simulation problem

[altshuler]

Hi,
I'm trying to launch the project in simulation mode.
I'm using
roslaunch svo_ros intel_aero.launch and
roslaunch offboard_control simulation.launch.

But only empty world started in Gazebo,
and the drone starts to perform marker searching pattern.
There is no environment and no camera input observed.
Is there needed some additional packages to simulate
the world and camera inputs as shown in example video.