[vtkusers] Actor -- isMovable?
Piotr Byzia
piotr.byzia at gmail.com
Mon Nov 9 09:08:08 EST 2009
Hi Cory,
This sounds relatively easy, I'll confirm this next week :-)
Once again, thank you for your great support!
PS. Obviously, I wanted to reply to all, but used wrong key binding...
Regards,
Piotr Byzia
On 09.11.2009, at 13:56, Cory Quammen wrote:
> Piotr,
>
> I've replied to the list so that others may benefit from our
> discussion.
>
> I understand your question as: 1). you have a data set, 2). you've
> found a camera view you want to preserve, and 3). you want to apply
> this view to a modified version of your molecule. This is quite easy.
>
> If you are making the change to the molecule data in the same
> application instance, as long as you make sure that the first VTK
> filter in your pipeline can "see" the change (e.g., at some point one
> of the filter's Modified() methods is called), calling
> ren->GetRenderWindow()->Render() should invoke a series of updates
> that will lead to your updated model being displayed. Basically, you
> don't have to do anything but re-render. The camera view should not
> change or reset.
>
> If you want to save the camera view across program instances, you can
> get the camera matrix similar to how you would do it in the vtkActor.
> But I find it easier to do as follows:
>
> vtkCamera* cam = renderer->GetActiveCamera();
> double* position = cam->GetPosition();
> double* focalPoint = cam->GetFocalPoint();
> double* upVector = cam->GetViewUp();
>
> // Save position, focalPoint, upVector, all of which are 3-element
> double arrays, to a file or data structure
>
> To set the camera up again, just use
>
> cam->SetPosition(position);
> cam->SetFocalPoint(focalPoint);
> cam->SetViewUp(upVector);
>
> Hope that helps,
> Cory
>
> On Mon, Nov 9, 2009 at 4:05 AM, Piotr Byzia <piotr.byzia at gmail.com>
> wrote:
>> Hi Cory,
>>
>> These are incredibly helpful insights, thank you so much.
>>
>> I must re-thing this interactor style issue.
>>
>> ren->GetRenderWindow()->Render() turned out to be what I needed :)
>>
>> And one follow-up question to the transformation matrix: let's say
>> I have
>> rotated the camera on the scene with my molecule (so the initial
>> view has
>> changed using vtkInteractorStyleTrackballCamera), followed by a
>> changes in
>> some of the molecules data set (a few coordinates changes resulting
>> in a new
>> coordinates for some lines). What should be a course of action here
>> if I
>> want to preserve the view (same angle, distance etc. of the camera)
>> and
>> update the molecule actor? Similar to what you described below,
>> except that
>> after redrawing a whole structure I must apply a transformation
>> matrix to
>> the *camera* to update the view accordingly?
>> In other words, what is equivalent for the vtkActor->GetMatrix()
>> and how
>> should I update the camera view after reloading the molecule.
>> I guess this is going to be suboptimal (reloading the whole
>> structure again
>> and setting the camera again). Any suggestions on improvements are
>> more than
>> welcome ;-)
>>
>> I apologize if I'm not using the proper VTK's vocabulary here.
>>
>> Best wishes,
>> Piotr Byzia
>>
>>
>>
>>
>> On 05.11.2009, at 16:18, Cory Quammen wrote:
>>
>>> On Thu, Nov 5, 2009 at 8:46 AM, Piotr Byzia
>>> <piotr.byzia at gmail.com> wrote:
>>>>
>>>> Thank you Cory,
>>>>
>>>> This explains everything :-)
>>>>
>>>> And it'd be a perfect solution if there were some kind of offset
>>>> when
>>>> picking an object to act on.
>>>>
>>>> I couldn't find anything helpful on
>>>>
>>>> http://www.vtk.org/doc/release/4.0/html/classvtkInteractorStyleTrackballActor.html
>>>> but maybe it's some different class I should be looking in?
>>>>
>>>> In my case, actors are molecules in lines representation (sample
>>>> http://media.piotr.byzia.pl/molecule_lines.PNG) and it's hard to
>>>> target a
>>>> single line to rotate / zoom it, thus
>>>> vtkInteractorStyleTrackballCamera
>>>> was
>>>> ideal: I could rotate a molecule wherever I pressed a mouse button.
>>>>
>>>> However, imagine 2 molecules in the same window, now, I want to
>>>> be able
>>>> to
>>>> pick only one of them and rotate etc. so I can't use a
>>>> TrackballCamera
>>>> mode,
>>>> and TrackballActor is a pain with those lines...
