<div dir="ltr">Hi Manjunath,<div><br></div><div>Sorry to take so long to get back to you.</div><div><br></div><div>Change</div><div><br></div><div><span style="font-size:12.8000001907349px">mapper.</span><span style="font-size:12.8000001907349px">SetScalarModeToUsePointData()</span><br></div><div><span style="font-size:12.8000001907349px"><br></span></div><div><span style="font-size:12.8000001907349px">to</span></div><div><span style="font-size:12.8000001907349px"><br></span></div><div><span style="font-size:12.8000001907349px">mapper.</span><span style="font-size:12.8000001907349px">SetScalarModeToUsePointFieldData()</span><span style="font-size:12.8000001907349px"><br></span></div><div><span style="font-size:12.8000001907349px"><br></span></div><div><span style="font-size:12.8000001907349px">The difference is subtle. The first call says to use the currently "active" scalar array. VTK has the concept of active attributes, which means that you can set one array in the point data arrays to be the active scalars. This concept is being used less and less, but it is still around, so it's worth knowing about. The call you had says to color by this array, but apparently there is no active array in the output of the NetCDF reader.</span></div><div><span style="font-size:12.8000001907349px"><br></span></div><div><span style="font-size:12.8000001907349px">The call I am suggesting (and which I tested with a sample NetCDF file) says to use the array named by mapper.SelectColorArray(varName) for coloring.</span></div><div><span style="font-size:12.8000001907349px"><br></span></div><div><span style="font-size:12.8000001907349px">HTH,</span></div><div><span style="font-size:12.8000001907349px">Cory</span></div></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Jul 2, 2015 at 8:25 AM, Manjunath K E <span dir="ltr"><<a href="mailto:ke.manjunath@gmail.com" target="_blank">ke.manjunath@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr"><div class="gmail_quote"><div dir="ltr"><div class="gmail_quote"><div dir="ltr"><div><div><div><div>Hi,<br></div><div><br></div>I am working on ocean data visualization. I have data in netCdf format.<br></div></div></div>I have written a code to read netcdf file and assign color for the input. Although, I am able to get grid display, but I am unable to get the coloring on it. <br><br>I have created lookup table for color mapping, but it is not working.. Please help me.<br></div><div>Following is my code...<br></div><div dir="ltr"><div>========================================================<br>from vtk import *<br><br>reader = vtkNetCDFCFReader()<br>reader.SetFileName("<a href="http://3d.nc" target="_blank">3d.nc</a>")<br>reader.SphericalCoordinatesOff()<br>#reader.SetOutputTypeToRectilinear()<br>reader.SetOutputType(6)#SetOutputTypeToRectilinear()<br>reader.SetReplaceFillValueWithNan(1)<br>reader.UpdateMetaData()<br>reader.Update()<br>reader.GetOutput().UpdateInformation()<br>output = reader.GetOutput()<br><br># find the range of the point scalars<br>a,b = reader.GetOutput().GetPointData().GetArray("SAL").GetRange()<br>nm = reader.GetOutput().GetPointData().GetArray("SAL").GetName()<br><br># show how to print a string in python, it is similar to C-style sprintf<br>print "Range of %s: %4.2f-%4.2f" %(nm,a,b)<br><br># transfer function (lookup table) for mapping point scalar data<br># to colors (parent class is vtkScalarsToColors)<br>lut = vtk.vtkColorTransferFunction()<br>lut.AddRGBPoint(a, 0.0, 0.0, 1.0)<br>lut.AddRGBPoint(a+(b-a)/4, 0.0, 0.5, 0.5)<br>lut.AddRGBPoint(a+(b-a)/2, 0.0, 1.0, 0.0)<br>lut.AddRGBPoint(b-(b-a)/4, 0.5, 0.5, 0.0)<br>lut.AddRGBPoint(b, 1.0, 0.0, 0.0)<br>lut.SetAlpha(0.5)<br><br>mapper = vtkDataSetMapper()<br>mapper.SetInputConnection(reader.GetOutputPort())<br>mapper.SetScalarModeToUsePointData()<br>mapper.SetLookupTable(lut)<br>mapper.SetScalarRange(a,b)<br>mapper.SelectColorArray("SAL");<br><br># the actor<br>myActor = vtkActor()<br>myActor.SetMapper( mapper )<br><br># renderer and render window <br>ren = vtkRenderer()<br>ren.SetBackground(1, 1, 1)<br>renWin = vtk.vtkRenderWindow()<br>renWin.SetSize(512, 512)<br>renWin.AddRenderer( ren )<br><br># render window interactor<br>iren = vtkRenderWindowInteractor()<br>iren.SetRenderWindow( renWin )<br><br># add the actors to the renderer<br>ren.AddActor( myActor )<br><br><br># render<br>renWin.Render()<br><br># initialize and start the interactor<br>iren.Initialize()<br>iren.Start()<br><br>======================================================<br><br><br clear="all"><div><div><div><div><div><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><div dir="ltr"><div><font color="#ff0000"> </font><font color="#ff6600">Thanks and Regards,</font></div><font color="#3366ff">Manjunath</font><br></div><div dir="ltr"><div><font color="#3366ff"> </font></div></div></div></div></div></div></div></div></div></div>
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<br></blockquote></div><br><br clear="all"><div><br></div>-- <br><div class="gmail_signature">Cory Quammen<br>R&D Engineer<br>Kitware, Inc.</div>
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