[vtkusers] General question to vtkAssembly

[Jan Ehrhardt]

Hi folks,

we try to implement our own classes for objects in a 3D-scene basing
on vtkActors. Among other things we want to group such objects
(dynamically).
Those object groups are implemented using vtkAssembly -- but strange
things
happen:
I can select a group from the menu and move (translate/rotate) the whole
group--
well this works.
But when I pick an actor (not the whole group! [vtkPicker::GetActor()])
the returned
actor isn´t the actor I have previously added to the assembly !!! Why
actors are copied
internally? Further all transformations (translation/rotation), which I
interactively  perform
to the actor (the picked one) are again removed, as soon as I move
another actor.
This seems a bit strange.

I want to do the following:
- dynamically grouping objects (creating groups, deleting groups)
- picking a group and moving the whole group (maybe picking by a menu)
- picking an actor from a group and moving this actor relative to the
group (picking by vtkPicker)

How does vtkAssembly work for these purposes ??

Hope you answer soon !

Regards,
                Jan

--
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Jan Ehrhardt
mailto:ehrhardt at medinf.mu-luebeck.de
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