[vtkusers] Help with vtkActor->SetOrigin()

[Anant Vemuri]

Thanks... But doesn't SetUserTransform() do that already... the vtk
documentation says as below...

I think I understand the problem, but not sure how to correct it... I
am attaching a transform as the base transform which means that all
the other operations such as SetOrigin(), SetScale() get overridden.


On 5/24/10, 王君臣 <wangjunchen at gmail.com> wrote:
> what you need is a multiplication (PostMultiply) of m_defaultTrf to the
> current actor transform not a replacement.
>
>
> 2010/5/24 Anant Vemuri <ajar108 at gmail.com>
>
>> Hi,
>>
>> I am trying to use myVtkActor->SetOrigin(origin) to set the origin so that
>> any rotations I apply is done about this point. This is what I do to build
>> the pipeline
>>
>>
>> void buildPipeline( )
>> {
>>     m_actor->SetMapper( m_mapper );
>>     m_actor->SetOrigin( 100, 100, 100 );
>>     m_defaultTrf->Scale(m_scale, m_scale, m_scale);
>>     m_defaultTrf->PostMultiply();
>>     m_defaultTrf->Concatenate( this->getTransform() );
>>     /// I add some more things to the m_defaultTrf
>>     .
>>     .
>>     .
>>     m_actor->SetUserTransform( m_defaultTrf );
>>     }
>>     std::cout << "\n\n\nOrigin = [" << m_actor->GetOrigin()[0] << ", " <<
>> m_actor->GetOrigin()[1] << ", " << m_actor->GetOrigin()[2] << "]\n\n\n";
>> }
>>
>> But when I apply the transform in the scene, it is not being about some
>> other point entirely. I noticed that this is the same point when I remove
>> the SetOrigin() line. But in the last line it gives me the origin as the
>> one
>> that I set a few line earlier. I am not able to figure out what is the
>> mistake. Can anyone help me?
>>
>> Thank you.
>> Anant.
>>
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>
>
> --
>


-- 
-----------
Anant S. Vemuri
email: ajar108 at gmail.com