# Pipeline for rendering vtkMultiBlockDataSet

**URL:** https://discourse.paraview.org/t/pipeline-for-rendering-vtkmultiblockdataset/12785
**Category:** ParaView Support
**Created:** [August 31, 2023, 10:58am UTC](https://discourse.paraview.org/t/pipeline-for-rendering-vtkmultiblockdataset/12785 "2023-08-31T10:58:19Z")
**Posts on this page:** 6
**Page:** 1

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### Author: ![BotellaA](https://discourse.paraview.org/user_avatar/discourse.paraview.org/botellaa/32/7254_2.png) [@BotellaA](https://discourse.paraview.org/u/BotellaA)
#### Post date: [August 31, 2023, 10:58am UTC](https://discourse.paraview.org/t/pipeline-for-rendering-vtkmultiblockdataset/12785/1 "2023-08-31T10:58:19Z")

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I would like to understand how to render a vtkMultiBlockDataSet made of vertices, lines, polygons and polyhedra. I can load my vtm file into Paraview and it works but I don’t understand what pipeline steps are used to make the rendering. I tried to look into the code, but not sure where to look.

Could you explain the mapper and filters you are using to make it work?

Thanks for the help

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### Author: ![mwestphal](https://discourse.paraview.org/user_avatar/discourse.paraview.org/mwestphal/32/17_2.png) [@mwestphal](https://discourse.paraview.org/u/mwestphal)
#### Post date: [August 31, 2023, 11:04am UTC](https://discourse.paraview.org/t/pipeline-for-rendering-vtkmultiblockdataset/12785/2 "2023-08-31T11:04:19Z")

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The multiblock surfacic data is extracted using the `vtkDataSetSurfaceFilter` and displayed using the `vtkCompositePolyDataMapper`. There is not much more to it.

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### Author: ![BotellaA](https://discourse.paraview.org/user_avatar/discourse.paraview.org/botellaa/32/7254_2.png) [@BotellaA](https://discourse.paraview.org/u/BotellaA)
#### Post date: [August 31, 2023, 11:47am UTC](https://discourse.paraview.org/t/pipeline-for-rendering-vtkmultiblockdataset/12785/3 "2023-08-31T11:47:40Z")

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Thanks a lot for your quick answer!

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### Author: ![BotellaA](https://discourse.paraview.org/user_avatar/discourse.paraview.org/botellaa/32/7254_2.png) [@BotellaA](https://discourse.paraview.org/u/BotellaA)
#### Post date: [August 31, 2023, 2:50pm UTC](https://discourse.paraview.org/t/pipeline-for-rendering-vtkmultiblockdataset/12785/4 "2023-08-31T14:50:50Z")

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I may have another question. How do you activate a Scalar property on PointData of the Blocks?

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### Author: ![spyridon97](https://discourse.paraview.org/user_avatar/discourse.paraview.org/spyridon97/32/11569_2.png) [@spyridon97](https://discourse.paraview.org/u/spyridon97)
#### Post date: [August 31, 2023, 5:02pm UTC](https://discourse.paraview.org/t/pipeline-for-rendering-vtkmultiblockdataset/12785/5 "2023-08-31T17:02:38Z")

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To be more exact, the mapper used is `vtkCompositePolyDataMapper` and the surface representation (`vtkGeometryRepresentation`) is computed using `vtkPVGeometryFilter` which internally uses `vtkGeometryFilter` (it used to use `vtkDataSetSurfaceFilter`).

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### Author: ![spyridon97](https://discourse.paraview.org/user_avatar/discourse.paraview.org/spyridon97/32/11569_2.png) [@spyridon97](https://discourse.paraview.org/u/spyridon97)
#### Post date: [August 31, 2023, 5:05pm UTC](https://discourse.paraview.org/t/pipeline-for-rendering-vtkmultiblockdataset/12785/6 "2023-08-31T17:05:50Z")

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To set the scalar property for PointData of the Blocks, you need to use SetInputArrayToProcess on `vtkGeometryRepresentation`, which is exposed through the proxy using the `ColorArrayName` property.