[vtkusers] Drawing objects interactively in VTK..??

[Darshan Pai]

I don't know how to get the matrices defined . Maybe someone can help .
But vtkRenderer has some functions like DisplayToView() and ViewToWorld()
which can get you the world coordinate for that point.
The default camera has the clipping information .  You provide the depth of
the point
The world point will be <x*depth, y*depth, depth*-1*nearclipplane>

See if it works .

Regards
Darshan

On Wed, Apr 7, 2010 at 4:37 AM, Rakesh Patil <rakeshthp at in.com> wrote:

>
> Hi David,
>
> That is exactly what i want.. But how can i get the points or lines which
> are traced..?? And also it should work without any actor..
> I mean this class works only for some actors. But i need for with actor and
> without actor..
>
> Thanks
>
> Regards
> Rakesh Patil
>
>
> ---------- Original message ----------
> From:David Doria< daviddoria+vtk at gmail.com <daviddoria%2Bvtk at gmail.com> >
> Date: 06 Apr 10 17:59:52
> Subject: Re: [vtkusers] Drawing objects interactively in VTK..??
> To: Rakesh Patil
>
> On Tue, Apr 6, 2010 at 5:13 AM, Rakesh Patil wrote:
> > Hello,
> >
> > I am trying to draw a polyline interactively (with help of mouse). What
> i'm
> > doing is at every left button down event, i get the mouse position and
> store
> > it is a vector list. Later using this points am displaying on the
> rendering
> > window.
> >
> > But when i do this, i noticed the following:
> >
> > The mouse position values are totally different from the the points which
> > are displayed.. I mean, i click at one location, and it is displayed at
> far
> > end another location..
> >
> > I tried changing the coordinate system also.. Still the result is
> > unchanged..
> >
> > Any suggestions how it is to be done..??
> >
> > Thanks
> > Rakesh Patil
> >
>
> Sounds like you may need a coordinate system conversion in there
> somewhere, check out:
> http://vtk.org/Wiki/VTK/Examples/Coordinate
>
> It also sounds like you are trying to duplicate already working code in:
> http://vtk.org/Wiki/VTK/Examples/Widgets/ImageTracerWidget
>
> Thanks,
>
> David
>
>
>
> Get Yourself a cool, short *@in.com* Email ID now!<http://mail.in.com/mails/new_reg.php?utm_source=invite&utm_medium=outgoing>
>
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