[vtkusers] XML format: base64 or raw

[fred]

Mathieu Malaterre wrote:
> Fixed in VTK CVS.
Ok, it works quite fine.

However, a little question ;-)

Say I have a VTK binary file.

-rw-r--r-- 1 fred users 203M 2007-02-22 21:35 E.vtk

I can use vtk2xml.py to convert it to XML binary or XML base64:

-rw-r--r-- 1 fred users 128M 2007-02-24 13:46 Ebase64.vtu
-rw-r--r-- 1 fred users  96M 2007-02-24 13:48 Ebin.vtu

Ebin.vtu is much smaller than Ebase64.vtu. Good.

Now, I use my own code. I get this:

-rw-r--r-- 1 fred users 128M 2007-02-24 13:27 Ebase64.vtu
-rw-r--r-- 1 fred users 128M 2007-02-24 13:50 Ebin.vtu

Here, the two files have the same size.

Ok, you think I missed something in my code ;-)

I used:

...
 vtkXMLWriterC_SetDataObjectType(writer, VTK_UNSTRUCTURED_GRID);
 vtkXMLWriterC_SetDataModeType(writer, VTK_XML_DATAMODE);
...

where VTK_XML_DATAMODE equals 1 or 2.

But:

cat Ebase64.vtu
<?xml version="1.0"?>
<VTKFile type="UnstructuredGrid" version="0.1" byte_order="LittleEndian" 
compressor="vtkZLibDataComp
ressor">
  <UnstructuredGrid>
    <Piece NumberOfPoints="2684385"              
NumberOfCells="2626560"             >
      <PointData Scalars="Ev" Vectors="E_vect">
        <DataArray type="Float32" Name="E_vect" NumberOfComponents="3" 
format="appended" RangeMin="0
"                    RangeMax="46.0918"              
offset="0"                   />
        <DataArray type="Float32" Name="Ev" format="appended" 
RangeMin="0"                    RangeM
ax="46.0918"              offset="37368952"            />
        <DataArray type="Float32" Name="Ex" format="appended" 
RangeMin="0"                    RangeM
ax="26.6113"              offset="49806368"            />
        <DataArray type="Float32" Name="Ey" format="appended" 
RangeMin="0"                    RangeM
ax="26.6108"              offset="62213160"            />
        <DataArray type="Float32" Name="Ez" format="appended" 
RangeMin="0"                    RangeM
ax="26.6113"              offset="74689940"            />
      </PointData>
      <CellData>
      </CellData>
      <Points>
        <DataArray type="Float32" Name="Array 0xc06f380" 
NumberOfComponents="3" format="appended" Ra
ngeMin="0"                    RangeMax="4.82659"              
offset="87103988"            />
      </Points>
      <Cells>
        <DataArray type="Int32" Name="connectivity" format="appended" 
RangeMin=""                  
  RangeMax=""                     offset="96797032"            />
        <DataArray type="Int32" Name="offsets" format="appended" 
RangeMin=""                     Ran
geMax=""                     offset="130440408"           />
        <DataArray type="UInt8" Name="types" format="appended" 
RangeMin=""                     Range
Max=""                     offset="134155548"           />
      </Cells>
    </Piece>
  </UnstructuredGrid>
  <AppendedData encoding="base64">

That sounds good.

cat Ebin.vtu:
<?xml version="1.0"?>
<VTKFile type="UnstructuredGrid" version="0.1" byte_order="LittleEndian" 
compressor="vtkZLibDataComp
ressor">
  <UnstructuredGrid>
    <Piece NumberOfPoints="2684385" NumberOfCells="2626560">
      <PointData Scalars="Ev" Vectors="E_vect">
        <DataArray type="Float32" Name="E_vect" NumberOfComponents="3" 
format="binary" RangeMin="0"
RangeMax="46.0918">

whereas Ebin.vtu created by vtk2xml.py looks like:
<VTKFile type="UnstructuredGrid" version="0.1" byte_order="LittleEndian" 
compressor="vtkZLibDataComp
ressor">
  <UnstructuredGrid>
    <Piece NumberOfPoints="2684385"              
NumberOfCells="2626560"             >
      <PointData Scalars="Ez" Vectors="E_vect">
        <DataArray type="Float32" Name="E_vect" NumberOfComponents="3" 
format="appended" RangeMin="0
"                    RangeMax="46.0918"              
offset="0"                   />
        <DataArray type="Float32" Name="Ez" format="appended" 
RangeMin="0"                    RangeM
ax="26.6113"              offset="28026714"            />
        <DataArray type="Float32" Name="Ev" format="appended" 
RangeMin="0"                    RangeM
ax="46.0918"              offset="37337247"            />
        <DataArray type="Float32" Name="Ex" format="appended" 
RangeMin="0"                    RangeM
ax="26.6113"              offset="46665306"            />
        <DataArray type="Float32" Name="Ey" format="appended" 
RangeMin="0"                    RangeM
ax="26.6108"              offset="55970398"            />
      </PointData>
      <CellData>
      </CellData>
      <Points>
        <DataArray type="Float32" Name="Array 0x82d4a50" 
NumberOfComponents="3" format="appended" Ra
ngeMin="0"                    RangeMax="4.82659"              
offset="65327981"            />
      </Points>
      <Cells>
        <DataArray type="Int32" Name="connectivity" format="appended" 
RangeMin=""                  
  RangeMax=""                     offset="72597763"            />
        <DataArray type="Int32" Name="offsets" format="appended" 
RangeMin=""                     Ran
geMax=""                     offset="97830293"            />
        <DataArray type="UInt8" Name="types" format="appended" 
RangeMin=""                     Range
Max=""                     offset="100616647"           />
      </Cells>
    </Piece>
  </UnstructuredGrid>
  <AppendedData encoding="raw">

which looks like better, no ?


What's the problem ?

Cheers,

-- 

/F