# Fiducial\_slam ignores fiducial\_id 0

**URL:** <https://forum.ubiquityrobotics.com/t/fiducial-slam-ignores-fiducial-id-0/415>\
**Category:** Uncategorized\
**Created:** [December 4, 2019, 2:20am UTC](https://forum.ubiquityrobotics.com/t/fiducial-slam-ignores-fiducial-id-0/415 "2019-12-04T02:20:04Z")\
**Posts on this page:** 2\
**Page:** 1

<div class="post-metadata">

**Author:** ![wongrufus](https://forum.ubiquityrobotics.com/letter_avatar_proxy/v4/letter/w/b5e925/32.png) [@wongrufus](https://forum.ubiquityrobotics.com/u/wongrufus)\
**Post date:** [December 4, 2019, 2:20am UTC](https://forum.ubiquityrobotics.com/t/fiducial-slam-ignores-fiducial-id-0/415/1 "2019-12-04T02:20:04Z")

</div>

It seems fiducial markers with id 0 are actively ignored in the mapping process. No blue line is drawn between existing markers and marker id 0, and /fiducial\_map does not publish fiducial\_id: 0

Replacing marker 0 with any other marker fixes the issue.

---

<div class="post-metadata">

**Author:** ![rohbotics](https://forum.ubiquityrobotics.com/user_avatar/forum.ubiquityrobotics.com/rohbotics/32/222_2.png) [@rohbotics](https://forum.ubiquityrobotics.com/u/rohbotics)\
**Post date:** [December 5, 2019, 9:09pm UTC](https://forum.ubiquityrobotics.com/t/fiducial-slam-ignores-fiducial-id-0/415/2 "2019-12-05T21:09:11Z")

</div>

Hi @wongrufus,

I saw that this was resolved on the Github ticket that you opened.

Good luck with your project!

Rohan