[vtkusers] Crash with FixedPointVolumeRayCastMapper

[Mathieu Malaterre]

Antoine,

	Your feedback definitely narrows down the parameters, but it would be 
even more usefull if you could send us the backtrace of the crash. I'll 
assume you are running osirix compiled in Debug mode for that. Simply do:


$ gdb osirix
(gdb) run

... reload your usual volume ...
when your program hangs then simply do:

(gdb) bt

Thanks a lot
Mathieu


Antoine Rosset wrote:
> Hi,
> 
> Yes, this crash occurs repeatedly when I rotate the object: suddenly  it 
> crashes at a specific angle. It seems the function try to access  
> something outside the data memory zone.
> 
> Here are the parameters:
> 
> - float and unsigned char data (data is 512 x 512 x 51)
> - 1 or 4 components
> - with or without shading
> - with or without linear opacity function
> 
> The crashes are not influenced by these parameters.
> 
> If I replace the vtkFixedPointVolumeRayCastMapper function by  
> vtkVolumeRayCastMapper function, the crashes completely disappear.
> 
> BUT: if I change the reader->SetDataSpacing( 0.46875, 0.46875, 1.5)  
> function to reader->SetDataSpacing( 1, 1, 1); the crashes DISAPPEAR.
> 
> The library is compiled under MacOS X 10.4, dual-G5, 2 GB of RAM.
> 
> BTW: This new function accelerate renderings by a factor from 4 to 8  on 
> dual-PowerPC systems compared to vtkVolumeRayCastMapper. And  thanks for 
> the new RGB support!
> 
> Sincerely,
> 
> Antoine Rosset
> 
> <> <> <> <> <> <> <> <> <> <> <> <> <> <> <> <> <><> <>
> <> OSIRIX: Next Generation DICOM Viewer
> <> http://homepage.mac.com/rossetantoine/osirix
> <>
> <> Antoine ROSSET, M.D. (RossetAntoine at bluewin.ch)
> <> Blog : http://rossetantoine.blogspot.com/
> <> Geneva University Hospital - Radiology Department
> <> 20 Micheli-Du-Crest, CH-1205 Geneva
> <> Switzerland, Europe
> <> <> <> <> <> <> <> <> <> <> <> <> <> <> <> <> <><> <>
> 
> 
> On May 16, 2005, at 6:09 AM, Lisa Avila wrote:
> 
>> Hi Antoine,
>>
>> If you have some way of repeatedly causing the crash, I would love  to 
>> hear about it. Also, can you describe the type of data you are  
>> rendering (data type and number of components, along with the  options 
>> you've selected such as MIP vs. composite, was shading on?  Is the 
>> gradient opacity function not a constant 1?), and your system?
>>
>> Thanks,
>>
>> Lisa
> 
> 
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