Gazebo | Ignition | Community
Ask Your Question

NikolasE's profile - activity

2021-03-23 03:54:49 -0600 asked a question How to implement a passive caster wheel

How to implement a passive caster wheel Hello! I’m building a diff drive robot with a passive caster-wheel that has to

2020-09-08 02:50:23 -0600 asked a question How to stop gzclient from updating the database during startup?

How to stop gzclient from updating the database during startup? Hey! I installed gazebo 11.1.0 with ros2-foxy and have

2019-08-04 18:50:57 -0600 received badge  Taxonomist
2019-05-03 09:53:21 -0600 received badge  Popular Question (source)
2018-01-01 04:02:51 -0600 asked a question Are all rays of a 2d Scanner evaluated at the same time?

Are all rays of a 2d Scanner evaluated at the same time? For (fast) moving robots, the scan lines have different startin

2017-07-13 07:11:27 -0600 received badge  Famous Question (source)
2016-07-22 13:27:24 -0600 received badge  Famous Question (source)
2016-02-11 01:00:29 -0600 received badge  Famous Question (source)
2016-02-11 01:00:29 -0600 received badge  Notable Question (source)
2016-02-11 01:00:29 -0600 received badge  Popular Question (source)
2016-02-01 05:43:02 -0600 received badge  Famous Question (source)
2016-02-01 05:41:37 -0600 received badge  Famous Question (source)
2015-11-12 16:49:55 -0600 received badge  Notable Question (source)
2015-11-12 07:59:41 -0600 received badge  Enthusiast
2015-11-10 05:40:22 -0600 received badge  Popular Question (source)
2015-11-09 02:30:11 -0600 received badge  Supporter (source)
2015-11-08 13:19:13 -0600 answered a question Heightmap -- how to get sub-meter accuracy?

You could create a mesh and load that into gazebo. The easiest format is probably .obj which then can be converted to .dae e.g. via meshtool

2015-11-07 07:57:26 -0600 asked a question Perfomance of gazebo 2 with 5000 Links

Hey!

I am using gazebo 2 (with ROS Indigo) to simulate a warehouse. I have created a model with several thousand links that have a box as visual and collision object. If I select the model, it is loaded and shown in the gazebo gui where I can move it around smoothly. But as soon as I click to really add it to my scene, only maybe five objects are drawn and gazebo freezes. Is at first the object rendered only on the client with OpenGL and the after adding it to the world also on the server which is slower?

I have no problems to load the Willow Garage Model which has at least a similar complexity. I've seen that it internally uses a dae-mesh. Is using meshes recommended for larger scenes? And is there some rule of thumb how many objects can be simulated using links? Creating meshes looks more involved than creating links with boxes so I'd prefer to keep with the simpler version if there is a way to get in simulated.

Update: I also tried to open the model with just one link and 1000 visual and collision tags. Now the model was simulated after gazebo froze for about 30secs.

How should I deal with large scenes?

2015-10-31 15:37:36 -0600 received badge  Notable Question (source)
2015-10-23 14:04:27 -0600 asked a question No occlusion for projector in Gazebo 2

Hey!

I'm currently working with gazebo 2 (to work with ROS Indigo), and my current problem is with the projector. I use the standard PR2 Model and only changed the projected image (a simple cross). The major problem with the projector is the missing occlusion. It does not care if the light already hit an object, it just keeps going and illuminates objects in the shadow. defaultgzclientcamera(0)-2015-10-23T210303.596012.jpg

2015-10-19 01:14:58 -0600 asked a question How are the simulated Camera images generated?

Hey!

I'm trying to understand how the image of simulated cameras are computed on the server and on the client. My goal is to create a laser that is visible to the simulated camera (as described here ). I tried to use the GZVISIBILITYGUI/ALL-Flag but only the image shown in the GUI changed and I have no idea where to look for the code that renders the published image.

Are there really two different image generation methods (one on the client and one on the server)?

2015-10-16 04:58:08 -0600 commented question Different Visualization in Gui and ImageView

OK. Could you in the mean time give me a hint where I have to look for the code that is responsible for the visualization on the server side?

2015-10-15 20:49:28 -0600 received badge  Notable Question (source)
2015-10-14 13:22:47 -0600 received badge  Popular Question (source)
2015-10-14 12:02:37 -0600 commented question Different Visualization in Gui and ImageView

Why aren't comments shown?

