NavFn now plans paths through places it should not. about navigation HOT 2 CLOSED

Just caught this happening while saving costmaps to files. This screenshot shows the navtest binary (maroon and with path, small on left) and a 4x expansion of the area in question in the gimp image program with the grayscale curve tweaked to highlight differences right at the top end of the range. The white pixels there are 255, next down are 254, and the inflated areas next down are 253. The 255 values indicate "unknown" which you can see is where the path is being planned through in the navtest image.

One thing to do is just set allow_unknown to false in navfn. However it would be even better for the unknown values to be inflated while still in the costmap.

from navigation.

It's not clear to me yet why these "unknown" values from the obstacle costmap are overwriting whatever is in the static map, but regardless it is not the fault of Navfn.

To fix this, just set rosparam /move_base/NavfnROS/allow_unknown to false, and Navfn will stop planning paths through the unknown areas.

from navigation.