[Paraview] Is the VIEW-UP vector updated automatically?

[Kazuyoshi Furutaka]

Dear Utkarsh,

Thanks for your mail.

From: Utkarsh Ayachit <utkarsh.ayachit at kitware.com>
Subject: Re: [Paraview] Is the VIEW-UP vector updated automatically?
Date: Thu, 2 Oct 2014 16:00:33 -0400

> Yes, vtkCamera does often update its itself. Look at vtkCamera.cxx [1].
> 
> [1] https://github.com/Kitware/VTK/blob/83be7b1b77a6bfbf296ccaa5155cec57d0c77a8c/Rendering/Core/vtkCamera.cxx

Then, how does the following happen?


> On Thu, Oct 2, 2014 at 2:18 AM, Kazuyoshi Furutaka
> <furutaka.kazuyoshi at jaea.go.jp> wrote:
>> From Python Shell, I got the following result:
>>
>> ...resetting...
>> Python 2.7.5 (default, Sep 25 2014, 13:58:10)
>> [GCC 4.8.3 20140911 (Red Hat 4.8.3-7)] on linux2
>>>>> from paraview.simple import *
>>>>> box=Box()
>>>>> Show(box)
>> <paraview.servermanager.CompositeMultiSliceRepresentation object at 0xad91dcc>
>>>>> cam=GetActiveCamera()
>>>>> cam.SetPosition(0,3,3)
>>>>> Render()
>> <paraview.servermanager.SliceView object at 0xad91bac>
>>>>> cam.GetViewUp()
>> (0.0, 1.0, 0.0)
>>>>>

My understanding from the "Figure 3-11 Camera attributes"
of `The Visualization Toolkit (4th ed.)' is that the view-up
vector always points upward to the camera and should always
be normal to the direction of projection (and therefore
parallel to the SCREEN).  Is this correct?  Do I misunderstand
something?


Thanks, 
Kazuyoshi
--
Kazuyoshi Furutaka
furutaka _dot_ kazuyoshi _at_ jaea _dot_ go _dot_ jp