spawning before gazebo 7 is ready - model gets kicked around.
I've just upgraded for ROS-I/Gazebo2 to ROS-K/Gazebo7. If I spawn my robot at the same time Gazebo launches, it gets kicked around in the environment with random velocities. Once it settles down, I can reset the pose and it behaves as expected.
If I spawn the robot after Gazebo launches, all is good.
Any ideas why this might be happening? I've verified that my robot is not in collision with the ground plane, and I can reproduce the error in an empty world. For now, I'm launching the robot and the environment separately.
You could try launching Gazebo paused, then turning on contacts visualization, and slowly stepping through simulation. Even if it doesn't collide with the ground, it might collide with itself? In fact, what do you mean by this happening in an empty world? No other models?
@chapulina: Yes there are no other models apart from the robot and the ground plane, and self collision for the robot is turned off. I didn't try and step through the simulation 1 step at a time. Thanks for the suggestion! I'll try it out and report back.