# generic SetArrayComponent in a filter pipeline

**URL:** https://discourse.vtk.org/t/generic-setarraycomponent-in-a-filter-pipeline/13827
**Category:** Support
**Created:** [May 1, 2024, 1:50pm UTC](https://discourse.vtk.org/t/generic-setarraycomponent-in-a-filter-pipeline/13827 "2024-05-01T13:50:54Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![omdaniel](https://discourse.vtk.org/user_avatar/discourse.vtk.org/omdaniel/32/8538_2.png) [@omdaniel](https://discourse.vtk.org/u/omdaniel)
#### Post date: [May 1, 2024, 1:50pm UTC](https://discourse.vtk.org/t/generic-setarraycomponent-in-a-filter-pipeline/13827/1 "2024-05-01T13:50:54Z")

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I have celldata with a multi-component scalar and I cannot figure out how to set the component to use early in a filter pipeline, some filters have a setcomponent method like the contour filter but many others do not. Is there a filter that can be used to set the array component of a multi-component scalar that downstream filters will use? I see vtkMapper and subclasses have a setcomponent method but my pipeline may not involve using a mapper for non-visualization processing.

I can use the arrays CopyComponent method to copy a chosen scalar component to a single component array that is set as active scalar but I am not sure about how best trigger the pipeline to reprocess when I copy a new component to the active single component scalar.

Is there a recommended generic way to identify the component of a scalar to use in a pipeline of filters.