understand the gazebo / ros concurrency model

[ivoysey]

what happens inside gaz if we place an obstacle ontop of a robot? is that configurable? if so, have we configured it the way we'd like to? how does this interact with the regions stuff?

depending on the answer to the above, do we want to have a stop-the-world kind of semantics for obstacle placement where we suspend the mission while the obstacle is getting placed?

[ivoysey]

removing this from the code freeze; i don't see it happening or mattering too much