[vtkusers] why the color of actor is white by seting the vtkLookupTable

[Bill Lorensen]

Another idea. It seems that one pipeline piece is changing the cell
data. Try changing the mapper's input to determine which filter is the
culprit.

Try
mapper->SetInput(cube->GetOutput());
first.

Do you get the proper coloring?

bill


On Fri, Apr 16, 2010 at 3:39 PM, Bill Lorensen <bill.lorensen at gmail.com> wrote:
> Try,
> smoother->GenerateErrorScalarsOff() ;
>
> On Fri, Apr 16, 2010 at 1:30 AM, 朱文武 <cool.wenwu at gmail.com> wrote:
>> Bill, thanks very much !
>> Here are the all related codes:
>> vtkSmartPointer<vtkBMPReader> m_read = vtkSmartPointer<vtkBMPReader>::New();
>> m_read->SetFilePrefix("C:/Data/brain/TCVH_");//
>> m_read->SetFilePattern("%s%d.bmp"); //
>> m_read->Allow8BitBMPOn();
>> m_read->SetDataByteOrderToLittleEndian();
>> m_read->SetFileNameSliceOffset(5);//
>> m_read->SetFileNameSliceSpacing(1);//
>> m_read->SetNumberOfScalarComponents(3);//
>> m_read->SetDataOrigin(0.0,0.0,0.0);//
>> m_read->SetDataSpacing(0.167*4,0.167*4,1);//
>> m_read->SetDataExtent(0,299,0,345,1300,1320);//
>> m_read->Update();
>>
>> vtkSmartPointer<vtkDiscreteMarchingCubes> cube =
>>     vtkSmartPointer<vtkDiscreteMarchingCubes>::New() ;
>> cube->SetInput((vtkDataObject*) m_read->GetOutput() );
>> cube->SetValue(0, 111);
>> cube->SetValue(1, 121);
>> cube->Update() ;
>>
>> vtkSmartPointer<vtkDecimatePro>  deci =
>> vtkSmartPointer<vtkDecimatePro>::New();
>> deci->SetInputConnection(cube->GetOutputPort());//
>> deci->SetTargetReduction(0.5); //
>> deci->PreserveTopologyOn(); //
>> deci->ReleaseDataFlagOn();
>>
>> vtkSmartPointer<vtkWindowedSincPolyDataFilter> smoother=
>> vtkSmartPointer<vtkWindowedSincPolyDataFilter>::New();
>> smoother->SetInput(deci->GetOutput());
>> smoother->SetNumberOfIterations(30) ;
>> smoother->NonManifoldSmoothingOn();
>> smoother->NormalizeCoordinatesOn();
>> smoother->GenerateErrorScalarsOn() ;
>> smoother->Update();
>>
>> vtkSmartPointer<vtkLookupTable> colorLookupTable=
>> vtkSmartPointer<vtkLookupTable>::New();
>>
>> colorLookupTable->SetTableRange(0, 122);
>> colorLookupTable->SetNumberOfTableValues(123);
>> colorLookupTable->Build();
>> for (int i =0; i < 111; i++)
>> {
>>     colorLookupTable->SetTableValue(i , i/255.0, i/255.0,i/255.0);
>> }
>> colorLookupTable->SetTableValue(111, 1,0,0,1);
>> for (int j = 112; j <120; j++)
>> {
>>     colorLookupTable->SetTableValue(j , j/255.0, j/255.0, j/255.0);
>>
>> }
>> colorLookupTable->SetTableValue(121, 0,1,1,1);
>> colorLookupTable->SetTableValue(122, 0,1,1,1);
>>
>> vtkSmartPointer<vtkPolyDataNormals> triangleCellNormals =
>> vtkSmartPointer<vtkPolyDataNormals>::New();
>> triangleCellNormals->SetInput(smoother->GetOutput());
>> triangleCellNormals->ComputeCellNormalsOn();
>> triangleCellNormals->ComputePointNormalsOff();
>> triangleCellNormals->ConsistencyOn();
>> triangleCellNormals->AutoOrientNormalsOn();
>> triangleCellNormals->Update() ;
>>
>> vtkSmartPointer<vtkPolyDataMapper> mapper =
