SDK error when creating pipeline from C++

[GuidoBartoli]

Required Info
Camera Model	D435
Firmware Version	05.08.15.00
Operating System & Version	Ubuntu 16.04.3
Kernel Version (Linux Only)	4.13.0-36-generic
Platform	Compulab FitPC
SDK Version	2.10.1

I'm writing a ROS node for embedding Intel RealSense D435 perception into a robotics project. I installed the SDK 2 following the official guide (I encountered some problems with sudo apt-key adv --keyserver keys.gnupg.net --recv-key 6F3EFCDE because GPG key could not be retrieved, but I managed to manually download it and add to keyring).

Aside from some glitches (some warning and error popups), RealSense Viewer is working properly now.

After that, I wrote a very simple C++ test node to try fetching frames following the "rs-capture.cpp" example provided (I already updated my CMakeLists.txt to correctly compile this node):

#include <ros/ros.h>
#include <librealsense2/rs.hpp>

int main(int argc, char** argv)`
{
    // ROS initialization
    ros::init(argc, argv, "realsense_driver");
    ros::NodeHandle nh;
    ros::NodeHandle np("~");

    // Device initialization
    rs2::pipeline pipe;
    pipe.start();
    ROS_INFO("[REALSENSE] Streaming pipeline started");
    while (ros::ok())
    {
        rs2::frameset frames = pipe.wait_for_frames();
        rs2::depth_frame depth = frames.get_depth_frame();
    }

    return 0;
}

After issuing the usual catkin_make command I received many error messages (I don't report them here for brevity), so I reduced the body to just rs2::pipeline pipe; to better identify the problem and that's what I receive:

CMakeFiles/realsense_driver.dir/src/RealSenseDriverNode.cpp.o: In function `rs2::error::error(rs2_error*)':
/usr/include/librealsense2/hpp/rs_types.hpp:76: undefined reference to `rs2_get_error_message'
/usr/include/librealsense2/hpp/rs_types.hpp:78: undefined reference to `rs2_get_failed_function'
/usr/include/librealsense2/hpp/rs_types.hpp:78: undefined reference to `rs2_get_failed_function'
/usr/include/librealsense2/hpp/rs_types.hpp:79: undefined reference to `rs2_get_failed_args'
/usr/include/librealsense2/hpp/rs_types.hpp:79: undefined reference to `rs2_get_failed_args'
/usr/include/librealsense2/hpp/rs_types.hpp:80: undefined reference to `rs2_get_librealsense_exception_type'
/usr/include/librealsense2/hpp/rs_types.hpp:81: undefined reference to `rs2_free_error'
CMakeFiles/realsense_driver.dir/src/RealSenseDriverNode.cpp.o: In function `rs2::error::handle(rs2_error*)':
/usr/include/librealsense2/hpp/rs_types.hpp:127: undefined reference to `rs2_get_librealsense_exception_type'
CMakeFiles/realsense_driver.dir/src/RealSenseDriverNode.cpp.o: In function `rs2::context::context()':
/usr/include/librealsense2/hpp/rs_context.hpp:84: undefined reference to `rs2_create_context'
/usr/include/librealsense2/hpp/rs_context.hpp:84: undefined reference to `rs2_delete_context'
CMakeFiles/realsense_driver.dir/src/RealSenseDriverNode.cpp.o: In function `rs2::pipeline::pipeline(rs2::context)':
/usr/include/librealsense2/hpp/rs_pipeline.hpp:349: undefined reference to `rs2_create_pipeline'
/usr/include/librealsense2/hpp/rs_pipeline.hpp:349: undefined reference to `rs2_delete_pipeline'
collect2: error: ld returned 1 exit status

It seems a problem inside the SDK, but I really cannot understand why it cannot find its own structures and types... does anyone knows what I'm missing here?

Thanks, Best regards

[zivsha]

Hi @GuidoBartoli , These look like regular linkage issues, telling you that the linker can't find the implementation of these functions (rs2_*). It looks like you forgot to tell CMake to link the realsense2 library.

Please make sure that you properly installed librealsense, make sure that /usr/lib or /usr/local/lib has realsense2.so. You might want to try to run ldconfig to tell the linker to refresh itself.

On another note- we provide a ROS wrapper, you might want to have a look at it.

[GuidoBartoli]

Wow, what a blunder from me... I forgot to link the node to library!

add_executable(
    realsense_driver
    src/RealSenseDriverNode.cpp
)
add_dependencies(realsense_driver ${catkin_EXPORTED_TARGETS})
target_link_libraries(
    realsense_driver
    realsense2
    ${catkin_LIBRARIES}
)

Thanks for pointing it out! :)

I will take a look to the ROS wrapper, I did not know it existed.

[dmitryshendryk]

@GuidoBartoli Hello, i have the same error in Eclipse. I've binded all libraries. But still has it problem. Did you update your Makefile?

[GuidoBartoli]

@dmitryshendryk Yes, I edited the CMakeLists.txt file as I reported in my last post. The node executable was missing the linking to the realsense2 library.

[karry3775]

@zivsha I wrote a simple cpp file to check the working of librealsense2.

include <librealsense2/rs.hpp>

int main(int argc, char * argv[]){ window app(1280, 960, "CPP MUlti-Camera Example"); rs2::context ctx; return 0; }

I keep getting the undefined reference error for rs2. I run the following command g++ to_check_librealsense2.cpp -lGL -lGLU -lglut where the linkers -lGL, -lGLU and -lglut are for openGL. Before adding these linkers I was getting undefined reference for even openGL functions. Is there a similar linker function for rs2. Thanks!