2015-10-14 01:54:14 -0600 commented question Different Visualization in Gui and ImageView

But why is there a difference in the interpretation of the visibiity-flag?

2015-10-14 01:53:19 -0600 received badge  Popular Question (source)
2015-10-13 09:06:40 -0600 asked a question Different Visualization in Gui and ImageView

As already asked (here, I'm trying to simulate a line laser on my robot.

Using the GZ_VISIBILITY_GUI/GZ_VISIBILITY_ALL Flags, I managed to convince the laser to be visible in the camera as can be seen below (Gazebo 2 as I'm using ROS Indigo).

gui.png all.png

The top image was compiled after I changed the flag in rendering/LaserVisual.cc. The camera shown in the gui shows the laser plane, but it's still no visible in the Image View.

Between the two images, I only changed the LaserVisual.cc and did a sudo make install on gazebo.

Has someone else an idea?

2015-10-13 08:10:04 -0600 received badge  Scholar (source)
2015-10-13 07:49:14 -0600 received badge  Editor (source)
2015-10-13 07:48:07 -0600 commented answer Meaning of visibility Flags

Thanks! Is it possible to change the mask of the camera or the laser via parameters? Or do I really have to create my own plugin?

2015-10-13 07:22:19 -0600 asked a question How can I select the visualization for a laser?

Hey!

I'd like to write a custom visualizer for a laser scanner (so that some parts of the laserbeams are visible in simulated cameras). My plan is to copy the gazebo/gazebo/rendering/LaserVisual.cc class and adapt it to my needs. However, I'm not sure how to proceed afterwards.

How can I tell a laser which visualization-class it should use?

2015-10-13 07:00:45 -0600 asked a question Meaning of visibility Flags

Hello!

I'd like to see the endpoints of laserscanner in a camera to simulate a line laser attached to my robot. The laser is however only visible in the gazebo-GUI, but not in a simulated camera image.

I had a look around and found the LaserVisual.cc ( https://bitbucket.org/osrf/gazebo/src/439c127c6f494d8208b082c8832610ea2f67ce8c/gazebo/rendering/LaserVisual.cc?at=default&fileviewer=file-view-default ) which looks as if it is responsible for drawing the visualization of the laser scan.

My main finding was this line

this->SetVisibilityFlags(GZ_VISIBILITY_GUI);

that looks as if it is used to select who can see this visualization. Before I start to recompile the whole gazebo, I'd like to ask if it would be enough to set this flag to GZ_VISIBILITY_ALL to get the cameras to see the laser visualization.

2015-10-13 07:00:17 -0600 asked a question Meaning of visibility Flags

Hello!

I'd like to see the endpoints of laserscanner in a camera to simulate a line laser attached to my robot. The laser is however only visible in the gazebo-GUI, but not in a simulated camera image.

I had a look around and found the LaserVisual.cc ( https://bitbucket.org/osrf/gazebo/src/439c127c6f494d8208b082c8832610ea2f67ce8c/gazebo/rendering/LaserVisual.cc?at=default&fileviewer=file-view-default ) which looks as if it is responsible for drawing the visualization of the laser scan.

My main finding was this line

this->SetVisibilityFlags(GZ_VISIBILITY_GUI);

that looks as if it is used to select who can see this visualization. Before I start to recompile the whole gazebo, I'd like to ask if it would be enough to set this flag to GZ_VISIBILITY_ALL to get the cameras to see the laser visualization.

2015-10-08 03:29:49 -0600 received badge  Notable Question (source)
2015-10-08 03:29:49 -0600 received badge  Popular Question (source)
2015-10-05 10:58:01 -0600 received badge  Student (source)
2015-10-05 08:10:22 -0600 received badge  Citizen Patrol
2015-10-05 05:48:27 -0600 asked a question How can I simulate a line laser?

Hey!

We are currently developing a sheet of light sensor with (several) line lasers. To create evaluation data and to simulate our robot, I'd like to simulate the laser in gazebo. So given a camera and a pose (plane equation) for the line laser, how can I find out where the laser is visible in the camera image?

One idea was to simulate a laser scanner with a very small radial resolution and then (outside of gazebo) project the laser-scan-message back into my image. This gives nice results, however, I have to notion of occlusion so the simulated view is not correct.

It's possible in gazebo to show the laser plane of a laser scanner, but this visualization does not show up in the simulated camera.

Any ideas?