[ROS Q&A] 079 - add AR tag in gazebo

Learn how to add an AR tag 3D element in Gazebo to use it for your AR tracking programs in ROS: answers.ros.org/question/2403...
Q:add AR tag in gazebo
A: You have to generate the AR tag , then create the 3D model with the texture in blender and finally import it and spawn it in gazebo, so you can use it for tracking problems with ROS.

[@torinion]

Thank you !

[@gaslhkllo7221]

So cool that you do for us new chicken :)

[@heidy58]

I made new project in RDS and follow all the steps in this video but I stuck at URDF (minute12.04) as you mentioned in the video . how to make that ? or I miss something in the steps? as I saw in my project in catkin_ws/src just CMakeList and MarkerData.png
Could you help me sir ?
Thank you, Best regards..

[@edissonfabriciocanarortiz3487]

Excuse me sir, is it possible to use these kind of tags for developing a topological map with different rooms ?

[@TpBrass0]

Hi! This is helpful for me to generate the apriltags in gazebo.
You mentioned this is not the best way to do it, then what is the best or better way in your opinion?
Could you give me some keywords such that I can google it by myself without taking your time, thank you!

[@TheConstruct]

Hi! So yeah, what I meant by that was that the best way of doing it is with "UV Texture wrapping" and "creating seams" in Blender. This gives you more controle on how eahc texture is placed where. The way I show you here is just a fast way to have these TAGS without all the fuss. If you want to learn how to do it the more pro way check this video for example: ua-cam.com/video/vpyjqaiE0HI/v-deo.html, or this one: ua-cam.com/video/ZRF3deSIiVo/v-deo.html. Just look for Cube Texture Blender and you will get loads of tutorials on that matter. Hope it helps.

[@gautierreynes9237]

This really doesn't work. Impossible to UV unwrap...

[@seasnek7024]

Couldn't get the unwrap function to work. Kept saying object has a non-uniform scale

[@zhengwang804]

Same here... Did you figure it out?

[@user-vf3kj4rd3y]

where should be the four files located?

[@MohamedAshrafZahana]

Thanks. But it's such an annoying process for a simple tag in Gazbo!

[@ericksuzart299]

Isn't more simple to configure a plain model (with sdf and stuff) to import to gazebo after instead of URDF modeling?

[@charmindesai3730]

How to install AR packages for ROS-NOETIC

[@robolearn5639]

Thank you ! I have just one issue the marker id its returning is 255 but I have used marker of id 3. Can you tell me what I am missing

[@ephsonguakro4583]

I need help figuring out the password in order to use the "sudo" command in the RDS ROS Development Studio.

[@TheConstruct]

Hey Ephson you cannot have the root password, neither can install packages in the system. You can tell us which packages you need and we will install them for you. Or you can download the source code in your RDS zone and compile in there and use it like that. Let us know how we can help you

[@ephsonguakro4583]

I wanted to try my hands on working with ar-tags.
"sudo apt-get install ros-indigo-ar-track-alvar".
thank you.

[@TheConstruct]

We did that for you. Now the package is installed and you can use it in your coding

[@ephsonguakro4583]

Thanks a million for your help and timely response.

[@karabgut]

can I add opencv aruco marker in gazebo

[@karabgut]

yes I can, I just watched whole video.

[@soumildev3836]

@@karabgut can you ping that video link here. that would be helpful to me.

[@YoutubeFrogOfHell]

this tag doesn't get recognized for some reason
It's quite dark

[@juzhanxu4237]

I had the same problem, I found it caused by the light in the gazebo. I add a tag: '0' in model.sdf of the ar_box then the ar_box can show without the effect of light in gazebo.

[@lucasupersic97]

@@juzhanxu4237 Hi! Also my AR tag is dark. I unsuccessfully tried to put that piece of code into the .sdf file of the ar-box. I have really no clue on where I have to exactly put it. Can you help me please?

[@RobertKeszeg]

I had the same problem. I have edited the thickness of the marker so the sides were not misleading the camera. A white margin around the marker image should also help, because the marker detection relies on detecting the black squared border: "The black border facilitates its fast detection in the image and the binary codification allows its identification and the application of error detection and correction techniques." docs.opencv.org/master/d5/dae/tutorial_aruco_detection.html