After discussing the camera plugin definition in Gazebo, we can launch the complete simulation using the following command:
$ roslaunch seven_dof_arm_gazebo seven_dof_arm_world.launch
We can see the robot model with a sensor on the top of the arm, as shown here:
Figure 2 : Simulation of seven DOF arm with Asus Xtion Pro in Gazebo
We can work with the Xtion Pro data from Gazebo and check whether it provides the correct image output.