[vtkusers] Help - Drawing multiple lines.

[Amy Squillacote]

Hi Prakash,

Is there any reason you cannot use two instances of vtkLineSource: one 
going from (x0, y0) to (x1, y1) and another going from (x2, y2) to (x3, 
y3)? vtkLineSource is intended to create a single straight line between 
two points.

- Amy

prakash vtk wrote:
> Hi all,
>
> How do we draw multiple lines in vtk?
>
> I want to draw a two lines intersecting perpendicularly at the center 
> in my MPR project- like 
>              x2,y2
>                 |
> x0,y0--------|--------x1,y1
>                 |
>              x3,y4                                       Here , y0 and 
> y1;  x2 and x3 are equal;
>
> I am using vtklinesource in my program.
>
> code snippet:
>
>      vtkLineSource *linea=vtkLineSource::New();
>     vtkPolyDataMapper2D *mapper=vtkPolyDataMapper2D::New();
>     vtkActor2D *actor=vtkActor2D::New();
>     vtkRenderer *render=vtkRenderer::New();
>     vtkRenderWindow *ventana=vtkRenderWindow::New();
>     vtkRenderWindowInteractor *interac=vtkRenderWindowInteractor::New();
>   
>     vtkInteractorStyleImage *imageStyle = vtkInteractorStyleImage::New();
>      linea->SetResolution(4);
>     linea->Update(); 
>     linea->GetOutput()->GetPoints()->SetNumberOfPoints(4);
>    // Try.
>     linea->GetOutput()->GetPoints()->SetPoint(0,150,0,0);
>     linea->GetOutput()->GetPoints()->SetPoint(1,150,300,0);
>     linea->GetOutput()->GetPoints()->SetPoint(2,0,150,0);
>     linea->GetOutput()->GetPoints()->SetPoint(3,300,150,0);
>     /*                                        _p
>     Dirty fix out put:                 q|_|_
>     int x=1024,y=740;                  | 
>     //Line p & q are outside the rendering window.
>     linea->GetOutput()->GetPoints()->SetPoint(0,x/2,0,0);
>     linea->GetOutput()->GetPoints()->SetPoint(1,x/2,y,0);
>     linea->GetOutput()->GetPoints()->SetPoint(2,0,y,0);
>     linea->GetOutput()->GetPoints()->SetPoint(3,0,y/2,0);
>     linea->GetOutput()->GetPoints()->SetPoint(4,x,y/2,0);*/
>
>     mapper->SetInput(linea->GetOutput());
>     actor->SetMapper(mapper);
>     actor->GetProperty()->SetColor(1.0,0.0,0.0);
>
>     render->AddActor2D(actor);
>     render->SetBackground(0.1,0.2,0.4);
>
>     ventana->AddRenderer(render);
>     interac->SetInteractorStyle(imageStyle);
>     interac->SetRenderWindow(ventana);
>    
>     ventana->Render();
>
>    interac->Render();
>   //cleanup codes..
>
>   //Code ends here...
>
> But, using vtklinesource, I am getting continuous line as attached 
> snapshot. I have fixed it. but its a dirty fix which I dont want to 
> integrate in my project. ( you can see the code for dirty fix and its 
> output in attachment).
>
> Is there any way using vtklinesource to get what I expected?
>
> vtklinesource draws a continuous line, I guess. I might be wrong here...
>
> Or Are there any other classes which help me to do this?
> Or how can I get this done in vtk?
>
> Please help me ...
>
> Regards
> Prakash,
>  
> ------------------------------------------------------------------------
>
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-- 
Amy Squillacote                    Phone: (256) 726-4839
Computer Scientist                 Fax: (256) 726-4806
CFD Research Corporation           Web: http://www.cfdrc.com
215 Wynn Drive, Suite 501
Huntsville, AL  35805