Acoording to the api gazebo 9.0 link. for example ,I can get
this->model->GetLink("link1")->WorldPose();
this->model->GetLink("link1")->WorldLinearVel();
this->model->GetLink("link1")->WorldAngularVel();
this->model->GetLink("link1")->WorldLinearAccel();
But I can not find a way to get the angle value of the base link of a floating based robot like
this->model->GetLink("link1")->WorldAngular();
this->model->GetLink("link1")->WorldTwist();
Is there any suggestion? Thank you.