>> vtkSmartPointer<vtkPolyDataMapper>::New();
>> mapper->SetInput(triangleCellNormals->GetOutput()); // #this is better for
>> vis
>> mapper->ScalarVisibilityOn() ;//#show colour
>> mapper->SetScalarRange(colorLookupTable->GetTableRange());
>> mapper->SetScalarModeToUseCellData() ; //  contains the label eg. 31
>> //mapper->SetScalarModeToUsePointData() ;//#the smoother error relates to
>> the verts
>> mapper->SetLookupTable(colorLookupTable);
>>
>> vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();
>> actor->SetMapper(mapper);
>>
>> Waiting for suggestion, thanks in advance !
>>
>> Wenwu
>>
>>
>>
>> On Fri, Apr 16, 2010 at 12:01 PM, Bill Lorensen <bill.lorensen at gmail.com>
>> wrote:
>>>
>>> The lookup table and mapper look OK to me. Can you attach the entire
>>> program if it is not too large?
>>>
>>> Bill
>>>
>>> On Thu, Apr 15, 2010 at 9:00 PM, 朱文武 <cool.wenwu at gmail.com> wrote:
>>> > hi all,
>>> >
>>> >       I sent the message last night!  However, no one responded ! So, i
>>> > send
>>> > it again. Please forgive me, if it disrupts you!
>>> >
>>> > I use vtkDiscreteMarchingCubes to reconstruct anatomy structure, and use
>>> > the
>>> > vtkLookupTable to map the color. Now, i design the color map as follows:
>>> > gray value (111) to red,
>>> > gray value(121) to blue.
>>> > Other gray value I don't care.
>>> >
>>> > Also, the parameter I set in SetValue() of  vtkDiscreteMarchingCubes is:
>>> > SetValue(0, 111);
>>> > SetValue(1, 121);
>>> >
>>> > Then i set the lookup table as follows:
>>> > vtkSmartPointer<vtkLookupTable> colorLookupTable=
>>> > vtkSmartPointer<vtkLookupTable>::New();
>>> > colorLookupTable->SetTableRange(0, 122); //
>>> > colorLookupTable->SetNumberOfTableValues(123);
>>> > colorLookupTable->Build();
>>> >
>>> > for (int i =0; i < 111; i++)
>>> > {
>>> >     colorLookupTable->SetTableValue(i , i/255.0, i/255.0,i/255.0); // i
>>> > don't care this loop
>>> > }
>>> > colorLookupTable->SetTableValue(111, 1,0,0,1); // this is essential for
>>> > me
>>> > for (int j = 112; j <120; j++)
>>> > {
>>> >     colorLookupTable->SetTableValue(j , j/255.0, j/255.0, j/255.0); // i
>>> > don't care this loop
>>> >
>>> > }
>>> > colorLookupTable->SetTableValue(121, 0,0,1,1);
>>> > colorLookupTable->SetTableValue(122, 0,0,1,1);
>>> >
>>> > vtkSmartPointer<vtkPolyDataMapper> mapper =
>>> > vtkSmartPointer<vtkPolyDataMapper>::New();
>>> > ...
>>> > mapper->ScalarVisibilityOn() ;//#show colour
>>> > mapper->SetScalarRange(colorLookupTable->GetTableRange());
>>> > mapper->SetScalarModeToUseCellData() ;
>>> > mapper->SetLookupTable(colorLookupTable);
>>> >
>>> > The result of construction is that two structures whose gray value is
>>> > 111
>>> > and 121 were reconstructed.
>>> > However, the color of these actors is the same- white.
>>> > Ccould anyone tell me why and give some suggestions?
>>> >
>>> > Thanks
>>> > Wenwu
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>>> >
>>
>>
>>
>> --
>> 祝
>> 工作愉快，身体健康！
>>
>