[Paraview] Writing binary VTK

[Berk Geveci]

> I cannot write binary data to newer XML files since I understood that it has
> to be in base64 encoding and I wanted to export my data without using
> external libraries such as vtk. If there is an option to write binary xml
> files, I'd like to hear about it.

This is not true. If you using appended binary format, you do not need
the base64 encoding. You can write it raw binary. The only trick is
that the XML section stores position attributes that point to the
binary section. This requires a bit of book keeping when writing. For
more documentation on the XML format see:

http://www.vtk.org/Wiki/VTK_XML_Formats

For those that are willing to like VTK, we have bindings for C and
Fortran to write the XML based file formats.

Also, there is this fortran library:
http://stefano.zaghi.googlepages.com/lib_vtk_io. I haven't used it but
it look promising.

-berk

On Fri, Oct 31, 2008 at 4:22 AM, Ivo Roghair <ivoroghair at gmail.com> wrote:
> Hi,
>
> About one year ago, I got some C code from the VisIt site from LLNL, which
> allows you to write legacy (.vtk) files using quite easy-to-use wrapper
> functions. It writes both in ascii and binary and checks for correct endian.
> I googled for the filenames just now and found them here:
> http://www-vis.lbl.gov/Vignettes/SNAZ/visit_writer_float/
>
> I cannot write binary data to newer XML files since I understood that it has
> to be in base64 encoding and I wanted to export my data without using
> external libraries such as vtk. If there is an option to write binary xml
> files, I'd like to hear about it.
>
> Regards,
> Ivo
>
> Lester Anderson wrote:
>>
>> Hi Ken
>>  Thanks for the info. So is there an easy way to take the ascii data and
>> make it into a binary file (big-endian or ortherwise), or is it more
>> involved? Basically I have my data already it just needs converting.
>>  Cheers
>>  Lester
>>
>> > From: kmorel at sandia.gov
>> > To: lester_anderson1963 at hotmail.com; paraview at paraview.org
>> > Date: Thu, 30 Oct 2008 16:44:32 -0600
>> > Subject: Re: [Paraview] Writing binary VTK
>> >
>> > You have the basic idea for binary legacy VTK files. I think the one
>> > caveat
>> > is that the data needs to be written in big-endian format. (Someone
>> > correct
>> > me if I got that wrong.)
>> >
>> > I'm not sure what you mean by the column vs. sequential style. I think
>> > the
>> > data parts in ASCII data treat all whitespace the same, so you should be
>> > able to order the data in as many columns as you like.
>> >
>> > -Ken
>> >
>> >
>> > On 10/30/08 1:53 PM, "Lester Anderson" <lester_anderson1963 at hotmail.com>
>> > wrote:
>> >
>> > > Hello all
>> > >
>> > > I have got a really big dataset that I want to have in a binary
>> > > format. I have
>> > > the header information all sorted now, but want to know how to convert
>> > > the
>> > > data part to binary. From what I understand the binary VYK structure
>> > > is
>> > > basically the same as ascii except the data part is binary.
>> > >
>> > > On a second point, with an ascii VTK how can I change the data from a
>> > > huge
>> > > long column of data to the more sequential style shown in examples?
>> > >
>> > > I work on a PC
>> > >
>> > > thanks
>> > >
>> > > Lester
>> > >
>> > >
>> > > For the best free wallpapers from MSN Click here!
>> > > <http://wallpapers.msn.com/?ocid=[B001MSN42A0716B]>
>> >
>> >
>> > **** Kenneth Moreland
>> > *** Sandia National Laboratories
>> > ***********
>> > *** *** *** email: kmorel at sandia.gov
>> > ** *** ** phone: (505) 844-8919
>> > *** fax: (505) 845-0833
>> >
>> >
>> >
>>
>>
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