[ros-users] [Discourse.ros.org] [General] ROSCon 2018 Informal Meetings of Special Interest Groups

[Steve Peters]

Notes from the Gazebo Interest Group, my apologies for any errors:



Attendees:



Andrew Symington @Andrew_Symington 



Carlos Rosales Gallegos @carlosjoserg 



Musa Morena Marcusso @musamarcusso 



Ray Cole @raycoleiii 



Robert Lsch



Marcus



Ruffin @ruffsl 



Plus many Open Robotics people



Gazebo not shutting down properly



* Fixed recently in 9.4.1

* https://bitbucket.org/osrf/gazebo/pull-requests/3014/wip-address-gzserver-shutdown-speed/diff

* https://bitbucket.org/osrf/gazebo/pull-requests/3018/revert-sigterm-code/diff



Sim of wheeled robots driving in mining tunnels, but the simulation is slow and he doesnt know why



* @mjcarroll: flamegraphs?



Had a problem with robot not falling after attaching robot arm with position controller



* This was fixed in gazebo9

  * https://github.com/ros-simulation/gazebo_ros_pkgs/issues/479

  * https://bitbucket.org/osrf/gazebo/issues/2111

  * https://bitbucket.org/osrf/gazebo/pull-requests/2814/fix-issue-2111-by-providing-options-to/diff

* Workaround: use effort controller instead of position controller



How to learn more about gazebo_ros



* @azeey helped answer this



How to unthrottle simulation that could go faster than real-time



* real_time_update_rate parameter: modify in sdf world, gz tool or gui

  * Set from GUI: http://gazebosim.org/tutorials?tut=modifying_world&cat=build_world#PhysicsProperties

* ARIAC example for setting in world fie: https://bitbucket.org/osrf/ariac/src/f1c62a19374baf5f12e137f9f7329355efb1c028/osrf_gear/worlds/gear.world.template?at=master&fileviewer=file-view-default#gear.world.template-21

* From command-line: `gz physics -u 0`



Is the CreateLink function working? (written by @jrivero, not sure who asked this)



Spawning models:



* Race conditions if one needs to be spawned before the other (such as a free-floating robot on a granite table, want them to be spawned dynamically so they can be written in urdf)

  * There is a spawn_model service in gazebo_ros, but it returns too fast

  * Shane discussed a special xml tag to insert an SDF

* The spawn_model service should use quaternions instead of roll-pitch-yaw



While running lots of simulations, sometimes the simulation fails with a GLX-related error



* If its just gzserver and it doesnt use rendering, these errors can be avoided by disabling rendering in gzserver (it will also speed it up slightly) by using a bad DISPLAY variable or running inside a docker container that doesnt have nvidia-docker enabled



FBX support



* There are lots of existing models on sketchfab, often in FBX format. Bosch is interested in being able to parse FBX models.

  * Ian has worked on this, but its proprietary and complicated. We may come back to it if there is sufficient interest and support.



Modeling sea-floor



* Current workflow is to bake lots of textures into a single mesh, but its hard to export from blender.

  * Is the sea-floor like a DEM? There are some performance advantages to using DEMs.



VisualPlugins



* Underwater plumes are visualized in RVIZ with markers, but want to visualize in gzclient too. Is it possible?

  * Its easier with markers. (I didnt get all of Louises answer here)



Camera following



* Some sequence of moving camera and then follow an object caused camera to go a bit crazy



Camera Z-up



* Some people need to use Z-down, so its hard to make the camera point upside down. Andrew Symington would like to turn off the camera auto-flip



Domain randomization



* Would like to make lots of different environments with variations in which models are present, where they are located, etc. Current approach is a script that prints out different versions of world files.

  * Embedded scripting inside a world file was pretty useful in the Space Robotics Challenge for randomizing the world. It uses embedded ruby with snippets

  * https://twitter.com/chapulinaBR/status/846594820852240384

  * Template: https://bitbucket.org/osrf/srcsim/src/default/worlds/unique.world.erb

  * Instance: https://bitbucket.org/osrf/srcsim/src/default/worlds/unique.world











---

[Visit Topic](https://discourse.ros.org/t/roscon-2018-informal-meetings-of-special-interest-groups/6151/20) or reply to this email to respond.