Hi, David,<br><br>Thank you for your reply.<br><br>Yes, the code clip I attached is building a polydata object for the landmarks only and there is another polydata object for the surface.<br><br>What I want to make is the landmarks are drawn on the screen while another surface is show. However, when the application runs, only the surface is shown, the landmarks are never appreared. I tried to change the z-coordinate by hand, but they still don't appear.<br>
<br>Could it be anything wrong with the visualization pipeline? I think I've accomplish the basic operation to visualize actors in the code clip.<br><br>Thank you for your kind helpӣ<br><br>Wenlong<br><br><div class="gmail_quote">
2011/10/11 David E DeMarle <span dir="ltr"><<a href="mailto:dave.demarle@kitware.com">dave.demarle@kitware.com</a>></span><br><blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
You have to have as many tuples in the scalars array as there are<br>
points in the polydata. You have only as many tuples as there are<br>
landmark points.<br>
<br>
Alternatively might make another polydata that contains only the<br>
landmark points and draw both polydata. Scale the landmark polydata up<br>
slightly to avoid z-tearing.<br>
<br>
David E DeMarle<br>
Kitware, Inc.<br>
R&D Engineer<br>
21 Corporate Drive<br>
Clifton Park, NY 12065-8662<br>
Phone: <a href="tel:518-881-4909" value="+15188814909">518-881-4909</a><br>
<div><div></div><div class="h5"><br>
<br>
<br>
On Tue, Oct 11, 2011 at 9:17 AM, Wenlong Wang <<a href="mailto:scc.wwl@gmail.com">scc.wwl@gmail.com</a>> wrote:<br>
> Dear all,<br>
><br>
> Is there anyone know how to change the color of points with specific point<br>
> ID?<br>
><br>
> I do it like this, but the surface appeared but none of these point is<br>
> shown.<br>
><br>
> Here is the code,<br>
><br>
> vtkPoints* newpoints = vtkPoints::New();<br>
> for (int i = 0; i < sizeof(landmarks)/sizeof(double); i++)<br>
> {<br>
> double temp_point[3];<br>
> points->GetPoint(vtkIdType(landmarks[i]), temp_point);<br>
> newpoints->InsertPoint(vtkIdType(i), temp_point[0], temp_point[1],<br>
> temp_point[2]);<br>
> }<br>
><br>
> vtkPolyData* newpolydata = vtkPolyData::New();<br>
> newpolydata->SetPoints(newpoints);<br>
><br>
> vtkFloatArray* newarray = vtkFloatArray::New();<br>
> for (int i = 0; i < sizeof(landmarks)/sizeof(double); i++)<br>
> {<br>
> newarray->InsertTuple1(vtkIdType(i), double(i));<br>
> }<br>
><br>
> newpolydata->GetPointData()->SetScalars(newarray);<br>
><br>
> vtkPolyDataMapper* newmapper = vtkPolyDataMapper::New();<br>
> newmapper->SetInput(newpolydata);<br>
> newmapper->SetScalarRange(0, 7);<br>
> newmapper->SetScalarVisibility(0);<br>
><br>
> vtkActor* newactor = vtkActor::New();<br>
> newactor->SetMapper(newmapper);<br>
> newactor->GetProperty()->SetColor(0.0, 1.0, 0.0);<br>
> newactor->GetProperty()->SetPointSize(3);<br>
><br>
> ren->AddActor(newactor);<br>
> renWin->AddRenderer(ren);<br>
><br>
> ren->Render();<br>
> renWin->Render();<br>
><br>
> where 'ren' is a vtkRenderer object, ‘renWin’ is a vtkRenderWindow object,<br>
> and 'landmarks' is an array stores vtk point IDs.<br>
><br>
> Can anybody help me with this? I'll be very grateful.<br>
><br>
> Thank you all so much.<br>
><br>
> Bests<br>
> Wenlong<br>
><br>
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</blockquote></div><br>