# Tie points disappeared

**URL:** <https://community.pix4d.com/t/tie-points-disappeared/26258>\
**Category:** PIX4Dmapper\
**Created:** [April 28, 2023, 3:27pm UTC](https://community.pix4d.com/t/tie-points-disappeared/26258 "2023-04-28T15:27:41Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![abel\_rozsas](https://avatars.discourse-cdn.com/v4/letter/a/91b2a8/32.png) [@abel\_rozsas](https://community.pix4d.com/u/abel_rozsas)\
**Post date:** [April 28, 2023, 3:27pm UTC](https://community.pix4d.com/t/tie-points-disappeared/26258/1 "2023-04-28T15:27:41Z")

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Hey all,

I am new to PIX4Dmapper. So sorry if this is very basic.

Why do I see nothing in the rayCloud view?

I added the photos. I did the initial processing. The tie points appeared. Then I clicked something in the View panel, and the tie points disappeared. And I cannot get them back. I restarted the software, and rerun the Initial processing. The layer is turned on.

 ![2023-04-28 17_19_53-Pix4Ddiscovery - Non Commercial - 0316 alsonmedi without GCPs](https://global.discourse-cdn.com/pix4d/original/2X/3/3f74a9a5118278922683e179dcfb5ae42f9b6022.jpeg)

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**Author:** ![Yoko\_Rader](https://avatars.discourse-cdn.com/v4/letter/y/51bf81/32.png) [@Yoko\_Rader](https://community.pix4d.com/u/Yoko_Rader)\
**Post date:** [May 1, 2023, 9:52pm UTC](https://community.pix4d.com/t/tie-points-disappeared/26258/2 "2023-05-01T21:52:13Z")

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Hi abel\_rozsas,

What coordinate system is the GCPS in? Would you be able to attach the quality report for a more in-depth look?

I’ve seen this happen when the GCPs are in an arbitrary coordinate system. The GCPs will show up in a different location than your photos. You will need to mark them before they will match up together. Follow the step by step in this article: [How to compute the site calibration for GCPs in an Arbitrary Coodinate System in Pix4Dmapper](https://support.pix4d.com/hc/en-us/articles/204515169-How-to-compute-the-Site-Calibration-for-GCPs-in-an-Arbitrary-Coordinate-System-PIX4Dmapper)

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**Author:** ![abel\_rozsas](https://avatars.discourse-cdn.com/v4/letter/a/91b2a8/32.png) [@abel\_rozsas](https://community.pix4d.com/u/abel_rozsas)\
**Post date:** [May 5, 2023, 11:28am UTC](https://community.pix4d.com/t/tie-points-disappeared/26258/3 "2023-05-05T11:28:20Z")

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Hello Yoko,

Thanks for your email.

It seems that I input the GCP data in the wrong coordinate system. So the photos were located in Europe and the GCPs in Africa.

Thanks for your help.

Best,  
Abel