# Adding GCPs after step 1: initial processing?

**URL:** <https://community.pix4d.com/t/adding-gcps-after-step-1-initial-processing/8762>\
**Category:** PIX4Dmapper Questions/Troubleshooting\
**Created:** [July 25, 2019, 6:22pm UTC](https://community.pix4d.com/t/adding-gcps-after-step-1-initial-processing/8762 "2019-07-25T18:22:50Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Jonathan\_Greenberg](https://avatars.discourse-cdn.com/v4/letter/j/a3d4f5/32.png) [@Jonathan\_Greenberg](https://community.pix4d.com/u/Jonathan_Greenberg)\
**Post date:** [July 25, 2019, 6:22pm UTC](https://community.pix4d.com/t/adding-gcps-after-step-1-initial-processing/8762/1 "2019-07-25T18:22:50Z")

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Is it possible to add the .txt files containing the ground control points after running step 1? I know you can locate the ground control points on the map view rayCloud editor after step 1, so I would assume adding the .txt file after and not before step 1 would still be possible. I want to do this because I am running a batch of multiple projects and want to run step 1 first for all projects, add the GCPs after, then rerun the batch for step 2 and 3. Thanks in advance!

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**Author:** ![Kapil\_Khanal](https://sea2.discourse-cdn.com/pix4d/user_avatar/community.pix4d.com/kapil_khanal/32/304_2.png) [@Kapil\_Khanal](https://community.pix4d.com/u/Kapil_Khanal)\
**Post date:** [July 25, 2019, 10:28pm UTC](https://community.pix4d.com/t/adding-gcps-after-step-1-initial-processing/8762/2 "2019-07-25T22:28:24Z")

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Hi Jonathan,&nbsp;

You can add and mark GCPs using the rayCloud after processing step 1. GCPs can be imported in [.csv and .txt format](https://support.pix4d.com/hc/en-us/articles/202558539-Input-files#label3). To learn more about it, follow the steps explained in our support article, [How to mark GCPs in the rayCloud](https://support.pix4d.com/hc/en-us/articles/202560769-How-to-mark-GCPs-in-the-rayCloud).