# mirroring and normals

**URL:** <https://discourse.vtk.org/t/mirroring-and-normals/2767>\
**Category:** Support\
**Created:** [March 6, 2020, 11:30am UTC](https://discourse.vtk.org/t/mirroring-and-normals/2767 "2020-03-06T11:30:29Z")\
**Posts on this page:** 1\
**Showing post:** 2

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**Author:** ![lassoan](https://discourse.vtk.org/user_avatar/discourse.vtk.org/lassoan/32/50_2.png) [@lassoan](https://discourse.vtk.org/u/lassoan)\
**Post date:** [March 9, 2020, 2:06pm UTC](https://discourse.vtk.org/t/mirroring-and-normals/2767/2 "2020-03-09T14:06:15Z")

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To position your actor, you can use origin, scale, and orientation properties of the actor.

As far as I know, UserTransform in the actor is a very low-level API. If you use us then you are expected to take care of all consequences. UserMatrix might work a bit better.

To VTK developers: It would be nice if VTK documentation would clarify what is expected when someone modifies an actor’s UserTransform or UserMatrix.

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_[View the full topic](https://discourse.vtk.org/t/mirroring-and-normals/2767)._