>>>
>>> Yes, I can see how that would be a pain. I'm not sure how you can do
>>> this with mouse interaction without changing the representation of
>>> the
>>> molecule to something thicker than lines. An alternative might be to
>>> provide transformation controls in your GUI, but that is a bit more
>>> cumbersome for the user. You can manually change the orientation of
>>> the actor with vtkActor->RotateX(), ->RotateY(), ->RotateZ(), for
>>> instance.
>>>
>>>> If you still have a patience, my additional questions are, how
>>>> can I
>>>> retrieve a coordinates (the same code as previously pasted in this
>>>> message)
>>>> of all points used to draw a lines, after rotating my molecule?
>>>
>>> If you are just moving the camera, then the point positions will not
>>> change. If you are moving the actor, the points in your molecule
>>> data
>>> will also not change: all that changes is that the actor tells the
>>> GPU
>>> to apply a matrix describing the position/orientation/size of the
>>> geometry before drawing it. To get the points as they appear to be
>>> positioned in the screen, you can apply that same matrix that the
>>> actor uses to your data set. Do this by getting the transformation
>>> matrix with vtkActor->GetMatrix() and set that up in a
>>> vtkTransformFilter like this (forgive me if this isn't absolutely
>>> correct Python):
>>>
>>> transform = vtkMatrixToLinearTransform()
>>> transform.SetMatrix(actor->GetMatrix())
>>> transformFilter = vtkTransformFilter()
>>> transformFilter.SetTransform(transform)
>>> transformFilter.SetInput(moleculeGeometry)
>>> transformFilter.Update()
>>>
>>> rotatedMolecule = transformFilter.GetOutput()
>>> rotatedMolecule.Update() # might not be necessary
>>>
>>> for i in xrange(rotatedMolecule.GetNumberOfPoints()):
>>> pt = rotatedMolecule.GetPoint(i)
>>> # Do something with point
>>>
>>> This assumes you have the molecule line geometry stored in a
>>> vtkPolyData. The transform filter applies the same transformation
>>> matrix that was applied to the actor that you manipulated. I hope
>>> that
>>> I didn't make this too confusing. I am doing this very thing in an
>>> application, so I know that it works.
>>>
>>>> And the last one, as I mentioned earlier, I was able to set actor
>>>> VisibilityOff() property from my GUI, but the change is made only
>>>> after I
>>>> move mouse over the rendering window. How can I update window
>>>> right after
>>>> the property has been set?
>>>> I tried
>>>> my_actor.GetMapper().GetInput().Update()
>>>> ren.Render()
>>>> ren.Render().Update()
>>>>
>>>> ren is QVTKWindowInteractor instance. I guess this is the source
>>>> of my
>>>> problem, while there are only a few methods overloaded.
>>>
>>> Try ren->GetRenderWindow()->Render()
>>>
>>> Cory
>>>
>>>>
>>>> I'd appreciate any pointers, which method I should add there so
>>>> that
>>>> updating will work.
>>>>
>>>> Thank you,
>>>> Piotr Byzia
>>>>
>>>>
>>>>
>>>> On 05.11.2009, at 13:52, Cory Quammen wrote:
>>>>
>>>>> Piotr,
>>>>>
>>>>> The interactor style you have let's you switch between two
>>>>> modes. In
>>>>> one mode, you are moving the camera. Mouse motions in the window
>>>>> will
>>>>> affect the camera, but it will not change the actors position or
>>>>> orientation in world space. Sure, they appear to move on the
>>>>> screen,
>>>>> but what you see really comes from the camera moving. In this
>>>>> mode,
>>>>> calling PickableOff() won't have any effect because you aren't
>>>>> picking
>>>>> any actors.
>>>>>
>>>>> The other mode, however, lets you pick individual actors and
>>>>> change
>>>>> their position, orientation, and scale in world space. For this
>>>>> mode,
>>>>> you *can* pick actors and change these properties. Calling
>>>>> PickableOff() will have an effect here; it will prevent you from
>>>>> picking and subsequently modifying the actor position,
>>>>> orientation,
>>>>> and scale.
