# how to get raw point from CPR

**URL:** https://discourse.vtk.org/t/how-to-get-raw-point-from-cpr/13486
**Category:** vtk.js
**Tags:** code, vtkjs
**Created:** [March 8, 2024, 9:55am UTC](https://discourse.vtk.org/t/how-to-get-raw-point-from-cpr/13486 "2024-03-08T09:55:09Z")
**Posts on this page:** 1
**Page:** 1

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### Author: ![zfzlzh](https://discourse.vtk.org/user_avatar/discourse.vtk.org/zfzlzh/32/8540_2.png) [@zfzlzh](https://discourse.vtk.org/u/zfzlzh)
#### Post date: [March 8, 2024, 9:55am UTC](https://discourse.vtk.org/t/how-to-get-raw-point-from-cpr/13486/1 "2024-03-08T09:55:09Z")

</div>

i created CPR view follows the ImageCPRMapper example,  
and bind the onLeftButtonPress event to the interactor to get the coordinates of the click,  
I used openGLRenderWindow’s displayToWorld method to transform the coordinates,  
but this coordinate is not positioned correctly on the view of the original graph.

How do I calculate the points of the world coordinates on the original view from the points of the world coordinates on the CPR view?

thanks!