# Apply motion equation to stl geometry.

**URL:** https://discourse.paraview.org/t/apply-motion-equation-to-stl-geometry/13327
**Category:** ParaView Support
**Created:** [November 24, 2023, 5:07pm UTC](https://discourse.paraview.org/t/apply-motion-equation-to-stl-geometry/13327 "2023-11-24T17:07:44Z")
**Posts on this page:** 2
**Page:** 1

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### Author: ![ipaulson](https://discourse.paraview.org/letter_avatar_proxy/v4/letter/i/ed8c4c/32.png) [@ipaulson](https://discourse.paraview.org/u/ipaulson)
#### Post date: [November 24, 2023, 5:07pm UTC](https://discourse.paraview.org/t/apply-motion-equation-to-stl-geometry/13327/1 "2023-11-24T17:07:44Z")

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Very new ParaView user here…

I have a DEM particle simulation of a screw auger where geometry is moving through time. Rather than export the screw stl at every timestep of the DEM simulation, I would like to just apply a motion to the screw geometry using an equation (ex: velocity = f(time)) or time-varying transform in ParaView. Ideally I import the particle data through time, the stl file at time =0, and nothing else.

Is there a relatively simple approach to doing this? Through the Calculator maybe?

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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: [November 27, 2023, 8:15am UTC](https://discourse.paraview.org/t/apply-motion-equation-to-stl-geometry/13327/2 "2023-11-27T08:15:39Z")

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> [@ipaulson](#):
>
> Is there a relatively simple approach to doing this? Through the Calculator maybe?

PythonCalculator will provide time related variables, just hover the field for a second and the doc will appear.