4. Visualization in RViz

mujoco_sim provides support for visualization in RViz using the MarkerArray ROS message. This message can be accessed through the ROS topic /mujoco/visualization_marker_array. In mujoco_sim, objects within the scene are categorized as follows:

1. Robot body: These objects represent the links of the robot itself. They correspond to the body parts of the robot.

2. Spawned objects: These are objects that have been dynamically spawned during the simulation. They are created at runtime and can be added or removed as needed during the simulation.

3. World objects: These objects are not part of the robot itself but have been present in the simulation since the beginning. They define the static environment or elements in the world that the robot interacts with.

In the config file, it is necessary to specify the publish frequency for each object type. A frequency of zero indicates that the object state marker array should not be published for that particular category. Typically, the focus is on publishing the state of spawned objects that are freely movable. The state of the robot is typically visualized using the RobotModel, which provides a comprehensive representation of the robot's structure and dynamics.