'Re: [Paraview] zooming in when using perspective projection via'

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List: paraview
Subject: Re: [Paraview] zooming in when using perspective projection via
From: Milos Ilak <ilak () mech ! kth ! se>
Date: 2010-09-28 12:30:47
Message-ID: AANLkTimok2sqe4hRF1HkjUM7XTNrskiF--NmAQY-acm_ () mail ! gmail ! com
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Hi all,

sorry to be repeating the question, but I haven't been able to figure this
out, and it is the last remaining piece I need to complete my
animations...The question is: can one use something like

V.vtkCamera.Zoom(float)

or equivalent in perspective projection? I.e., I would like to zoom in a
straightforward fashion using Python scripts, and this seems to be possible
only using parallel projection and CameraParallelScale. Regards,

Milos

On Fri, Sep 24, 2010 at 11:47 AM, Milos Ilak <ilak@mech.kth.se> wrote:

> Hi,
>
> I would like to be able to zoom during an animation using perspective
> projection. I am doing everything via a Python script. For parallel
> projection, the transformation is simple and one zooms just by changing a
> constant factor, i.e., setting the CameraParallelScale variable, and the
> camera doesn't 'move'.
>
> In parallel projection, however, one needs to change the actual camera
> position and the transformation is not that simple. Looking at the Python
> trace after zooming with the middle button, ParaView just reports the new
> camera position, but not how it was calculated.
>
> Looking at vtk documentation, there is a class called vtkCamera, which ca=
n
> be zoomed simply, just using vtkCamera.Zoom(float), which supposedly zoom=
s
> properly both in parallel and perspective projections, at least according=
 to
> the documentation. What I can't figure out is how to call a renderer usin=
g
> the vtk module and create the vtkCamera for that renderer, i.e., there wo=
uld
> be a RenderView object V of some sort, and we would just set
>
> V.vtkCamera.Zoom(float)
>
> However, there is no vtkRenderView or vtkView within the vtk Python class=
es
> provided by the module that comes with ParaView. Would someone be able to
> tell me what GetRenderView() in paraview acually calls? Or if I am headed=
 in
> the wrong direction, how should this be done properly? I hope I don't hav=
e
> to code up all the transformations by hand to obtain the new camera posit=
ion
> for parallel projection...Thanks,
>
> Milos
>
>
> --
>  Milo=C5=A1 Ilak
> Linn=C3=A9 Flow Centre
> KTH Mechanics, Stockholm
> +46(0) 8 790-7152
> www2.mech.kth.se/~ilak <http://www2.mech.kth.se/%7Eilak/>
>
>
>

[Attachment #5 (text/html)]

Hi all, sorry to be repeating the question, but I haven&#39;t been able to \
figure this out, and it is the last remaining piece I need to complete my \
animations...The question is: can one use something \
like V.vtkCamera.Zoom(float) or equivalent in perspective projection? \
I.e., I would like to zoom in a straightforward fashion using Python scripts, and \
this seems to be possible only using parallel projection and CameraParallelScale. \
Regards, Milos <div class="gmail_quote">On Fri, \
Sep 24, 2010 at 11:47 AM, Milos Ilak &lt;<a \
href="mailto:ilak@mech.kth.se">ilak@mech.kth.se</a>&gt; wrote: <blockquote \
class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt \
0pt 0.8ex; padding-left: 1ex;"> Hi, I would like to be able to zoom during an \
animation using perspective projection. I am doing everything via a Python script. \
For parallel projection, the transformation is simple and one zooms just by changing \
a constant factor, i.e., setting the CameraParallelScale variable, and the camera \
doesn&#39;t &#39;move&#39;.

In parallel projection, however, one needs to change the actual 
camera position and the transformation is not that simple. Looking at the Python \
trace after zooming with the middle button, ParaView just reports the new camera \
position, but not how it was calculated. 
 Looking at vtk documentation, there is a class called vtkCamera, 
which can be zoomed simply, just using vtkCamera.Zoom(float), which supposedly
zooms properly both in parallel and perspective projections, at least 
according to the documentation. What I can&#39;t figure out is how to call a
 renderer using the vtk module and create the vtkCamera for that 
renderer, i.e., there would be a RenderView object V of some sort, and 
we would just set 
 V.vtkCamera.Zoom(float) However, there is no vtkRenderView or
 vtkView within the vtk Python classes provided by the module that comes
 with ParaView. Would someone be able to tell me what GetRenderView() in paraview \
acually calls? Or if I am headed in the wrong direction, how should this be done \
properly? I hope I don&#39;t have to code up all the transformations by hand to \
obtain the new camera position for parallel projection...Thanks,

<br>Milos<br><font color="#888888"><br clear="all"><br>-- <br><font \
color="#888888"><div> <span style="border-collapse: separate; color: rgb(0, 0, 0); \
font-family: Helvetica; font-size: medium; font-style: normal; font-variant: normal; \
font-weight: normal; letter-spacing: normal; line-height: normal; text-indent: 0px; \
text-transform: none; white-space: normal; word-spacing: 0px;"><span \
style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; \
font-size: 12px; font-style: normal; font-variant: normal; font-weight: normal; \
letter-spacing: normal; line-height: normal; text-indent: 0px; text-transform: none; \
white-space: normal; word-spacing: 0px;"><div>

<div><span>Miloš Ilak</span></div><div>Linné Flow Centre</div><div>KTH 
Mechanics,  Stockholm  </div><div>+46(0) 8 790-7152</div><div><a \
href="http://www2.mech.kth.se/%7Eilak/" \
target="_blank">www2.mech.kth.se/~<span>ilak</span></a><br><br></div></div></span></span>
 </div></font><br>
</font></blockquote></div><br><font color="#888888"><div><span \
style="border-collapse: separate; color: rgb(0, 0, 0); font-family: Helvetica; \
font-size: medium; font-style: normal; font-variant: normal; font-weight: normal; \
letter-spacing: normal; line-height: normal; text-indent: 0px; text-transform: none; \
white-space: normal; word-spacing: 0px;"><span style="border-collapse: separate; \
color: rgb(0, 0, 0); font-family: Helvetica; font-size: 12px; font-style: normal; \
font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: \
normal; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: \
0px;"><div> <div><br></div></div></span></span>
</div></font><br>

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