[vtkusers] Re nder observer events

[Karthik Krishnan]

How exactly are you doing this ? Are you invoking the "Render()"
method from a thread that is not the one instantiating the
renderwindow-interactor pair. Don't you run into nasty issues then ?



On Fri, Nov 27, 2009 at 11:39 AM, hampycalc
<i.am.tom.hampshire at googlemail.com> wrote:
>
> Hi everyone, I have been tearing my hair out trying to find a solution to
> this problem, and think I'm quite close, just not quite there yet.
> I am using a vtkCameraInterpolator to generate a fly through, similarly to
> how it is implemented here:
> http://www.vtk.org/doc/nightly/html/c2_vtk_t_3.html#c2_vtk_t_vtkCameraInterpolator
> only in C++. However, it renders very slowly due to the fact that
> vtkRenderWindow->Render() is called multiple times in the loop, creating
> multiple new threads, before it actually renders a frame. I want to check if
> the frame has been rendered correctly (and the render thread has ended)
> before making another call to vtkRenderWindow->Render(), and have attemped
> to do this by subclassing vtkCommand and attaching it to the vtkRenderer as
> an observer and look for vtkCommand::EndEvent and vtkCommand::StartEvent
> events. However, these seem to be called directly after one another,
> regardless of whether the frame has been rendered correctly. The vtkCommand
> I am using is:
>
> class vtkRenderFinish : public vtkCommand
> {
>    public:
>        static vtkRenderFinish *New()
>        {
>                        vtkRenderFinish *v = new vtkRenderFinish;
>                        v->finished = true;
>                        return v;
>        }
>
>        void Delete()
>        {
>                        delete this;
>        }
>
>        virtual void Execute(vtkObject *caller, unsigned long eventId, void*
> arguments)
>        {
>                        if (eventId == vtkCommand::EndEvent)
>                                finished = true;
>                        else if (eventId == vtkCommand::StartEvent)
>                                finished = false;
>        }
>
>        bool isFinished(){
>                        return finished;
>        }
>
> private:
>        bool finished;
> };
>
> And I am attempting to halt the vtkRenderWindow->Render() by putting:
>
> while(!vtkRenderFinish->isFinished()){
>        Sleep(10);
> }
>
> before it. The inside of this while statement is never reached, which leads
> me to believe I am not observing the correct object and/or commands.
> Any help would be greatly appreciated.
> --
> View this message in context: http://old.nabble.com/Render-observer-events-tp26544829p26544829.html
> Sent from the VTK - Users mailing list archive at Nabble.com.
>
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