[Paraview] visualising a network of tubes and spheres using python programmable filter

[Utkarsh Ayachit]

The tube filter only allows for using point data for scaling the
tubes. Another alternative is create two data sources one for the
sphere and one for the lines, and have duplicate points for the line
ends with appropriate point data to avoid the tapering. In the end you
can use AppendPolyData filter to append the two datasets into one.

Utkarsh

On Thu, Apr 16, 2009 at 4:41 AM, Sreejith Kuttanikkad
<sreejithpk at gmail.com> wrote:
> Dear all,
> On Wed, Apr 15, 2009 at 6:26 PM, Utkarsh Ayachit
> <utkarsh.ayachit at kitware.com> wrote:
>>
>> Read in the sphere radii and tube radii as point data on the dataset
>> that you are creating. Both the glyph filter and the tube filter has
>> options that allow you to scale the glyph (and the tube) by point
>> data.
>
> I have been trying many things but still not able to get what i wanted. For
> instance; please find a polydata xml file i created for a small cubic
> network (8 spheres and 12 tubes).
>
> <?xml version="1.0"?>
> <VTKFile type="PolyData" version="0.1" byte_order="LittleEndian">
> <PolyData>
> <Piece NumberOfPoints="8" NumberOfVerts="0" NumberOfLines="12"
> NumberOfStrips="0" NumberOfPolys="0">
> <Points>
> <DataArray type="Float32" NumberOfComponents="3" format="ascii">
> 0 0 0
> 1 0 0
> 0 1 0
> 1 1 0
> 0 0 1
> 1 0 1
> 0 1 1
> 1 1 1
> </DataArray>
> </Points>
> <Lines>
> <DataArray type="Int32" Name="connectivity" format="ascii">
> 0 1 2 3 0 2 1 3 4 5 6 7 4 6 5 7 0 4 1 5 2 6 3 7
> </DataArray>
> <DataArray type="Int32" Name="offsets" format="ascii">
> 2 4 6 8 10 12 14 16 18 20 22 24
> </DataArray>
> </Lines>
> <PointData Scalars="sph_dia">
> <DataArray type="Float32" Name="sph_dia" format="ascii">
>  2 5 6 8 9 4 3 8
> </DataArray>
> </PointData>
> </Piece>
> </PolyData>
> </VTKFile>
>
>
> If I read the above file with paraview and apply Glyph (sphere) and tube
> filter, I can view the network with spheres and tubes. If i choose the scale
> mode scalar and choose sph_dia, i can view spheres with different size.
> Similarly If i choose "vary radius" option to tubes, the size of the tube is
> varied based on the point data (sph_dia) and looks tapered (gradual change
> in size) as shown in the attachment. But that is not I wanted. I have tube
> diameter data and would like to be able to scale based on that and tube
> should have uniform diameter from one end to the other.  Please let me know
> if you have any suggestion or tips to attempt.
>
> thank you
> Sreejith
> IMFT Toulouse
>
>
>