[vtkusers] Where is the actors matrix being saved?

[Ambar C]

I'm not sure I follow what you mean by 'storing Position and
Orientation'. If I set the initial position and orientation, and if
the usertransform is built when I call it from the position and
orientation, which have in turn been modified by the user's mouse,
then why would I need to store those two? Wouldn't that already have
been done within the structure of the actor? What I'm confused about
is, at what time can I call for a valid userTransform?

On Fri, Oct 1, 2010 at 3:04 PM, David Doria <daviddoria at gmail.com> wrote:
> On Fri, Oct 1, 2010 at 6:01 PM, Ambar C <ambarc at gmail.com> wrote:
>>
>> Hello,
>>
>> I'm trying to use the setUserTransform method for a vtkActor to be
>> able to record a user's changes to the actor using a mouse (which I
>> believe using vtkInteractorStyleTrackballActor as my renderer window's
>> interactor style should let me do) but after I change the position of
>> my actors using a mouse and try to access the usertransform, I see
>> that there isn't really a user transform in the first place (I see it
>> as null).
>>
>> Do I have to first set the user transform to something? I've aligned
>> my actor's initial position with the origin, and I only want the
>> userTransform to record what changes the user makes. Also, does the
>> userTransform automatically update from the trackball actor style
>> everytime some motion occurs?
>>
>> If I'm on the wrong track completely, some pointers/links would be
>> great as well :)
>>
>> Cheers,
>> Ambar
>
>
> vtkInteractorStyleTrackballActor modifies the Position and Orientation
> members of the actor. The transform is then built from these variables when
> it is needed. I would suggest you track them in the same manner (by storing
> Position and Orientation).
> David