Units in formation sometimes appear to slide

[zoot]

Sometimes, one or more units in a formation fail to play its walking animation when moving:

See also: http://www.wildfiregames.com/forum/index.php?showtopic=16969

[zoot]

Savegame (and map) with a 'sliding' formation member.

[zoot]

Attached above (unitslide.tar.gz) is a savegame (and its corresponding map) in which a unit will begin 'sliding' a few seconds after loading. The unit has entity ID '46'.

Just before the unit begins sliding, ​OnMotionChanged is invoked on its UnitAI, and this subsequently leads to the unit entering a "FORMATIONMEMBER.IDLE" state prematurely (while it is still moving), which in turn disables the walking animation.

Why OnMotionChanged is invoked, I don't know, but it appears to be due to some kind of failure in UnitMotion because of the unit's path 'colliding' with a house.

[leper]

In 13079:

Stop formation members from sliding. Fixes #1823. Thanks to zoot for the test case!

[leper]

Thanks for the great test case!

[zoot]

The first case is fixed for me too, but apparently here is another one (sliding2.0adsave). A few seconds after loading the game, the unit with entity ID '1522' will begin sliding. (The unit is a ballista in the north-eastern part of the map.)

[leper]

In 13112:

Only call FinishOrder on MoveCompleted if we didn't get an error. Fix #1823.

[leper]

Replying to zoot:

The first case is fixed for me too, but apparently here is another one (sliding2.0adsave).

Thanks for providing another test case! I overlooked another case that triggered the OnMotionChanged hook, but it should be fixed now.