[vtkusers] Detect vtkActor motion

[Allie Vacanti]

On Thu, Jul 27, 2017 at 1:29 PM, Koteswara Rao Ruvva via vtkusers
<vtkusers at vtk.org> wrote:
> Hello All,
>
> I want to find out whether a vtkActor is moved from its initial position. I
> want to compare vtkActor.GetMatrix() with its initial value, but I don't see
> vtkMatrix comparison API, like overloaded == or equivalent methods. Please
> suggest.

You'll either need to pull the elements of the matrix out
(aMatrix->GetData()) and compare them, or you can just check the
modification time (someMatrix->GetMTime()) to see if anything has
modified it since the last check, depending on your usecase.

HTH,
Allie