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<div>Hi</div>
<div>Thank you for the reply.<br/>
<br/>
How do I proceed with a scalergradient and a Tetra?</div>
<div>Thank you</div>
<div> </div>
</div>
<div class="signature">Sayandeep Khan<br/>
<br/>
Student, M.Sc. Meteorologie<br/>
Meteorologiesches Institut der<br/>
Rheinische Friedrich-Wilhelms-Universität Bonn<br/>
<br/>
Wissenschaftlicher Beirat<br/>
Forschungsgemeinschaft Alternative Raumfahrt</div>
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<div name="quote" style="margin:10px 5px 5px 10px; padding: 10px 0 10px 10px; border-left:2px solid #C3D9E5; word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;">
<div style="margin:0 0 10px 0;"><b>Gesendet:</b> Freitag, 17. Juni 2016 um 00:58 Uhr<br/>
<b>Von:</b> "Cory Quammen" <cory.quammen@kitware.com><br/>
<b>An:</b> "Sean Con" <fluidandsolidearth@gmx.de><br/>
<b>Cc:</b> "vtkusers@vtk.org" <vtkusers@vtk.org><br/>
<b>Betreff:</b> Re: [vtkusers] VTKTetra opacity gradient [kind of emergency]</div>
<div name="quoted-content">Hi Sean,<br/>
<br/>
I think you are getting mixed up two definitions of the overloaded<br/>
term "gradient." It sounds like you want an opacity gradient. The<br/>
gradient referred to by volumeProperty.SetGradientOpacity refers to<br/>
setting opacity values according to the gradient of a scalar field in<br/>
the data set.<br/>
<br/>
In fact, what you want to do is define a scalar opacity function that<br/>
is transparent at one end and opaque at the other, then assign data<br/>
values to the points of your tetrahedron so that one end's value(s)<br/>
map to the transparent opacities in the scalar opacity function while<br/>
the other end's value(s) map to the opaque end of the scalar opacity<br/>
function.<br/>
<br/>
HTH,<br/>
Cory<br/>
<br/>
On Fri, Jun 17, 2016 at 12:07 AM, Sean Con <fluidandsolidearth@gmx.de> wrote:<br/>
> Hi all<br/>
><br/>
> Consider this :<br/>
><br/>
> # tetraheder #1<br/>
> unstructuredGrid = vtk.vtkUnstructuredGrid()<br/>
> unstructuredGrid.SetPoints(pointsLocal) # pointsLocal already<br/>
> defined<br/>
><br/>
> tetra= vtk.vtkTetra()<br/>
> tetra.GetPointIds().SetId(0,0)<br/>
> tetra.GetPointIds().SetId(1,1)<br/>
> tetra.GetPointIds().SetId(2,3)<br/>
> tetra.GetPointIds().SetId(3,4)<br/>
><br/>
> cellArray = vtk.vtkCellArray()<br/>
> cellArray.InsertNextCell(tetra)<br/>
> unstructuredGrid.SetCells(vtk.VTK_TETRA, cellArray)<br/>
><br/>
> unstructuredGrids.append(unstructuredGrid)<br/>
><br/>
> mapper = vtk.vtkDataSetMapper()<br/>
> mapper.SetInputData(unstructuredGrid)<br/>
> actor = vtk.vtkActor()<br/>
> actor.SetMapper(mapper)<br/>
> actors.append(actor)<br/>
><br/>
><br/>
><br/>
> So I have my tetrahedra<br/>
><br/>
> Now, I want to color the tetrahedra using opacity gradient. The top vetrx<br/>
> will have the solid color, the bottom triangluar plane will have complete<br/>
> transparency. I know I can use volumeProperty.SetGradientOpacity - but that<br/>
> only works with volumeProperty, not with vtktetra / dataset mapper.<br/>
><br/>
> Please help.<br/>
> Thank you<br/>
><br/>
><br/>
><br/>
> Sayandeep Khan<br/>
><br/>
> Student, M.Sc. Meteorologie<br/>
> Meteorologiesches Institut der<br/>
> Rheinische Friedrich-Wilhelms-Universität Bonn<br/>
><br/>
> Wissenschaftlicher Beirat<br/>
> Forschungsgemeinschaft Alternative Raumfahrt<br/>
><br/>
><br/>
><br/>
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<br/>
<br/>
<br/>
--<br/>
Cory Quammen<br/>
R&D Engineer<br/>
Kitware, Inc.</div>
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