[vtkusers] Help displaying Plane

[Albert Palomer]

Ok, I figured it out after going through the source code
<https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0ahUKEwi-88WI9t3OAhVCKx4KHaXuDpYQFggdMAA&url=https%3A%2F%2Fgithub.com%2FKitware%2FVTK%2Fblob%2Fmaster%2FFilters%2FSources%2FvtkPlaneSource.cxx&usg=AFQjCNF_rx55XLQfn1is2BVZGwEbVpstxQ&sig2=B-eed3UB3r37BP6ehFWkiA&bvm=bv.130731782,d.dmo&cad=rja>.
The SetPoint1 and SetPoint2 set the second point of the vector while the
first one is set by SetOrigin (by default origin [-0.5 -0.5 0] ). This
leads to the rhomboid because the two vectors of the parametric equation
 p=p0+v1*t+v2*s are computed as in v1 = point1 - origin and v2 = point2 -
origin.  So if you chose Point1 to be only in the X direction and point 2
to the Y (which in my mind is what should give a square) gives a rhomboid
because the director vectors of the plane are not perpendicular.

So, to define the plane I do:

// Add plane

vtkSmartPointer<vtkPlaneSource> planeSource =
vtkSmartPointer<vtkPlaneSource>::New();

// Set origin for computing the two director vectors

planeSource->SetOrigin(0,0,0);

// Set point for first director vector

planeSource->SetPoint1(x_size,0,0);

// Set point for second director vector

planeSource->SetPoint2(0,y_size,0);

// Set center

planeSource->SetCenter(5, 0.0, 0.0);

// Set normal

planeSource->SetNormal(0,0,1);


Hope this helps to anybody that might be in the same trouble.


Albert Palomer Vila

2016-08-25 17:47 GMT-07:00 Meehan, Bernard <MEEHANBT at nv.doe.gov>:

> According to the vtkPlaneSource documentation, you aren’t really supposed
> to define the plane with the SetNormal function. You are supposed to define
> it with SetPoint1, SetPoint2 and SetCenter. Another popular way of making
> the plane you want is to start out with the default plane – which is
> centered at the origin, perpendicular to the z axis, and has an x-direction
> measurement of 1, and a y-direction measurement of 1. You then use
> vtkTransform to make it the shape you want it to be.
>
> I was going to give you a working example, but ran into something that I
> didn’t understand.
> I thought this would make a plane that was 2 units in x, 1 unit in y, and
> had a center at (1, 0.5) - which seems to be what ParaView does with it …
> however it seems to come out as a parallelogram?
>
> import vtk
>
> plane = vtk.vtkPlaneSource()
> plane.SetPoint1(2.0, 0.0, 0.0)
> plane.SetPoint2(0.0, 1.0, 0.0)
> plane.SetCenter(0.0, 0.0, 0.0)
> plane.Update()
>
> mapper = vtk.vtkPolyDataMapper()
> mapper.SetInputData(plane.GetOutput())
>
> actor = vtk.vtkActor()
> actor.SetMapper(mapper)
>
> renderer = vtk.vtkRenderer()
> renderer.AddActor(actor)
>
> render_window = vtk.vtkRenderWindow()
> render_window.AddRenderer(renderer)
>
> render_window_interactor = vtk.vtkRenderWindowInteractor()
> render_window_interactor.SetRenderWindow(render_window)
>
> renderer.SetBackground(0.1, 0.3, 0.9)
> render_window_interactor.Start()
>
> _______________________________________________
> Powered by www.kitware.com
>
> Visit other Kitware open-source projects at http://www.kitware.com/
> opensource/opensource.html
>
> Please keep messages on-topic and check the VTK FAQ at:
> http://www.vtk.org/Wiki/VTK_FAQ
>
> Search the list archives at: http://markmail.org/search/?q=vtkusers
>
> Follow this link to subscribe/unsubscribe:
> http://public.kitware.com/mailman/listinfo/vtkusers
>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://public.kitware.com/pipermail/vtkusers/attachments/20160825/a28ade2b/attachment.html>