2d Occupancy map from a gazebo simulation with objects

Consider a random ROS gazebo simulation with some objects. Need 2d occupancy map at a certain height x. Do not use existing plugins or something available online . Do not simulate any sensor data since the goal is to generate ground truth maps. Use information from gazebo ros-topics to get a map.


Use python or c++. Upto you. Output should be a .png or .pgm image map.