Drawing debug graphics

[KnockerPulsar]

Hello, it's me again. This time, I'm trying to do some debug graphics.

• Background: I already have some experience with UE4, I know a bit of ROS. No AirSim experience though.
• What I'm trying to accomplish: Send some points to UE4 to render them in lines. I tried looking through the docs but nothing crops up.

Any idea how to do this? I can try extending client.py, but I think there's more to do inside the AirSim plugin to receive the data and command the engine to render it. Any and all pointers are appreciated.

[wouter-heerwegh]

Hi @KnockerPulsar,

I'm not exactly sure what you mean, but Airsim basically runs a server to which you send commands. I myself do not have a lot of experience but you could try to take a look at how the cones are transmitted inside the Referee blueprint. This referee then gets accessed from the ros package (by calling CarApiBase::RefereeState).

Hope this helps!

[KnockerPulsar]

Thanks for the quick reply. I have attached an image of what I'm trying to achieve:

I'm hoping to do something similar to the lidar's debug lines but with my own lines sent from python code (if possible) The plan is:

• Get lidar readings and convert them to cones. Something similar to this is done in autonomous_example.py.
• Do some path planning algorithms on the cones, the output should be a set of points that construct a path.
• Send those points to AirSim/UE4 and draw them in the world, similar to how the lidar's lines are drawn.

The 2 big question marks for me are how to send data from python and receive it in UE4, and then how to command UE4 to draw them,

I tried doing a quick google on debug drawing in AirSim, but nothing useful came up.

[wouter-heerwegh]

You could try to do it this way, however, I think you are going to spend a lot more time than trying to plot everything in rviz.

Take a look at this. You could export meshes from the sim and draw them with the markers.

Here is an example from this repo

There are 2 topics with the exact data from the sim (marked with testing_only). If you use those, do not use the binary because there are still some bugs with the testing_only topics in there.

[mateusz-lichota]

We're not currently planning on extending the support for debug drawing inside of the simulator. I'd recommend the same thing as Wouter, namely to perform all visualizations in RVIZ