Dear Gazebo Users, I am a newbie user of Gazebo. Following the tutorial described in http://gazebosim.org/tutorials?tut=build_robot&ver=1.9%2B&cat=build_robot, I get error when I try to add caster element. This is what I get:
Warning [parser.cc:713] XML Element[collision], child of element[model] not defined in SDF. Ignoring[collision]. You may have an incorrect SDF file, or an sdformat version that doesn't support this element. Warning [parser.cc:713] XML Element[visual], child of element[model] not defined in SDF. Ignoring[visual]. You may have an incorrect SDF file, or an sdformat version that doesn't support this element.
Thank you for your support!
