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tu-darmstadt-ros-pkg / hector_quadrotor

hector_quadrotor contains packages related to modeling, control and simulation of quadrotor UAV systems.
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Can't obtain a 3D image from DepthImage (compressedDepth issue). #65

Closed Alvarodamat closed 7 years ago

Alvarodamat commented 7 years ago

Greetings, dear developers. First, thanks for this useful package, I haven't seen a better quadrotor sim before! Now, the issue: Recently I got your kinetic-devel branch of hector_quadrotor (downloaded from source) in order to obtain 3D images for an assignment. I got it, I got all the dependencies and stuff and ran the indoor SLAM demo, and, when I add a Depth Image (compressedDepth topic) I get this message in the terminal:

Compressed Depth Image Transport - Compression requires single-channel 32bit-floating point or 16bit raw depth images (input format is: rgb8).

I'm quite a newbie in this, so I don't know if it is a bug or a problem of mine, and of course, I don't know if there is any solution.

My environment is Ubuntu 16.04 Xenial, I'm ussing ROS Kinetic Kame version, Gazebo 7.0, and RViz 1.12 for Kinetic.

Some screenshots:

captura de pantalla de 2017-02-02 18-31-22

captura de pantalla de 2017-02-02 18-31-50

captura de pantalla de 2017-02-02 18-32-04

meyerj commented 7 years ago

I think the reason is that the default variant spawned from indoor_slam_gazebo.launch only has a standard RGB camera installed which uses the default gazebo_ros_camera plugin from https://github.com/ros-simulation/gazebo_ros_pkgs and does not produce depth images. The demo uses a 2D laser range finder only.

In order to spawn a quadrotor with a depth camera, you should look at the various launch file and robot description options in hector_quadrotor_gazebo or create your own drone model using urdf and appropriate Gazebo plugins. Probably spawn_quadrotor_with_kinect.launch is more or less what you want (without all the SLAM overhead):

roslaunch hector_gazebo_worlds willow_garage.launch &
roslaunch hector_quadrotor_gazebo spawn_quadrotor_with_kinect.launch &

Typically you would assemble your own application-specific launch file from the examples in the repository or other sources.

Not sure why rviz offers a selection of compression methods for depth images for the /camera/image topic, but the image_transport interface is quite generic and can contain different types of images, so the subscriber cannot know. The error message clearly states that the published format is rgb8, so no depth information.

Please consider to use http://answers.gazebosim.org/ for future questions which are not bug reports or pull requests.

Alvarodamat commented 7 years ago

Oh, thank you very much! Now I got the model running. And sorry about this thread here, if I need help again, I will head to Answers Gazebo. Thanks again!