Animation of a series of 4x4 matrix transformations using programmable filters

Dear all,

I have an STL file that I would like to transform it via a series of 4x4 matrices, and make an animation at each time point. I was able to put together the following as a Programmable Filter script, but it does not work: it only translate the whole mesh to a distance at time = 1 and then stops. Could anyone please help me?

# Code for 'Script'
import vtk
import numpy as np

def GetUpdateTimestep(algorithm):
    executive = algorithm.GetExecutive()
    outInfo = executive.GetOutputInformation(0)
    return outInfo.Get(executive.UPDATE_TIME_STEP()) \
        if outInfo.Has(executive.UPDATE_TIME_STEP()) else None

reqTime = GetUpdateTimestep(self)

src = self.GetInputDataObject(0, 0)

tfm_arr = np.array([[1, 0, 0, reqTime],
                    [0, 1, 0, 0],
                    [0, 0, 1, 0],
                    [0, 0, 0, 1]])

transform = vtk.vtkTransform()


output.GetInformation().Set(output.DATA_TIME_STEP(), reqTime)

# Code for ’RequestInformation Script’.
import numpy as np

def setOutputTimesteps(algorithm ,timesteps):
    executive = algorithm.GetExecutive()
    outInfo = executive.GetOutputInformation(0)

    # First remove existing time steps
    for timestep in timesteps :
        outInfo.Append(executive.TIME_STEPS(), timestep)
    outInfo.Append(executive.TIME_RANGE(), timesteps[0])
    outInfo.Append(executive.TIME_RANGE(), timesteps[-1])

timesteps = np.arange(10)
setOutputTimesteps(self, timesteps)

# Code for 'RequestUpdateExtent Script'
executive = self.GetExecutive()

outInfo = executive.GetOutputInformation(0)
outTimeSteps = outInfo.Get(executive.TIME_STEPS())
currentTimeStep = outInfo.Get(executive.UPDATE_TIME_STEP())
currentTimeStepIndex = outTimeSteps.index(currentTimeStep)
requestedTimeStepIndex = currentTimeStepIndex + 1
requestedTimeStep = outTimeSteps[requestedTimeStepIndex]

if requestedTimeStepIndex <= len(outTimeSteps):
    outInfo.Set(executive.UPDATE_TIME_STEP(), requestedTimeStep)