# Is the rotation of the 3D Slicer's Transform module Euler or Quaternion?

**URL:** <https://discourse.slicer.org/t/is-the-rotation-of-the-3d-slicers-transform-module-euler-or-quaternion/11944>\
**Category:** Support\
**Created:** [June 9, 2020, 5:51am UTC](https://discourse.slicer.org/t/is-the-rotation-of-the-3d-slicers-transform-module-euler-or-quaternion/11944 "2020-06-09T05:51:35Z")\
**Posts on this page:** 1\
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**Author:** ![lassoan](https://sea2.discourse-cdn.com/flex002/user_avatar/discourse.slicer.org/lassoan/32/13_2.png) [@lassoan](https://discourse.slicer.org/u/lassoan)\
**Post date:** [June 9, 2020, 6:35am UTC](https://discourse.slicer.org/t/is-the-rotation-of-the-3d-slicers-transform-module-euler-or-quaternion/11944/2 "2020-06-09T06:35:31Z")

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Transforms module only uses 4x4 homogeneous transformation matrix for linear transforms. You can convert between these representations easily, for example by using `vtk.vtkMath.QuaternionToMatrix3x3()` and `vtk.vtkMath.Matrix3x3ToQuaternion()` methods.

Rotation angles in the Transforms module GUI simply allow incremental rotation along LR, AP, IS axes. The values displayed next to the sliders only show angle of the last rotation, therefore the displayed values do not represent the total rotation. See some more explanation at the end of [this section](https://www.slicer.org/wiki/Documentation/Nightly/Modules/Transforms#Transform_editing_and_application) in Transforms module documentation.

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