[vtkusers] is Vtk 5.2.1 64 bit clean?

[Berk Geveci]

>  Thorough testing of your extremely large data sets is well warranted. I'm
> not trying to take anything away from VTK. I think it is a wonderful toolkit
> that has allowed me to help people solve real problems. Just a word of
> caution that if your data sets start getting large (into 64 bit territory)
> be ready to possibly hunt down some bugs in the VTK code.

I would strongly encourage developers and users to report any issues
they find related to 64 bit issues when processing large datasets. We
are actively hunting such bugs. I want to clarify a few things:

* You will be in the "64 bit territory" when the number of points or
cells in your datasets is bigger than 2^31 (we use signed ints). It is
totally possible to have datasets much larger than 4 GiB without
exceeding 2^31 points/cells.

* Make sure to turn on VTK_USE_64BIT_IDS before compiling. This is OFF
by default. Without setting VTK_USE_64BIT_IDS to on, you cannot
process datasets that have more than 2^31 points/cells even on a 64
bit machine. When VTK_USE_64BIT_IDS is on, VTK will use a 64 bit
integer for indexing. Otherwise, it will use a 32 bit integer.

-berk


On Sat, Feb 14, 2009 at 11:16 PM, Michael Jackson
<mike.jackson at bluequartz.net> wrote:
> There are those issues and possible issues with 32 bit math results being
> placed into a 64 bit value such as the following:
>
> int x, y, z;
>
> int64 total = x * y * z;
>
> on the surface that looks fine, but what happens when x * y * z goes beyond
> the max signed int value? It rolls over and you get all sorts of weird
> errors.
>
>  I found and fixed a few of these last year and others have gone on the "64
> bit hunt" before but no one really sure just where the rest of the bugs are
> at.
>
>  Thorough testing of your extremely large data sets is well warranted. I'm
> not trying to take anything away from VTK. I think it is a wonderful toolkit
> that has allowed me to help people solve real problems. Just a word of
> caution that if your data sets start getting large (into 64 bit territory)
> be ready to possibly hunt down some bugs in the VTK code.
>
> ---
> Mike Jackson                 www.bluequartz.net
>
>
>
> On Feb 14, 2009, at 8:37 PM, shekharc wrote:
>
>> No, not atm. Perhaps that's why it works for me so far.
>>
>> Is it fair to say that 64-bit issues would crop up when say the array
>> lengths are like 2^32 or bigger (because of ints)? Other libraries (like
>> Blitz++) tend to have this issue too I believe.
>>
>> Cheers
>> Shakes
>>
>> Sean McBride wrote:
>>>
>>> On 2/13/09 12:58 PM, shekharc said:
>>>>
>>>> Works fine on Windows Vista/XP x64 and Linux x64 fine for me so far.
>>>
>>> Out of curiosity, are you using datasets > 4 GiB?
>
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