Vtk transform matrix as python list/tuple array

lassoan · May 30, 2020, 11:54pm

You can use this function to convert a raw pointer to a Python list:

A bit more elegant, but probably not much faster or simpler method is to use DeepCopy method:

Slicer/Slicer/blob/e53e8af9c4a0b60adee28b5eca5fc1b5ff2da9ea/Base/Python/slicer/util.py#L1114-L1151


      
          def arrayFromVTKMatrix(vmatrix):
            """Return vtkMatrix4x4 or vtkMatrix3x3 elements as numpy array.
            The returned array is just a copy and so any modification in the array will not affect the input matrix.
            To set VTK matrix from a numpy array, use :py:meth:`vtkMatrixFromArray` or
            :py:meth:`updateVTKMatrixFromArray`.
            """
            from vtk import vtkMatrix4x4
            from vtk import vtkMatrix3x3
            import numpy as np
            if isinstance(vmatrix, vtkMatrix4x4):
              matrixSize = 4
            elif isinstance(vmatrix, vtkMatrix3x3):
              matrixSize = 3
            else:
              raise RuntimeError("Input must be vtk.vtkMatrix3x3 or vtk.vtkMatrix4x4")
            narray = np.eye(matrixSize)
            vmatrix.DeepCopy(narray.ravel(), vmatrix)
            return narray
          
          def vtkMatrixFromArray(narray):

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Vtk transform matrix as python list/tuple array

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