# How to use vtkImplicitFunction.SetTransform()?

**URL:** https://discourse.vtk.org/t/how-to-use-vtkimplicitfunction-settransform/8785
**Category:** Support
**Tags:** python
**Created:** [June 22, 2022, 4:38pm UTC](https://discourse.vtk.org/t/how-to-use-vtkimplicitfunction-settransform/8785 "2022-06-22T16:38:35Z")
**Posts on this page:** 1
**Page:** 1

<div class="post-metadata">

### Author: ![MJJ](https://discourse.vtk.org/letter_avatar_proxy/v4/letter/m/b487fb/32.png) [@MJJ](https://discourse.vtk.org/u/MJJ)
#### Post date: [June 22, 2022, 4:38pm UTC](https://discourse.vtk.org/t/how-to-use-vtkimplicitfunction-settransform/8785/1 "2022-06-22T16:38:35Z")

</div>

I have a vtkBox with a transform set.  
However, the transform never seems to be applied to the input points. Here is the code so you can see for yourself:

```auto
import vtk

box_origin = [420, 69, 420.69]

T = vtk.vtkTransform()
T.Translate(box_origin)

box = vtk.vtkBox()
box.SetXMin([0,0,0])
box.SetXMax([1,1,1])
box.SetTransform(T.GetInverse()) 
# implicit function should now be translated to box_origin
# input points should now be translated before evaluating the function

pt = [420, 69, 420.69]
# pt should be translated to origin, resulting in function value of 0
val = box.EvaluateFunction(pt)
# val != 0
# val ends up being as if the transform was never applied to the points.
# i.e. val = norm(pt - 1) != 0
print(val)

```