<br clear="all">Dear All,<br><br><br>I have a question about the pipeline update mechanism in VTK: If I call Update () on an algorithm that has as input the output of another algorithm, does the Update command propagate down the pipeline and causes a recomputation for all algorithms involved?<br>
For example, this code should calculate the gradient of the gradient magnitude (a measure of a second order derivative):<br><br> // Gradient magnitude <br> vtkImageGradientMagnitude* grad = vtkImageGradientMagnitude::New();<br>
grad->SetDimensionality( 3 );<br> grad->SetInput (this->GetMultivariateField (whichField)); <br> grad->Update ();<br><br> // Gradient of gradient magnitude<br> vtkImageGradient* gradGrad = vtkImageGradient::New();<br>
gradGrad->SetDimensionality( 3 );<br> gradGrad->SetInput (grad->GetOutput ());<br> gradGrad->Update ();<br> <br>Specifically, would I cause two computations of the gradient magnitude (first 4 lines of code) by calling Update twice?<br>
<br>Thanks!<br>Adrian<br><br>-- <br>---------------------------------------------------<br>Adrian Albert<br>School of Engineering and Science<br>Jacobs University Bremen<br>Germany<br>Tel.: 00494212003258