>>>>>
>>>>> In your code, the first mode is what you have. To see what the
>>>>> second
>>>>> mode is like, you might try
>>>>>
>>>>>
>>>>>
>>>>> widget_3d.GetRenderWindow().GetInteractor().GetInteractorStyle
>>>>> ().SetCurrentStyleToTrackballActor()
>>>>>
>>>>> This mode will let you manipulate individual actors, unless of
>>>>> course
>>>>> you set them to PickableOff(). This seems to me close to what
>>>>> are you
>>>>> going for.
>>>>>
>>>>> I hope that helps,
>>>>> Cory
>>>>>
>>>>> On Thu, Nov 5, 2009 at 5:48 AM, Piotr Byzia
>>>>> <piotr.byzia at gmail.com>
>>>>> wrote:
>>>>>>
>>>>>> Hi Karthik,
>>>>>> I disabled the interactor style, however I still can rotate my
>>>>>> actor
>>>>>> (by
>>>>>> the
>>>>>> mouse interaction).
>>>>>> This's what I've done:
>>>>>>
>>>>>>
>>>>>> widget_3d.GetRenderWindow().GetInteractor().GetInteractorStyle
>>>>>> ().EnabledOff()
>>>>>> my_actor.PickableOff()
>>>>>> widget_3d is an instance of
>>>>>> QVTKRenderWindowInteractor.QVTKRenderWindowInteractor(self)
>>>>>> Below is an output
>>>>>> for widget_3d.GetRenderWindow().GetInteractor
>>>>>> ().GetInteractorStyle()
>>>>>> Let me know if there is any other information which might help.
>>>>>> vtkInteractorStyleSwitch (0E995418)
>>>>>> Debug: Off
>>>>>> Modified Time: 945
>>>>>> Reference Count: 2
>>>>>> Registered Events: (none)
>>>>>> Current Renderer: 00000000
>>>>>> Default Renderer: 00000000
>>>>>> Enabled: 0
>>>>>> Priority: 0
>>>>>> Interactor: 0E9418D0
>>>>>> Key Press Activation: Off
>>>>>> Key Press Activation Value: i
>>>>>> Auto Adjust Camera Clipping Range On
>>>>>> Pick Color: (1, 0, 0)
>>>>>> CurrentRenderer: 00000000
>>>>>> Picked Renderer: (none)
>>>>>> Current Actor: (none)
>>>>>> Interactor: 0E9418D0
>>>>>> Prop Picked: No
>>>>>> State: 0
>>>>>> UseTimers: 0
>>>>>> HandleObservers: 1
>>>>>> MouseWheelMotionFactor: 1
>>>>>> Timer Duration: 10
>>>>>> CurrentStyle 0E9A3818
>>>>>> vtkInteractorStyleTrackballCamera
>>>>>> Debug: Off
>>>>>> Modified Time: 1703
>>>>>> Reference Count: 1
>>>>>> Registered Events:
>>>>>> Registered Observers:
>>>>>> vtkObserver (0E9912B8)
>>>>>> Event: 41
>>>>>> EventName: EndInteractionEvent
>>>>>> Command: 0E9A58E0
>>>>>> Priority: 0
>>>>>> Tag: 2
>>>>>> vtkObserver (0E9906B0)
>>>>>> Event: 39
>>>>>> EventName: StartInteractionEvent
>>>>>> Command: 0E9A58E0
>>>>>> Priority: 0
>>>>>> Tag: 1
>>>>>> Current Renderer: 00000000
>>>>>> Default Renderer: 00000000
>>>>>> Enabled: 0
>>>>>> Priority: 0
>>>>>> Interactor: 0E9418D0
>>>>>> Key Press Activation: Off
>>>>>> Key Press Activation Value: i
>>>>>> Auto Adjust Camera Clipping Range On
>>>>>> Pick Color: (1, 0, 0)
>>>>>> CurrentRenderer: 00000000
>>>>>> Picked Renderer: (none)
>>>>>> Current Actor: (none)
>>>>>> Interactor: 0E9418D0
>>>>>> Prop Picked: No
>>>>>> State: 0
>>>>>> UseTimers: 0
>>>>>> HandleObservers: 1
>>>>>> MouseWheelMotionFactor: 1
>>>>>> Timer Duration: 10
>>>>>> MotionFactor: 10
>>>>>>
>>>>>>
>>>>>> On 04.11.2009, at 18:25, Karthik Krishnan wrote:
>>>>>>
>>>>>> try to disable the interactor style set on teh interactor
>>>>>>
>>>>>> interactor->GetInteractorStyle()->EnabledOff()
>>>>>>
>>>>>> On Wed, Nov 4, 2009 at 10:35 AM, Piotr Byzia <piotr.byzia at gmail.com
>>>>>> >
>>>>>> wrote:
>>>>>>>
>>>>>>> Cory and Karthik,
>>>>>>>
>>>>>>> Thank you for your suggestions.
