Beginning Filters Python

Introduction

ParaView filters

This usecase shows a user how to use filters to modify the display of data.

All filter examples assume that the user starts with a new model. To start over, go to the menu item Edit → Delete All, and then re-open your data.

Data is opened by going to File → Open. Example data files can be found on the ParaView web page at http://www.paraview.org.

Clip filter

<source lang="python"> >>> from paraview.simple import * >>> reader = ExodusIIReader(FileName=".../can.ex2") >>> Show(reader) >>> Render() </source> <source lang="python"> >>> clipFilter = Clip(reader) >>> Hide(reader) >>> Show(clipFilter) >>> Render() </source> <source lang="python">

1. get camera

>>> camera = GetActiveCamera() >>> camera.GetPosition()

1. figure out where you are

>>> camera.SetPosition(4.156,4.0,-36.29) >>> camera.Elevation(30) >>> camera.GetPosition() (4.1560389876787056, 19.261366923548998, -32.200729057625857) >>> camera.SetPosition(4.15603, 30, -35) >>> Render() </source> <source lang="python">

1. we can see what's going on a little better

>>> clipFilter.UseValueAsOffset = 1 >>> clipFilter.Value = 5 >>> Render() </source> <source lang="python">

1. let's change the orientation of the clip filter

>>> clipFilter.ClipType.Normal [1.0, 0.0, 0.0] >>> clipFilter.ClipType.Origin [0.0, 0.0, 0.0]

1. reset the offset value of the clip to 0

>>> clipFilter.Value = 0 >>> clipFilter.ClipType.Normal = [0,0,1] >>> Render() </source> <source lang="python"> >>> clipFilter.Value = -3 >>> Render() </source> <source lang="python"> >>> clipFilter.InsideOut = 1 >>> Render() </source>

Cell to Point/ Point to Cell filters

These filters are used to convert a data set from being cell data to being point data and vice versa. This is sometimes useful if a filter requires one type of data, and a user only has the other type of data. An example would be using can.exo. You cannot get a contour of EQPS directly, since EQPS is cell data and contour only works on points. Use filter Cell Data to Point Data first, then call contour.

Acknowledgements

Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy’s National Nuclear Security Administration under contract DE-AC04-94AL85000.