[Paraview] Fwd: saving screen shot as a PNG image, Paraview-3.8.0

[Rakesh Hammond]

---------- Forwarded message ----------
From: Rakesh Hammond <rakesh.hammond at googlemail.com>
Date: 13 August 2010 19:26
Subject: Re: [Paraview] saving screen shot as a PNG image, Paraview-3.8.0
To: pat marion <pat.marion at kitware.com>


Hi Pat,

Thanks for your suggestion - but didn't help, PV-3.8 still crashed.

I am able to save the screen shot using other formats (jpg, bmp etc).

I looked into it a little bit further and I think this is where its seg
faulting
(I am on 3.8 release branch, not the latest CVS)

in vtkPNGWriter.cxx

line 278 - the following for loop

 for (ui = 0; ui < height; ui++)
    {
    row_pointers[height - ui - 1] = (png_byte *)outPtr;
    outPtr = (unsigned char *)outPtr + rowInc;
    }

However, if I put a print statement inside the for loop(Hello world for
example), PV doesn't crash.  This may be due to a memory leak some where
else.

Can some one please comment on what sort of modifications I should make to
the above code?

I think this may be a nasty bug to recreate - has any one else encountered
this problem?

This is what I tried to do

start PV
Load some data
File->SaveScreenShot->
Now choose the .PNG format and my PV-3.8 crashes

Regards,


On 12 August 2010 19:26, pat marion <pat.marion at kitware.com> wrote:

> Hi Rakesh,
>
> In Edit -> Settings -> Render View there is an option "Use Offscreen
> Rendering for Screenshots."  On some systems, this option will cause a crash
> when enabled.
>
> Pat
>
> On Thu, Aug 12, 2010 at 1:42 PM, Rakesh Hammond <
> rakesh.hammond at googlemail.com> wrote:
>
>>  Hi
>>
>> I have a .pvti file which I can visualize in Paraview-3.8.0.
>>
>> I would like to save a slice from my data set and able to display the
>> results correctly.
>> However, when I select SaveScreen option with PNG format, it seg faults.
>>
>> I am able to get this to work correctly on 3.6.2 without seg faulting.
>>
>> I am on SuSe-10.2.
>>
>> Do I need to turn on the USE_SYSTEM_PNG flag in CMake and re-compile?
>> I haven't done this for 3.6.2 and works OK.
>>
>> Has any one else come across this problem before?
>>
>> Any pointers would be greatly appreciated.
>>
>> Regards,
>>
>> Rakesh
>>
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