I understand (or more accurately I have followed the examples, such as its2D_5) how to calculate the stress and strain for an elastic deformation problem and probe along a line. What  I want to do now is display the surface of the material and color it by one of the (for example) strain components, such as the zz component of the strain tensor. It seems like one just has to create a pipeline in mayavi2 that uses the ExtractTensorComponent filter but for the life of me I can't figure out how to select a single component (such as the zz one of stress or strain) to use to create the surface mapping. I can change the scalar mode value in ExtractTensorComponent from "effective stress" to "component" but I don't understand how to choose a particular component.

I hate to post what is probably a simple question but lots of searching hasn't yielded an answer yet.