:  +41 (91) 610.82.07
> Via Cantonale, 6928 Manno, Switzerland      | Fax:  +41 (91) 610.82.82
> 
>