[Paraview] Does vtkFixedPointVolumeRayCastMapper Work with Unsigned Char?

[Patrick Shinpaugh]

When I was running this data, I was using paraview-3.2.1 and 3.2.2. I 
haven't had much success with ParaView from CVS checked out 2008-06-27 
09:15. Seems to be unstable (crashes a lot) and only reason I checked it 
out was to access some time data which is accessible with the python 
interface for a study we are running.

paraview-3.2.2 should give you good results for the volume if that is 
all you are doing. I tried adding a single slice to the volume mentioned 
earlier and I waited more than an hour, watching top to see that it used 
up all available physical ram (~4GB) and 7.5GB of swap before the system 
crashed without a single update to the window. I also tried adding a 
threshold filter which had the same issue. This was on a 64 bit centos5 
machine, with python binding and openmpi though it was only running 
locally, built from scratch as a release build. Hopefully you won't have 
a similar issue if you try it out.



Kent Eschenberg wrote:
> Thanks, that is very helpful!
>
> I tried both the raw data and the VTK reader. I am sure I got the 
> bounds correct since, after passing the data through the Calculator, 
> the display was correct. Calculator merely changed the values from 
> char to double.
>
> I'm using ParaView from CVS on 6/25; which version are you using?
>
> Kent
>
> Patrick Shinpaugh wrote:
>> Yes, loaded a raw dataset (1024x943x50) of unsigned char. Visualized 
>> using volume (not sure which volume class I was using - whatever the 
>> default is). I did by mistake initially set the bounds 
>> 0-1024,0-943,0-50 which appeared to have the issue you mentioned 
>> (although it could have been that it appeared to have the minimum) 
>> until I realized that the bounds were incorrect.
>>
>>
>>
>> Kent Eschenberg wrote:
>>> Has anyone been able to use the ParaView volume visualization with 
>>> char or unsigned char data? In my test it seems to replace all data 
>>> values with the max. Using Calculator to first convert to double works.
>

-- 
Patrick Shinpaugh
Virginia Tech
UVAG System Administrator/Programmer
540-231-2054