URDF, as we explained in the previous chapter, stands for Unified Robot Description Format and has an XML-compliant syntax to simulate the visual properties of a robot. This format, fitting the scope it was conceived for, does not model some of the characteristics that are needed for a dynamic simulation. More precisely, it cannot specify the following:
- The pose of the robot itself within a world.
- Joint loops (parallel linkages).
- Friction and other properties.
- Things that are not robots, such as lights, height maps, and so on.
For such reasons, an evolved XML format called Simulation Description Format (SDF) started its development as part of the Gazebo robot simulator. SDF allows us to describe objects to the environments for robot simulators, visualization, and control. Over the years, SDF has become a stable, robust, and extensible format...
