# Mark up constraints
**URL:** https://discourse.slicer.org/t/mark-up-constraints/7227
**Category:** Support
**Created:** [June 19, 2019, 6:39am UTC](https://discourse.slicer.org/t/mark-up-constraints/7227 "2019-06-19T06:39:56Z")
**Posts on this page:** 3
**Page:** 1
### Author:  [@Jainey](https://discourse.slicer.org/u/Jainey)
#### Post date: [June 19, 2019, 6:39am UTC](https://discourse.slicer.org/t/mark-up-constraints/7227/1 "2019-06-19T06:39:56Z")
Hi
Could someone please help me to write a script to keep the distance between markups fixed, please. When I add markups on my images I want them to have the same distance between some of them when I move from frame to frame in my transform sequence.
Basically, I add mak ups and transform them with my transform sequence, I d like to have their distances between each other fixed.
I have no software developing background. Could I do this with a python script pls. Are there anything already written so I can use.
Thanks
Tom
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### Author:  [@lassoan](https://discourse.slicer.org/u/lassoan)
#### Post date: [June 19, 2019, 3:57pm UTC](https://discourse.slicer.org/t/mark-up-constraints/7227/2 "2019-06-19T15:57:55Z")
You can transform the markups, harden the transform, then resample the points along the curve to be equally spaced. If you have a curve node named `C` and want control points to be at 3mm from each other then you need to type this to the Python console: `getNode('C').ResampleCurveWorld(3.0)`. Recent Slicer preview version (4.11.x) is required.
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### Author:  [@Jainey](https://discourse.slicer.org/u/Jainey)
#### Post date: [June 20, 2019, 9:17am UTC](https://discourse.slicer.org/t/mark-up-constraints/7227/3 "2019-06-20T09:17:31Z")
Thanks a lot Prof.lasso @lassoan
I will try this
Tom