>>>>>>>
>>>>>>> By moving, I meant an interaction with a mouse.
>>>>>>> Indeed, I have no interaction style defined explicitly, but it
>>>>>>> seems
>>>>>>> that
>>>>>>> Python interface has some default one set up, because I was
>>>>>>> able to
>>>>>>> run
>>>>>>> this:
>>>>>>>
>>>>>>> lines_actor.PickableOff()
>>>>>>> print lines_actor.GetPickable()
>>>>>>> lines_actor.PickableOn()
>>>>>>> print lines_actor.GetPickable()
>>>>>>> lines_actor.SetPickable(0)
>>>>>>> print lines_actor.GetPickable()
>>>>>>>
>>>>>>> which produced:
>>>>>>> 0
>>>>>>> 1
>>>>>>> 0
>>>>>>>
>>>>>>> (I apologize if this is something obvious for you, I just
>>>>>>> started
>>>>>>> experimenting with VTK)
>>>>>>> So, vtkActor() has an interaction style by default, thus I was
>>>>>>> able to
>>>>>>> call PickableOff() on it.
>>>>>>> However it does not work, while I was able to pick and move
>>>>>>> around
>>>>>>> (rotate) lines_actor with the mouse.
>>>>>>>
>>>>>>> I had the same issue with lines_actor.DragableOff().
>>>>>>>
>>>>>>> What is surprising, lines_actor.VisibilityOff() works fine!
>>>>>>> (lines_actor
>>>>>>> was not visible on the scene)
>>>>>>>
>>>>>>> Do you possibly have ideas what can interfere with the
>>>>>>> PickableOff()
>>>>>>> ??
>>>>>>>
>>>>>>> Thanks for any suggestions,
>>>>>>> Piotr Byzia
>>>>>>>
>>>>>>>
>>>>>>> On 04.11.2009, at 14:16, Cory Quammen wrote:
>>>>>>>
>>>>>>>> Hi Piotr,
>>>>>>>>
>>>>>>>> Perhaps you could clarify what you mean by moving an actor. It
>>>>>>>> doesn't
>>>>>>>> sound like you have an interactor style that is manipulating
>>>>>>>> the
>>>>>>>> actors by picking with the mouse. If you did, however, you
>>>>>>>> could call
>>>>>>>> PickableOff() on the actor, which will prevent you from
>>>>>>>> picking it
>>>>>>>> and
>>>>>>>> thereby prevent movement of the actor.
>>>>>>>>
>>>>>>>> How exactly are you moving the actors now?
>>>>>>>>
>>>>>>>> Cory
>>>>>>>>
>>>>>>>> On Wed, Nov 4, 2009 at 7:21 AM, Piotr Byzia <piotr.byzia at gmail.com
>>>>>>>> >
>>>>>>>> wrote:
>>>>>>>>>
>>>>>>>>> Hi,
>>>>>>>>>
>>>>>>>>> I want to set an actor to be movable or non-movable,
>>>>>>>>> depending on
>>>>>>>>> settings
>>>>>>>>> which I control through PyQT GUI.
>>>>>>>>> In other words, having a few actors on the scene I want to set
>>>>>>>>> checkboxes in
>>>>>>>>> my GUI that would freeze a given actor, and the rest of them
>>>>>>>>> to
>>>>>>>>> react
>>>>>>>>> as
>>>>>>>>> usual to the mouse movements / clicks.
>>>>>>>>>
>>>>>>>>> Regarding visibility of the actor I'm using
>>>>>>>>> GetProperty().SetOpacity(0.0) on
>>>>>>>>> an instance of any given actor.
>>>>>>>>> I can't see anything related to movement in the GetProperty()
>>>>>>>>> properties, I
>>>>>>>>> believe it's somewhere else?
