[vtkusers] A problem to get the specified scalar data array I want

[Kenn Lin]

The two result screen shots intented to be presented in the former mail is
missing, sorry...

2012/4/24 Kenn Lin <cqqlin at gmail.com>

> Hello World:
>
> I got some problem when using 'SetInputArrayToProcess' to get the
> specified data I want, here's the details:
>
> I have an UnstructuredGrid data file(generated by opemfoam) in hand
> containing several arrays of scalar(temperature, pressure etc.) data and
> one array of vector(air current velocity) data of a room like this:
>
> # vtk DataFile Version 2.0
> outlet
> ASCII
> DATASET UNSTRUCTURED_GRID
> POINTS 116 float
> ......
> CELLS 57 285
> ......
> CELL_TYPES 57
> ......
> CELL_DATA 57
> FIELD attributes 6
> patchID 1 57 float
> ......
> p 1 57 float
> ......
> nut 1 57 float
> ......
> T 1 57 float
> ......
> k 1 57 float
> ......
> epsilon 1 57 float
> ......
> U 3 57 float
> ......
>
> POINT_DATA  116
> FIELD attributes 5
> p 1 116 float
> ......
> nut 1 116 float
> ......
> T 1 116 float
> ......
> k 1 116 float
> ......
> epsilon 1 116 float
> ......
> U 3 116 float
> ......
>
> Now I wish to visualize the array of "T"(Temperature) and "U"(Air current
> volocity), and after some efforts I achieved to visualize the latter one,
> which I thought may be the harder, by using a vtkGlyph3D and
> vtkArrowSource. I used 'glyp.SetInputArrayToProcess(1,0,0,0,"U")' to
> correctly specify the vector data array I want, it works.
>
> However, when I switch to specify the scalar data "T" using
> 'mapper.SetInputArrayToProcess(0,0,0,0,"T")', the program dose not work,
> seems to find no data to process in its pipeline.
>
> Below is the pipeline part of my code that can work with "volicity"
> visulization:
>
> vtkUnstructuredGridReader reader = new vtkUnstructuredGridReader();
> reader.setFileName(...);
>
> vtkCutter sliceCutter = new vtkCutter();
> vtkPlane slicePlane = new vtkPlane(); // slicePlane is controlled by a
> vtkImplicitPlaneWidget
> sliceCutter.SetCutFunction(slicePlane);
> sliceCutter.SetInput(reader.GetOutput());
>
> vtkArrowSource arrow= new vtkArrowSource();
> // ... some configuration of the arrow ...
>
> vtkGlyph3D glyp = new vtkGlyph3D();
> glyp.SetSource(arrow.GetOutput());
> glyp.SetInput(sliceCutter.GetOutput());
> glyp.SetInputArrayToProcess(1,0,0,0,"U"); // vectors
> glyp.SetScaleFactor(0.075);
> glyp.SetScaleFactor(10);
> glyp.SetColorModeToColorByVector();
> glyp.SetScaleModeToScaleByVector();
>
> sliceMapper = new vtkPolyDataMapper();
> sliceMapper.SetInput(glyp.GetOutput());
> ....
>
> The result is obvious:
>
>
> Below is the code that can not work with "temperature" visulization:
> (When it comes to scalar data "T", I removed the glyp3D, changed the
> pipeline simply to this:)
>
> vtkUnstructuredGridReader reader = new vtkUnstructuredGridReader();
> reader.setFileName(...)
> vtkCutter sliceCutter = new vtkCutter();
> vtkPlane slicePlane = new vtkPlane();
> sliceCutter.SetCutFunction(slicePlane);
> sliceCutter.SetInput(reader.GetOutput());
>
> sliceMapper = new vtkPolyDataMapper();
> sliceMapper.SetInput(sliceCutter.GetOutput());
>
> sliceMapper.SetInputArrayToProcess(0,0,0,0,"T"); // scalar
> // Here I also tried
> reader/sliceCutter.SetInputArrayToProcess(0,0,0,0,"T"), and even removed
> this sentence, only to get the same result.
>
> vtkActor sliceActor = new vtkActor();
> sliceActor.SetMapper(sliceMapper);
>
> The result is always a strange white plate:
>
>
> Could anyone tell me what's wrong with my scalar visualization pipeline or
> how to retrieve the specified scalar data I want?
>
> I uploaded the code files and data file as attachments. Due to the real
> temperature data file is really big, I replaced it with a smaller data file
> with the same data structure whose scalar data array is named 'p'.
>
> Really thanks very much for reading such a long question of mine :)
>
> --
> Sincerely,
> Kenn
>
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