>>>>>>>>>
>>>>>>>>> Here are most important parts of the code I'm using to
>>>>>>>>> generate a
>>>>>>>>> single
>>>>>>>>> actor:
>>>>>>>>>
>>>>>>>>> self.ren = vtk.vtkRenderer()
>>>>>>>>> self.ren.SetBackground(0, 0, 0)
>>>>>>>>> self.widget_3d.GetRenderWindow().AddRenderer(self.ren)
>>>>>>>>>
>>>>>>>>> apd=vtk.vtkAppendPolyData()
>>>>>>>>>
>>>>>>>>> for i in xrange(len(coordinates)):
>>>>>>>>> line=vtk.vtkLineSource()
>>>>>>>>>
>>>>>>>>> line.SetPoint1(coordinates[i][0]) # 1st atom coordinates
>>>>>>>>> for a
>>>>>>>>> given
>>>>>>>>> bond
>>>>>>>>> line.SetPoint2(coordinates[i][1]) # 2nd atom coordinates
>>>>>>>>> for a
>>>>>>>>> given
>>>>>>>>> bond
>>>>>>>>> line.SetResolution(21)
>>>>>>>>> apd.AddInput(line.GetOutput())
>>>>>>>>>
>>>>>>>>> mapper = vtk.vtkPolyDataMapper()
>>>>>>>>> mapper.SetInput(apd.GetOutput())
>>>>>>>>> lines_actor = vtk.vtkActor()
>>>>>>>>> lines_actor.SetMapper(mapper)
>>>>>>>>> lines_actor.GetProperty().SetColor(0.7, 0.0, 0.0)
>>>>>>>>> lines_actor.GetProperty().SetOpacity(1.0)
>>>>>>>>>
>>>>>>>>> self.ren.AddActor(lines_actor)
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> I found SetCurrentStyleToTrackballActor(), but I want to
>>>>>>>>> control
>>>>>>>>> this
>>>>>>>>> behavior from my GUI.
>>>>>>>>> Besides, trackball mode is very inconvenient in my case, with
>>>>>>>>> molecules
>>>>>>>>> in
>>>>>>>>> "lines" representation (it's hard to pick a single line).
>>>>>>>>>
>>>>>>>>> Thanks,
>>>>>>>>> Piotr Byzia
>>>>>>>>> _______________________________________________
>>>>>>>>> Powered by www.kitware.com
>>>>>>>>>
>>>>>>>>> Visit other Kitware open-source projects at
>>>>>>>>> http://www.kitware.com/opensource/opensource.html
>>>>>>>>>
>>>>>>>>> Please keep messages on-topic and check the VTK FAQ at:
>>>>>>>>> http://www.vtk.org/Wiki/VTK_FAQ
>>>>>>>>>
>>>>>>>>> Follow this link to subscribe/unsubscribe:
>>>>>>>>> http://www.vtk.org/mailman/listinfo/vtkusers
>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>> --
>>>>>>>> Cory Quammen
>>>>>>>> Center for Computer Integrated Systems for Microscopy and
>>>>>>>> Manipulation
>>>>>>>> (CISMM)
>>>>>>>> Department of Computer Science
>>>>>>>> University of North Carolina at Chapel Hill
>>>>>>>> http://www.cs.unc.edu/~cquammen
>>>>>>>
>>>>>>> _______________________________________________
>>>>>>> Powered by www.kitware.com
>>>>>>>
>>>>>>> Visit other Kitware open-source projects at
>>>>>>> http://www.kitware.com/opensource/opensource.html
>>>>>>>
>>>>>>> Please keep messages on-topic and check the VTK FAQ at:
>>>>>>> http://www.vtk.org/Wiki/VTK_FAQ
>>>>>>>
>>>>>>> Follow this link to subscribe/unsubscribe:
>>>>>>> http://www.vtk.org/mailman/listinfo/vtkusers
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Cory Quammen
>>>>> Center for Computer Integrated Systems for Microscopy and
>>>>> Manipulation
>>>>> (CISMM)
>>>>> Department of Computer Science
>>>>> University of North Carolina at Chapel Hill
>>>>> http://www.cs.unc.edu/~cquammen
>>>>
>>>>
>>>
>>>
>>>
>>> --
>>> Cory Quammen
>>> Center for Computer Integrated Systems for Microscopy and
>>> Manipulation
>>> (CISMM)
>>> Department of Computer Science
>>> University of North Carolina at Chapel Hill
>>> http://www.cs.unc.edu/~cquammen
>>
>>
>
>
>
> --
> Cory Quammen
> Center for Computer Integrated Systems for Microscopy and
> Manipulation (CISMM)
> Department of Computer Science
> University of North Carolina at Chapel Hill
> http://www.cs.unc.edu/~cquammen
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